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Note: This page contains sample records for the topic "regional dynamics model" from the National Library of EnergyBeta (NLEBeta).
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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

Regional Dynamics Model (REDYN) | Open Energy Information  

Open Energy Info (EERE)

Regional Dynamics Model (REDYN) Regional Dynamics Model (REDYN) Jump to: navigation, search Tool Summary Name: REDYN Agency/Company /Organization: Regional Dynamics Inc. Sector: Energy Phase: Determine Baseline, "Evaluate Options and Determine Feasibility" is not in the list of possible values (Bring the Right People Together, Create a Vision, Determine Baseline, Evaluate Options, Develop Goals, Prepare a Plan, Get Feedback, Develop Finance and Implement Projects, Create Early Successes, Evaluate Effectiveness and Revise as Needed) for this property., Develop Goals Topics: Market analysis, Policies/deployment programs, Co-benefits assessment, - Macroeconomic Resource Type: Software/modeling tools User Interface: Desktop Application Website: www.regionaldynamics.com/

2

Critical region for an Ising model coupled to causal dynamical triangulations  

E-Print Network [OSTI]

A lower and an upper bound are established upon a critical curve for the (annealed) Ising model coupled to two-dimensional causal dynamical triangulations. Using the Fortuin-Kasteleyn (FK) representation of quantum Ising models via path integrals, we determine a region in the quadrant of parameters $\\beta, \\mu>0$ where the critical curve can be located. Moreover, this approach serves to outline a region where the infinite-volume Gibbs measure exist and is unique and a region where the finite-volume Gibbs measure has no weak limit. We also provide lower and upper bounds for the infinite-volume free energy.

José Cerda Hernández

2014-02-13T23:59:59.000Z

3

Modeling the Dynamics of Desakota Regions: Global - Local Nexus in the Taipei Metropolitan Area  

E-Print Network [OSTI]

develops a GIS-based CA framework based on the desakota model to not only simulate the unique urbanization processes in Asia but also integrate the influence of globalization into Asian urban dynamics. Three approaches are developed in the CA simulation: 1...

Wu, Bing-Sheng

2010-10-12T23:59:59.000Z

4

A phenomenological model of dynamical arrest of electron transfer in solvents in the glass-transition region  

E-Print Network [OSTI]

A phenomenological model of dynamical arrest of electron transfer in solvents in the glass 2004; published online 17 February 2005 A phenomenological model of electron transfer reactions-acceptor energy gaps dashed line in Fig. 1 differs from the equilibrium distribution. The present phenomenological

Matyushov, Dmitry

5

AVESTAR® - Dynamic Modeling  

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

Dynamic Modeling Dynamic Modeling The AVESTAR team is pursuing research on the dynamic modeling and simulation of advanced energy systems ranging from power plants to power grids. Dynamic models provide a continuous view of energy systems in action by calculating their transient behavior over time. Plant-wide Models For power plants, dynamic models are used to analyze a wide variety of operating scenarios, including normal base load operation, startup, shutdown, feedstock switchovers, cycling, and load-following. Dynamic process and control models are also essential for analyzing plant responses to setpoint changes and disturbances, as well as malfunctions and abnormal situations. Other applications of plant-wide dynamic models include controllability and operational flexibility analyses, environmental studies, safety evaluations, and risk mitigation.

6

Regional Climate Modeling: Progress, Challenges, and Prospects  

SciTech Connect (OSTI)

Regional climate modeling with regional climate models (RCMs) has matured over the past decade and allows for meaningful utilization in a broad spectrum of applications. In this paper, latest progresses in regional climate modeling studies are reviewed, including RCM development, applications of RCMs to dynamical downscaling for climate change assessment, seasonal climate predictions and climate process studies, and the study of regional climate predictability. Challenges and potential directions of future research in this important area are discussed, with the focus on those to which less attention has been given previously, such as the importance of ensemble simulations, further development and improvement of regional climate modeling approach, modeling extreme climate events and sub-daily variation of clouds and precipitation, model evaluation and diagnostics, applications of RCMs to climate process studies and seasonal predictions, and development of regional earth system models. It is believed that with both the demonstrated credibility of RCMs’ capability in reproducing not only monthly to seasonal mean climate and interannual variability but also the extreme climate events when driven by good quality reanalysis and the continuous improvements in the skill of global general circulation models (GCMs) in simulating large-scale atmospheric circulation, regional climate modeling will remain an important dynamical downscaling tool for providing the needed information for assessing climate change impacts and seasonal climate predictions, and a powerful tool for improving our understanding of regional climate processes. An internationally coordinated effort can be developed with different focuses by different groups to advance regional climate modeling studies. It is also recognized that since the final quality of the results from nested RCMs depends in part on the realism of the large-scale forcing provided by GCMs, the reduction of errors and improvement in physics parameterizations in both GCMs and RCMs remain a priority for climate modeling community.

Wang, Yuqing; Leung, Lai R.; McGregor, John L.; Lee, Dong-Kyou; Wang, Wei-Chyung; Ding, Yihui; Kimura, Fujio

2004-12-01T23:59:59.000Z

7

Models of Dynamical Supersymmetry Breaking  

E-Print Network [OSTI]

We review a class of models of dynamical supersymmetry breaking, and give a unified description of these models.

Lisa Randall

1997-06-23T23:59:59.000Z

8

Dynamic Modelling, Measurement and  

E-Print Network [OSTI]

Dynamic Modelling, Measurement and Control of Co-rotating Twin-Screw Extruders Justin Rae Elsey, B;Summary Co-rotating twin-screw extruders are unique and versatile machines that are used widely that these extruders are currently being optimally utilised. The most signi cant improvement to the eld of twin-screw

Fernandez, Thomas

9

A computational fluid dynamics model for wind simulation: model implementation and experimental validation  

Science Journals Connector (OSTI)

To provide physically based wind modelling for wind erosion research at regional scale, a 3D computational fluid dynamics (CFD) wind model was developed. The model was programmed ... analysis and modelling tool (...

Zhuo-dong Zhang; Ralf Wieland; Matthias Reiche…

2012-04-01T23:59:59.000Z

10

Price dynamics of crude oil and the regional ethylene markets  

Science Journals Connector (OSTI)

This paper is the first attempt to investigate: (i) is the crude oil (WTI) price significantly related to the regional ethylene prices in the Naphtha intensive ethylene markets of the Far East, North West Europe, and the Mediterranean? (ii) What drives the regional ethylene prices? The paper is motivated by the recent and growing debate on the lead-lag relationship between crude oil and ethylene prices. Our findings, based on the long-run structural modelling approach of Pesaran and Shin, and subject to the limitations of the study, tend to suggest: (i) crude oil (WTI) price is cointegrated with the regional ethylene prices (ii) our within-sample error-correction model results tend to indicate that although the ethylene prices in North West Europe and the Mediterranean were weakly endogenous, the Far East ethylene price was weakly exogenous both in the short and long term. These results are consistent, during most of the period under review (2000.1–2006.4) with the surge in demand for ethylene throughout the Far East, particularly in China and South Korea. However, during the post-sample forecast period as evidenced in our variance decompositions analysis, the emergence of WTI as a leading player as well, is consistent with the recent surge in WTI price (fuelled mainly, among others, by the strong hedging activities in the WTI futures/options and refining tightness) reflecting the growing importance of input cost in determining the dynamic interactions of input and product prices.

Mansur Masih; Ibrahim Algahtani; Lurion De Mello

2010-01-01T23:59:59.000Z

11

GLOBAL DYNAMICS OF SUBSURFACE SOLAR ACTIVE REGIONS  

SciTech Connect (OSTI)

We present three-dimensional numerical simulations of a magnetic loop evolving in either a convectively stable or unstable rotating shell. The magnetic loop is introduced into the shell in such a way that it is buoyant only in a certain portion in longitude, thus creating an {Omega}-loop. Due to the action of magnetic buoyancy, the loop rises and develops asymmetries between its leading and following legs, creating emerging bipolar regions whose characteristics are similar to those of observed spots at the solar surface. In particular, we self-consistently reproduce the creation of tongues around the spot polarities, which can be strongly affected by convection. We further emphasize the presence of ring-shaped magnetic structures around our simulated emerging regions, which we call 'magnetic necklace' and which were seen in a number of observations without being reported as of today. We show that those necklaces are markers of vorticity generation at the periphery and below the rising magnetic loop. We also find that the asymmetry between the two legs of the loop is crucially dependent on the initial magnetic field strength. The tilt angle of the emerging regions is also studied in the stable and unstable cases and seems to be affected both by the convective motions and the presence of a differential rotation in the convective cases.

Jouve, L. [UPS-OMP, Institut de Recherche en Astrophysique et Planetologie, Universite de Toulouse CNRS, 14 Avenue Edouard Belin, F-31400 Toulouse (France)] [UPS-OMP, Institut de Recherche en Astrophysique et Planetologie, Universite de Toulouse CNRS, 14 Avenue Edouard Belin, F-31400 Toulouse (France); Brun, A. S. [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, IRFU/SAp, F-91191 Gif sur Yvette (France)] [Laboratoire AIM, CEA/DSM-CNRS-Universite Paris Diderot, IRFU/SAp, F-91191 Gif sur Yvette (France); Aulanier, G., E-mail: ljouve@irap.omp.eu [LESIA, Observatoire de Paris, CNRS, UPMC, Universite Paris-Diderot, 5 Place Jules Janssen, F-92190 Meudon Cedex (France)

2013-01-01T23:59:59.000Z

12

Regions in Energy Market Models  

SciTech Connect (OSTI)

This report explores the different options for spatial resolution of an energy market model--and the advantages and disadvantages of models with fine spatial resolution. It examines different options for capturing spatial variations, considers the tradeoffs between them, and presents a few examples from one particular model that has been run at different levels of spatial resolution.

Short, W.

2007-02-01T23:59:59.000Z

13

Predictive Models of Forest Dynamics  

Science Journals Connector (OSTI)

...currently highly uncertain (Fig. 1), making vegetation dynamics one of the largest sources of uncertainty in Earth system models. Reducing this uncertainty requires work on several fronts. For example, physiological parameters need to be...

Drew Purves; Stephen Pacala

2008-06-13T23:59:59.000Z

14

Model system for slow dynamics  

Science Journals Connector (OSTI)

Systems whose dynamics are described by a quasilogarithmic or stretched-exponential time dependence are usually fitted by models which use disorder to create a distribution of relaxation times. Here we describe a model which decays slowly towards equilibrium but does not require disorder to provide the slow dynamics. The model consists of a spin system with the spins interacting via the dipole-dipole interaction. The model is able to replicate the more pronounced features observed in the magnetization decay of magnetic systems and high-temperature superconductors.

D. K. Lottis; R. M. White; E. Dan Dahlberg

1991-07-15T23:59:59.000Z

15

Modeling-Computer Simulations At Yellowstone Region (Laney, 2005) | Open  

Open Energy Info (EERE)

Laney, 2005) Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Yellowstone Region (Laney, 2005) Exploration Activity Details Location Yellowstone Caldera Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful regional reconnaissance DOE-funding Unknown Notes Localized Strain as a Discriminator of Hidden Geothermal Systems, Vasco and Foxall, 2005. Recent work has focused on (1) collaborating with Alessandro Ferretti to use Permanent Scatterer (PS) InSAR data to infer strain at depth, (2) working with Lane Johnson to develop a dynamic faulting model, and (3) acquiring InSAR data for the region surrounding the Dixie Valley fault zone in collaboration with Dr. William Foxall of LLNL. The InSAR data

16

Modeling Molecular Dynamics from Simulations  

SciTech Connect (OSTI)

Many important processes in biology occur at the molecular scale. A detailed understanding of these processes can lead to significant advances in the medical and life sciences. For example, many diseases are caused by protein aggregation or misfolding. One approach to studying these systems is to use physically-based computational simulations to model the interactions and movement of the molecules. While molecular simulations are computationally expensive, it is now possible to simulate many independent molecular dynamics trajectories in a parallel fashion by using super- or distributed- computing methods such as Folding@Home or Blue Gene. The analysis of these large, high-dimensional data sets presents new computational challenges. In this seminar, I will discuss a novel approach to analyzing large ensembles of molecular dynamics trajectories to generate a compact model of the dynamics. This model groups conformations into discrete states and describes the dynamics as Markovian, or history-independent, transitions between the states. I will discuss why the Markovian state model (MSM) is suitable for macromolecular dynamics, and how it can be used to answer many interesting and relevant questions about the molecular system. I will also discuss many of the computational and statistical challenges in building such a model, such as how to appropriately cluster conformations, determine the statistical reliability, and efficiently design new simulations.

Hinrichs, Nina Singhal (University of Chicago) [University of Chicago

2009-01-28T23:59:59.000Z

17

Development of a Dynamic DOE Calibration Model  

Broader source: Energy.gov [DOE]

A dynamic heavy duty diesel engine model was developed. The model can be applied for calibration and control system optimization.

18

Dynamical model of Ising spins  

Science Journals Connector (OSTI)

A two-dimensional dynamical model of Ising spins is introduced. Since we were not able to define energy in our system, we introduced an object called the disagreement function. This function controls the dynamics—minimizing it locally we decide upon spin flipping. Amazingly, local minimization of the disagreement function can lead to an increase of its global value. We present the phase diagram of the system and show that exactly the same initial conditions can lead the system to one of several, completely different final steady states.

Katarzyna Sznajd-Weron

2004-09-30T23:59:59.000Z

19

Regional Economic Models, Inc. (REMI) Model | Open Energy Information  

Open Energy Info (EERE)

Regional Economic Models, Inc. (REMI) Model Regional Economic Models, Inc. (REMI) Model Jump to: navigation, search LEDSGP green logo.png FIND MORE DIA TOOLS This tool is part of the Development Impacts Assessment (DIA) Toolkit from the LEDS Global Partnership. Tool Summary LAUNCH TOOL Name: REMI Agency/Company /Organization: Regional Economic Models Inc. Sector: Energy Focus Area: Transportation Phase: Determine Baseline, Develop Goals Topics: Baseline projection, GHG inventory, Pathways analysis Resource Type: Software/modeling tools User Interface: Desktop Application Complexity/Ease of Use: Moderate Website: www.remi.com/ Cost: Paid References: http://www.remi.com/index.php?page=overview&hl=en_US Related Tools Job and Economic Development Impact Models (JEDI) The Integrated Environmental Strategies Handbook: A Resource Guide for Air Quality Planning

20

Does High[Plasma]-Beta Dynamics "Load" Active Regions?  

E-Print Network [OSTI]

Using long-duration observations in the He II 304 Angstrom passband of the Solar and Heliospheric Observatory (SOHO) Extreme-ultraviolet Imaging Telescope (EIT) we investigate the spatial and temporal appearance of impulsive intensity fluctuations in the pixel light curves. These passband intensity fluctuations come from plasma emitting in the chromosphere, transition region and lowest portions of the corona. We see that they are spatially tied to the supergranular scale and that their rate of occurrence is tied to the unsigned imbalance of the magnetic field in which they are observed. The signature of the fluctuations (in space and time) is consistent with their creation by magnetoconvection forced reconnection that is driven by the flow field in the high-beta plasma. The signature of the intensity fluctuations around an active region suggest that the bulk of the mass and energy supplied into the active region complex observed in the hotter coronal plasma is supplied by this process, dynamically forcing the looped structure from beneath.

Scott W. McIntosh

2007-02-04T23:59:59.000Z

Note: This page contains sample records for the topic "regional dynamics model" 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

Dynamics of Nucleation in the Ising Model  

Science Journals Connector (OSTI)

Dynamics of Nucleation in the Ising Model† ... Reactive pathways to nucleation in a three-dimensional Ising model at 60% of the critical temperature are studied using transition path sampling of single spin flip Monte Carlo dynamics. ... The application focuses on the simplest example of nucleation, that of a supercooled Ising model. ...

Albert C. Pan; David Chandler

2004-09-28T23:59:59.000Z

22

Modeling System Development for the Evaluation of Dynamic Air Quality  

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

Modeling System Development for the Evaluation of Dynamic Air Quality Modeling System Development for the Evaluation of Dynamic Air Quality Impacts of DER Speaker(s): Robert Van Buskirk Date: January 30, 2003 - 12:00pm Location: Bldg. 90 Seminar Host/Point of Contact: Kristina LaCommare A critical challenge for the atmospheric sciences is to understand the anthropogenic impacts on atmospheric chemistry over spatial scales ranging from the urban to the regional, and ultimately to the global, and over corresponding time scales ranging from minutes to weeks and ultimately annual trends. A similar challenge for energy policymakers is to integrate an understanding of impact dynamics into the economic dynamics of energy supply and demand. The challenges of dynamic analysis of emissions impacts from the energy sector have substantially increased with a new

23

Impact of the solar wind dynamic pressure on the Region 2 field-aligned currents  

E-Print Network [OSTI]

Impact of the solar wind dynamic pressure on the Region 2 field-aligned currents S. Nakano,1,2 G and the solar wind dynamic pressure is investigated using magnetic field data from Defense Meteorological in the magnetosphere varies with the solar wind dynamic pressure. Therefore, we can expect that the Region 2 currents

Higuchi, Tomoyuki

24

Dynamic competition model for construction contractors  

E-Print Network [OSTI]

competition, a system dynamics model has been developed based on the identified concepts. In this model, there are three managerial areas in which a contractor makes policy: 1) markup; 2) marketing; and 3) capacity. Each firm's backlog level is considered...

Kim, Hyung Jin

2012-06-07T23:59:59.000Z

25

Conceptual aircraft dynamics from inverse aircraft modeling  

E-Print Network [OSTI]

This thesis presents a method of construe' ting a nonlinear dynamics model of a theoretical aircraft from the nonlinear batch simulation of an existing aircrew This method provides control law designers with a method of fabricating nonlinear models...

Ziegler, Gregory E

1999-01-01T23:59:59.000Z

26

A Dynamic Model of Thundercloud Electric Fields  

Science Journals Connector (OSTI)

A dynamic interactive computer model of the electrical behavior of a thundercloud surrounded by the distributed atmosphere, earth, ionosphere circuit is described. The electrification mechanisms in the model are represented by current or voltage ...

John S. Nisbet

1983-12-01T23:59:59.000Z

27

A Robust Model Control for Dynamic Systems  

Science Journals Connector (OSTI)

Analytical methods of polynomial algebra, heuristic techniques, and digital modeling are used to study the robustness domain of linear dynamic systems with model “input–output” controllers as a function of the mutual locations of zeros ...

S. V. Tararykin; V. V. Tyutikov

2002-05-01T23:59:59.000Z

28

Dynamic LES Modeling of a Diurnal Cycle  

Science Journals Connector (OSTI)

The diurnally varying atmospheric boundary layer observed during the Wangara (Australia) case study is simulated using the recently proposed locally averaged scale-dependent dynamic subgrid-scale (SGS) model. This tuning-free SGS model enables ...

Sukanta Basu; Jean-François Vinuesa; Andrew Swift

2008-04-01T23:59:59.000Z

29

Model Validation with Hybrid Dynamic Simulation  

SciTech Connect (OSTI)

Abstract—Model validation has been one of the central topics in power engineering studies for years. As model validation aims at obtaining reasonable models to represent actual behavior of power system components, it has been essential to validate models against actual measurements or known benchmark behavior. System-wide model simulation results can be compared with actual recordings. However, it is difficult to construct a simulation case for a large power system such as the WECC system and to narrow down to problematic models in a large system. Hybrid dynamic simulation with its capability of injecting external signals into dynamic simulation enables rigorous comparison of measurements and simulation in a small subsystem of interest. This paper presents such a model validation methodology with hybrid dynamic simulation. Two application examples on generator and load model validation are presented to show the validity of this model validation methodology. This methodology is further extended for automatic model validation and dichotomous subsystem model validation.

Huang, Zhenyu; Kosterev, Dmitry; Guttromson, Ross T.; Nguyen, Tony B.

2006-06-18T23:59:59.000Z

30

Calcium Dynamics in Large Neuronal Models  

E-Print Network [OSTI]

Chapter 6 Calcium Dynamics in Large Neuronal Models ERIK DE SCHUTTER and PAUL SMOLEN 6.1 Introduction Calcium is an important intracellular signaling molecule with rapid e ect on the kinetics of many active membrane model that includes Ca2+ dynamics, one is faced with a feedback loop: the Ca2+-activated

De Schutter, Erik

31

Adjoint modeling for atmospheric pollution process sensitivity at regional scale  

E-Print Network [OSTI]

Adjoint modeling for atmospheric pollution process sensitivity at regional scale Laurent Menut; 0345 Atmospheric Composition and Structure: Pollution--urban and regional (0305); 3210 Mathematical: atmospheric pollution, tropospheric ozone, urban pollution peaks, adjoint modeling, sensitivity Citation

Menut, Laurent

32

The MAGS Regional Climate Modeling System: CRCM-MAGS  

Science Journals Connector (OSTI)

The Mackenzie GEWEX Study (MAGS) regional climate modeling system (denoted CRCM-MAGS) is a developmental version of the Canadian Regional Climate Model (CRCM) tailored for use over North America. It is compose...

Murray MacKay; Paul Bartlett; Ed Chan…

2008-01-01T23:59:59.000Z

33

Dynamical investigation and parameter stability region analysis of a flywheel energy storage system in charging mode  

Science Journals Connector (OSTI)

In this paper, the dynamic behavior analysis of the electromechanical coupling characteristics of a flywheel energy storage system (FESS) with a permanent magnet (PM) brushless direct-current (DC) motor (BLDCM) is studied. The Hopf bifurcation theory and nonlinear methods are used to investigate the generation process and mechanism of the coupled dynamic behavior for the average current controlled FESS in the charging mode. First, the universal nonlinear dynamic model of the FESS based on the BLDCM is derived. Then, for a 0.01 kWh/1.6 kW FESS platform in the Key Laboratory of the Smart Grid at Tianjin University, the phase trajectory of the FESS from a stable state towards chaos is presented using numerical and stroboscopic methods, and all dynamic behaviors of the system in this process are captured. The characteristics of the low-frequency oscillation and the mechanism of the Hopf bifurcation are investigated based on the Routh stability criterion and nonlinear dynamic theory. It is shown that the Hopf bifurcation is directly due to the loss of control over the inductor current, which is caused by the system control parameters exceeding certain ranges. This coupling nonlinear process of the FESS affects the stability of the motor running and the efficiency of energy transfer. In this paper, we investigate into the effects of control parameter change on the stability and the stability regions of these parameters based on the averaged-model approach. Furthermore, the effect of the quantization error in the digital control system is considered to modify the stability regions of the control parameters. Finally, these theoretical results are verified through platform experiments.

Zhang Wei-Ya (???); Li Yong-Li (???); Chang Xiao-Yong (???); Wang Nan (? ?)

2013-01-01T23:59:59.000Z

34

Very Large System Dynamics Models - Lessons Learned  

SciTech Connect (OSTI)

This paper provides lessons learned from developing several large system dynamics (SD) models. System dynamics modeling practice emphasize the need to keep models small so that they are manageable and understandable. This practice is generally reasonable and prudent; however, there are times that large SD models are necessary. This paper outlines two large SD projects that were done at two Department of Energy National Laboratories, the Idaho National Laboratory and Sandia National Laboratories. This paper summarizes the models and then discusses some of the valuable lessons learned during these two modeling efforts.

Jacob J. Jacobson; Leonard Malczynski

2008-10-01T23:59:59.000Z

35

Diamond Lattice Model of Semicrystalline Polyethylene in the Amorphous Region  

E-Print Network [OSTI]

Diamond Lattice Model of Semicrystalline Polyethylene in the Amorphous Region Zhong­Hui Duan Abstract The statistics of polyethylene chains in the amorphous region between two crystallites have been as models of the chain molecules in the amorphous region of semicrystalline polyethylene, both

Aluffi, Paolo

36

Simple Dynamic Gasifier Model That Runs in Aspen Dynamics  

SciTech Connect (OSTI)

Gasification (or partial oxidation) is a vital component of 'clean coal' technology. Sulfur and nitrogen emissions can be reduced, overall energy efficiency is increased, and carbon dioxide recovery and sequestration are facilitated. Gasification units in an electric power generation plant produce a fuel for driving combustion turbines. Gasification units in a chemical plant generate gas, which can be used to produce a wide spectrum of chemical products. Future plants are predicted to be hybrid power/chemical plants with gasification as the key unit operation. The widely used process simulator Aspen Plus provides a library of models that can be used to develop an overall gasifier model that handles solids. So steady-state design and optimization studies of processes with gasifiers can be undertaken. This paper presents a simple approximate method for achieving the objective of having a gasifier model that can be exported into Aspen Dynamics. The basic idea is to use a high molecular weight hydrocarbon that is present in the Aspen library as a pseudofuel. This component should have the same 1:1 hydrogen-to-carbon ratio that is found in coal and biomass. For many plantwide dynamic studies, a rigorous high-fidelity dynamic model of the gasifier is not needed because its dynamics are very fast and the gasifier gas volume is a relatively small fraction of the total volume of the entire plant. The proposed approximate model captures the essential macroscale thermal, flow, composition, and pressure dynamics. This paper does not attempt to optimize the design or control of gasifiers but merely presents an idea of how to dynamically simulate coal gasification in an approximate way.

Robinson, P.J.; Luyben, W.L. [Lehigh University, Bethlehem, PA (United States). Dept. of Chemical Engineering

2008-10-15T23:59:59.000Z

37

A quantum cascade laser in a transverse magnetic field. A model of the open triple-barrier active region  

Science Journals Connector (OSTI)

A theory of spectral parameters and active dynamic conductivity of the quantum cascade laser is proposed in the model of a triple-barrier active region of an individual cascade in a transverse magnetic field. In ...

N. V. Tkach; I. V. Boyko; Ju. A. Seti; G. G. Zegrya

2013-06-01T23:59:59.000Z

38

Model Validation with Hybrid Dynamic Simulation  

SciTech Connect (OSTI)

Abstract—Model validation has been one of the central topics in power engineering studies for years. As model validation aims at obtaining reasonable models to represent actual behavior of power system components, it has been essential to validate models against actual measurements or known benchmark behavior. System-wide model simulation results can be compared with actual recordings. However, it is difficult to construct a simulation case for a large power system such as the WECC system and to narrow down to problematic models in a large system. Hybrid dynamic simulation with its capability of injecting external signals into dynamic simulation enables rigorous comparison of measurements and simulation in a small subsystem of interest. This paper presents such a model validation methodology with hybrid dynamic simulation. Two application examples on generator and load model validation are presented to show the validity of this model validation methodology. This methodology is further extended for automatic model validation and dichotomous subsystem model validation. A few methods to define model quality indices have been proposed to quantify model error for model validation criteria development.

Huang, Zhenyu; Kosterev, Dmitry; Guttromson, Ross T.; Nguyen, Tony B.

2006-06-22T23:59:59.000Z

39

NREL: Regional Energy Deployment System (ReEDS) Model - Publications  

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

Regional Energy Deployment System (ReEDS) Model Energy Analysis ReEDS Regional Energy Deployment System Model Regional Energy Deployment System (ReEDS) Model Energy Analysis ReEDS Regional Energy Deployment System Model Search More Search Options Site Map Printable Version Publications The following are publications - including technical reports, journal articles, conference papers, and posters - focusing on the Wind Deployment System (WinDS) and Regional Energy Deployment System (ReEDS) models. Technical Reports Eurek, K.; Denholm, P.; Margolis, R.; Mowers, M. (2013). Sensitivity of Utility-Scale Solar Deployment Projections in the SunShot Vision Study to Market and Performance Assumptions. 55 pp.; NREL Report No. TP-6A20-55836. Martinez, A.; Eurek, K.; Mai, T.; Perry, A. (2013). Integrated Canada-U.S. Power Sector Modeling with the Regional Energy Deployment System (ReEDS).

40

NETL: Predictive Modeling and Evaluation - CMU Regional Modeling Study  

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

Regional Source-Receptor Modeling Study Regional Source-Receptor Modeling Study The Pittsburgh Air Quality Study (PAQS) [PDF-744KB] is comprised of three inter-related components: 1) ambient PM measurements, 2) source characterization, and 3) deterministic and statistical air quality modeling. This effort will permit clarification of the contribution of coal-fired power plants to fine ambient PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 µm). The resources from the Department of Energy (DOE) will be leveraged with resources from the Environmental Protection Agency (EPA) and other organizations. Clarkson University (Hopke group) will apply advanced receptor models to identify the nature, location and contribution of the sources of particulate matter observed by the measurements made as part of the PAQS. Several forms of factor analysis including Positive Matrix Factorization (PMF) and UNMIX will be applied in order to identify the composition and contributions of the sources. Potential Source Contribution Function analysis as well as Residence Time Weighted Concentration analysis will be applied to the determination of the locations of the likely major contributing sources. The aforementioned factor analysis methods will also be applied to the spatially distributed data both on a single species and multiple species basis and to compare these results with those obtained utilizing the back-trajectory-based methods. The availability of highly time resolved data should permit greater source resolution and will be examined to determine how much increased source specificity can be obtained from the increased time resolution in the data. Assistance will be provided with the multivariate calibration that will permit the use of single-particle mass spectrometry data to estimate ambient concentrations of particulate species. These analyses should provide a better understanding of the source/receptor relationships that lead to the observed particle concentrations in the Pittsburgh area.

