Powered by Deep Web Technologies
Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


1

ORISE: Dose modeling and assessments  

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

have participated include: Derivation of DCGLs for the Curtis Bay and Hammond depots Vermont Yankee Nuclear Power Station dose assessment study Radium timepiece dose modeling...

2

Assessing recovery from acidification of European surface waters in the year 2010:An evaluation of projections made with the MAGIC model in 1995  

Science Journals Connector (OSTI)

In 1999 we used the MAGIC (Model of Acidification of Groundwater In Catchments) model to project acidification of acid-sensitive European surface waters in the year 2010, given implementation of the Gothenburg Protocol to the Convention on Long-Range Transboundary Air Pollution (LRTAP). ...

Rachel Clare Helliwell; Richard F. Wright; Leah A. Jackson-Blake; Robert C. Ferrier; Julian Aherne; Bernard Jack Cosby; Christopher D. Evans; Martin Forsius; Jakub Hruska; Alan Jenkins; Pavel Krám; Jiri Kopacek; Vladimir Majer; Filip Moldan; Maximilian Posch; Jacqueline Potts; Michela Rogora; Wolfgang Schoepp

2014-10-17T23:59:59.000Z

3

Environmental Design Space model assessment  

E-Print Network (OSTI)

The Environmental Design Space (EDS) is a multi-disciplinary design tool used to explore trade-offs among aircraft fuel burn, emissions, and noise. This thesis uses multiple metrics to assess an EDS model of a Boeing 777 ...

Spindler, Phillip Michael

2007-01-01T23:59:59.000Z

4

Surface Deformation from Satellite Data and Geothermal Assessment,  

Open Energy Info (EERE)

Surface Deformation from Satellite Data and Geothermal Assessment, Surface Deformation from Satellite Data and Geothermal Assessment, Exploration and Mitigation in Imperial Valley Jump to: navigation, search OpenEI Reference LibraryAdd to library Web Site: Surface Deformation from Satellite Data and Geothermal Assessment, Exploration and Mitigation in Imperial Valley Author Mariana Eneva Published N/A, 2012 DOI Not Provided Check for DOI availability: http://crossref.org Online Internet link for Surface Deformation from Satellite Data and Geothermal Assessment, Exploration and Mitigation in Imperial Valley Citation Mariana Eneva. Surface Deformation from Satellite Data and Geothermal Assessment, Exploration and Mitigation in Imperial Valley [Internet]. 2012. N/A. N/A. [cited 2013/09/17]. Available from: http://www.energy.ca.gov/research/notices/2012-02-29_workshop/presentations/Geothermal/Eneva-Imageair_Inc_Presentation.pdf

5

Surface Water Monitoring and Assessment (Ohio) | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Surface Water Monitoring and Assessment (Ohio) Surface Water Monitoring and Assessment (Ohio) Surface Water Monitoring and Assessment (Ohio) < Back Eligibility Utility Agricultural Investor-Owned Utility State/Provincial Govt Industrial Municipal/Public Utility Local Government Tribal Government Low-Income Residential Multi-Family Residential Systems Integrator Transportation Savings Category Water Buying & Making Electricity Home Weatherization Program Info State Ohio Program Type Environmental Regulations Provider Ohio Environmental Protection Agency 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 submit credible data, thereby increasing the information base upon which to enhance, improve and

6

TEPP Planning Products Model Needs Assessment Self Assessment Document  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Planning Products Planning Products Model Needs Assessment Self Assessment Document Prepared for the Department of Energy Office of Transportation and Emergency Management 02B00215-13.p65 1 Model Needs Assessment R E V 8 - 0 7 / 2 0 1 2 T r a n s p o r t a t i o n E m e r g e n c y P r e p a r e d n e s s P r o g r a m PURPOSE The purpose of this Model Needs Assessment is to assist state, tribal, or local officials in determining emergency responder readiness for response to a transportation accident involving radioactive material. 1.0 INTRODUCTION This Model Needs Assessment was developed by the Department of Energy's Transportation Emergency Preparedness Program (TEPP) as a planning and assessment tool for state, tribal, or local government officials. To implement this Model Needs Assessment, a designated official

7

Geothermal resource conceptual models using surface exploration data | Open  

Open Energy Info (EERE)

Geothermal resource conceptual models using surface exploration data Geothermal resource conceptual models using surface exploration data Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Geothermal resource conceptual models using surface exploration data Abstract The most important element of an analysis to target a geothermal well or assess resource capacity is a resource conceptual model consistent with the available information. A common alternative approach to both targeting and assessment is to focus on a data anomaly or, in some cases, several stacked anomalies. However, even stacked anomalies are commonly misleading without support from a conceptual model. The most important element of a geothermal conceptual model is a predicted natural state isotherm pattern, especially in section view. Although inferring such an isotherm pattern at an

8

Model Fire Protection Assessment Guide  

Energy.gov (U.S. Department of Energy (DOE))

This Assessment guide covers the implementation of the DOE's responsibility of assuring that DOE and the DOE Contractors have established Fire Protection Programs that are at the level required for the area being assessed.

9

Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature  

E-Print Network (OSTI)

(WRF) and COAMPS atmospheric models. The SST-induced wind response is assessed from eight simulations of the surface wind relative to the SST gradient. #12;3 1. Introduction Positive correlations of local surfaceModeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature Natalie

Kurapov, Alexander

10

Geothermal Resource Conceptual Models Using Surface Exploration Data | Open  

Open Energy Info (EERE)

form form View source History View New Pages Recent Changes All Special Pages Semantic Search/Querying Get Involved Help Apps Datasets Community Login | Sign Up Search Page Edit with form History Facebook icon Twitter icon » Geothermal Resource Conceptual Models Using Surface Exploration Data Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Geothermal Resource Conceptual Models Using Surface Exploration Data Abstract The most important element of an analysis to target a geothermal well or assess resource capacity is a resource conceptual model consistent with the available information. A common alternative approach to both targeting and assessment is to focus on a data anomaly or, in some cases, several stacked anomalies. However, even stacked anomalies are commonly misleading without

11

Minimal model for spoof acoustoelastic surface states  

SciTech Connect

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.

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

12

ASSESSMENT OF ECONOMIC PERFORMANCE OF MODEL PREDICTIVE  

E-Print Network (OSTI)

ASSESSMENT OF ECONOMIC PERFORMANCE OF MODEL PREDICTIVE CONTROL THROUGH VARIANCE/CONSTRAINT TUNING advanced process control (APC) strategies to deal with multivariable constrained control problems with an ultimate objective towards economic optimization. Any attempt to evaluate MPC performance should therefore

Huang, Biao

13

Triazine herbcides: Ecological risk assessment in North American surface waters  

SciTech Connect

The triazine herbicides are some of the most widely used pesticides in North America. Some are found in surface waters in North America and risks to aquatic ecosystems are a possible concern. This paper presents the results of a comprehensive aquatic ecological risk assessment conducted using probabilistic risk assessment techniques. The assessment of exposure data concentrated on Midwestern us watersheds, the area of greatest triazine use in North America and showed that concentrations of some triazines rarely exceeded 20 {mu}g/L in rivers, streams, and reservoirs. The effects assessment showed that phytoplankton were the most sensitive organisms to triazines followed, in decreasing order of sensitivity, by macrophytes, benthic invertebrates, zooplankton and fish. Distribution analysis of sensitivity to atrazine showed 10th percentile of 37 {mu}g/L for LC50s in all organisms and 5.4 {mu}g/L for LC50s in algae and plants. Simazine showed 10th percentiles of 188 {mu}g/L for LC50s in all organisms and 27 {mu}g/L for LC50s in aquatic plants. Comparisons of the exposure and effects distributions showed low probabilities of exceeding the 10th percentiles of the sensitivity distributions. These results will be discussed in relation to the mechanism of action of these substances and other stressors in the environment.

Solomon, K.R. [Univ. of Guelph (Canada)

1996-10-01T23:59:59.000Z

14

Models and parameters for environmental radiological assessments  

SciTech Connect

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)

Miller, C W [ed.] [ed.

1984-01-01T23:59:59.000Z

15

Model-based safety assessments  

SciTech Connect

Sandia National Laboratories performs systems analysis of high risk, high consequence systems. In particular, Sandia is responsible for the engineering of nuclear weapons, exclusive of the explosive physics package. In meeting this responsibility, Sandia has developed fundamental approaches to safety and a process for evaluating safety based on modeling and simulation. These approaches provide confidence in the safety of our nuclear weapons. Similar concepts may be applied to improve the safety of other high consequence systems.

Carlson, D.D.; Jones, T.R.

1998-04-01T23:59:59.000Z

16

HAPTIC RENDERING OF SURFACE-TO-SURFACE SCULPTED MODEL INTERACTION  

E-Print Network (OSTI)

and second surface partial derivatives for both surfaces, an efficient kilohertz rate computation, the local Newton formulation, and the new velocity formulation. Figure 1: Well-behaved finger penetration into a surface shown by the "penetration cylinder". The velocity method and modified New- ton method return

Utah, University of

17

Does an Increase in Air Quality Models' Resolution Bring Surface Ozone Concentrations Closer to Reality?  

E-Print Network (OSTI)

Does an Increase in Air Quality Models' Resolution Bring Surface Ozone Concentrations Closer challenge for small-scale air quality modeling is the assessment of health impact and popu- lation exposure. Introduction A current trend in small-scale air quality modeling is to quantify the health impact of exposure

Menut, Laurent

18

Failure surface model for oil shale  

SciTech Connect

One promising means of recovering oil from oil shale is to retort the shale in situ. Currently, modified in situ technology requires the construction of extensive underground openings or retorts. The remaining media (structure left around these retorts must support the overburden and contain the retorting shale. A failure criterion for oil shale, which is presented in this paper, was developed so that regions in the retort structure where the shale may be approaching failure can be identified. This criterion, adapted from composite materials applications, is essentially a closed surface in six-dimensional stress space and makes it possible to describe the anisotropic nature of failure in layered materials. The failure surface can be defined by five parameters which are determined from five simple laboratory tests. The surface is developed for a 80 ml/kg kerogen content shale and its features are discussed in detail. The predictions of the model are found to be in agreement with the results of a large number of laboratory tests, including uniaxial and triaxial compression tests. One unique (for rocks) test series is discussed which involves the failure of thin-walled tubes under combined compression and torsion. Finally, it is shown how the model can be extended to include the variation of material properties with kerogen content and temperature.

Costin, L.S.

1981-08-01T23:59:59.000Z

19

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

E-Print Network (OSTI)

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

Hanson, George

20

Computable General Equilibrium Models for Sustainability Impact Assessment:  

Open Energy Info (EERE)

Computable General Equilibrium Models for Sustainability Impact Assessment: Computable General Equilibrium Models for Sustainability Impact Assessment: Status quo and prospects Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Computable General Equilibrium Models for Sustainability Impact Assessment: Status quo and prospects Agency/Company /Organization: DG Joint Research Centre, European Commission, University of Heidelberg Topics: Co-benefits assessment Resource Type: Guide/manual, Publications, Software/modeling tools User Interface: Other Website: iatools.jrc.ec.europa.eu/docs/ecol_econ_2006.pdf Computable General Equilibrium Models for Sustainability Impact Assessment: Status quo and prospects Screenshot References: Computable general equilibrium models[1] Abstract "Sustainability Impact Assessment (SIA) of economic, environmental, and

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Surface Vibrations in a Model Hcp Crystal  

E-Print Network (OSTI)

-1973. R. E. Allen, G. P. Alldredge, and F. W. de Wette, Phys. Rev. B 4, 1661 (3.971). 2R. E. Allen and F. W. de Wette, Phys. Rev. 179, 873 0.969). ..., 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...

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

1972-01-01T23:59:59.000Z

22

Diuse interface surface tension models in an expanding ow  

E-Print Network (OSTI)

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

Soatto, Stefano

23

Automatic Digital Surface Model (DSM) Generation from Linear Array Images  

E-Print Network (OSTI)

Automatic Digital Surface Model (DSM) Generation from Linear Array Images A dissertation submitted-examiner Presented by Li Zhang Zurich 2005 #12;IGP Mitteilungen Nr. 88 Automatic Digital Surface Model (DSM-906467-55-4 #12;DISS. ETH NO. 16078 Automatic Digital Surface Model (DSM) Generation from Linear Array Images

Giger, Christine

24

3D Modelling of Enhanced Surface Emission by Surface Roughening  

Science Journals Connector (OSTI)

3D FDTD is used to study the effect of surface roughening on the emission of a point source embedded in GaAs with a mirror behind the dipole. Enhancement factors of 10:1 are observed.

Buss, Ian J; Cryan, Martin J; Ho, Daniel; Craddock, Ian; Nash, Geoff; Haigh, Mary K; Railton, Chris; Rarity, John G

25

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

E-Print Network (OSTI)

Holgate S. 2002. Air pollution and health. Lancet Brunekreef2006. Bayesian modeling of air pollution health effects withExposure Models for Air Pollution Health Effects Assessment

2007-01-01T23:59:59.000Z

26

TEPP Model Needs Assessment Document | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Model Needs Assessment Document Model Needs Assessment Document TEPP Model Needs Assessment Document The purpose of this Model Needs Assessment is to assist state, tribal, or local officials in determining emergency responder readiness for response to a transportation accident involving radioactive material. This Model Needs Assessment was developed by the Department of Energy's Transportation Emergency Preparedness Program (TEPP) as a planning and assessment tool for state, tribal, or local government officials. To implement this Model Needs Assessment, a designated official from the jurisdiction will conduct a self-assessment by answering various questions. By doing so, the official will determine strengths and identify improvement areas. To support the assessment process, and any proposed recommendations for improvement, this document includes

27

Receptor modeling assessment of particle total exposure assessment methodology data  

SciTech Connect

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.

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

1999-10-15T23:59:59.000Z

28

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...

29

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

E-Print Network (OSTI)

Numerical Modeling of Nonlinear Surface Waves caused by Surface Effect Ships Dynamics problems, particularly for high-speed Surface Effect Ships (SES) such as the recently proposed Harley FastShip and/or a surface-piercing body (ship), within the framework of potential flow theory. The three

Grilli, Stéphan T.

30

Continuum Modeling of Surface Relaxation Below the Roughening Temperature  

E-Print Network (OSTI)

Continuum Modeling of Surface Relaxation Below the Roughening Temperature Robert V. Kohn Courant of a crystalline surface below the roughening temperature: Surface consists of steps and terraces. Facets form Relaxation #12;Mullins' viewpoint Fourth-order PDE model is well-established for use above the roughening

Maryland at College Park, University of

31

Accuracy of functional surfaces on comparatively modeled protein structures  

E-Print Network (OSTI)

surfaces can be accurately reproduced. We use an alpha shape based pocket algorithm to compute all pockets. Keywords Protein binding surface Á Comparative model Á Signatures of binding pockets Á Amylase Abbreviation

Dai, Yang

32

Financial and Cost Assessment Model (FICAM) | Open Energy Information  

Open Energy Info (EERE)

Financial and Cost Assessment Model (FICAM) Financial and Cost Assessment Model (FICAM) Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Financial and Cost Assessment Model (FICAM) Agency/Company /Organization: UNEP-Risoe Centre Sector: Climate Focus Area: Greenhouse Gas Topics: Finance, Baseline projection, GHG inventory Resource Type: Software/modeling tools User Interface: Spreadsheet Website: tech-action.org/models.htm Cost: Free Financial and Cost Assessment Model (FICAM) Screenshot References: FICAM[1] "The Financial and Cost Assessment Model (FICAM) evaluates the contribution of technologies and practices towards mitigation of greenhouse gases, and carries a comprehensive financial analysis." References ↑ "FICAM" Retrieved from "http://en.openei.org/w/index.php?title=Financial_and_Cost_Assessment_Model_(FICAM)&oldid=383091"

33

ESD.864 Modeling and Assessment for Policy, Spring 2011  

E-Print Network (OSTI)

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 ...

Selin, Noelle

34

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

E-Print Network (OSTI)

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

Paris-Sud XI, Université de

35

BOUSSINESQ MODELING OF SURFACE WAVES DUE TO UNDERWATER LANDSLIDES  

E-Print Network (OSTI)

BOUSSINESQ MODELING OF SURFACE WAVES DUE TO UNDERWATER LANDSLIDES DENYS DUTYKH AND HENRIK KALISCH, and viscous drag. The surface waves are studied in the Boussinesq scaling, with time-dependent bathymetry. A numerical model for the Boussinesq equations is introduced which is able to handle time-dependent bottom

Paris-Sud XI, Université de

36

BOUSSINESQ MODELING OF SURFACE WAVES DUE TO UNDERWATER LANDSLIDES  

E-Print Network (OSTI)

BOUSSINESQ MODELING OF SURFACE WAVES DUE TO UNDERWATER LANDSLIDES DENYS DUTYKH # AND HENRIK KALISCH, and viscous drag. The surface waves are studied in the Boussinesq scaling, with time­dependent bathymetry. A numerical model for the Boussinesq equations is introduced which is able to handle time­dependent bottom

37

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

38

Modeling the Performance of Engineered Systems for Closure and Near-Surface Disposal  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

performance cleanup closure performance cleanup closure M E Environmental Management Environmental Management Performance Assessment Community of Practice Technical Exchange July 13-14, 2009 Modeling the Performance of Engineered Systems for Closure and Near-Surface Disposal - Overview and Focused Discussions David S. Kosson CRESP and Vanderbilt University Tank Waste Corporate Board Meeting July 29, 2009 1 safety performance cleanup closure M E Environmental Management Environmental Management Agenda * Overview of DOE Performance Assessment Practices * Focused Discussions - Role of PA Process in Risk Communication and Decisions - Modeling Improvements - PA Assumption Validation - Uncertainty Evaluation - Evolving EPA Developments - Related IAEA Activities * Looking forward

39

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

40

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

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Modeling Of Surface Deformation From Satellite Radar Interferometry In The  

Open Energy Info (EERE)

Modeling Of Surface Deformation From Satellite Radar Interferometry In The Modeling Of Surface Deformation From Satellite Radar Interferometry In The Salton Sea Geothermal Field, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Paper: Modeling Of Surface Deformation From Satellite Radar Interferometry In The Salton Sea Geothermal Field, California Details Activities (1) Areas (1) Regions (0) Abstract: Surface deformation in the Salton Sea geothermal field is modeled using results from satellite radar interferometry, data from leveling surveys, and observations from the regional GPS network. The field is located in the Salton Trough, an active spreading center in southern California, which is traversed by the Brawley seismic zone. Deformation time series at thousands of points in the study area are obtained from a

42

2D Ising model for hydrated protein surfaces  

Science Journals Connector (OSTI)

To understand the nature of the glassy dielectric relaxation recently observed in hydrated protein powders, we model the protein surface as a 2D Ising square net, and identify frustration at the...

G. Careri

43

ORNL results for Test Case 1 of the International Atomic Energy Agency`s research program on the safety assessment of Near-Surface Radioactive Waste Disposal Facilities  

SciTech Connect

The International Atomic Energy Agency (IAEA) started the Coordinated Research Program entitled ```The Safety Assessment of Near-Surface Radioactive Waste Disposal Facilities.`` The program is aimed at improving the confidence in the modeling results for safety assessments of waste disposal facilities. The program has been given the acronym NSARS (Near-Surface Radioactive Waste Disposal Safety Assessment Reliability Study) for ease of reference. The purpose of this report is to present the ORNL modeling results for the first test case (i.e., Test Case 1) of the IAEA NSARS program. Test Case 1 is based on near-surface disposal of radionuclides that are subsequently leached to a saturated-sand aquifer. Exposure to radionuclides results from use of a well screened in the aquifer and from intrusion into the repository. Two repository concepts were defined in Test Case 1: a simple earth trench and an engineered vault.

Thorne, D.J.; McDowell-Boyer, L.M.; Kocher, D.C.; Little, C.A. [Oak Ridge National Lab., Grand Junction, CO (United States); Roemer, E.K. [Oak Ridge Inst. for Science and Education, TN (United States)

1993-07-01T23:59:59.000Z

44

Modelling receding contact lines on superhydrophobic surfaces  

E-Print Network (OSTI)

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.

B. M. Mognetti; J. M. Yeomans

2010-09-23T23:59:59.000Z

45

Assessment of architectural options for surface power generation and energy storage on human Mars missions  

E-Print Network (OSTI)

of the Martian day). Given the significant policy and sustainability advantages of solar power compared-film photovoltaic arrays and energy storage technologies that is anticipated over the coming decades, solar powerAssessment of architectural options for surface power generation and energy storage on human Mars

de Weck, Olivier L.

46

An Improved Land Surface Emissivity Parameter for Land Surface Models Using Global Remote Sensing Observations  

E-Print Network (OSTI)

Observations MENGLIN JIN Department of Atmospheric and Oceanic Science, University of Maryland, College Park Oceanic and Atmospheric Administration (NOAA) National Centers for Environmental Prediction (NCEP) model that the assumption of the constant emissivity induces errors in modeling the surface energy budget, especially over

Liang, Shunlin

47

Assessing the cumulative impacts of surface mining and coal bed methane development on shallow aquifers in the Powder River Basin, Wyoming  

SciTech Connect

Large scale surface coal mining taken place along the cropline of the Wyodak-Anderson coal seam since approximately 1977. Groundwater impacts due to surface mining of coal and other energy-related development is a primary regulatory concern and an identified Office of Surface Mining deficiency in the Wyoming coal program. The modeled aquifers are the upper unit (coal) of the Paleocene Fort Union Formation and the overlying Eocene Wasatch Formation. A regional groundwater model covering 790 square miles was constructed using MODFLOW, to simulate the impacts from three surface coal mines and coal bed methane development occurring downdip. Assessing anisotropy of the coal aquifer, quality checking of in situ aquifer tests and database quality control were precursors to modelling. Geologic data was kriged to develop the structural model of the aquifers. A Geographic Information System (GIS) was utilized to facilitate storage, analysis, display, development of input modelling arrays and assessment of hydrologic boundaries. Model output presents the predicted impacts of likely development scenarios, including impacts from coal bed methane development and surface coal mining through anticipated life of mining, and surface mining impacts independent of gas development.

Peacock, K. [Dept. of Interior, Casper, WY (United States)

1997-12-31T23:59:59.000Z

48

A Parameterization of Heterogeneous Land Surfaces for Atmospheric Numerical Models and Its Impact on Regional Meteorology  

Science Journals Connector (OSTI)

Natural land surfaces are usually heterogeneous over the resolvable scales considered in atmospheric numerical models. Therefore, model surface parameterizations that assume surface homogeneity may fail to represent the surface forcing ...

R. Avissar; R. A. Pielke

1989-10-01T23:59:59.000Z

49

Dioxins in San Francisco Conceptual Model/Impairment Assessment  

E-Print Network (OSTI)

FINAL Dioxins in San Francisco Bay Conceptual Model/Impairment Assessment Prepared by Mike Connor Partnership November 12, 2004 SFEI Contribution #309 #12;Dioxins in San Francisco Bay: Impairment Assessment. This CM/IA report examines dioxins in San Francisco Bay. Dioxins comprise a group of several hundred

50

Learning Usability Assessment Models for Web Sites  

E-Print Network (OSTI)

. Published books in the field include work by Cooper [Cooper et al. 2007], Dix [Dix 1998], Nielsen [Nielsen 2000], Norman [Norman 2002], Shneiderman [Shneiderman and Plaisant 2010], and Tidwell [Tidwell 2006]. Heuristic Evaluation When evaluating a... Web site for usability issues, usability inspection is an approach for evaluating the usability of user interfaces without those for whom the interface is designed being present [Nielsen 1994]. Usability inspection applies methods to assess...

Davis, Paul

2012-02-14T23:59:59.000Z

51

Co-benefits Risk Assessment (COBRA) Screening Model | Open Energy  

Open Energy Info (EERE)

Co-benefits Risk Assessment (COBRA) Screening Model Co-benefits Risk Assessment (COBRA) Screening Model Jump to: navigation, search Tool Summary Name: Co-benefits Risk Assessment (COBRA) Screening Model Agency/Company /Organization: United States Environmental Protection Agency Sector: Climate Complexity/Ease of Use: Moderate Website: www.epa.gov/statelocalclimate/resources/cobra.html Cost: Free Related Tools Tool for Selecting CDM Methods & Technologies Modular Applied General Equilibrium Tool (MAGNET) COMMUTER Model ... further results Find Another Tool FIND DEVELOPMENT IMPACTS ASSESSMENT TOOLS Automated tool that can be downloaded from the website. Converts emissions reductions into air quality improvements, estimates annual adverse health impacts avoided, and monetizes the value of these. Approach COBRA converts emissions reductions into air quality improvements, and

52

MURDAM1.0. Minority Utility Rate Design Assessment Model  

SciTech Connect

Econometric model simulates consumer demand response to various user-supplied, two-part tariff electricity rate designs and assesses their economic welfare impact on black, hispanic, poor and majority households.

Poyer, D.A.; Butler, J.G. [Argonne National Lab., IL (United States)

1993-01-20T23:59:59.000Z

53

A practical profile of integrated safety assessment of near-surface disposal of radwaste at  

Science Journals Connector (OSTI)

Near-surface or shallow land disposal of radioactive waste has been the primary practice at the Pakistan Institute of Nuclear Science and Technology (PINSTECH). The adopted choice of this mode of disposal has been based on a study of the site and the quality and quantity of waste generated at the 5 MW reactor with HEU fuel. Specific measures regarding the radiation safety of the workers and environmental protection have been adopted. The waste disposal operations are conducted to meet local regulatory requirements, IAEA recommendations and internationally endorsed principles such as ALARA (as low as reasonably achievable—economic, social and other relevant factors being considered). The data obtained through the years of operational and management experience have manifested the robustness of the disposal system and reliability of the disposal criterion, and have also served to further refine the latter. Consequently, confidence in the current shallow-land-burial practices has increased. Radiological safety of these practices has been assessed by addressing different aspects of the safety and disposal system. These parameters, as indices of a non-exclusive and operational safety model, are presented.

F Jan; S S Ahmad; S M Hasany; M Aslam

2007-01-01T23:59:59.000Z

54

Appendix MASS: Performance Assessment Modeling Assumptions  

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

Rock Units MASS-12.2 Historical Context of the Salado Conceptual Model MASS-12.3 The Fracture Model MASS-12.4 Flow in the DRZ MASS-12.5 Actinide Transport in the Salado MASS-13.0...

55

Posters Surface Flux Intercomparison Between the MM5 Model  

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

Posters Surface Flux Intercomparison Between the MM5 Model and Observations During the Storm-Scale Observations Regional Measurement Program-Fronts Experiment Systems Test 1992 J. Dudhia and S. P. Oncley Mesoscale and Microscale Meteorology Division Atmospheric Technology Division National Center for Atmospheric Research Boulder, Colorado Introduction Mesoscale model 5 (MM5) is being used as a data assimilation tool for the Atmospheric Radiation Measurement (ARM) Program. There is a need to verify that the model physics is consistent with observations under a range of conditions. Surface fluxes of heat, moisture, and momentum are a particular area of uncertainty in the model owing to their dependence on surface properties, some of which are time-dependent. The National Center for Atmospheric Research (NCAR)

56

Surface tension in the dilute Ising model. The Wulff construction  

E-Print Network (OSTI)

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.

Marc Wouts

2008-04-14T23:59:59.000Z

57

Surface photovoltage measurements and finite element modeling of SAW devices.  

SciTech Connect

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.

Donnelly, Christine

2012-03-01T23:59:59.000Z

58

The Whitham Equation as a Model for Surface Water Waves  

E-Print Network (OSTI)

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 tha...

Moldabayev, Daulet; Dutykh, Denys

2014-01-01T23:59:59.000Z

59

The Whitham Equation as a Model for Surface Water Waves  

E-Print Network (OSTI)

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.

Daulet Moldabayev; Henrik Kalisch; Denys Dutykh

2014-10-30T23:59:59.000Z

60

E-Print Network 3.0 - assessing local model Sample Search Results  

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

OF ENGINEERING CYBERNETICS AND ROBOTICS, 60 Summary: , 60 2009 Sofia Service Oriented Architecture of Assessment Model1 Adelina Aleksieva... Assessment Model. To achieve...

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Workshop on Carbon Sequestration Science - Modeling and Integrated Assessment  

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

Modeling and Integrated Modeling and Integrated Assessment Howard Herzog MIT Energy Laboratory May 24, 2001 Economic Assessments * Engineering analysis of CO 2 separation and capture * Economic modeling/ integrated assessment of carbon capture and sequestration * Comparison on equal basis of the major sequestration options Economic Modeling Motivation * When might carbon capture and sequestration (CCS) become competitive? * What is its potential scale? * Which technologies look most promising? . . . . And when? * How to see the potential in a general market context? Detailed Reference *Sean Biggs Thesis: S Biggs, S. D., "Sequestering Carbon from Power Plants: The Jury is Still Out," M.I.T. Masters Thesis, (2000). S http://sequestration.mit.edu/pdf/SeanBiggs.pdf What Determines Competitiveness?

62

Physical Stability of Long-Term Surface Barriers-Assessment of Potentially Disruptive Natural Events  

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

] ] a -" m HI BHI-00145 Rev. 00 Physical Stability of Long-Term Surface Barriers - Assessment of Potentially Disruptive Natural Events Authors N. R. Wing IT Hanford, Inc. F. M. Corpuz Bechtel Hanford, Inc. K. L. Petersen Pacific Northwest Laboratoy A. M. Tallman Westinghouse Hanford Company Date Published May 1995 HANFORD Prepared for the U.S. Department of Energy Office of Environmental Restoration and Waste Management Bechtel Hanford, Inc. Flichland, Washington Approved for Public Release . b q q BHI-00145 ma) Ou: NIA TSD: NIA ERA: NIA APPROVAL PAGE Title of Dccumw PHYSICAL STABILITY OF LONG-TERM SURFACE BARRIERS - ASSESSMENT OF POTE.INTI.ALLYDISRUPTIVE NATURAL Author(s): N. R. Wq, lT ~Otd, Inc. K. L. PetmerL hCi.fiC Northwest Labmtory F. M. Corpuz, Bechkl Hanford, Inc. A. M. Tai.lmaq W-owe HEUlfOd Corqnny Approvai: J. G. Zoghbi, Acting Manager, Technology Demonstration

63

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

Science Journals Connector (OSTI)

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 ...

Hongyi Li; Mark S. Wigmosta; Huan Wu; Maoyi Huang; Yinghai Ke; André M. Coleman; L. Ruby Leung

2013-06-01T23:59:59.000Z

64

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

E-Print Network (OSTI)

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 ...

Xu, L.

65

A finite difference model for free surface gravity drainage  

SciTech Connect

The unconfined gravity flow of liquid with a free surface into a well is a classical well test problem which has not been well understood by either hydrologists or petroleum engineers. Paradigms have led many authors to treat an incompressible flow as compressible flow to justify the delayed yield behavior of a time-drawdown test. A finite-difference model has been developed to simulate the free surface gravity flow of an unconfined single phase, infinitely large reservoir into a well. The model was verified with experimental results in sandbox models in the literature and with classical methods applied to observation wells in the Groundwater literature. The simulator response was also compared with analytical Theis (1935) and Ramey et al. (1989) approaches for wellbore pressure at late producing times. The seepage face in the sandface and the delayed yield behavior were reproduced by the model considering a small liquid compressibility and incompressible porous medium. The potential buildup (recovery) simulated by the model evidenced a different- phenomenon from the drawdown, contrary to statements found in the Groundwater literature. Graphs of buildup potential vs time, buildup seepage face length vs time, and free surface head and sand bottom head radial profiles evidenced that the liquid refills the desaturating cone as a flat moving surface. The late time pseudo radial behavior was only approached after exaggerated long times.

Couri, F.R.; Ramey, H.J. Jr.

1993-09-01T23:59:59.000Z

66

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

E-Print Network (OSTI)

surface downwelling solar irradiance (SSI). This method is composed by two parts: a clear-sky moduleAssessment of Heliosat-4 surface solar irradiance derived on the basis of SEVIRI-APOLLO cloud Aerospace Center (DLR), aims at estimating surface downwelling solar irradiance (SSI). It benefits from

Boyer, Edmond

67

Model and Analytic Processes for Export License Assessments  

SciTech Connect

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.

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

68

Large-scale Validation of AMIP II Land-surface Simulations: Preliminary Results for Ten Models  

SciTech Connect

This report summarizes initial findings of a large-scale validation of the land-surface simulations of ten atmospheric general circulation models that are entries in phase II of the Atmospheric Model Intercomparison Project (AMIP II). This validation is conducted by AMIP Diagnostic Subproject 12 on Land-surface Processes and Parameterizations, which is focusing on putative relationships between the continental climate simulations and the associated models' land-surface schemes. The selected models typify the diversity of representations of land-surface climate that are currently implemented by the global modeling community. The current dearth of global-scale terrestrial observations makes exacting validation of AMIP II continental simulations impractical. Thus, selected land-surface processes of the models are compared with several alternative validation data sets, which include merged in-situ/satellite products, climate reanalyses, and off-line simulations of land-surface schemes that are driven by observed forcings. The aggregated spatio-temporal differences between each simulated process and a chosen reference data set then are quantified by means of root-mean-square error statistics; the differences among alternative validation data sets are similarly quantified as an estimate of the current observational uncertainty in the selected land-surface process. Examples of these metrics are displayed for land-surface air temperature, precipitation, and the latent and sensible heat fluxes. It is found that the simulations of surface air temperature, when aggregated over all land and seasons, agree most closely with the chosen reference data, while the simulations of precipitation agree least. In the latter case, there also is considerable inter-model scatter in the error statistics, with the reanalyses estimates of precipitation resembling the AMIP II simulations more than to the chosen reference data. In aggregate, the simulations of land-surface latent and sensible heat fluxes appear to occupy intermediate positions between these extremes, but the existing large observational uncertainties in these processes make this a provisional assessment. In all selected processes as well, the error statistics are found to be sensitive to season and latitude sector, confirming the need for finer-scale analyses which also are in progress.

Phillips, T J; Henderson-Sellers, A; Irannejad, P; McGuffie, K; Zhang, H

2005-12-01T23:59:59.000Z

69

Wetting and free surface flow modeling for potting and encapsulation.  

SciTech Connect

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.

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

70

Deposition Modeling for Paint Application on Surfaces Embedded in  

E-Print Network (OSTI)

) of the paint applicator. Industrial robots are widely used for automotive paint application becauseDeposition Modeling for Paint Application on Surfaces Embedded in ¢¡¤£ David C. Conner Prasad N. Atkar Alfred A. Rizzi Howie Choset CMU-RI-TR-02-08 October 2002 Robotics Institute Carnegie Mellon

71

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 Fracture Tsvetanka Sendova and Jay R. Walton Institute for Mathematics and Its Applications, University@math.tamu.edu Abstract. In this article the problem of an interface fracture between two isotropic linear elas- tic

72

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

SciTech Connect

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.

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

73

The Community Surface Dynamics Modeling System: Experiences on Building a Collaborative Modeling Platform  

E-Print Network (OSTI)

The Community Surface Dynamics Modeling System: Experiences on Building a Collaborative Modeling VOLUNTEERISM MANY DEVELOPERS Grand Challenge: Building a Toolbox of Component Models with guidance and input Members and Governance · Tools for Collaboration 1) CSDMS Wiki 2) CSDMS Modeling Tool · Strategies

Wright, Dawn Jeannine

74

Bayesian Model Averaging in Proportional Hazard Models: Assessing the Risk of a Stroke  

E-Print Network (OSTI)

Bayesian Model Averaging in Proportional Hazard Models: Assessing the Risk of a Stroke Chris T In the context of the Cardiovascular Health Study, a comprehensive investigation into the risk factors for stroke of assessing who is at high risk for stroke. 1 Introduction Stroke is the third leading cause of death among

Volinsky, Chris

75

Models of the solvent-accessible surface of biopolymers  

SciTech Connect

Many biopolymers such as proteins, DNA, and RNA have been studied because they have important biomedical roles and may be good targets for therapeutic action in treating diseases. This report describes how plastic models of the solvent-accessible surface of biopolymers were made. Computer files containing sets of triangles were calculated, then used on a stereolithography machine to make the models. Small (2 in.) models were made to test whether the computer calculations were done correctly. Also, files of the type (.stl) required by any ISO 9001 rapid prototyping machine were written onto a CD-ROM for distribution to American companies.