Note: This page contains sample records for the topic "regional dynamics model" 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

A stochastic evolutionary model for survival dynamics  

E-Print Network [OSTI]

The recent interest in human dynamics has led researchers to investigate the stochastic processes that explain human behaviour in different contexts. Here we propose a generative model to capture the essential dynamics of survival analysis, traditionally employed in clinical trials and reliability analysis in engineering. In our model, the only implicit assumption made is that the longer an actor has been in the system, the more likely it is to have failed. We derive a power-law distribution for the process and provide preliminary empirical evidence for the validity of the model from two well-known survival analysis data sets.

Fenner, Trevor; Loizou, George

2014-01-01T23:59:59.000Z

42

Modeling Internet Topology Dynamics Hamed Haddadi  

E-Print Network [OSTI]

graphs. Generation of the topology of the Internet calls for a model that achieves a good balance betweenModeling Internet Topology Dynamics Hamed Haddadi University College London Steve Uhlig Delft and inference, there still exists ambiguity about the real nature of the Internet AS and router level topol- ogy

Haddadi, Hamed

43

Dynamic modeling of IGCC power plants  

Science Journals Connector (OSTI)

Integrated Gasification Combined Cycle (IGCC) power plants are an effective option to reduce emissions and implement carbon-dioxide sequestration. The combination of a very complex fuel-processing plant and a combined cycle power station leads to challenging problems as far as dynamic operation is concerned. Dynamic performance is extremely relevant because recent developments in the electricity market push toward an ever more flexible and varying operation of power plants. A dynamic model of the entire system and models of its sub-systems are indispensable tools in order to perform computer simulations aimed at process and control design. This paper presents the development of the lumped-parameters dynamic model of an entrained-flow gasifier, with special emphasis on the modeling approach. The model is implemented into software by means of the Modelica language and validated by comparison with one set of data related to the steady operation of the gasifier of the Buggenum power station in the Netherlands. Furthermore, in order to demonstrate the potential of the proposed modeling approach and the use of simulation for control design purposes, a complete model of an exemplary IGCC power plant, including its control system, has been developed, by re-using existing models of combined cycle plant components; the results of a load dispatch ramp simulation are presented and shortly discussed.

F. Casella; P. Colonna

2012-01-01T23:59:59.000Z

44

Dynamics of H II regions around exiled O stars  

Science Journals Connector (OSTI)

......the stellar space velocity increases. Raga...lower density ISM at velocities v -12s1 (Franco...recombination-line emission-maps of Hii regions are...Hii regions. The velocity range between transonic...that from stellar winds, at least for moderate-velocity...constraining the mass-loss rates of massive......

Jonathan Mackey; Norbert Langer; Vasilii V. Gvaramadze

2013-01-01T23:59:59.000Z

45

A multi-agent model of several economic regions  

Science Journals Connector (OSTI)

This paper presents Lagom regiO: a multi-agent model of several growing economic areas in interaction. The model is part of the Lagom model family: economic multi-agent models developed to make steps toward understanding equilibrium selection and identifying ... Keywords: Economic regions, Emissions, Growing economy, Multi-agent model

Sarah Wolf; Steffen FüRst; Antoine Mandel; Wiebke Lass; Daniel Lincke; Federico Pablo-Martí; Carlo Jaeger

2013-06-01T23:59:59.000Z

46

The WAMME regional model intercomparison study  

E-Print Network [OSTI]

has produced a multi-model climatology of land surface ?uxesThe Global Precipitation Climatology Project (GPCP) combined

2010-01-01T23:59:59.000Z

47

Phenomenological models of socioeconomic network dynamics  

Science Journals Connector (OSTI)

We study a general set of models of social network evolution and dynamics. The models consist of both a dynamics on the network and evolution of the network. Links are formed preferentially between “similar” nodes, where the similarity is defined by the particular process taking place on the network. The interplay between the two processes produces phase transitions and hysteresis, as seen using numerical simulations for three specific processes. We obtain analytic results using mean-field approximations, and for a particular case we derive an exact solution for the network. In common with real-world social networks, we find coexistence of high and low connectivity phases and history dependence.

George C. M. A. Ehrhardt; Matteo Marsili; Fernando Vega-Redondo

2006-09-13T23:59:59.000Z

48

Modeling emotional dynamics : currency versus field.  

SciTech Connect (OSTI)

Randall Collins has introduced a simplified model of emotional dynamics in which emotional energy, heightened and focused by interaction rituals, serves as a common denominator for social exchange: a generic form of currency, except that it is active in a far broader range of social transactions. While the scope of this theory is attractive, the specifics of the model remain unconvincing. After a critical assessment of the currency theory of emotion, a field model of emotion is introduced that adds expressiveness by locating emotional valence within its cognitive context, thereby creating an integrated orientation field. The result is a model which claims less in the way of motivational specificity, but is more satisfactory in modeling the dynamic interaction between cognitive and emotional orientations at both individual and social levels.

Sallach, D .L.; Decision and Information Sciences; Univ. of Chicago

2008-08-01T23:59:59.000Z

49

Modeling of Reactor Kinetics and Dynamics  

SciTech Connect (OSTI)

In order to model a full fuel cycle in a nuclear reactor, it is necessary to simulate the short time-scale kinetic behavior of the reactor as well as the long time-scale dynamics that occur with fuel burnup. The former is modeled using the point kinetics equations, while the latter is modeled by coupling fuel burnup equations with the kinetics equations. When the equations are solved simultaneously with a nonlinear equation solver, the end result is a code with the unique capability of modeling transients at any time during a fuel cycle.

Matthew Johnson; Scott Lucas; Pavel Tsvetkov

2010-09-01T23:59:59.000Z

50

Modeling joint friction in structural dynamics.  

SciTech Connect (OSTI)

The presence of mechanical joints--typified by the lap joint--in otherwise linear structures has been accommodated in structural dynamics via ad hoc methods for a century. The methods range from tuning linear models to approximate non-linear behavior in restricted load ranges to various methods which introduce joint dissipation in a post-processing stage. Other methods, employing constitutive models for the joints are being developed and their routine use is on the horizon.

Segalman, Daniel Joseph

2005-05-01T23:59:59.000Z

51

The WAMME regional model intercomparison study  

E-Print Network [OSTI]

Á D. P. Rowell Met Of?ce Hadley Centre, Exeter, UK E. K.parametrizations in the Hadley Centre climate model: HadAM3.2008). The UK Met Of?ce Hadley Centre RCM is known as Had-

2010-01-01T23:59:59.000Z

52

Dynamic model of hysteretic elastic systems  

Science Journals Connector (OSTI)

A model for the dynamical behavior of a hysteretic elastic system is introduced and studied numerically. This model consists of a chain of hysteretic elastic elements. Each elastic element is a spring with properties that depend on an Ising-like state variable having Brownian dynamics in an energy landscape with structure that is sensitive to the forces which the elastic element must support. A single elastic element is studied carefully, numerically in order to establish its basic behavior. A one dimensional chain of N=500 elastic elements, driven like a resonant bar, is studied numerically. The data from this study are analyzed by the methods employed in analyzing similar experimental data. The behavior of the numerical model compares well with the behavior of physical realizations of hysteretic elastic systems.

Barbara Capogrosso-Sansone and R. A. Guyer

2002-12-05T23:59:59.000Z

53

A Framework for Modeling Uncertainty in Regional Climate Change  

E-Print Network [OSTI]

In this study, we present a new modeling framework and a large ensemble of climate projections to investigate the uncertainty in regional climate change over the US associated with four dimensions of uncertainty. The sources ...

Monier, Erwan

54

The dynamic radiation environment assimilation model (DREAM)  

SciTech Connect (OSTI)

The Dynamic Radiation Environment Assimilation Model (DREAM) is a 3-year effort sponsored by the US Department of Energy to provide global, retrospective, or real-time specification of the natural and potential nuclear radiation environments. The DREAM model uses Kalman filtering techniques that combine the strengths of new physical models of the radiation belts with electron observations from long-term satellite systems such as GPS and geosynchronous systems. DREAM includes a physics model for the production and long-term evolution of artificial radiation belts from high altitude nuclear explosions. DREAM has been validated against satellites in arbitrary orbits and consistently produces more accurate results than existing models. Tools for user-specific applications and graphical displays are in beta testing and a real-time version of DREAM has been in continuous operation since November 2009.

Reeves, Geoffrey D [Los Alamos National Laboratory; Koller, Josef [Los Alamos National Laboratory; Tokar, Robert L [Los Alamos National Laboratory; Chen, Yue [Los Alamos National Laboratory; Henderson, Michael G [Los Alamos National Laboratory; Friedel, Reiner H [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

55

Modeling-Computer Simulations At Central Nevada Seismic Zone Region  

Open Energy Info (EERE)

Central Nevada Seismic Zone Region Central Nevada Seismic Zone Region (Blackwell, Et Al., 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Central Nevada Seismic Zone Region (Blackwell, Et Al., 2003) Exploration Activity Details Location Central Nevada Seismic Zone Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes Developed natural state mass and energy transport fluid flow models of generic Basin and Range systems based on Dixie Valley data that help to understand the nature of large scale constraints on the location and characteristics of the geothermal systems References D. D. Blackwell, K. W. Wisian, M. C. Richards, Mark Leidig, Richard Smith, Jason McKenna (2003) Geothermal Resource Analysis And Structure Of

56

Regional knowledge dynamics in the biotechnology industry: a conceptual framework for micro-level analysis  

Science Journals Connector (OSTI)

In this paper, we propose a firm-based micro-level framework for the analysis of regional knowledge dynamics. This approach contrasts with most of the established literature on regional clusters, learning regions, industrial districts or Regional Innovation Systems (RISs), which focus mainly on the meso-level of industrial organisation. Contrary to those concepts we are using a biographical method that maps the firm's innovation processes and practices and further on evaluates how those processes are interrelated with intra-organisational change and knowledge flows across different territorial levels.

Robert Kaiser; Michael Liecke

2009-01-01T23:59:59.000Z

57

DYNAMICAL MODELING OF GALAXY MERGERS USING IDENTIKIT  

SciTech Connect (OSTI)

We present dynamical models of four interacting systems: NGC 5257/8, The Mice, the Antennae, and NGC 2623. The parameter space of the encounters are constrained using the Identikit model-matching and visualization tool. Identikit utilizes hybrid N-body and test particle simulations to enable rapid exploration of the parameter space of galaxy mergers. The Identikit-derived matches of these systems are reproduced with self-consistent collisionless simulations which show very similar results. The models generally reproduce the observed morphology and H I kinematics of the tidal tails in these systems with reasonable properties inferred for the progenitor galaxies. The models presented here are the first to appear in the literature for NGC 5257/8 and NGC 2623, and The Mice and the Antennae are compared with previously published models. Based on the assumed mass model and our derived initial conditions, the models indicate that the four systems are currently being viewed 175-260 Myr after first passage and cover a wide range of merger stages. In some instances there are mismatches between the models and the data (e.g., in the length of a tail); these are likely due to our adoption of a single mass model for all galaxies. Despite the use of a single mass model, these results demonstrate the utility of Identikit in constraining the parameter space for galaxy mergers when applied to real data.

Privon, G. C.; Evans, A. S. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States); Barnes, J. E. [Institute for Astronomy, University of Hawaii, at Manoa, Honolulu, HI (United States); Hibbard, J. E. [National Radio Astronomy Observatory, Charlottesville, VA 22904 (United States); Yun, M. S. [Astronomy Department, University of Massachusetts, Amherst, MA 01003 (United States); Mazzarella, J. M. [NASA Infrared Processing and Analysis Center, California Institute of Technology, Pasadena, CA 91125 (United States); Armus, L.; Surace, J., E-mail: gcp8y@virginia.edu [Spitzer Science Center, California Institute of Technology, Pasadena, CA 91125 (United States)

2013-07-10T23:59:59.000Z

58

Computational battery dynamics (CBD)--electrochemical/thermal coupled modeling and multi-scale modeling  

E-Print Network [OSTI]

Computational battery dynamics (CBD)--electrochemical/thermal coupled modeling and multi the development of first-principles based mathematical models for batteries developed on a framework parallel to computation fluid dynamics (CFD), herein termed computational battery dynamics (CBD). This general

59

A Game-Theoretical Dynamic Model for Electricity Markets  

E-Print Network [OSTI]

Oct 6, 2010 ... Abstract: We present a game-theoretical dynamic model for competitive electricity markets.We demonstrate that the model can be used to ...

Aswin Kannan

2010-10-06T23:59:59.000Z

60

NON-LINEAR MODELING OF THE RHIC INTERACTION REGIONS.  

SciTech Connect (OSTI)

For RHIC's collision lattices the dominant sources of transverse non-linearities are located in the interaction regions. The field quality is available for most of the magnets in the interaction regions from the magnetic measurements, or from extrapolations of these measurements. We discuss the implementation of these measurements in the MADX models of the Blue and the Yellow rings and their impact on beam stability.

TOMAS,R.FISCHER,W.JAIN,A.LUO,Y.PILAT,F.

2004-07-05T23:59:59.000Z

Note: This page contains sample records for the topic "regional dynamics model" 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

Protecting the African elephant: A dynamic bioeconomic model of ivory trade  

E-Print Network [OSTI]

Protecting the African elephant: A dynamic bioeconomic model of ivory trade G. Cornelis van Kooten Accepted 25 May 2008 Available online 7 July 2008 Keywords: Economics Elephant conservation Ivory trade ban on the protection of the African elephant (Laxadonta africana). The model consists of four ivory exporting regions

62

Design of a next-generation regional weather research and forecast model.  

SciTech Connect (OSTI)

The Weather Research and Forecast (WRF) model is a new model development effort undertaken jointly by the National Center for Atmospheric Research (NCAR), the National Oceanic and Atmospheric Administration (NOAA), and a number of collaborating institutions and university scientists. The model is intended for use by operational NWP and university research communities, providing a common framework for idealized dynamical studies, fill physics numerical weather prediction, air-quality simulation, and regional climate. It will eventually supersede large, well-established but aging regional models now maintained by the participating institutions. The WRF effort includes re-engineering the underlying software architecture to produce a modular, flexible code designed from the outset to provide portable performance across diverse computing architectures. This paper outlines key elements of the WRF software design.

Michalakes, J.

1999-01-13T23:59:59.000Z

63

MODELING PLANT COMPETITION WITH THE GAPS OBJECT-ORIENTED DYNAMIC SIMULATION MODEL  

E-Print Network [OSTI]

MODELING PLANT COMPETITION WITH THE GAPS OBJECT-ORIENTED DYNAMIC SIMULATION MODEL David G. Rossiter of Agronomy, Inc. #12;MODELING PLANT COMPETITION WITH THE GAPS OBJECT-ORIENTED DYNAMIC SIMULATION MODEL Abstract Modeling inter-species competition is a natural application for dynamic simulation models

Rossiter, D G "David"

64

A Mechanical Fluid-Dynamical Model For Ground Movements At Campi Flegrei  

Open Energy Info (EERE)

Mechanical Fluid-Dynamical Model For Ground Movements At Campi Flegrei Mechanical Fluid-Dynamical Model For Ground Movements At Campi Flegrei Caldera Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Mechanical Fluid-Dynamical Model For Ground Movements At Campi Flegrei Caldera Details Activities (0) Areas (0) Regions (0) Abstract: We present here a consistent model, which explains the mechanisms of unrest phenomena at Campi Flegrei (Italy), both at short-term (years) and at secular scales. The model consists basically of two effects: the first one is related to the elastic response of the shallow crust to increasing pressure within a shallow magma chamber; the second involves the fluid-dynamics of shallow aquifers in response to increasing pressure and/or temperature at depth. The most important roles in the proposed model

65

Regional climate model data used within the SWURVE project 2: addressing uncertainty in regional climate model data Hydrol. Earth Syst. Sci., 11(1), 10851096, 2007  

E-Print Network [OSTI]

Regional climate model data used within the SWURVE project 2: addressing uncertainty in regional within the SWURVE project 2: addressing uncertainty in regional climate model data for five European case regions (CSRs) of the EC-funded project SWURVE, estimates of uncertainty in climate model data need

Boyer, Edmond

66

A Dynamical IS-LM Model Allen Tang  

E-Print Network [OSTI]

A Dynamical IS-LM Model Allen Tang The University of North Carolina the specifications of a discrete dynamical IS-LM model and discuss how this model can of monetary policy, to an economy. The standard static IS-LM model arises

Marzuola, Jeremy

67

A SPATIAL WEB GRAPH MODEL WITH LOCAL INFLUENCE REGIONS  

E-Print Network [OSTI]

A SPATIAL WEB GRAPH MODEL WITH LOCAL INFLUENCE REGIONS W. AIELLO, A. BONATO, C. COOPER, J. JANSSEN- served in real-world networks such as the web graph. On the other hand, experimental and heuristic network can be recognized as densely linked subgraphs, or that web pages with many common neigh- bours

Pralat, Pawel

68

THE DEVELOPMENT MODEL ELECTRONIC COMMERCE OF REGIONAL AGRICULTURE  

E-Print Network [OSTI]

THE DEVELOPMENT MODEL ELECTRONIC COMMERCE OF REGIONAL AGRICULTURE Jun Kang* , Lecai Cai, Hongchan, Fax: +86-813-5505966, Email: kj_sky@126.com Abstract: With the developing of the agricultural information, it is inevitable trend of the development of agricultural electronic commercial affairs

Boyer, Edmond

69

A Numerical Model For The Dynamics Of Pyroclastic Flows At Galeras Volcano,  

Open Energy Info (EERE)

For The Dynamics Of Pyroclastic Flows At Galeras Volcano, For The Dynamics Of Pyroclastic Flows At Galeras Volcano, Colombia Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: A Numerical Model For The Dynamics Of Pyroclastic Flows At Galeras Volcano, Colombia Details Activities (0) Areas (0) Regions (0) Abstract: This paper presents a two-dimensional model for dilute pyroclastic flow dynamics that uses the compressible Navier-Stokes equation coupled with the Diffusion-Convection equation to take into account sedimentation. The model is applied to one of the slopes of Galeras Volcano to show: (1) the temperature evolution with the time; (2) dynamic pressure change; and (3) particle concentration along the computer domain from the eruption to the impact with a topographic barrier located more than 16 km

70

Censored Glauber Dynamics for the Mean Field Ising Model  

E-Print Network [OSTI]

dynamics for the Mean-?eld Ising Model: cut-off, criticaldynamics for the mean-?eld Ising model. Commun. Math. Phys.to equilibrium of stochastic Ising models in the Dobrushin

Ding, Jian; Lubetzky, Eyal; Peres, Yuval

2009-01-01T23:59:59.000Z

71

Modeling of air currents in the Gulf Region  

SciTech Connect (OSTI)

The Atmospheric Release Advisory Capability modeled the wind flow in the Gulf Region in order to make projections of the Kuwait oil fires pollution dispersion. Extensive meteorological models incorporating explicit terrain influences to the flow fields were routinely employed through a six month international assessment support effort organized by the World Meteorological Organization and US scientific research agencies. Results show generally close agreement with visible imagery of the smoke plumes as detected by meteorological satellites. However, there are some examples of significant disagreement or failure of the meteorological models. These failures are most likely directly linked to missing or unavailable weather observations.

Sullivan, T.J.; Ellis, J.S.; Foster, C.S.; Foster, K.T.; Baskett, R.L.; Nasstrom, J.S.; Schalk, W.W.

1992-04-14T23:59:59.000Z

72

Open problem: Dynamic Relational Models for Improved Hazardous Weather Prediction  

E-Print Network [OSTI]

. Current weather radar detection and prediction sys- tems primarily rely on numerical models. We proposeOpen problem: Dynamic Relational Models for Improved Hazardous Weather Prediction Amy McGovern1, #12;Dynamic Relational Models for Improved Hazardous Weather Prediction Radar velocity Radar

McGovern, Amy

73

HOMOGENEOUS MODELS IN GENERAL RELATIVITY AND GAS DYNAMICS  

E-Print Network [OSTI]

HOMOGENEOUS MODELS IN GENERAL RELATIVITY AND GAS DYNAMICS O. I. BOGOYAVLENSKII AND S. P. NOVIKOV analytically) in general relativity and gas dynamics. The investigation of these models is carried out begins with a short survey of results on non-trivial models (that is, those that are not integrable

Novikov, Sergei Petrovich

74

Regional forecasting with global atmospheric models; Final report  

SciTech Connect (OSTI)

The purpose of the project was to conduct model simulations for past and future climate change with respect to the proposed Yucca Mtn. repository. The authors report on three main topics, one of which is boundary conditions for paleo-hindcast studies. These conditions are necessary for the conduction of three to four model simulations. The boundary conditions have been prepared for future runs. The second topic is (a) comparing the atmospheric general circulation model (GCM) with observations and other GCMs; and (b) development of a better precipitation data base for the Yucca Mtn. region for comparisons with models. These tasks have been completed. The third topic is preliminary assessments of future climate change. Energy balance model (EBM) simulations suggest that the greenhouse effect will likely dominate climate change at Yucca Mtn. for the next 10,000 years. The EBM study should improve rational choice of GCM CO{sub 2} scenarios for future climate change.

Crowley, T.J.; Smith, N.R. [Applied Research Corp., College Station, TX (United States)

1994-05-01T23:59:59.000Z

75

Regional-Scale Climate Change: Observations and Model Simulations  

SciTech Connect (OSTI)

This collaborative proposal addressed key issues in understanding the Earthâ??s climate system, as highlighted by the U.S. Climate Science Program. The research focused on documenting past climatic changes and on assessing future climatic changes based on suites of global and regional climate models. Geographically, our emphasis was on the mountainous regions of the world, with a particular focus on the Neotropics of Central America and the Hawaiian Islands. Mountain regions are zones where large variations in ecosystems occur due to the strong climate zonation forced by the topography. These areas are particularly susceptible to changes in critical ecological thresholds, and we conducted studies of changes in phonological indicators based on various climatic thresholds.

Raymond S. Bradley; Henry F. Diaz

2010-12-14T23:59:59.000Z

76

Dispersive processes in models of regional radionuclide migration. Technical memorandum  

SciTech Connect (OSTI)

Three broad areas of concern in the development of aquifer scale transport models will be local scale diffusion and dispersion processes, regional scale dispersion processes, and numerical problems associated with the advection-dispersion equation. Local scale dispersion processes are fairly well understood and accessible to observation. These processes will generally be dominated in large scale systems by regional processes, or macro-dispersion. Macro-dispersion is primarily the result of large scale heterogeneities in aquifer properties. In addition, the effects of many modeling approximations are often included in the process. Because difficulties arise in parameterization of this large scale phenomenon, parameterization should be based on field measurements made at the same scale as the transport process of interest or else partially circumvented through the application of a probabilistic advection model. Other problems associated with numerical transport models include difficulties with conservation of mass, stability, numerical dissipation, overshoot, flexibility, and efficiency. We recommend the random-walk model formulation for Lawrence Livermore Laboratory's purposes as the most flexible, accurate and relatively efficient modeling approach that overcomes these difficulties.

Evenson, D.E.; Dettinger, M.D.

1980-05-01T23:59:59.000Z

77

Smoothing in dynamic generalized linear models by Gibbs sampling  

Science Journals Connector (OSTI)

Optimal filtering and smoothing in non-Gaussian dynamic models based on ... approach for obtaining posterior mean smoothers in the exponential family framework. Implementation and performance are investigated...

Ludwig Fahrmeir; Wolfgang Hennevogl…

1992-01-01T23:59:59.000Z

78

Asperity Model of an Earthquake - Dynamic Problem  

SciTech Connect (OSTI)

We develop an earthquake asperity model that explains previously determined empirical scaling relationships for repeating earthquakes along the San Andreas fault in central California. The model assumes that motion on the fault is resisted primarily by a patch of small strong asperities that interact with each other to increase the amount of displacement needed to cause failure. This asperity patch is surrounded by a much weaker fault that continually creeps in response to tectonic stress. Extending outward from the asperity patch into the creeping part of the fault is a shadow region where a displacement deficit exists. Starting with these basic concepts, together with the analytical solution for the exterior crack problem, the consideration of incremental changes in the size of the asperity patch leads to differential equations that can be solved to yield a complete static model of an earthquake. Equations for scalar seismic moment, the radius of the asperity patch, and the radius of the displacement shadow are all specified as functions of the displacement deficit that has accumulated on the asperity patch. The model predicts that the repeat time for earthquakes should be proportional to the scalar moment to the 1/6 power, which is in agreement with empirical results for repeating earthquakes. The model has two free parameters, a critical slip distance dc and a scaled radius of a single asperity. Numerical values of 0.20 and 0.17 cm, respectively, for these two parameters will reproduce the empirical results, but this choice is not unique. Assuming that the asperity patches are distributed on the fault surface in a random fractal manner leads to a frequency size distribution of earthquakes that agrees with the Gutenberg Richter formula and a simple relationship between the b-value and the fractal dimension. We also show that the basic features of the theoretical model can be simulated with numerical calculations employing the boundary integral method.

Johnson, Lane R.; Nadeau, Robert M.

2003-05-02T23:59:59.000Z

79

Modeling Dynamics and Exploring Control of a Single-Wheeled Dynamically Stable Mobile  

E-Print Network [OSTI]

Modeling Dynamics and Exploring Control of a Single-Wheeled Dynamically Stable Mobile Robot. It actively balances and moves on a single wheel using closed loop feedback, making it dynamically stable it a good candidate for operating in human environments. Balancing on a ball allows Ballbot to be omni

80

A dynamic model for the Lagrangian stochastic dispersion coefficient  

SciTech Connect (OSTI)

A stochastic sub-grid model is often used to accurately represent particle dispersion in turbulent flows using large eddy simulations. Models of this type have a free parameter, the dispersion coefficient, which is not universal and is strongly grid-dependent. In the present paper, a dynamic model for the evaluation of the coefficient is proposed and validated in decaying homogeneous isotropic turbulence. The grid dependence of the static coefficient is investigated in a turbulent mixing layer and compared to the dynamic model. The dynamic model accurately predicts dispersion statistics and resolves the grid-dependence. Dispersion statistics of the dynamically calculated constant are more accurate than any static coefficient choice for a number of grid spacings. Furthermore, the dynamic model produces less numerical artefacts than a static model and exhibits smaller sensitivity in the results predicted for different particle relaxation times.

Pesmazoglou, I.; Navarro-Martinez, S., E-mail: s.navarro@imperial.ac.uk [Department of Mechanical Engineering, Imperial College, London SW7 2AZ (United Kingdom); Kempf, A. M. [Chair of Fluid Dynamics, Institute for Combustion and Gasdynamics and Center for Computational Sciences and Simulation, Universität Duisburg-Essen, Duisburg, 47048 (Germany)] [Chair of Fluid Dynamics, Institute for Combustion and Gasdynamics and Center for Computational Sciences and Simulation, Universität Duisburg-Essen, Duisburg, 47048 (Germany)

2013-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "regional dynamics model" 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

Event-Based Approach to Modelling Dynamic Architecture  

E-Print Network [OSTI]

Event-Based Approach to Modelling Dynamic Architecture: Application to Mobile Ad-Hoc Network.Attiogbe@univ-nantes.fr Abstract. We describe an event-based approach to specifiy systems with dynamically evolving architecture tools. Keywords: Specification, Verification, Dynamic Architecture, Event B. 1 Introduction Distributed

Paris-Sud XI, Université de

82

Dynamic Modeling of a Two Wheeled Vehicle : Jourdain Formalism  

E-Print Network [OSTI]

This paper presents a motorcycle direct dynamic formulation by the Jourdain's principle approach on the motorcycle's handlebar. Simulation results reveal some dynamics features like load transfer and counter-steering phenomena. keywords Motorcycle modeling, motorcycle control, Jourdain's dynamics principle. 1 Introduction

Paris-Sud XI, Université de

83

California Wintertime Precipitation in Regional and Global Climate Models  

SciTech Connect (OSTI)

In this paper, wintertime precipitation from a variety of observational datasets, regional climate models (RCMs), and general circulation models (GCMs) is averaged over the state of California (CA) and compared. Several averaging methodologies are considered and all are found to give similar values when model grid spacing is less than 3{sup o}. This suggests that CA is a reasonable size for regional intercomparisons using modern GCMs. Results show that reanalysis-forced RCMs tend to significantly overpredict CA precipitation. This appears to be due mainly to overprediction of extreme events; RCM precipitation frequency is generally underpredicted. Overprediction is also reflected in wintertime precipitation variability, which tends to be too high for RCMs on both daily and interannual scales. Wintertime precipitation in most (but not all) GCMs is underestimated. This is in contrast to previous studies based on global blended gauge/satellite observations which are shown here to underestimate precipitation relative to higher-resolution gauge-only datasets. Several GCMs provide reasonable daily precipitation distributions, a trait which doesn't seem tied to model resolution. GCM daily and interannual variability is generally underpredicted.

Caldwell, P M

2009-04-27T23:59:59.000Z

84

A dynamic term structure model of Central Bank policy  

E-Print Network [OSTI]

This thesis investigates the implications of explicitly modeling the monetary policy of the Central Bank within a Dynamic Term Structure Model (DTSM). We follow Piazzesi (2005) and implement monetary policy by including ...