Smith, R.E.

1996-09-01T23:59:59.000Z

76

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 climate policy analysis. This paper examines the representation of carbon capture and storage (CCS carbon capture and storage, 2) a natural gas combined cycle technology with carbon capture and storage 1

77

Multi-attribute Model for Assessment of SMEs adoption of  

E-Print Network (OSTI)

Multi-attribute Model for Assessment of SMEs adoption of High Performance Computing Cloud Services boosters for SMEs, particularly manufacturing. · Huge amount of and $ are currently being spent on simulation experiments through various initiatives. #12;Introduction · Technology adoptance is in its early

Bohanec, Marko

78

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

SciTech Connect

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.

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

79

Integrated science model for assessment of climate change  

SciTech Connect

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.

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

80

Radionuclide release rates from spent fuel for performance assessment modeling  

SciTech Connect

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.

Curtis, D.B.

1994-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

Assessment of traumatic brain injury degree in animal model  

Science Journals Connector (OSTI)

AbstractObjective To establish stable and controllable brain injury with accurate degree and good repeatability in rat model. Methods Controlled cortical impact (CCI) device was used to prepare for the rat brain injury model by the impact head of different model (Group A No. 4, Group B No. 5, Group C No. 6) and the impact depth (Group A: 1.5–2.0 mm, Group B: 2.5–3.0 mm, Group C: 3.5–4.0 mm) with impact time of 0.1 s and impact velocity of 2.5 m/s. Twelve rats with three months of age were used in each group (the impact depth of every two rats was added 1 mm respectively). After modeling for 1 h, magnetic resonance imaging (MRI) was received and brain histopathology was observed to assess degree of injury by model parameters of three groups. Results After modeling of Group A, MRI showed that the cortex structure was damaged with a small amount of bleeding in center and mild edema around, and the total volume of injury was (28.69±4.94) mm3. Pathology revealed the injury was confined to the superficial cortical with mild edema of nerve cell, which was assessed as mild cerebral contusion. While after modeling, MRI of Group B showed that the structure of cortex and medulla were damaged simultaneously and extended to cerebral nuclei zone, with 4 cases of hematoma in the center and larger edema range around, and the total volume of injury was (78.38±9.28) mm3. Pathology revealed the injury range was reached nuclei zone, with swell of nerve cell and mitochondria, which was assessed to moderate cerebral contusion. After modeling of Group C, MRI showed that extensive tissue injury was appeared in cortex and medulla and deep nuclei, with 9 cases of hematoma and large edema signal of surrounding tissue T2WI, while in 5 cases, lateral nucleus of injury signal was increased, and the total volume of injury was (135.89±24.80) mm3. Pathology revealed the deep cerebral nuclei was damaged, with the disappearance of neuronal structure and vacuolization of mitochondria, which was assessed as severe cerebral contusion. MRI changes were consistent with pathological changes in three groups of model, and the injury range was significantly different (Pbrain injury model, which overcomes the randomness in previous injury model and possesses highly unity in iconography and pathology changes. This can provide quantitative modeling reference for clinical research.

Jian-Qiang Chen; Cheng-Cheng Zhang; Hong Lu; Wei Wang

2014-01-01T23:59:59.000Z

82

Enhancing Model Skill by Assimilating SMOPS Blended Soil Moisture Product into Noah Land Surface Model  

Science Journals Connector (OSTI)

Many studies that have assimilated remotely sensed soil moisture into land surface models have generally focused on retrievals from a single satellite sensor. However, few studies have evaluated the merits of assimilating ensemble product that are ...

Jifu Yin; Xiwu Zhan; Youfei Zheng; Jicheng Liu; Li Fang; Christopher R. Hain

83

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

SciTech Connect

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.

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

84

Estimation of aerial deposition and foliar uptake of xenobiotics: Assessment of current models  

SciTech Connect

This report reviews existing mathematical and/or computer simulation models that estimate xenobiotic deposition to and transport through (both curricular and stomatal) vegetative surfaces. The report evaluates the potential for coupling the best of those models to the existing Uptake, Translocation, Accumulation, and Biodegradation model to be used for future xenobiotic exposure assessments. Here xenobiotic compounds are defined as airborne contaminants, both organic and gaseous pollutants, that are introduced into the environment by man. Specifically this document provides a detailed review of the state-of-the-art models that addressed aerial deposition of particles and gases to foliage; foliar and cuticular transport, metabolism, and uptake of organic xenobiotics; and stomatal transport of gaseous and volatile organic xenobiotic pollutants. Where detailed information was available, parameters for each model are provided on a chemical by chemical as well as species by species basis. Sufficient detail is provided on each model to assess the potential for adapting or coupling the model to the existing UTAB plant exposure model. 126 refs., 6 figs., 10 tabs.

Link, S.O.; Fellows, R.J.; Cataldo, D.A.; Droppo, J.G.; Van Voris, P.

1987-10-01T23:59:59.000Z

85

E-Print Network 3.0 - assessment modeling productivity Sample...  

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

Summary: models is suggested as a means of improving the impact assessment phase of LCA. Keywords: Life Cycle... assessment methodologies 1. These early inventories would...

86

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

SciTech Connect

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

Not Available

2008-10-01T23:59:59.000Z

87

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

E-Print Network (OSTI)

-based assessments of surface downwelling solar irradiance (SSI) are more and more used in the domain of solar energy studies will be performed in order to better understand the advantage and disadvantage of each product, diffuse and direct surface irradiance for use in various domains: solar energy, biomass, agriculture

Paris-Sud XI, Université de

88

Lithospheric Thickness Modeled from Long Period Surface Wave Dispersion  

SciTech Connect

The behavior of surface waves at long periods is indicative of subcrustal velocity structure. Using recently published dispersion models, we invert surface wave group velocities for lithospheric structure, including lithospheric thickness, over much of the Eastern Hemisphere, encompassing Eurasia, Africa, and the Indian Ocean. Thicker lithosphere under Precambrian shields and platforms are clearly observed, not only under the large cratons (West Africa, Congo, Baltic, Russia, Siberia, India), but also under smaller blocks like the Tarim Basin and Yangtze craton. In contrast, it is found that remobilized Precambrian structures like the Saharan Shield and Sino-Korean Paraplatform do not have well-established lithospheric keels. The thinnest lithospheric thickness is found under oceanic and continental rifts, as well as along convergence zones. We compare our results to thermal models of continental lithosphere, lithospheric cooling models of oceanic lithosphere, lithosphere-asthenosphere boundary (LAB) estimates from S-wave receiver functions, and velocity variations of global tomography models. In addition to comparing results for the broad region, we examine in detail the regions of Central Africa, Siberia, and Tibet. While there are clear differences in the various estimates, overall the results are generally consistent. Inconsistencies between the estimates may be due to a variety of reasons including lateral and depth resolution differences and the comparison of what may be different lithospheric features.

Pasyanos, M E

2008-05-15T23:59:59.000Z

89

New Near-Infrared Surface Brightness Fluctuation Models  

E-Print Network (OSTI)

We present new theoretical models for surface brightness fluctuations in the near-infrared. We show the time evolution of near-infrared brightness fluctuation properties over large age and metallicity ranges, i.e., from 12 Myr to 16 Gyr, and from Z/Zsun=1/50 to Z/Zsun=2.5, for single age, single metallicity stellar populations. All the stellar models are followed from the zero age main sequence to the central carbon ignition for massive stars, or to the end of the thermally pulsing regime of the asymptotic giant branch phase for low and intermediate mass stars. The new models are compared with observed near-infrared fluctuation absolute magnitudes and colours for a sample of Magellanic Cloud star clusters and Fornax Cluster galaxies. For star clusters younger than ~3 Gyr, the predicted near-infrared fluctuation properties are in a satisfactory agreement with observed ones over a wide range of stellar population metallicities. However, for older star clusters, the agreement between the observed and predicted near-IR brightness fluctuations depends on how the surface brightness absolute magnitudes are estimated. The computed set of models are not able to match the observed near-IR fluctuation absolute magnitudes and colours simultaneously. We argue that the observed discrepancies between the predicted and observed properties of old MC superclusters are more likely due to observational reasons.

M. Mouhcine; R. A. Gonzalez; M. C. Liu

2005-11-30T23:59:59.000Z

90

Assessing the cleanliness of surfaces: Innovative molecular approaches vs. standard spore assays  

SciTech Connect

A bacterial spore assay and a molecular DNA microarray method were compared for their ability to assess relative cleanliness in the context of bacterial abundance and diversity on spacecraft surfaces. Colony counts derived from the NASA standard spore assay were extremely low for spacecraft surfaces. However, the PhyloChip generation 3 (G3) DNA microarray resolved the genetic signatures of a highly diverse suite of microorganisms in the very same sample set. Samples completely devoid of cultivable spores were shown to harbor the DNA of more than 100 distinct microbial phylotypes. Furthermore, samples with higher numbers of cultivable spores did not necessarily give rise to a greater microbial diversity upon analysis with the DNA microarray. The findings of this study clearly demonstrated that there is not a statistically significant correlation between the cultivable spore counts obtained from a sample and the degree of bacterial diversity present. Based on these results, it can be stated that validated state-of-the-art molecular techniques, such as DNA microarrays, can be utilized in parallel with classical culture-based methods to further describe the cleanliness of spacecraft surfaces.

Cooper, M.; Duc, M.T. La; Probst, A.; Vaishampayan, P.; Stam, C.; Benardini, J.N.; Piceno, Y.M.; Andersen, G.L.; Venkateswaran, K.

2011-04-01T23:59:59.000Z

91

Developing a Modeling Framework for Assessing Population Impacts of  

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

Developing a Modeling Framework for Assessing Population Impacts of Developing a Modeling Framework for Assessing Population Impacts of Residential Air Quality Policies Speaker(s): Jennifer Logue Date: November 13, 2012 - 12:00pm Location: 90-3122 Seminar Host/Point of Contact: Brett Singer People spend the majority of their time in residences and the health burden of indoor air is significant. However, the definitions of "acceptable" and "good" indoor air quality (IAQ), and the most effective, energy efficient methods for achieving various levels of IAQ are still matters of research and debate. Current ventilation standards focus on minimum requirements for overall and mechanically provided ventilation rates, and vented combustion equipment, and require only the installation of kitchen and bath exhaust fans for source control. These standards generally are

92

On surface temperature, greenhouse gases, and aerosols: models and observations  

SciTech Connect

The effect of changes in atmospheric carbon dioxide concentrations and sulphate aerosols on near-surface temperature is investigated using a version of the Hadley Centre atmospheric model coupled to a mixed layer ocean. The scattering of sunlight by sulphate aerosols is represented by appropriately enhancing the surface albedo. On doubling atmospheric carbon dioxide concentrations, the global mean temperature increases by 5.2 K. An integration with a 39% increase in CO{sub 2}, giving the estimated change in radiative heating due to increases in greenhouse gases since 1900, produced an equilibrium warming of 2.3 K, which, even allowing for oceanic inertia, is significantly higher than the observed warming over the same period. Furthermore, the simulation suggests a substantial warming everywhere, whereas the observations indicate isolated regions of cooling, including parts of the northern midlatitude continents. The addition of an estimate of the effect of scattering by current industrial aerosols (uncertain by a factor of at least 3) leads to improved agreement with the observed pattern of changes over the northern continents and reduces the global mean warming by about 30%. Doubling the aerosol forcing produces patterns that are still compatible with the observations, but further increase leads to unrealistically extensive cooling in the midlatitudes. The diurnal range of surface temperature decreases over most of the northern extratropics on increasing CO{sub 2}, in agreement with recent observations. The addition of the current industrial aerosol had little detectable effect on the diurnal range in the model because the direct effect of reduced solar heating at the surface is approximately balanced by the indirect effects of cooling. Thus, the ratio of the reduction in diurnal range to the mean warming is increased, in closer agreement with observations. Results from further sensitivity experiments with larger increases in aerosol and CO{sub 2} are presented.

Mitchell, J.F.B.; Davis, R.A.; Ingram, W.J.; Senior, C.A. [Hadley Centre for Climate Prediction and Research, Berkshire (United Kingdom)] [Hadley Centre for Climate Prediction and Research, Berkshire (United Kingdom)

1995-10-01T23:59:59.000Z

93

A residence-time-based transport approach for the groundwater pathway in performance assessment models  

Science Journals Connector (OSTI)

This paper presents the theoretical development and numerical implementation of a new modeling approach for representing the groundwater pathway in risk assessment or performance assessment model of a contaminant transport system. The model developed ... Keywords: Groundwater pathway, Mixing model, Performance assessment, Residence time distribution

Bruce A. Robinson; Shaoping Chu

2013-03-01T23:59:59.000Z

94

Modeling issues associated with production reactor safety assessment  

SciTech Connect

This paper describes several Probabilistic Safety Assessment (PSA) modeling issues that are related to the unique design and operation of the production reactors. The identification of initiating events and determination of a set of success criteria for the production reactors is of concern because of their unique design. The modeling of accident recovery must take into account the unique operation of these reactors. Finally, a more thorough search and evaluation of common-cause events is required to account for combinations of unique design features and operation that might otherwise not be included in the PSA. It is expected that most of these modeling issues also would be encountered when modeling some of the other more unique reactor and nonreactor facilities that are part of the DOE nuclear materials production complex. 9 refs., 2 figs.

Stack, D.W. (Los Alamos National Lab., NM (USA)); Thomas, W.R. (Science and Engineering Associates, Inc., Albuquerque, NM (USA))

1990-01-01T23:59:59.000Z

95

PORFLOW Modeling Supporting The H-Tank Farm Performance Assessment  

SciTech Connect

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.

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

2012-08-31T23:59:59.000Z

96

Replication of surface features from a master model to an amorphous metallic article  

DOE Patents (OSTI)

The surface features of an article are replicated by preparing a master model having a preselected surface feature thereon which is to be replicated, and replicating the preselected surface feature of the master model. The replication is accomplished by providing a piece of a bulk-solidifying amorphous metallic alloy, contacting the piece of the bulk-solidifying amorphous metallic alloy to the surface of the master model at an elevated replication temperature to transfer a negative copy of the preselected surface feature of the master model to the piece, and separating the piece having the negative copy of the preselected surface feature from the master model.

Johnson, William L. (Pasadena, CA); Bakke, Eric (Murrieta, CA); Peker, Atakan (Aliso Viejo, CA)

1999-01-01T23:59:59.000Z

97

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

E-Print Network (OSTI)

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

Fant, C.A.

98

NUMERICAL ANALYSIS OF A STEEPEST-DESCENT PDE MODEL FOR SURFACE RELAXATION BELOW THE ROUGHENING  

E-Print Network (OSTI)

NUMERICAL ANALYSIS OF A STEEPEST-DESCENT PDE MODEL FOR SURFACE RELAXATION BELOW THE ROUGHENING addresses a widely-used PDE model for the relaxation of a crystalline surface below the roughening

99

A Conceptual Model of the Surface Salinity Distribution in the Oceanic Hadley Cell  

Science Journals Connector (OSTI)

A conceptual model of the salinity distribution in the oceanic Hadley cell is presented. The model pertains to the region of tropical easterly surface winds, where the surface salinity increases poleward from a local salinity minimum near the ...

Johan Nilsson; Heiner Körnich

2008-12-01T23:59:59.000Z

100

Utilizing geographic information systems technology in the Wyoming cumulative hydrologic impact assessment modeling process  

SciTech Connect

The coal-permitting process places heavy demands on both permit applicants and regulatory authorities with respect to the management and analysis of hydrologic data. Currently, this correlation is being addressed for the Powder River Basin, Wyoming by the ongoing Cumulative Hydrologic Impact Assessment (CHIA) efforts at the University of Wyoming. One critical component of the CHIA is the use of a Geographic Information System (GIS) for support, management, manipulation, pre-analysis, and display of data associated with the chosen groundwater and surface water models. This paper will discuss the methodology in using of GIS technology as an integrated tool with the MODFLOW and HEC-1 hydrologic models. Pre-existing GIS links associated with these two models served as a foundation for this effort. However, due to established standards and site specific factors, substantial modifications were performed on existing tools to obtain adequate results. The groundwater-modeling effort required the use of a refined grid in which cell sizes varied based on the relative locations of ongoing mining activities. Surface water modeling was performed in a semi-arid region with very limited topographic relief and predominantly ephemeral stream channels. These were substantial issues that presented challenges for effective GIS/model integration.

Hamerlinck, J.D.; Oakleaf, J.R. [Univ. of Wyoming, Laramie, WY (United States)

1997-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

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

SciTech Connect

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.

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

102

E-Print Network 3.0 - actuator surface model Sample Search Results  

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

the mirror surface parallel... resistances, thermal coupling between the actuators, and heat loss by thermal convection 6. This model... in (4), this model considers the...

103

Methods for Developing Emissions Scenarios for Integrated Assessment Models  

SciTech Connect

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.

Prinn, Ronald [MIT; Webster, Mort [MIT

2007-08-20T23:59:59.000Z

104

Assessment of damage to the desert surfaces of Kuwait due to the Gulf War  

SciTech Connect

This is a preliminary report on a joint research project by Boston University and the Kuwait Institute for Scientific Research that commenced in April 1992. The project aim is to establish the extent and nature of environmental damage to the desert surface and coastal zone of Kuwait due to the Gulf War and its aftermath. Change detection image enhancement techniques were employed to enhance environmental change by comparison of Landsat Thematic Mapper images obtained before the wars and after the cessation of the oil and well fires. Higher resolution SPOT images were also utilized to evaluate the nature of the environmental damage to specific areas. The most prominent changes were due to: (1) the deposition of oil and course-grained soot on the desert surface as a result of oil rain'' from the plume that emanated from the oil well fires; (2) the formation of hundreds of oil lakes, from oil seepage at the damaged oil well heads; (3) the mobilization of sand and dust and (4) the pollution of segments of the coastal zone by the deposition of oil from several oil spills. Interpretation of satellite image data are checked in the field to confirm the observations, and to assess the nature of the damage. Final results will be utilized in establishing the needs for remedial action to counteract the harmful effects of the various types of damage to the environment of Kuwait.

El-Baz, F. (Boston Univ., MA (United States). Center for Remote Sensing); Al-Ajmi, D. (Kuwait Inst. for Scientific Research (Kuwait). Environmental and Earth Sciences Div.)

1993-01-01T23:59:59.000Z

105

Surface water drainage system. Environmental assessment and finding of no significant impact  

SciTech Connect

This Environmental Assessment (EA) is written pursuant to the National Environmental Policy Act (NEPA). The document identifies and evaluates the action proposed to correct deficiencies in, and then to maintain, the surface water drainage system serving the Department of Energy`s Rocky Flats Environmental Technology Site (Site), located north of Golden, Colorado. Many of the activities proposed would not normally be subject to this level of NEPA documentation. However, in many cases, maintenance of the system has been deferred to the point that wetlands vegetation has become established in some ditches and culverts, creating wetlands. The proposed activities would damage or remove some of these wetlands in order to return the drainage system to the point that it would be able to fully serve its intended function - stormwater control. The Department of Energy (DOE) regulations require that activities affecting environmentally sensitive areas like wetlands be the subject of an EA. Most portions of the surface water drainage system are presently inadequate to convey the runoff from a 100-year storm event. As a result, such an event would cause flooding across much of the Site and possibly threaten the integrity of the dams at the terminal ponds. Severe flooding would not only cause damage to facilities and equipment, but could also facilitate the transport of contaminants from individual hazardous substance sites (IHSSs). Uncontrolled flow through the A- and B-series ponds could cause contaminated sediments to become suspended and carried downstream. Additionally, high velocity flood flows significantly increase erosion losses.

NONE

1996-05-01T23:59:59.000Z

106

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

SciTech Connect

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

Curtis, Michael M.

2007-07-31T23:59:59.000Z

107

Test Plan to Assess Fire Effects on the Function of an Engineered Surface Barrier  

SciTech Connect

Wildfire is a frequent perturbation in shrub steppe ecosystems, altering the flora, fauna, atmosphere, and soil of these systems. Research on the fire effects has focused mostly on natural ecosystems with essentially no attention on engineered systems like surface barriers. The scope of the project is to use a simulated wildfire to induce changes in an engineered surface barrier and document the effects on barrier performance. The main objective is to quantify the effects of burning and the resulting post-fire conditions on alterations in soil physical properties; hydrologic response, particularly the water balance; geochemical properties; and biological properties. A secondary objective is to use the lessons learned to maximize fire protection in the design of long-term monitoring systems based on electronic sensors. A simulated wildfire will be initiated, controlled and monitored at the 200-BP-1 barrier in collaboration with the Hanford Fire Department during the fall of 2008. The north half of the barrier will be divided into nine 12 x 12 m plots, each of which will be randomly assigned a fuel load of 2 kg m-2 or 4 kg m-2. Each plot will be ignited around the perimeter and flames allowed to carry to the centre. Any remaining unburned vegetation will be manually burned off using a drip torch. Progress of the fire and its effects will be monitored using point measurements of thermal, hydrologic, and biotic variables. Three measures of fire intensity will be used to characterize fire behavior: (1) flame height, (2) the maximum temperature at three vertical profile levels, and (3) total duration of elevated temperature at these levels. Pre-burn plant information, including species diversity, plant height, and canopy diameter will be measured on shrubs from the plots to be burned and from control plots at the McGee ranch. General assessments of shrub survival, recovery, and recruitment will be made after the fire. Near-surface soil samples will be collected pre- and post-burn to determine changes in the gravel content of the surface layer so as to quantify inflationary or deflationary responses to fire and to reveal the ability of the surface to resist post-fire erosive stresses. Measures of bulk density, water repellency, water retention, and hydraulic conductivity will be used to characterize changes in infiltration rates and water storage capacity following the fire. Samples will also be analyzed to quantify geochemical changes including changes in soil pH, cation exchange capacity, specific surface area, and the concentration of macro nutrients (e.g. N, P, K) and other elements such as Na, Mg, Ca, that are critical to the post-fire recovery revegetation. Soil CO2 emissions will be measured monthly for one year following the burn to document post-fire stimulation of carbon turnover and soil biogenic emissions. Surface and subsurface temperature measurements at and near monitoring installations will be used to document fire effects on electronic equipment. The results of this study will be used to bridge the gaps in knowledge on the effects of fire on engineered ecosystems (e.g. surface barriers), particularly the hydrologic and biotic characteristics that govern the water and energy balance. These results will also support the development of practical fire management techniques for barriers that are compatible with wildfire suppression strategies. Furthermore, lessons learned will be use to develop installation strategies needed to protect electronic monitoring equipment from the intense heat of fire and the potential damaging effects of smoke and fire extinguishing agents. Such information is needed to better understand long-term barrier performance under extreme conditions, especially if site maintenance and operational funding is lost for activities such as barrier revegetation.

Ward, Anderson L.; Berlin, Gregory T.; Cammann, Jerry W.; Leary, Kevin D.; Link, Steven O.

2008-09-29T23:59:59.000Z

108

Modeling Exposure to Persistent Chemicals in Hazard and Risk Assessment  

SciTech Connect

Fate and exposure modeling has not thus far been explicitly used in the risk profile documents prepared to evaluate significant adverse effect of candidate chemicals for either the Stockholm Convention or the Convention on Long-Range Transboundary Air Pollution. However, we believe models have considerable potential to improve the risk profiles. Fate and exposure models are already used routinely in other similar regulatory applications to inform decisions, and they have been instrumental in building our current understanding of the fate of POP and PBT chemicals in the environment. The goal of this paper is to motivate the use of fate and exposure models in preparing risk profiles in the POP assessment procedure by providing strategies for incorporating and using models. The ways that fate and exposure models can be used to improve and inform the development of risk profiles include: (1) Benchmarking the ratio of exposure and emissions of candidate chemicals to the same ratio for known POPs, thereby opening the possibility of combining this ratio with the relative emissions and relative toxicity to arrive at a measure of relative risk. (2) Directly estimating the exposure of the environment, biota and humans to provide information to complement measurements, or where measurements are not available or are limited. (3) To identify the key processes and chemical and/or environmental parameters that determine the exposure; thereby allowing the effective prioritization of research or measurements to improve the risk profile. (4) Predicting future time trends including how quickly exposure levels in remote areas would respond to reductions in emissions. Currently there is no standardized consensus model for use in the risk profile context. Therefore, to choose the appropriate model the risk profile developer must evaluate how appropriate an existing model is for a specific setting and whether the assumptions and input data are relevant in the context of the application. It is possible to have confidence in the predictions of many of the existing models because of their fundamental physical and chemical mechanistic underpinnings and the extensive work already done to compare model predictions and empirical observations. The working group recommends that modeling tools be applied for benchmarking PBT/POPs according to exposure-to-emissions relationships, and that modeling tools be used to interpret emissions and monitoring data. The further development of models that couple fate, long-range transport, and bioaccumulation should be fostered, especially models that will allow time trends to be scientifically addressed in the risk profile.

Cowan-Ellsberry, Christina E.; McLachlan, Michael S.; Arnot, Jon A.; MacLeod, Matthew; McKone, Thomas E.; Wania, Frank

2008-11-01T23:59:59.000Z

109

Examining emissions policy issues with an integrated assessment model  

SciTech Connect

In the policy analysis process of asking ``What if'' questions, there is considerable advantage in the analyst being able to address the questions directly rather than sending the questions to scientists in particular disciplines and awaiting answers. Obviously the former option is likely to produce speedier results than the latter; in addition, the questions can be easily modified as the issues change or become more focused. The primary potential shortcoming of an analyst addressing questions that may be beyond his or her particular expertise is that the policy analyst may not understand the limitations of the analysis. Here the author briefly describes a peer-reviewed integrated assessment model that can be exercised within minutes in a desktop environment, discuss some of the advantages and limitations of the approach, and exercise portions of the model to compare with observations. Because of the nature of the conference at which this paper is being presented, the discussion focuses on the air pollution modeling components of the integrated assessment.

Shannon, J. D.

1999-10-21T23:59:59.000Z

110

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

SciTech Connect

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.

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

2013-06-13T23:59:59.000Z

111

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

SciTech Connect

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.

Niyogi, Devdutta S. [Purdue

2013-06-07T23:59:59.000Z

112

Facet Model and Mathematical Morphology for Surface Characterization  

SciTech Connect

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.

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

1999-11-13T23:59:59.000Z

113

A preliminary study to Assess Model Uncertainties in Fluid Flows  

SciTech Connect

The goal of this study is to assess the impact of various flow models for a simplified primary coolant loop of a light water nuclear reactor. The various fluid flow models are based on the Euler equations with an additional friction term, gravity term, momentum source, and energy source. The geometric model is purposefully chosen simple and consists of a one-dimensional (1D) loop system in order to focus the study on the validity of various fluid flow approximations. The 1D loop system is represented by a rectangle; the fluid is heated up along one of the vertical legs and cooled down along the opposite leg. A pressurizer and a pump are included in the horizontal legs. The amount of energy transferred and removed from the system is equal in absolute value along the two vertical legs. The various fluid flow approximations are compressible vs. incompressible, and complete momentum equation vs. Darcy’s approximation. The ultimate goal is to compute the fluid flow models’ uncertainties and, if possible, to generate validity ranges for these models when applied to reactor analysis. We also limit this study to single phase flows with low-Mach numbers. As a result, sound waves carry a very small amount of energy in this particular case. A standard finite volume method is used for the spatial discretization of the system.

Marc Oliver Delchini; Jean C. Ragusa

2009-09-01T23:59:59.000Z

114

Review of free-surface MHD experiments and modeling.  

SciTech Connect

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.

Molokov, S.; Reed, C. B.

2000-06-02T23:59:59.000Z

115

Surface deacidification of ZSM5 by SiCl4 treatment: Assessment of surface specificity by methylene blue adsorption  

Science Journals Connector (OSTI)

A study has been made of ZSM5 zeolite deacidification (dealumination) by high temperature treatment in SiCl4 vapour, monitoring total acidity by Na+-exchange, and external surface acidity by methylene blue adsorp...

J. R. Anderson; Y. -F. Chang; A. E. Hughes

1989-01-01T23:59:59.000Z

116

THE PENA BLANCA NATURAL ANALOGUE PERFORMANCE ASSESSMENT MODEL  

SciTech Connect

The Nopal I uranium mine in the Sierra Pena Blanca, Chihuahua, Mexico serves as a natural analogue to the Yucca Mountain repository. The Pena Blanca Natural Analogue Performance Assessment Model simulates the mobilization and transport of radionuclides that are released from the mine and transported to the saturated zone. The Pena Blanca Natural Analogue Performance Assessment Model uses probabilistic simulations of hydrogeologic processes that are analogous to the processes that occur at the Yucca Mountain site. The Nopal I uranium deposit lies in fractured, welded, and altered rhyolitic ash-flow tuffs that overlie carbonate rocks, a setting analogous to the geologic formations at the Yucca Mountain site. The Nopal I mine site has the following analogous characteristics as compared to the Yucca Mountain repository site: (1) Analogous source--UO{sub 2} uranium ore deposit = spent nuclear fuel in the repository; (2) Analogous geology--(i.e. fractured, welded, and altered rhyolitic ash-flow tuffs); (3) Analogous climate--Semiarid to arid; (4) Analogous setting--Volcanic tuffs overlie carbonate rocks; and (5) Analogous geochemistry--Oxidizing conditions Analogous hydrogeology: The ore deposit lies in the unsaturated zone above the water table.

G. Saulnier and W. Statham

2006-04-16T23:59:59.000Z

117

Simultaneous multi-band detection of Low Surface Brightness galaxies with Markovian modelling  

E-Print Network (OSTI)

We present an algorithm for the detection of Low Surface Brightness (LSB) galaxies in images, called MARSIAA (MARkovian Software for Image Analysis in Astronomy), which is based on multi-scale Markovian modeling. MARSIAA can be applied simultaneously to different bands. It segments an image into a user-defined number of classes, according to their surface brightness and surroundings - typically, one or two classes contain the LSB structures. We have developed an algorithm, called DetectLSB, which allows the efficient identification of LSB galaxies from among the candidate sources selected by MARSIAA. To assess the robustness of our method, the method was applied to a set of 18 B and I band images (covering 1.3 square degrees in total) of the Virgo cluster. To further assess the completeness of the results of our method, both MARSIAA, SExtractor, and DetectLSB were applied to search for (i) mock Virgo LSB galaxies inserted into a set of deep Next Generation Virgo Survey (NGVS) gri-band subimages and (ii) Virgo...

Vollmer, B; Petremand, M; Lavigne, F; Collet, Ch; van Driel, W; Bonnarel, F; Louys, M; Sabatini, S; MacArthur, L A

2012-01-01T23:59:59.000Z

118

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

SciTech Connect

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.

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

2008-07-01T23:59:59.000Z

119

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

E-Print Network (OSTI)

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

Fischlin, Andreas

120

Water Research 38 (2004) 33313339 Testing a surface tension-based model to predict the salting  

E-Print Network (OSTI)

Water Research 38 (2004) 3331­3339 Testing a surface tension-based model to predict the salting out associated with transferring solutes from water to a salt solution to the difference in surface tensions likely reflects the inability of the simple surface tension model to account for all interactions among

Herbert, Bruce

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

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

122

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

E-Print Network (OSTI)

reason why nickel-base superalloys, which are often used in the most critical gas-turbine engine applications, including gas-turbine engines. Modern aircraft turbine engine components are designed using Assessment of Near-Surface Residual Stress in Shot-Peened Nickel-Base Superalloys Mark P. Blodgett1 and Peter

Nagy, Peter B.

123

Assessing the flammability of surface fuels beneath ornamental vegetation in wildland urban interfaces in Provence (south-eastern France)  

E-Print Network (OSTI)

characteristics according to the composition of their litter. Hierarchical cluster analysis ranked the sevenAssessing the flammability of surface fuels beneath ornamental vegetation in wildland� urbanA A Irstea UR EMAX, 3275 route de C�zanne, CS 40061, F-13182 Aix-en-Provence, cedex 5, France. B

Boyer, Edmond

124

An integrated environmental modeling framework for performing Quantitative Microbial Risk Assessments  

Science Journals Connector (OSTI)

Standardized methods are often used to assess the likelihood of a human-health effect from exposure to a specified hazard, and inform opinions and decisions about risk management and communication. A Quantitative Microbial Risk Assessment (QMRA) is specifically ... Keywords: Integrated environmental modeling, Manure, Pathogens, QMRA, Risk assessment, Watershed modeling

Gene Whelan, Keewook Kim, Mitch A. Pelton, Jeffrey A. Soller, Karl J. Castleton, Marirosa Molina, Yakov Pachepsky, Richard Zepp

2014-05-01T23:59:59.000Z

125

Models for source term, flow, transport and dose assessment in NRC`s Iterative Performance Assessment, Phase 2  

SciTech Connect

The core consequence modules for the recently completed Phase 2 Iterative Performance Assessment (IPA) of the Yucca Mountain repository for high-level nuclear waste depend on models for releases from the engineered barrier system (source term), flow of liquid and gas, transport of radionuclides in the geosphere and assessment of dose to target populations. The source term model includes temperature and moisture phenomena in the near-field environment, general, pitting and crevice corrosion, contact of the waste form by water, dissolution and oxidation of the waste form, and transport of dissolved and gaseous radionuclides from the waste package by advection and diffusion. The liquid flow and transport models describe water flow through fractures and matrix in both the unsaturated and saturated zones. Models for flow of gas and transport of {sup 14}CO{sub 2} released from the engineered barrier system to the atmosphere take into account repository heat and the geothermal gradient. The dose assessment model calculates doses to a regional population and a farm family for an assumed reference biosphere in the vicinity of the repository. The Phase 2 IPA led to a number of suggestions for model improvement: (1) improve the ability of the models to include spatial and temporal variability in the parameters; (2) improve the coupling among processes, especially the effects of changing environments in the waste packages; (3) develop more mechanistic models, but abstracted for use in total system performance assessment; and (4) use more site specific parameters, especially for the dose assessments.

McCartin, T.; Codell, R.; Neel, R.; Ford, W.; Wescott, R.; Bradbury, J. [Nuclear Regulatory Commission, Washington, DC (United States); Sagar, B.; Walton, J. [Center for Nuclear Waste Regulatory Analyses, San Antonio, TX (United States)

1994-12-31T23:59:59.000Z

126

Measurement of Surface Energy Fluxes from Two Rangeland Sites and Comparison with a Multilayer Canopy Model  

Science Journals Connector (OSTI)

Rangelands are often characterized by a patchy mosaic of vegetation types, making measurement and modeling of surface energy fluxes particularly challenging. The purpose of this study was to evaluate surface energy fluxes measured using three eddy ...

Gerald N. Flerchinger; Michele L. Reba; Danny Marks

2012-06-01T23:59:59.000Z

127

Transportation System Risk Assessment (TSRA) bounding release model  

SciTech Connect

Transportation System Risk Assessments (TSRAs) document the compliance of proposed shipments of nuclear components with applicable federal regulations as well as the associated risks involved. If a relatively simple bounding analysis can show that the consequences resulting from a worst case scenario are acceptably low, a more time intensive and costly risk analysis can be avoided. Therefore, a bounding release FORTRAN model has been developed to determine the consequences of a worst case non-criticality transportation accident. The consequences of three conservative bounding accidents are determined by the model: (1) direct radiation exposure, (2) airborne release of radiological and/or hazardous solid material, and (3) release of radiological and/or hazardous solid material into a waterway and subsequent uptake by an individual through drinking water. Program output includes the direct radiation exposure (mrem), maximum downwind concentration (mg/m{sup 3}), radiation dose (mrem) received as a result of the postulated airborne release of radiological material, intake (mg) due to inhalation, radiation dose (mrem) received by an individual resulting from a release of radiological material into a waterway and uptake into drinking water, and uptake (mg) due to ingestion. This report documents the methodologies and correlations used in the numerical model to perform the bounding consequence calculations.

Anderson, J.C.