Staker, Shawn W

2009-01-01T23:59:59.000Z

85

Dynamics of photoexcited carriers in monolayer epitaxial graphene probed by photoluminescence in the near-infrared region  

SciTech Connect (OSTI)

We investigate the dynamics of photoexcited carriers in a single monolayer graphene at room temperature in air by femtosecond time-resolved luminescence measurements. The luminescence kinetics observed in the near-infrared region from 0.7 to 0.9 eV are analyzed based on the two-temperature model describing the cooling of thermalized carriers due to the carrier-optical-phonon coupling. The observed luminescence kinetics are well reproduced by the model, though the calculated electron temperature increases only to ?420 K at the maximum, which is much lower than the optical phonon energies. This indicates the predominance of optical phonons over acoustic phonons in the carrier-phonon interaction even at a temperature of ?400 K.

Koyama, Takeshi [Department of Applied Physics, Nagoya University, Chikusa, Nagoya 464-8603 (Japan); Ito, Yoshito; Yoshida, Kazuma [Graduate School of Engineering Sciences, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan); Ago, Hiroki [Graduate School of Engineering Sciences, Kyushu University, Kasuga, Fukuoka 816-8580, Japan and Institute for Materials Chemistry and Engineering, Kyushu University, Kasuga, Fukuoka 816-8580 (Japan); Nakamura, Arao [Department of Applied Physics, Nagoya University, Chikusa, Nagoya 464-8603, Japan and Toyota Physical and Chemical Research Institute, Nagakute, Aichi 480-1192 (Japan)

2013-12-04T23:59:59.000Z

86

Ecosystem dynamics at six contrasting sites: a generic modelling study  

Science Journals Connector (OSTI)

A pelagic marine ecosystem simulation model ERSEM-2004, developed from the European Regional Seas Ecosystem Model (ERSEM II), is presented along with a parameter set applicable to six highly contrasting sites, ranging from a temperate mixed shelf station to a permanently stratified tropical deep-ocean station. The physical characteristics are simulated by direct coupling to a 1D vertically resolved turbulence model, parameterised for each site. A mathematical description of the pelagic ecosystem model is presented. Additions to ERSEM II's well resolved community and decoupling of gross production and ambient nutrient concentration include variable carbon to chlorophyll ratios, coupling of bacterial production to nutrient availability, improved resolution of the organic particulate and dissolved fractions and developments to the mesozooplankton description. Comparison of seasonally depth resolved and integrated properties illustrates that the model produces a wide range of community dynamics and structures that can be plausibly related to variations in mixing, temperature, irradiance and nutrient supply. The spatial–temporal variability in key environmental indicators only partially correlates with the spatial–temporal variability in community structure (?0.75) between spatial–temporal variability in community structure (biomass) and function (production). ERSEM-2004 is shown to be a robust model that is capable of representing a range of systems commonly described in the marine system. Consequently, the model is proposed as a potential basis for an ecosystem-based management tool that may, with appropriate physical representation, be applied over large geographic and temporal scales with utility to both heuristic and predictive studies of the marine lower trophic levels.

J.C. Blackford; J.I. Allen; F.J. Gilbert

2004-01-01T23:59:59.000Z

87

O-regime dynamics and modeling in Tore Supra  

SciTech Connect (OSTI)

The regime of nonlinear temperature oscillations (O-regime), characteristic of noninductive discharges on Tore Supra [Equipe Tore Supra, Proceedings of the 12th International Conference on Plasma Physics and Controlled Nuclear Fusion Research, Nice, France, 1988 (International Atomic Energy Agency, Vienna, 1989), Vol. 1, p. 9], is investigated in its triggering and suppressing mechanism. This regime can be described by two nonlinearly coupled equations for the current density j(r) and the electron temperature T{sub e}(r) where the equation coefficients are functions of j and T{sub e} themselves. Both the integrated modeling code CRONOS[V. Basiuk et al., Nucl. Fusion 43, 822 (2003)] and a two-patch predator-prey system with diffusion and noise have been used and results have been compared to the experimental observations of the O-regime. A database of discharges is analyzed which features monotonic, flat, and reversed safety factor (q) profiles in order to characterize the action of external actuators on the regime dynamics with the widest generality. Electron cyclotron current drive and neutral beam injections have been used in order to induce localized perturbations in the total current profile j(r) as well as to change the plasma confinement conditions in the central region. Magnetic shear perturbations and modifications of the heat transport turn out to be the central parameters governing the dynamics of the O-regime.

Turco, F.; Giruzzi, G.; Imbeaux, F.; Udintsev, V. S.; Artaud, J. F.; Barana, O.; Dumont, R.; Mazon, D.; Segui, J.-L. [CEA-IRFM, 13108 St. Paul-les-Durance (France)

2009-06-15T23:59:59.000Z

88

Modeling dilute sediment suspension using large-eddy simulation with a dynamic mixed model  

E-Print Network [OSTI]

Modeling dilute sediment suspension using large-eddy simulation with a dynamic mixed model Yi Transport of suspended sediment in high Reynolds number channel flows Re=O 600 000 is simulated using large-eddy simulation along with a dynamic-mixed model DMM . Because the modeled sediment concentration is low

Fringer, Oliver B.

89

Subcycled dynamics in the Spectral Community Atmosphere Model, version 4  

SciTech Connect (OSTI)

To gain computational efficiency, a split explicit time integration scheme has been implemented in the CAM spectral Eulerian dynamical core. In this scheme, already present in other dynamical core options within the Community Atmosphere Model, version 4 (CAM), the fluid dynamics portion of the model is subcycled to allow a longer time step for the parameterization schemes. The physics parameterization of CAM is not subject to the stability restrictions of the fluid dynamics, and thus finer spatial resolutions of the model do not require the physics time step to be reduced. A brief outline of the subcycling algorithm implementation and resulting model efficiency improvement is presented. A discussion regarding the effect of the climate statistics derived from short model runs is provided.

Taylor, Mark [Sandia National Laboratories (SNL)] [Sandia National Laboratories (SNL); Evans, Katherine J [ORNL] [ORNL; Hack, James J [ORNL] [ORNL; Worley, Patrick H [ORNL] [ORNL

2010-01-01T23:59:59.000Z

90

The Mixing Time Evolution of Glauber Dynamics for the Mean-Field Ising Model  

E-Print Network [OSTI]

dynamics for the mean-?eld Ising model. http://arxiv. org/dynamics for the mean-?eld Ising model: cut-off, criticalDynamics for the Mean-Field Ising Model Jian Ding 1, , Eyal

Ding, Jian; Lubetzky, Eyal; Peres, Yuval

2009-01-01T23:59:59.000Z

91

Fibre Based Modeling of Wood Dynamics and Fracture  

E-Print Network [OSTI]

Fibre Based Modeling of Wood Dynamics and Fracture by Sean Meiji Sutherland B.Sc., The University for the simulation of the dynamics and fracturing char- acteristics of wood, specifically its anisotropic behaviour bundles of fibres. Additionally, we describe the conditions under which fracture occurs in the material

Bridson, Robert

92

Dynamic Modelling for Control of Fuel Cells Federico Zenith  

E-Print Network [OSTI]

Dynamic Modelling for Control of Fuel Cells Federico Zenith Sigurd Skogestad Department of Chemical Engineering Norwegian University of Science and Technology ( ntnu) Trondheim Abstract Fuel-cell dynamics have been investigated with a variable-resistance board applied to a high temperature polymer fuel cell

Skogestad, Sigurd

93

A New Motorcycle Simulator Platform: Mechatronics Design, Dynamics Modeling  

E-Print Network [OSTI]

A New Motorcycle Simulator Platform: Mechatronics Design, Dynamics Modeling and Control L. Nehaoua of these techniques to other simulators (cars and motorcycles) is possible but not direct. Indeed, the dynamics motorcycle driving simulators were build. The first prototype was developed by Honda in 1988

Paris-Sud XI, Université de

94

Improvement of snowpack simulations in a regional climate model  

SciTech Connect (OSTI)

To improve simulations of regional-scale snow processes and related cold-season hydroclimate, the Community Land Model version 3 (CLM3), developed by the National Center for Atmospheric Research (NCAR), was coupled with the Pennsylvania State University/NCAR fifth-generation Mesoscale Model (MM5). CLM3 physically describes the mass and heat transfer within the snowpack using five snow layers that include liquid water and solid ice. The coupled MM5–CLM3 model performance was evaluated for the snowmelt season in the Columbia River Basin in the Pacific Northwestern United States using gridded temperature and precipitation observations, along with station observations. The results from MM5–CLM3 show a significant improvement in the SWE simulation, which has been underestimated in the original version of MM5 coupled with the Noah land-surface model. One important cause for the underestimated SWE in Noah is its unrealistic land-surface structure configuration where vegetation, snow and the topsoil layer are blended when snow is present. This study demonstrates the importance of the sheltering effects of the forest canopy on snow surface energy budgets, which is included in CLM3. Such effects are further seen in the simulations of surface air temperature and precipitation in regional weather and climate models such as MM5. In addition, the snow-season surface albedo overestimated by MM5–Noah is now more accurately predicted by MM5–CLM3 using a more realistic albedo algorithm that intensifies the solar radiation absorption on the land surface, reducing the strong near-surface cold bias in MM5–Noah. The cold bias is further alleviated due to a slower snowmelt rate in MM5–CLM3 during the early snowmelt stage, which is closer to observations than the comparable components of MM5–Noah. In addition, the over-predicted precipitation in the Pacific Northwest as shown in MM5–Noah is significantly decreased in MM5 CLM3 due to the lower evaporation resulting from the longer snow duration.

Jin, J.; Miller, N.L.

2011-01-10T23:59:59.000Z

95

Application of Scale-Selective Data Assimilation to Regional Climate Modeling and Prediction  

Science Journals Connector (OSTI)

A method referred to as scale-selective data assimilation (SSDA) is designed to inject the large-scale components of the atmospheric circulation from a global model into a regional model to improve regional climate simulations and predictions. ...

Shiqiu Peng; Lian Xie; Bin Liu; Fredrick Semazzi

2010-04-01T23:59:59.000Z

96

Dynamic energy budget approaches for modelling organismal ageing  

Science Journals Connector (OSTI)

...quantitative approach. New York, NY: Harwood Academic...1928 The rate of living. New York, NY: Knopf. Ricklefs...A. L. M. 2010 Dynamic energy budget theory restores coherence...Nothobranchius furzeri as a new model system for aging studies...

2010-01-01T23:59:59.000Z

97

Applications of axial and radial compressor dynamic system modeling  

E-Print Network [OSTI]

The presented work is a compilation of four different projects related to axial and centrifugal compression systems. The projects are related by the underlying dynamic system modeling approach that is common in all of them. ...

Spakovszky, Zoltán S. (Zoltán Sándor), 1972-

2001-01-01T23:59:59.000Z

98

Dynamics of Ising models with damping J. M. Deutsch  

E-Print Network [OSTI]

Dynamics of Ising models with damping J. M. Deutsch Department of Physics, University of California Donostia, Spain Received 30 August 2007; published 28 March 2008 We show for the Ising model, both from a theoretical standpoint and for numerical efficiency. Ising models are perhaps the best

Deutsch, Josh

99

Global registration of dynamic range scans for articulated model reconstruction  

Science Journals Connector (OSTI)

We present the articulated global registration algorithm to reconstruct articulated 3D models from dynamic range scan sequences. This new algorithm aligns multiple range scans simultaneously to reconstruct a full 3D model from the geometry of these scans. ... Keywords: Range scanning, animation reconstruction, articulated model, nonrigid registration

Will Chang; Matthias Zwicker

2011-05-01T23:59:59.000Z

100

Cognitive Modeling Carsten Pfeffer Dynamical Systems Approaches to  

E-Print Network [OSTI]

Cognitive Modeling Carsten Pfeffer Dynamical Systems Approaches to Cognition Carsten Pfeffer Universität Bremen December 1st, 2014 December 1st, 2014 1/30 #12;Cognitive Modeling Carsten Pfeffer Introduction Physical Symbol Systems December 1st, 2014 2/30 #12;Cognitive Modeling Carsten Pfeffer

Bremen, Universität

Note: This page contains sample records for the topic "regional dynamics model" 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

COMPUTATIONAL FLUID DYNAMICS MODELING OF SOLID OXIDE FUEL CELLS  

E-Print Network [OSTI]

COMPUTATIONAL FLUID DYNAMICS MODELING OF SOLID OXIDE FUEL CELLS Ugur Pasaogullari and Chao-dimensional model has been developed to simulate solid oxide fuel cells (SOFC). The model fully couples current density operation. INTRODUCTION Solid oxide fuel cells (SOFC) are among possible candidates

102

New model describing the dynamical behaviour of penetration rates  

Science Journals Connector (OSTI)

We propose a hierarchical logistic equation as a model to describe the dynamical behaviour of a penetration rate of a prevalent stuff. In this model, a memory, how many people who already possess it a person who does not process it yet met, is considered, which does not exist in the logistic model. As an application, we apply this model to iPod sales data, and find that this model can approximate the data much better than the logistic equation.

Tohru Tashiro; Hiroe Minagawa; Michiko Chiba

2013-01-01T23:59:59.000Z

103

Developing Generic Dynamic Models for the 2030 Eastern Interconnection Grid  

SciTech Connect (OSTI)

The Eastern Interconnection Planning Collaborative (EIPC) has built three major power flow cases for the 2030 Eastern Interconnection (EI) based on various levels of energy/environmental policy conditions, technology advances, and load growth. Using the power flow cases, this report documents the process of developing the generic 2030 dynamic models using typical dynamic parameters. The constructed model was validated indirectly using the synchronized phasor measurements by removing the wind generation temporarily.

Kou, Gefei [ORNL; Hadley, Stanton W [ORNL; Markham, Penn N [ORNL; Liu, Yilu [ORNL

2013-12-01T23:59:59.000Z

104

Dynamic Analysis and Modeling of Jansen Mechanism  

Science Journals Connector (OSTI)

Abstract Theo Jansen mechanism is gaining wide spread popularity among legged robotics researchers due to its scalable design, energy efficiency, low payload to machine load ratio, bio-inspired locomotion, deterministic foot trajectory among others. In this paper, we present dynamic analysis of a four legged Theo Jansen link mechanism using projection method that results in constraint force and equivalent Lagrange's equation of motion necessary for any meaningful extension and/or optimization of this niche mechanism. Numerical simulations using MaTX is presented in conjunction with the dynamic analysis. This research sets a theoretical basis for future investigation into Theo Jansen mechanism.

Shunsuke Nansai; Mohan Rajesh Elara; Masami Iwase

2013-01-01T23:59:59.000Z

105

ERCOT's Dynamic Model of Wind Turbine Generators: Preprint  

SciTech Connect (OSTI)

By the end of 2003, the total installed wind farm capacity in the Electric Reliability Council of Texas (ERCOT) system was approximately 1 gigawatt (GW) and the total in the United States was about 5 GW. As the number of wind turbines installed throughout the United States increases, there is a greater need for dynamic wind turbine generator models that can properly model entire power systems for different types of analysis. This paper describes the ERCOT dynamic models and simulations of a simple network with different types of wind turbine models currently available.

Muljadi, E.; Butterfield, C. P.; Conto, J.; Donoho, K.

2005-08-01T23:59:59.000Z

106

Structure formation: Models, Dynamics and Status  

E-Print Network [OSTI]

The constraints on the models for the structure formation arising from various cosmological observations at different length scales are reviewed. The status of different models for structure formation is examined critically in the light of these observations.

T. Padmanabhan

1995-08-25T23:59:59.000Z

107

More dynamical models of our Galaxy  

Science Journals Connector (OSTI)

......rapidly at z 1kpc. In general sigma mirrors v , rising as v falls. The bottom-left...data have been interpreted with either Schwarzschild models (Cappellari et al. ) or models...with greater ease than is possible with Schwarzschild models and greater rigour than the Jeans......

James Binney

2012-10-21T23:59:59.000Z

108

Dynamic modelling for thermal micro-actuators using thermal networks  

E-Print Network [OSTI]

Dynamic modelling for thermal micro-actuators using thermal networks Beatriz L´opez-Wallea,1 and analytical calculations. Key words: Micro-actuators, Thermal modelling, Electrical analogy, Thermal network 1 and MicroMechatronic Systems Department (AS2M), 24 rue Alain Savary, 25000 Besan¸con, France Abstract

Paris-Sud XI, Université de

109

Dynamic physiological modeling for functional diffuse optical tomography  

E-Print Network [OSTI]

,c and David A. Boasa a Massachusetts General Hospital, Athinoula A. Martinos Center for Biomedical Imaging and brain that reflect competing metabolic demands and cardiovascular dynamics. The diffuse nature of near- namic response. In this paper, we present a linear state-space model for DOT analysis that models

110

Computational Modeling of Brain Dynamics during Repetitive Head Motions  

E-Print Network [OSTI]

Computational Modeling of Brain Dynamics during Repetitive Head Motions Igor Szczyrba School motions in traumatic scenarios that are as- sociated with severe brain injuries. Our results are based on the linear Kelvin-Voigt brain injury model, which treats the brain matter as a viscoelastic solid, and on our

Burtscher, Martin

111

2 J. MANDEL ET AL. DYNAMIC DATA DRIVEN WILDFIRE MODELING  

E-Print Network [OSTI]

2 J. MANDEL ET AL. DYNAMIC DATA DRIVEN WILDFIRE MODELING J. MANDELa , M. CHENa , J.L. COENb , C of Colorado Denver, Denver, CO 80217-3364, USA b National Center for Atmospheric Research, Boulder, CO 80307. A proposed system for real-time modeling of wildfires is described. The system involves numerical weather

Douglas, Craig C.

112

Numerical Modeling of Brain Dynamics in Traumatic Situations -Impulsive Translations  

E-Print Network [OSTI]

.S.A. Abstract We numerically model the brain dy- namics during and after impulsive head translations using brain injuries appear among boxers and shaken babies despite minimal rotations of their heads. Modeling head translations also helps understand the brain dynamics during head rotations about an arbitrary

Burtscher, Martin

113

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

114

Dynamic model order reduction for shipboard integrated power systems  

Science Journals Connector (OSTI)

The shipboard integrated power system is modeled by a system of differential-algebraic equations with dynamics having time constants varying from fractions of a second to several minutes. Control and simulation of naval shipboard power systems for different ... Keywords: electric ship, integrated power system, model order reduction, shipboard power system, singular perturbation

Sudipta Lahiri; Dagmar Niebur; Harry Kwatny; Gaurav Bajpai

2009-07-01T23:59:59.000Z

115

Modeling Equilibrium Dynamics of the Benguela Current System  

Science Journals Connector (OSTI)

The Regional Ocean Modeling System (ROMS) is used to systematically investigate equilibrium conditions and seasonal variations of the Benguela system at a resolution of 9 km, including both the large-scale offshore flow regime and the ...

Jennifer Veitch; Pierrick Penven; Frank Shillington

2010-09-01T23:59:59.000Z

116

DYNAMICAL MODEL OF AN EXPANDING SHELL  

SciTech Connect (OSTI)

Expanding blast waves are ubiquitous in many astronomical sources, such as supernova remnants, X-ray emitting binaries, and gamma-ray bursts. I consider here the dynamics of such an expanding blast wave, both in the adiabatic and the radiative regimes. As the blast wave collects material from its surroundings, it decelerates. A full description of the temporal evolution of the blast wave requires consideration of both the energy density and the pressure of the shocked material. The obtained equation is different from earlier works in which only the energy was considered. The solution converges to the familiar results in both the ultrarelativistic and the sub-relativistic (Newtonian) regimes.

Pe'er, Asaf [Harvard-Smithsonian Center for Astrophysics, MS-51, 60 Garden Street, Cambridge, MA 02138 (United States)

2012-06-10T23:59:59.000Z

117

Friction in a Model of Hamiltonian Dynamics  

E-Print Network [OSTI]

We study the motion of a heavy tracer particle weakly coupled to a dense ideal Bose gas exhibiting Bose-Einstein condensation. In the so-called mean-field limit, the dynamics of this system approaches one determined by nonlinear Hamiltonian evolution equations describing a process of emission of Cerenkov radiation of sound waves into the Bose-Einstein condensate along the particle's trajectory. The emission of Cerenkov radiation results in a friction force with memory acting on the tracer particle and causing it to decelerate until it comes to rest.

Juerg Froehlich; Zhou Gang; Avy Soffer

2011-10-29T23:59:59.000Z

118

Modeling of Alpine Atmospheric Dynamics II  

E-Print Network [OSTI]

for large mesh sizes (x 20 km) to vertically redistribute heat and moisture in a grid column when model in a numerical model Convective cloud systems are not resolved if the mesh size of the grid is larger than small to treat convection as sub-grid scale process but too large to treat it explicitly For example

Gohm, Alexander

119

Dynamic force spectroscopy on multiple bonds: experiments and model  

E-Print Network [OSTI]

We probe the dynamic strength of multiple biotin-streptavidin adhesion bonds under linear loading using the biomembrane force probe setup for dynamic force spectroscopy. Measured rupture force histograms are compared to results from a master equation model for the stochastic dynamics of bond rupture under load. This allows us to extract the distribution of the number of initially closed bonds. We also extract the molecular parameters of the adhesion bonds, in good agreement with earlier results from single bond experiments. Our analysis shows that the peaks in the measured histograms are not simple multiples of the single bond values, but follow from a superposition procedure which generates different peak positions.

T. Erdmann; S. Pierrat; P. Nassoy; U. S. Schwarz

2007-12-18T23:59:59.000Z

120

Post-Systolic Thickening in Ischaemic Myocardium: A Simple Mathematical Model for Simulating Regional Deformation  

Science Journals Connector (OSTI)

We present a one-dimensional mathematical model to explain changes in regional radial myocardial deformation during ischaemia. The model makes use of cellular contraction properties of normal and ischaemic myocytes extracted from an animal model of induced ...

Piet Claus; Bart Bijnens; Frank Weidemann; Christoph Dommke; Virginie Bito; Frank Heinzel; Karin Sipido; Ivan De Scheerder; Frank E. Rademakers; George R. Sutherland

2001-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "regional dynamics model" 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

Modeling-Computer Simulations At Northern Basin & Range Region...  

Open Energy Info (EERE)

Unknown References Glenn Biasi, Leiph Preston, Ileana Tibuleac (2009) Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators In The Western Great Basin...

122

Modeling-Computer Simulations At Nw Basin & Range Region (Biasi...  

Open Energy Info (EERE)

Unknown References Glenn Biasi, Leiph Preston, Ileana Tibuleac (2009) Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators In The Western Great Basin...

123

Contour dynamics model for electric discharges  

Science Journals Connector (OSTI)

We present an effective contour model for electrical discharges deduced as the asymptotic limit of the minimal streamer model for the propagation of electric discharges, in the limit of small electron diffusion. The incorporation of curvature effects to the velocity propagation and not to the boundary conditions is a feature and makes it different from the classical Laplacian growth models. The dispersion relation for a nonplanar two-dimensional discharge is calculated. The development and propagation of fingerlike patterns are studied and their main features quantified.

M. Arrayás, M. A. Fontelos, and C. Jiménez

2010-03-18T23:59:59.000Z

124

Modeling Infection with Multi-agent Dynamics  

E-Print Network [OSTI]

Developing the ability to comprehensively study infections in small populations enables us to improve epidemic models and better advise individuals about potential risks to their health. We currently have a limited ...

Dong, Wen

2012-01-01T23:59:59.000Z

125

THE WISCONSIN DYNAMICAL/MICROPHYSICAL MODEL  

E-Print Network [OSTI]

, assumed uniform, is dictated by quasi-compressible computational stability requirements. The computational an ellipsoidal warm bubble in the lower central part of the model domain, with the same relative humidities

Wang, Pao K.

126

Modeling-Computer Simulations At Northern Basin & Range Region (Biasi, Et  

Open Energy Info (EERE)

Modeling-Computer Simulations At Northern Basin & Range Region (Biasi, Et Modeling-Computer Simulations At Northern Basin & Range Region (Biasi, Et Al., 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Northern Basin & Range Region (Biasi, Et Al., 2009) Exploration Activity Details Location Northern Basin and Range Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful regional reconnaissance DOE-funding Unknown References Glenn Biasi, Leiph Preston, Ileana Tibuleac (2009) Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators In The Western Great Basin Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_At_Northern_Basin_%26_Range_Region_(Biasi,_Et_Al.,_2009)&oldid=40142

127

Crustal structure of the south-central Andes Cordillera and backarc region from regional waveform modelling  

Science Journals Connector (OSTI)

......phase PmpSmp with long period energy but smaller amplitudes at regional...reported by the local networks in Argentina (INPRES) and Chile (SSN...histogram shows the seismic energy (in 106 J) released in the...coverage due to the Chile and Argentina seismic networks, so it is......

P. Alvarado; S. Beck; G. Zandt

2007-08-01T23:59:59.000Z

128

Dynamics of Ising models with damping  

Science Journals Connector (OSTI)

We show for the Ising model that it is possible to construct a discrete time stochastic model analogous to the Langevin equation that incorporates an arbitrary amount of damping. It is shown to give the correct equilibrium statistics and is then used to investigate nonequilibrium phenomena, in particular, magnetic avalanches. The value of damping can greatly alter the shape of hysteresis loops, and for small damping and high disorder, the morphology of large avalanches can be drastically affected. Small damping also alters the size distribution of avalanches at criticality.

J. M. Deutsch and A. Berger

2008-03-28T23:59:59.000Z

129

CSAW: a dynamical model of protein folding  

E-Print Network [OSTI]

CSAW (conditioned self-avoiding walk) is a model of protein folding that combines SAW (self-avoiding walk) with Monte-Carlo. It simulates the Brownian motion of a chain molecule in the presence of interactions, both among chain residues, and with the environment. In a first model that includes the hydrophobic effect and hydrogen bonding, a chain of 30 residues folds into a native state with stable secondary and tertiary structures. The process starts with a rapid collapse into an intermediate "molten globule", which slowly decays into the native state afer a relatively long quiescent period. The behavior of the radius of gyration mimics experimental data.

Kerson Huang

2006-01-12T23:59:59.000Z

130

Clustering properties of dynamical dark energy models  

SciTech Connect (OSTI)

We provide a generic but physically clear discussion of the clustering properties of dark energy models. We explicitly show that in quintessence-type models the dark energy fluctuations, on scales smaller than the Hubble radius, are of the order of the perturbations to the Newtonian gravitational potential, hence necessarily small on cosmological scales. Moreover, comparable fluctuations are associated with different gauge choices. We also demonstrate that the often used homogeneous approximation is unrealistic, and that the so-called dark energy mutation is a trivial artifact of an effective, single fluid description. Finally, we discuss the particular case where the dark energy fluid is nonminimally coupled to dark matter.

Avelino, P. P.; Beca, L. M. G. [Centro de Fisica do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Departamento de Fisica da Faculdade de Ciencias da Universidade do Porto, Rua do Campo Alegre 687, 4169-007 Porto (Portugal); Martins, C. J. A. P. [Centro de Astrofisica, Universidade do Porto, Rua das Estrelas s/n, 4150-762 Porto (Portugal); DAMTP, University of Cambridge, Wilberforce Road, Cambridge CB3 0WA (United Kingdom)

2008-05-15T23:59:59.000Z

131

Modeling-Computer Simulations At Nw Basin & Range Region (Biasi, Et Al.,  

Open Energy Info (EERE)

Biasi, Et Al., Biasi, Et Al., 2009) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Nw Basin & Range Region (Biasi, Et Al., 2009) Exploration Activity Details Location Northwest Basin and Range Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful regional reconnaissance DOE-funding Unknown References Glenn Biasi, Leiph Preston, Ileana Tibuleac (2009) Body Wave Tomography For Regional Scale Assessment Of Geothermal Indicators In The Western Great Basin Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_At_Nw_Basin_%26_Range_Region_(Biasi,_Et_Al.,_2009)&oldid=401461" Categories: Exploration Activities DOE Funded

132

EMERGING DIMMINGS OF ACTIVE REGIONS OBSERVED BY THE SOLAR DYNAMICS OBSERVATORY  

SciTech Connect (OSTI)

Using the observations from the Atmospheric Imaging Assembly and the Helioseismic and Magnetic Imager on board the Solar Dynamics Observatory, we statistically investigate the emerging dimmings (EDs) of 24 isolated active regions (IARs) from 2010 June to 2011 May. All the IARs show EDs in lower-temperature lines (e.g., 171 A) at their early emerging stages. Meanwhile, in higher temperature lines (e.g., 211 A), the ED regions brighten continuously. There are two types of EDs: fan-shaped and halo-shaped. There are 19 fan-shaped EDs and 5 halo-shaped ones. The EDs appear to be delayed by several to more than ten hours relative to the first emergence of the IARs. The shortest delay is 3.6 hr and the longest is 19.0 hr. The EDs last from 3.3 hr to 14.2 hr, with a mean duration of 8.3 hr. Before the appearance of the EDs, the emergence rate of the magnetic flux of the IARs is between 1.2 Multiplication-Sign 10{sup 19} Mx hr{sup -1} to 1.4 Multiplication-Sign 10{sup 20} Mx hr{sup -1}. The larger the emergence rate is, the shorter the delay time is. While the dimmings appear, the magnetic flux of the IARs ranges from 8.8 Multiplication-Sign 10{sup 19} Mx to 1.3 Multiplication-Sign 10{sup 21} Mx. These observations imply that the reconfiguration of the coronal magnetic fields due to reconnection between the newly emerging flux and the surrounding existing fields results in a new thermal distribution which leads to a dimming for the cooler channel (171 A) and brightening in the warmer channels.

Zhang Jun; Yang Shuhong [Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences, Beijing 100012 (China); Liu Yang; Sun Xudong, E-mail: zjun@nao.cas.cn, E-mail: shuhongyang@nao.cas.cn, E-mail: yliu@sun.stanford.edu, E-mail: xudong@sun.stanford.edu [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305-4085 (United States)

2012-12-01T23:59:59.000Z

133

Green Algae as Model Organisms for Biological Fluid Dynamics  

E-Print Network [OSTI]

In the past decade the volvocine green algae, spanning from the unicellular $Chlamydomonas$ to multicellular $Volvox$, have emerged as model organisms for a number of problems in biological fluid dynamics. These include flagellar propulsion, nutrient uptake by swimming organisms, hydrodynamic interactions mediated by walls, collective dynamics and transport within suspensions of microswimmers, the mechanism of phototaxis, and the stochastic dynamics of flagellar synchronization. Green algae are well suited to the study of such problems because of their range of sizes (from 10 $\\mu$m to several millimetres), their geometric regularity, the ease with which they can be cultured and the availability of many mutants that allow for connections between molecular details and organism-level behavior. This review summarizes these recent developments and highlights promising future directions in the study of biological fluid dynamics, especially in the context of evolutionary biology, that can take advantage of these remarkable organisms.

Raymond E. Goldstein

2014-09-08T23:59:59.000Z

134

Green Algae as Model Organisms for Biological Fluid Dynamics  

E-Print Network [OSTI]

In the past decade the volvocine green algae, spanning from the unicellular $Chlamydomonas$ to multicellular $Volvox$, have emerged as model organisms for a number of problems in biological fluid dynamics. These include flagellar propulsion, nutrient uptake by swimming organisms, hydrodynamic interactions mediated by walls, collective dynamics and transport within suspensions of microswimmers, the mechanism of phototaxis, and the stochastic dynamics of flagellar synchronization. Green algae are well suited to the study of such problems because of their range of sizes (from 10 $\\mu$m to several millimetres), their geometric regularity, the ease with which they can be cultured and the availability of many mutants that allow for connections between molecular details and organism-level behavior. This review summarizes these recent developments and highlights promising future directions in the study of biological fluid dynamics, especially in the context of evolutionary biology, that can take advantage of these re...

Goldstein, Raymond E

2014-01-01T23:59:59.000Z

135

High-frequency absorption of the dynamic mixed state in the surface superconductivity region  

SciTech Connect (OSTI)

We analyze the absorption of a high-frequency electromagnetic field in the type II superconductor Pb{sub 0.8}In{sub 0.2} in magnetic fields H{sub c2} < H < H{sub c3}. The absorption component proportional to the rate of variation of the external magnetic field is detected. We assume that this absorption component is associated with the dynamic mixed state of the superconducting shell containing 2D magnetic flux vortices (Kulik vortices). The motion of these vortices under the action of the critical current ensures the required difference between the external and internal magnetic inductions of the superconducting shell upon a change in the external magnetic field. This model correctly describes the observed behavior of absorption of rf electromagnetic radiation.

Berezin, V. A., E-mail: berezin@iptm.ru; Tulin, V. A., E-mail: tulin@iptm.ru [Russian Academy of Sciences, Institute of Microelectronics Technology and High-Purity Materials (Russian Federation)

2013-03-15T23:59:59.000Z

136

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

137

The Social Dynamics of Economic Performance: Innovation and Creativity in City-Regions Newfoundland and Labrador Project Preliminary Findings St. John's, Clarenville, Corner Brook & Labrador West  

E-Print Network [OSTI]

The Social Dynamics of Economic Performance: Innovation and Creativity in City-Regions Newfoundland.......................................................4! INNOVATION AND CREATIVITY IN CITY-REGIONS ............................................................................6! INNOVATION AND CREATIVITY IN SMALL CITIES ON THE PERIPHERY

deYoung, Brad

138

Ad hoc continuum-atomistic thermostat for modeling heat flow in molecular dynamics simulations  

E-Print Network [OSTI]

Ad hoc continuum-atomistic thermostat for modeling heat flow in molecular dynamics simulations J 2004) An ad hoc thermostating procedure that couples a molecular dynamics (MD) simulation

Brenner, Donald W.

139

ASTRO-H White Paper - Plasma Diagnostic and Dynamics of the Galactic Center Region  

E-Print Network [OSTI]

The most characteristic high-energy phenomena in the Galactic center (GC) region is the presence of strong K-shell emission lines from highly ionized Si, S, Ar, Ca, Fe and Ni, which form the Galactic Center X-ray Emission (GCXE). These multiple lines suggest that the GCXE is composed of at least two plasmas with temperatures of ~1 and ~7 keV. The GCXE also exhibits the K-shell lines from neutral Si, S, Ar, Ca, Fe and Ni atoms. A debatable issue is the origin of the GCXE plasma; whether it is a diffuse plasma or integrated emission of many unresolved point sources such as cataclysmic variables and active binaries. Detailed spectroscopy for these lines may provide a reliable picture of the GCXE plasma. The origin of the K-shell lines from neutral atoms is most likely the fluorescence by X-rays from a putative past flare of Sgr A*. Therefore ASTRO-H may provide unprecedented data for the past light curve of Sgr A*. All these lines may provide key information for the dynamics of the GCXE, using possible Doppler s...

Koyama, K; Nobukawa, M; Uchiyama, H; Nakashima, S; Aharonian, F; Chernyakova, M; Ichinohe, Y; Nobukawa, K K; Maeda, Y; Matsumoto, H; Murakami, H; Ricci, C; Stawarz, L; Tanaka, T; Tsuru, T G; Watanabe, S; Yamauchi, S; Yuasa, T

2014-01-01T23:59:59.000Z

140

HOMOLOGOUS EXTREME ULTRAVIOLET WAVES IN THE EMERGING FLUX REGION OBSERVED BY THE SOLAR DYNAMICS OBSERVATORY  

SciTech Connect (OSTI)

Taking advantage of the high temporal and spatial resolution of the Solar Dynamics Observatory (SDO) observations, we present four homologous extreme ultraviolet (EUV) waves within 3 hr on 2010 November 11. All EUV waves emanated from the same emerging flux region (EFR), propagated in the same direction, and were accompanied by surges, weak flares, and faint coronal mass ejections (CMEs). The waves had the basically same appearance in all EUV wavebands of the Atmospheric Imaging Assembly on SDO. The waves propagated at constant velocities in the range of 280-500 km s{sup -1}, with little angular dependence, which indicated that the homologous waves could be likely interpreted as fast-mode waves. The waves are supposed to likely involve more than one driving mechanism, and it was most probable that the waves were driven by the surges, due to their close timing and location relations. We also propose that the homologous waves were intimately associated with the continuous emergence and cancellation of magnetic flux in the EFR, which could supply sufficient energy and trigger the onsets of the waves.

Zheng Ruisheng; Jiang Yunchun; Yang Jiayan; Bi Yi; Hong Junchao; Yang, B.; Yang Dan, E-mail: zhrsh@ynao.ac.cn [National Astronomical Observatories/Yunnan Observatory, Chinese Academy of Sciences, Kunming 650011 (China)

2012-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "regional dynamics model" 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

Scaling up of Carbon Exchange Dynamics from AmeriFlux Sites to a Super-Region in the Eastern United States  

SciTech Connect (OSTI)

The primary objective of this project was to evaluate carbon exchange dynamics across a region of North America between the Great Plains and the East Coast. This region contains about 40 active carbon cycle research (AmeriFlux) sites in a variety of climatic and landuse settings, from upland forest to urban development. The core research involved a scaling strategy that uses measured fluxes of CO{sub 2}, energy, water, and other biophysical and biometric parameters to train and calibrate surface-vegetation-atmosphere models, in conjunction with satellite (MODIS) derived drivers. To achieve matching of measured and modeled fluxes, the ecosystem parameters of the models will be adjusted to the dynamically variable flux-tower footprints following Schmid (1997). High-resolution vegetation index variations around the flux sites have been derived from Landsat data for this purpose. The calibrated models are being used in conjunction with MODIS data, atmospheric re-analysis data, and digital land-cover databases to derive ecosystem exchange fluxes over the study domain.

Hans Peter Schmid; Craig Wayson

2009-05-05T23:59:59.000Z

142

A Dynamical Model of Plasma Turbulence in the Solar Wind  

E-Print Network [OSTI]

A dynamical approach, rather than the usual statistical approach, is taken to explore the physical mechanisms underlying the nonlinear transfer of energy, the damping of the turbulent fluctuations, and the development of coherent structures in kinetic plasma turbulence. It is argued that the linear and nonlinear dynamics of Alfven waves are responsible, at a very fundamental level, for some of the key qualitative features of plasma turbulence that distinguish it from hydrodynamic turbulence, including the anisotropic cascade of energy and the development of current sheets at small scales. The first dynamical model of kinetic turbulence in the weakly collisional solar wind plasma that combines self-consistently the physics of Alfven waves with the development of small-scale current sheets is presented and its physical implications are discussed. This model leads to a simplified perspective on the nature of turbulence in a weakly collisional plasma: the nonlinear interactions responsible for the turbulent casca...

Howes, G G

2015-01-01T23:59:59.000Z

143

Modeling Dynamic Landscapes in Open Source GIS  

E-Print Network [OSTI]

differencing, per-cell statistics: core, envelope, rate of change Space-Time voxel model V o lu m e s S u rf a c e s L in e s 2011 2004 1999 Helena Mitasova, NCSU DEM processing Series of point clouds interpolated to 0.3m-1m DEMs Systematic errors... to Doug Newcomb and Hope Morgan for sharing the data RTKGPS 2001 Lidar 0.2m lower Helena Mitasova, NCSU Nags Head Raster-based analysis Core surface z-min for each cell Envelope surface z-max for each cell Shoreline band: defined by shoreline from core...

Mitasova, Helena

2013-11-20T23:59:59.000Z

144

Wind Energy Applications of Unified and Dynamic Turbulence Models  

E-Print Network [OSTI]

Wind Energy Applications of Unified and Dynamic Turbulence Models Stefan Heinz and Harish Gopalan applicable as a low cost alternative. 1 Introduction There is a growing interest in using wind energy suggests the possibility of providing 20% of the electricity in the U.S. by wind energy in 2030

Heinz, Stefan

145

A Bayesian Dynamic Model for Influenza Surveillance Paola Sebastiani  

E-Print Network [OSTI]

by the increasing number of outbreaks caused by the H5N1 bird-flu strain [10]. Because influenza viruses changeA Bayesian Dynamic Model for Influenza Surveillance Paola Sebastiani Kenneth D Mandl Peter, the growing fear of an influenza pandemic and the recent shortage of flu vaccine highlight the need

Szolovits, Peter

146

Multiscale modeling of polystyrene dynamics in different environments  

E-Print Network [OSTI]

Multiscale modeling of polystyrene dynamics in different environments Qi Sun1 , Florence Pon1 simulations can address not only the average properties of the system but also the distribution over any component in their neighborhood and vice versa. The simulation temperature of 450 K is chosen to be above

Faller, Roland

147

A Model for Dynamic Reconfiguration in Service-oriented Architectures  

E-Print Network [OSTI]

A Model for Dynamic Reconfiguration in Service-oriented Architectures Jos´e Luiz Fiadeiro1 and Ant of service-oriented applications goes be- yond what is currently addressed by existing architecture of service-oriented applications. 1 Introduction Several architectural aspects arise from service-oriented

Lopes, Antónia

148

DYNAMIC MODELLING OF AUTONOMOUS POWER SYSTEMS INCLUDING RENEWABLE POWER SOURCES.  

E-Print Network [OSTI]

(thermal, gas, diesel) and renewable (hydro, wind) power units. The objective is to assess the impact - that have a special dynamic behaviour, and the wind turbines. Detailed models for each one of the power system components are developed. Emphasis is given in the representation of different hydro power plant

Paris-Sud XI, Université de

149

Dynamic Modeling and Recipe Optimization of Polyether Polyol Processes  

E-Print Network [OSTI]

Dynamic Modeling and Recipe Optimization of Polyether Polyol Processes Fall 2012 EWO Meeting Yisu Monomer Reactor Basic procedures Starters are first mixed with catalyst in the liquid phase Alkylene oxides in the liquid phase are fed in controlled rates The reactor temperature is controlled by the heat

Grossmann, Ignacio E.

150

FRW Cosmological model with Modified Chaplygin Gas and Dynamical System  

E-Print Network [OSTI]

The Friedmann-Robertson-Walker(FRW) model with dynamical Dark Energy(DE) in the form of modified Chaplygin gas(MCG) has been investigated. The evolution equations are reduced to an autonomous system on the two dimensional phase plane and it can be interpreted as the motion of the particle in an one dimensional potential.

Nairwita Mazumder; Ritabrata Biswas; Subenoy Chakraborty

2011-06-23T23:59:59.000Z

151

Reverse Audio Engineering: Model-Based Inversion of Dynamic Range  

E-Print Network [OSTI]

1 Reverse Audio Engineering: Model-Based Inversion of Dynamic Range Compression Stanislaw Gorlow, Graduate Student Member, IEEE and Joshua D. Reiss, Member, IEEE Abstract--Reverse audio engineering so far, reverse audio engineering. I. INTRODUCTION SOUND or audio engineering is an established discipline

152

Simulation of a Polar Low Case in the North Atlantic with different regional numerical models  

E-Print Network [OSTI]

Matthias Zahn, Hans von Storch University of Hamburg/ GKSS, Matthias.Zahn@gkss.de ABSTRACT In this paper (REgional MOdel) and CLM (CLimate Model) simulations performed at the GKSS with spectral nudging (Feser et

Zahn, Matthias

153

Regional Frequency Analysis at Ungauged Sites with the Generalized Additive Model  

Science Journals Connector (OSTI)

The log-linear regression model is one of the most commonly used models to estimate flood quantiles at ungauged sites within the regional frequency analysis (RFA) framework. However, hydrological processes are naturally complex in several aspects ...

F. Chebana; C. Charron; T. B. M. J. Ouarda; B. Martel

2014-12-01T23:59:59.000Z

154

A Diagnostic Analysis of a Long-Term Regional Air Pollutant Transport Model  

Science Journals Connector (OSTI)

Predicted concentrations from the Regional Air Pollutant Transport (RAPT) model are compared with the corresponding observed values of sulfate, and the results used to define strengths and weaknesses in the model formulation.

Daniel J. McNaughton; Carl M. Berkowitz; Robert C. Williams

1981-07-01T23:59:59.000Z

155

The Regional Ocean Modeling System (ROMS) 4-dimensional variational data assimilation systems  

E-Print Network [OSTI]

The Regional Ocean Modeling System (ROMS) 4-dimensional variational data assimilation systems Part during ocean data assimilation was explored when the Regional Ocean Modeling System (ROMS) 4-dimensional. This is the third part of a three part series describing the ROMS 4D- Var systems. Ã? 2011 Elsevier Ltd. All rights

Costa, Daniel P.

156

The Regional Ocean Modeling System (ROMS) 4-dimensional variational data assimilation systems  

E-Print Network [OSTI]

The Regional Ocean Modeling System (ROMS) 4-dimensional variational data assimilation systems Part Article history: Available online xxxx a b s t r a c t The Regional Ocean Modeling System (ROMS) 4 of the various components of ROMS 4D-Var. In par- ticular, we present a comparison of three approaches to 4D

Costa, Daniel P.

157

Multi-scale Ensemble Modeling of Modular Proteins with Intrinsically Disordered Linker Regions: Application to p53  

Science Journals Connector (OSTI)

Abstract In eukaryotic proteins, intrinsically disordered regions (IDRs) are ubiquitous and often exist in linker regions that flank the functional domains of modular proteins, regulating their functions. For detailed structural ensemble modeling of IDRs, we propose a multiscale method for \\{IDRs\\} that possess significant long-range order in modular proteins and apply it to the eukaryotic transcription factor p53 as an example. First, we performed all-atom (AA) molecular dynamics (MD) simulations of the explicitly solvated p53 linker region, without experimental restraint terms, finding fractional long-range contacts within the linker. Second, we fed this AA MD ensemble into a coarse-grained (CG) model, finding an optimal set of contact potentials. The optimized CG MD simulations reproduced the contact probability map from the AA MD simulations. Finally, we performed the CG MD simulation of the tetrameric p53 fragments including the core domains, the linker, and the tetramerization domain. Using the obtained ensemble, we theoretically calculated the small angle x-ray scattering (SAXS) profile of this fragment. The obtained SAXS profile agrees well with the experiment. We also found that the long-range contacts in the p53 linker region are required to reproduce the experimental SAXS profile. The developed framework in which we calculate the long-range contact probability map from the AA MD simulation and incorporate it to the CG model can be applied to broad range of IDRs.

Tsuyoshi Terakawa; Junichi Higo; Shoji Takada

2014-01-01T23:59:59.000Z

158

Model equations in rarefied gas dynamics: Viscous-slip and thermal-slip coefficients  

E-Print Network [OSTI]

Model equations in rarefied gas dynamics: Viscous-slip and thermal-slip coefficients C. E. Siewert-slip and the thermal-slip coefficients in rarefied gas dynamics. More specifically, the BGK model, the S model In reviewing numerous papers devoted to model equa- tions in rarefied gas dynamics, we have found no definitive

Siewert, Charles E.

159

Coupling Lattice Boltzmann and Molecular Dynamics models for dense fluids  

E-Print Network [OSTI]

We propose a hybrid model, coupling Lattice Boltzmann and Molecular Dynamics models, for the simulation of dense fluids. Time and length scales are decoupled by using an iterative Schwarz domain decomposition algorithm. The MD and LB formulations communicate via the exchange of velocities and velocity gradients at the interface. We validate the present LB-MD model in simulations of flows of liquid argon past and through a carbon nanotube. Comparisons with existing hybrid algorithms and with reference MD solutions demonstrate the validity of the present approach.

A. Dupuis; E. M. Kotsalis; P. Koumoutsakos

2006-10-27T23:59:59.000Z

160

Modeling-Computer Simulations At Northern Basin & Range Region (Pritchett,  

Open Energy Info (EERE)

Modeling-Computer Simulations At Northern Basin & Range Region (Pritchett, Modeling-Computer Simulations At Northern Basin & Range Region (Pritchett, 2004) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Northern Basin & Range Region (Pritchett, 2004) Exploration Activity Details Location Northern Basin and Range Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness not indicated DOE-funding Unknown References J. W. Pritchett (2004) Finding Hidden Geothermal Resources In The Basin And Range Using Electrical Survey Techniques- A Computational Feasibility Study Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_At_Northern_Basin_%26_Range_Region_(Pritchett,_2004)&oldid=401423"

Note: This page contains sample records for the topic "regional dynamics model" 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

Data-based Construction of Convex Region Surrogate (CRS) Models  

E-Print Network [OSTI]

University Arul Sundaramoorthy, Jose M. Pinto Praxair Inc., Business and Supply Chain Optimization R Model of an Industrial Process. Real process data drawn from a Praxair plant Set 1 0.900 0.062 0

Grossmann, Ignacio E.

162

Coping with uncertain dynamics in visual tracking : redundant state models and discrete search methods  

E-Print Network [OSTI]

A model of the world dynamics is a vital part of any tracking algorithm. The observed world can exhibit multiple complex dynamics at different spatio-temporal scales. Faithfully modeling all motion constraints in a ...

Taycher, Leonid

2006-01-01T23:59:59.000Z

163

A Groundwater Dynamic Simulation Model: Application to the Upper San Pedro Basin  

E-Print Network [OSTI]

A Groundwater Dynamic Simulation Model: Application to the Upper San Pedro Basin Report Prepared by using tools such as tracers to determine groundwater travel times and this dynamic simulation modeling

Fay, Noah

164

Modeling-Computer Simulations At General Us Region (Goff & Decker, 1983) |  

Open Energy Info (EERE)

Us Region (Goff & Decker, 1983) Us Region (Goff & Decker, 1983) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At General Us Region (Goff & Decker, 1983) Exploration Activity Details Location General Us Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes Review and identification of 24 potential sites for EGS development across the U.S., as well as modeling of the representative geologic systems in which promising EGS sites occur. References Fraser Goff, Edward R. Decker (1983) Candidate Sites For Future Hot Dry Rock Development In The United States Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_At_General_Us_Region_(Goff_%26_Decker,_1983)&oldid=38761

165

Lessons Learned from Alternative Transportation Fuels: Modeling Transition Dynamics  

Alternative Fuels and Advanced Vehicles Data Center [Office of Energy Efficiency and Renewable Energy (EERE)]

Lessons Learned from Lessons Learned from Alternative Transportation Fuels: Modeling Transition Dynamics C. Welch Technical Report NREL/TP-540-39446 February 2006 Lessons Learned from Alternative Transportation Fuels: Modeling Transition Dynamics C. Welch Prepared under Task Nos. HS04.2000 and HS06.1002 Technical Report NREL/TP-540-39446 February 2006 National Renewable Energy Laboratory 1617 Cole Boulevard, Golden, Colorado 80401-3393 303-275-3000 * www.nrel.gov Operated for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy by Midwest Research Institute * Battelle Contract No. DE-AC36-99-GO10337 NOTICE 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

166

Library for modeling and simulating the thermal dynamics of buildings  

Science Journals Connector (OSTI)

Today's buildings consume more energy than any other sector of the U.S. economy, including transportation and industry; a similar importance can be expected in most European countries. Due to the increased interest in saving energy in buildings, new dynamic thermal models that describe transient response in more flexible modeling languages become necessary. Traditional building simulation software (e.g. TRNSYS or Energy Plus) are based on almost intractable simulation codes, difficult to maintain and modify, that predict system quantities at fixed time intervals. More clear code, properly separated from the simulation environment, with variable time step solvers would be necessary for the assessment of HVAC system performance with quicker dynamics. Following some ideas from a previous building thermal behavior library, a new enhanced Modelica library for modeling buildings is presented. The library basically consists of a combination of lumped parameter models and one-dimensional distributed parameter models that interconnects with each other through a set of common interfaces. Object-oriented features like class parameters and multiple-inheritance are used to improve the library structure making it easy to read and use. Complex building topologies can be built-up from component blocks that result in physically correct compound models that can be efficiently simulated and studied in any Modelica simulation environment.

Juan I. Videla; Bernt Lie

2006-01-01T23:59:59.000Z

167

Dynamical Reduction Models: present status and future developments  

E-Print Network [OSTI]

We review the major achievements of the dynamical reduction program, showing why and how it provides a unified, consistent description of physical phenomena, from the microscopic quantum domain to the macroscopic classical one. We discuss the difficulties in generalizing the existing models in order to comprise also relativistic quantum field theories. We point out possible future lines of research, ranging from mathematical physics to phenomenology.

A. Bassi

2007-02-08T23:59:59.000Z

168

Modeling biofuel expansion effects on land use change dynamics  

Science Journals Connector (OSTI)

Increasing demand for crop-based biofuels, in addition to other human drivers of land use, induces direct and indirect land use changes (LUC). Our system dynamics tool is intended to complement existing LUC modeling approaches and to improve the understanding of global LUC drivers and dynamics by allowing examination of global LUC under diverse scenarios and varying model assumptions. We report on a small subset of such analyses. This model provides insights into the drivers and dynamic interactions of LUC (e.g., dietary choices and biofuel policy) and is not intended to assert improvement in numerical results relative to other works.Demand for food commodities are mostly met in high food and high crop-based biofuel demand scenarios, but cropland must expand substantially. Meeting roughly 25% of global transportation fuel demand by 2050 with biofuels requires >2 times the land used to meet food demands under a presumed 40% increase in per capita food demand. In comparison, the high food demand scenario requires greater pastureland for meat production, leading to larger overall expansion into forest and grassland. Our results indicate that, in all scenarios, there is a potential for supply shortfalls, and associated upward pressure on prices, of food commodities requiring higher land use intensity (e.g., beef) which biofuels could exacerbate.

Ethan Warner; Daniel Inman; Benjamin Kunstman; Brian Bush; Laura Vimmerstedt; Steve Peterson; Jordan Macknick; Yimin Zhang

2013-01-01T23:59:59.000Z

169

Best practices for system dynamics model design and construction with powersim studio.  

SciTech Connect (OSTI)

This guide addresses software quality in the construction of Powersim{reg_sign} Studio 8 system dynamics simulation models. It is the result of almost ten years of experience with the Powersim suite of system dynamics modeling tools (Constructor and earlier Studio versions). It is a guide that proposes a common look and feel for the construction of Powersim Studio system dynamics models.

Malczynski, Leonard A.

2011-06-01T23:59:59.000Z

170

Modeling-Computer Simulations At U.S. West Region (Laney, 2005) | Open  

Open Energy Info (EERE)

Modeling-Computer Simulations At U.S. West Region Modeling-Computer Simulations At U.S. West Region (Laney, 2005) Exploration Activity Details Location U.S. West Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful regional reconnaissance DOE-funding Unknown Notes Characterization and Conceptual Modeling of Magmatically-Heated and Deep-Circulation, High-Temperature Hydrothermal Systems in the Basin and Range and Cordilleran United States, Moore, Nash, Nemcok, Lutz, Norton, Kaspereit, Berard, van de Putte, Johnson and Deymonaz. Utilizing a wealth of formerly proprietary subsurface samples and datasets for exemplary high-temperature western U.S. geothermal systems, develop and publish detailed and refined new conceptual and numerical hydrothermal-history models of fundamental scientific import but, more importantly, of use to

171

Radiation-MHD models of elephant trunks and globules in H II regions  

E-Print Network [OSTI]

We study the formation and evolution of pillars of dense gas, known as elephant trunks, at the boundaries of H II regions, formed by shadowing of ionising radiation by dense clumps. The effects of magnetic fields on this process are investigated using 3D radiation-magnetohydrodynamics simulations. For a simulation in which an initially uniform magnetic field of strength |B|=50 uG is oriented perpendicular to the radiation propagation direction, the field is swept into alignment with the pillar during its dynamical evolution, in agreement with observations of the "Pillars of Creation" in M16, and of some cometary globules. This effect is significantly enhanced when the simulation is re-run with a weaker field of 18 uG. A stronger field with |B|=160 uG is sufficient to prevent this evolution completely, also significantly affecting the photoionisation process. Using a larger simulation domain it is seen that the pillar formation models studied in Mackey & Lim (2010) ultimately evolve to cometary structures ...

Mackey, Jonathan

2011-01-01T23:59:59.000Z

172

Modelling the e#ects of air pollution on health using Bayesian Dynamic Generalised Linear Models  

E-Print Network [OSTI]

Modelling the e#ects of air pollution on health using Bayesian Dynamic Generalised Linear Models (2004)). Large multi­city studies such as `Air pollution and health: a European approach' (APHEA across a number of US and European cities. Short­term e#ects of air pollution on health are estimated

Bath, University of

173

User Guide for PV Dynamic Model Simulation Written on PSCAD Platform  

SciTech Connect (OSTI)

This document describes the dynamic photovoltaic model developed by the National Renewable Energy Laboratory and is intended as a guide for users of these models.

Muljadi, E.; Singh, M.; Gevorgian, V.

2014-11-01T23:59:59.000Z

174

Eulerian hydrocode modeling of a dynamic tensile extrusion experiment (u)  

SciTech Connect (OSTI)

Eulerian hydrocode simulations utilizing the Mechanical Threshold Stress flow stress model were performed to provide insight into a dynamic extrusion experiment. The dynamic extrusion response of copper (three different grain sizes) and tantalum spheres were simulated with MESA, an explicit, 2-D Eulerian continuum mechanics hydrocode and compared with experimental data. The experimental data consisted of high-speed images of the extrusion process, recovered extruded samples, and post test metallography. The hydrocode was developed to predict large-strain and high-strain-rate loading problems. Some of the features of the features of MESA include a high-order advection algorithm, a material interface tracking scheme and a van Leer monotonic advection-limiting. The Mechanical Threshold Stress (MTS) model was utilized to evolve the flow stress as a function of strain, strain rate and temperature for copper and tantalum. Plastic strains exceeding 300% were predicted in the extrusion of copper at 400 m/s, while plastic strains exceeding 800% were predicted for Ta. Quantitative comparisons between the predicted and measured deformation topologies and extrusion rate were made. Additionally, predictions of the texture evolution (based upon the deformation rate history and the rigid body rotations experienced by the copper during the extrusion process) were compared with the orientation imaging microscopy measurements. Finally, comparisons between the calculated and measured influence of the initial texture on the dynamic extrusion response of tantalum was performed.