1997-10-01T23:59:59.000Z

128

Predictive Model for Environmental Assessment in Additive Manufacturing Process  

Science Journals Connector (OSTI)

Abstract Additive Manufacturing is an innovative way to produce parts. However its environmental impact is unknown. To ensure the development of additive manufacturing processes it seems important to develop the concept of DFSAM (Design for Sustainable Additive Manufacturing). In fact, one of the objectives of environmental sustainable manufacturing is to minimize the whole flux consumption (electricity, material and fluids) during manufacturing step. To achieve this goal, it is interesting to get a predictive model of consumptions, integrated in the design step, allowing to evaluate the product's environmental impact during the manufacturing step. This paper presents a new methodology for electric, fluids and raw material consumptions assessment for additive manufacturing processes, in particular for a direct metal deposition process. The methodology will help engineers to design parts optimized for additive manufacturing with an environmental point of view.

Florent Le Bourhis; Olivier Kerbrat; Lucas Dembinski; Jean-Yves Hascoet; Pascal Mognol

2014-01-01T23:59:59.000Z

129

A simulation model of focus and radial servos in Compact Disc players with Disc surface defects  

E-Print Network (OSTI)

A simulation model of focus and radial servos in Compact Disc players with Disc surface defects P of controllers handling surface defects easier. A simulation model of Compact Disc players playing discs of the controller has been based on trial and error on real test systems since no simulation models of the defects

Wickerhauser, M. Victor

130

Surface Tension Adjustment in a Pseudo-Potential Lattice Boltzmann Model  

E-Print Network (OSTI)

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.

Hu, Anjie; Uddin, Rizwan

2014-01-01T23:59:59.000Z

131

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

SciTech Connect

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.

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

132

Simultaneous Multi-band Detection of Low Surface Brightness Galaxies with Markovian Modeling  

Science Journals Connector (OSTI)

We present to the astronomical community an algorithm for the detection of low surface brightness (LSB) galaxies in images, called MARSIAA (MARkovian Software for Image Analysis in Astronomy), which is based on multi-scale Markovian modeling. MARSIAA can be applied simultaneously to different bands. It segments an image into a user-defined number of classes, according to their surface brightness and surroundings—typically, one or two classes contain the LSB structures. We have developed an algorithm, called DetectLSB, which allows the efficient identification of LSB galaxies from among the candidate sources selected by MARSIAA. The application of the method to two and three bands simultaneously was tested on simulated images. Based on our tests, we are confident that we can detect LSB galaxies down to a central surface brightness level of only 1.5 times the standard deviation from the mean pixel value in the image background. To assess the robustness of our method, the method was applied to a set of 18 B- and I-band images (covering 1.3 deg2 in total) of the Virgo Cluster to which Sabatini et al. previously applied a matched-filter dwarf LSB galaxy search algorithm. We have detected all 20 objects from the Sabatini et al. catalog which we could classify by eye as bona fide LSB galaxies. Our method has also detected four additional Virgo Cluster LSB galaxy candidates undetected by Sabatini et al. To further assess the completeness of the results of our method, both MARSIAA, SExtractor, and DetectLSB were applied to search for (1) mock Virgo LSB galaxies inserted into a set of deep Next Generation Virgo Survey (NGVS) gri-band subimages and (2) Virgo LSB galaxies identified by eye in a full set of NGVS square degree gri images. MARSIAA/DetectLSB recovered ~20% more mock LSB galaxies and ~40% more LSB galaxies identified by eye than SExtractor/DetectLSB. With a 90% fraction of false positives from an entirely unsupervised pipeline, a completeness of 90% is reached for sources with r e > 3'' at a mean surface brightness level of ?g = 27.7 mag arcsec–2 and a central surface brightness of ?0 g = 26.7 mag arcsec–2. About 10% of the false positives are artifacts, the rest being background galaxies. We have found our proposed Markovian LSB galaxy detection method to be complementary to the application of matched filters and an optimized use of SExtractor, and to have the following advantages: it is scale free, can be applied simultaneously to several bands, and is well adapted for crowded regions on the sky.

B. Vollmer; B. Perret; M. Petremand; F. Lavigne; Ch. Collet; W. van Driel; F. Bonnarel; M. Louys; S. Sabatini; L. A. MacArthur

2013-01-01T23:59:59.000Z

133

Vacancy-Buckling Model for the (2×2) GaAs(111) Surface  

Science Journals Connector (OSTI)

A vacancy-buckling model is proposed for the (2×2) structure of the GaAs(111) surface. The model is confirmed by analysis of low-energy electron diffraction spectra. A reconstruction mechanism, basic to III-V compound surfaces, is proposed which favors equal numbers of dangling bonds on the nearest Ga and As neighbors. This model explains the (2×2) and (1×1) periodicities observed on (111) and (110) surfaces, respectively.

S. Y. Tong; G. Xu; W. N. Mei

1984-05-07T23:59:59.000Z

134

Surface tension model for surfactant solutions at the critical micelle concentration  

E-Print Network (OSTI)

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.

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

135

Canonical surfaces associated with projectors in Grassmannian sigma models  

SciTech Connect

We discuss the construction of higher-dimensional surfaces based on the harmonic maps of S{sup 2} into CP{sup N-1} and other Grassmannians. We show that there are two ways of implementing this procedure - both based on the use of the relevant projectors. We study various properties of such projectors and show that the Gaussian curvature of these surfaces, in general, is not constant. We look in detail at the surfaces corresponding to the Veronese sequence of such maps and show that for all of them this curvature is constant but its value depends on which mapping is used in the construction of the surface.

Hussin, V. [Centre de Recherches Mathematiques, Universite de Montreal, C.P. 6128, Succ. Centre-ville, Montreal, Quebec H3C 3J7 (Canada); Departement de Mathematiques et de Statistique, Universite de Montreal, C.P. 6128, Succ. Centre-ville, Montreal, Quebec H3C 3J7 (Canada); Yurdusen, I. [Centre de Recherches Mathematiques, Universite de Montreal, C.P. 6128, Succ. Centre-ville, Montreal, Quebec H3C 3J7 (Canada); Zakrzewski, W. J. [Department of Mathematical Sciences, University of Durham, Durham DH1 3LE (United Kingdom)

2010-10-15T23:59:59.000Z

136

Surface-Roughened Light-Emitting Diodes: An Accurate Model  

Science Journals Connector (OSTI)

Surface roughening is frequently employed to increase light extraction from light-emitting diodes (LEDs), especially in the important case of III-Nitride LEDs. We ...

David, Aurelien

2013-01-01T23:59:59.000Z

137

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

E-Print Network (OSTI)

1 Ventilation performance prediction for buildings: Model Assessment Qingyan Chena,b,* , Kisup Leeb building, but cannot provide detailed flow information in a room. The zonal model can be useful when a user ventilation systems for buildings requires a suitable model to assess system performance. The performance can

Chen, Qingyan "Yan"

138

Safety Assessment for a Surface Repository in the Chernobyl Exclusion Zone - Methodology for Assessing Disposal under Intervention Conditions - 13476  

SciTech Connect

The Radioactive Waste Disposal Facility (RWDF) Buryakovka was constructed in 1986 as part of the intervention measures after the accident at Chernobyl NPP (ChNPP). Today, RWDF Buryakovka is still being operated but its maximum capacity is nearly reached. Plans for enlargement of the facility exist since more than 10 years but have not been implemented yet. In the framework of an European Commission Project DBE Technology GmbH prepared a safety analysis report of the facility in its current state (SAR) and a preliminary safety analysis report (PSAR) based on the planned enlargement. Due to its history RWDF Buryakovka does not fully comply with today's best international practices and the latest Ukrainian regulations in this area. The most critical aspects are its inventory of long-lived radionuclides, and the non-existent multi-barrier waste confinement system. A significant part of the project was dedicated, therefore, to the development of a methodology for the safety assessment taking into consideration the facility's special situation and to reach an agreement with all stakeholders involved in the later review and approval procedure of the safety analysis reports. Main aspect of the agreed methodology was to analyze the safety, not strictly based on regulatory requirements but on the assessment of the actual situation of the facility including its location within the Exclusion Zone. For both safety analysis reports, SAR and PSAR, the assessment of the long-term safety led to results that were either within regulatory limits or within the limits allowing for a specific situational evaluation by the regulator. (authors)

Haverkamp, B.; Krone, J. [DBE TECHNOLOGY GmbH, Eschenstr. 55, D-31224 Peine (Germany)] [DBE TECHNOLOGY GmbH, Eschenstr. 55, D-31224 Peine (Germany); Shybetskyi, I. [Radioenvironmental Centre at Presidium of National Academy of Sciences of Ukraine, Ul. O. Gonchara 55 b, 01054 Kiev (Ukraine)] [Radioenvironmental Centre at Presidium of National Academy of Sciences of Ukraine, Ul. O. Gonchara 55 b, 01054 Kiev (Ukraine)

2013-07-01T23:59:59.000Z

139

A surface plasmon model for laser ablation of Ag+ Ions from a roughened Ag surface  

Science Journals Connector (OSTI)

Experimental work by Shea and Compton1 suggests that Ag+ ions emitted from a roughened Ag surface irradiated by a nanosecond or...+ ion which also undergoes a small-impact parameter collision with another ion or ...

R. H. Ritchie; J. R. Manson; P. M. Echenique

1991-01-01T23:59:59.000Z

140

A continuous surface tension force formulation for diffuse-interface models  

E-Print Network (OSTI)

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

Frey, Pascal

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

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

E-Print Network (OSTI)

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

Paris-Sud XI, Université de

142

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

E-Print Network (OSTI)

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 d...

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

2014-01-01T23:59:59.000Z

143

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

E-Print Network (OSTI)

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.

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

2014-08-21T23:59:59.000Z

144

The Operational Eta Model Precipitation and Surface Hydrologic Cycle of the Columbia and Colorado Basins  

Science Journals Connector (OSTI)

The surface hydrology of the United States’ western basins is investigated using the National Centers for Environmental Prediction operational Eta Model forecasts. During recent years the model has been subject to changes and upgrades that ...

Yan Luo; Ernesto H. Berbery; Kenneth E. Mitchell

2005-08-01T23:59:59.000Z

145

A Simple Analytical Model for Understanding the Formation of Sea Surface Temperature Patterns under Global Warming  

Science Journals Connector (OSTI)

How sea surface temperature (SST) changes under global warming is critical for future climate projection because SST change affects atmospheric circulation and rainfall. Robust features derived from 17 models of phase 5 of the Coupled Model ...

Lei Zhang; Tim Li

2014-11-01T23:59:59.000Z

146

THE PENA BLANCA NATURAL ANALOGUE PERFORMANCE ASSESSMENT MODEL  

SciTech Connect

The Nopal I uranium mine in the Sierra Pena Blanca, Chihuahua, Mexico serves as a natural analogue to the Yucca Mountain repository. The Pena Blanca Natural Analogue Performance Assessment Model simulates the mobilization and transport of radionuclides that are released from the mine and transported to the saturated zone. the Pena Blanca Natural Analogue Model uses probabilistic simulations of hydrogeologic processes that are analogous to the processes that occur at the Yucca Mountain site. The Nopal I uranium deposit lies in fractured, welded, and altered rhyolitic ash flow tuffs that overlie carbonate rocks, a setting analogous to the geologic formations at the Yucca Mountain site. The Nopal I mine site has the following characteristics as compared to the Yucca Mountain repository site. (1) Analogous source: UO{sub 2} uranium ore deposit = spent nuclear fuel in the repository; (2) Analogous geologic setting: fractured, welded, and altered rhyolitic ash flow tuffs overlying carbonate rocks; (3) Analogous climate: Semiarid to arid; (4) Analogous geochemistry: Oxidizing conditions; and (5) Analogous hydrogeology: The ore deposit lies in the unsaturated zone above the water table. The Nopal I deposit is approximately 8 {+-} 0.5 million years old and has been exposed to oxidizing conditions during the last 3.2 to 3.4 million years. The Pena Blanca Natural Analogue Model considers that the uranium oxide and uranium silicates in the ore deposit were originally analogous to uranium-oxide spent nuclear fuel. The Pena Blanca site has been characterized using field and laboratory investigations of its fault and fracture distribution, mineralogy, fracture fillings, seepage into the mine adits, regional hydrology, and mineralization that shows the extent of radionuclide migration. Three boreholes were drilled at the Nopal I mine site in 2003 and these boreholes have provided samples for lithologic characterization, water-level measurements, and water samples for laboratory analysis of the saturated zone water chemistry. The results of the field investigations and laboratory analyses of rock and water samples collected at Nopal I are used to calibrate the Pena Blanca Natural Analogue Model.

G.J. Saulnier Jr; W. Statham

2006-03-10T23:59:59.000Z

147

Two-bath model for activated surface diffusion of interacting adsorbates  

E-Print Network (OSTI)

The diffusion and low vibrational motions of adsorbates on surfaces can be well described by a purely stochastic model, the so-called interacting single adsorbate model, for low-moderate coverages (\\theta \\lesssim 0.12). Within this model, the effects of thermal surface phonons and adsorbate-adsorbate collisions are accounted for by two uncorrelated noise functions which arise in a natural way from a two-bath model based on a generalization of the one-bath Caldeira-Leggett Hamiltonian. As an illustration, the model is applied to the diffusion of Na atoms on a Cu(001) surface with different coverages.

R. Martinez-Casado; A. S. Sanz; G. Rojas-Lorenzo; S. Miret-Artes

2008-10-10T23:59:59.000Z

148

IN SEARCH OF A PROBABILISTIC MODEL OF PETROLEUM RESOURCE ASSESSMENT  

Science Journals Connector (OSTI)

Publisher Summary This chapter discusses a probabilistic model of petroleum resource assessment. At present, petroleum provides the major driving energy for national economies. The foreseen worldwide depletion of petroleum resources in a few decades, at a time of transition to new energy technologies, imposes hardships on many nations but enhances opportunities for those having a petroleum potential. The petroleum prospective areas of the world consist of sedimentary basins and geosynclines not too intensely deformed tectonically, including the continental shelves down to 200 m depth, with a total area under national jurisdictions of about 26.1 million sq mi. Certain oceanic areas beyond the continental shelves—continental rise and continental slope—have petroleum prospects, but their eventual development may be some 10 to 20 years away. The traditional geologic environment for petroleum has been the geosynclinal belt. The larger the tract of undrilled prospective area, the greater is the chances that thick sedimentary pods may occur here and there. Even when a few scattered pieces of evidence may indicate a thin sedimentary cover, prospects for generation and primary migration of petroleum may be enhanced by the large size of a prospective area. The examination of the distribution of petroleum occurrences throughout the world in basins with a significant amount of exploratory drilling indicates that roughly one-half of the prospective basins and geosynclines do not yield any or much petroleum.

B.F. Grossling

1979-01-01T23:59:59.000Z

149

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

E-Print Network (OSTI)

, 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

Ulm, Universität

150

Surface Finish Modeling in Micromilling of Biocompatible Materials  

E-Print Network (OSTI)

, and electronic devices tend to decrease in size. Along with the strong demand for miniaturization, new cutting-edge micromanufacturing techniques are developing in order to produce microcomponents with a smooth surface finish and high dimensional accuracy...

Berestovskyi, Dmytro V

2013-06-05T23:59:59.000Z

151

Dynamic behavior of the monomermonomer surface reaction model with adsorbate interactions  

E-Print Network (OSTI)

Dynamic behavior of the monomer­monomer surface reaction model with adsorbate interactions model with an adsorbate interaction term is studied. An epidemic analysis of the poisoning times (tp between the concentration of molecules adsorbed on the surface and the rate of adsorp- tion

Voigt, Chris

152

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

SciTech Connect

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).

Dr. Atul Jain

2005-04-17T23:59:59.000Z

153

Modeling Exposure to Persistent Chemicals in Hazard and Risk Assessment  

E-Print Network (OSTI)

of organohalogen contaminants (dioxins, PCB, PBDE andInvestigation into levels of dioxins, furans, PCBs and PBDEsfor risk assessment of dioxin-contaminated sites. Ambio 36:

Cowan-Ellsberry, Christina E.

2010-01-01T23:59:59.000Z

154

Spatio-Temporal Modelling of Near-Surface Ocean Winds  

E-Print Network (OSTI)

Introduction Motivation Data Part I: Dynamical Model State-Space Model Kalman Filter Assimilation Algorithm contour map from the Wave Assimilation Model overlaid with satellite mea- surements. #12;Forecasts Overlaid With Satellite Measurements General wave height contour map from the Wave Assimilation Model

Malmberg, Anders

155

Ensemble operational air quality assessments in Europe Improving modeling platforms with statistical analysis  

E-Print Network (OSTI)

Ensemble operational air quality assessments in Europe ­ Improving modeling platforms. For regional air quality, seven regional modeling teams combine state-of-the-art atmospheric modeling the ensemble or a unique model. Keywords: Air quality, modeling system, ensemble approach, validation

Paris-Sud XI, Université de

156

Assessment of Modes of Interannual Variability of Southern Hemisphere Atmospheric Circulation in CMIP5 Models  

Science Journals Connector (OSTI)

An assessment is made of the modes of interannual variability in the seasonal mean summer and winter Southern Hemisphere (SH) 500-hPa geopotential height in the twentieth century in models from the Coupled Model Intercomparison Project (CMIP) ...

Simon Grainger; Carsten S. Frederiksen; Xiaogu Zheng

2014-11-01T23:59:59.000Z

157

Skill assessment of three earth system models with common marine biogeochemistry  

Science Journals Connector (OSTI)

We have assessed the ability of a common ocean biogeochemical model, PISCES, to match relevant modern data fields across a range of ocean circulation fields from three distinct Earth system models: IPSL-CM4-LOOP,...

Roland Séférian; Laurent Bopp; Marion Gehlen; James C. Orr…

2013-05-01T23:59:59.000Z

158

Assessing the effects of anthropogenic aerosols on Pacific storm track using a multiscale global climate model  

Science Journals Connector (OSTI)

...Sciences Enhancing the Capability of Computational Earth System Models and Using NASA Data for Operation and Assessment...Science, Decadal and Regional Climate Prediction using Earth System Models program (M.W. and S.J.G.). PNNL is operated...

Yuan Wang; Minghuai Wang; Renyi Zhang; Steven J. Ghan; Yun Lin; Jiaxi Hu; Bowen Pan; Misti Levy; Jonathan H. Jiang; Mario J. Molina

2014-01-01T23:59:59.000Z

159

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

E-Print Network (OSTI)

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

Bak, Claus Leth

160

A phenomenological muscle model to assess history dependent effects in human movement  

E-Print Network (OSTI)

A phenomenological muscle model to assess history dependent effects in human movement C.P. Mc of the history dependent effects. The phenomenological model of stretch-induced force enhancement was dependent

Ben-Yakar, Adela

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Assessing the Potential of Using Traffic Simulation Model Results for Evaluating Automatic Incident Detection Algorithms  

E-Print Network (OSTI)

Assessing the Potential of Using Traffic Simulation Model Results for Evaluating Automatic Incident of such a test-bed would be the ability to incorporate synthetic data produced by a simulation model since

Hellinga, Bruce

162

Reduced-Reference Image Quality Assessment Using A Wavelet-Domain Natural Image Statistic Model  

E-Print Network (OSTI)

Reduced-Reference Image Quality Assessment Using A Wavelet-Domain Natural Image Statistic Model information about the reference images. In this paper, we propose an RR image quality assessment method based on a natural image statistic model in the wavelet transform domain. We use the Kullback-Leibler distance

Wang, Zhou

163

Impact Assessment of Abiotic Resources in LCA: Quantitative Comparison of Selected Characterization Models  

Science Journals Connector (OSTI)

Impact Assessment of Abiotic Resources in LCA: Quantitative Comparison of Selected Characterization Models ... Resources have received significant attention in recent years resulting in development of a wide range of resource depletion indicators within life cycle assessment (LCA). ... Finally, we classify the existing methods into three groups, according to method focus and modeling approach, to aid method selection within LCA. ...

Jakob T. Rørbech; Carl Vadenbo; Stefanie Hellweg; Thomas F. Astrup

2014-09-10T23:59:59.000Z

164

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

E-Print Network (OSTI)

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

Paris-Sud XI, Université de

165

Screening model for nanowire surface-charge sensors in liquid  

E-Print Network (OSTI)

The conductance change of nanowire field-effect transistors is considered a highly sensitive probe for surface charge. However, Debye screening of relevant physiological liquid environments challenge device performance due to competing screening from the ionic liquid and nanowire charge carriers. We discuss this effect within Thomas-Fermi and Debye-Huckel theory and derive analytical results for cylindrical wires which can be used to estimate the sensitivity of nanowire surface-charge sensors. We study the interplay between the nanowire radius, the Thomas-Fermi and Debye screening lengths, and the length of the functionalization molecules. The analytical results are compared to finite-element calculations on a realistic geometry.

Martin H. Sorensen; Niels Asger Mortensen; Mads Brandbyge

2007-08-17T23:59:59.000Z

166

Assessment of Wind Power Potential for Two Contrasting Coastlines of South Africa Using a Numerical Model  

Science Journals Connector (OSTI)

A two-dimensional numerical model is used to predict near surface wind velocities, and consequently wind power, for five distinct synoptic regimes for contrasting east and west coasts of South Africa. The model results suggest that no one ...

R. D. Diab; M. Garstang

1984-12-01T23:59:59.000Z

167

Assessing the Accuracy of Contact Angle Measurements for Sessile Drops on Liquid-Repellent Surfaces  

E-Print Network (OSTI)

Gravity-induced sagging can amplify variations in goniometric measurements of the contact angles of sessile drops on super-liquid-repellent surfaces. The very large value of the effective contact angle leads to increased ...

Srinivasan, Siddarth

168

Information on Hydrologic Conceptual Models, Parameters, Uncertainty Analysis, and Data Sources for Dose Assessments at Decommissioning Sites  

SciTech Connect

This report addresses issues related to the analysis of uncertainty in dose assessments conducted as part of decommissioning analyses. The analysis is limited to the hydrologic aspects of the exposure pathway involving infiltration of water at the ground surface, leaching of contaminants, and transport of contaminants through the groundwater to a point of exposure. The basic conceptual models and mathematical implementations of three dose assessment codes are outlined along with the site-specific conditions under which the codes may provide inaccurate, potentially nonconservative results. In addition, the hydrologic parameters of the codes are identified and compared. A methodology for parameter uncertainty assessment is outlined that considers the potential data limitations and modeling needs of decommissioning analyses. This methodology uses generic parameter distributions based on national or regional databases, sensitivity analysis, probabilistic modeling, and Bayesian updating to incorporate site-specific information. Data sources for best-estimate parameter values and parameter uncertainty information are also reviewed. A follow-on report will illustrate the uncertainty assessment methodology using decommissioning test cases.

Meyer, Philip D.; Gee, Glendon W.; Nicholson, Thomas J.

2000-02-28T23:59:59.000Z

169

Modelling of cluster emission from metal surfaces under ion impact  

Science Journals Connector (OSTI)

...phase of the collision-cascade development was absent...bombarded with inert-gas ions having energies...intersection of the collision cascade with the surface, set...the thermal part of the cascade evolution: much later...with respect to that of natural Cu. Since the total...

2004-01-01T23:59:59.000Z

170

Model for a web based medical technology assessment system  

E-Print Network (OSTI)

will form the backbone of this system. Various queries can be run to produce the desired results. This system will provide a means for assessing the currently available medical technology. Based on the information present in the system clinical engineers...

Prabhu, Gopal

1999-01-01T23:59:59.000Z

171

[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

172

Empirical modeling of summer lake surface temperatures in ...  

Science Journals Connector (OSTI)

The model approximates the slow integrated response of water temperature to meteorological forcing by applying an exponential smoothing filter to air ...

173

A kinematic model for surface irrigation: Verification by experimental data  

E-Print Network (OSTI)

values are 75.52, 31.62, 36.36, and 43.9, respec- tively (Table 5). Model K nemat c Calculated Curves Advance (KWT) Observed Data ---- Recession Data Set R-IO o Data Set R-II 120 ? Data Set R-12 r- R_ 12.... \\"' IOO :- Model K nemahc / IOO... comparison of irrigation advance yielded by the kinematic wave (KW) model was made with that yielded by Model' K nemat c Observed Data 0 Data Set R-8, TI me = 44 I rn n ? Data Set R-II, T me=39 4rain Calculated Profile (KWT) .03 [ ,, ' ' _ Roth...

Singh, Vijay P.; Ram, Rama S.

174

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

E-Print Network (OSTI)

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 ...

Winter, Jonathan (Jonathan Mark)

2010-01-01T23:59:59.000Z

175

An anticipatory integrated assessment of regional acidification: The RAINS-Asia model  

SciTech Connect

Across large parts of Asia, air pollution problems are becoming more and more evident. Rainfall in some areas, including China, Japan, and Thailand, has been measured to be 10 times more acidic than unpolluted rain. Increasing evidence of acidification damage to ecosystems such as surface waters, soils, and economically important crops, is beginning to appear. In addition, urban air quality in many areas of the region continues to decrease. Current economic forecasts predict continued rapid economic growth in the region, which will bring with it increasing emissions of air pollutants, especially sulfur. The total primary energy demand in Asia currently doubles every twelve years (as compared to a world average of every 28 years). Coal is expected to continue to be the dominant energy source, with coal demand projected to increase by 65 percent per year, a rate that outpaces regional economic growth. If current trends in economic development and energy use in Asia continue, emissions of sulfur dioxide, one of the key components in acid rain, will more than triple within the next 30 years. Many ecosystems will be unable to continue to absorb these increased levels of pollution without harmful effects, thus creating a potential danger for irreversible environmental damage in many areas. In view of the potential environmental consequences of projected growth in Asian energy consumption, emissions, and air pollution, the World Bank, together with the Asian Development Bank, have funded a project to develop and implement an integrated assessment model for the acid deposition phenomenon in Asia. The Regional Air Pollution INformation and Simulation model for Asia (RAINS-Asia) is a software tool to help decision makers assess and project future trends in emissions, transport, and deposition of air pollutants, and their potential environmental effects.

Amann, M. [International Institute for Applied Systems Analysis, Laxenburg (Austria); Carmichael, G.R. [Univ. of Iowa, Iowa City, IA (United States); Foell, W. [Resource Management Associates, Madison, WI (United States)] [and others

1996-12-31T23:59:59.000Z

176

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)

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 A Thesis by JORGE LUIS MELENDEZ Submitted to the Office of Graduate Studies... of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 2006 Major Subject: Petroleum Engineering RISK ASSESSMENT OF SURFACE VS SUBSEA BLOWOUT PREVENTERS (BOPS) ON MOBILE OFFSHORE...

Melendez, Jorge Luis

2006-08-16T23:59:59.000Z

177

Bias Correction and Bayesian Model Averaging for Ensemble Forecasts of Surface Wind Direction  

E-Print Network (OSTI)

from numerical weather prediction models, which is based on a state-of-the-art circular-processing techniques for forecasts from numerical weather prediction models tend to become ineffective or inapplicableBias Correction and Bayesian Model Averaging for Ensemble Forecasts of Surface Wind Direction Le

Washington at Seattle, University of

178

MODELLING SURFACE HOAR FORMATION AND EVOLUTION ON MOUNTAIN SLOPES Simon Horton1  

E-Print Network (OSTI)

. Weather station data and forecasted data from the GEM15 numerical weather prediction model were used evaluates surface hoar size predictions made with empirical weather based models and discusses how buried and south facing slopes in the Columbia Mountains. Two models were developed to predict crystal size, one

Jamieson, Bruce

179

Comparison of Innovative Molecular Approaches and Standard Spore Assays for Assessment of Surface Cleanliness  

Science Journals Connector (OSTI)

...sampling. A more plausible explanation may be the random capture of airborne spore-bearing particles from the air within the cleanroom where the spacecraft was assembled and sampled. The low incidence of detectable spores on the surfaces of the spacecraft...

Moogega Cooper; Myron T. La Duc; Alexander Probst; Parag Vaishampayan; Christina Stam; James N. Benardini; Yvette M. Piceno; Gary L. Andersen; Kasthuri Venkateswaran

2011-06-07T23:59:59.000Z

180

Surface permeability tests: experiments and modelling for estimating effective permeability  

Science Journals Connector (OSTI)

...effective permeabilities in a two-dimensional domain with anisotropic effective permeabilities. The procedures put forward in this...1991Analytical models of the effective permeability of sand-shale reservoirsGeophys. J. Int. 105 513527( doi:10.1111...

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

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

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.

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

2013-12-01T23:59:59.000Z

182

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

SciTech Connect

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.

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

2014-05-20T23:59:59.000Z

183

Diagnostics for near-surface wind response to the Gulf Stream in a regional atmospheric model  

Science Journals Connector (OSTI)

The mechanisms acting on near-surface winds over the Gulf Stream are diagnosed using 5-year outputs of a regional atmospheric model. The diagnostics for the surface-layer momentum vector, its curl, and its convergence are developed with a clear ...

Kohei Takatama; Shoshiro Minobe; Masaru Inatsu; R. Justin Small

184

Artificial Neural Network Modeling of Surface Tension for Pure Organic Compounds  

Science Journals Connector (OSTI)

Artificial Neural Network Modeling of Surface Tension for Pure Organic Compounds ... This study investigates the applicability of artificial neural networks as an efficient tool for the prediction of pure organic compounds’ surface tensions for a wide range of temperatures. ... The most accurate network among several constructed configurations has one hidden layer with 20 neurons. ...

Aliakbar Roosta; Payam Setoodeh; Abdolhossein Jahanmiri

2011-12-09T23:59:59.000Z

185

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

E-Print Network (OSTI)

expansion near the Sun and the solar wind speed observed at earth was first noted by Levine, AltschulerDiscrepancies in the Prediction of Solar Wind using Potential Field Source Surface Model between the magnetic flux tube expansion factor (FTE) at the source surface and the solar wind speed

Zhao, Xuepu

186

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

E-Print Network (OSTI)

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

Menut, Laurent

187

Water Balance in the Amazon Basin from a Land Surface Model Ensemble  

Science Journals Connector (OSTI)

Despite recent advances in land surface modeling and remote sensing, estimates of the global water budget are still fairly uncertain. This study aims to evaluate the water budget of the Amazon basin based on several state-of-the-art land surface ...

Augusto C. V. Getirana; Emanuel Dutra; Matthieu Guimberteau; Jonghun Kam; Hong-Yi Li; Bertrand Decharme; Zhengqiu Zhang; Agnes Ducharne; Aaron Boone; Gianpaolo Balsamo; Matthew Rodell; Ally M. Toure; Yongkang Xue; Christa D. Peters-Lidard; Sujay V. Kumar; Kristi Arsenault; Guillaume Drapeau; L. Ruby Leung; Josyane Ronchail; Justin Sheffield

2014-12-01T23:59:59.000Z

188

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

E-Print Network (OSTI)

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

Fayer, Michael D.

189

Concepts, Instruments, and Model Systems that Enabled the Rapid Evolution of Surface Science  

SciTech Connect

Over the past forty years, surface science has evolved to become both an atomic scale and a molecular scale science. Gerhard Ertl's group has made major contributions in the field of molecular scale surface science, focusing on vacuum studies of adsorption chemistry on single crystal surfaces. In this review, we outline three important aspects which have led to recent advances in surface chemistry: the development of new concepts, in situ instruments for molecular scale surface studies at buried interfaces (solid-gas and solid-liquid), and new model nanoparticle surface systems, in addition to single crystals. Combined molecular beam surface scattering and low energy electron diffraction (LEED)- surface structure studies on metal single crystal surfaces revealed concepts, including adsorbate-induced surface restructuring and the unique activity of defects, atomic steps, and kinks on metal surfaces. We have combined high pressure catalytic reaction studies with ultra high vacuum (UHV) surface characterization techniques using a UHV chamber equipped with a high pressure reaction cell. New instruments, such as high pressure sum frequency generation (SFG) vibrational spectroscopy and scanning tunneling microscopy (STM) which permit molecular-level surface studies have been developed. Tools that access broad ranges of pressures can be used for both the in situ characterization of solid-gas and solid-liquid buried interfaces and the study of catalytic reaction intermediates. The model systems for the study of molecular surface chemistry have evolved from single crystals to nanoparticles in the 1-10 nm size range, which are currently the preferred media in catalytic reaction studies.

Somorjai, Gabor A.; Park, Jeong Y.

2009-01-10T23:59:59.000Z

190

Mapping surface fuels using LIDAR and multispectral data fusion for fire behavior modeling  

E-Print Network (OSTI)

, LIDAR derived data provides accurate estimates of surface fuel parameters efficiently and accurately over extensive areas of forests. This study demonstrates the importance of using accurate maps of fuel models derived using new LIDAR remote sensing...

Mutlu, Muge

2009-05-15T23:59:59.000Z

191

Parameter estimation of coupled water and energy balance models based on stationary constraints of surface states  

E-Print Network (OSTI)

[1] We use a conditional averaging approach to estimate the parameters of a land surface water and energy balance model and then use the estimated parameters to partition net radiation into latent, sensible, and ground ...

Sun, Jian

192

Nonlinear Time Domain Modeling and Simulation of Surface and Embedded NPPS  

Energy.gov (U.S. Department of Energy (DOE))

Nonlinear Time Domain Modeling and Simulation of Surface and Embedded NPPS Boris Jeremic with contributions from Federico Pisanò, Jose Abell, Kohei Watanabe, Chao Luo University of California, Davis Lawrence Berkeley National Laboratory, Berkeley DOE NPH, October 2014

193

Near-surface wind estimates using statistics from a planetary boundary-layer model  

Science Journals Connector (OSTI)

This paper shows the possibilities of a procedure for estimating near-surface wind statistics, by means of the numerical integration of a simple boundary-layer model with a second-order turbulent closure. Stan...

J. C. Labraga

1988-04-01T23:59:59.000Z

194

The Surface-Pressure Signature of Atmospheric Tides in Modern Climate Models  

E-Print Network (OSTI)

Although atmospheric tides driven by solar heating are readily detectable at the earth’s surface as variations in air pressure, their simulations in current coupled global climate models have not been fully examined. This ...

Covey, Curt

195

The Niobrara River Basin Study: Using Various Models to Assess  

E-Print Network (OSTI)

Seminar Series Brandi Flyr, Ph.D. Integrated Water Management Division Nebraska Department of Natural;#12;Integrated Water Management Identify Management Setting Assess Water Resources Understand & Predict Set effects of various water management strategies in order to develop water management tools #12;Goals

Farritor, Shane

196

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

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Categorical Exclusion Determination Imaging, Characterizing, and Modeling of Fracture Networks and Fluid Flow in EGS Reservoirs Predicting Stimulation Response...

197

Predictions from an Ising-like Statistical Mechanical Model on the Dynamic and Thermodynamic Effects of Protein Surface Electrostatics  

Science Journals Connector (OSTI)

Predictions from an Ising-like Statistical Mechanical Model on the Dynamic and Thermodynamic Effects of Protein Surface Electrostatics ...

Athi N. Naganathan

2012-10-05T23:59:59.000Z

198

Models used to assess the performance of photovoltaic systems.  

SciTech Connect

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.

Stein, Joshua S.; Klise, Geoffrey T.

2009-12-01T23:59:59.000Z

199

Water and Surface Energy Balance Modeling in Botswana  

Science Journals Connector (OSTI)

From January-March 1989 an intensive field campaign was held in the eastern savanna of Botswana, Africa, to collect ground data to parameterize models which can be used to determine the physical status and water-balance terms of the earth's ...

A. A. Van de Griend; M. Owe; H. F. Vugts; S. D. Prince

1989-11-01T23:59:59.000Z

200

United: How one computer model makes Texas surface water management possible  

E-Print Network (OSTI)

Story by Leslie Lee Summer 2013 tx H2O 3 Photo by Kathleen Phillips, Texas A&M AgriLife UNITED How one computer model makes Texas surface water management possible Managing surface water supplies in Texas is complex, to say the least. Multiple... of conditions. W#15;P enables surface water managers throughout Texas to allocate water resources, plan for the future and ensure there is enough water for environmental as well as human needs. A statewide surface water permitting system is born Prior...

Lee, Leslie

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Assessing the protective effect of mountain forests against rockfall using a 3D simulation model  

E-Print Network (OSTI)

Assessing the protective effect of mountain forests against rockfall using a 3D simulation model and compared the results obtained with the 3D simulation model RockyFor with empirical data on tree impacts; Rockfall; 3D simulation model; Swiss Alps 1. Introduction Many mountain forests effectively protect people

Stoffel, Markus

202

Assessing resilience and state-transition models with historical records of cheatgrass Bromus tectorum  

E-Print Network (OSTI)

Assessing resilience and state-transition models with historical records of cheatgrass Bromus. Bestelmeyer2 and X. Ben Wu1 1 Department of Ecosystem Science and Management, Texas A&M University, 2138 TAMU. This requires management frameworks that can assess ecosystem dynamics, both within and between alternative

203

Sub-AQUA: real-value quality assessment of protein structure models  

E-Print Network (OSTI)

Sub-AQUA: real-value quality assessment of protein structure models Yifeng David Yang1, Preston of Natural Science, Chung-Ang University, Seoul, Korea, 3 Department of Computer Science, College of Science developed quality assessment methods, which predict real value of the global and local quality of protein

Kihara, Daisuke

204

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

E-Print Network (OSTI)

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

Laughlin, Robert B.

205

On the use of fuzzy inference techniques in assessment models: part II: industrial applications  

Science Journals Connector (OSTI)

In this paper, we study the applicability of the monotone output property and the output resolution property in fuzzy assessment models to two industrial Failure Mode and Effect Analysis (FMEA) problems. First, t...

Kai Meng Tay; Chee Peng Lim

2008-09-01T23:59:59.000Z

206

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

E-Print Network (OSTI)

. Determination of household energy using ?fingerprints? from energy billing data. Energy Research 10(4), pp: 393?405. [5] Snakin JPA, 2000. An engineering model for heating energy and emission assessment The case of North Karelia, Finland. Applied Energy...

Radhi, H.; Fikry, F.

2010-01-01T23:59:59.000Z

207

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

E-Print Network (OSTI)

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

Cirpka, Olaf Arie

208

A Model for Fuzzy Logic Assessment of Real Estate Investment Risks  

Science Journals Connector (OSTI)

Assessing the real estate investment risks is a major issue for the responsible management and the sustainable regional development. The paper proposes a fuzzy logic model for complex estimation of the real estate

Plamena Zlateva; Dimiter Velev…

2011-01-01T23:59:59.000Z

209

Using Noncompensatory Models in Cognitive Diagnostic Mathematics Assessments: An Evaluation Based on Empirical Data  

E-Print Network (OSTI)

The present study evaluates the performance of four noncompensatory cognitive diagnostic models -- AHM, DINA, Fusion, and Bayesian Networks -- using both formative and large-scale mathematics assessments (Fraction dataset, ...

Zhao, Fei

2013-08-31T23:59:59.000Z

210

METHODOLOGY ARTICLE Open Access Quality assessment of protein model-structures  

E-Print Network (OSTI)

similar to proteins functionally similar to the prediction target. Whereas DALI is used to measure structure similarity, protein functional similarity is quantified using standardized and hierarchical model quality assessment method, the other is its modification, which provides a relative measure

Nebel, Jean-Christophe

211

Models Used to Assess the Performance of Photovoltaic Systems  

Energy.gov (U.S. Department of Energy (DOE))

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.

212

Assessment  

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

Assessment of the Surveillance Program of the High-Level Waste Storage Tanks at Hanford :.I LALI iE REJ 163 ROOM 1t 4 F77L. -77 .:earmn OfEeg Asitn Sertr fo niomn 4 z. r...

213

Evidence of acid-base interactions between amines and model indoor surfaces  

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

Evidence of acid-base interactions between amines and model indoor surfaces Evidence of acid-base interactions between amines and model indoor surfaces by ATR-FTIR spectroscopy Title Evidence of acid-base interactions between amines and model indoor surfaces by ATR-FTIR spectroscopy Publication Type Journal Article LBNL Report Number LBNL-63480 Year of Publication 2007 Authors Destaillats, Hugo, Brett C. Singer, and Lara A. Gundel Journal Atmospheric Environment Volume 41 Start Page Chapter Pagination 3177-3181 ISBN Number 1352-2310 Keywords acid-base, cellulose, gypsum, nicotine, pyridine, sorption, surface materials Abstract Molecular associations of pyridine with cellulose and gypsum, surrogates for common indoor surface materials, were studied using an attenuated total reflection (ATR)-Fourier transform infrared (FTIR) spectrophotometric method. The purpose of this study was to gain insight into the molecular interactions of amines with well-characterized materials that affect their partitioning between indoor air and surfaces. The experimental results suggest the presence of at least two sorptive states for volatile and semivolatile amines, attributed to the chemisorbed species and to a more labile surface state (i.e., physisorbed pyridine). Both exhibited spectroscopic signatures corresponding to aromatic C-H stretching modes (2950-3100 cm-1) in the studied spectral region. Chemisorbed pyridine could be identified by the presence of additional IR signals in the N-H and O-H stretching region of the spectrum (2900-3600 cm-1). During desorption under a stream of N2, surface enrichment in the chemisorbed species was evidenced by a slower reduction of the absorbance of the broad band at 2900-3600 cm-1 in relation to the total pyridine absorbance change. This spectroscopic evidence for acid-base interactions between amines and surfaces is consistent with the desorption behavior observed in previous work for nicotine from model surfaces.

214

An investigation into the use of biokinetic models when assessing intakes of plutonium  

E-Print Network (OSTI)

AN INVESTIGATION INTO THE USE OF BIOKINETIC MODELS WHEN ASSESSING INTAKES OF PLUTONIUM A Thesis by BRIAN ANDREW HRYCUSHKO Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 2008 Major Subject: Health Physics AN INVESTIGATION INTO THE USE OF BIOKINETIC MODELS WHEN ASSESSING INTAKES OF PLUTONIUM A Thesis by BRIAN ANDREW HRYCUSHKO Submitted...

Hrycushko, Brian Andrew

2008-10-10T23:59:59.000Z

215

Statewide and Electricity-Sector Models for Economic Assessments of  

E-Print Network (OSTI)

economic models applied to such diverse fields as climate change policy, alternative- fueled vehicles, fuel Economic Research Organization and Affiliate Faculty with the Public Policy Center UHM. Paul Bernstein, Ph....................................................................................................................... 6 2. The Hawaii Computable General Equilibrium Model (H-CGE)............................ 8 2.a. Data

216

Using GIS and numerical modeling to assess subsidence over abandoned mines  

SciTech Connect

The US Bureau of Mines (USBM) has been developing techniques to assess surface subsidence over abandoned coal mines. One technique has involved estimation of stress acting on every pillar of an abandoned mine then comparing it to pillar strength and floor bearing capacity. This required computations for several thousand pillars for one mine. Mine maps are digitized and saved as a computer drawing file. Then the tributary area loading each pillar was determined graphically and outlined. Geographic Information System (GIS) software was used to compute the ratio of pillar area to tributary area for each pillar and then divide the average overburden stress by this ratio to compute an estimated pillar stress. Numerical modeling was then used to analyze a two-dimensional cross section of the overburden and mine, and provide an independent estimate of stresses. Based on published data for floor bearing capacity and pillar load capacity, GIS was used to perform a mine-wide classification of pillars according to stress level. An example of this analysis and classification is presented in this paper for an abandoned coal mine in the Illinois Basin. The mine had been operated in the Herrin No. 6 Seam at a depth of 60 in with an average overburden stress of 1.4 MPa. It was found that pillars with estimated stresses greater than 5 MPa correlated with historical subsidence events. Due to the greater detail considered in this approach, it provides a fundamental basis for the assessment of subsidence risk since it incorporates the geometry of mine pillars and entries as well as the ultimate strength of the pillars and floor.

O`Connor, K.M. [GeoTDR, Inc., Apple Valley, MN (United States); Siekmeier, J.A. [Braun Intertec Corp., Minneapolis, MN (United States); Stache, J.

1996-12-31T23:59:59.000Z

217

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

SciTech Connect

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.

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

218

Assessment of Structural and Clad Materials for Fission Surface Power Systems  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

ORNL/LTR-2011/351 ORNL/LTR-2011/351 Reactor Pressure Vessel Task of Light Water Reactor Sustainability Program: Initial Assessment of Thermal Annealing Needs and Challenges September 2011 Prepared by R.K. Nanstad, Oak Ridge National Laboratory and W. L. Server, ATI Consulting This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product,

219

Investigating the Ability of a Land Surface Model to Simulate Streamflow with the Accuracy of Hydrological Models: A Case Study Using MOPEX Materials  

Science Journals Connector (OSTI)

In the Model Parameter Estimation Experiment (MOPEX) project, after calibration of model parameters, complex rainfall–runoff hydrological models (HMs) simulated streamflow better than land surface models (LSMs), including the Soil–Water–...

Olga N. Nasonova; Yeugeniy M. Gusev; Yeugeniy E. Kovalev

2009-10-01T23:59:59.000Z

220

Quantitative Microbial Risk Assessment Models for Consumption of Raw Vegetables Irrigated with Reclaimed Water  

Science Journals Connector (OSTI)

...The practice of adding water to cut surfaces to keep...waxed boxes, wherein water pools. Feeding damage by insects...Agriculture methods Conservation of Natural Resources...Food Contamination Fresh Water virology Models, Biological...

Andrew J. Hamilton; Frank Stagnitti; Robert Premier; Anne-Maree Boland; Glenn Hale

2006-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Sponge Model for the Kinetics of Surface Thermal Decomposition of Microcrystalline Solids: Application to HMX  

E-Print Network (OSTI)

pitted, spongy, porous structure. It is for this reason that it would be inappropriate to use an "onion pealing" kinetic model analogous to that used by Eyring and co-workers2 to treat radial inward burning of solid fuels. In the radial burning model, the outer surface of the solid is consumed before any

Simons, Jack

222

Analytical model for ion angular distribution functions at rf biased surfaces with collisionless plasma sheaths  

E-Print Network (OSTI)

Analytical model for ion angular distribution functions at rf biased surfaces with collisionless plasma sheaths Laxminarayan L. Rajaa) Department of Aerospace Engineering and Engineering Mechanics The article presents an analytical model for evaluation of ion angular distribution functions IADFs at a radio

Raja, Laxminarayan L.

223

Electric field noise above surfaces: a model for heating rate scaling law in ion traps  

E-Print Network (OSTI)

We present a model for the scaling laws of the electric field noise spectral density as a function of the distance, $d$, above a conducting surface. Our analytical approach models the patch potentials by introducing a correlation length, $\\zeta$, of the electric potential on the surface. The predicted scaling laws are in excellent agreement with two different classes of experiments (cold trapped ions and cantilevers), that span at least four orders of magnitude of $d$. According to this model, heating rate in miniature ion traps could be greatly reduced by proper material engineering.

Romain Dubessy; Thomas Coudreau; Luca Guidoni

2008-12-17T23:59:59.000Z

224

Biological assessment of robust noise models in microarray data analysis  

Science Journals Connector (OSTI)

......Compatibility with our ANOVA model suggests applying a Kruskal-Wallis permutation test (cf. Lee et al., 2005) and...under KW perm. illustrate the agreements of the Kruskal-Wallis permutation test with the robust parametric method......

A. Posekany; K. Felsenstein; P. Sykacek

2011-03-15T23:59:59.000Z

225

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

Open Energy Info (EERE)

is that there are new solutions to heat extraction from an as-created, enhanced fracture system of EGS. The project will develop a new THMC simulation model with new...

226

GIS and plume dispersion modeling for population exposure assessment  

E-Print Network (OSTI)

. Traditional methods of dispersion modeling for the permitting of new sources and the monitoring of existing sources have allowed much room for error in terms of the effect of the pollutants on nearby populations (Hardikar, 1995). The capabilities of GIS...

Archer, Jeffrey Keith

2012-06-07T23:59:59.000Z

227

Modeling Liquid Bridge between Surfaces with Contact Angle Hysteresis  

Science Journals Connector (OSTI)

Another study on the liquid bridge was done by Fortes,(12) where a theoretical model was established to obtain the profiles of axisymmetric liquid bridges between two identical parallel plates. ... In this study, according to different boundary conditions, liquid bridges were classified as ? bridge (the plates were infinite and the contact angle ? were specified at the liquid–plate boundaries) and r bridge (the plates were circular and of radius r, and the liquid–plate contact lines were pinned at the edge of the plates), and the profiles of liquid bridges in both cases were obtained at given separation between the plates. ... Both symmetric and asymmetric liquid bridges were analyzed, and the effects of CAH on the liquid bridge profile, the adhesion force, and the energy cost during a loading cycle are discussed. ...

H. Chen; A. Amirfazli; T. Tang

2013-02-20T23:59:59.000Z

228

Assessment of solution uncertainties in single-column modeling frameworks  

SciTech Connect

Single-column models (SCMs) have been extensively promoted in recent years as an effective means to develop and test physical parameterizations targeted for more complex three-dimensional climate models. Although there are some clear advantages associated with single-column modeling, there are also some significant disadvantages, including the absence of large-scale feedbacks. Basic limitations of an SCM framework can make it difficult to interpret solutions, and at times contribute to rather striking failures to identify even first-order sensitivities as they would be observed in a global climate simulation. This manuscript will focus on one of the basic experimental approaches currently exploited by the single-column modeling community, with an emphasis on establishing the inherent uncertainties in the numerical solutions. The analysis will employ the standard physics package from the NCAR CCM3 and will illustrate the nature of solution uncertainties that arise from nonlinearities in parameterized physics. The results of this study suggest the need to make use of an ensemble methodology when conducting single-column modeling investigations.

Hack, J.J.; Pedretti, J.A.

2000-01-15T23:59:59.000Z

229

3-D seismic modelling of general material anisotropy in the presence of the free surface by a Chebyshev spectral method  

Science Journals Connector (OSTI)

......modelling in general anisotropic media is presented...the qSV and SH waves. Anisotropic free-surface modelling...wavefronts of Green River shale after 375 ms propagation...in the Green River shale model with 45" inclined...qSH-guided SH wave. Anisotropic free-surface modelling......

Ekkehart Tessmer

1995-05-01T23:59:59.000Z

230

Assessing the consistency between short-term global temperature trends in observations and climate model projections  

E-Print Network (OSTI)

Assessing the consistency between short-term global temperature trends in observations and climate model projections is a challenging problem. While climate models capture many processes governing short-term climate fluctuations, they are not expected to simulate the specific timing of these somewhat random phenomena - the occurrence of which may impact the realized trend. Therefore, to assess model performance, we develop distributions of projected temperature trends from a collection of climate models running the IPCC A1B emissions scenario. We evaluate where observed trends of length 5 to 15 years fall within the distribution of model trends of the same length. We find that current trends lie near the lower limits of the model distributions, with cumulative probability-of-occurrence values typically between 5 percent and 20 percent, and probabilities below 5 percent not uncommon. Our results indicate cause for concern regarding the consistency between climate model projections and observed climate behavior...

Michaels, Patrick J; Christy, John R; Herman, Chad S; Liljegren, Lucia M; Annan, James D

2013-01-01T23:59:59.000Z

231

Assessing security threat scenarios for utility-based reputation model in grids  

Science Journals Connector (OSTI)

Trust and reputation models play an important role in enabling trusted computations over large-scale distributed grids. Many models have been recently proposed and implemented within trust management systems. Nevertheless, the existing approaches usually assess performance of models in terms of resource management while less attention is paid to the analysis of security threat scenarios for such models. In this paper, we assess the most important and critical security threats for a utility-based reputation model in grids. The existing model is extended to address these threat scenarios. With simulations that were run using data collected from the EGEE Grid-Observatory project, we analyse efficiency of the utility-based reputation model against these threats.

Olga Kussul; Nataliia Kussul; Sergii Skakun

2013-01-01T23:59:59.000Z

232

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

E-Print Network (OSTI)

- 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

Boyer, Edmond

233

Building a comprehensive quantitative risk assessment model for lung cancer  

Science Journals Connector (OSTI)

...Res, Volume 46, 2005 Building a comprehensive quantitative...including identification of multi-collinearities and...and resulted in model multi-collinearities. When...asbestos exposure, family history of LC and years...factors of emphysema, family history of LC, years...

Carol J. Etzel; Qing Zhang; Matthew Schabath; Qiong Dong; Xifeng Wu; Qingyi Wei; Margaret Spitz; and Christopher I. Amos

2005-05-01T23:59:59.000Z

234

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

E-Print Network (OSTI)

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.

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

2013-10-14T23:59:59.000Z

235

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

E-Print Network (OSTI)

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.

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

2006-01-14T23:59:59.000Z

236

Assessing certainty and uncertainty in riparian habitat suitability models by identifying parameters with extreme outputs  

Science Journals Connector (OSTI)

The aim of this paper is to introduce a computationally efficient uncertainty assessment approach using an index-based habitat suitability model. The approach focuses on uncertainty in ecological knowledge regarding parameters of index curves and weights. ... Keywords: Habitat model, Riparian vegetation, Suitability index, Uncertainty

Baihua Fu, Joseph H. A. Guillaume

2014-10-01T23:59:59.000Z

237

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

E-Print Network (OSTI)

1 A Multi-Model Assessment of Regional Climate Disparities Caused by Solar Geoengineering Brunswick, NJ. 5 Canadian Centre for Climate Modeling and Analysis, Environment Canada, Toronto, Ontario, Canada. 6 School of Earth and Ocean Sciences, University of Victoria, Victoria, British Columbia, Canada

Robock, Alan

238

A Conceptual Model of the Surface Salinity Distribution in the Oceanic Hadley Cell JOHAN NILSSON AND HEINER KRNICH  

E-Print Network (OSTI)

A Conceptual Model of the Surface Salinity Distribution in the Oceanic Hadley Cell JOHAN NILSSON in the oceanic Hadley cell is presented. The model pertains to the region of tropical easterly surface winds of the near-surface air is constant, the salinity variation in the oceanic Hadley cell varies essentially

Nilsson, Johan

239

Update and assessment of geothermal economic models, geothermal fluid flow and heat distribution models, and geothermal data bases  

SciTech Connect

Numerical simulation models and data bases that were developed for DOE as part of a number of geothermal programs have been assessed with respect to their overall stage of development and usefulness. This report combines three separate studies that focus attention upon: (1) economic models related to geothermal energy; (2) physical geothermal system models pertaining to thermal energy and the fluid medium; and (3) geothermal energy data bases. Computerized numerical models pertaining to the economics of extracting and utilizing geothermal energy have been summarized and catalogued with respect to their availability, utility and function. The 19 models that are discussed in detail were developed for use by geothermal operators, public utilities, and lending institutions who require a means to estimate the value of a given resource, total project costs, and the sensitivity of these values to specific variables. A number of the models are capable of economically assessing engineering aspects of geothermal projects. Computerized simulations of heat distribution and fluid flow have been assessed and are presented for ten models. Five of the models are identified as wellbore simulators and five are described as reservoir simulators. Each model is described in terms of its operational characteristics, input, output, and other pertinent attributes. Geothermal energy data bases are reviewed with respect to their current usefulness and availability. Summaries of eight data bases are provided in catalogue format, and an overall comparison of the elements of each data base is included.

Kenkeremath, D. (ed.)

1985-05-01T23:59:59.000Z

240

Edge plasma modeling of limiter surfaces in a Tokamak divertor configuration  

SciTech Connect

During the startup phase of a tokamak the plasma configuration may evolve from a limiter to a divertor configuration. Some of the particle and heat flux from the core will be deposited on material surfaces near the separatrix instead of the divertor plates. Examples of such surfaces include the center-post in most tokamaks, baffles near the x-point that create closed divertors, and outboard limiter surfaces. Two-dimensional edge plasma models for tokamak divertor configurations typically give detailed information about the particle and heat fluxes on the divertor plates, but yield little or no information about fluxes on these other localized surfaces near the core plasma. To realistically model the startup phase of a tokamak it is necessary to compute the plasma interaction with both limiter and divertor surfaces. The UEDGE code [l] has been modified to include these limiter surfaces. In this report we present simulation results for an idealized ITER [2] startup configuration with variations in the limiter penetration depth and surface shape.

Rensink, M. E., LLNL

1998-05-11T23:59:59.000Z

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Modeling shallow?water propagation with an appropriate sea?surface roughness spectrum  

Science Journals Connector (OSTI)

Predictions for shallow?water acoustic propagation are usually accomplished assuming a deep?water spectrum for the sea surface roughness. In addition the effect of surface roughness is normally included through a loss mechanism. However for waveguide propagation the surface roughness mainly causes a redistribution of energy and therefore the use of an accurate model to handle roughness is essential to obtaining accurate results. In order to properly model shallow?water surface roughness the parametric spectrum GONO [Sanders and Bruinsma Wave Dynamics and Radio Probing of the Ocean Surface edited by O. M. Phillips and K. Hassemann (Plenum New York 1986) pp. 615–637] has been implemented. This spectrum is appropriate for wind?driven surfaces in waters ranging in depth from 15 to 100 m. To investigate the impact that different spectra has on the propagating field predictions using GONO and Pierson–Moskowitz spectra are compared for different environments and at frequencies typical of active and passive sonars. An acoustic propagationmodel which includes a conformal mapping algorithm to properly handle sea surface roughness [Norton et al. J. Acoust. Soc. Am. 97 2173–2180 (1995)] is used to generate the numerical results. [Work supported by ONR.

Guy V. Norton; Jorge C. Novarini

1996-01-01T23:59:59.000Z

242

The effect of ozone on nicotine desorption from model surfaces:evidence for heterogeneous chemistry  

SciTech Connect

Assessment of secondhand tobacco smoke exposure using nicotine as a tracer or biomarker is affected by sorption of the alkaloid to indoor surfaces and by its long-term re-emission into the gas phase. However, surface chemical interactions of nicotine have not been sufficiently characterized. Here, the reaction of ozone with nicotine sorbed to Teflon and cotton surfaces was investigated in an environmental chamber by monitoring nicotine desorption over a week following equilibration in dry or humid air (65-70 % RH). The Teflon and cotton surfaces had N{sub 2}-BET surface areas of 0.19 and 1.17 m{sup 2} g{sup -1}, and water mass uptakes (at 70 % RH) of 0 and 7.1 % respectively. Compared with dry air baseline levels in the absence of O{sub 3}, gas phase nicotine concentrations decrease, by 2 orders of magnitude for Teflon after 50 h at 20-45 ppb O{sub 3}, and by a factor of 10 for cotton after 100 h with 13-15 ppb O{sub 3}. The ratios of pseudo first-order rate constants for surface reaction (r) to long-term desorption (k) were r/k = 3.5 and 2.0 for Teflon and cotton surfaces, respectively. These results show that surface oxidation was competitive with desorption. Hence, oxidative losses could significantly reduce long-term re-emissions of nicotine from indoor surfaces. Formaldehyde, N-methylformamide, nicotinaldehyde and cotinine were identified as oxidation products, indicating that the pyrrolidinic N was the site of electrophilic attack by O{sub 3}. The presence of water vapor had no effect on the nicotine-O{sub 3} reaction on Teflon surfaces. By contrast, nicotine desorption from cotton in humid air was unaffected by the presence of ozone. These observations are consistent with complete inhibition of ozone-nicotine surface reactions in an aqueous surface film present in cotton but not in Teflon surfaces.

Destaillats, Hugo; Singer, Brett C.; Lee, Sharon K.; Gundel, LaraA.

2005-05-01T23:59:59.000Z

243

Assessment  

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

Genetic Genetic Variability of Cell Wall Degradability for the Selection of Alfalfa with Improved Saccharification Efficiency Marc-Olivier Duceppe & Annick Bertrand & Sivakumar Pattathil & Jeffrey Miller & Yves Castonguay & Michael G. Hahn & Réal Michaud & Marie-Pier Dubé # Her Majesty the Queen in Right of Canada 2012 Abstract Alfalfa (Medicago sativa L.) has a high potential for sustainable bioethanol production, particularly because of its low reliance on N fertilizer. We assessed near-infrared reflec- tance spectroscopy (NIRS) as a high-throughput technique to measure cell wall (CW) degradability in a large number of lignified alfalfa stem samples. We also used a powerful immu- nological approach, glycome profiling, and chemical analyses to increase our knowledge of the composition of CW poly- saccharides of alfalfa stems with various levels

244

A free energy model and availability analysis for onset of condensation on rigid and liquid surfaces in moist air  

Science Journals Connector (OSTI)

Abstract A thermodynamic model based on changes in Gibbs free energy and availability is developed for onset of heterogeneous condensation on subcooled rigid and liquid surfaces in moist air. Effects of wettability of the wall, subcooled wall temperature, relative humidity and dew point temperature of the surrounding air on critical radii for heterogeneous condensation on a rigid surface are investigated based on the change of Gibbs free energy. From the analysis of changes in availability, it is found that onset of droplet condensation is easier to occur on a hydrophilic surface than on a hydrophobic surface, in moist air than in a dry air environment, on a colder surface than a warmer surface, on a liquid surface than a rigid surface. It is also found that condensation droplet occurs earlier on oil surfaces with small surface tensions than on oil surfaces with large surface tensions.

Luhang Yang; Xiaojun Quan; Ping Cheng; Zhiming Cheng

2014-01-01T23:59:59.000Z

245

Model for quantitative risk assessment on naturally ventilated metering-regulation stations for natural gas  

Science Journals Connector (OSTI)

Abstract The paper presents a model for quantitative risk assessment on metering stations and metering-regulation stations for natural gas with natural ventilation. The model enables the assessment of risk for people who live in the vicinity of these stations and complements the existing models for risk assessment on natural gas pipelines. It is based on risk assessment methods suggested in relevant guides, recommendations and standards. Explosion and jet fire are considered as major hazardous events and are modelled according to analytical models and empirical data. Local or other accessible databases are used for modelling of event frequencies and ignition probabilities. A case study on a sample station is carried out. For each hazardous event, fault tree and event tree analysis is performed. Results show influence of each hazardous event on the whole risk relative to the distance from the hazardous source. Ventilation is found to be a significant factor in determination of risk magnitude; its influence on individual risk is presented in a quantitative way. The model should be of use for pipeline operators as well as for environmental- and urban planners.

Tom Bajcar; Franc Cimerman; Brane Širok

2014-01-01T23:59:59.000Z

246

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

E-Print Network (OSTI)

THE DETECTION AND MODELLING DF SURFACE THERMAL STRUCTURES AND GROUND WATER DISCHARGES A Thesis by DOUGLAS YINCENT ROBERTS Subm1tted to the Graduate Col leqe of Texas A&M University in part1al fulf1llment of the requirements or the degree... of MASTER OF SCIENCE August IgSS Major Subject: Geophys1cs THE DETECTION AND MODELLING OF SURFACE THERMAL STRUCTURES AND GROUND HATER DISCHARGES A Thesis DOUGLAS VINCENT ROBERTS Approved as to style and content by: Earl . oskins (Chair of Committee...

Roberts, Douglas Vincent

2012-06-07T23:59:59.000Z

247

Improvement of modelling capabilities for assessing urban contamination : The EMRAS Urban Remediation Working Group.  

SciTech Connect

The Urban Remediation Working Group of the International Atomic Energy Agency's Environmental Modeling for Radiation Safety (EMRAS) programme was established to improve modeling and assessment capabilities for radioactively contaminated urban situations, including the effects of countermeasures. An example of the Working Group's activities is an exercise based on Chernobyl fallout data in Ukraine, which has provided an opportunity to compare predictions among several models and with available measurements, to discuss reasons for discrepancies, and to identify areas where additional information would be helpful.

Thiessen, K. M.; Batandjieva, B.; Andersson, K. G.; Arkhipov, A.; Charnock, T. W.; Gallay, F.; Gaschak, S.; Golikov, V.; Hwang, W. T.; Kaiser, J. C.; Kamboj, S.; Steiner, M.; Tomas, J.; Trifunovic, D.; Yu, C.; Ziemer, R. L.; Zlobenko, B.; Environmental Science Division; SENES Oak Ridge; IAEA; Riso National Lab.; Chernobyl Center for Nuclear Safety; Health Protection Agency; IRSN; Inst. of Radiation Hygene of the Ministry of Public Health, Russian Federation; KAERI, Republic of Korea; GSF, Germany; BfS, Germany; CPHR, Cuba; State Office for Radiation Protection, Croatia; AECL, Canada; National Academy of Science, Ukraine

2008-01-01T23:59:59.000Z

248

Model heterogeneous acid catalysts and metal-support interactions: A combined surface science and catalysis study  

SciTech Connect

This (<100 [Angstrom]) silica-alumina layers were tested as potential model heterogeneous acid catalysts for combined surface science and catalysis studies. Three preparation methods were used: oxidation of r3 [times] r3 R30 Al/Si(111) structure in UHV; deposition on Si(lll) from aqueous solution; and argon ion beam sputter deposition in UHV. The homogeneous thin layers are amorphous, and the chemical environment of surface atoms is similar to that of Si, Al and oxygen atoms on high surface area acid catalysts. Since the ion beam-deposited thin layer of silica-alumina has the same composition as the target zeolite this deposition method is a promising tool to prepare model catalysts using practical catalyst targets. The silica-alumina layers are active in cumene cracking, a typical acid catalyzed reaction. In order to clearly distinguish background reactions and the acid catalyzed reaction at least 20 cm[sup 2] catalyst surface area is needed. Two series of model platinum-alumina catalysts were prepared in a combined UHV -- high pressure reactor cell apparatus by depositing alumina on polycrystalline Pt foil and by vapor depositing Pt on a thin alumina layer on Au. Both model surfaces have been prepared with and without chlorine. AES, CO desorption as well as methyl cyclopentane (MCP) hydrogenolysis studies indicate that the Pt surface area is always higher if a chlorination step is involved. Selectivity patterns in MCP ring opening on Pt-on-alumina'' and on alumina-on-Pt'' are different; only the former is a linear combination of selective and statistical ring opening. Product distribution, however, changes with coverage and reaction time. The properties of the two model catalyst systems and role of chlorine in MCP hydrogenolysis are also discussed.

Boszormenyi, I.

1991-05-01T23:59:59.000Z

249

Model heterogeneous acid catalysts and metal-support interactions: A combined surface science and catalysis study  

SciTech Connect

This (<100 {Angstrom}) silica-alumina layers were tested as potential model heterogeneous acid catalysts for combined surface science and catalysis studies. Three preparation methods were used: oxidation of r3 {times} r3 R30 Al/Si(111) structure in UHV; deposition on Si(lll) from aqueous solution; and argon ion beam sputter deposition in UHV. The homogeneous thin layers are amorphous, and the chemical environment of surface atoms is similar to that of Si, Al and oxygen atoms on high surface area acid catalysts. Since the ion beam-deposited thin layer of silica-alumina has the same composition as the target zeolite this deposition method is a promising tool to prepare model catalysts using practical catalyst targets. The silica-alumina layers are active in cumene cracking, a typical acid catalyzed reaction. In order to clearly distinguish background reactions and the acid catalyzed reaction at least 20 cm{sup 2} catalyst surface area is needed. Two series of model platinum-alumina catalysts were prepared in a combined UHV -- high pressure reactor cell apparatus by depositing alumina on polycrystalline Pt foil and by vapor depositing Pt on a thin alumina layer on Au. Both model surfaces have been prepared with and without chlorine. AES, CO desorption as well as methyl cyclopentane (MCP) hydrogenolysis studies indicate that the Pt surface area is always higher if a chlorination step is involved. Selectivity patterns in MCP ring opening on ``Pt-on-alumina`` and on ``alumina-on-Pt`` are different; only the former is a linear combination of selective and statistical ring opening. Product distribution, however, changes with coverage and reaction time. The properties of the two model catalyst systems and role of chlorine in MCP hydrogenolysis are also discussed.

Boszormenyi, I.

1991-05-01T23:59:59.000Z

250

Advances in National Capabilities for Consequence Assessment Modeling of Airborne Hazards  

SciTech Connect

This paper describes ongoing advancement of airborne hazard modeling capabilities in support of multiple agencies through the National Atmospheric Release Advisory Center (NARAC) and the Interagency Atmospheric Modeling and Atmospheric Assessment Center (IMAAC). A suite of software tools developed by Lawrence Livermore National Laboratory (LLNL) and collaborating organizations includes simple stand-alone, local-scale plume modeling tools for end user's computers, Web- and Internet-based software to access advanced 3-D flow and atmospheric dispersion modeling tools and expert analysis from the national center at LLNL, and state-of-the-science high-resolution urban models and event reconstruction capabilities.

Nasstrom, J; Sugiyama, G; Foster, K; Larsen, S; Kosovic, B; Eme, B; Walker, H; Goldstein, P; Lundquist, J; Pobanz, B; Fulton, J

2007-11-26T23:59:59.000Z

251

The development of an integrated model for assessing sustainability of complex systems  

Science Journals Connector (OSTI)

Currently, there are numerous indicators (single and composite) for measuring impacts in the three pillars, though current thinking emphasises the need for system thinking rather than the reductionist concept of pillars. Most existing indices/methods measure single aspects of sustainability and the more integrated indicators are aimed at national or global level assessments. A review of existing indicators, methods and models within the context of complex system sustainability showed that no single existing index, method or model was able to assess sustainability of complex systems. Most fail to account for complex system characteristics, such as system dynamics, interconnections and interdependencies of system components, a system's ability to learn and remember, emergence of novel behaviours, co-evolution, etc. This paper presents the methodology used to develop a new model for assessing sustainability of complex systems based on risk.

Gayathri Babarenda Gamage; Carol Boyle; Ron McDowall

2013-01-01T23:59:59.000Z

252

A viscoplasticity model with an enhanced control of the yield surface distortion  

E-Print Network (OSTI)

A new model of metal viscoplasticity, which takes combined isotropic, kinematic, and distortional hardening into account, is presented. The basic modeling assumptions are illustrated using a new two-dimensional rheological analogy. This demonstrative rheological model is used as a guideline for the construction of constitutive relations. The nonlinear kinematic hardening is captured using the well-known Armstrong-Frederick approach. The distortion of the yield surface is described with the help of a so-called distortional backstress. A distinctive feature of the model is that any smooth convex saturated form of the yield surface which is symmetric with respect to the loading direction can be captured. In particular, an arbitrary sharpening of the saturated yield locus in the loading direction combined with a flattening on the opposite side can be covered. Moreover, the yield locus evolves smoothly and its convexity is guaranteed at each hardening stage. A strict proof of the thermodynamic consistency is provi...

Shutov, A V

2012-01-01T23:59:59.000Z

253

Simulation of ultrasonic surface waves with multi-Gaussian and point source beam models  

SciTech Connect

In the past decade, multi-Gaussian beam models have been developed to solve many complicated bulk wave propagation problems. However, to date those models have not been extended to simulate the generation of Rayleigh waves. Here we will combine Gaussian beams with an explicit high frequency expression for the Rayleigh wave Green function to produce a three-dimensional multi-Gaussian beam model for the fields radiated from an angle beam transducer mounted on a solid wedge. Simulation results obtained with this model are compared to those of a point source model. It is shown that the multi-Gaussian surface wave beam model agrees well with the point source model while being computationally much more efficient.

Zhao, Xinyu [Center for NDE, Iowa State University, Ames, IA, 50011, USA and Dept. of Mechanical Eng., Beijing Institute of Technology, Beijing, 100081 (China); Schmerr, Lester W. Jr.; Li, Xiongbing [Center for NDE, Iowa State University, Ames, IA, 50011 (United States); Sedov, Alexander [Dept. of Mechanical Eng., Lakehead University, Thunder Bay, ON (Canada)

2014-02-18T23:59:59.000Z

254

Model calculation of anisotropic charge and magnetic moment distribution on a Ni(001) surface  

Science Journals Connector (OSTI)

Anisotropies in the electronic charge and moment distribution on a (001) surface of Ni are influenced by the kinetic and Coulomb energies as well as by exchange and correlations. By using a simple model Hamiltonian the various contributions are analyzed. In particular we consider the effects of nonlocal exchange and correlation energies on the anisotropies. When we simulate a local exchange and correlation approximation, we find a decrease in the surface anisotropies (e.g., a moment in the 3z2-r2 orbital). The accompanying relative energy changes are very small, i.e., of the order of 10-4. The same holds true for anisotropies in the exchange splittings. A comparison is attempted between the results of the present model and recent ab initio calculations for the Ni surface in which the local-spin-density approximation is applied.