Burkett, Michael W [Los Alamos National Laboratory; Clancy, Sean P [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

175

Nicaragua-Low-Carbon Energy for Central America: Building a Regional Model  

Open Energy Info (EERE)

Nicaragua-Low-Carbon Energy for Central America: Building a Regional Model Nicaragua-Low-Carbon Energy for Central America: Building a Regional Model Jump to: navigation, search Name Nicaragua-Low-Carbon Energy for Central America: Building a Regional Model Agency/Company /Organization World Watch Institute Sector Energy Focus Area Renewable Energy Topics Background analysis, Implementation, Low emission development planning, Policies/deployment programs Website http://www.worldwatch.org/node Country Nicaragua Central America References Low-Carbon Energy for Central America: Building a Regional Model[1] Overview "This project will design a unified low-carbon development strategy for Central America through the use of renewable energy and energy efficiency maps, followed by technical, economic, and social feasibility studies for

176

Low-Carbon Energy for Central America: Building a Regional Model | Open  

Open Energy Info (EERE)

Low-Carbon Energy for Central America: Building a Regional Model Low-Carbon Energy for Central America: Building a Regional Model Jump to: navigation, search Name Low-Carbon Energy for Central America: Building a Regional Model Agency/Company /Organization World Watch Institute Sector Energy Focus Area Renewable Energy Topics Background analysis, Implementation, Low emission development planning, Policies/deployment programs Website http://www.worldwatch.org/node Country Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, Panama Central America, Central America, Central America, Central America, Central America, Central America, Central America References Low-Carbon Energy for Central America: Building a Regional Model[1] Overview "This project will design a unified low-carbon development strategy for

177

Honduras-Low-Carbon Energy for Central America: Building a Regional Model |  

Open Energy Info (EERE)

Honduras-Low-Carbon Energy for Central America: Building a Regional Model Honduras-Low-Carbon Energy for Central America: Building a Regional Model Jump to: navigation, search Name Honduras-Low-Carbon Energy for Central America: Building a Regional Model Agency/Company /Organization World Watch Institute Sector Energy Focus Area Renewable Energy Topics Background analysis, Implementation, Low emission development planning, Policies/deployment programs Website http://www.worldwatch.org/node Country Honduras Central America References Low-Carbon Energy for Central America: Building a Regional Model[1] Overview "This project will design a unified low-carbon development strategy for Central America through the use of renewable energy and energy efficiency maps, followed by technical, economic, and social feasibility studies for

178

Belize-Low-Carbon Energy for Central America: Building a Regional Model |  

Open Energy Info (EERE)

Belize-Low-Carbon Energy for Central America: Building a Regional Model Belize-Low-Carbon Energy for Central America: Building a Regional Model Jump to: navigation, search Name Belize-Low-Carbon Energy for Central America: Building a Regional Model Agency/Company /Organization World Watch Institute Sector Energy Focus Area Renewable Energy Topics Background analysis, Implementation, Low emission development planning, Policies/deployment programs Website http://www.worldwatch.org/node Country Belize Central America References Low-Carbon Energy for Central America: Building a Regional Model[1] Overview "This project will design a unified low-carbon development strategy for Central America through the use of renewable energy and energy efficiency maps, followed by technical, economic, and social feasibility studies for

179

Modeling-Computer Simulations At Nw Basin & Range Region (Laney, 2005) |  

Open Energy Info (EERE)

Modeling-Computer Simulations At Nw Basin & Range Region (Laney, 2005) Modeling-Computer Simulations At Nw Basin & Range Region (Laney, 2005) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Nw Basin & Range Region (Laney, 2005) Exploration Activity Details Location Northwest Basin and Range Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness not indicated DOE-funding Unknown Notes Assembling Crustal Geophysical Data for Geothermal Exploration in the Great Basin, Louie and Coolbaugh. We have compiled velocity information from sources in the literature, results of previous seismic experiments and earthquake-monitoring projects, and data donated from mining, geothermal, and petroleum companies. We also collected (May 2002 and August 2004) two

180

Costa Rica-Low-Carbon Energy for Central America: Building a Regional Model  

Open Energy Info (EERE)

Costa Rica-Low-Carbon Energy for Central America: Building a Regional Model Costa Rica-Low-Carbon Energy for Central America: Building a Regional Model Jump to: navigation, search Name Costa-Rica-Low-Carbon Energy for Central America: Building a Regional Model Agency/Company /Organization World Watch Institute Sector Energy Focus Area Renewable Energy Topics Background analysis, Implementation, Low emission development planning, Policies/deployment programs Website http://www.worldwatch.org/node Country Costa Rica Central America References Low-Carbon Energy for Central America: Building a Regional Model[1] Overview "This project will design a unified low-carbon development strategy for Central America through the use of renewable energy and energy efficiency maps, followed by technical, economic, and social feasibility studies for

Note: This page contains sample records for the topic "regional dynamics model" 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

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

182

High-Speed Extraction Model of Interest Region in the Parcel Image of Large Size  

Science Journals Connector (OSTI)

This paper deals with a model for the high-speed extraction of ROI (Region Of Interest) during the process of logistics transported on conveyor belt. The objective of this paper is to extract various ROIs from...

Moon-sung Park; Il-sook Kim; Eun-kyung Cho…

2005-01-01T23:59:59.000Z

183

Guatemala-Low-Carbon Energy for Central America: Building a Regional Model  

Open Energy Info (EERE)

Guatemala-Low-Carbon Energy for Central America: Building a Regional Model Guatemala-Low-Carbon Energy for Central America: Building a Regional Model Jump to: navigation, search Name Guatemala-Low-Carbon Energy for Central America: Building a Regional Model Agency/Company /Organization World Watch Institute Sector Energy Focus Area Renewable Energy Topics Background analysis, Implementation, Low emission development planning, Policies/deployment programs Website http://www.worldwatch.org/node Country Guatemala Central America References Low-Carbon Energy for Central America: Building a Regional Model[1] Overview "This project will design a unified low-carbon development strategy for Central America through the use of renewable energy and energy efficiency maps, followed by technical, economic, and social feasibility studies for

184

Dynamic ModelingDynamic Modeling the Electric Power Networkthe Electric Power Network  

E-Print Network [OSTI]

criteria to enter the wholesale market DEREGULATION PROCESS: FERC's Order 888 mandated the wheeling at the National Energy Modeling System/Annual Energy Outlook Conference, Washington, DC, March 10, 2003] #12

Oro, Daniel

185

Use of a dynamic simulation model to understand nitrogen cycling in the middle Rio Grande, NM.  

SciTech Connect (OSTI)

Water quality often limits the potential uses of scarce water resources in semiarid and arid regions. To best manage water quality one must understand the sources and sinks of both solutes and water to the river system. Nutrient concentration patterns can identify source and sink locations, but cannot always determine biotic processes that affect nutrient concentrations. Modeling tools can provide insight into these large-scale processes. To address questions about large-scale nitrogen removal in the Middle Rio Grande, NM, we created a system dynamics nitrate model using an existing integrated surface water--groundwater model of the region to evaluate our conceptual models of uptake and denitrification as potential nitrate removal mechanisms. We modeled denitrification in groundwater as a first-order process dependent only on concentration and used a 5% denitrification rate. Uptake was assumed to be proportional to transpiration and was modeled as a percentage of the evapotranspiration calculated within the model multiplied by the nitrate concentration in the water being transpired. We modeled riparian uptake as 90% and agricultural uptake as 50% of the respective evapotranspiration rates. Using these removal rates, our model results suggest that riparian uptake, agricultural uptake and denitrification in groundwater are all needed to produce the observed nitrate concentrations in the groundwater, conveyance channels, and river as well as the seasonal concentration patterns. The model results indicate that a total of 497 metric tons of nitrate-N are removed from the Middle Rio Grande annually. Where river nitrate concentrations are low and there are no large nitrate sources, nitrate behaves nearly conservatively and riparian and agricultural uptake are the most important removal mechanisms. Downstream of a large wastewater nitrate source, denitrification and agricultural uptake were responsible for approximately 90% of the nitrogen removal.

Meixner, Tom (University of Arizona, Tucson, AZ); Tidwell, Vincent Carroll; Oelsner, Gretchen (University of Arizona, Tucson, AZ); Brooks, Paul (University of Arizona, Tucson, AZ); Roach, Jesse D.

2008-08-01T23:59:59.000Z

186

Optimization of Fed-Batch Saccharomyces cereWisiae Fermentation Using Dynamic Flux Balance Models  

E-Print Network [OSTI]

ARTICLES Optimization of Fed-Batch Saccharomyces cereWisiae Fermentation Using Dynamic Flux Balance metabolism with dynamic mass balances on key extracellular species. Model-based dynamic optimization concentration profiles, and the final batch time are treated as decision variables in the dynamic optimization

Mountziaris, T. J.

187

Indicators to support the dynamic evaluation of air quality models  

Science Journals Connector (OSTI)

Abstract Air quality models are useful tools for the assessment and forecast of pollutant concentrations in the atmosphere. Most of the evaluation process relies on the “operational phase” or in other words the comparison of model results with available measurements which provides insight on the model capability to reproduce measured concentrations for a given application. But one of the key advantages of air quality models lies in their ability to assess the impact of precursor emission reductions on air quality levels. Models are then used in a dynamic mode (i.e. response to a change in a given model input data) for which evaluation of the model performances becomes a challenge. The objective of this work is to propose common indicators and diagrams to facilitate the understanding of model responses to emission changes when models are to be used for policy support. These indicators are shown to be useful to retrieve information on the magnitude of the locally produced impacts of emission reductions on concentrations with respect to the “external to the domain” contribution but also to identify, distinguish and quantify impacts arising from different factors (different precursors). In addition information about the robustness of the model results is provided. As such these indicators might reveal useful as first screening methodology to identify the feasibility of a given action as well as to prioritize the factors on which to act for an increased efficiency. Finally all indicators are made dimensionless to facilitate the comparison of results obtained with different models, different resolutions, or on different geographical areas.

P. Thunis; A. Clappier

2014-01-01T23:59:59.000Z

188

Dynamics of popstar record sales on phonographic market -- stochastic model  

E-Print Network [OSTI]

We investigate weekly record sales of the world's most popular 30 artists (2003-2013). Time series of sales have non-trivial kind of memory (anticorrelations, strong seasonality and constant autocorrelation decay within 120 weeks). Amount of artists record sales are usually the highest in the first week after premiere of their brand new records and then decrease to fluctuate around zero till next album release. We model such a behavior by discrete mean-reverting geometric jump diffusion (MRGJD) and Markov regime switching mechanism (MRS) between the base and the promotion regimes. We can built up the evidence through such a toy model that quantifies linear and nonlinear dynamical components (with stationary and nonstationary parameters set), and measure local divergence of the system with collective behavior phenomena. We find special kind of disagreement between model and data for Christmas time due to unusual shopping behavior. Analogies to earthquakes, product life-cycles, and energy markets will also be d...

Jarynowski, Amdrzej

2013-01-01T23:59:59.000Z

189

Dynamic Decision Making for Graphical Models Applied to Oil Exploration  

E-Print Network [OSTI]

We present a framework for sequential decision making in problems described by graphical models. The setting is given by dependent discrete random variables with associated costs or revenues. In our examples, the dependent variables are the potential outcomes (oil, gas or dry) when drilling a petroleum well. The goal is to develop an optimal selection strategy that incorporates a chosen utility function within an approximated dynamic programming scheme. We propose and compare different approximations, from simple heuristics to more complex iterative schemes, and we discuss their computational properties. We apply our strategies to oil exploration over multiple prospects modeled by a directed acyclic graph, and to a reservoir drilling decision problem modeled by a Markov random field. The results show that the suggested strategies clearly improve the simpler intuitive constructions, and this is useful when selecting exploration policies.

Martinelli, Gabriele; Hauge, Ragnar

2012-01-01T23:59:59.000Z

190

Dynamic validated model of a DFIG wind turbine  

Science Journals Connector (OSTI)

This paper presents the development and qualitative validation of a doubly-fed induction generator (DFIG) wind turbine model that is represented in terms of behaviour equations of each of the subsystems, mainly the turbine rotor, the drive train, the induction generator, the power converters and associated control systems and a protection system. Simulation results obtained from the models are compared to the field measurement data in a qualitative manner due to rotor wake and lack of ability of a single anemometer for adequate measurement of wind speed acting on the large surface of the rotor. It is concluded that the model is reasonably accurate and can hence be used for representing wind turbines in power system dynamics simulations.

Md. Ayaz Chowdhury; Nasser Hosseinzadeh; Weixiang Shen

2014-01-01T23:59:59.000Z

191

Explorations in combining cognitive models of individuals and system dynamics models of groups.  

SciTech Connect (OSTI)

This report documents a demonstration model of interacting insurgent leadership, military leadership, government leadership, and societal dynamics under a variety of interventions. The primary focus of the work is the portrayal of a token societal model that responds to leadership activities. The model also includes a linkage between leadership and society that implicitly represents the leadership subordinates as they directly interact with the population. The societal model is meant to demonstrate the efficacy and viability of using System Dynamics (SD) methods to simulate populations and that these can then connect to cognitive models depicting individuals. SD models typically focus on average behavior and thus have limited applicability to describe small groups or individuals. On the other hand, cognitive models readily describe individual behavior but can become cumbersome when used to describe populations. Realistic security situations are invariably a mix of individual and population dynamics. Therefore, the ability to tie SD models to cognitive models provides a critical capability that would be otherwise be unavailable.

Backus, George A.

2008-07-01T23:59:59.000Z

192

Regional and Global Data  

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

Products > Regional/Global Products > Regional/Global Regional and Global Data Biogeochemical Dynamics Data Regional and global biogeochemical dynamics data can be used to improve our understanding of the structure and function of various ecosystems; to enable prediction across spatial and temporal scales; and to parameterize and validate terrestrial ecosystem models. The ORNL DAAC compiles, archives, and distributes more than 150 products from the following projects: Climate Collections Hydroclimatology Collections ISLSCP II Project Net Primary Productivity (NPP) River Discharge (RIVDIS) Russian Land Cover (RLC) Soil Collections Vegetation Collections Vegetation-Ecosystem Modeling (VEMAP) Climate Collections Climate collections include measured and modeled values for variables such as temperature, precipitation, humidity, radiation, wind velocity, and

193

Towards a Simplified Dynamic Wake Model using POD Analysis  

E-Print Network [OSTI]

We apply the proper orthogonal decomposition (POD) to large eddy simulation data of a wind turbine wake in a turbulent atmospheric boundary layer. The turbine is modeled as an actuator disk. Our analyis mainly focuses on the question whether POD could be a useful tool to develop a simplified dynamic wake model. The extracted POD modes are used to obtain approximate descriptions of the velocity field. To assess the quality of these POD reconstructions, we define simple measures which are believed to be relevant for a sequential turbine in the wake such as the energy flux through a disk in the wake. It is shown that only a few modes are necessary to capture basic dynamical aspects of these measures even though only a small part of the turbulent kinetic energy is restored. Furthermore, we show that the importance of the individual modes depends on the measure chosen. Therefore, the optimal choice of modes for a possible model could in principle depend on the application of interest. We additionally present a pos...

Bastine, David; Wächter, Matthias; Peinke, Joachim

2014-01-01T23:59:59.000Z

194

A simple running model with rolling contact and its role as a template for dynamic locomotion on a hexapod robot  

Science Journals Connector (OSTI)

We report on the development of a robot's dynamic locomotion based on a template which fits the robot's natural dynamics. The developed template is a low degree-of-freedom planar model for running with rolling contact, which we call rolling spring loaded inverted pendulum (R-SLIP). Originating from a reduced-order model of the RHex-style robot with compliant circular legs, the R-SLIP model also acts as the template for general dynamic running. The model has a torsional spring and a large circular arc as the distributed foot, so during locomotion it rolls on the ground with varied equivalent linear stiffness. This differs from the well-known spring loaded inverted pendulum (SLIP) model with fixed stiffness and ground contact points. Through dimensionless steps-to-fall and return map analysis, within a wide range of parameter spaces, the R-SLIP model is revealed to have self-stable gaits and a larger stability region than that of the SLIP model. The R-SLIP model is then embedded as the reduced-order 'template' in a more complex 'anchor', the RHex-style robot, via various mapping definitions between the template and the anchor. Experimental validation confirms that by merely deploying the stable running gaits of the R-SLIP model on the empirical robot with simple open-loop control strategy, the robot can easily initiate its dynamic running behaviors with a flight phase and can move with similar body state profiles to those of the model, in all five testing speeds. The robot, embedded with the SLIP model but performing walking locomotion, further confirms the importance of finding an adequate template of the robot for dynamic locomotion.

Ke-Jung Huang; Chun-Kai Huang; Pei-Chun Lin

2014-01-01T23:59:59.000Z

195

Large scale molecular dynamics modeling of materials fabrication processes  

SciTech Connect (OSTI)

An atomistic molecular dynamics model of materials fabrication processes is presented. Several material removal processes are shown to be within the domain of this simulation method. Results are presented for orthogonal cutting of copper and silicon and for crack propagation in silica glass. Both copper and silicon show ductile behavior, but the atomistic mechanisms that allow this behavior are significantly different in the two cases. The copper chip remains crystalline while the silicon chip transforms into an amorphous state. The critical stress for crack propagation in silica glass was found to be in reasonable agreement with experiment and a novel stick-slip phenomenon was observed.

Belak, J.; Glosli, J.N.; Boercker, D.B.; Stowers, I.F.

1994-02-01T23:59:59.000Z

196

Dynamic Modeling and Adaptive Neural-Fuzzy Control for Nonholonomic Mobile Manipulators Moving on a Slope 1 Dynamic Modeling and Adaptive Neural-Fuzzy Control for  

E-Print Network [OSTI]

robots [7]. A robust fuzzy logic controller was devised for a robotic manipulator with uncertainties [8Dynamic Modeling and Adaptive Neural-Fuzzy Control for Nonholonomic Mobile Manipulators Moving on a Slope 1 Dynamic Modeling and Adaptive Neural-Fuzzy Control for Nonholonomic Mobile Manipulators Moving

Li, Yangmin

197

MODELLING RADIOIODINE DYNAMICS Modelling the Dynamics of Radioiodine in Dairy Cows  

E-Print Network [OSTI]

Department of Physiology & Environmental Science University of Nottingham Sutton Bonington LE12 5RD UK G for significant fecal excretion of radioiodine. The5 model is used to consider the effect of dietary stable iodine of iodine, in particular I-131, are important components in fallout from2 nuclear accidents

Crout, Neil

198

Modeling of Air-Fuel Ratio Dynamics of Gasoline Combustion Engine with ARX Network  

E-Print Network [OSTI]

DS-06-1351 Modeling of Air-Fuel Ratio Dynamics of Gasoline Combustion Engine with ARX Network Tomás dynamics of gasoline engines during transient operation. With a collection of input-output data measured;Modeling of Air-Fuel Ratio Dynamics of Gasoline Combustion Engine with ARX Network I. INTRODUCTION

Johansen, Tor Arne

199

Position Paper: A general framework for Dynamic Emulation Modelling in environmental problems  

Science Journals Connector (OSTI)

Emulation modelling is an effective way of overcoming the large computational burden associated with the process-based models traditionally adopted by the environmental modelling community. An emulator is a low-order, computationally efficient model ... Keywords: Dynamic emulation modelling, Metamodelling, Model complexity, Model reduction, Process-based models, Response surfaces

A. Castelletti; S. Galelli; M. Ratto; R. Soncini-Sessa; P. C. Young

2012-06-01T23:59:59.000Z

200

COLLABORATIVE RESEARCH: CONTINUOUS DYNAMIC GRID ADAPTATION IN A GLOBAL ATMOSPHERIC MODEL: APPLICATION AND REFINEMENT  

SciTech Connect (OSTI)

This project had goals of advancing the performance capabilities of the numerical general circulation model EULAG and using it to produce a fully operational atmospheric global climate model (AGCM) that can employ either static or dynamic grid stretching for targeted phenomena. The resulting AGCM combined EULAG's advanced dynamics core with the "physics" of the NCAR Community Atmospheric Model (CAM). Effort discussed below shows how we improved model performance and tested both EULAG and the coupled CAM-EULAG in several ways to demonstrate the grid stretching and ability to simulate very well a wide range of scales, that is, multi-scale capability. We leveraged our effort through interaction with an international EULAG community that has collectively developed new features and applications of EULAG, which we exploited for our own work summarized here. Overall, the work contributed to over 40 peer-reviewed publications and over 70 conference/workshop/seminar presentations, many of them invited. 3a. EULAG Advances EULAG is a non-hydrostatic, parallel computational model for all-scale geophysical flows. EULAG's name derives from its two computational options: EULerian (flux form) or semi-LAGrangian (advective form). The model combines nonoscillatory forward-in-time (NFT) numerical algorithms with a robust elliptic Krylov solver. A signature feature of EULAG is that it is formulated in generalized time-dependent curvilinear coordinates. In particular, this enables grid adaptivity. In total, these features give EULAG novel advantages over many existing dynamical cores. For EULAG itself, numerical advances included refining boundary conditions and filters for optimizing model performance in polar regions. We also added flexibility to the model's underlying formulation, allowing it to work with the pseudo-compressible equation set of Durran in addition to EULAG's standard anelastic formulation. Work in collaboration with others also extended the demonstrated range of validity of soundproof models, showing that they are more broadly applicable than some had previously thought. Substantial testing of EULAG included application and extension of the Jablonowski-Williamson baroclinic wave test - an archetype of planetary weather - and further analysis of multi-scale interactions arising from collapse of temperature fronts in both the baroclinic wave test and simulations of the Held-Suarez idealized climate. These analyses revealed properties of atmospheric gravity waves not seen in previous work and further demonstrated the ability of EULAG to simulate realistic behavior over several orders of magnitude of length scales. Additional collaborative work enhanced capability for modeling atmospheric flows with adaptive moving meshes and demonstrated the ability of EULAG to move into petascale computing. 3b. CAM-EULAG Advances We have developed CAM-EULAG in collaboration with former project postdoc, now University of Cape Town Assistant Professor, Babatunde Abiodun. Initial study documented good model performance in aqua-planet simulations. In particular, we showed that the grid adaptivity (stretching) implemented in CAM-EULAG allows higher resolution in selected regions without causing anomalous behavior such as spurious wave reflection. We then used the stretched-grid version to analyze simulated extreme precipitation events in West Africa, comparing the precipitation and event environment with observed behavior. The model simulates fairly well the spatial scale and the interannual and intraseasonal variability of the extreme events, although its extreme precipitation intensity is weaker than observed. In addition, both observations and the simulations show possible forcing of extreme events by African easterly waves. 3c. Other Contributions Through our collaborations, we have made contributions to a wide range of outcomes. For research focused on terrestrial behavior, these have included (1) upwind schemes for gas dynamics, (2) a nonlinear perspective on the dynamics of the Madden-Julian Oscillation, (3) numerical realism of thermal co

Gutowski, William J.; Prusa, Joseph M.; Smolarkiewicz, Piotr K.

2012-05-08T23:59:59.000Z

Note: This page contains sample records for the topic "regional dynamics model" 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

Designability, thermodynamic stability, and dynamics in protein folding: A lattice model study  

E-Print Network [OSTI]

Designability, thermodynamic stability, and dynamics in protein folding: A lattice model study Re October 1998 In the framework of a lattice-model study of protein folding, we investigate the interplay model. Lattice models have been widely used in the study of protein folding dynamics.2­8 The main

Levine, Alex J.

202

Comparative Studies of Clustering Techniques for Real-Time Dynamic Model Reduction  

E-Print Network [OSTI]

Dynamic model reduction in power systems is necessary for improving computational efficiency. Traditional model reduction using linearized models or offline analysis would not be adequate to capture power system dynamic behaviors, especially the new mix of intermittent generation and intelligent consumption makes the power system more dynamic and non-linear. Real-time dynamic model reduction emerges as an important need. This paper explores the use of clustering techniques to analyze real-time phasor measurements to determine generator groups and representative generators for dynamic model reduction. Two clustering techniques -- graph clustering and evolutionary clustering -- are studied in this paper. Various implementations of these techniques are compared and also compared with a previously developed Singular Value Decomposition (SVD)-based dynamic model reduction approach. Various methods exhibit different levels of accuracy when comparing the reduced model simulation against the original model. But some ...

Hogan, Emilie; Halappanavar, Mahantesh; Huang, Zhenyu; Lin, Guang; Lu, Shuai; Wang, Shaobu

2015-01-01T23:59:59.000Z

203

11.482J / 1.285J / ESD.193J Regional Socioeconomic Impact Analyses and Modeling, Fall 2003  

E-Print Network [OSTI]

Reviews regional economic theories and models and provides students with experience in using alternative economic impact assessment models on microcomputers. Problem sets are oriented around infrastructure, housing, energy, ...

Polenske, Karen R.

204

Radial electric field 3D modeling for wire arrays driving dynamic hohlraums on Z.  

SciTech Connect (OSTI)

The anode-cathode structure of the Z-machine wire array results in a higher negative radial electric field (Er) on the wires near the cathode relative to the anode. The magnitude of this field has been shown to anti-correlate with the axial radiation top/bottom symmetry in the DH (Dynamic Hohlraum). Using 3D modeling, the structure of this field is revealed for different wire-array configurations and for progressive mechanical alterations, providing insight for minimizing the negative Er on the wire array in the anode-to-cathode region of the DH. Also, the 3D model is compared to Sasorov's approximation, which describes Er at the surface of the wire in terms of wire-array parameters.

Mock, Raymond Cecil

2007-06-01T23:59:59.000Z

205

Hybrid thermal model for swimming pools based on artificial neural networks for southeast region of Brazil  

Science Journals Connector (OSTI)

Nowadays, the usage of systems based on solar energy have been largely stimulated. The correct designing and efficiency of these systems are highly dependent of the seasonal climatic characteristics of the regions where they will be installed. In this ... Keywords: Artificial neural networks, Hybrid models, Renewable energy, Solar energy systems, Thermal model of pool

Enock T. Santos; Luis E. ZáRate; Elizabeth M. D. Pereira

2013-06-01T23:59:59.000Z

206

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

207

Dynamic Cost-Loss Ratio Decision-making Model with an Autocorrelated Climate Variable  

Science Journals Connector (OSTI)

A dynamic decision-making problem is considered involving the use of information about the autocorrelation of a climate variable. Specifically, an infinite horizon, discounted version of the dynamic cost-loss ratio model is treated, in which only ...

Richard W. Katz

1993-01-01T23:59:59.000Z

208

Dynamic Model of Hydrogen in GaN  

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

Dynamic Model of Hydrogen in GaN by S. M. Myers and A. F. Wright Motivation-Hydrogen is incorporated into p-type GaN during MOCVD growth, producing highly stable passivation of the Mg acceptors. Complete acceptor activation by thermal H release requires temperatures that threaten material integrity, prompting compromises in device processing. At lower temperatures, forward bias of p-n junctions or electron-beam irradiation produces a metastable, reversible activation without H release. To understand and control such effects, we are developing a mathematical model of H behavior wherein state energies from density-functional theory are employed in diffusion-reaction equations. Previously, we used the greatly simplifying assumptions of local equilibrium among states

209

Abundance determinations in HII regions: model fitting versus Te-method  

E-Print Network [OSTI]

The discrepancy between the oxygen abundances in high-metallicity HII regions determined through the Te-method (and/or through the corresponding "strong lines - oxygen abundance" calibration) and that determined through the model fitting (and/or through the corresponding "strong lines - oxygen abundance" calibration) is discussed. It is suggested to use the interstellar oxygen abundance in the solar vicinity, derived with very high precision from the high-resolution observations of the weak interstellar absorption lines towards the stars, as a "Rosetta stone" to verify the validity of the oxygen abundances derived in HII regions with the Te-method at high abundances. The agreement between the value of the oxygen abundance at the solar galactocentric distance traced by the abundances derived in HII regions through the Te-method and that derived from the interstellar absorption lines towards the stars is strong evidence in favor of that i) the two-zone model for Te seems to be a realistic interpretation of the temperature structure within HII regions, and ii) the classic Te-method provides accurate oxygen abundances in HII regions. It has been concluded that the "strong lines - oxygen abundance" calibrations must be based on the HII regions with the oxygen abundances derived with the Te-method but not on the existing grids of the models for HII regions.

L. S. Pilyugin

2002-11-14T23:59:59.000Z

210

Quasi-dynamic model for an organic Rankine cycle  

Science Journals Connector (OSTI)

Abstract When considering solar based thermal energy input to an organic Rankine cycle (ORC), intermittent nature of the heat input does not only adversely affect the power output but also it may prevent ORC to operate under steady state conditions. In order to identify reliability and efficiency of such systems, this paper presents a simplified transient modeling approach for an ORC operating under variable heat input. The approach considers that response of the system to heat input variations is mainly dictated by the evaporator. Consequently, overall system is assembled using dynamic models for the heat exchangers (evaporator and condenser) and static models of the pump and the expander. In addition, pressure drop within heat exchangers is neglected. The model is compared to benchmark numerical and experimental data showing that the underlying assumptions are reasonable for cases where thermal input varies in time. Furthermore, the model is studied on another configuration and mass flow rates of both the working fluid and hot water and hot water’s inlet temperature to the ORC unit are shown to have direct influence on the system’s response.

Musbaudeen O. Bamgbopa; Eray Uzgoren

2013-01-01T23:59:59.000Z

211

Modeling-Computer Simulations At Nw Basin & Range Region (Blackwell, Et  

Open Energy Info (EERE)

source 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 History Facebook icon Twitter icon » Modeling-Computer Simulations At Nw Basin & Range Region (Blackwell, Et Al., 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Modeling-Computer Simulations At Nw Basin & Range Region (Blackwell, Et Al., 2003) Exploration Activity Details Location Northwest Basin and Range Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes Developed natural state mass and energy transport fluid flow models of generic Basin and Range systems based on Dixie Valley data that help to

212

A comparative study of Lotka-Volterra and system dynamics models for simulation of technology industry dynamics  

E-Print Network [OSTI]

Scholars have developed a range of qualitative and quantitative models for generalizing the dynamics of technological innovation and identifying patterns of competition between rivals. This thesis compares two predominant ...

Ünver, Hakk? Özgür

2008-01-01T23:59:59.000Z

213

Detonating Failed Deflagration Model of Thermonuclear Supernovae I. Explosion Dynamics  

E-Print Network [OSTI]

We present a detonating failed deflagration model of Type Ia supernovae. In this model, the thermonuclear explosion of a massive white dwarf follows an off-center deflagration. We conduct a survey of asymmetric ignition configurations initiated at various distances from the stellar center. In all cases studied, we find that only a small amount of stellar fuel is consumed during deflagration phase, no explosion is obtained, and the released energy is mostly wasted on expanding the progenitor. Products of the failed deflagration quickly reach the stellar surface, polluting and strongly disturbing it. These disturbances eventually evolve into small and isolated shock-dominated regions which are rich in fuel. We consider these regions as seeds capable of forming self-sustained detonations that, ultimately, result in the thermonuclear supernova explosion. Preliminary nucleosynthesis results indicate the model supernova ejecta are typically composed of about 0.1-0.25 Msun of silicon group elements, 0.9-1.2 Msun of iron group elements, and are essentially carbon-free. The ejecta have a composite morphology, are chemically stratified, and display a modest amount of intrinsic asymmetry. The innermost layers are slightly egg-shaped with the axis ratio ~1.2-1.3 and dominated by the products of silicon burning. This central region is surrounded by a shell of silicon-group elements. The outermost layers of ejecta are highly inhomogeneous and contain products of incomplete oxygen burning with only small admixture of unburned stellar material. The explosion energies are ~1.3-1.5 10^51 erg.

Tomasz Plewa

2006-11-24T23:59:59.000Z

214

Regional flood hydrology in a semi-arid catchment using a GLS regression model  

Science Journals Connector (OSTI)

Summary The regional flood frequency hydrology of the 86,000 km2 and semi-arid Ebro catchment is investigated using an extended generalised least square model that includes separate descriptions for sampling errors and model errors. The Ebro catchment is characterised by large hydro-climatic heterogeneities among sub-regions. However, differences in flood processes among sites are better explained by a set of new catchment descriptors introduced into hydrological regression models, such as new characteristics derived from the slope of flow duration curves, the ratio of mean annual precipitation to extreme precipitations and the aridity index. These additions enabled a more direct link to be established between the general flow regime and the extreme flood characteristics through-out the entire catchment. The new regression models developed in this study were compared to a set of existing models recommended for flood frequency estimation in Spain. It was found that the generalised least squares model developed in this study improves the existing ordinary least squares models both at regional and trans-regional scales. An adequate description of flood processes is obtained and, as a direct consequence, more reliable flood predictions in ungauged catchments are achieved.

Luis Mediero; Thomas R. Kjeldsen

2014-01-01T23:59:59.000Z

215

Toward a mechanistic modeling of nitrogen limitation on vegetation dynamics  

SciTech Connect (OSTI)

Nitrogen is a dominant regulator of vegetation dynamics, net primary production, and terrestrial carbon cycles; however, most ecosystem models use a rather simplistic relationship between leaf nitrogen content and photosynthetic capacity. Such an approach does not consider how patterns of nitrogen allocation may change with differences in light intensity, growing-season temperature and CO{sub 2} concentration. To account for this known variability in nitrogen-photosynthesis relationships, we develop a mechanistic nitrogen allocation model based on a trade-off of nitrogen allocated between growth and storage, and an optimization of nitrogen allocated among light capture, electron transport, carboxylation, and respiration. The developed model is able to predict the acclimation of photosynthetic capacity to changes in CO{sub 2} concentration, temperature, and radiation when evaluated against published data of V{sub c,max} (maximum carboxylation rate) and J{sub max} (maximum electron transport rate). A sensitivity analysis of the model for herbaceous plants, deciduous and evergreen trees implies that elevated CO{sub 2} concentrations lead to lower allocation of nitrogen to carboxylation but higher allocation to storage. Higher growing-season temperatures cause lower allocation of nitrogen to carboxylation, due to higher nitrogen requirements for light capture pigments and for storage. Lower levels of radiation have a much stronger effect on allocation of nitrogen to carboxylation for herbaceous plants than for trees, resulting from higher nitrogen requirements for light capture for herbaceous plants. As far as we know, this is the first model of complete nitrogen allocation that simultaneously considers nitrogen allocation to light capture, electron transport, carboxylation, respiration and storage, and the responses of each to altered environmental conditions. We expect this model could potentially improve our confidence in simulations of carbon-nitrogen interactions and the vegetation feedbacks to climate in Earth system models.

Xu, Chonggang [Los Alamos National Laboratory (LANL); Fisher, Rosie [National Center for Atmospheric Research (NCAR); Wullschleger, Stan D [ORNL; Wilson, Cathy [Los Alamos National Laboratory (LANL); Cai, Michael [Los Alamos National Laboratory (LANL); McDowell, Nathan [Los Alamos National Laboratory (LANL)

2012-01-01T23:59:59.000Z

216

Modeling Io's Sublimation-Driven Atmosphere: Gas Dynamics and Radiation Emission  

SciTech Connect (OSTI)

Io's sublimation-driven atmosphere is modeled using the direct simulation Monte Carlo method. These rarefied gas dynamics simulations improve upon earlier models by using a three-dimensional domain encompassing the entire planet computed in parallel. The effects of plasma impact heating, planetary rotation, and inhomogeneous surface frost are investigated. Circumplanetary flow is predicted to develop from the warm subsolar region toward the colder night-side. The non-equilibrium thermal structure of the atmosphere, including vibrational and rotational temperatures, is also presented. Io's rotation leads to an asymmetric surface temperature distribution which is found to strengthen circumplanetary flow near the dusk terminator. Plasma heating is found to significantly inflate the atmosphere on both day- and night-sides. The plasma energy flux also causes high temperatures at high altitudes but permits relatively cooler temperatures at low altitudes near the dense subsolar point due to plasma energy depletion. To validate the atmospheric model, a radiative transfer model was developed utilizing the backward Monte Carlo method. The model allows the calculation of the atmospheric radiation from emitting/absorbing and scattering gas using an arbitrary scattering law and an arbitrary surface reflectivity. The model calculates the spectra in the {nu}{sub 2} vibrational band of SO{sub 2} which are then compared to the observational data.

Walker, Andrew C.; Goldstein, David B.; Varghese, Philip L.; Trafton, Laurence M.; Moore, Chris H.; Stewart, Benedicte [University of Texas at Austin, Department of Aerospace Engineering, 210 East 24. Street W. R. Woolrich Laboratories 1 University Station, C0600 Austin, TX 78712 (United States); Gratiy, Sergey L.; Levin, Deborah A. [Pennsylvania State University, Department of Aerospace Engineering, 229 Hammond, University Park, PA 16802 (United States)

2008-12-31T23:59:59.000Z

217

Object-oriented modelling and simulation for the ALFRED dynamics  

Science Journals Connector (OSTI)

Abstract In this paper, a control-oriented modelling and simulation tool for the study of the Advanced Lead-cooled Fast Reactor European Demonstrator (ALFRED) plant dynamics is presented. It has been developed in order to perform design-basis transient analyses aimed at providing essential feedbacks for the system design finalization. The simulator has been meant to be modular, open and efficient. In this perspective, an object-oriented modelling approach has been adopted, by employing the reliable, tested and well-documented Modelica language. Simulation of core behaviour is based on point kinetics for neutronics and one-dimensional heat transfer models for thermal-hydraulics, coherently with ALFRED specifications. An effort has been spent to model the bayonet-tube Steam Generator (SG) foreseen to be installed within the reactor vessel. The primary loop model has been built by connecting the above-mentioned components (taking into account suitable time delays) and by incorporating the cold pool, which has revealed to be fundamental for an accurate definition of the time constants characteristic of the system because of its large thermal inertia. The description of the overall plant has been finalized by connecting standard turbine, condenser and other components of the balance of plant. Afterwards, the reactor responses to three typical transient initiators have been simulated (i.e., reduction of feedwater mass flow rate, variation of the turbine admission valve coefficient and transient of overpower). Simulation outcomes confirm the strong coupling between core and SG, besides showing the characteristic time constants of the various component responses. Results of the present study constitute a starting point in the definition of plant control strategies, laying the basis for investigation and development of a model-based control-system design.

Roberto Ponciroli; Andrea Bigoni; Antonio Cammi; Stefano Lorenzi; Lelio Luzzi

2014-01-01T23:59:59.000Z

218

Short communication Dynamics of a model of two delay-coupled relaxation oscillators  

E-Print Network [OSTI]

: Coupled oscillators Devil's Staircase Delay-differential equations a b s t r a c t This paper investigates by regions of complicated dynamics, reminiscent of the Devil's Staircase. Stability of motions in the in

Rand, Richard H.

219

Modeling-Computer Simulations At Northern Basin & Range Region (Blackwell,  

Open Energy Info (EERE)

Northern Basin & Northern Basin & Range Region (Blackwell, Et Al., 2003) Exploration Activity Details Location Northern Basin and Range Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness useful DOE-funding Unknown Notes Developed natural state mass and energy transport fluid flow models of generic Basin and Range systems based on Dixie Valley data that help to understand the nature of large scale constraints on the location and characteristics of the geothermal systems References D. D. Blackwell, K. W. Wisian, M. C. Richards, Mark Leidig, Richard Smith, Jason McKenna (2003) Geothermal Resource Analysis And Structure Of Basin And Range Systems, Especially Dixie Valley Geothermal Field, Nevada Retrieved from "http://en.openei.org/w/index.php?title=Modeling-Computer_Simulations_At_Northern_Basin_%26_Range_Region_(Blackwell,_Et_Al.,_2003)&oldid=401422

220

A Numerical Model for the Dynamic Simulation of a Recirculation Single-Effect Absorption Chiller  

E-Print Network [OSTI]

A Numerical Model for the Dynamic Simulation of a Recirculation Single- Effect Absorption Chiller A dynamic model for the simulation of a new single-effect water/lithium bromide absorption chiller. Keywords: absorption; chiller; modelling; transient; water-lithium bromide; falling film hal-00713904

Paris-Sud XI, Université de

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221

Dynamic Friction Models for Longitudinal Road/Tire Interaction: Theoretical Advances  

E-Print Network [OSTI]

Dynamic Friction Models for Longitudinal Road/Tire Interaction: Theoretical Advances C. Canudas we derive a new dynamic friction force model for the longitudinal road/tire interaction for wheeled-point friction problems, called the LuGre model [1]. By assuming a con- tact patch between the tire

Tsiotras, Panagiotis

222

Lateral Dynamics Reconstruction for Sharp'71 Motorcycle Model with P2I Observer  

E-Print Network [OSTI]

Lateral Dynamics Reconstruction for Sharp'71 Motorcycle Model with P2I Observer Chabane Chenane (motorcycle, scooter, etc.). For that purpose, the well-known motorcycle model developed by Sharp in 1971 is used. This model characterizes the lateral dynamics of a motorcycle [16]. The roll angle

Paris-Sud XI, Université de

223

Transforming the representation of the boundary layer and low clouds for high-resolution regional climate modeling: Final report  

SciTech Connect (OSTI)

Stratocumulus and shallow cumulus clouds in subtropical oceanic regions (e.g., Southeast Pacific) cover thousands of square kilometers and play a key role in regulating global climate (e.g., Klein and Hartmann, 1993). Numerical modeling is an essential tool to study these clouds in regional and global systems, but the current generation of climate and weather models has difficulties in representing them in a realistic way (e.g., Siebesma et al., 2004; Stevens et al., 2007; Teixeira et al., 2011). While numerical models resolve the large-scale flow, subgrid-scale parameterizations are needed to estimate small-scale properties (e.g. boundary layer turbulence and convection, clouds, radiation), which have significant influence on the resolved scale due to the complex nonlinear nature of the atmosphere. To represent the contribution of these fine-scale processes to the resolved scale, climate models use various parameterizations, which are the main pieces in the model that contribute to the low clouds dynamics and therefore are the major sources of errors or approximations in their representation. In this project, we aim to 1) improve our understanding of the physical processes in thermal circulation and cloud formation, 2) examine the performance and sensitivity of various parameterizations in the regional weather model (Weather Research and Forecasting model; WRF), and 3) develop, implement, and evaluate the advanced boundary layer parameterization in the regional model to better represent stratocumulus, shallow cumulus, and their transition. Thus, this project includes three major corresponding studies. We find that the mean diurnal cycle is sensitive to model domain in ways that reveal the existence of different contributions originating from the Southeast Pacific land-masses. The experiments suggest that diurnal variations in circulations and thermal structures over this region are influenced by convection over the Peruvian sector of the Andes cordillera, while the mostly dry mountain-breeze circulations force an additional component that results in semi-diurnal variations near the coast. A series of numerical tests, however, reveal sensitivity of the simulations to the choice of vertical grid, limiting the possibility of solid quantitative statements on the amplitudes and phases of the diurnal and semidiurnal components across the domain. According to our experiments, the Mellor-Yamada-Nakanishi-Niino (MYNN) boundary layer scheme and the WSM6 microphysics scheme is the combination of schemes that performs best. For that combination, mean cloud cover, liquid water path, and cloud depth are fairly wellsimulated, while mean cloud top height remains too low in comparison to observations. Both microphysics and boundary layer schemes contribute to the spread in liquid water path and cloud depth, although the microphysics contribution is slightly more prominent. Boundary layer schemes are the primary contributors to cloud top height, degree of adiabaticity, and cloud cover. Cloud top height is closely related to surface fluxes and boundary layer structure. Thus, our study infers that an appropriate tuning of cloud top height would likely improve the low-cloud representation in the model. Finally, we show that entrainment governs the degree of adiabaticity, while boundary layer decoupling is a control on cloud cover. In the intercomparison study using WRF single-column model experiments, most parameterizations show a poor agreement of the vertical boundary layer structure when compared with large-eddy simulation models. We also implement a new Total-Energy/Mass- Flux boundary layer scheme into the WRF model and evaluate its ability to simulate both stratocumulus and shallow cumulus clouds. Result comparisons against large-eddy simulation show that this advanced parameterization based on the new Eddy-Diffusivity/Mass-Flux approach provides a better performance than other boundary layer parameterizations.

Huang, Hsin-Yuan; Hall, Alex

2013-07-24T23:59:59.000Z

224

The Dynamics of Deterministic Chaos in Numerical Weather Prediction Models  

E-Print Network [OSTI]

Atmospheric weather systems are coherent structures consisting of discrete cloud cells forming patterns of rows/streets, mesoscale clusters and spiral bands which maintain their identity for the duration of their appreciable life times in the turbulent shear flow of the planetary Atmospheric Boundary Layer. The existence of coherent structures (seemingly systematic motion) in turbulent flows has been well established during the last 20 years of research in turbulence. Numerical weather prediction models based on the inherently non-linear Navier-Stokes equations do not give realistic forecasts because of the following inherent limitations: (1) the non-linear governing equations for atmospheric flows do not have exact analytic solutions and being sensitive to initial conditions give chaotic solutions characteristic of deterministic chaos (2) the governing equations do not incorporate the dynamical interactions and co-existence of the complete spectrum of turbulent fluctuations which form an integral part of the large coherent weather systems (3) limitations of available computer capacity necessitates severe truncation of the governing equations, thereby generating errors of approximations (4) the computer precision related roundoff errors magnify the earlier mentioned uncertainties exponentially with time and the model predictions become unrealistic. The accurate modelling of weather phenomena therefore requires alternative concepts and computational techniques. In this paper a universal theory of deterministic chaos applicable to the formation of coherent weather structures in the ABL is presented.

A. Mary Selvam

2003-10-07T23:59:59.000Z

225

Emerging disease dynamics in a model coupling within-host and ...  

E-Print Network [OSTI]

Aug 2, 2014 ... Immunological models consider the within-host dynamics independent of the interactions between hosts (e.g., De Leenheer and Smith, 2003;.

Xiuli Cen

2014-08-27T23:59:59.000Z

226

Estimation of Parameterized Spatio-Temporal Dynamic Models Ke Xu and Christopher K. Wikle  

E-Print Network [OSTI]

Estimation of Parameterized Spatio-Temporal Dynamic Models Ke Xu and Christopher K. Wikle: Christopher K. Wikle, Department of Statistics, University of Missouri, 146 Math Science Building, Columbia

227

Dynamic Modeling of Cell Migration and Spreading Behaviors on Fibronectin Coated Planar Substrates and Micropatterned Geometries  

E-Print Network [OSTI]

An integrative cell migration model incorporating focal adhesion (FA) dynamics, cytoskeleton and nucleus remodeling, actin motor activity, and lamellipodia protrusion is developed for predicting cell spreading and migration ...

Kim, Min-Cheol

228

Creating dynamic equivalent PV circuit models with impedance spectroscopy for arc-fault modeling.  

SciTech Connect (OSTI)

Article 690.11 in the 2011 National Electrical Code{reg_sign} (NEC{reg_sign}) requires new photovoltaic (PV) systems on or penetrating a building to include a listed arc fault protection device. Currently there is little experimental or empirical research into the behavior of the arcing frequencies through PV components despite the potential for modules and other PV components to filter or attenuate arcing signatures that could render the arc detector ineffective. To model AC arcing signal propagation along PV strings, the well-studied DC diode models were found to inadequately capture the behavior of high frequency arcing signals. Instead dynamic equivalent circuit models of PV modules were required to describe the impedance for alternating currents in modules. The nonlinearities present in PV cells resulting from irradiance, temperature, frequency, and bias voltage variations make modeling these systems challenging. Linearized dynamic equivalent circuits were created for multiple PV module manufacturers and module technologies. The equivalent resistances and capacitances for the modules were determined using impedance spectroscopy with no bias voltage and no irradiance. The equivalent circuit model was employed to evaluate modules having irradiance conditions that could not be measured directly with the instrumentation. Although there was a wide range of circuit component values, the complex impedance model does not predict filtering of arc fault frequencies in PV strings for any irradiance level. Experimental results with no irradiance agree with the model and show nearly no attenuation for 1 Hz to 100 kHz input frequencies.

Johnson, Jay Dean; Kuszmaul, Scott S.; Strauch, Jason E.; Schoenwald, David Alan

2011-06-01T23:59:59.000Z

229

High-resolution observations of active region moss and its dynamics  

E-Print Network [OSTI]

The \\textit{High resolution Coronal Imager (Hi-C)} has provided the sharpest view of the EUV corona to date. In this paper we exploit its impressive resolving power to provide the first analysis of the fine-scale structure of moss in an active region. The data reveal that the moss is made up of a collection of fine threads, that have widths with a mean and standard deviation of $440\\pm190$~km (Full Width Half Maximum). {The brightest moss emission is located at the visible head of the fine-scale structure and the fine structure appears to extend into the lower solar atmosphere.} The emission decreases along the features implying the lower sections are most likely dominated by cooler transition region plasma. These threads appear to be the cool, lower legs of the hot loops. In addition, the increased resolution allows for the first direct observation {of physical displacements of the moss fine-structure in a direction transverse to its central axis. Some of these transverse displacements demonstrate periodic b...

Morton, R J

2014-01-01T23:59:59.000Z

230

Modeling the Dispersal of an Active Region: Quantifying Energy Input into the Corona  

Science Journals Connector (OSTI)

In this paper, a new technique for modeling nonlinear force-free fields directly from line-of-sight magnetogram observations is presented. The technique uses sequences of magnetograms directly as lower boundary conditions to drive the evolution of coronal magnetic fields between successive force-free equilibria over long periods of time. It is illustrated by applying it to SOHO: MDI observations of a decaying active region, NOAA AR 8005. The active region is modeled during a four-day period around its central meridian passage. Over this time, the dispersal of the active region is dominated by random motions due to small-scale convective cells. Through studying the buildup of magnetic energy in the model, it is found that such small-scale motions may inject anywhere from (2.5-3) ? 1025 erg s–1 of free magnetic energy into the coronal field. Most of this energy is stored within the center of the active region in the low corona, below 30 Mm. After four days, the buildup of free energy is 10% that of the corresponding potential field. This energy buildup is sufficient to explain the radiative losses at coronal temperatures within the active region. Small-scale convective motions therefore play an integral part in the energy balance of the corona. This new technique has wide ranging applications with the new high-resolution, high-cadence observations from the SDO:HMI and SDO:AIA instruments.

Duncan H. Mackay; L. M. Green; Aad van Ballegooijen

2011-01-01T23:59:59.000Z

231

Hybrid thermal model for swimming pools based on artificial neural networks for southeast region of Brazil  

Science Journals Connector (OSTI)

Nowadays, the usage of systems based on solar energy have been largely stimulated. The correct designing and efficiency of these systems are highly dependent of the seasonal climatic characteristics of the regions where they will be installed. In this work, we propose a hybrid structure to simulate the thermodynamic behavior of pools, which uses neural computational models to incorporate the climatic information of the regions being analyzed. The neural models have as input variables data of geographic position such as: elevation, latitude and longitude, what permits to delineate the climatic profile of the region being considered. The human activity is another factor that directly influences the thermodynamic behavior of pools and, therefore, is also considered. In this work, changes of volume are estimated in order to track losses due to the human activity.

Enock T. Santos; Luis E. Zárate; Elizabeth M.D. Pereira

2013-01-01T23:59:59.000Z

232

Evaluation Model for Safety Capacity of Chemical Industrial Park Based on Acceptable Regional Risk  

Science Journals Connector (OSTI)

Abstract The paper defines the Safety Capacity of Chemical Industrial Park (SCCIP) from the perspective of acceptable regional risk. For the purpose to explore the evaluation model for the SCCIP, a method based on quantitative risk assessment was adopted for evaluating transport risk and to confirm reasonable safety transport capacity for chemical industrial park, and then by combining with the safety storage capacity,a SCCIP evaluation model was put forward. The SCCIP was decided by the smaller one between the largest safety storage capacity and the maximum safety transport capacity, or else, the regional risk of the park will exceed the acceptable level. The developed method was applied to a chemical industrial park in Guangdong province to obtain the maximum safety transport capacity and the SCCIP. The results can be realized the regional risk control to the Park effectively.

Guohua Chen; Shukun Wang; Xiaoqun Tan

2014-01-01T23:59:59.000Z

233

Specification of fields quality in the interaction region magnets of the high luminosity LHC based on dynamic aperture  

E-Print Network [OSTI]

New large aperture Inner Triplet quadrupoles, separation dipoles and the nearby matching quadrupoles will be installed in the low-beta interaction regions (IR) of the high luminosity LHC upgrade (HL-LHC) [1]. The large aperture is necessary for accommodating the increased beam size due to much higher beta functions in these magnets for the low collision optics. The high beta functionswill amplify the effects of field errors in the new magnets leading to a smaller dynamic aperture (DA). It is, therefore, critical to evaluate the impact of these errors on the DA and specify the magnet field quality (FQ) satisfying an acceptable DA while being realistically achievable. The study is performed for the HL-LHC lattice layouts SLHCV3.1b and HLLHCV1.0 for collision and injection energies.

Nosochkov, Y; Wang, M H; Fartoukh, S; Giovannozzi, M; De Maria, R; McIntosh, E

2014-01-01T23:59:59.000Z

234

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

235

A MODIFIED GAMBLER'S RUIN MODEL POLYETHYLENE CHAINS IN THE AMORPHOUS REGION  

E-Print Network [OSTI]

A MODIFIED GAMBLER'S RUIN MODEL OF POLYETHYLENE CHAINS IN THE AMORPHOUS REGION Zhong­Hui Duan and Louis N. Howard Department of Mathematics The Florida State University ABSTRACT. Polyethylene chainsM 3 +O(M 2 ). INTRODUCTION Semicrystalline polyethylene formed from melt generally consists

Aluffi, Paolo

236

Regional Characterization of Freshwater Use in LCA: Modeling Direct Impacts on Human Health  

Science Journals Connector (OSTI)

Regional Characterization of Freshwater Use in LCA: Modeling Direct Impacts on Human Health ... Life cycle assessment (LCA) is a methodology that quantifies potential environmental impacts for comparative purposes in a decision-making context. ... While potential environmental impacts from pollutant emissions into water are characterized in LCA, impacts from water unavailability are not yet fully quantified. ...

Anne-Marie Boulay; Cécile Bulle; Jean-Baptiste Bayart; Louise Deschênes; Manuele Margni

2011-09-09T23:59:59.000Z

237

Optimized regional and interannual variability of lightning in a global chemical transport model constrained  

E-Print Network [OSTI]

to remove their diurnal sampling bias, we construct a monthly time series of lightning flash rates for 1998, D20307, doi:10.1029/2012JD017934. 1. Introduction [2] The extreme heat in a lightning flash channelOptimized regional and interannual variability of lightning in a global chemical transport model

Jacob, Daniel J.

238

Overview of Avista GHG Modeling NPCC Greenhouse Gas and the Regional Power System Conference  

E-Print Network [OSTI]

6/5/2013 1 Overview of Avista GHG Modeling NPCC Greenhouse Gas and the Regional Power System Pricing $70 $80 Weighted Average Expected Case 2020 Hi h GHG P i i C $20 $30 $40 $50 $60 dollarspermetricton 2020 High GHG Pricing Case 2020 Low GHG Pricing Case 2025 High GHG Pricing Case 2025 Low GHG

239

Resampling of regional climate model output for the simulation of extreme river flows  

E-Print Network [OSTI]

for the simulation of extreme river flows. This is important to assess the impact of climate change on river flooding biases in the RCM data, the simulated extreme flood quantiles correspond quite well with those obtainedResampling of regional climate model output for the simulation of extreme river flows Robert

Haak, Hein

240

High-Speed extraction model of interest region in the parcel image of large size  

Science Journals Connector (OSTI)

This paper deals with a model for the high-speed extraction of ROI (Region Of Interest) during the process of logistics transported on conveyor belt. The objective of this paper is to extract various ROIs from large size image of logistics more than ...

Moon-sung Park; Il-sook Kim; Eun-kyung Cho; Young-hee Kwon; Jong-heung Park

2005-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "regional dynamics model" 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

Influence of spatial resolution on regional climate model derived wind climates  

E-Print Network [OSTI]

of northern Europe is more profound in the wind extremes than in the central tendency. The domain are of similar magnitude to the climate change signal in extreme wind events derived in prior research and mayInfluence of spatial resolution on regional climate model derived wind climates S. C. Pryor,1 G

Pryor, Sara C.

242

Simulation of systems with dynamically varying model structure  

Science Journals Connector (OSTI)

Hybrid systems are dynamical systems composed of components with discrete and continuous behavior. Some systems change their structure during simulation, or their components behavior is essentially changing. This ''structural dynamics'' can be described ... Keywords: Discrete-continuous simulation, Hybrid systems, Modelica, Structural dynamics, VHDL-AMS

Peter Schwarz

2008-12-01T23:59:59.000Z

243

Pion photoproduction in a dynamical coupled-channels model  

E-Print Network [OSTI]

The charged and neutral pion photoproduction reactions are investigated in a dynamical coupled-channels approach based on the formulation of Haberzettl, Huang, and Nakayama [Phys. Rev. C 83, 065502 (2011)]. The hadronic final-state interaction is provided by the Juelich pi-N model, which includes the channels pi-N and eta-N comprising stable hadrons as well as the effective pi-pi-N channels pi-Delta, sigma-N, and rho-N. This hadronic model has been quite successful in describing pi-N to pi-N scattering for center-of-mass energies up to 1.9 GeV. By construction, the full pion photoproduction current satisfies the generalized Ward-Takahashi identity and thus is gauge invariant as a matter of course. The calculated differential cross sections and photon spin asymmetries up to 1.65 GeV center-of-mass energy for the reactions gamma p to pi+ n, gamma p to pi0 p, gamma n to pi- p and gamma n to pi0 n are in good agreement with the experimental data.

Huang, F; Haberzettl, H; Haidenbauer, J; Hanhart, C; Krewald, S; ner, U -G Meiß; Nakayama, K

2011-01-01T23:59:59.000Z

244

Pion photoproduction in a dynamical coupled-channels model  

E-Print Network [OSTI]

The charged and neutral pion photoproduction reactions are investigated in a dynamical coupled-channels approach based on the formulation of Haberzettl, Huang, and Nakayama [Phys. Rev. C 83, 065502 (2011)]. The hadronic final-state interaction is provided by the Juelich pi-N model, which includes the channels pi-N and eta-N comprising stable hadrons as well as the effective pi-pi-N channels pi-Delta, sigma-N, and rho-N. This hadronic model has been quite successful in describing pi-N to pi-N scattering for center-of-mass energies up to 1.9 GeV. By construction, the full pion photoproduction current satisfies the generalized Ward-Takahashi identity and thus is gauge invariant as a matter of course. The calculated differential cross sections and photon spin asymmetries up to 1.65 GeV center-of-mass energy for the reactions gamma p to pi+ n, gamma p to pi0 p, gamma n to pi- p and gamma n to pi0 n are in good agreement with the experimental data.