A. M. Oles and P. Fulde

1984-10-15T23:59:59.000Z

255

Testing a Dynamical Model for Mid-Latitude Sea Surface Temperature Anomalies  

Science Journals Connector (OSTI)

A slab model of the oceanic mixed layer is used to predict the statistical characteristics of the sea surface temperature anomalies that are forced by day-to-day changes in air-sea fluxes in the presence of a mean current. Because of the short ...

Claude Frankignoul; Richard W. Reynolds

1983-07-01T23:59:59.000Z

256

SURFACE ELASTICITY MODELS FOR STATIC AND DYNAMIC RESPONSE OF NANOSCALE BEAMS  

E-Print Network (OSTI)

SURFACE ELASTICITY MODELS FOR STATIC AND DYNAMIC RESPONSE OF NANOSCALE BEAMS by Chang Liu B) THE UNIVERSITY OF BRITISH COLUMBIA (Vancouver) February 2010 © Chang Liu, 2010 #12;ii Abstract Nanoscale beam of nanoscale beams. The objective is to provide NEMS designers with an efficient set of tools that can predict

Phani, A. Srikantha

257

A COMPARISON BETWEEN GLOBAL SOLAR MAGNETOHYDRODYNAMIC AND POTENTIAL FIELD SOURCE SURFACE MODEL RESULTS  

E-Print Network (OSTI)

ABSTRACT The large-scale, steady-state magnetic field configuration of the solar corona is typicallyA COMPARISON BETWEEN GLOBAL SOLAR MAGNETOHYDRODYNAMIC AND POTENTIAL FIELD SOURCE SURFACE MODEL computer resources, and can resolve structure on scales beyond those that can be handled by current MHD

California at Berkeley, University of

258

Lattice gas model for CO electrooxidation on Pt-Ru bimetallic surfaces  

SciTech Connect

The authors propose a lattice gas model for the carbon monoxide oxidation on platinum-ruthenium electrode surfaces. The kinetic model includes the main mechanistic bifunctional features as they are generally agreed upon in the literature. The CO stripping voltammetry is solved by dynamic Monte Carlo simulations. For a randomly dispersed alloy of Ru and Pt, the model gives a satisfactory semiquantitative agreement with the experimental CO stripping results of Gasteiger et al. [Journal of Physical Chemistry 1994, 98, 617]. It is shown how the bifunctional mechanism cannot operate if CO is not mobile on the surface, and a simple Tafel-type experiment with a low concentration of active Pt-Ru sites is suggested to check quantitatively the Co mobility rate. On a surface with large Ru islands, the overpotential for CO oxidation increases, and two CO stripping peaks may appear if the CO mobility is sufficiently low. A mean-field model of the system reproduces the DMC results for high CO mobility but breaks down for a system with large Ru islands and a comparatively low CO surface diffusion constant.

Koper, M.T.M.; Jansen, A.P.J.; Santen, R.A. van [Schuit Inst. of Catalysis, Eindhoven (Netherlands). Lab. of Inorganic Chemistry and Catalysis] [Schuit Inst. of Catalysis, Eindhoven (Netherlands). Lab. of Inorganic Chemistry and Catalysis; Lukkien, J.J. [Eindhoven Univ. of Technology (Netherlands). Dept. of Mathematics and Computing Science] [Eindhoven Univ. of Technology (Netherlands). Dept. of Mathematics and Computing Science

1999-07-01T23:59:59.000Z

259

Control of surface gravity waves by variable fluid injection in a model of a copper  

E-Print Network (OSTI)

Control of surface gravity waves by variable fluid injection in a model of a copper converter splashing appears in copper converters when air is injected into the molten matte in order to carry out to the opposite extreme to where the nozzle injection is placed. Key words: Copper converter, gravity waves

Osses, Axel

260

The effect of soil hydraulic properties vs. soil texture in land surface models  

E-Print Network (OSTI)

. E. Small Department of Geology, University of Colorado, Boulder, Colorado, USA Received 26 October (SHPs) is not well known. This study focuses on the effect of SHP selection on modeled surface fluxes in a large SHP database. Within most STCs, the outputs have a range of 350 WmÃ?2 for latent and sensible heat

Small, Eric

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Surface Complexation Model for Strontium Sorption to Amorphous Silica and Goethite  

SciTech Connect

Strontium sorption to amorphous silica and goethite was measured as a function of pH and dissolved strontium and carbonate concentrations at 25 C. Strontium sorption gradually increases from 0 to 100% from pH 6 to 10 for both phases and requires multiple outer-sphere surface complexes to fit the data. All data are modeled using the triple layer model and the site-occupancy standard state; unless stated otherwise all strontium complexes are mononuclear. Strontium sorption to amorphous silica in the presence and absence of dissolved carbonate can be fit with tetradentate Sr{sup 2+} and SrOH{sup +} complexes on the {beta}-plane and a monodentate Sr{sup 2+} complex on the diffuse plane to account for strontium sorption at low ionic strength. Strontium sorption to goethite in the absence of dissolved carbonate can be fit with monodentate and tetradentate SrOH{sup +} complexes and a tetradentate binuclear Sr{sup 2+} species on the {beta}-plane. The binuclear complex is needed to account for enhanced sorption at high strontium surface loadings. In the presence of dissolved carbonate additional monodentate Sr{sup 2+} and SrOH{sup +} carbonate surface complexes on the {beta}-plane are needed to fit strontium sorption to goethite. Modeling strontium sorption as outer-sphere complexes is consistent with quantitative analysis of extended X-ray absorption fine structure (EXAFS) on selected sorption samples that show a single first shell of oxygen atoms around strontium indicating hydrated surface complexes at the amorphous silica and goethite surfaces. Strontium surface complexation equilibrium constants determined in this study combined with other alkaline earth surface complexation constants are used to recalibrate a predictive model based on Born solvation and crystal-chemistry theory. The model is accurate to about 0.7 log K units. More studies are needed to determine the dependence of alkaline earth sorption on ionic strength and dissolved carbonate and sulfate concentrations for the development of a robust surface complexation database to estimate alkaline earth sorption in the environment.

Carroll, S; Robers, S; Criscenti, L; O'Day, P

2007-11-30T23:59:59.000Z

262

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

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.

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

263

Assimilation of surface data in a one-dimensional physical-biogeochemical model of the surface ocean: 2. Adjusting a simple trophic model to chlorophyll, temperature, nitrate, and pCO{sub 2} data  

SciTech Connect

This paper builds on a previous work which produced a constrained physical-biogeochemical model of the carbon cycle in the surface ocean. Three issues are addressed: (1) the results of chlorophyll assimilation using a simpler trophic model, (2) adjustment of parameters using the simpler model and data other than surface chlorophyll concentrations, and (3) consistency of the main carbon fluxes derived by the simplified model with values from the more complex model. A one-dimensional vertical model coupling the physics of the ocean mixed layer and a description of biogeochemical processes with a simple trophic model was used to address these issues. Chlorophyll concentration, nitrate concentration, and temperature were used to constrain the model. The surface chlorophyll information was shown to be sufficient to constrain primary production within the photic layer. The simultaneous assimilation of chlorophyll, nitrate, and temperature resulted in a significant improvement of model simulation for the data used. Of the nine biological and physical parameters which resulted in significant variations of the simulated chlorophyll concentration, seven linear combinations of the mode parameters were constrained. The model fit was an improvement on independent surface chlorophyll and nitrate data. This work indicates that a relatively simple biological model is sufficient to describe carbon fluxes. Assimilation of satellite or climatological data coulc be used to adjust the parameters of the model for three-dimensional models. It also suggests that the main carbon fluxes driving the carbon cycle within surface waters could be derived regionally from surface information. 38 refs., 16 figs., 7 tabs.

Prunet, P.; Minster, J.F.; Echevin, V. [Laboratoire CNES-CNRS, Toulouse (France)] [and others] [Laboratoire CNES-CNRS, Toulouse (France); and others

1996-03-01T23:59:59.000Z

264

Low-temperature Swelling in LWR Internal Components: Current Data and Modeling Assessment  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

LTR-2012/390 LTR-2012/390 Low-temperature Swelling in LWR Internal Components: Current Data and Modeling Assessment R. E. Stoller, A. V. Barashev, and S. I. Golubov Materials Science and Technology Division Oak Ridge National Laboratory Prepared for: Light Water Reactor Sustainability Program Office of Nuclear Energy, Science and Technology U.S. Department of Energy September 2012 ORNL/LTR-2012/390 1 Low-temperature Swelling in LWR Internal Components: Current Data and Modeling Assessment Abstract Recent experimental observations have made it clear that cavity formation can occur in light-water reactor internal components fabricated from austenitic stainless during the course of their service life. In order to assess the potential for cavity swelling

265

Planetary boundary layer depth in Global climate models induced biases in surface climatology  

E-Print Network (OSTI)

The Earth has warmed in the last century with the most rapid warming occurring near the surface in the arctic. This enhanced surface warming in the Arctic is partly because the extra heat is trapped in a thin layer of air near the surface due to the persistent stable-stratification found in this region. The warming of the surface air due to the extra heat depends upon the amount of turbulent mixing in the atmosphere, which is described by the depth of the atmospheric boundary layer (ABL). In this way the depth of the ABL determines the effective response of the surface air temperature to perturbations in the climate forcing. The ABL depth can vary from tens of meters to a few kilometers which presents a challenge for global climate models which cannot resolve the shallower layers. Here we show that the uncertainties in the depth of the ABL can explain up to 60 percent of the difference between the simulated and observed surface air temperature trends and 50 percent of the difference in temperature variability...

Davy, Richard

2014-01-01T23:59:59.000Z

266

Accretion vs colliding wind models for the gamma-ray binary LS I +61 303: an assessment  

E-Print Network (OSTI)

LS I +61 303 is a puzzling Be/X-ray binary with variable gamma-ray emission at up TeV energies. The nature of the compact object and the origin of the high-energy emission are unclear. One family of models invokes particle acceleration in shocks from the collision between the B-star wind and a relativistic pulsar wind, while another centers on a relativistic jet powered by accretion. Recent high-resolution radio observations showing a putative "cometary tail" pointing away from the Be star near periastron have been cited as support for the pulsar-wind model. We wish here to carry out a quantitative assessment of these competing models for this extraordinary source. We apply a 3D SPH code for dynamical simulations of both the pulsar-wind-interaction and accretion-jet models. The former yields a description of the shape of the wind-wind interaction surface. The latter provides an estimation of the accretion rate. The results allow critical evaluation of how the two distinct models confront the data in various wavebands under a range of conditions. When one accounts for the 3D dynamical wind interaction under realistic constraints for the relative strength of the B-star and pulsar winds, the resulting form of the interaction front does not match the putative "cometary tail" claimed from radio observations. On the other hand, dynamical simulations of the accretion-jet model indicate that the orbital phase variation of accretion power includes a secondary broad peak well away from periastron, thus providing a plausible way to explain the observed TeV gamma ray emission toward apastron. We conclude that the colliding-wind model is not clearly established for LS I +61 303, while the accretion-jet model can reproduce many key characteristics of the observed TeV gamma-ray emission.

G. E. Romero; A. T. Okazaki; M. Orellana; S. P. Owocki

2007-06-09T23:59:59.000Z

267

Validation of a Cognitive Diagnostic Model Across Multiple Forms of a Reading Comprehension Assessment  

E-Print Network (OSTI)

VALIDATION OF A COGNITIVE DIAGNOSTIC MODEL ACROSS MULTIPLE FORMS OF A READING COMPREHENSION ASSESSMENT by Amy K. Clark Submitted to the graduate degree... program in the Department of Psychology and Research in Education and the Graduate Faculty of the University of Kansas in partial fulfillment of the requirements for the...

Clark, Amy K

2013-12-31T23:59:59.000Z

268

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

E-Print Network (OSTI)

July 15, 1999 #12;Abstract Much of the evidence for health e ects of particulate air pollution has come. We thus refer to the `air pollution hypothesis' to describe increased risk of health outcomes dueAssessing Seasonal Confounding and Model Selection Bias in Air Pollution Epidemiology Using

Washington at Seattle, University of

269

Ex-plant consequence assessment for NUREG-1150: Models, typical results, uncertainties  

SciTech Connect

The assessment of ex-plant consequences for NUREG-1150 source terms was performed using the MELCOR Accident Consequence Code System (MACCS). This paper will briefly discuss the following elements of MACCS consequence calculations: input data, phenomena modeled, computational framework, typical results, controlling phenomena, and uncertainties. Wherever possible, NUREG-1150 results will be used to illustrate the discussion. 28 refs., 14 figs., 6 tabs.

Sprung, J.L.

1987-01-01T23:59:59.000Z

270

Cognitive Assessment Models with Few Assumptions, and Connections with Nonparametric IRT  

E-Print Network (OSTI)

Cognitive Assessment Models with Few Assumptions, and Connections with Nonparametric IRT Brian of the monotonicity conditions discussed in Section 4. #12;Abstract In recent years, as cognitive theories of learning" on student achievement relative to theory-driven lists of examinee skills, beliefs and other cognitive

Junker, Brian

271

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

E-Print Network (OSTI)

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

Peterson, Robert K. D.

272

Uncertainty Analysis of the Adequacy Assessment Model of a Distributed Generation System  

E-Print Network (OSTI)

of evidence theory, the hybrid propagation approach is introduced. A demonstration is given on a DG system enables end-users to install renewable generators (e.g. solar generators and wind turbines) on1 Uncertainty Analysis of the Adequacy Assessment Model of a Distributed Generation System Yanfu Li

Paris-Sud XI, Université de

273

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

E-Print Network (OSTI)

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

Paris-Sud XI, Université de

274

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

SciTech Connect

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.

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

2014-01-01T23:59:59.000Z

275

Modeling of atmospheric-pressure plasma columns sustained by surface waves  

Science Journals Connector (OSTI)

A self-consistent two-dimensional fluid-plasma model coupled to Maxwell’s equations is presented for argon discharges sustained at atmospheric pressure by the propagation of an electromagnetic surface wave. The numerical simulation provides the full axial and radial structure of the surface-wave plasma column and the distribution of the electromagnetic fields for given discharge operating conditions. To describe the contraction phenomenon, a characteristic feature of high-pressure discharges, we consider the kinetics of argon molecular ions in the charged-particle balance. An original feature of the model is to take into account the gas flow by solving self-consistently the mass, momentum, and energy balance equations for neutral particles. Accounting for the gas flow explains reported discrepancies between measured and calculated plasma parameters when assuming the local axial uniformity approximation. In contrast to the low-pressure case, the latter approximation is shown to be of limited validity at atmospheric pressure. The gas temperature is found to be a key parameter in modeling surface-wave discharges sustained at atmospheric pressure. It determines the radial and the axial structure of the plasma column. The calculated plasma parameters and wave propagation characteristics using the present two-dimensional fluid model are in good agreement with our set of experimental data.

Y. Kabouzi; D. B. Graves; E. Castaños-Martínez; M. Moisan

2007-01-09T23:59:59.000Z

276

Theoretical model for methanol formation from CO and H/sub 2/ on zinc oxide surfaces  

SciTech Connect

Models are developed for the polar (0001) and nonpolar (1010) surfaces of ZnO in order to consider methanol formation from adsorbed carbon monoxide and hydrogen atoms. The heats of adsorption of H/sub x/CO and OH/sub x/CO (x = 0-3) species involved in methanol formation are computed to determine the enthalpy changes of reaction. Reaction sequences involving formyl or formate intermediates are considered. The reaction mechanism is catalyzed by the Cu/sup +/ to proceed through a methoxy intermediate on Cu/sup +//ZnO with a lower of the energy pathway. The ZnO surfaces are poor donors and function primarily as acceptors of electron density from CO. The donor role of Cu/sup +/ is demonstrated on the polar surface by increasing the heat of adsorption of acceptor adspecies and decreasing the heat of adsorption of donor adspecies. 22 references, 8 figures, 4 tables.

Baetzold, R.C.

1985-09-12T23:59:59.000Z

277

Biosphere Modeling and Analyses in Support of Total System Performance Assessment  

SciTech Connect

The Nuclear Waste Policy Act of 1982 established the obligations of and the relationship between the U.S. Environmental Protection Agency (EPA), the U.S. Nuclear Regulatory Commission (NRC), and the U.S. Department of Energy (DOE) for the management and disposal of high-level radioactive wastes. In 1985, the EPA promulgated regulations that included a definition of performance assessment that did not consider potential dose to a member of the general public. This definition would influence the scope of activities conducted by DOE in support of the total system performance assessment program until 1995. The release of a National Academy of Sciences (NAS) report on the technical basis for a Yucca Mountain-specific standard provided the impetus for the DOE to initiate activities that would consider the attributes of the biosphere, i.e. that portion of the earth where living things, including man, exist and interact with the environment around them. The evolution of NRC and EPA Yucca Mountain-specific regulations, originally proposed in 1999, was critical to the development and integration of biosphere modeling and analyses into the total system performance assessment program. These proposed regulations initially differed in the conceptual representation of the receptor of interest to be considered in assessing performance. The publication in 2001 of final regulations in which the NRC adopted standard will permit the continued improvement and refinement of biosphere modeling and analyses activities in support of assessment activities.

Jeff Tappen; M.A. Wasiolek; D.W. Wu; J.F. Schmitt

2001-12-06T23:59:59.000Z

278

Biosphere Modeling and Analyses in Support of Total System Performance Assessment  

SciTech Connect

The Nuclear Waste Policy Act of 1982 established the obligations of and the relationship between the U.S. Environmental Protection Agency (EPA), the U.S. Nuclear Regulatory Commission (NRC), and the U.S. Department of Energy (DOE) for the management and disposal of high-level radioactive wastes. In 1985, the EPA promulgated regulations that included a definition of performance assessment that did not consider potential dose to a member of the general public. This definition would influence the scope of activities conducted by DOE in support of the total system performance assessment program until 1995. The release of a National Academy of Sciences (NAS) report on the technical basis for a Yucca Mountain-specific standard provided the impetus for the DOE to initiate activities that would consider the attributes of the biosphere, i.e. that portion of the earth where living things, including man, exist and interact with the environment around them. The evolution of NRC and EPA Yucca Mountain-specific regulations, originally proposed in 1999, was critical to the development and integration of biosphere modeling and analyses into the total system performance assessment program. These proposed regulations initially differed in the conceptual representation of the receptor of interest to be considered in assessing performance. The publication in 2001 of final regulations in which the NRC adopted standard will permit the continued improvement and refinement of biosphere modeling and analyses activities in support of assessment activities.

Tappen, J. J.; Wasiolek, M. A.; Wu, D. W.; Schmitt, J. F.; Smith, A. J.

2002-02-26T23:59:59.000Z

279

Assessing Impacts of Climate Change on Forests: The State of Biological Modeling  

DOE R&D Accomplishments (OSTI)

Models that address the impacts to forests of climate change are reviewed by four levels of biological organization: global, regional or landscape, community, and tree. The models are compared as to their ability to assess changes in greenhouse gas flux, land use, maps of forest type or species composition, forest resource productivity, forest health, biodiversity, and wildlife habitat. No one model can address all of these impacts, but landscape transition models and regional vegetation and land-use models consider the largest number of impacts. Developing landscape vegetation dynamics models of functional groups is suggested as a means to integrate the theory of both landscape ecology and individual tree responses to climate change. Risk assessment methodologies can be adapted to deal with the impacts of climate change at various spatial and temporal scales. Four areas of research development are identified: (1) linking socioeconomic and ecologic models, (2) interfacing forest models at different scales, (3) obtaining data on susceptibility of trees and forest to changes in climate and disturbance regimes, and (4) relating information from different scales.

Dale, V. H.; Rauscher, H. M.

1993-04-06T23:59:59.000Z

280

Monomer-dimer reaction model with asymmetric adsorption of monomer and dimer on the catalyst surface  

Science Journals Connector (OSTI)

The irreversible kinetics of the Ziff-Gulari-Barshad model in the presence of inhomogeneity on a catalyst surface is investigated by means of Monte Carlo simulation. We assume that only part of catalyst surface sites are active for surface catalytic reaction and randomly distributed on the catalyst surface. The adsorption of a O2 molecule is permitted if one site of a nearest-neighbor vacant pair is active. CO can adsorb on all vacant sites, but the adsorption probability is p(p<1) if the site is not active. In our modified model, the O-passivated phase disappears and the continuous phase transition between the O passivated and the reactive state is eliminated. We also find that the transition between the CO passivated and the reactive state is continuous if the concentration of the active sites is small, and it becomes discontinuous with increasing concentrations of active sites. Furthermore, it is shown that a hysteresis loop exists whether the CO-passivated transition is continuous or discontinuous. Our simulation results are in good agreement with many relevant experimental results and may provide an alternative explanation for the experimental observations.

Da-yin Hua and Yu-qiang Ma

2001-10-17T23:59:59.000Z

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

A stochastic penetration rate model for rotary drilling in surface mines  

Science Journals Connector (OSTI)

Abstract Principal Component Analysis (PCA) is used to determine the most effective parameters on the rock mass penetrability by considering their variance ratio in the first principal component. A model is developed for the prediction of rotary drills penetration rate using non-linear multiple regression analysis. Distribution functions for the effective parameters are calculated using measured data from two case studies. Applying the developed penetration rate model, a stochastic analysis is carried out using the Monte Carlo simulation. The proposed method provides a simple and effective assessment of the variability of the penetration rate model and its dependent parameters. Results showed that the PCA and Monte Carlo are suitable techniques for modeling and assessing the variability of rock mass penetrability parameters. According to the developed distribution model, with 90% of confidence level the penetration rate values range 0.2–2.5 m/min, which shows the wide possible range of penetration rates for rotary drilling especially in sedimentary (limestone and sandstone bearing magnetite mineral of Golgohar mine) and Sarcheshmeh igneous porphyry rock masses.

Omid Saeidi; Seyed Rahman Torabi; Mohammad Ataei; Jamal Rostami

2014-01-01T23:59:59.000Z

282

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

E-Print Network (OSTI)

). 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...

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

283

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

E-Print Network (OSTI)

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.

A. I. Ivanytskyi

2011-04-11T23:59:59.000Z

284

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

SciTech Connect

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.

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

285

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

SciTech Connect

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.

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

286

Assessing Surface Solar Irradiance From ISCCP-B2 Data Sets Lefvre M., Diabat L., Wald L., Using reduced data sets ISCCP-B2 from the Meteosat satellites to  

E-Print Network (OSTI)

to assess the daily mean of the surface solar irradiance at any geographical site in Europe and Africa-00363664,version1-24Feb2009 Author manuscript, published in "Solar Energy 81 (2007) 240-253" DOI : 10Assessing Surface Solar Irradiance From ISCCP-B2 Data Sets Lefèvre M., Diabaté L., Wald L., Using

Paris-Sud XI, Université de

287

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

E-Print Network (OSTI)

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

Victoria, University of

288

A viscoplasticity model with an enhanced control of the yield surface distortion  

E-Print Network (OSTI)

A new model of metal viscoplasticity, which takes combined isotropic, kinematic, and distortional hardening into account, is presented. The basic modeling assumptions are illustrated using a new two-dimensional rheological analogy. This demonstrative rheological model is used as a guideline for the construction of constitutive relations. The nonlinear kinematic hardening is captured using the well-known Armstrong-Frederick approach. The distortion of the yield surface is described with the help of a so-called distortional backstress. A distinctive feature of the model is that any smooth convex saturated form of the yield surface which is symmetric with respect to the loading direction can be captured. In particular, an arbitrary sharpening of the saturated yield locus in the loading direction combined with a flattening on the opposite side can be covered. Moreover, the yield locus evolves smoothly and its convexity is guaranteed at each hardening stage. A strict proof of the thermodynamic consistency is provided. Finally, the predictive capabilities of the material model are verified using the experimental data for a very high work hardening annealed aluminum alloy 1100 Al.

A. V. Shutov; J. Ihlemann

2012-03-31T23:59:59.000Z

289

A new analytic-adaptive model for EGS assessment, development and  

Open Energy Info (EERE)

new analytic-adaptive model for EGS assessment, development and new analytic-adaptive model for EGS assessment, development and management support Geothermal Project Jump to: navigation, search Last modified on July 22, 2011. Project Title A new analytic-adaptive model for EGS assessment, development and management support Project Type / Topic 1 Recovery Act: Enhanced Geothermal Systems Component Research and Development/Analysis Project Type / Topic 2 Integrated Chemical, Thermal, Mechanical and Hydrological Modeling Project Description The University of Nevada - Reno (UNR), proposes to develop a new, integrated solution technique for simulating the Thermal, Hydrological, Mechanical, and Chemical (THMC) processes relevant to thermal energy extraction from an Enhanced Geothermal System (EGS). UNR defines the great challenges in numerical modeling as to (1) dealing with flows and transport in the stimulated fractures of the EGS of largely unknown geometry and characteristics; and (2) discovering the best possible cooling fluid circulation solution in the EGS by trial-and-error numerical simulations. The new THMC will have an adaptive, Computational Fluid Dynamics (CFD) component, integrated with the THMC rockmass model in order to match field test signatures, or desired outcomes in design hypothesis test. The project's main hypothesis is that there are new solutions to heat extraction from an as-created, enhanced fracture system of EGS. The project will develop a new THMC simulation model with new capabilities and prove the main hypothesis by and applying it to various EGS designs including emerging concepts, two-phase (steam-gas-liquid) coolant flows in the fracture network, and dynamic, huff-puff operations.

290

Assessing the solvent-dependent surface area of unfolded proteins using an ensemble model  

Science Journals Connector (OSTI)

...J Mol Biol 353 : 873 – 887 . 25 Pappu RV Srinivasan R Rose GD ( 2000 ) The Flory isolated-pair...Crick SL Jayaraman M Frieden C Wetzel R Pappu RV ( 2006 ) Fluorescence correlation...1749 . 49 Schweitzer-Stenner R Measey TJ ( 2007 ) The alanine-rich XAO...

Haipeng Gong; George D. Rose

2008-01-01T23:59:59.000Z

291

Fuzzy integrated vulnerability assessment model for critical facilities in combating the terrorism  

Science Journals Connector (OSTI)

Critical facility vulnerability assessment is a highly complex strategic activity in combating the terrorism and necessitates a structured quantified methodology to support the decision-making process in defense planning. In the system perspective, the critical facility, such as airport, dam, governmental facility, harbor, nuclear power plant, oil plant etc., can be defined as a system that relies on a group of different interdependent logical and physical entities as system functions and system components. The aim of this paper is to present a realistic approach to determine the vulnerability of such a system defended against the terrorist attack under multiple criteria which can be both qualitative and quantitative by considering these interdependencies. The proposed approach, called fuzzy integrated vulnerability assessment model (FIVAM), is based on fuzzy set theory, Simple Multi-Attribute Rating Technique (SMART) and Fuzzy Cognitive Maps (FCM) methodology in a group decision-making environment. The FIVAM approach is presented step-by-step and applied to a simple case study on airport vulnerability assessment. The results of the application are compared to those observed through a classical vulnerability assessment model to illustrate the effectiveness of the FIVAM. Furthermore, FIVAM provides a framework to identify the hidden vulnerabilities caused by the functional interdependencies within the system. The results also show that FIVAM quantifies the vulnerability of the system, system functions and system components, and determines the most critical functions and components by simulating the system behavior.

Ilker Akgun; Ahmet Kandakoglu; Ahmet Fahri Ozok

2010-01-01T23:59:59.000Z

292

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

E-Print Network (OSTI)

to the appreciation that the eruptions may continue for 282 decades and should be regarded as a “chronic” problem for planning purposes (Donovan and 283 Oppenheimer, 2014). Managing this transition has required consistent yet innovative 284 approaches to scientific... to their advice. 524 There is abundant evidence of the political challenges of risk assessment and management on 525 Montserrat, and the complex boundaries and connectivities involved (Aspinall et al., 2002; 526 Haynes et al., 2007; Donovan and Oppenheimer...

Donovan, Amy R.; Oppenheimer, Clive

2014-11-27T23:59:59.000Z

293

Development of a Composite Non-Electrostatic Surface Complexation Model Describing Plutonium Sorption to Aluminosilicates  

SciTech Connect

Due to their ubiquity in nature and chemical reactivity, aluminosilicate minerals play an important role in retarding actinide subsurface migration. However, very few studies have examined Pu interaction with clay minerals in sufficient detail to produce a credible mechanistic model of its behavior. In this work, Pu(IV) and Pu(V) interactions with silica, gibbsite (Aloxide), and Na-montmorillonite (smectite clay) were examined as a function of time and pH. Sorption of Pu(IV) and Pu(V) to gibbsite and silica increased with pH (4 to 10). The Pu(V) sorption edge shifted to lower pH values over time and approached that of Pu(IV). This behavior is apparently due to surface mediated reduction of Pu(V) to Pu(IV). Surface complexation constants describing Pu(IV)/Pu(V) sorption to aluminol and silanol groups were developed from the silica and gibbsite sorption experiments and applied to the montmorillonite dataset. The model provided an acceptable fit to the montmorillonite sorption data for Pu(V). In order to accurately predict Pu(IV) sorption to montmorillonite, the model required inclusion of ion exchange. The objective of this work is to measure the sorption of Pu(IV) and Pu(V) to silica, gibbsite, and smectite (montmorillonite). Aluminosilicate minerals are ubiquitous at the Nevada National Security Site and improving our understanding of Pu sorption to aluminosilicates (smectite clays in particular) is essential to the accurate prediction of Pu transport rates. These data will improve the mechanistic approach for modeling the hydrologic source term (HST) and provide sorption Kd parameters for use in CAU models. In both alluvium and tuff, aluminosilicates have been found to play a dominant role in the radionuclide retardation because their abundance is typically more than an order of magnitude greater than other potential sorbing minerals such as iron and manganese oxides (e.g. Vaniman et al., 1996). The sorption database used in recent HST models (Carle et al., 2006) and upscaled for use in CAU models (Stoller-Navarro, 2008) includes surface complexation constants for U, Am, Eu, Np and Pu (Zavarin and Bruton, 2004). Generally, between 15 to 30 datasets were used to develop the constants for each radionuclide. However, the constants that describe Pu sorption to aluminosilicates were developed using only 10 datasets, most of which did not specify the oxidation state of Pu in the experiment. Without knowledge or control of the Pu oxidation state, a high degree of uncertainty is introduced into the model. The existing Pu surface complexation model (e.g. Zavarin and Bruton, 2004) drastically underestimates Pu sorption and, thus, will overestimate Pu migration rates (Turner, 1995). Recent HST simulations at Cambric (Carle et al., 2006) suggest that the existing surface complexation model may underpredict Pu K{sub d}s by as much as 3 orders of magnitude. In order to improve HST and CAU-scale transport models (and, as a result, reduce the conservative nature Pu migration estimates), sorption experiments were performed over a range of solution conditions that brackets the groundwater chemistry of the Nevada National Security Site. The aluminosilicates examined were gibbsite, silica, and montmorillonite.

Powell, B A; Kersting, A; Zavarin, M; Zhao, P

2008-10-28T23:59:59.000Z

294

Optimization of Switched Reluctance Motor for Efficiency Improvement Using Response Surface Model and Kriging Model  

Science Journals Connector (OSTI)

This paper presented an optimization of switched reluctance motor for higher efficiency. The motor in this study was designed based on the magnetic energy conversion loop according to the power requirements of application system. It's found that besides ... Keywords: switched reluctance motor, optimziation, RSM, Kriging Model

Xueguan Song; Youngchul Park; Jian Li; Joonho Lee

2011-04-01T23:59:59.000Z

295

Dispersion models and air quality data for population exposure assessment to air pollution  

Science Journals Connector (OSTI)

Evaluating the extent of exposure to chemicals in absence of continuous measurements of their concentration in air and direct measures of personal exposure is crucial for epidemiological studies. Dispersion models can be a useful tool for reproducing spatio-temporal distribution of contaminants emitted by a specific source. However, they cannot easily be applied to short-term epidemiological studies because they require precise information on daily emission scenarios for a long time, which are generally not available. The aim of this study was to better assess the exposure in the industrial area of Brindisi, which suffers from various critical epidemiological situations, by integrating air pollution concentration data, emissions and model simulations concerning a specific point source. The results suggest that in the absence of direct exposure data and detailed information on specific pollutants associated to an emission, population exposure may be better assessed by taking into account proxy pollutants and the wind (direction and speed) as a potential health effects modifier.

Cristina Mangia; Marco Cervino; Emilio Antonio Luca Gianicolo

2014-01-01T23:59:59.000Z

296

Surface premelting  

Science Journals Connector (OSTI)

The most important results obtained in the theory of surface premelting of crystals are briefly discussed on the basis of the vibration-positional model, the quasiliquid layer model, the surface roughness model, and in the case of ice, the model of the oriented dipoles at the surface. A review of the existing experimental results on surface premelting is presented, these results being obtained by investigating the crystal morphology, the polar diagram of the specific surface energy, the surface self-diffusion, the thermal emissivity, as well as upon application of LEED, NMR, Rutherford backscattering at proton channeling and ellipsometry. The agreement between theoretical and experimental data is discussed.

D. Nenow

1984-01-01T23:59:59.000Z

297

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

Energy.gov (U.S. Department of Energy (DOE))

Report that assesses possible interference to various kinds of equipment operating in the marine environment where offshore wind farms could be installed.

298

A multi-model assessment of pollution transport to the Arctic  

SciTech Connect

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.

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

299

Estimation of the solubility parameters of model plant surfaces and agrochemicals: a valuable tool for understanding plant surface interactions  

Science Journals Connector (OSTI)

Most aerial plant parts are covered with a hydrophobic lipid-rich cuticle, which is the interface between the plant organs and the surrounding environment. Plant surfaces may have a high degree of hydrophobicity ...

Mohamed Khayet; Victoria Fernández

2012-11-01T23:59:59.000Z

300

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

SciTech Connect

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 ).

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

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

CORONAL HEATING BY SURFACE ALFVEN WAVE DAMPING: IMPLEMENTATION IN A GLOBAL MAGNETOHYDRODYNAMICS MODEL OF THE SOLAR WIND  

SciTech Connect

The heating and acceleration of the solar wind is an active area of research. Alfven waves, because of their ability to accelerate and heat the plasma, are a likely candidate in both processes. Many models have explored wave dissipation mechanisms which act either in closed or open magnetic field regions. In this work, we emphasize the boundary between these regions, drawing on observations which indicate unique heating is present there. We utilize a new solar corona component of the Space Weather Modeling Framework, in which Alfven wave energy transport is self-consistently coupled to the magnetohydrodynamic equations. In this solar wind model, the wave pressure gradient accelerates and wave dissipation heats the plasma. Kolmogorov-like wave dissipation as expressed by Hollweg along open magnetic field lines was presented in van der Holst et al. Here, we introduce an additional dissipation mechanism: surface Alfven wave (SAW) damping, which occurs in regions with transverse (with respect to the magnetic field) gradients in the local Alfven speed. For solar minimum conditions, we find that SAW dissipation is weak in the polar regions (where Hollweg dissipation is strong), and strong in subpolar latitudes and the boundaries of open and closed magnetic fields (where Hollweg dissipation is weak). We show that SAW damping reproduces regions of enhanced temperature at the boundaries of open and closed magnetic fields seen in tomographic reconstructions in the low corona. Also, we argue that Ulysses data in the heliosphere show enhanced temperatures at the boundaries of fast and slow solar wind, which is reproduced by SAW dissipation. Therefore, the model's temperature distribution shows best agreement with these observations when both dissipation mechanisms are considered. Lastly, we use observational constraints of shock formation in the low corona to assess the Alfven speed profile in the model. We find that, compared to a polytropic solar wind model, the wave-driven model with physical dissipation mechanisms presented in this work is more aligned with an empirical Alfven speed profile. Therefore, a wave-driven model which includes the effects of SAW damping is a better background to simulate coronal-mass-ejection-driven shocks.