F. Huang; M. Döring; H. Haberzettl; J. Haidenbauer; C. Hanhart; S. Krewald; U. -G. Meiß ner; K. Nakayama

2011-10-17T23:59:59.000Z

245

Ultrafast Structural Dynamics in Combustion Relevant Model Systems  

SciTech Connect (OSTI)

The research project explored the time resolved structural dynamics of important model reaction system using an array of novel methods that were developed specifically for this purpose. They include time resolved electron diffraction, time resolved relativistic electron diffraction, and time resolved Rydberg fingerprint spectroscopy. Toward the end of the funding period, we also developed time-resolved x-ray diffraction, which uses ultrafast x-ray pulses at LCLS. Those experiments are just now blossoming, as the funding period expired. In the following, the time resolved Rydberg Fingerprint Spectroscopy is discussed in some detail, as it has been a very productive method. The binding energy of an electron in a Rydberg state, that is, the energy difference between the Rydberg level and the ground state of the molecular ion, has been found to be a uniquely powerful tool to characterize the molecular structure. To rationalize the structure sensitivity we invoke a picture from electron diffraction: when it passes the molecular ion core, the Rydberg electron experiences a phase shift compared to an electron in a hydrogen atom. This phase shift requires an adjustment of the binding energy of the electron, which is measurable. As in electron diffraction, the phase shift depends on the molecular, geometrical structure, so that a measurement of the electron binding energy can be interpreted as a measurement of the molecule’s structure. Building on this insight, we have developed a structurally sensitive spectroscopy: the molecule is first elevated to the Rydberg state, and the binding energy is then measured using photoelectron spectroscopy. The molecule’s structure is read out as the binding energy spectrum. Since the photoionization can be done with ultrafast laser pulses, the technique is inherently capable of a time resolution in the femtosecond regime. For the purpose of identifying the structures of molecules during chemical reactions, and for the analysis of molecular species in the hot environments of combustion processes, there are several features that make the Rydberg ionization spectroscopy uniquely useful. First, the Rydberg electron’s orbit is quite large and covers the entire molecule for most molecular structures of combustion interest. Secondly, the ionization does not change vibrational quantum numbers, so that even complicated and large molecules can be observed with fairly well resolved spectra. In fact, the spectroscopy is blind to vibrational excitation of the molecule. This has the interesting consequence for the study of chemical dynamics, where the molecules are invariably very energetic, that the molecular structures are observed unobstructed by the vibrational congestion that dominates other spectroscopies. This implies also that, as a tool to probe the time-dependent structural dynamics of chemically interesting molecules, Rydberg spectroscopy may well be better suited than electron or x-ray diffraction. With recent progress in calculating Rydberg binding energy spectra, we are approaching the point where the method can be evolved into a structure determination method. To implement the Rydberg ionization spectroscopy we use a molecular beam based, time-resolved pump-probe multi-photon ionization/photoelectron scheme in which a first laser pulse excites the molecule to a Rydberg state, and a probe pulse ionizes the molecule. A time-of-flight detector measures the kinetic energy spectrum of the photoelectrons. The photoelectron spectrum directly provides the binding energy of the electron, and thereby reveals the molecule’s time-dependent structural fingerprint. Only the duration of the laser pulses limits the time resolution. With a new laser system, we have now reached time resolutions better than 100 fs, although very deep UV wavelengths (down to 190 nm) have slightly longer instrument functions. The structural dynamics of molecules in Rydberg-excited states is obtained by delaying the probe ionization photon from the pump photon; the structural dynamics of molecules in their ground state or e

Weber, Peter M. [Brown University

2014-03-31T23:59:59.000Z

246

Networking technology adoption : system dynamics modeling of fiber-to-the-home  

E-Print Network [OSTI]

A system dynamics model is developed and run to study the adoption of fiber-to-the-home as a residential broadband technology. Communities that currently do not have broadband in the United States are modeled. This case ...

Kelic, Andjelka, 1972-

2005-01-01T23:59:59.000Z

247

A comparison of Bayesian versus deterministic formulation for dynamic data integration into reservoir models  

E-Print Network [OSTI]

Into Reservoir Models. (Decmnber 200 I) Danny LL Rojas Paico, B. S. , Universidad Nacional de Ingenieria, Peru Chair of Advisory Committee: Dr. Akhil Datta-Gupta The integration of dynamic data into reservoir models is known as automatic history matching...

Rojas Paico, Danny H.

2001-01-01T23:59:59.000Z

248

Evolutionary Processes in Economics: Multi-agent Model of Macrogenerations Dynamics  

E-Print Network [OSTI]

Evolutionary Processes in Economics: Multi-agent Model of Macrogenerations Dynamics Kateryna macroeconomic growth as an evolutionary process. Keywords. Economic growth, evolutionary theory, multi]. Our study models the economic growth as an evolutionary process, where the term `macrogeneration

López-Sánchez, Maite

249

A Blended Soundproof-to-Compressible Numerical Model for Small- to Mesoscale Atmospheric Dynamics  

Science Journals Connector (OSTI)

A blended model for atmospheric flow simulations is introduced that enables seamless transition from fully compressible to pseudo-incompressible dynamics. The model equations are written in nonperturbation form and integrated using a well-balanced ...

Tommaso Benacchio; Warren P. O’Neill; Rupert Klein

2014-12-01T23:59:59.000Z

250

Wetland model in an earth systems modeling framework for regional environmental policy analysis  

E-Print Network [OSTI]

The objective of this research is to investigate incorporating a wetland component into a land energy and water fluxes model, the Community Land Model (CLM). CLM is the land fluxes component of the Integrated Global Systems ...

Awadalla, Sirein Salah

2011-01-01T23:59:59.000Z

251

NREL: Regional Energy Deployment System (ReEDS) Model - Unique Value of  

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

Unique Value of ReEDS Unique Value of ReEDS Spatial Resolution and Variability Consideration The Regional Energy Deployment System (ReEDS) model has singular capabilities that differentiate it from other models and that make it uniquely suitable for certain types of analyses. While ReEDS can model all types of power generators and fuels-coal, gas, nuclear, renewables-it was designed primarily to address considerations for integrating renewable electric technologies into the power grid. In particular, it was designed to address the variable resource issues associated with solar and wind power as well as the remote nature of many of the best wind resources and their need for transmission. These capabilities require the two primary structural elements of ReEDS-a multiplicity of regions and a

252

Conceptual model for regional radionuclide transport from a salt dome repository: a technical memorandum  

SciTech Connect (OSTI)

Disposal of high-level radioactive wastes is a major environmental problem influencing further development of nuclear energy in this country. Salt domes in the Gulf Coast Basin are being investigated as repository sites. A major concern is geologic and hydrologic stability of candidate domes and potential transport of radionuclides by groundwater to the biosphere prior to their degradation to harmless levels of activity. This report conceptualizes a regional geohydrologic model for transport of radionuclides from a salt dome repository. The model considers transport pathways and the physical and chemical changes that would occur through time prior to the radionuclides reaching the biosphere. Necessary, but unknown inputs to the regional model involve entry and movement of fluids through the repository dome and across the dome-country rock interface and the effect on the dome and surrounding strata of heat generated by the radioactive wastes.

Kier, R.S.; Showalter, P.A.; Dettinger, M.D.

1980-05-30T23:59:59.000Z

253

Modeling-Computer Simulations At Walker-Lane Transitional Zone Region  

Open Energy Info (EERE)

Modeling-Computer Simulations At Walker-Lane Modeling-Computer Simulations At Walker-Lane Transitional Zone Region (Laney, 2005) Exploration Activity Details Location Walker-Lane Transition Zone Geothermal Region Exploration Technique Modeling-Computer Simulations Activity Date Usefulness not indicated DOE-funding Unknown Notes Assembling Crustal Geophysical Data for Geothermal Exploration in the Great Basin, Louie and Coolbaugh. We have compiled velocity information from sources in the literature, results of previous seismic experiments and earthquake-monitoring projects, and data donated from mining, geothermal, and petroleum companies. We also collected (May 2002 and August 2004) two new crustal refraction profiles across western Nevada and the northern and central Sierra. These sections had not been well characterized previously.

254

Borders as membranes :metaphors and models for improved policy in border regions.  

SciTech Connect (OSTI)

Political borders are controversial and contested spaces. In an attempt to better understand movement along and through political borders, this project applied the metaphor of a membrane to look at how people, ideas, and things ''move'' through a border. More specifically, the research team employed this metaphor in a system dynamics framework to construct a computer model to assess legal and illegal migration on the US-Mexico border. Employing a metaphor can be helpful, as it was in this project, to gain different perspectives on a complex system. In addition to the metaphor, the multidisciplinary team utilized an array of methods to gather data including traditional literature searches, an experts workshop, a focus group, interviews, and culling expertise from the individuals on the research team. Results from the qualitative efforts revealed strong social as well as economic drivers that motivate individuals to cross the border legally. Based on the information gathered, the team concluded that legal migration dynamics were of a scope we did not want to consider hence, available demographic models sufficiently capture migration at the local level. Results from both the quantitative and qualitative data searches were used to modify a 1977 border model to demonstrate the dynamic nature of illegal migration. Model runs reveal that current US-policies based on neo-classic economic theory have proven ineffective in curbing illegal migration, and that proposed enforcement policies are also likely to be ineffective. We suggest, based on model results, that improvement in economic conditions within Mexico may have the biggest impact on illegal migration to the U.S. The modeling also supports the views expressed in the current literature suggesting that demographic and economic changes within Mexico are likely to slow illegal migration by 2060 with no special interventions made by either government.

Malczynski, Leonard A.; Passell, Howard David; Forster, Craig B. (University of Utah, Salt Lake City, UT); Cockerill, Kristan (Cockerill Consulting, Boone, NC)

2005-10-01T23:59:59.000Z

255

STOCHASTIC COMPUTATIONAL DYNAMICAL MODEL OF UNCERTAIN STRUCTURE COUPLED WITH AN INSULATION LAYER  

E-Print Network [OSTI]

STOCHASTIC COMPUTATIONAL DYNAMICAL MODEL OF UNCERTAIN STRUCTURE COUPLED WITH AN INSULATION LAYER the effect of insulation layers in complex dynamical systems for low- and medium-frequency ranges such as car booming noise analysis, one introduces a sim- plified stochastic model of insulation layers based

Boyer, Edmond

256

A stochastic agent-based model of pathogen propagation in dynamic multi-relational social networks  

Science Journals Connector (OSTI)

We describe a general framework for modeling and stochastic simulation of epidemics in realistic dynamic social networks, which incorporates heterogeneity in the types of individuals, types of interconnecting risk-bearing relationships, and types of ... Keywords: Agent-based systems, Social Factors for HIV Risk, modeling and simulation environments, network-based simulation, risk network, system dynamics

Bilal Khan, Kirk Dombrowski, Mohamed Saad

2014-04-01T23:59:59.000Z

257

A DYNAMICAL MODEL OF TERRORISM FIRDAUS UDWADIA, GEORGE LEITMANN, AND LUCA LAMBERTINI  

E-Print Network [OSTI]

A DYNAMICAL MODEL OF TERRORISM FIRDAUS UDWADIA, GEORGE LEITMANN, AND LUCA LAMBERTINI Received 25 April 2006; Accepted 10 May 2006 This paper develops a dynamical model of terrorism. We consider the susceptibles to become pacifists. The paper proposes a new paradigm for studying terrorism, and looks

Udwadia, Firdaus E.

258

The living cell as a multi-agent organisation: a compositional organisation model of intracellular dynamics  

Science Journals Connector (OSTI)

Within the areas of Computational Organisation Theory and Artificial Intelligence, techniques have been developed to simulate and analyse dynamics within organisations in society. Usually these modelling techniques are applied to factories and to the ... Keywords: dynamics, intracellular, modular control analysis, organisational modeling, regulation and control

C. M. Jonker; J. L. Snoep; J. Treur; H. V. Westerhoff; W. C. A. Wijngaards

2010-01-01T23:59:59.000Z

259

Dynamic Friction Models for Longitudinal Road/Tire Interaction: Experimental Results  

E-Print Network [OSTI]

Dynamic Friction Models for Longitudinal Road/Tire Interaction: Experimental Results C. Canudas dynamic friction force model for the longitudinal road/tire interaction for wheeled ground vehicles is val- idated via experiments with an actual passenger vehicle. Contrary to common static friction/slip maps

Tsiotras, Panagiotis

260

Development of a Dynamic Model of a Small High-Speed Autonomous Underwater Vehicle  

E-Print Network [OSTI]

Development of a Dynamic Model of a Small High-Speed Autonomous Underwater Vehicle Haider N. Arafat-- A dynamic model is developed for a small, high- speed autonomous underwater vehicle. The vehicle has manner: 1) Wind angle and angle : From u = V cos , v = V sin sin , and w = V sin cos , we have tan

Virginia Tech

Note: This page contains sample records for the topic "regional dynamics model" 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

Filtering Noisy ECG Signals Using the Extended Kalman Filter Based on a Modified Dynamic ECG Model  

E-Print Network [OSTI]

Filtering Noisy ECG Signals Using the Extended Kalman Filter Based on a Modified Dynamic ECG Model for the filtering of noisy ECG signals. The method is based on a modified nonlinear dynamic model, previously introduced for the generation of synthetic ECG signals. An automatic parameter selection method has also been

Paris-Sud XI, Université de

262

ECG Denoising Using a Dynamical Model and a Marginalized Particle Filter  

E-Print Network [OSTI]

ECG Denoising Using a Dynamical Model and a Marginalized Particle Filter Chao Lin1,3, M of robust ECG denoising tech- niques is important for automatic diagnoses of cardiac diseases. Based on a previously suggested nonlinear dynamic model for the generation of realistic synthetic ECG, we introduce

Tourneret, Jean-Yves

263

Identification and modification of dynamical regions in proteins for alteration of enzyme catalytic effect  

DOE Patents [OSTI]

A method for analysis, control, and manipulation for improvement of the chemical reaction rate of a protein-mediated reaction is provided. Enzymes, which typically comprise protein molecules, are very efficient catalysts that enhance chemical reaction rates by many orders of magnitude. Enzymes are widely used for a number of functions in chemical, biochemical, pharmaceutical, and other purposes. The method identifies key protein vibration modes that control the chemical reaction rate of the protein-mediated reaction, providing identification of the factors that enable the enzymes to achieve the high rate of reaction enhancement. By controlling these factors, the function of enzymes may be modulated, i.e., the activity can either be increased for faster enzyme reaction or it can be decreased when a slower enzyme is desired. This method provides an inexpensive and efficient solution by utilizing computer simulations, in combination with available experimental data, to build suitable models and investigate the enzyme activity.

Agarwal, Pratul K.

2013-04-09T23:59:59.000Z

264

Coupled thermodynamic-dynamic semi-analytical model of Free Piston Stirling engines  

E-Print Network [OSTI]

The study of free piston Stirling engine (FPSE) requires both accurate thermodynamic and dynamic modelling to predict its performances. The steady state behaviour of the engine partly relies on non linear dissipative phenomena such as pressure drop loss within heat exchangers which is dependant on the temperature within the associated components. An analytical thermodynamic model which encompasses the effectiveness and the flaws of the heat exchangers and the regenerator has been previously developed and validated. A semi-analytical dynamic model of FPSE is developed and presented in this paper. The thermodynamic model is used to define the thermal variables that are used in the dynamic model which evaluates the kinematic results. Thus, a coupled iterative strategy has been used to perform a global simulation. The global modelling approach has been validated using the experimental data available from the NASA RE-1000 Stirling engine prototype. The resulting coupled thermodynamic-dynamic model using a standard...

Formosa, Fabien

2013-01-01T23:59:59.000Z

265

Dynamic models towards operator and engineer training: Virtual environment  

Science Journals Connector (OSTI)

The simulation of chemical processes is an important tool for solving problems in Computer Aided Process Engineering (CAPE) and the use of commercial simulators is essential for this task. In this work, the intention is to create a virtual environment for industrial process and data representations for operator and engineer training. The applications focus on the separation process dynamic and control. The first case is an azeotropic distillation process. It was used an industrial plant data to illustrate the importance of reliable thermodynamic data to the process simulation. The system studied is the ethanol/water separation using cyclohexane as mass separating agent. As the second case, it was used a refinery data to simulate the debutanizer column of a fluid catalytic cracking unit in order to make this complex problem understandable, well represented and easily reproducible in a simulation framework. In this case, optimization, regulatory control, PID tuning and model predictive control were considered. The energy consumption was minimized using the SQP method. Simulations were performed using HYSYS. Plant process simulator.

Claudia J.G. Vasconcelos; Rubens Maciel Filho; Renato Spandri; Maria R. Wolf-Maciel

2005-01-01T23:59:59.000Z

266

Imbedding dynamic responses with imperfect information into static portraits of the regional impact of climate change  

SciTech Connect (OSTI)

It is becoming increasingly clear, at least on a theoretical level, that modelers of the potential impacts of climate change must impose that change upon the world as it will be configured sometime in the future rather than confine their attention to considerations of what would happen to the world as it looks now. Initial baselines which focus on current circumstances are certainly worthwhile points of departure in any study, of course, but the truth is that social, economic, and political systems will evolve as the future unfolds; and careful analysis of that evolution across a globe experiencing changes in its climate must be undertaken, as well. In the vernacular of the analysts' workroom, while it may be interesting to try to see what would happen to dumb farmers'' who continue to do things as they always have regardless of what happens, it is critically important to evaluate the need for any sort of policy response to climate change in a world of smart farmers'' who will have observed the ramifications of climate change and responded in their own best interest. 9 refs., 2 figs.

Yohe, G.W. (Wesleyan Univ., Middletown, CT (USA))

1990-11-01T23:59:59.000Z

267

Modeling Thermodynamics and Dynamics of MixtureModeling Thermodynamics and Dynamics of Mixture Adsorption in Porous MaterialsAdsorption in Porous Materials  

E-Print Network [OSTI]

models to describe adsorption dynamics · Apply to case of Enhanced Coalbed Methane Extraction ­ Trillions of cubic meters of methane and carbon dioxide can be extracted and stored in unusable coal seams Models temperature, adsorption increases with pressure. Carbon Dioxide interacts more strongly with coal than methane

Mountziaris, T. J.

268

Comparison of blood flow models and acquisitions for quantitative myocardial perfusion estimation from dynamic CT  

Science Journals Connector (OSTI)

Myocardial blood flow (MBF) can be estimated from dynamic contrast enhanced (DCE) cardiac CT acquisitions, leading to quantitative assessment of regional perfusion. The need for low radiation dose and the lack of consensus on MBF estimation methods motivates this study to refine the selection of acquisition protocols and models for CT-derived MBF. DCE cardiac CT acquisitions were simulated for a range of flow states (MBF = 0.5, 1, 2, 3 ml (min g)?1, cardiac output = 3, 5, 8 L min?1). Patient kinetics were generated by a mathematical model of iodine exchange incorporating numerous physiological features including heterogenenous microvascular flow, permeability and capillary contrast gradients. CT acquisitions were simulated for multiple realizations of realistic x-ray flux levels. CT acquisitions that reduce radiation exposure were implemented by varying both temporal sampling (1, 2, and 3 s sampling intervals) and tube currents (140, 70, and 25 mAs). For all acquisitions, we compared three quantitative MBF estimation methods (two-compartment model, an axially-distributed model, and the adiabatic approximation to the tissue homogeneous model) and a qualitative slope-based method. In total, over 11 000 time attenuation curves were used to evaluate MBF estimation in multiple patient and imaging scenarios. After iodine-based beam hardening correction, the slope method consistently underestimated flow by on average 47.5% and the quantitative models provided estimates with less than 6.5% average bias and increasing variance with increasing dose reductions. The three quantitative models performed equally well, offering estimates with essentially identical root mean squared error (RMSE) for matched acquisitions. MBF estimates using the qualitative slope method were inferior in terms of bias and RMSE compared to the quantitative methods. MBF estimate error was equal at matched dose reductions for all quantitative methods and range of techniques evaluated. This suggests that there is no particular advantage between quantitative estimation methods nor to performing dose reduction via tube current reduction compared to temporal sampling reduction. These data are important for optimizing implementation of cardiac dynamic CT in clinical practice and in prospective CT MBF trials.

Michael Bindschadler; Dimple Modgil; Kelley R Branch; Patrick J La Riviere; Adam M Alessio

2014-01-01T23:59:59.000Z

269

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

Science Journals Connector (OSTI)

A regional-scale weather model is used to determine the potential for flood forecasting based on model-predicted rainfall. Extreme precipitation and flooding events are a significant concern in central Texas, due to both the high occurrence and ...

Marla R. Knebl Lowrey; Zong-Liang Yang

2008-12-01T23:59:59.000Z

270

Dynamic energy budget approaches for modelling organismal ageing  

Science Journals Connector (OSTI)

...12 November 2010 research-article Articles...Developments in dynamic energy budget theory and...metabolism. The Dynamic Energy Budgets (DEB...uptake and use of energy by living organisms...fate. From a more abstract and generic point...efforts, several research groups have used...

2010-01-01T23:59:59.000Z

271

Development and Validation of the 3-D Computational Fluid Dynamics Model for CANDU-6 Moderator Temperature Predictions  

SciTech Connect (OSTI)

A computational fluid dynamics (CFD) model for predicting the moderator circulation inside the Canada deuterium uranium (CANDU) reactor vessel has been developed to estimate the local subcooling of the moderator in the vicinity of the Calandria tubes. The buoyancy effect induced by internal heating is accounted for by Boussinesq approximation. The standard k-[curly epsilon] turbulence model associated with logarithmic wall treatment is applied to predict the turbulent jet flows from the inlet nozzles. The matrix of the Calandria tubes in the core region is simplified to porous media, in which anisotropic hydraulic impedance is modeled using an empirical correlation of the frictional pressure loss. The governing equations are solved by CFX-4.4, a commercial CFD code developed by AEA Technology. The CFD model has been successfully verified and validated against experimental data obtained at Stern Laboratories Inc. in Hamilton, Ontario, Canada.

Yoon, Churl; Rhee, Bo Wook; Min, Byung-Joo [Korea Atomic Energy Research Institute (Korea, Republic of)

2004-12-15T23:59:59.000Z

272

Applied Dynamic Analysis of the Global Economy (ADAGE) Model | Open Energy  

Open Energy Info (EERE)

Applied Dynamic Analysis of the Global Economy (ADAGE) Model Applied Dynamic Analysis of the Global Economy (ADAGE) Model Jump to: navigation, search LEDSGP green logo.png FIND MORE DIA TOOLS This tool is part of the Development Impacts Assessment (DIA) Toolkit from the LEDS Global Partnership. Tool Summary LAUNCH TOOL Name: Applied Dynamic Analysis of the Global Economy (ADAGE) Model Agency/Company /Organization: Research Triangle Institute Sector: Climate, Energy Topics: Co-benefits assessment, - Macroeconomic, Pathways analysis Resource Type: Software/modeling tools User Interface: Desktop Application Complexity/Ease of Use: Advanced Website: www.rti.org/page.cfm?objectid=DDC06637-7973-4B0F-AC46B3C69E09ADA9 RelatedTo: Electricity Markets Analysis (EMA) Model Cost: Paid Applied Dynamic Analysis of the Global Economy (ADAGE) Model Screenshot

273

Abstract--Eventually, prediction of transformer thermal performance for dynamic loading will be made using models  

E-Print Network [OSTI]

1 Abstract--Eventually, prediction of transformer thermal performance for dynamic loading will be made using models distilled from measure data, rather than models derived from transformer heat for measuring the acceptability of transformer thermal models. For a model to be acceptable, it must have

274

Hierarchical Modeling of Variability in Regional Climate Models Using Markov Random Fields  

E-Print Network [OSTI]

ensembles, are used to explore the uncertainties associated with projections of climate change (ANOVA), climate model ensembles, un- certainty quantification. 1 Geophysical Statistics Project the Earth's climate and producing projections of climate change. They encapsulate an entire field

Kaufman, Cari

275

A model for the formation of the active region corona driven by magnetic flux emergence  

E-Print Network [OSTI]

We present the first model that couples the formation of the corona of a solar active region to a model of the emergence of a sunspot pair. This allows us to study when, where, and why active region loops form, and how they evolve. We use a 3D radiation MHD simulation of the emergence of an active region through the upper convection zone and the photosphere as a lower boundary for a 3D MHD coronal model. The latter accounts for the braiding of the magnetic fieldlines, which induces currents in the corona heating up the plasma. We synthesize the coronal emission for a direct comparison to observations. Starting with a basically field-free atmosphere we follow the filling of the corona with magnetic field and plasma. Numerous individually identifiable hot coronal loops form, and reach temperatures well above 1 MK with densities comparable to observations. The footpoints of these loops are found where small patches of magnetic flux concentrations move into the sunspots. The loop formation is triggered by an incr...

Chen, F; Bingert, S; Cheung, M C M

2014-01-01T23:59:59.000Z

276

Modeling and Algorithm for DynamicModeling and Algorithm for Dynamic Multi-Objective Max-CSPsMulti-Objective Max-CSPs  

E-Print Network [OSTI]

_n is blow m. ­ e.g. m=5 : No (3,3) / Yes (4,1) #12;Multi-Objective Max-CSP (Properties) For a cost vector RModeling and Algorithm for DynamicModeling and Algorithm for Dynamic Multi-Objective Max-CSPsMulti-Objective Max-CSPs Tenda Okimoto ¹², Tony Rebeiro ³, Maxime Clement and Katsumi Inoue ² ¹ Transdisciplinary

Banbara, Mutsunori

277

COMPUTATIONAL FLUID DYNAMICS MODELING OF SCALED HANFORD DOUBLE SHELL TANK MIXING - CFD MODELING SENSITIVITY STUDY RESULTS  

SciTech Connect (OSTI)

The primary purpose of the tank mixing and sampling demonstration program is to mitigate the technical risks associated with the ability of the Hanford tank farm delivery and celtification systems to measure and deliver a uniformly mixed high-level waste (HLW) feed to the Waste Treatment and Immobilization Plant (WTP) Uniform feed to the WTP is a requirement of 24590-WTP-ICD-MG-01-019, ICD-19 - Interface Control Document for Waste Feed, although the exact definition of uniform is evolving in this context. Computational Fluid Dynamics (CFD) modeling has been used to assist in evaluating scaleup issues, study operational parameters, and predict mixing performance at full-scale.

JACKSON VL

2011-08-31T23:59:59.000Z

278

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

279

AN APPLICATION OF URBANSIM TO THE AUSTIN, TEXAS REGION: INTEGRATED-MODEL FORECASTS FOR THE YEAR 2030  

E-Print Network [OSTI]

AN APPLICATION OF URBANSIM TO THE AUSTIN, TEXAS REGION: INTEGRATED-MODEL FORECASTS FOR THE YEAR, as well as energy consumption and greenhouse gas emissions. This work describes the modeling of year-2030 policies significantly impact the region's future land use patterns, traffic conditions, greenhouse gas

Kockelman, Kara M.

280

Modeling regional seismic waves. Final report, 24 Mar 89-31 Jul 91  

SciTech Connect (OSTI)

This study can be divided into three main topics: modeling regional broad-band seismograms from the Imperial Valley to Pasadena, Determining surface wave magnitudes for NTS events using regional data, and waveform modeling to determine depth of earthquakes in Tibet leading to new origin times and a better estimation of P(sub n) and S(sub n) velocities. In section 1, broad-band wave propagation along a corridor from Imperial Valley to Pasadena, California is addressed. The path consists of 50 km of slow basin structure with a shallow moho followed by 250 km of relatively normal Southern California structure approaching Pasadena. In section 2, surface wave magnitudes for 112 Nevada Test Site (NTS) explosions from a data set of regional long-period seismograms from North American stations are calculated. In order to utilize the newer regional stations (Delta < 25 deg), a new method for determining M(sub s) has been developed which employs synthetic seismograms to establish a relationship between the amplitude of the regional Airy phase, or Rayleigh pulse, of the data and an associated surface wave magnitude, based on conventional M(sub s) determinations, calculated from a synthetic seismogram propagated to 40 deg. In section 3, a note on the relocation of the Tibetan earthquake is presented. Present ISC locations for earthquakes beneath Tibet indicates a random distribution of events down to a depth of about 50 km. A detained investigation of the Tibetan earthquakes, with magnitudes greater than 5.5 from 1964 to 1986, yields a distinctly different picture.

Helmberger, D.V.; Harkrider, D.G.

1991-07-31T23:59:59.000Z

Note: This page contains sample records for the topic "regional dynamics model" 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

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

282

Dynamics of the Structural Glass Transition and the p-Spin—Interaction Spin-Glass Model  

Science Journals Connector (OSTI)

The mathematical structure of the dynamical theory for the soft-spin version of the p-spin-interaction (p>2) spin-glass model is related to that for the dynamical theories of the structural glass transition. The phase transitions predicted by both theories are discussed. The spin-glass transition predicted by the dynamical theory is related to a broken-replica-symmetry equilibrium calculation.