Evans, R. M. [NASA Goddard Space Flight Center, Space Weather Lab, Greenbelt, MD 20771 (United States); Opher, M. [Astronomy Department, Boston University, 675 Commonwealth Avenue, Boston, MA 02215 (United States); Oran, R.; Van der Holst, B.; Sokolov, I. V.; Frazin, R.; Gombosi, T. I. [Center for Space Environment Modeling, University of Michigan, 2455 Hayward Street, Ann Arbor, MI 48109 (United States); Vasquez, A., E-mail: Rebekah.e.frolov@nasa.gov [Instituto de Astronomia y Fisica del Espacio (CONICET-UBA) and FCEN (UBA), CC 67, Suc 28, Ciudad de Buenos Aires (Argentina)

2012-09-10T23:59:59.000Z

302

An application of probabilistic safety assessment methods to model aircraft systems and accidents  

SciTech Connect

A case study modeling the thrust reverser system (TRS) in the context of the fatal accident of a Boeing 767 is presented to illustrate the application of Probabilistic Safety Assessment methods. A simplified risk model consisting of an event tree with supporting fault trees was developed to represent the progression of the accident, taking into account the interaction between the TRS and the operating crew during the accident, and the findings of the accident investigation. A feasible sequence of events leading to the fatal accident was identified. Several insights about the TRS and the accident were obtained by applying PSA methods. Changes proposed for the TRS also are discussed.

Martinez-Guridi, G.; Hall, R.E.; Fullwood, R.R.

1998-08-01T23:59:59.000Z

303

Evaporation model for beam based additive manufacturing using free surface lattice Boltzmann methods  

Science Journals Connector (OSTI)

Evaporation plays an important role in many technical applications including beam-based additive manufacturing processes, such as selective electron beam or selective laser melting (SEBM/SLM). In this paper, we describe an evaporation model which we employ within the framework of a two-dimensional free surface lattice Boltzmann method. With this method, we solve the hydrodynamics as well as thermodynamics of the molten material taking into account the mass and energy losses due to evaporation and the recoil pressure acting on the melt pool. Validation of the numerical model is performed by measuring maximum melt depths and evaporative losses in samples of pure titanium and Ti–6Al–4V molten by an electron beam. Finally, the model is applied to create processing maps for an SEBM process. The results predict that the penetration depth of the electron beam, which is a function of the acceleration voltage, has a significant influence on evaporation effects.

Alexander Klassen; Thorsten Scharowsky; Carolin Körner

2014-01-01T23:59:59.000Z

304

Development of Simplified Probabilistic Risk Assessment Model for Seismic Initiating Event  

SciTech Connect

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).

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

2012-06-01T23:59:59.000Z

305

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

SciTech Connect

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.

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

2004-06-25T23:59:59.000Z

306

Estimating surface water risk at Oak Ridge National Laboratory: Effects of site conditions on modeling results  

SciTech Connect

Multiple source term and groundwater modeling runs were executed to estimate surface water {sup 90}Sr concentrations resulting from leaching of sludges in five 180,000 gallon Gunite{trademark} tanks at Oak Ridge National Laboratory. Four release scenarios were analyzed: (1) leaching of unstabilized sludge with immediate tank failure; (2) leaching of unstabilized sludge with delayed tank failure due to chemical degradation; (3) leaching of stabilized sludge with immediate tank failure; and (4) leaching of residual contamination out of the shells of empty tanks. Source terms and concentrations of {sup 90}Sr in the stream directly downgradient of the tanks were calculated under these release scenarios. The following conclusions were drawn from the results of the modeling: (1) small changes in soil path length resulted in relatively large changes in the modeled {sup 90}Sr concentrations in the stream; (2) there was a linear relationship between the amount of sludge remaining in a tank and the peak concentration of {sup 90}Sr in the stream; (3) there was a linear relationship between the cumulative {sup 90}Sr release from a tank and the peak concentration of {sup 90}Sr in the stream; (4) sludge stabilization resulted in significantly reduced peak concentrations of {sup 90}Sr in the stream; and (5) although radioactive decay of {sup 90}Sr during the period of tank degradation resulted in incrementally lower peak {sup 90}Sr concentrations in surface water than under the immediate tank failure scenarios these concentrations were equivalent under the two scenarios after about 90 years.

Curtis, A.H. III

1996-08-01T23:59:59.000Z

307

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

SciTech Connect

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.

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

308

Simulating Surface Energy Fluxes and Radiometric Surface Temperatures for Two Arid Vegetation Communities Using the SHAW Model  

Science Journals Connector (OSTI)

While land–atmosphere transfer models have been pursued for over 30 years, Soil–Vegetation–Atmosphere–Transfer (SVAT) models are gaining attention only recently as the need to better represent the interaction between the soil and atmosphere in ...

G. N. Flerchinger; W. P. Kustas; M. A. Weltz

1998-05-01T23:59:59.000Z

309

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

SciTech Connect

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.

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

2004-12-02T23:59:59.000Z

310

Assimilation of surface data in a one-dimensional physical-biogeochemical model of the surface ocean: 1. Method and preliminary results  

SciTech Connect

This paper describes a method to estimate parameters of complex ocean carbon cycle models and to estimate carbon fluxes other than primary production from satellite data. A one-dimensional vertical model, which couples the physics of the ocean mixed layer and biogeochemical processes, was used to simulate the carbon cycle. Variational assimilation was applied to globally adjust the model solution. Consistent results were found for the grazing rate, the phytoplankton mortality rate, and the minimum concentration of zooplankton in winter. Some carbon fluxes appeared to be robustly constrained; however, primary production is apparently underestimated. The study results suggest that a simplified biological model would adequately the seasonal evolution of surface chlorophyll concentration, and would be more adapted to transform satellite data into carbon fluxes. Analysis of model behavior during assimilation experiments also provided information for other possible simplifications of the trophic model. 49 refs., 17 figs., 5 tabs.

Prunet, P.; Minster, J.F. [Laboratoire CNES-CNRS, Toulouse (France)] [Laboratoire CNES-CNRS, Toulouse (France); Ruiz-Pino, D. [Universite Pierre et Marie Curie, Paris (France)] [Universite Pierre et Marie Curie, Paris (France)

1996-03-01T23:59:59.000Z

311

Evaluation of a Conjunctive Surface–Subsurface Process Model (CSSP) over the Contiguous United States at Regional–Local Scales  

Science Journals Connector (OSTI)

This study presents a comprehensive evaluation on a Conjunctive Surface–Subsurface Process Model (CSSP) in predicting soil temperature–moisture distributions, terrestrial hydrology variations, and land–atmosphere exchanges against various in situ ...

Xing Yuan; Xin-Zhong Liang

2011-08-01T23:59:59.000Z

312

Coordinated formation pattern control of multiple marine surface vehicles with model uncertainty and time-varying ocean currents  

Science Journals Connector (OSTI)

This paper considers the coordinated formation pattern control of multiple marine surface vehicles in the presence of model uncertainty and time-varying ocean disturbances induced wind, waves and ocean currents. ...

Zhouhua Peng; Dan Wang; Hao Wang; Wei Wang

2014-12-01T23:59:59.000Z

313

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

E-Print Network (OSTI)

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 ...

Flores, Alejandro N.

314

Urban Energy Balance Obtained from the Comprehensive Outdoor Scale Model Experiment. Part I: Basic Features of the Surface Energy Balance  

Science Journals Connector (OSTI)

The objective of this study is to examine the basic features of the surface energy balance (SEB) using the data obtained from the Comprehensive Outdoor Scale Model (COSMO). COSMO is an idealized miniature city that has no vegetation, no human ...

Toru Kawai; Manabu Kanda

2010-07-01T23:59:59.000Z

315

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

SciTech Connect

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.

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

316

Pulmonary lobe segmentation based on ridge surface sampling and shape model fitting  

SciTech Connect

Purpose: Performing lobe-based quantitative analysis of the lung in computed tomography (CT) scans can assist in efforts to better characterize complex diseases such as chronic obstructive pulmonary disease (COPD). While airways and vessels can help to indicate the location of lobe boundaries, segmentations of these structures are not always available, so methods to define the lobes in the absence of these structures are desirable. Methods: The authors present a fully automatic lung lobe segmentation algorithm that is effective in volumetric inspiratory and expiratory computed tomography (CT) datasets. The authors rely on ridge surface image features indicating fissure locations and a novel approach to modeling shape variation in the surfaces defining the lobe boundaries. The authors employ a particle system that efficiently samples ridge surfaces in the image domain and provides a set of candidate fissure locations based on the Hessian matrix. Following this, lobe boundary shape models generated from principal component analysis (PCA) are fit to the particles data to discriminate between fissure and nonfissure candidates. The resulting set of particle points are used to fit thin plate spline (TPS) interpolating surfaces to form the final boundaries between the lung lobes. Results: The authors tested algorithm performance on 50 inspiratory and 50 expiratory CT scans taken from the COPDGene study. Results indicate that the authors' algorithm performs comparably to pulmonologist-generated lung lobe segmentations and can produce good results in cases with accessory fissures, incomplete fissures, advanced emphysema, and low dose acquisition protocols. Dice scores indicate that only 29 out of 500 (5.85%) lobes showed Dice scores lower than 0.9. Two different approaches for evaluating lobe boundary surface discrepancies were applied and indicate that algorithm boundary identification is most accurate in the vicinity of fissures detectable on CT. Conclusions: The proposed algorithm is effective for lung lobe segmentation in absence of auxiliary structures such as vessels and airways. The most challenging cases are those with mostly incomplete, absent, or near-absent fissures and in cases with poorly revealed fissures due to high image noise. However, the authors observe good performance even in the majority of these cases.

Ross, James C., E-mail: jross@bwh.harvard.edu [Channing Laboratory, Brigham and Women's Hospital, Boston, Massachusetts 02215 (United States); Surgical Planning Lab, Brigham and Women's Hospital, Boston, Massachusetts 02215 (United States); Laboratory of Mathematics in Imaging, Brigham and Women's Hospital, Boston, Massachusetts 02126 (United States); Kindlmann, Gordon L. [Computer Science Department and Computation Institute, University of Chicago, Chicago, Illinois 60637 (United States)] [Computer Science Department and Computation Institute, University of Chicago, Chicago, Illinois 60637 (United States); Okajima, Yuka; Hatabu, Hiroto [Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts 02215 (United States)] [Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts 02215 (United States); Díaz, Alejandro A. [Pulmonary and Critical Care Division, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02215 and Department of Pulmonary Diseases, Pontificia Universidad Católica de Chile, Santiago (Chile)] [Pulmonary and Critical Care Division, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02215 and Department of Pulmonary Diseases, Pontificia Universidad Católica de Chile, Santiago (Chile); Silverman, Edwin K. [Channing Laboratory, Brigham and Women's Hospital, Boston, Massachusetts 02215 and Pulmonary and Critical Care Division, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02215 (United States)] [Channing Laboratory, Brigham and Women's Hospital, Boston, Massachusetts 02215 and Pulmonary and Critical Care Division, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02215 (United States); Washko, George R. [Pulmonary and Critical Care Division, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02215 (United States)] [Pulmonary and Critical Care Division, Brigham and Women's Hospital and Harvard Medical School, Boston, Massachusetts 02215 (United States); Dy, Jennifer [ECE Department, Northeastern University, Boston, Massachusetts 02115 (United States)] [ECE Department, Northeastern University, Boston, Massachusetts 02115 (United States); Estépar, Raúl San José [Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts 02215 (United States) [Department of Radiology, Brigham and Women's Hospital, Boston, Massachusetts 02215 (United States); Surgical Planning Lab, Brigham and Women's Hospital, Boston, Massachusetts 02215 (United States); Laboratory of Mathematics in Imaging, Brigham and Women's Hospital, Boston, Massachusetts 02126 (United States)

2013-12-15T23:59:59.000Z

317

Modelling of c-C2H4O formation on grain surfaces  

E-Print Network (OSTI)

Despite its potential reactivity due to ring strain, ethylene oxide (c-C2H4O) is a complex molecule that seems to be stable under the physical conditions of an interstellar dense core; indeed it has been detected towards several high-mass star forming regions with a column density of the order of 10e13cm-2 (Ikeda et al. 2001). To date, its observational abundances cannot be reproduced by chemical models and this may be due to the significant contribution played by its chemistry on grain surfaces. Recently, Ward and Price (2011) have performed experiments in order to investigate the surface formation of ethylene oxide starting with oxygen atoms and ethylene ice as reactants. We present a chemical model which includes the most recent experimental results from Ward and Price (2011) on the formation of c-C2H4O. We study the influence of the physical parameters of dense cores on the abundances of c-C2H4O. We verify that ethylene oxide can indeed be formed during the cold phase (when the ISM dense cores are formed)...

Occhiogrosso, A; Ward, M D; Price, S D

2012-01-01T23:59:59.000Z

318

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

SciTech Connect

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.

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

2004-07-01T23:59:59.000Z

319

The microenvironmental modelling approach to assess children's exposure to air pollution – A review  

Science Journals Connector (OSTI)

Abstract Exposures to a wide spectrum of air pollutants were associated to several effects on children's health. Exposure assessment can be used to establish where and how air pollutants' exposures occur. However, a realistic estimation of children's exposures to air pollution is usually a great ethics challenge, especially for young children, because they cannot intentionally be exposed to contaminants and according to Helsinki declaration, they are not old enough to make a decision on their participation. Additionally, using adult surrogates introduces bias, since time–space–activity patterns are different from those of children. From all the different available approaches for exposure assessment, the microenvironmental (ME) modelling (indirect approach, where personal exposures are estimated or predicted from microenvironment measurements combined with time–activity data) seemed to be the best to assess children's exposure to air pollution as it takes into account the varying levels of pollution to which an individual is exposed during the course of the day, it is faster and less expensive. Thus, this review aimed to explore the use of the ME modelling approach methodology to assess children's exposure to air pollution. To meet this goal, a total of 152 articles, published since 2002, were identified and titles and abstracts were scanned for relevance. After exclusions, 26 articles were fully reviewed and main characteristics were detailed, namely: (i) study design and outcomes, including location, study population, calendar time, pollutants analysed and purpose; and (ii) data collection, including time–activity patterns (methods of collection, record time and key elements) and pollution measurements (microenvironments, methods of collection and duration and time resolution). The reviewed studies were from different parts of the world, confirming the worldwide application, and mostly cross-sectional. Longitudinal studies were also found enhancing the applicability of this approach. The application of this methodology on children is different from that on adults because of data collection, namely the methods used for collecting time–activity patterns must be different and the time–activity patterns are itself different, which leads to select different microenvironments to the data collection of pollutants' concentrations. The most used methods to gather information on time–activity patterns were questionnaires and diaries, and the main microenvironments considered were home and school (indoors and outdoors). Although the ME modelling approach in studies to assess children’s exposure to air pollution is highly encouraged, a validation process is needed, due to the uncertainties associated with the application of this approach.

P.T.B.S. Branco; M.C.M. Alvim-Ferraz; F.G. Martins; S.I.V. Sousa

2014-01-01T23:59:59.000Z

320

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

SciTech Connect

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.

Jeffrey C. JOe; Ronald L. Boring

2014-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

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

SciTech Connect

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.

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

322

Implementation of Localized Corrosion in the Performance Assessment Model for Yucca Mountain  

SciTech Connect

A total system performance assessment (TSPA) model has been developed to analyze the ability of the natural and engineered barriers of the Yucca Mountain repository to isolate nuclear waste over the 10,000-year period following repository closure. The principal features of the engineered barrier system (EBS) are emplacement tunnels (or ''drifts'') containing a two-layer waste package (WP) for waste containment and a titanium drip shield to protect the waste package from seeping water and falling rock, The 20-mm-thick outer shell of the WP is composed of Alloy 22, a highly corrosion-resistant nickel-based alloy. The barrier function of the EBS is to isolate the waste from migrating water. The water and its associated chemical conditions eventually lead to degradation of the waste packages and mobilization of the radionuclides within the packages. There are five possible waste package degradation modes of the Alloy 22: general corrosion, microbially influenced corrosion, stress corrosion cracking, early failure due to manufacturing defects, and localized corrosion. This paper specifically examines the incorporation of the Alloy-22 localized corrosion model into the Yucca Mountain TSPA model, particularly the abstraction and modeling methodology, as well as issues dealing with scaling, spatial variability, uncertainty, and coupling to other sub-models that are part of the total system model.

Vivek Jain, S. David Sevougian, Patrick D. Mattie, Kevin G. Mon, and Robert J. Mackinnon

2006-04-30T23:59:59.000Z

323

Multi-State Physics Models of Aging Passive Components in Probabilistic Risk Assessment  

SciTech Connect

Multi-state Markov modeling has proved to be a promising approach to estimating the reliability of passive components - particularly metallic pipe components - in the context of probabilistic risk assessment (PRA). These models consider the progressive degradation of a component through a series of observable discrete states, such as detectable flaw, leak and rupture. Service data then generally provides the basis for estimating the state transition rates. Research in materials science is producing a growing understanding of the physical phenomena that govern the aging degradation of passive pipe components. As a result, there is an emerging opportunity to incorporate these insights into PRA. This paper describes research conducted under the Risk-Informed Safety Margin Characterization Pathway of the Department of Energy’s Light Water Reactor Sustainability Program. A state transition model is described that addresses aging behavior associated with stress corrosion cracking in ASME Class 1 dissimilar metal welds – a component type relevant to LOCA analysis. The state transition rate estimates are based on physics models of weld degradation rather than service data. The resultant model is found to be non-Markov in that the transition rates are time-inhomogeneous and stochastic. Numerical solutions to the model provide insight into the effect of aging on component reliability.

Unwin, Stephen D.; Lowry, Peter P.; Layton, Robert F.; Heasler, Patrick G.; Toloczko, Mychailo B.

2011-03-13T23:59:59.000Z

324

Economic analysis and assessment of syngas production using a modeling approach  

SciTech Connect

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.

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

2011-08-10T23:59:59.000Z

325

Parametric modeling of transitioning cyclone’s wind fields for risk assessment studies in the western North Pacific  

Science Journals Connector (OSTI)

Probabilistic risk assessment systems for tropical cyclone hazard rely on large ensembles of model simulations to characterize cyclones tracks, intensities and the extent of the associated damaging winds. Given computational costs the wind field ...

T. Loridan; S. Khare; E. Scherer; M. Dixon; E. Bellone

326

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

SciTech Connect

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.

Shott, G. J.

2012-04-15T23:59:59.000Z

327

Lattice Boltzmann model for thermal behavior of a droplet on the solid surface  

Science Journals Connector (OSTI)

Abstract In this work, a thermal lattice Boltzmann model is applied to simulate thermal behavior of a droplet on the solid surface. For this reason Lee's model which uses the Cahn–Hilliard diffuse interface theory, is utilized to capture the droplet interface. Also contact angle between solid, liquid and gas phases has been considered in simulations. To take into account the thermal effects, passive scalar model is conjugated with the Lee's method. Since in this model the solution of temperature distribution is independent of flow field, application of the Boussinesq approximation couples the energy and momentum equations. Numerical results for two thermal boundary conditions; constant wall temperature and constant heat flux on the wall, are presented and results have been compared with previous numerical results. Results show that by increasing the Prandtl number ratio between droplet and its surrounding, thermal diffusion within the droplet will be delayed and this causes reduction in the droplet average temperature. Also it was shown that the wall heat flux is concentrated around the droplet, while that in the gas phase is negligible.

Mohammad Taghilou; Mohammad Hassan Rahimian

2014-01-01T23:59:59.000Z

328

Hydrophobic force field as molecular alternative to surface-area models  

SciTech Connect

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.

Hummer, G.

1999-07-07T23:59:59.000Z

329

Improving the assessment of wave energy resources by means of coupled wave-ocean numerical modeling  

Science Journals Connector (OSTI)

Abstract Sea waves energy represents a renewable and sustainable energy resource, that nevertheless needs to be further investigated to make it more cost-effective and economically appealing. A key step in the process of Wave Energy Converters (WEC) deployment is the energy resource assessment at a sea site either measured or obtained through numerical model analysis. In these kind of studies, some approximations are often introduced, especially in the early stages of the process, viz. waves are assumed propagating in deep waters without underneath ocean currents. These aspects are discussed and evaluated in the Adriatic Sea and its northern part (Gulf of Venice) using locally observed and modeled wave data. In particular, to account for a “state of the art” treatment of the Wave–Current Interaction (WCI) we have implemented the Simulating \\{WAves\\} Nearshore (SWAN) model and the Regional Ocean Modeling System (ROMS), fully coupled within the Coupled Ocean Atmosphere Wave Sediment Transport (COAWST) system. COAWST has been applied to a computational grid covering the whole Adriatic Sea and off-line nested to a high-resolution grid in the Gulf of Venice. A 15-year long wave data set collected at the oceanographic tower “Acqua Alta”, located approximately 15 km off the Venice coast, has also been analyzed with the dual purpose of providing a reference to the model estimates and to locally assess the wave energy resource. By using COAWST, we have quantified for the first time to our best knowledge the importance of the WCI effect on wave power estimation. This can vary up to 30% neglecting the current effect. Results also suggest the Gulf of Venice as a suitable testing site for WECs, since it is characterized by periods of calm (optimal for safe installation and maintenance) alternating with severe storms, whose wave energy potentials are comparable to those ordinarily encountered in the energy production sites.

Francesco Barbariol; Alvise Benetazzo; Sandro Carniel; Mauro Sclavo

2013-01-01T23:59:59.000Z

330

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

E-Print Network (OSTI)

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 ...

Jun, Mina

2007-01-01T23:59:59.000Z

331

Ecological-economic assessment of farms using multi-input multi-output models: life cycle assessment with multiple paired comparisons  

Science Journals Connector (OSTI)

A multi-input multi-output model is developed by extending the life cycle assessment framework for analysing the relationship between agricultural production and environmental impacts. The inputs include farmland and materials such as fertilisers, pesticides and animals. The outputs are of two types: one is agro-economic production, such as crop yields, and the other is environmental impacts, including greenhouse gas emissions. Additive and ratio models are defined for analysing the relationship between management intensity, land productivity and environmental impacts based on the farm model. After the framework of multiple paired comparisons is illustrated, the multi-input multi-output model is applied to rice farming in Japan. The results indicate that the additive and ratio models can be used for detecting the directions of changes. These models can be extended for analysing the land-use competition between food and energy production.

Kiyotada Hayashi

2014-01-01T23:59:59.000Z

332

Preliminary performance assessment for the Waste Isolation Pilot Plant, December 1992. Volume 3, Model parameters: Sandia WIPP Project  

SciTech Connect

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.

Not Available

1992-12-29T23:59:59.000Z

333

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)

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 ...

Marrocchelli, Dario

334

Immunocompetent syngeneic cotton rat tumor models for the assessment of replication-competent oncolytic adenovirus  

SciTech Connect

Oncolytic adenoviruses as a treatment for cancer have demonstrated limited clinical activity. Contributing to this may be the relevance of preclinical animal models used to study these agents. Syngeneic mouse tumor models are generally non-permissive for adenoviral replication, whereas human tumor xenograft models exhibit attenuated immune responses to the vector. The cotton rat (Sigmodon hispidus) is susceptible to human adenovirus infection, permissive for viral replication and exhibits similar inflammatory pathology to humans with adenovirus replicating in the lungs, respiratory passages and cornea. We evaluated three transplantable tumorigenic cotton rat cell lines, CCRT, LCRT and VCRT as models for the study of oncolytic adenoviruses. All three cells lines were readily infected with adenovirus type-5-based vectors and exhibited high levels of transgene expression. The cell lines supported viral replication demonstrated by the induction of cytopathogenic effect (CPE) in tissue culture, increase in virus particle numbers and assembly of virions seen on transmission electron microscopy. In vivo, LCRT and VCRT tumors demonstrated delayed growth after injection with replicating adenovirus. No in vivo antitumor activity was seen in CCRT tumors despite in vitro oncolysis. Adenovirus was also rapidly cleared from the CCRT tumors compared to LCRT and VCRT tumors. The effect observed with the different cotton rat tumor cell lines mimics the variable results of human clinical trials highlighting the potential relevance of this model for assessing the activity and toxicity of oncolytic adenoviruses.

Steel, Jason C.; Morrison, Brian J.; Mannan, Poonam [Cancer Gene Therapy Section, Metabolism Branch, Center for Cancer Research, National Cancer Institute, Mark O. Hatfield Clinical Research Center, Room 4-5330, 10 Center Drive, Bethesda, MD 20892-1457, National Institutes of Health, Maryland (United States); Abu-Asab, Mones S. [Ultrastructural Pathology, Laboratory of Pathology, National Cancer Institute, National Institutes of Health, Maryland (United States); Wildner, Oliver [Department of Molecular and Medical Virology, Ruhr University Bochum (Germany); Miles, Brian K.; Yim, Kevin C. [Virion Systems, Inc., Rockville, Maryland (United States); Ramanan, Vijay [Cancer Gene Therapy Section, Metabolism Branch, Center for Cancer Research, National Cancer Institute, Mark O. Hatfield Clinical Research Center, Room 4-5330, 10 Center Drive, Bethesda, MD 20892-1457, National Institutes of Health, Maryland (United States); Prince, Gregory A. [Virion Systems, Inc., Rockville, Maryland (United States); Morris, John C. [Cancer Gene Therapy Section, Metabolism Branch, Center for Cancer Research, National Cancer Institute, Mark O. Hatfield Clinical Research Center, Room 4-5330, 10 Center Drive, Bethesda, MD 20892-1457, National Institutes of Health, Maryland (United States)], E-mail: jmorris@mail.nih.gov

2007-12-05T23:59:59.000Z

335

Comparative Life Cycle Assessment (LCA) of passenger seats and their impact on different vehicle models  

Science Journals Connector (OSTI)

The main purpose of Life Cycle Assessment (LCA) to date has been to evaluate life cycle impacts of different design solutions and materials for a car, its sub-systems and components. Considerable number of publications are available on LCA of automotive components. This research aims to extend the LCA approach by evaluating and comparing the effects of mass reduction of passenger seats for different vehicle models in order to provide strategic support for decision making in the development process and to validate the environmental benefits of design alternatives under investigation. For this purpose, the paper presents a comprehensive LCA of passenger seats with detailed consideration of alternative scenarios for the use phase for different vehicle models.

Aleksandar Subic; Francesco Schiavone; Martin Leary; Jack Manning

2010-01-01T23:59:59.000Z

336

PORFLOW MODELING FOR A PRELIMINARY ASSESSMENT OF THE PERFORMANCE OF NEW SALTSTONE DISPOSAL UNIT DESIGNS  

SciTech Connect

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.

Smith, F.

2012-08-06T23:59:59.000Z

337

Performance of corrosion inhibiting admixtures for structural concrete -- assessment methods and predictive modeling  

SciTech Connect

During the past fifteen years corrosion inhibiting admixtures (CIAs) have become increasingly popular for protection of reinforced components of highway bridges and other structures from damage induced by chlorides. However, there remains considerable debate about the benefits of CIAs in concrete. A variety of testing methods to assess the performance of CIA have been reported in the literature, ranging from tests in simulated pore solutions to long-term exposures of concrete slabs. The paper reviews the published techniques and recommends the methods which would make up a comprehensive CIA effectiveness testing program. The results of this set of tests would provide the data which can be used to rank the presently commercially available CIA and future candidate formulations utilizing a proposed predictive model. The model is based on relatively short-term laboratory testing and considers several phases of a service life of a structure (corrosion initiation, corrosion propagation without damage, and damage to the structure).

Yunovich, M.; Thompson, N.G. [CC Technologies Labs., Inc., Dublin, OH (United States)

1998-12-31T23:59:59.000Z

338

A Shallow Water model for the numerical simulation of overland flow on surfaces with ridges and furrows  

E-Print Network (OSTI)

A Shallow Water model for the numerical simulation of overland flow on surfaces with ridges Abstract We introduce a new Shallow Water model for the numerical simulation of overland flow with furrow conservation (decreases soil thickness by erosion and causes nutrient loss), infrastruc- tures (flooding

d'Orléans, Université

339

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

E-Print Network (OSTI)

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

Meirovitch, Hagai

340

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

E-Print Network (OSTI)

-3027" DOI : 10.1080/01431161.2012.756598 #12;2 energy systems for heating and electrical power generation, high temporal and spatial resolution data for mid- and long-term energy planning are needed. Hourly on the Earth's surface and its geographical distribution is of prime importance for numerous solar

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Improving potato drought simulations: Assessing water stress factors using a coupled model  

Science Journals Connector (OSTI)

Abstract Effective water management is important for drought sensitive crops like potato (Solanum tuberosum L.). Crop simulation models are well suited for evaluating water limited responses in order to provide management and phenotypic-trait recommendations for more efficient production practice. There is considerable variation in how water stress components are implemented with regards to simulating soil, plant, and atmospheric relationships, thereby influencing the utility of model recommendations. Four water-stress factors were developed and implemented in the potato model SPUDIM in order to assess the contribution each factor provided for improving modeling accuracy. Iterative comparisons versus experimental data consisting of six irrigation treatments were used. Factors included F1, shifts in carbon allocation among shoot and root organs based on soil moisture availability, F2, coupled response of leaf water potential on leaf expansion, F3, and on stomatal conductance, and F4, increased tuber sink strength. F2 and F3 accounted for up to 88% of the improvement in root mean square error for total biomass. However, F1 and F4 were necessary to accurately simulate yield. F4 was also required to reproduce trends of increasing water-use efficiency and harvest index with declines in water availability. When the full 4-factor model was considered, simulated responses for total, leaf, stem, and tuber dry weights were within 11% of observed values. Daily comparisons for whole plant net photosynthesis and evapotranspiration indicated F3 was required to accurately simulate water use, but was too sensitive to very low leaf water potentials. The calibration coefficients used in the model remained stable over all six irrigation treatments, suggesting the full model can be utilized to evaluate water management strategies for potato.

David H. Fleisher; A. Dathe; D.J. Timlin; V.R. Reddy

2015-01-01T23:59:59.000Z

342

In situ photoelectron spectroscopy study of water adsorption on model biomaterial surfaces  

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

184024 184024 (7pp) doi:10.1088/0953-8984/20/18/184024 In situ photoelectron spectroscopy study of water adsorption on model biomaterial surfaces G Ketteler 1 , P Ashby 2 , B S Mun 3,4 , I Ratera 5 , H Bluhm 6 , B Kasemo 1 and M Salmeron 2,5 1 Chalmers University of Technology, Department of Applied Physics, 41296 Gothenburg, Sweden 2 Molecular Foundry, Lawrence Berkeley National Laboratories, Berkeley, CA 94720, USA 3 Advanced Light Source, Lawrence Berkeley National Laboratories, Berkeley, CA 94720, USA 4 Department of Applied Physics, Hanyang University, Ansan, Kyunggi-Do 426-791, Korea 5 Materials Science Division, Lawrence Berkeley National Laboratories, Berkeley, CA 94720, USA 6 Chemical Sciences Division, Lawrence Berkeley National Laboratories, Berkeley, CA 94720, USA Received 10 July 2007, in final form 13 September 2007 Published 17 April 2008 Online at stacks.iop.org/JPhysCM/20/184024

343

Assessment of near-surface dissolution at and near the Waste Isolation Pilot Plant (WIPP), southeastern New Mexico  

SciTech Connect

The area at and near the WIPP site was examined for evidence of karst development on the geomorphic surface encompassing the site. Certain surficial depressions of initial concern were identified as blowouts in sand dune fields (shallow features unrelated to karstification). An ancient stream system active more than 500,000 yr ago contained more water than any system since. During that time (Gatuna, Middle Pleistocene), many karst features such as Clayton Basin and Nash Draw began to form in the region. Halite was probably dissolved from parts of the Rustler Formation at that time. Dissolution of halite and gypsum from intervals encountered in Borehole WIPP-33 west of the WIPP site occurred during later Pleistocene time (i.e., <450,000 yr ago). However, there is no evidence of active near-surface dissolution within a belt to the east of WIPP-33 in the vicinity of the WIPP shaft. 26 refs., 11 figs., 1 tab.

Bachman, G.O.

1985-07-01T23:59:59.000Z

344

Assessing the Capability of a Regional-Scale Weather Model to Simulate Extreme Precipitation Patterns and Flooding in Central Texas  

E-Print Network (OSTI)

Assessing the Capability of a Regional-Scale Weather Model to Simulate Extreme Precipitation Patterns and Flooding in Central Texas MARLA R. KNEBL LOWREY AND ZONG-LIANG YANG Department of Geological 3 March 2008) ABSTRACT A regional-scale weather model is used to determine the potential for flood

Yang, Zong-Liang

345

Surface modeling of thin film growth: A study of silicon oxide deposition from tetraethoxysilane and silicon deposition from disilane on the Si(100) surface  

SciTech Connect

In this thesis, surface reactions brought about by the pyrolysis of adsorbed TEOS, the modeling of this reaction with ethanol, and the photolysis of adsorbed disilane have been investigated under ultrahigh vacuum conditions, using mainly temperature programmed desorption (TPD). TEOS molecularly desorbs at about 195K when adsorbed on clean Si(100) at low temperatures. When adsorbed at 300K, the primary surface species produced is a mixture of ethoxysiloxanes. Upon heating the surface in vacuum, the adsorbed ethoxysiloxanes decompose the evolve ethylene and hydrogen, with trace production of acetylene and acetaldehyde. In a parallel study, the adsorption and subsequent deposition of ethanol (C[sub 2]H[sub 5]OH, C[sub 2]D[sub 5]OD, and CH[sub 3]CD[sub 2]OH) on Si(100) has been shown to model the TEOS system. The molecular desorption temperature is ca. 150K. When adsorbed at 200K, ethanol dissociatively chemisorbs as an ethoxide and the monohydride species. The adlayer decomposes at higher temperature to evolve ethylene, hydrogen, acetaldehyde, and acetylene. The adsorption and decomposition of ethanol on Si(100)-2x1:H has also been studied in gathering additional information about the competition between distinct decomposition mechanisms, and the nature of the reaction site. In the Si[sub 2]H[sub 6]/Si(100) system, with no UV irradiation, disilane adsorption at 120K produces a chemisorbed SiH[sub x] (x = 1 - 3) layer and, for high exposures, a disilane multilayer. Upon heating the surface in vacuum, molecular desorption is observed at ca. 150K, while hydrogen and silane are evolved at much higher temperatures. For Si[sub 2]H[sub 6] exposure during photo-irradiation, the desorption yields of hydrogen and silane are enhanced. Model studies using the partially and fully deuterated Si(100)-2x1:D surface reveals that the photo-induced surface reaction is dominated by an insertion reaction by the photo-generated silylene species.

Cho, Hee-Chuen.

1993-01-01T23:59:59.000Z

346

New adatom model for Si(111) 7×7 and Si(111)-Ge 5×5 reconstructed surfaces  

Science Journals Connector (OSTI)

A new adatom structure with significantly less angular strain than the simple adatom geometry is proposed. The model involves a rebonding of ?? of surface atoms to the substrate in a manner similar to that occurring in the ?-bonded-chain structure for the Si(111) 2×1 surface. The interference between adatom and substrate reconstructions forces the smallest threefold-symmetric unit cells to be 5×5 and 7×7 in size. The proposed reconstructed-adatom model gives rise to structural features in good agreement with experiment. In particular, the inhomogeneous corrugation of the two halves of the 7×7 unit cell seen in vacuum-tunneling microscopy and the apparent need for stacking fault sequences in ion-channeling experiments are accounted for. The results of surface energy and structure calculations on 2×2, 3×3, 5×5, and 7×7 adatom models are presented.

D. J. Chadi

1984-10-15T23:59:59.000Z

347

Detailed comparative study and a mechanistic model of resuspension of spherical particles from rough and smooth surfaces  

E-Print Network (OSTI)

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.

Shnapp, Ron

2014-01-01T23:59:59.000Z

348

A model for assessing the impact of vessel noise on odontocete communication  

Science Journals Connector (OSTI)

Offshore industrial noisesources ensonify marine mammal habitat and may mask detection of social signals and important environmental sounds. A probabilistic model of sound detection was developed for assessing the impact of underwater icebreaker noise on signal detection by beluga whales and narwhals. The probability of detecting sample signals in the absence of vessel noise was compared to that of detecting the same signals in ship noise using the MV arctic as a sample noisesource.Analysis of signal detection probabilities showed that loud signals centered on the 5?kHz critical band were more severely masked by ship noise than were quiet 5?kHz signals or loud 2?kHz signals. Thus long?range calls seem to be more susceptible to masking by ship noise than are short?range calls. The model could also be applied to other critical bands of interest. Changes in the probability of detecting vessel noise as estimated by the model were also correlated with changes in beluga and narwhal behavior observed in response to the vessel in operation.

Susan E. Cosens

1993-01-01T23:59:59.000Z

349

New approach to risk assessment of central neurotoxicity induced by 1-bromopropane using animal models  

Science Journals Connector (OSTI)

1-Bromopropane (1-BP) induces central as well as peripheral neurotoxicity in workers. We have reported the dysfunction of feedback inhibition (i.e. disinhibition) in the rat hippocampus following exposure to 1-BP at concentrations of 1500 and 700 ppm. For risk assessment, we studied disinhibition of the CA1 region and the dentate gyrus in hippocampal slices obtained from control and 1-BP-exposed (200 and 400 ppm) rats, and determined the bromide concentration in the brain. Granule cell disinhibition was observed after inhalation exposure to 400 ppm 1-BP for 8 or 12 weeks, suggesting that the dentate gyrus was more sensitive than the CA1 region to 1-BP exposure. The lowest observed adverse effect level and the no observed adverse effect level of 1-BP inhalation for disinhibition were 400 and 200 ppm, respectively. The concentration of bromides in the brain increased from 2.9 ± 1.5 to 85.0 ± 25.4 ?g/g-wet brain at week 4 of 400 ppm inhalation, and no further increase was observed even when the exposure period was extended for up to 12 weeks. The relationship between total dose (ppm-h) and the exposure concentration of 1-BP was investigated at different exposure concentrations. Disinhibition and death by inhalation depended on the total dose, and their occurrence appeared earlier as the exposure concentration increased. The results demonstrated a novel model for risk assessment of central neurotoxicity induced by 1-BP inhalation.

Yukiko Fueta; Toru Ishidao; Susumu Ueno; Yasuhiro Yoshida; Naoki Kunugita; Hajime Hori

2007-01-01T23:59:59.000Z

350

A model of the macro-features of the surface layer of a cometary nucleus  

Science Journals Connector (OSTI)

......say, the Rosetta landing probe is in considerable doubt. comets: general|dust...the surface of the comet. The conclusions...small weight of a landing probe, is in considerable...very material. The comet surface regions are......

David W. Hughes

2000-08-11T23:59:59.000Z

351

A two-dimensional model of low-Reynolds number swimming beneath a free surface  

E-Print Network (OSTI)

Biological organisms swimming at low-Reynolds number are often influenced by the presence of rigid boundaries and soft interfaces. In this paper, we present an analysis of locomotion near a free surface with surface tension. ...

Crowdy, Darren

352

Wildfire Risk Mapping over the State of Mississippi: Land Surface Modeling Approach  

SciTech Connect

Three fire risk indexes based on soil moisture estimates were applied to simulate wildfire probability over the southern part of Mississippi using the logistic regression approach. The fire indexes were retrieved from: (1) accumulated difference between daily precipitation and potential evapotranspiration (P-E); (2) top 10 cm soil moisture content simulated by the Mosaic land surface model; and (3) the Keetch-Byram drought index (KBDI). The P-E, KBDI, and soil moisture based indexes were estimated from gridded atmospheric and Mosaic-simulated soil moisture data available from the North American Land Data Assimilation System (NLDAS-2). Normalized deviations of these indexes from the 31-year mean (1980-2010) were fitted into the logistic regression model describing probability of wildfires occurrence as a function of the fire index. It was assumed that such normalization provides more robust and adequate description of temporal dynamics of soil moisture anomalies than the original (not normalized) set of indexes. The logistic model parameters were evaluated for 0.25 x0.25 latitude/longitude cells and for probability representing at least one fire event occurred during 5 consecutive days. A 23-year (1986-2008) forest fires record was used. Two periods were selected and examined (January mid June and mid September December). The application of the logistic model provides an overall good agreement between empirical/observed and model-fitted fire probabilities over the study area during both seasons. The fire risk indexes based on the top 10 cm soil moisture and KBDI have the largest impact on the wildfire odds (increasing it by almost 2 times in response to each unit change of the corresponding fire risk index during January mid June period and by nearly 1.5 times during mid September-December) observed over 0.25 x0.25 cells located along the state of Mississippi Coast line. This result suggests a rather strong control of fire risk indexes on fire occurrence probability over this region.

Cooke, William H. [Mississippi State University (MSU); Mostovoy, Georgy [Mississippi State University (MSU); Anantharaj, Valentine G [ORNL; Jolly, W. Matt [USDA Forest Service

2012-01-01T23:59:59.000Z

353

Integrated LCA–LEED sustainability assessment model for structure and envelope systems of school buildings  

Science Journals Connector (OSTI)

Abstract In Canada and USA, nearly 80 million students and teachers spend at least eight hours daily in schools that could be unhealthy and restrict their ability to learn. Despite this fact there is lack of adopting sustainability principles in school buildings. Even though life cycle assessment (LCA) and LEED® could serve as sustainability measurement tools, studies show that the integration of sustainability principles to LCA has not become standard practice yet. This paper presents an integrated LCA–LEED model that incorporates LCA into LEED and assigns corresponding LEED scores to achieve a high level of sustainability assessment, for the structure and envelope systems of Canadian school buildings. In this model, the selection of the most sustainable structure and envelope type for school buildings is done through the evaluation of three categories of the LEED rating system: energy and atmosphere, materials and resources, and LCA (incorporated under the innovation and design process category of LEED). Various options are tested by considering structures such as concrete, steel, masonry and wood, and envelope types such as precast panels, steel stud, wood stud and cavity wall. Energy simulation is performed by eQUEST® (version 3.64) program and LCA is performed by ATHENA® impact estimator. The results show that concrete and masonry buildings have high energy consumption and global warming potential during certain life cycle stages such as manufacturing, construction and demolition. However they have lower annual energy consumption and environmental impact during the operating stage, as well as for the overall life span. Concrete building with minimum insulation has obtained the highest total LEED score (19) followed by masonry (17), while steel and steel-masonry buildings have the least score (14).

Othman Subhi Alshamrani; Khaled Galal; Sabah Alkass

2014-01-01T23:59:59.000Z

354

Probabilistic ecological risk assessment and source apportionment of polycyclic aromatic hydrocarbons in surface sediments from Yellow Sea  

SciTech Connect

Based on the concentrations of polycyclic aromatic hydrocarbons (PAHs) in 12 surface sediment samples from Yellow Sea, the relative risk of 9 PAHs was investigated using joint risk probability distribution curves and overlapping area, which were generated based on the distributions of exposure and acute toxicity data (LC50), and the sources of PAHs were apportioned using principal component analysis. It was found that joint probability curve and overlapping area indicated the acceptable ecological risk of individual PAHs, only a small fraction of the benthic organisms was affected. Among the nine PAHs studied, the overall risk of pyrene was the highest, with that of naphthalene the lowest. For lower exposure levels at which the percentage of species affected was less than 10%, the risk associated with phenanthrene and fluorene were clearly higher than that of the other seven PAHs. It was indicated that PAHs in surface sediments mainly originated from vehicular emissions, coal combustion sources, coke oven emission and wood combustion, petroleum origin made little influence on sources of PAHs by PCA.

Liu, A.X.; Lang, Y.H.; Xue, L.D.; Liao, S.L.; Zhou, H. [Ocean University of China, Qingdao (China). College for Environmental Science & Engineering

2009-11-15T23:59:59.000Z

355

Repository Integration Program: RIP performance assessment and strategy evaluation model theory manual and user`s guide  

SciTech Connect

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.

NONE

1995-11-01T23:59:59.000Z

356

Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature  

E-Print Network (OSTI)

to local SST perturbations decreases rapidly with height to near-zero at 150-300m. The simulated wind speed of local SST perturbations, and the orientation of the surface wind to the SST gradient. #12;3 1. Introduction Positive correlations of local surface wind anomalies with sea surface temperature (SST) anomalies

357

Air quality modelling as a supplementary assessment method in the framework of the European Air Quality Directive  

Science Journals Connector (OSTI)

According to the European Air Quality (AQ) Directive, member states must annually report their AQ to the European Commission (EC). This report can be based on modelling data if the concentration levels do not exceed the established lower assessment thresholds (LAT), or on combined data from modelling and monitoring systems (supplementary assessment methods) if concentrations levels are below the upper assessment threshold (UAT). This work presents and applies a methodology that combines air pollutant concentration values from monitored data and from a numerical modelling system to deliver AQ information for Portugal in 2010. This methodology produces improved information, especially for areas where the amount of fixed monitoring stations is sparse or non-existent, allowing obtaining a better and broader overview of the AQ in Portugal to support AQ reporting to the European Commission.

I. Ribeiro; A. Monteiro; A.P. Fernandes; A.C. Monteiro; M. Lopes; C. Borrego; A.I. Miranda

2014-01-01T23:59:59.000Z

358

EXPERIMENTAL DESIGN APPLICATIONS FOR MODELING AND ASSESSING CARBON DIOXIDE SEQUESTRATION IN SALINE AQUIFERS  

SciTech Connect

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.

Rogers, John

2014-08-31T23:59:59.000Z

359

Modeling  

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

a single-fluid diffuse interface model in the ALE-AMR hydrodynamics code to simulate surface tension effects. We show simula- tions and compare them to other surface tension...

360

Testing, Modeling, and Monitoring to Enable Simpler, Cheaper, Longer-lived Surface Caps  

SciTech Connect

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.

Piet, S. J.; Breckenridge, R. P.; Burns, D. E.

2003-02-25T23:59:59.000Z

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Testing, Modeling, and Monitoring to Enable Simpler, Cheaper, Longer-Lived Surface Caps  

SciTech Connect

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.

Piet, Steven James; Breckenridge, Robert Paul; Burns, Douglas Edward

2003-02-01T23:59:59.000Z

362

Assessing the Effects of Anthropogenic Aerosols on Pacific Storm Track Using a Multiscale Global Climate Model  

SciTech Connect

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.

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

363

A Moduli Space of the Quaternionic Hopf Surface Encodes Standard Model Physics  

E-Print Network (OSTI)

The quaternionic Hopf surface, HL, is associated with a non-compact moduli space, ML, of stable holomorphic SL(2,C) bundles. ML is open in MLc, the corresponding compact moduli space of holomorphic SL(2,C) bundles, and naturally fibers over an open set of the quaternionic projective line HP^1. We pull back to ML natural locally conformal kaehler and hyperkaehler structures from MLc, and lift natural sub-pseudoriemannian and optical structures from HP^1. Unexpectedly, the holomorphic maps connecting these structures solve the the classical Dirac-Higgs equations of the unbroken Standard Model. These equations include: all observed fermionic and bosonic fields of all three generations with the correct color, weak isospin, and hypercharge values; a Higgs field coupling left and right fermion fields; and a pp-wave gravitational metric. We hypothesize that physics is essentially the geometry of ML, both algebraic (quantum) and differential (classical). We further show that the Yang-Mills equations with fermionic currents also naturally emerge, along with an induced action on the ML structure sheaf equivalent to the time-evolution operator of the associated quantum field theory.

Colin B. Hunter

2012-09-13T23:59:59.000Z

364

Improving Surface Radiation in a Satellite-Based Physical Model (Poster)  

SciTech Connect

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.

Sengupta, M.; Habte, A.; Gotseff, P.

2013-10-01T23:59:59.000Z

365

Environmental impact of APC residues from municipal solid waste incineration: Reuse assessment based on soil and surface water protection criteria  

SciTech Connect

Highlights: > The Dutch Building Material Decree (BMD) was used to APC residues from MSWI. > BMD is a straightforward tool to calculate expectable loads to the environment of common pollutants. > Chloride load to the environment lead to classification of building material not allowed. > At least a pre-treatment (e.g. washing) is required in order to remove soluble salts. > The stabilization with phosphates or silicates eliminate the problem of heavy metals. - Abstract: Waste management and environmental protection are mandatory requirements of modern society. In our study, air pollution control (APC) residues from municipal solid waste incinerators (MSWI) were considered as a mixture of fly ash and fine particulate solids collected in scrubbers and fabric filters. These are hazardous wastes and require treatment before landfill. Although there are a number of treatment options, it is highly recommended to find practical applications rather than just dump them in landfill sites. In general, for using a construction material, beyond technical specifications also soil and surface water criteria may be used to ensure environmental protection. The Dutch Building Materials Decree (BMD) is a valuable tool in this respect and it was used to investigate which properties do not meet the threshold criteria so that APC residues can be further used as secondary building material. To this end, some scenarios were evaluated by considering release of inorganic species from unmoulded and moulded applications. The main conclusion is that the high amount of soluble salts makes the APC residues a building material prohibited in any of the conditions tested. In case of moulding materials, the limits of heavy metals are complied, and their use in Category 1 would be allowed. However, also in this case, the soluble salts lead to the classification of 'building material not allowed'. The treatments with phosphates or silicates are able to solve the problem of heavy metals, but difficulties with the soluble salts are still observed. This analysis suggests that for APC residues to comply with soil and surface water protection criteria to be further used as building material at least a pre-treating for removing soluble salts is absolutely required.

Quina, Margarida J., E-mail: guida@eq.uc.pt [Research Centre on Chemical Processes Engineering and Forest Products, Department of Chemical Engineering, University of Coimbra, Rua Silvio Lima, 3030-790 Coimbra (Portugal); Bordado, Joao C.M. [Department of Chemical and Biological Engineering, IBB, Instituto Superior Tecnico, Av. Rovisco Pais, 1049-001 Lisboa (Portugal); Quinta-Ferreira, Rosa M. [Research Centre on Chemical Processes Engineering and Forest Products, Department of Chemical Engineering, University of Coimbra, Rua Silvio Lima, 3030-790 Coimbra (Portugal)

2011-09-15T23:59:59.000Z

366

Coupling GIS and LCA for biodiversity assessments of land use: Part 1: Inventory modeling  

E-Print Network (OSTI)

467 DOI 10.1007/s11367-010-0170-9 LAND USE IN LCA CouplingGIS and LCA for biodiversity assessments of land use Part 1:while life cycle assessment (LCA) does not conventionally

Geyer, Roland; Stoms, David M.; Lindner, Jan P.; Davis, Frank W.; Wittstock, Bastian

2010-01-01T23:59:59.000Z

367

Effects of vegetation and soil moisture on the simulated land surface processes from the coupled WRF/Noah model  

E-Print Network (OSTI)

simulations. Meso- scale models, which have been used not only for numerical weather prediction but also surface and atmosphere into numerical weather or climate prediction. This study describes coupled WRF [Chen et al., 1997; Pielke et al., 1997]. Numerical weather prediction with high spatial and tempo- ral

Small, Eric

368

Mechanical models of fracture reactivation and slip on bedding surfaces during folding of the asymmetric anticline at Sheep Mountain, Wyoming  

E-Print Network (OSTI)

Mechanical models of fracture reactivation and slip on bedding surfaces during folding June 2008 Accepted 5 June 2008 Available online 13 June 2008 Keywords: Fold Fracture reactivation Bed methods to investigate the reactivation of fractures (opening and shearing) and the development of bedding

Borja, Ronaldo I.

369

Molecular Dynamics Modeling of Ion Adsorption to the Basal Surfaces of Kaolinite  

SciTech Connect

Molecular dynamics simulation is used to study the mechanisms involved in the adsorption of various ions to the basal surfaces of kaolinite. Analysis of simulation data indicates that cations and anions adsorb preferably on the siloxane and gibbsite surfaces of kaolinite, respectively. Strong inner-sphere adsorption of chlorine at aluminum vacancies on the gibbsite surface and the occurrence of chlorine-driven inner-sphere adsorption of cesium and sodium on the gibbsite surface for high ionic strengths are observed. Cesium ions form strong inner-sphere complexes at ditrigonal cavities on the siloxane surface. Outer-sphere cesium is highly mobile and only weak adsorption may occur. A small amount of sodium adsorbs on the siloxane surface as inner-sphere complexes at less clearly defined sites. Like cesium, sodium only forms very weak outer-sphere complexes on this surface. Inner-sphere complexes of cadmium and lead do not occur on either surface. Relatively strong outer-sphere cadmium and lead complexes are present on the siloxane surface at ditrigonal cavities.

Vasconcelos, Igor F.; Bunker, Bruce A.; Cygan, Randall T. (Sandia); (Notre)

2008-06-06T23:59:59.000Z

370

In situ photoelectron spectroscopy study of water adsorption on model biomaterial surfaces  

E-Print Network (OSTI)

or solid-vacuum) interface in UHV conditions (UHV) with surface sensitivestudy. An ultra-high vacuum (UHV) chamber dedicated for

Ketteler, Guido

2008-01-01T23:59:59.000Z

371

Carbon sequestration by patch fertilization: A comprehensive assessment using coupled physical-ecological-biogeochemical models  

SciTech Connect

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.

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

372

Surface spectroscopic characterization of oxide thin films and bimetallic model catalysts  

E-Print Network (OSTI)

of the surface morphology and electronic/geometric structure of the following catalysts: SiO2/Mo(112), Ag/SiO2/Mo(112), Au–Pd/Mo(110), Au–Pd/SiO2/Mo(110), and Pd– Sn/Rh(100). Specifically, different types of oxide surface defects were directly identified by MIES...

Wei, Tao

2009-05-15T23:59:59.000Z

373

ASSESSMENT FOR THE SOUTHWEST  

E-Print Network (OSTI)

SERVICE CLIMATE CHANGE & CULTURAL RESOURCE PLANNING PROGRAM 17 EARTH SYSTEM MODELS 18 CLIMATE ASSESSMENTS

Wong, Pak Kin

374

A Modeling Study of Irrigation Effects on Surface Fluxes and Land-Air-Cloud Interactions in the Southern Great Plains  

SciTech Connect

In this study, the authors incorporate an operational-like irrigation scheme into the Noah land surface model as part of the Weather Research and Forecasting Model (WRF). A series of simulations, with and without irrigation, is conducted over the Southern Great Plains (SGP) for an extremely dry (2006) and wet (2007) year. The results show that including irrigation reduces model bias in soil moisture and surface latent heat (LH) and sensible heat (SH) fluxes, especially during a dry year. Irrigation adds additional water to the surface, leading to changes in the planetary boundary layer. The increase in soil moisture leads to increases in the surface evapotranspiration and near-surface specific humidity but decreases in the SH and surface temperature. Those changes are local and occur during daytime. There is an irrigation-induced decrease in both the lifting condensation level (ZLCL) and mixed-layer depth. The decrease in ZLCL is larger than the decrease in mixed-layer depth, suggesting an increasing probability of shallow clouds. The simulated changes in precipitation induced by irrigation are highly variable in space, and the average precipitation over the SGP region only slightly increases. A high correlation is found among soil moisture, SH, and ZLCL. Larger values of soil moisture in the irrigated simulation due to irrigation in late spring and summer persist into the early fall, suggesting that irrigation-induced soil memory could last a few weeks to months. The results demonstrate the importance of irrigation parameterization for climate studies and improve the process-level understanding on the role of human activity in modulating land–air–cloud interactions.

Qian, Yun; Huang, Maoyi; Yang, Ben; Berg, Larry K.

2013-06-13T23:59:59.000Z

375

A Multi-State Model for the Reliability Assessment of a Distributed Generation System via Universal Generating Function  

E-Print Network (OSTI)

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 of discretized solar irradiance states Discretized solar irradiance at state i Random variable representing

Boyer, Edmond

376

IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 22, NO. 1, FEBRUARY 2007 85 A Reinforcement Learning Model to Assess Market  

E-Print Network (OSTI)

IEEE TRANSACTIONS ON POWER SYSTEMS, VOL. 22, NO. 1, FEBRUARY 2007 85 A Reinforcement Learning Model to Assess Market Power Under Auction-Based Energy Pricing Vishnuteja Nanduri, Student Member, IEEE, and Tapas K. Das, Member, IEEE Abstract--Auctions serve as a primary pricing mechanism in various market

Tesfatsion, Leigh

377

Modeling Miscanthus in the Soil and Water Assessment Tool (SWAT) to Simulate Its Water Quality Effects As a Bioenergy Crop  

Science Journals Connector (OSTI)

Modeling Miscanthus in the Soil and Water Assessment Tool (SWAT) to Simulate Its Water Quality Effects As a Bioenergy Crop ... There is increasing interest in perennial grasses as a renewable source of bioenergy and feedstock for second-generation cellulosic biofuels. ... Due to global warming and energy independence concerns, there is increasing interest in perennial grasses as a renewable source of bioenergy. ...

Tze Ling Ng; J. Wayland Eheart; Ximing Cai; Fernando Miguez

2010-08-03T23:59:59.000Z

378

Wind assessment in complex terrain with the numeric model Aiolos implementation of the influence of roughness changes and stability  

E-Print Network (OSTI)

Wind assessment in complex terrain with the numeric model Aiolos ­ implementation of the influence of roughness changes and stability Ulrich Focken, Detlef Heinemann, Hans-Peter Waldl Department of Energy (EWA) gives good results for the wind potential estimation in flat areas. But besides many

Heinemann, Detlev

379

Modeling and comparative assessment of municipal solid waste gasification for energy production  

SciTech Connect

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.

Arafat, Hassan A., E-mail: harafat@masdar.ac.ae; Jijakli, Kenan

2013-08-15T23:59:59.000Z

380

Physica 65 (1973) 73-88 0 North-Holland Publishing Co. SURFACE TENSION IN THE TWO-DIMENSIONAL ISING MODEL  

E-Print Network (OSTI)

Physica 65 (1973) 73-88 0 North-Holland Publishing Co. SURFACE TENSION IN THE TWO-DIMENSIONAL ISING of surface tension between oppositely magnetised phases in the two-dimensional Ising model. With nearest?) defined and calculated exactly a surface tension. This was later shown by Fisher and Ferdinand5

Roma "La Sapienza", Università di

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Overview of total system model used for the 2008 performance assessment for the proposed high-level radioactive waste repository at Yucca Mountain, Nevada  

Science Journals Connector (OSTI)

Abstract A summary is presented for the total system model used to represent physical processes associated with the seven scenario classes (i.e., nominal conditions, early waste package (WP) failure, early drip shield (DS) failure, igneous intrusive events, igneous eruptive events, seismic ground motion events and seismic fault displacement events) considered in the 2008 performance assessment for the proposed repository for high-level radioactive waste at Yucca Mountain, Nevada. The total system model estimates dose to an exposed individual resulting from radionuclide movement through the repository system and biosphere. Components of the total system model described in this presentation include models for (i) climate analysis, (ii) land surface infiltration and associated unsaturated zone flow, (iii) multi-scale thermal hydrology and engineered barrier system (EBS) thermal–hydrologic environment, (iv) EBS physical and chemical environment, (v) WP and DS degradation, (vi) drift seepage and drift wall condensation, (vii) waste form degradation and mobilization, (viii) water and radionuclide movement in the EBS and underlying unsaturated and saturated zones, (ix) radionuclide movement in the biosphere and resultant human exposure, and (x) processes specific to early WP and DS failures, intrusive and eruptive igneous events, and seismic ground motion and fault displacement events.

C.W. Hansen; J.T. Birkholzer; J. Blink; C.R. Bryan; Y. Chen; M.B. Gross; E. Hardin; J. Houseworth; R. Howard; R. Jarek; K.P. Lee; B. Lester; P. Mariner; P.D. Mattie; S. Mehta; F.V. Perry; B. Robinson; D. Sassani; S.D. Sevougian; J.S. Stein; M. Wasiolek

2014-01-01T23:59:59.000Z

382

Research utilization in the building industry: decision model and preliminary assessment  

SciTech Connect

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.

Watts, R.L.; Johnson, D.R.; Smith, S.A.; Westergard, E.J.

1985-10-01T23:59:59.000Z

383

Sensitivity of Surface Flux Simulations to Hydrologic Parameters Based on an Uncertainty Quantification Framework Applied to the Community Land Model  

SciTech Connect

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.

Hou, Zhangshuan; Huang, Maoyi; Leung, Lai-Yung R.; Lin, Guang; Ricciuto, Daniel M.

2012-08-10T23:59:59.000Z

384

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)

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 ...

Patra, P. K.

385

Surface mine reclamation for wildlife: a model reclamation plan for southern Appalachia. Final report  

SciTech Connect

A reclamation plan for use on surface coal mines in southern Appalachia is presented. Included are suggestions relative to the establishment of groundcover and trees on the mine site. Also included are suggestions relative to the retention of surface water on mine sites. All techniques mentioned in the plan benefit wildlife and will assist the operator in achieving bond release. This plan has been implemented cooperatively by TVA and the FWS on a mine site in Campbell County, Tennessee. The costs of reclaiming a coal surface mine in Campbell County, Tennessee to benefit wildlife are described. The reclamation plan implemented on the mine site was designed for forestry and wildlife.

Fowler, D.K.; Turner, L.J.; Slaski, L.J.

1981-06-01T23:59:59.000Z

386

E-Print Network 3.0 - assessment models final Sample Search Results  

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

ment categories... majority of the 164 assessment units in CASP8 ... Source: Richardson, David - Department of Biochemistry, Duke University Collection: Biotechnology ; Biology...

387

SciTech Connect: Using a Simple Binomial Model to Assess Improvement...  

Office of Scientific and Technical Information (OSTI)

Assess Improvement in Predictive Capability: Sequential Bayesian Inference, Hypothesis Testing, and Power Analysis Citation Details In-Document Search Title: Using a Simple...

388

MODELS FOR ASSESSMENT OF FLAWS IN PRESSURE TUBES OF CANDU REACTORS.  

E-Print Network (OSTI)

??Probabilistic assessment and life cycle management of engineering components and systems in a nuclear power plant is intended to ensure safe and efficient operation of… (more)

Sahoo, Anup Kumar

2009-01-01T23:59:59.000Z

389

Markov-Switching models and resultant equity implied volatility surfaces: a South African application.  

E-Print Network (OSTI)

??Includes abstract. Standard Geometric Brownian Motion is the stock model underlying Black-Scholes famous option pricing formula. There are however numerous problems with this stock model… (more)

Fairbrother, Mark.

2012-01-01T23:59:59.000Z

390

Tribological contact analysis of a rigid ball sliding on a hard coated surface: Part I: Modelling stresses and strains  

Science Journals Connector (OSTI)

The stress and fracture conditions of a coated surface, that are the origin to wear, were analysed by three-dimensional finite element method (FEM) modelling on microlevel, by stress and strain computer simulations and by experimental studies with a scratch tester. The studied tribological contact was a 0.2 mm radius diamond ball sliding with increasing load on a thin, 2 ?m thick titanium nitride (TiN) coating on a flat high speed steel substrate. The ball was modelled as rigid, the coating linearly elastic and the steel substrate elastic–plastic taking into account strain hardening effects. The stresses and strains generated in the surface during sliding are the result of four different mechanisms: the pulling and pushing by the friction force; the geometrical indent, groove, and torus shaped deformations of the flat surface; the bulk plasticity concentration and curvature minimum effects; and the residual stresses in the coating. In a sliding contact the first crack is initiated at the top of the coating from bending and pulling actions and it grows down through the coating. In the modelled scratch tester system a complex stress field is formed at the surface including remaining residual stresses in the coating behind the sliding contact. The stress fields are very different in a scratched uncoated steel sample. Some residual tensile stresses are formed in the groove behind the tip but they are very much lower than for the TiN coated case. A displacement controlled FEM model was found to better represent the real situation and correspond to experimental results than a force controlled model.

Kenneth Holmberg; Anssi Laukkanen; Helena Ronkainen; Kim Wallin; Simo Varjus; Jari Koskinen

2006-01-01T23:59:59.000Z

391

Seismic Performance, Modeling, and Failure Assessment of Reinforced Concrete Shear Wall Buildings  

E-Print Network (OSTI)

22 Modeling of Building23 Modeling of Building1.0 GA g 2.2.7. Modeling of Building 2A The 3-D nonlinear

Tuna, Zeynep

2012-01-01T23:59:59.000Z

392

Bottom-up Representation of Industrial Energy Efficiency Technologies in Integrated Assessment Models for the Cement Sector  

SciTech Connect

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.

Sathaye, J.; Xu, T.; Galitsky, C.

2010-08-15T23:59:59.000Z

393

The Hierarchy of Adsorption Models for Laterally Interacting Molecules on Heterogeneous Surfaces  

Science Journals Connector (OSTI)

Real adsorbents are heterogeneous, therefore, the computation of the adsorption characteristics for any concentration of adsorbate must take account of the joint effect of the lateral interaction between adsorbed molecules and surface heterogeneity. The ...

Yu. K. Tovbin

1997-03-05T23:59:59.000Z

394

Tribological analysis of fracture conditions in thin surface coatings by 3D FEM modelling and stress simulations  

Science Journals Connector (OSTI)

A tribological analysis of deformations and stresses generated and their influence on crack generation and surface fracture in a coated surface loaded by a sliding sphere in dry conditions is presented. A three-dimensional finite element method (3D FEM) model has been developed for calculating the first principal stress distribution in the scratch tester contact of a diamond spherical tip with 200 ?m radius sliding with increasing load on a 2 ?m thick titanium nitride coated steel surface. The model is comprehensive in that sense that it considers elastic, plastic and fracture behaviour of the surfaces. The hard coating will be stretched and accumulates high tensile stresses. At the same time, it is carrying part of the load and thus reducing the compressional stresses in the substrate under the sliding tip. The first crack is initiated at the top of the coating from bending and pulling actions and it grows down through the coating. The fracture toughness of the coating is calculated by identifying from a scratch test experiment the location of the first cracks and the crack density and using this as input data.

Kenneth Holmberg; Anssi Laukkanen; Helena Ronkainen; Kim Wallin

2006-01-01T23:59:59.000Z

395

Home composting as an alternative treatment option for organic household waste in Denmark: An environmental assessment using life cycle assessment-modelling  

SciTech Connect

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.

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

396

Coupling of kinetic Monte Carlo simulations of surface reactions to transport in a fluid for heterogeneous catalytic reactor modeling  

SciTech Connect

We have developed a method to couple kinetic Monte Carlo simulations of surface reactions at a molecular scale to transport equations at a macroscopic scale. This method is applicable to steady state reactors. We use a finite difference upwinding scheme and a gap-tooth scheme to efficiently use a limited amount of kinetic Monte Carlo simulations. In general the stochastic kinetic Monte Carlo results do not obey mass conservation so that unphysical accumulation of mass could occur in the reactor. We have developed a method to perform mass balance corrections that is based on a stoichiometry matrix and a least-squares problem that is reduced to a non-singular set of linear equations that is applicable to any surface catalyzed reaction. The implementation of these methods is validated by comparing numerical results of a reactor simulation with a unimolecular reaction to an analytical solution. Furthermore, the method is applied to two reaction mechanisms. The first is the ZGB model for CO oxidation in which inevitable poisoning of the catalyst limits the performance of the reactor. The second is a model for the oxidation of NO on a Pt(111) surface, which becomes active due to lateral interaction at high coverages of oxygen. This reaction model is based on ab initio density functional theory calculations from literature.

Schaefer, C.; Jansen, A. P. J. [Eindhoven University of Technology, P.O. Box 513, 5600 MB Eindhoven (Netherlands)

2013-02-07T23:59:59.000Z

397

Multi-scale modeling and evaluation of urban surface energy balance in the Phoenix metropolitan area  

Science Journals Connector (OSTI)

Physical mechanisms of incongruency between observations and Weather Research and Forecasting (WRF) model predictions are examined. Limitations of evaluation are constrained by: i) parameterizations of model physics, ii) parameterizations of input ...

S.R. Shaffer; W.T.L. Chow; M. Georgescu; P. Hyde; G.D. Jenerette; A. Mahalov; M. Moustaoui; B.L. Ruddell

398

The Risk Assessment Information System  

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

Risk Assessment Documents Risk Assessment Documents ORNL RA Graphic Results ORNL Baseline Risk Assessment Results ORNL Screening Risk Assessment Results ORNL Other Risk Assessment Results ORNL RA Graphic Results WAG 2 Residential Landuse Sediment - Total Risk Sediment - Cesium 137 Risk Sediment - Cobalt 60 Risk Surface Water - Total Hazard Surface Water - Total Risk Surface Water - Strontium 90 Risk Surface Water - Tritium Risk Recreational Landuse Sediment - Total Risk Sediment - Cesium 137 Risk Sediment - Cobalt 60 Risk Surface Water - Total Hazard Surface Water - Total Risk Surface Water - Strontium 90 Risk Surface Water - Tritium Risk Recreational Landuse (No Fish) Surface Water - Total Hazard Surface Water - Total Risk Surface Water - Strontium 90 Risk Surface Water - Tritium Risk Industrial Landuse

399

Wind resource assessment using numerical weather prediction models and multi-criteria decision making technique: case study (Masirah Island, Oman)  

Science Journals Connector (OSTI)

The Authority for Electricity Regulation in Oman has recently announced the implementation of a 500 kW wind farm pilot project in Masirah Island. Detailed wind resource assessment is then required to identify the most suitable location for this project. This paper presents wind resource assessment using nested ensemble numerical weather prediction (NWP) model's approach at 2.8 km resolution and multi-criteria decision making (MCDM) technique. A case study based on the proposed approach is conducted over Masirah Island, Oman. The resource assessment over the island was based on the mean wind speed and wind power distribution over the entire island at different heights. In addition, important criteria such as turbulence intensity and peak hour matching are also considered. The NWP model results were verified against the available 10 m wind data observations from the meteorological station in the northern part of the island. The resource assessment criteria were evaluated using MCDM technique to score the locations over the island based on their suitability for wind energy applications. Two MCDM approaches namely equally weighted and differently weighted criteria were implemented in this paper.

Sultan Al-Yahyai; Yassine Charabi; Abdullah Al-Badi; Adel Gastli

2013-01-01T23:59:59.000Z

400

Assessing the impact of marine wind farms on birds through movement modelling  

Science Journals Connector (OSTI)

...post-construction of the Danish Nysted offshore wind farm were used to parameterize competing...Somateria mollissima |Nysted offshore wind farm| 1. Introduction Many countries...post-construction assessment of an offshore wind farm, and to quantitatively describe...

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Performance Assessment Modeling for Savannah River Glass HLW Disposal in a Potential Repository at Yucca Mountain  

Science Journals Connector (OSTI)

Performance assessment (PA) simulates the long-term performance of a conceptual geological repository for nuclear waste or the performance of a subsystem such as the engineered barrier system (drifts, waste pa...

W. J. O’Connell; W. L. Bourcier; J. Gansemer…

1998-01-01T23:59:59.000Z

402

Video quality assessment using a statistical model of human visual speed perception  

Science Journals Connector (OSTI)

Motion is one of the most important types of information contained in natural video, but direct use of motion information in the design of video quality assessment algorithms has not...

Wang, Zhou; Li, Qiang

2007-01-01T23:59:59.000Z

403

Stability assessment of a slope under a transformer substation using numerical modelling  

Science Journals Connector (OSTI)

This paper presents an analysis of the deformation mechanism and stability assessment of a slope in Yunnan Province, China. Field investigations indicated that the deformation of the slope was caused by the co...

H. J. Li; F. C. Dai; W. C. Li; L. Xu; H. Min

2011-08-01T23:59:59.000Z

404

Development and assessment of a soot emissions model for aircraft gas turbine engines  

E-Print Network (OSTI)

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 ...

Martini, Bastien

2008-01-01T23:59:59.000Z

405

Game-based assessment: an integrated model for capturing evidence of learning in play  

Science Journals Connector (OSTI)

This paper presents the assessment data aggregator for game environments (ADAGE), a click-stream data framework designed to test whether click-stream data can provide reliable evidence of learning. As digitally-based games become increasingly prevalent ...

Richard Halverson; V. Elizabeth Owen

2014-08-01T23:59:59.000Z

406

A model-based fuzzy set-OWA approach for integrated air pollution risk assessment  

Science Journals Connector (OSTI)

This paper presents a fuzzy set—ordered weighted averaging (FSOWA) approach for the integrated health risk assessment associated with multiple air pollution factors and evaluation criteria. A number of ... the sa...

Baozhen Wang; Zhi Chen

2014-12-01T23:59:59.000Z

407

Development of a new technology product evaluation model for assessing commercialization opportunities using Delphi method and fuzzy AHP approach  

Science Journals Connector (OSTI)

Abstract As the number of new products developed by new technologies has increased, the importance of the commercialization of new technology products has become crucial to manufactures in the successful delivery of valuable new products and services. This study classified success factors for commercialization of new products and analyzed which factors should be primarily considered. Based on the literature review and Delphi method, we identified four decision areas and further prioritized the sixteen factors under a hierarchy model structured by fuzzy AHP (analytic hierarchy process) approach. The FAHP is conducted by 111 R&D and business experts working at the world’s major players in machinery industry; using the priorities of success factors derived by FAHP, we devise an example of commercialization assessment model. The paper drives the assessment initiatives of the new product development in manufactures and provides them with practical implications about the commercialization of new technology product.

Jaemin Cho; Jaeho Lee

2013-01-01T23:59:59.000Z

408

Theory and numerical modeling of the accelerated expansion of laser-ablated materials near a solid surface  

Science Journals Connector (OSTI)

A self-similar theory and numerical hydrodynamic modeling is developed to investigate the effects of dynamic source and partial ionization on the acceleration of the unsteady expansion of laser-ablated material near a solid target surface. The dynamic source effect accelerates the expansion in the direction perpendicular to the target surface, while the dynamic partial ionization effect accelerates the expansion in all directions. The vaporized material during laser ablation provides a nonadiabatic dynamic source at the target surface into the unsteady expanding fluid. For studying the dynamic source effect, the self-similar theory begins with an assumed profile of plume velocity, u=v/vm=?+(1-?)?, where vm is the maximum expansion velocity, ? is a constant, and ?=x/vmt. The resultant profiles of plume density and plume temperature are derived. The relations obtained from the conservations of mass, momentum, and energy, respectively, all show that the maximum expansion velocity is inversely proportional to ?, where 1-? is the slope of plume velocity profile. The numerical hydrodynamic simulation is performed with the Rusanov method and the Newton Raphson method. The profiles and scalings obtained from numerical hydrodynamic modeling are in good agreement with the theory. The dynamic partial ionization requires ionization energy from the heat at the expansion front, and thus reduces the increase of front temperature. The reduction of thermal motion would increase the flow velocity to conserve the momentum. This dynamic partial ionization effect is studied with the numerical hydrodynamic simulation including the Saha equation. With these effects, ? is reduced from its value of conventional free expansion. This reduction on ? increases the flow velocity slope, decreases the flow velocity near the surface, and reduces the thermal motion of plume, such that the maximum expansion velocity is significantly increased over that found from conventional models. The result may provide an explanation for experimental observations of high-expansion front velocities even at low-laser fluence.

K. R. Chen; T. C. King; J. H. Hes; J. N. Leboeuf; D. B. Geohegan; R. F. Wood; A. A. Puretzky; J. M. Donato

1999-09-15T23:59:59.000Z

409

Development of Deposition Models for Paint Application on Surfaces Embedded in  

E-Print Network (OSTI)

robots are widely used for automotive paint ap- plication. The repeatability of the surface finish, along- plying paint is purely robotic, generating trajectories for the robots is largely a human endeavor based to customer rejection [1]. Tra- jectories that are planned for painting robots must yield paint deposition

410

Modelling of c-C2H4O formation on grain surfaces  

Science Journals Connector (OSTI)

......Recently, Ward Price have performed experiments...surface formation of ethylene oxide starting with...the formation of ethylene oxide has been investigated by Ward Price (2011) who studied...quantity of Ward Price (2011). We also...the sensitivity of ethylene oxide fractional......

A. Occhiogrosso; S. Viti; M. D. Ward; S. D. Price

411

Development of a Future Representative Concentration Pathway for Use in the IPCC 5th Assessment Earth System Model Simulations  

SciTech Connect

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.

None

2010-12-29T23:59:59.000Z

412

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

E-Print Network (OSTI)

for models of sediment resuspension Nathan Hawley Great Lakes Environmental Research Laboratory, Ann Arbor 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

NOAA Great Lakes Environmental Research Laboratory, Episodic Events

413

ASSESSMENT OF INTERACTION BETWEEN NORTH PACIFIC ALBACORE, THUNNUS ALALUNGA, FISHERIES BY USE OF A SIMULATION MODEL  

E-Print Network (OSTI)

OF A SIMULATION MODEL P. KLEIBER AND B. BAKER1 ABSTRACT Using a simulation model of a typical year in the North

414

Detecting anthropogenic influences on climate with an atmospheric model forced with observed variations in sea surface temperature  

SciTech Connect

Six ensembles of four simulations with the Hadley Centre atmospheric general circulation model (HADAM2a) have been carried out for late 1948 to the end of 1994 with different specified atmospheric forcing distributions. These simulations are being used to understand the role of different forcing processes in determining the observed climate variations during the second half of the twentieth century. All ensembles started from different initial conditions and were forced with specified global observed monthly sea ice and sea surface temperature distributions using the GISST1.1 data set. The approach used deterministic sampling of observed variations in climate rather than a coupled model. The technique was also different in that it looked at the smaller residual climate signal due to direct anthropogenic over and above those captured in ocean surface temperatures. The results indicate that this method is a useful complement to approaches based on coupled models, aided by the fact that some of the residual climate signals are almost as large as the full signals seen in coupled models, particularly in the stratosphere. 9 refs., 4 figs.

Folland, C.K.; Sexton, D. [Hadley Centre, Bracknell (United Kingdom); Karoly, D. [Monash Univ., Victoria (Australia)] [and others

1997-11-01T23:59:59.000Z

415

Mechanism of methanol synthesis on Cu(100) and Zn/Cu(100) surfaces: Comparative dipped adcluster model study  

SciTech Connect

The mechanism of methanol synthesis from CO{sub 2} and H{sub 2} on Cu(100) and Zn/Cu(100) surfaces was studied using the dipped adcluster model (DAM) combined with ab initio Hartree-Fock (HF) and second-order Moeller-Plesset (MP2) calculations. On clean Cu(100) surface, calculations show that five successive hydrogenations are involved in the hydrogenation of adsorbed CO{sub 2} to methanol, and the intermediates are formate, dioxomethylene, formaldehyde, and methoxy. The rate-limiting step is the hydrogenation of formate to formaldehyde, and the Cu-Cu site is responsible for the reaction on Cu(100). The roles of Zn on Zn/Cu(100) catalyst are to modify the rate-limiting step of the reaction: to lower the activation energies of this step and to stabilize the dioxomethylene intermediate at the Cu-Zn site. The present comparative results indicate that the Cu-Zn site is the active site, which cooperates with the Cu-Cu site to catalyze methanol synthesis on a Cu-based catalyst. Electron transfer from surface to adsorbates is the most important factor in affecting the reactivity of these surface catalysts.

Nakatsuji, Hiroshi; Hu, Zhenming

2000-03-05T23:59:59.000Z

416

The structure and properties of a simple model mixture of amphiphilic molecules and ions at a solid surface  

SciTech Connect

We investigate microscopic structure, adsorption, and electric properties of a mixture that consists of amphiphilic molecules and charged hard spheres in contact with uncharged or charged solid surfaces. The amphiphilic molecules are modeled as spheres composed of attractive and repulsive parts. The electrolyte component of the mixture is considered in the framework of the restricted primitive model (RPM). The system is studied using a density functional theory that combines fundamental measure theory for hard sphere mixtures, weighted density approach for inhomogeneous charged hard spheres, and a mean-field approximation to describe anisotropic interactions. Our principal focus is in exploring the effects brought by the presence of ions on the distribution of amphiphilic particles at the wall, as well as the effects of amphiphilic molecules on the electric double layer formed at solid surface. In particular, we have found that under certain thermodynamic conditions a long-range translational and orientational order can develop. The presence of amphiphiles produces changes of the shape of the differential capacitance from symmetric or non-symmetric bell-like to camel-like. Moreover, for some systems the value of the potential of the zero charge is non-zero, in contrast to the RPM at a charged surface.

Pizio, O., E-mail: pizio@unam.mx [Instituto de Química, Universidad Nacional Autonoma de México, Circuito Exterior, Ciudad Universitaria, 04510 México, D.F. (Mexico); Soko?owski, S., E-mail: stefan.sokolowski@gmail.com [Department for the Modeling of Physico-Chemical Processes, Maria Curie-Sk?odowska University, 20-031 Lublin (Poland); Soko?owska, Z. [Institute of Agrophysics, Polish Academy of Sciences, Do?wiadczalna 4, 20-290 Lublin (Poland)] [Institute of Agrophysics, Polish Academy of Sciences, Do?wiadczalna 4, 20-290 Lublin (Poland)

2014-05-07T23:59:59.000Z

417

Revealing the surface and bulk regimes of isothermal graphene growth on Ni with in situ kinetic measurements and modeling  

SciTech Connect

In situ optical diagnostics are used to reveal the isothermal nucleation and growth mechanisms of graphene on Ni across a wide temperature range (560 C < T < 840 C) by chemical vapor deposition from single, sub-second pulses of acetylene. An abrupt, two-orders of magnitude change in growth times (~ 100s to 1s) is revealed at T = 680 C. Below and above this temperature, similar sigmoidal kinetics are measured and attributed to autocatalytic growth reactions but by two different mechanisms, surface assembly and dissolution/precipitation, respectively. These data are used to develop a simple and general kinetic model for graphene growth that includes the nucleation phase and includes the effects of carbon solubility in metals, describes delayed nucleation, and allows the interpretation of the competition between surface and bulk growth modes. The sharp transition in growth kinetics at T = 680 C is explained by a change in defect site density required for nucleation due to a transition in the carbon-induced mobility of the Ni surface. The easily-implemented optical reflectivity diagnostics and the simple kinetic model described here allow a pathway to optimize the growth of graphene on metals with arbitrary carbon solubility.

Puretzky, Alexander A [ORNL; Merkulov, Igor A [ORNL; Rouleau, Christopher M [ORNL; Eres, Gyula [ORNL; Geohegan, David B [ORNL

2014-01-01T23:59:59.000Z

418

Regional CO2 and latent heat surface fluxes in the Southern Great Plains: Measurements, modeling, and scaling  

SciTech Connect

Characterizing net ecosystem exchanges (NEE) of CO{sub 2} and sensible and latent heat fluxes in heterogeneous landscapes is difficult, yet critical given expected changes in climate and land use. We report here a measurement and modeling study designed to improve our understanding of surface to atmosphere gas exchanges under very heterogeneous land cover in the mostly agricultural U.S. Southern Great Plains (SGP). We combined three years of site-level, eddy covariance measurements in several of the dominant land cover types with regional-scale climate data from the distributed Mesonet stations and Next Generation Weather Radar precipitation measurements to calibrate a land surface model of trace gas and energy exchanges (isotope-enabled land surface model (ISOLSM)). Yearly variations in vegetation cover distributions were estimated from Moderate Resolution Imaging Spectroradiometer normalized difference vegetation index and compared to regional and subregional vegetation cover type estimates from the U.S. Department of Agriculture census. We first applied ISOLSM at a 250 m spatial scale to account for vegetation cover type and leaf area variations that occur on hundred meter scales. Because of computational constraints, we developed a subsampling scheme within 10 km 'macrocells' to perform these high-resolution simulations. We estimate that the Atmospheric Radiation Measurement Climate Research Facility SGP region net CO{sub 2} exchange with the local atmosphere was -240, -340, and -270 gC m{sup -2} yr{sup -1} (positive toward the atmosphere) in 2003, 2004, and 2005, respectively, with large seasonal variations. We also performed simulations using two scaling approaches at resolutions of 10, 30, 60, and 90 km. The scaling approach applied in current land surface models led to regional NEE biases of up to 50 and 20% in weekly and annual estimates, respectively. An important factor in causing these biases was the complex leaf area index (LAI) distribution within cover types. Biases in predicted weekly average regional latent heat fluxes were smaller than for NEE, but larger than for either ecosystem respiration or assimilation alone. However, spatial and diurnal variations of hundreds of W m{sup -2} in latent heat fluxes were common. We conclude that, in this heterogeneous system, characterizing vegetation cover type and LAI at the scale of spatial variation are necessary for accurate estimates of bottom-up, regional NEE and surface energy fluxes.

Riley, W. J.; Biraud, S.C.; Torn, M.S.; Fischer, M.L.; Billesbach, D.P.; Berry, J.A.

2009-08-15T23:59:59.000Z

419

Impact of large scale circulation on European summer surface ozone and consequences for modelling forecast  

E-Print Network (OSTI)

of using day-to-day varying chemical boundary conditions produced by a global chemical weather forecast platform instead of climatological monthly means at the frontiers of a regional model. We performed two- transport models (CTMs) that represent physical and chemical processes controlling ozone concentrations

Menut, Laurent

420

LONG-TERM GLOBAL WATER USE PROJECTIONS USING SIX SOCIOECONOMIC SCENARIOS IN AN INTEGRATED ASSESSMENT MODELING FRAMEWORK  

SciTech Connect

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.

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

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

Using direct normal irradiance models and utility electrical loading to assess benefit of a concentrating solar power plant  

Science Journals Connector (OSTI)

The objective of this paper was to determine if three different direct normal irradiance (DNI) models were sufficiently accurate to determine if concentrating solar power (CSP) plants could meet the utility electrical load. DNI data were measured at three different laboratories in the United States and compared with DNI calculated by three DNI models. In addition, utility electrical loading data were obtained for all three locations. The DNI models evaluated were: the Direct Insolation Simulation Code (DISC), DIRINT, and DIRINDEX. On an annual solar insolation (e.g. kW h/m2) basis, the accuracy of the DNI models at all three locations was within: 7% (DISC), 5% (DIRINT), and 3% (DIRINDEX). During the three highest electrical loading months at the three locations, the monthly accuracy varied from: 0% to 16% (DISC), 0% to 9% (DIRINT), and 0% to 8% (DIRINDEX). At one location different pyranometers were used to measure GHI, and the most expensive pyranometers did not improve the DNI model monthly accuracy. In lieu of actually measuring DNI, using the DIRINT model was felt to be sufficient for assessing whether to build a CSP plant at one location, but use of either the DIRINT or DIRINDEX models was felt to be marginal for the other two locations due to errors in modeling DNI for utility peak electrical loading days – especially for partly cloudy days.

Brian D. Vick; Daryl R. Myers; William E. Boyson

2012-01-01T23:59:59.000Z

422

Mixed integer model for optimizing equipment scheduling and overburden transport in a surface coal mining operation  

SciTech Connect

The lack of available techniques prompted the development of a mixed integer model to optimize the scheduling of equipment and the distribution of overburden in a typical mountaintop removal operation. Using this format, a (0-1) integer model and transportation model were constructed to determine the optimal equipment schedule and optimal overburden distribution, respectively. To solve this mixed integer program, the model was partitioned into its binary and real-valued components. Each problem was successively solved and their values added to form estimates of the value of the mixed integer program. Optimal convergence was indicated when the difference between two successive estimates satisfied some pre-specific accuracy value. The performance of the mixed integer model was tested against actual field data to determine its practical applications. To provide the necessary input information, production data was obtained from a single seam, mountaintop removal operation located in the Appalachian coal field. As a means of analyzing the resultant equipment schedule, the total idle time was calculated for each machine type and each lift location. Also, the final overburden assignments were analyzed by determining the distribution of spoil material for various overburden removal productivities. Subsequent validation of the mixed integer model was conducted in two distinct areas. The first dealt with changes in algorithmic data and their effects on the optimality of the model. The second area concerned variations in problem structure, specifically those dealing with changes in problem size and other user-inputed values such as equipment productivities or required reclamation.

Goodman, G.V.R.

1987-01-01T23:59:59.000Z

423

Refinement of a semi-empirical model for the microwave emissivity of the sea surface as a function of wind speed  

E-Print Network (OSTI)

's sea surface emissivity model. The first change to the model is to the model's treatment of multiple reflections. Multiple reflections are now treated as if the radiation is reflected back into the view path of the microwave sensor. This change lowered...

Kohn, David Jacob

2012-06-07T23:59:59.000Z

424

C. Tavakoli et al.: Dynamics and Modeling of AC Arc on Surface of Ice 1070-9878/06/$20.00 2006 IEEE  

E-Print Network (OSTI)

discharge activities leading to flashover on ice-covered insulator surface is presented. This model takes modeling, arc modeling, outdoor insulation, atmospheric icing. 1 INTRODUCTION OVERHEAD power lines icing deposited on insulators. The study and understanding of arc initiation and propagation

Paris-Sud XI, Université de

425

Phototransformation of Triclosan in Surface Waters:? A Relevant Elimination Process for This Widely Used BiocideLaboratory Studies, Field Measurements, and Modeling  

Science Journals Connector (OSTI)

Phototransformation of Triclosan in Surface Waters:? A Relevant Elimination Process for This Widely Used BiocideLaboratory Studies, Field Measurements, and Modeling ... The phototransformation of the widely used biocide triclosan (5-chloro-2-(2,4-dichlorophenoxy)phenol) was quantified for surface waters using artificial UV light and sunlight irradiation. ... The pH of surface waters, commonly ranging from 7 to 9, determines the speciation of triclosan (pKa = 8.1) and therefore its absorption of sunlight. ...

Céline Tixier; Heinz P. Singer; Silvio Canonica; Stephan R. Müller

2002-07-10T23:59:59.000Z

426

ESD.864 / ESD.936 Systems Modeling and Assessment for Policy, Spring 2010  

E-Print Network (OSTI)

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 ...

Selin, Noelle

427

Tropical Water Vapor and Cloud Feedbacks in Climate Models: A Further Assessment Using Coupled Simulations  

Science Journals Connector (OSTI)

By comparing the response of clouds and water vapor to ENSO forcing in nature with that in Atmospheric Model Intercomparison Project (AMIP) simulations by some leading climate models, an earlier evaluation of tropical cloud and water vapor ...

De-Zheng Sun; Yongqiang Yu; Tao Zhang

2009-03-01T23:59:59.000Z

428

Coupling GIS and LCA for biodiversity assessments of land use: Part 1: Inventory modeling  

E-Print Network (OSTI)

scenarios were developed with GIS modeling. Current land use0170-9 LAND USE IN LCA Coupling GIS and LCA for biodiversityGeographic information systems (GIS) are adept at modeling

Geyer, Roland; Stoms, David M.; Lindner, Jan P.; Davis, Frank W.; Wittstock, Bastian

2010-01-01T23:59:59.000Z

429

Assessing the prospective environmental impacts of photovoltaic systems based on a simplified LCA model  

E-Print Network (OSTI)

Assessing the prospective environmental impacts of photovoltaic systems based on a simplified LCA cycle analysis (LCA). However, LCA requires the collection of a large amount of data and is thus time-consuming. Besides, LCA results found in the literature corresponding to the photovoltaic energy pathway show a large

Paris-Sud XI, Université de

430

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

E-Print Network (OSTI)

multi-objective optimization model to characterize the tradeoffs between water supply shortages and fish 10 population capacity in a stream on the west-slope of the Sierra Nevada mountain range. Harman and Stewardson (2005) evaluated a range...

Pauls, Mark

2014-03-18T23:59:59.000Z

431

Modeling of the surface static displacements and fault plane slip for the 1979 Imperial Valley earthquake  

SciTech Connect

Three-dimensional finite element modeling techniques are used to synthesize geodetic and seismological results for 1979 Imperial Valley earthquake. The strategy pursued consists of two principal steps. In the first step, the seismologically-derived coseismic fault slip is taken as a function of position in the fault plane and is applied directly to the three-dimensional dislocation model. In the second step, a physical model of stresses and constitutive parameters is perturbed so as to reproduce the observed fault slip. Hence, the principal features of the coseismic slip pattern are explained by a stress-driven fault model in which: (1) a spatially unresolved asperity is found equivalent to a stress drop of 18 MPa averaged over an area of 15 sq km, and (2) driving stress is essentially absent on the fault segment overlapping the 1940 earthquake rupture zone. 24 references.

Slade, M.A.; Lyzenga, G.A.; Raefsky, A.

1984-12-01T23:59:59.000Z

432

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

E-Print Network (OSTI)

though, that nutrient limitation coupled with fluid motion may play a key role as a physical control. Under this model, competitions of nutrients were setup among growing microbial communities, which later evolve into specially arranged, 3D mats. However...

Patel, Harsh Jay

2013-09-27T23:59:59.000Z

433

Modeling the Atmospheric Boundary Layer Wind Response to Mesoscale Sea Surface Temperature Perturbations  

Science Journals Connector (OSTI)

The wind speed response to mesoscale SST variability is investigated over the Agulhas Return Current region of the Southern Ocean using the Weather Research and Forecasting (WRF) Model and the U.S. Navy Coupled Ocean–Atmosphere Mesoscale ...

Natalie Perlin; Simon P. de Szoeke; Dudley B. Chelton; Roger M. Samelson; Eric D. Skyllingstad; Larry W. O’Neill

2014-11-01T23:59:59.000Z

434

Bias Correction and Bayesian Model Averaging for Ensemble Forecasts of Surface Wind Direction  

Science Journals Connector (OSTI)

Wind direction is an angular variable, as opposed to weather quantities such as temperature, quantitative precipitation, or wind speed, which are linear variables. Consequently, traditional model output statistics and ensemble postprocessing ...

Le Bao; Tilmann Gneiting; Eric P. Grimit; Peter Guttorp; Adrian E. Raftery

2010-05-01T23:59:59.000Z

435

Metabolic modeling for the deposition of transuranic nuclides on bone surfaces  

E-Print Network (OSTI)

The study of toxic effects of plutonium was begun by Dr. Glenn Seaborg in 1950 with a twenty year project. Although many effects of plutonium have been previously discovered during various studies, an accurate metabolic model for the transport...

Halter, Donald Anthony

1997-01-01T23:59:59.000Z

436

Paired chiral spin liquid with a Fermi surface in S=1 model on the triangular lattice  

E-Print Network (OSTI)

Motivated by recent experiments on Ba[subscript 3]NiSb[subscript 2]O[subscript 9], we investigate possible quantum spin liquid ground states for spin S=1 Heisenberg models on the triangular lattice. We use variational Monte ...

Bieri, Samuel

437

Sisal Fibers: Surface Chemical Modification Using Reagent Obtained from a Renewable Source; Characterization of Hemicellulose and Lignin as Model Study  

Science Journals Connector (OSTI)

Sisal Fibers: Surface Chemical Modification Using Reagent Obtained from a Renewable Source; Characterization of Hemicellulose and Lignin as Model Study ... Instituto de Química de São Carlos, Universidade de São Paulo, USP, C.P. 780, CEP 13560-970 São Carlos, SP, Brazil, and Université Bordeaux 1, US2B, UMR 5103 CNRS-INRA-UBx1, F-33405 Talence Cedex, France ... The main advantage of lignocellulosic fibers upon their mineral counterpart is their environmental friendliness, due, for instance, to the CO2 neutral life cycle and possibility of incineration for energy recovery after disposal (3). ...

Jackson D. Megiatto, Jr.; William Hoareau; Christian Gardrat; Elisabete Frollini; Alain Castellan

2007-09-15T23:59:59.000Z

438

Doping dependence of Fermi surface in high-Tc cuprates studied by model Hartree-Fock calculations  

Science Journals Connector (OSTI)

We have investigated doping dependence of Fermi surface, band dispersion, and magnetic structure in high-Tc cuprates by using Hartree-Fock calculation on a Cu 3d–O 2p tight-binding model. In the slightly electron-doped regime, electron pockets emerge around (?,0), which agrees with the photoemission study of Nd2-xCexCuO4. In the slightly hole-doped regime, hole pockets emerge around (?/2,?/2), which might explain the recent photoemission result of Ca2-xNaxCuO2Cl2.

D. Asakura and T. Mizokawa

2003-09-23T23:59:59.000Z

439

D-optimal design for Rapid Assessment Model of CO2 flooding in high water cut oil reservoirs  

Science Journals Connector (OSTI)

Abstract Most of major oilfields in China have reached high water cut stage, but still, they contribute to more than 70% of domestic oil production. How to extract more oil from mature oilfields has become a hot topic in petroleum engineering. Carbon dioxide flooding is a win–win strategy because it can enhance oil recovery and simultaneously reduce CO2 emissions into the atmosphere. In order to evaluate the potentials of CO2 flooding in high water cut oil reservoirs, various 3-D heterogeneous geological models were built based on Guan 104 fault block in Dagang Oilfield to perform reservoir simulations. The D-optimal design was applied to build and verify the Rapid Assessment Model of CO2 flooding in high water cut oil reservoirs. Five quantitative variables were considered, including average horizontal permeability, permeability variation coefficient, ratio of vertical to horizontal permeability, net thickness of formation and percentage of recoverable reserves by water flooding. The process of weighting emphasized the contributions of linear terms, quadratic terms and first-order interactions of five quantitative parameters to improved recovery factor and Net Present Value of CO2 flooding. Using the Rapid Assessment Model of CO2 flooding in high water cut oil reservoirs, significant first-order interactions were sorted out and type curves were established and analyzed for the evaluation of technical and economic efficiency of CO2 flooding in high water cut oil reservoirs. Aimed at oil reservoirs with the similar geological conditions and fluid properties as Guan 104 fault block, the Rapid Assessment Model and type curves of CO2 flooding in high water cut oil reservoirs can be applied to predict improved recovery factor and Net Present Value of water-alternating-CO2 flooding at different conditions of reservoir parameters and development parameter. The approach could serve as a guide for the application and spread of CO2-EOR projects.

Zhaojie Song; Zhiping Li; Chunsheng Yu; Jirui Hou; Mingzhen Wei; Baojun Bai; Yunpeng Hu

2014-01-01T23:59:59.000Z

440

numerical models & information Systems, Nice: France (2013)" Environmental impact for offshore wind farms: Geolocalized Life Cycle Assessment (LCA) approach  

E-Print Network (OSTI)

Abstract. This paper presents an approach for Environmental Impact Assessment through the use of geolocalized LCA approach, for fixed and floating offshore wind farms. This work was undertaken within the EUsponsored EnerGEO project, aiming at providing a versatile modeling platform for stakeholders allowing calculation, forecasting and monitoring of environmental impacts of different sources of energy. This paper described the geolocalized LCA approach, and its use for the evaluation of environmental impacts of wind energy. The effects of offshore wind farms on global environnemental impacts are evaluated though the LCA approach. It takes into account the type of wind farm, the construction phase, all technical aspects, the operation and maintenance scheme and the decommissioning. It also includes geolocalized information such as wind resources, bathymetry, accessibility … Environmental impact parameters are accessible through a web service helping the decision makers in assessing the environnemental impacts. 1

Catherine Guermont; Lionel Ménard; Isabelle Blanc

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "models assessing surface" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Development of custom fire behavior fuel models from FCCS fuelbeds for the Savannah River fuel assessment project.  

SciTech Connect

The purpose of this project is to create fire behavior fuel models that replicate the fire behavior characteristics (spread rate and fireline intensity) produced by 23 candidate FCCS fuelbeds developed for the Savannah River National Wildlife Refuge. These 23 fuelbeds were created by FERA staff in consultation with local fuel managers. The FCCS produces simulations of surface fire spread rate and flame length (and therefore fireline intensity) for each of these fuelbeds, but it does not produce maps of those fire behavior characteristics or simulate fire growth—those tasks currently require the use of the FARSITE and/or FlamMap software systems. FARSITE and FlamMap do not directly use FCCS fuelbeds, but instead use standard or custom fire behavior fuel models to describe surface fuel characteristics for fire modeling. Therefore, replicating fire growth and fire behavior potential calculations using FCCS?simulated fire characteristics requires the development of custom fuel models that mimic, as closely as possible, the fire behavior characteristics produced by the FCCS for each fuelbed, over a range of fuel moisture and wind speeds.

Scott, Joe, H.

2009-07-23T23:59:59.000Z

442

Evaluation of cloud fraction and its radiative effect simulated by IPCC AR4 global models against ARM surface observations  

SciTech Connect

Cloud Fraction (CF) is the dominant modulator of radiative fluxes. In this study, we evaluate CF simulations in the IPCC AR4 GCMs against ARM ground measurements, with a focus on the vertical structure, total amount of cloud and its effect on cloud shortwave transmissivity, for both inter-model deviation and model-measurement discrepancy. Our intercomparisons of three CF or sky-cover related dataset reveal that the relative differences are usually less than 10% (5%) for multi-year monthly (annual) mean values, while daily differences are quite significant. The results also show that the model-observation and the inter-model deviations have a similar magnitude for the total CF (TCF) and the normalized cloud effect, and they are twice as large as the surface downward solar radiation and cloud transmissivity. This implies that the other cloud properties, such as cloud optical depth and height, have a similar magnitude of disparity to TCF among the GCMs, and suggests that a better agreement among the GCMs in solar radiative fluxes could be the result of compensating errors in either cloud vertical structure, cloud optical depth or cloud fraction. Similar deviation pattern between inter-model and model-measurement suggests that the climate models tend to generate larger bias against observations for those variables with larger inter-model deviation. The simulated TCF from IPCC AR4 GCMs are very scattered through all seasons over three ARM sites: Southern Great Plains (SGP), Manus, Papua New Guinea and North Slope of Alaska (NSA). The GCMs perform better at SGP than at Manus and NSA in simulating the seasonal variation and probability distribution of TCF; however, the TCF in these models is remarkably underpredicted and cloud transmissivity is less susceptible to the change of TCF than the observed at SGP. Much larger inter-model deviation and model bias are found over NSA than the other sites in estimating the TCF, cloud transmissivity and cloud-radiation interaction, suggesting that the Arctic region continues to challenge cloud simulations in climate models. Most of the GCMs tend to underpredict CF and fail to capture the seasonal variation of CF at middle and low levels in the tropics. The high altitude CF is much larger in the GCMs than the observation and the inter-model variability of CF also reaches maximum at high levels in the tropics. Most of the GCMs tend to underpredict CF by 50-150% relative to the measurement average at low and middle levels over SGP. While the GCMs generally capture the maximum CF in the boundary layer and vertical variability, the inter-model deviation is largest near surface over the Arctic. The internal variability of CF simulated in ensemble runs with the same model is very minimal.

Qian, Yun; Long, Charles N.; Wang, Hailong; Comstock, Jennifer M.; McFarlane, Sally A.; Xie, Shaocheng

2012-02-17T23:59:59.000Z

443

Thermal Fluctuations in the Structure of Naturally Chiral Pt Surfaces  

SciTech Connect

The intrinsic chirality of metal surfaces with kinked steps (e.g. Pt(643)) endows them with enantiospecific adsorption properties (D. S. Shell, Langmuir, 14, 1998, 862). To understand these properties quantitatively the impact of thermally-driven step wandering must be assessed. The authors derive a lattice-gas model of step motion on Pt(111) surfaces using diffusion barriers from Density Functional Theory. This model is used to examine thermal fluctuations of straight and kinked steps.

ASTHAGIRI,ARAVIND; FEIBELMAN,PETER J.; SHOLL,DAVID S.

2000-07-20T23:59:59.000Z

444

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

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.

Subin, Z.M.; Riley, W.J.; Kueppers, L.M.; Jin, J.; Christianson, D.S.; Torn, M.S.

2010-11-01T23:59:59.000Z

445

Surface Complexation of Neptunium(V) onto Whole Cells and Cell Components of Shewanella alga: Modeling and Experimental Study  

SciTech Connect

We systematically quantified surface complexation of Np(V) onto whole cells, cell wall, and extracellular polymeric substances (EPS) of Shewanella alga strain BrY. We first performed acid and base titrations and used the mathematical model FITEQL to estimate the concentrations and deprotonation constants of specific surface functional groups. Deprotonation constants most likely corresponded to a carboxyl group not associated with amino acids (pK{sub a} {approx} 5), a phosphoryl site (pK{sub a} {approx} 7.2), and an amine site (pK{sub a} > 10). We then carried out batch sorption experiments with Np(V) and each of the S. alga components as a function of pH. Since significant Np(V) sorption was observed on S. alga whole cells and its components in the pH range 2-5, we assumed the existence of a fourth site: a low-pK{sub a} carboxyl site (pK{sub a} {approx} 2.4) that is associated with amino acids. We used the SPECIATE submodel of the biogeochemical model CCBATCH to compute the stability constants for Np(V) complexation to each surface functional group. The stability constants were similar for each functional group on S. alga bacterial whole cells, cell walls, and EPS, and they explain the complicated sorption patterns when they are combined with the aqueous-phase speciation of Np(V). For pH < 8, the aquo NpO{sub 2}{sup +} species was the dominant form of Np(V), and its log K values for the low-pK{sub a} carboxyl, mid-pK{sub a} carboxyl, and phosphoryl groups were 1.8, 1.8, and 2.5-3.1, respectively. For pH greater than 8, the key surface ligand was amine > XNH{sub 3}{sup +}, which complexed with NpO{sub 2}(CO{sub 3}){sub 3}{sup 5-}. The log K for NpO{sub 2}(CO{sub 3}){sub 3}{sup 5-} complexed onto the amine groups was 3.1-3.9. All of the log K values are similar to those of Np(V) complexes with aqueous carboxyl and N-containing carboxyl ligands. These results help quantify the role of surface complexation in defining actinide-microbiological interactions in the subsurface.

Deo, Randhir P.; Songkasiri, Warinthorn; Rittmann, Bruce E.; Reed, Donald T. (King Mongkut); (AZU); (LANL)

2012-04-30T23:59:59.000Z

446

New models for wind noise measured in a flat surface under turbulent flow.  

Science Journals Connector (OSTI)

We have previously developed models for predicting the power spectral density of the wind noisepressuremeasured in a flat plate outdoors from the measured power spectral density of the turbulence and the measured wind velocity profile above the plate [Yu et al. Proceedings of NCAD 2008 NoiseCon2008?ASME NCAD]. Recently we have corrected an error in the model for the logarithmic profile wind velocity gradient results and have developed an improved integration method. Also we have developed a prediction for arbitrary wind velocity profiles using the previous single exponential model. Typical results comparing our predictions with our measurements are presented and analyzed. A simple algebraic fit to the prediction for the logarithmic profile fit form is also provided for use by others. [Research supported by the U.S. Army TACOM?ARDEC at Picatinny Arsenal NJ.

2009-01-01T23:59:59.000Z

447

Modeling  

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

sion effects. We show the result of a test case, and compare it to the result without surface tension. The model describes droplet formation nicely. Application The ARRA-funded...

448

Agricultural Chemical Movement through a Field-Size Watershed in Iowa:? Surface Hydrology and Nitrate Losses in Discharge  

Science Journals Connector (OSTI)

Agricultural Chemical Movement through a Field-Size Watershed in Iowa:? Surface Hydrology and Nitrate Losses in Discharge ... In this paper, we illustrate another aspect of the “water quality profile” conceptual model (4) for assessing impacts of farming systems using an analysis of the surface hydrology and nitrate distribution in surface runoff, headcut seepage, and basin drainage from a high relief landscape. ... Surface runoff resulting from snowmelt occurs whenever solar-radiated heat penetrates the snow and heats the soil surface beneath it. ...

Thomas R. Steinheimer; Kenwood D. Scoggin; Larry A. Kramer

1998-02-28T23:59:59.000Z

449

CCS, Nuclear Power and Biomass An Assessment of Option Triangle under Global Warming Mitigation Policy by an Integrated Assessment Model MARIA-23  

Science Journals Connector (OSTI)

Abstract It is well understood that the global climate change caused by the increase of greenhouse gas (GHG) emission would be a serious barrier towards the sustainable development. Nuclear power, CCS and biomass have been regarded as the major options in the GHG mitigation policy. However, since the social acceptance of nuclear power expansion has seriously been changed after the gigantic earthquake on March 11, 2011 followed by the Fukushima Daiichi nuclear power station accident, the energy policy makers are forced to consider both the global warming and the decline of nuclear power simultaneously. This study attempts to address the following key questions: (1) how much additional costs or decline of production will be needed when nuclear power expansion is limited under the GHG emission control policies and (2) to what extent the potential of the biomass and CCS could compensate for the nuclear power reductions. We expand an integrated assessment model, MARIA-23 (Multiregional Approach for Resource and Industry Allocation) to deal with the CCS options and biomass options taking into account the additional carbon emission by cultivation. The simulation results show the interrelationships of the carbon mitigation contributions of the above three major options under various scenarios.

Shunsuke Mori; Keisuke Miyaji; Kazuhisa Kamegai

2013-01-01T23:59:59.000Z

450

MA3T Model Application at ORNL Assesses the Future of Fuel Cell...  

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

has developed a model for simulating the market potential of fuel cell electric vehicles (FCEV) and challenges to achieving success over time, including competition with...