T. R. Kirkpatrick and D. Thirumalai

1987-05-18T23:59:59.000Z

283

DYNAMICAL MODEL FOR THE ZODIACAL CLOUD AND SPORADIC METEORS  

SciTech Connect (OSTI)

The solar system is dusty, and would become dustier over time as asteroids collide and comets disintegrate, except that small debris particles in interplanetary space do not last long. They can be ejected from the solar system by Jupiter, thermally destroyed near the Sun, or physically disrupted by collisions. Also, some are swept by the Earth (and other planets), producing meteors. Here we develop a dynamical model for the solar system meteoroids and use it to explain meteor radar observations. We find that the Jupiter Family Comets (JFCs) are the main source of the prominent concentrations of meteors arriving at the Earth from the helion and antihelion directions. To match the radiant and orbit distributions, as measured by the Canadian Meteor Orbit Radar (CMOR) and Advanced Meteor Orbit Radar (AMOR), our model implies that comets, and JFCs in particular, must frequently disintegrate when reaching orbits with low perihelion distance. Also, the collisional lifetimes of millimeter particles may be longer ({approx}> 10{sup 5} yr at 1 AU) than postulated in the standard collisional models ({approx}10{sup 4} yr at 1 AU), perhaps because these chondrule-sized meteoroids are stronger than thought before. Using observations of the Infrared Astronomical Satellite to calibrate the model, we find that the total cross section and mass of small meteoroids in the inner solar system are (1.7-3.5) Multiplication-Sign 10{sup 11} km{sup 2} and {approx}4 Multiplication-Sign 10{sup 19} g, respectively, in a good agreement with previous studies. The mass input required to keep the zodiacal cloud in a steady state is estimated to be {approx}10{sup 4}-10{sup 5} kg s{sup -1}. The input is up to {approx}10 times larger than found previously, mainly because particles released closer to the Sun have shorter collisional lifetimes and need to be supplied at a faster rate. The total mass accreted by the Earth in particles between diameters D = 5 {mu}m and 1 cm is found to be {approx}15,000 tons yr{sup -1} (factor of two uncertainty), which is a large share of the accretion flux measured by the Long Term Duration Facility. The majority of JFC particles plunge into the upper atmosphere at <15 km s{sup -1} speeds, should survive the atmospheric entry, and can produce micrometeorite falls. This could explain the compositional similarity of samples collected in the Antarctic ice and stratosphere, and those brought from comet Wild 2 by the Stardust spacecraft. Meteor radars such as CMOR and AMOR see only a fraction of the accretion flux ({approx}1%-10% and {approx}10%-50%, respectively), because small particles impacting at low speeds produce ionization levels that are below these radars' detection capabilities.

Nesvorny, David; Vokrouhlicky, David; Pokorny, Petr; Bottke, William F. [Department of Space Studies, Southwest Research Institute, 1050 Walnut St., Suite 300, Boulder, CO 80302 (United States); Janches, Diego [Space Weather Laboratory, Code 674, GSFC/NASA, Greenbelt, MD 20771 (United States); Jenniskens, Peter [Carl Sagan Center, SETI Institute, 515 N. Whisman Road, Mountain View, CA 94043 (United States)

2011-12-20T23:59:59.000Z

284

Towards Modeling Dynamic Behavior with Integrated Qualitative Spatial Relations  

Science Journals Connector (OSTI)

Situation awareness and geographic information systems in dynamic spatial systems such as road traffic management (RTM) aim to detect and predict critical situations on the basis of relations between entities....

Stefan Mitsch; Werner Retschitzegger…

2011-01-01T23:59:59.000Z

285

Dynamic reduced order modeling of entrained flow gasifiers  

E-Print Network [OSTI]

Gasification-based energy systems coupled with carbon dioxide capture and storage technologies have the potential to reduce greenhouse gas emissions from continued use of abundant and secure fossil fuels. Dynamic reduced ...

Monaghan, Rory F. D. (Rory Francis Desmond)

2010-01-01T23:59:59.000Z

286

Dynamical Modeling of Economy in Global Nuclear Energy Market  

Science Journals Connector (OSTI)

Non-linear dynamical analysis for the global nuclear energy market is investigated. Currently, the market means a different characteristics comparing to the ... between two countries, which depends on the energy ...

Taeho Woo

2012-01-01T23:59:59.000Z

287

Structural models of bioactive glasses from molecular dynamics simulations  

Science Journals Connector (OSTI)

...to adsorb and dissociate a water molecule (Tilocca Cormack 2008...the available computational power steadily grows, it will become...surface of bioactive glasses: water adsorption and reactivity...soda-lime silicate glasses by Car-Parrinello molecular dynamics...

2009-01-01T23:59:59.000Z

288

Predicting and understanding forest dynamics using a simple tractable model  

E-Print Network [OSTI]

the dynamics of size distributions and wood volume and, hence, carbon in even-aged plantation monocul- tures patterns in the biomass, structure, and species composition of forests (4). This problem limits our ability

Lichstein, Jeremy W.

289

Latitude Based Model for Tilt Angle Optimization for Solar Collectors in the Mediterranean Region  

Science Journals Connector (OSTI)

Abstract This paper inspects the different parameters that intervene in the determination of the optimal tilt angle for maximum solar energy collection. It proposes a method for calculating the optimal tilt angle based upon the values of the daily global solar radiation on a horizontal surface. A computer program using the mathematical model to calculate the solar radiation incident on an inclined surface as a function of the tilt angle is implemented. Four years data of daily global solar radiation on a horizontal surface in 35 sites in different countries of the Mediterranean region is used. The program assumes a due south orientation of the collectors and it determines the optimal tilt angle for maximum solar radiation collection for sites in the Mediterranean region. A regression analysis using the results of the computer simulation is conducted to develop a latitude based tilt angle optimization mathematical model for maximum solar radiation collection for the sites. We tested both a linear and a quadratic model (of the form ax2+bx) for representing the relationship between the annual optimal tilt angle and the site's latitude. The quadratic model is better; it provides very high prediction accuracy. 99.87% of the variation in the annual optimal tilt angle is explained by the variability in site's latitude with an average residual angle of only 0.96° for all 35 sites studied. It also gives an average percentage decrease in the annual solar radiation of only 0.016% when compared with actual optimal tilt angles.

Hassane Darhmaoui; Driss Lahjouji

2013-01-01T23:59:59.000Z

290

Offshore floating vertical axis wind turbines, dynamics modelling state of the art. Part II: Mooring line and structural dynamics  

Science Journals Connector (OSTI)

Abstract The need to exploit enhanced wind resources far offshore as well as in deep waters requires the use of floating support structures to become economically viable. The conventional three-bladed horizontal axis wind turbine may not continue to be the optimal design for floating applications. Therefore it is important to assess alternative concepts in this context that may be more suitable. Vertical axis wind turbines (VAWTs) are a promising concept, and it is important to first understand the coupled and relatively complex dynamics of floating \\{VAWTs\\} to assess their technical feasibility. As part of this task, a series of articles have been developed to present a comprehensive literature review covering the various areas of engineering expertise required to understand the coupled dynamics involved in floating VAWTs. This second article focuses on the modelling of mooring systems and structural behaviour of floating VAWTs, discussing various mathematical models and their suitability within the context of developing a model of coupled dynamics. Emphasis is placed on computational aspects of model selection and development as computational efficiency is an important aspect during preliminary design stages. This paper has been written both for researchers new to this research area, outlining underlying theory whilst providing a comprehensive review of the latest work, and for experts in this area, providing a comprehensive list of the relevant references where the details of modelling approaches may be found.

Michael Borg; Maurizio Collu; Athanasios Kolios

2014-01-01T23:59:59.000Z

291

A two-dimensional regional basin model of Williston basin hydrocarbon systems  

SciTech Connect (OSTI)

Institut Francais du Petrole`s two-dimensional model, TEMISPACK, is used to discuss the functioning of petroleum systems in the Williston basin along a 330-km-long section, focusing on four regional source intervals: Ordovician Yeoman formation, Lower Devonian Winnipegosis Formation, Upper Devonian-Lower Mississippian Bakken Formation, and Mississippian Lodgepole formation. Thermal history calibration against present temperature and source rock maturity profiles suggests that the Williston basin can be divided into a region of constant heat flow of about 55 mW/m{sup 2} away from the Nesson anticline, and a region of higher heat flow and enhanced thermal maturity in the vicinity of the Nesson anticline. Original kinetic parameters used in the calibration were derived for each of the four source rocks from Rock-Eval yield curves. Bakken overpressures are entirely due to oil generation, not compaction disequilibrium. Very low Bakken vertical permeabilities range from 0.01 to 0.001 and are matched against observed overpressures, whereas Bakken porosities based on the model and confirmed by measurements are inferred to be also unusually low, around 3%.

Burrus, J.; Wolf, S.; Doligez, B. [Institut Francais due Petrole, Rueil-Malmaison (France)] [and others

1996-02-01T23:59:59.000Z

292

Modeling DNA in Confinement: A Comparison between the Brownian Dynamics and Lattice Boltzmann Method  

E-Print Network [OSTI]

Modeling DNA in Confinement: A Comparison between the Brownian Dynamics and Lattice Boltzmann from both the lattice Boltzmann method (LBM) and the Brownian dynamics simulations with fluctuating. We find that the lattice Boltzmann method is well-suited for long polymer chains as well

293

LIDAR measurements of wind turbine wake dyn_amics and comparison with an engineering model  

E-Print Network [OSTI]

LIDAR measurements of wind turbine wake dyn_amics and comparison with an engineering model 1 dynamics, lIre performed at four diameters behind a 95 kW wind turbine. The wake 111eaeasurement technique allows esti111ation of qUClsiinstantancou~ two dimensional wind fields in an area

294

Interoperability between a dynamic reliability modeling and a Systems Engineering process Principles and Case Study  

E-Print Network [OSTI]

element for interoperability with the tools and activities required for a dynamic reliability assessment. The case study is the dynamic assessment of availability of a feed-water control system in a power plant steam generator, presented in previous articles. Keywords: Systems engineering, systems modeling, RAMS

Paris-Sud XI, Université de

295

An Energy-Aware Simulation Model and Transaction Protocol for Dynamic Workload Distribution in Mobile Ad Hoc Networks1  

E-Print Network [OSTI]

An Energy-Aware Simulation Model and Transaction Protocol for Dynamic Workload Distribution California {tari, prong, pedram}@usc.edu Abstract This paper introduces a network simulation model

Pedram, Massoud

296

Does the Danube exist? Versions of reality given by various regional climate models and climatological datasets  

E-Print Network [OSTI]

We present an intercomparison and verification analysis of several regional climate models (RCMs) nested into the same run of the same Atmospheric Global Circulation Model (AGCM) regarding their representation of the statistical properties of the hydrological balance of the Danube river basin for 1961-1990. We also consider the datasets produced by the driving AGCM, from the ECMWF and NCEP-NCAR reanalyses. The hydrological balance is computed by integrating the precipitation and evaporation fields over the area of interest. Large discrepancies exist among RCMs for the monthly climatology as well as for the mean and variability of the annual balances, and only few datasets are consistent with the observed discharge values of the Danube at its Delta, even if the driving AGCM provides itself an excellent estimate. Since the considered approach relies on the mass conservation principle and bypasses the details of the air-land interface modeling, we propose that the atmospheric components of RCMs still face diffic...

Lucarini, V; Kriegerova, I; Speranza, A; Danihlik, Robert; Kriegerova, Ida; Lucarini, Valerio; Speranza, Antonio

2006-01-01T23:59:59.000Z

297

Using Realistic MHD Simulations for Modeling and Interpretation of Quiet-Sun Observations with the Solar Dynamics Observatory Helioseismic and Magnetic Imager  

E-Print Network [OSTI]

The solar atmosphere is extremely dynamic, and many important phenomena develop on small scales that are unresolved in observations with the Helioseismic and Magnetic Imager (HMI) instrument on the Solar Dynamics Observatory (SDO). For correct calibration and interpretation, it is very important to investigate the effects of small-scale structures and dynamics on the HMI observables, such as Doppler shift, continuum intensity, spectral line depth, and width. We use 3D radiative hydrodynamics simulations of the upper turbulent convective layer and the atmosphere of the Sun, and a spectro-polarimetric radiative transfer code to study observational characteristics of the Fe I 6173A line observed by HMI in quiet-Sun regions. We use the modeling results to investigate the sensitivity of the line Doppler shift to plasma velocity, and also sensitivities of the line parameters to plasma temperature and density, and determine effective line formation heights for observations of solar regions located at different dista...

Kitiashvili, Irina N; Lagg, Andreas

2014-01-01T23:59:59.000Z

298

Observed Scaling in Clouds and Precipitation and Scale Incognizance in Regional to Global Atmospheric Models  

SciTech Connect (OSTI)

We use observations of robust scaling behavior in clouds and precipitation to derive constraints on how partitioning of precipitation should change with model resolution. Our analysis indicates that 90-99% of stratiform precipitation should occur in clouds that are resolvable by contemporary climate models (e.g., with 200 km or finer grid spacing). Furthermore, this resolved fraction of stratiform precipitation should increase sharply with resolution, such that effectively all stratiform precipitation should be resolvable above scales of ~50 km. We show that the Community Atmosphere Model (CAM) and the Weather Research and Forecasting (WRF) model also exhibit the robust cloud and precipitation scaling behavior that is present in observations, yet the resolved fraction of stratiform precipitation actually decreases with increasing model resolution. A suite of experiments with multiple dynamical cores provides strong evidence that this `scale-incognizant' behavior originates in one of the CAM4 parameterizations. An additional set of sensitivity experiments rules out both convection parameterizations, and by a process of elimination these results implicate the stratiform cloud and precipitation parameterization. Tests with the CAM5 physics package show improvements in the resolution-dependence of resolved cloud fraction and resolved stratiform precipitation fraction.

O'Brien, Travis A.; Li, Fuyu; Collins, William D.; Rauscher, Sara; Ringler, Todd; Taylor, Mark; Hagos, Samson M.; Leung, Lai-Yung R.

2013-12-01T23:59:59.000Z

299

Dynamic Evolution of an X-shaped Structure above a Trans-equatorial Quadrupole Solar Active Region Group  

E-Print Network [OSTI]

In the solar corona, magnetic reconnection usually takes place at the singular configuration of magnetic field, in particular near a magnetic null owing to its high susceptibility to perturbations. In this Letter, we report a rare X-shaped structure, encompassing a magnetic null, above a trans-equatorial quadrupole active region group that is well observed by the Atmospheric Imaging Assembly (AIA). The observations show that this X-shaped structure is visible in all AIA EUV passbands and stably exists for days. However, possibly induced by flare activities at the northern part of the quadrupole active region group, the X-shaped structure starts to destabilize and meanwhile a jet erupted near its center at 15:05 UT on 2013 October 7. Through the non-linear force-free field modeling, we identify a magnetic null, which is above the quadrupole polarities and well corresponds to the X-shaped structure. After the jet eruption, the temperature and emission measure of the plasma near the X-shaped structure rise from ...

Sun, J Q; Guo, Y; Ding, M D; Li, Y

2014-01-01T23:59:59.000Z

300

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

SciTech Connect (OSTI)

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

Note: This page contains sample records for the topic "regional dynamics model" 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

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

SciTech Connect (OSTI)

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

302

Spatial Variation of Soil Type and Soil Moisture in the Regional Atmospheric Modeling System  

SciTech Connect (OSTI)

Soil characteristics (texture and moisture) are typically assumed to be initially constant when performing simulations with the Regional Atmospheric Modeling System (RAMS). Soil texture is spatially homogeneous and time-independent, while soil moisture is often spatially homogeneous initially, but time-dependent. This report discusses the conversion of a global data set of Food and Agriculture Organization (FAO) soil types to RAMS soil texture and the subsequent modifications required in RAMS to ingest this information. Spatial variations in initial soil moisture obtained from the National Center for Environmental Predictions (NCEP) large-scale models are also introduced. Comparisons involving simulations over the southeastern United States for two different time periods, one during warmer, more humid summer conditions, and one during cooler, dryer winter conditions, reveals differences in surface conditions related to increases or decreases in near-surface atmospheric moisture con tent as a result of different soil properties. Three separate simulation types were considered. The base case assumed spatially homogeneous soil texture and initial soil moisture. The second case assumed variable soil texture and constant initial soil moisture, while the third case allowed for both variable soil texture and initial soil moisture. The simulation domain was further divided into four geographically distinct regions. It is concluded there is a more dramatic impact on thermodynamic variables (surface temperature and dewpoint) than on surface winds, and a more pronounced variability in results during the summer period. While no obvious trends in surface winds or dewpoint temperature were found relative to observations covering all regions and times, improvement in surface temperatures in most regions and time periods was generally seen with the incorporation of variable soil texture and initial soil moisture.

Buckley, R.

2001-06-27T23:59:59.000Z

303

Ensemble regression : using ensemble model output for atmospheric dynamics and prediction  

E-Print Network [OSTI]

Ensemble regression (ER) is a linear inversion technique that uses ensemble statistics from atmospheric model output to make dynamical inferences and forecasts. ER defines a multivariate regression operator using ensemble ...

Gombos, Daniel (Daniel Lawrence)

2009-01-01T23:59:59.000Z

304

Dynamic soil-structure interaction-comparison of FEM model with experimental results  

E-Print Network [OSTI]

to represent twenty different laboratory experiments. The results of these models are compared with results available from extensive experimental dynamic testing on a geotechnical centrifuge. Though the various results from the finite element analysis...

Srinivasan, Palanivel Rajan

2012-06-07T23:59:59.000Z

305

Finite Element Modelling and Molecular Dynamic Simulations of Carbon nanotubes/ Polymer Composites  

E-Print Network [OSTI]

Modeling of single-walled carbon nanotubes, multi-walled nanotubes and nanotube reinforced polymer composites using both the Finite Element method and the Molecular Dynamic simulation technique is presented. Nanotubes subjected to mechanical loading...

Gaddamanugu, Dhatri

2010-07-14T23:59:59.000Z

306

A dynamic model of a self-vibration cycle in a stirling engine with opposed cylinders  

Science Journals Connector (OSTI)

A dynamic model of the self-vibration cycle in an engine with opposed cylinders and two pistons located on a common guide bar is studied. To each cylinder containing a working liquid, a pair of hydraulic accum...

M. Ya. Izrailovich; A. V. Sinev…

2007-06-01T23:59:59.000Z

307

Constraining dynamical dark energy models through the abundance of high-redshift supermassive black holes  

Science Journals Connector (OSTI)

......Constraining dynamical dark energy models through the abundance...its contribution to the energy density would become rapidly...provided by the NASA Joint Dark Energy Mission (JDEM) -Wide-Field Infrared Survey Telescope (WFIRST) space......

A. Lamastra; N. Menci; F. Fiore; C. Di Porto; L. Amendola

2012-03-01T23:59:59.000Z

308

Model predictive controller design for the dynamic positioning system of a semi-submersible platform  

Science Journals Connector (OSTI)

This paper researches how to apply the advanced control technology of model predictive control (MPC) to the design of the dynamic positioning system (DPS) of a semi-submersible platform. First, a linear low-frequ...

Hongli Chen; Lei Wan; Fang Wang…

2012-09-01T23:59:59.000Z

309

A Mechanical Fluid-Dynamical Model For Ground Movements At Campi...  

Open Energy Info (EERE)

Mechanical Fluid-Dynamical Model For Ground Movements At Campi Flegrei Caldera Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: A Mechanical...

310

A Dynamic household Alternative-fuel Vehicle Demand Model Using Stated and Revealed Transaction Information  

E-Print Network [OSTI]

market share for alternative-fuel vehicles drop from thePreferences for Alternative-Fuel Vehicles”, Brownstone DavidA Dynamic Household Alternative-fuel Vehicle Demand Model

Sheng, Hongyan

1999-01-01T23:59:59.000Z

311

Groundwater pollution from agrochemicals — A dynamic model of externalities and policy options  

Science Journals Connector (OSTI)

A dynamic model of groundwater pollution from intensive agrochemical use is developed in this paper to capture the possible externalities and analyze various policy options in protecting groundwater resources. Fo...

Suresh Chandra Babu; B. Thirumalai Nivas; B. Rajasekaran

1992-01-01T23:59:59.000Z

312

Modeling the Complex Dynamics of Distributed Communities of the Web with Pretopology  

E-Print Network [OSTI]

Modeling the Complex Dynamics of Distributed Communities of the Web with Pretopology Vincent analysis of web communities. This approach is based upon the pretopological concepts of pseudoclosure through the actual limits of graph theory modeling. The problem of modeling and understanding web

313

Pseudo Dynamic Transitional Modeling of Building Heating Energy Demand Using Artificial1 Neural Network2  

E-Print Network [OSTI]

Transitional Modeling of Building Heating Energy Demand Using Artificial1 Neural Network2 Subodh Paudel a.Lecorre@mines-nantes.fr9 Abstract10 This paper presents the building heating demand prediction model with occupancy profile Institution15 building and compared its results with static and other pseudo dynamic neural network models

Paris-Sud XI, Université de

314

Model-based control strategies in the dynamic interaction of air supply and fuel cell  

E-Print Network [OSTI]

Model-based control strategies in the dynamic interaction of air supply and fuel cell M Grujicic1Ã? fuel cell temperature. The model is used to analyse the control of the fuel cell system with respect, University of Michigan, Ann Arbor, Michigan, USA Abstract: Model-based control strategies are utilized

Grujicic, Mica

315

Small-signal dynamic model of a micro-grid including conventional and electronically  

E-Print Network [OSTI]

Small-signal dynamic model of a micro-grid including conventional and electronically interfaced-signal modelling of a micro-grid system that includes conventional (rotating machine) and electronically interfaced deviations in the overall system model and provides a methodology for the analysis of autonomous micro-grid

Lehn, Peter W.

316

Transmission Dynamics of an Influenza Model with Age of Infection ...  

E-Print Network [OSTI]

viral treatment and drug-resistance. In this paper, we consider an influenza model which includes an age of infection. The model includes partial differential ...

2010-07-20T23:59:59.000Z

317

Quantification of model mismatch errors of the dynamic energy distribution in a stirred-tank reactor  

E-Print Network [OSTI]

QUANTIFICATION OF MODEL MISMATCH ERRORS OF THE DYNAMIC ENERGY DISTRIBUTION IN A STIRRED- TANK REACTOR A Thesis by MARK RAYMOND KIMMICH Submitted to the Graduate College of Texas AkM University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE August 198i Major Subject: Chemical Engineering QUANTIFICATION OF MODEL MISMATCH ERRORS OF THE DYNAMIC ENERGY DISTRIBUTION IN A STIRRED-TANK REACTOR A Thesis by MARK RAYMOND KIMMICH Approved as to style and content by...

Kimmich, Mark Raymond

1987-01-01T23:59:59.000Z

318

Generator Dynamic Model Validation and Parameter Calibration Using Phasor Measurements at the Point of Connection  

SciTech Connect (OSTI)

Disturbance data recorded by phasor measurement units (PMU) offers opportunities to improve the integrity of dynamic models. However, manually tuning parameters through play-back events demands significant efforts and engineering experiences. In this paper, a calibration method using the extended Kalman filter (EKF) technique is proposed. The formulation of EKF with parameter calibration is discussed. Case studies are presented to demonstrate its validity. The proposed calibration method is cost-effective, complementary to traditional equipment testing for improving dynamic model quality.

Huang, Zhenyu; Du, Pengwei; Kosterev, Dmitry; Yang, Steve

2013-05-01T23:59:59.000Z

319

Dynamic modeling and simulation of a solar-assisted multi-effect distillation plant  

Science Journals Connector (OSTI)

Abstract This paper presents a dynamic model of a solar-assisted multi-effect distillation (MED) plant, carrying on with the previous work “Dynamic modeling and performance of the first cell of a multi-effect distillation plant” (de la Calle et al., 2014). The dynamic model has been designed according to the experience with an experimental solar thermal desalination system erected at CIEMAT-Plataforma Solar de Almería (PSA). The mathematical formulation based on physical principles describes the main heat and mass transfer phenomena in this kind of facilities. The model was implemented using the equation-based object-oriented Modelica modeling language. Based on a modular and hierarchical modeling, different specific-phenomenon submodels have been developed. They have been interconnected between them, thus making a three level deep hierarchy. All the submodels have been calibrated and validated with experimental data. The numerical predictions show a good agreement with measured data.

Alberto de la Calle; Javier Bonilla; Lidia Roca; Patricia Palenzuela

2015-01-01T23:59:59.000Z

320

Characteristics of identifying linear dynamic models from impulse response data using Prony analysis  

SciTech Connect (OSTI)

The purpose of the study was to investigate the characteristics of fitting linear dynamic models to the impulse response of oscillatory dynamic systems using Prony analysis. Many dynamic systems exhibit oscillatory responses with multiple modes of oscillations. Although the underlying dynamics of such systems are often nonlinear, it is frequently possible and very useful to represent the system operating about some set point with a linear model. Derivation of such linear models can be done using two basic approaches: model the system using theoretical derivations and some linearization method such as a Taylor series expansion; or use a curve-fitting technique to optimally fit a linear model to specified system response data. Prony analysis belongs to the second class of system modeling because it is a method of fitting a linear model to the impulse response of a dynamic system. Its parallel formulation inherently makes it well suited for fitting models to oscillatory system data. Such oscillatory dynamic effects occur in large synchronous-generator-based power systems in the form of electromechanical oscillations. To study and characterize these oscillatory dynamics, BPA has developed computer codes to analyze system data using Prony analysis. The objective of this study was to develop a highly detailed understanding of the properties of using Prony analysis to fit models to systems with characteristics often encountered in power systems. This understanding was then extended to develop general rules-of-thumb'' for using Prony analysis. The general characteristics were investigated by performing fits to data from known linear models under controlled conditions. The conditions studied include various mathematical solution techniques; different parent system configurations; and a large variety of underlying noise characteristics.

Trudnowski, D.J.

1992-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "regional dynamics model" 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

Characteristics of identifying linear dynamic models from impulse response data using Prony analysis  

SciTech Connect (OSTI)

The purpose of the study was to investigate the characteristics of fitting linear dynamic models to the impulse response of oscillatory dynamic systems using Prony analysis. Many dynamic systems exhibit oscillatory responses with multiple modes of oscillations. Although the underlying dynamics of such systems are often nonlinear, it is frequently possible and very useful to represent the system operating about some set point with a linear model. Derivation of such linear models can be done using two basic approaches: model the system using theoretical derivations and some linearization method such as a Taylor series expansion; or use a curve-fitting technique to optimally fit a linear model to specified system response data. Prony analysis belongs to the second class of system modeling because it is a method of fitting a linear model to the impulse response of a dynamic system. Its parallel formulation inherently makes it well suited for fitting models to oscillatory system data. Such oscillatory dynamic effects occur in large synchronous-generator-based power systems in the form of electromechanical oscillations. To study and characterize these oscillatory dynamics, BPA has developed computer codes to analyze system data using Prony analysis. The objective of this study was to develop a highly detailed understanding of the properties of using Prony analysis to fit models to systems with characteristics often encountered in power systems. This understanding was then extended to develop general ``rules-of-thumb`` for using Prony analysis. The general characteristics were investigated by performing fits to data from known linear models under controlled conditions. The conditions studied include various mathematical solution techniques; different parent system configurations; and a large variety of underlying noise characteristics.

Trudnowski, D.J.

1992-12-01T23:59:59.000Z

322

Modeling of polarization curves not exhibiting a Tafel region using Excel spreadsheets  

Science Journals Connector (OSTI)

Abstract This paper describes the modeling of polarization curves not exhibiting a Tafel region using Excel spreadsheets. Carbon steel in aerated NaCl unbuffered solutions was studied applying a linear potential sweep technique. Current–potential curves were obtained from linear potential sweep at a rate of 10 mV s?1 in un-buffered 0.1, 0.4 and 0.9 M NaCl solutions, at a constant temperature of 25 °C and potential sweeps that were conducted in a potential range ?1.0 to 0.4 V vs. Ag/AgCl.

Marco Alfaro

2014-01-01T23:59:59.000Z

323

Dynamic Models for Liquid Rocket Engines with Health Monitoring Application  

E-Print Network [OSTI]

) is considered and reviewed, taking as a reference the thermodynamic model introduced by Rocketdyne

324

Dynamically dimensioned search algorithm for computationally efficient watershed model calibration  

E-Print Network [OSTI]

search (DDS), is introduced for automatic calibration of watershed simulation models. DDS is designed. Introduction [2] Almost all watershed simulation models contain effective physical and/or conceptual model. This study will focus on the automatic calibration of watershed simulation models. The results of this study

Hutter, Frank

325

Regional groundwater flow model for C, K. L. and P reactor areas, Savannah River Site, Aiken, SC  

SciTech Connect (OSTI)

A regional groundwater flow model encompassing approximately 100 mi2 surrounding the C, K, L, and P reactor areas has been developed. The reactor flow model is designed to meet the planning objectives outlined in the General Groundwater Strategy for Reactor Area Projects by providing a common framework for analyzing groundwater flow, contaminant migration and remedial alternatives within the Reactor Projects team of the Environmental Restoration Department. The model provides a quantitative understanding of groundwater flow on a regional scale within the near surface aquifers and deeper semi-confined to confined aquifers. The model incorporates historical and current field characterization data up through Spring 1999. Model preprocessing is automated so that future updates and modifications can be performed quickly and efficiently. The CKLP regional reactor model can be used to guide characterization, perform scoping analyses of contaminant transport, and serve as a common base for subsequent finer-scale transport and remedial/feasibility models for each reactor area.

Flach, G.P.

2000-02-11T23:59:59.000Z

326

The sine-Gordon model and the small. kappa. sup + region of light- cone perturbation theory  

SciTech Connect (OSTI)

The non-perturbative ultraviolet divergence of the sine-Gordon model is used to study the k{sup +} = 0 region of light-cone perturbation theory. The light-cone vacuum is shown to be unstable at the non- perturbative {beta}{sup 2} = 8{pi} critical point by a light-cone version of Coleman's variational method. Vacuum bubbles, which are k{sup +} = 0 diagram in light-cone field theory and are individually finite and non-vanishing for all {beta}, conspire to generate ultraviolet divergences of the light-cone energy density. The k{sup +} = 0 region of momentum also contributed to connected Green's functions: the connected two point function will not diverge, as it should, at the critical point unless diagrams which contribute only at k {sup +} = 0 are properly included. This analysis shows in a simple way how the k {sup +} = 0 region cannot be ignored even for connected diagrams. This phenomenon is expected to occur in higher dimensional gauge theories starting at two loop order in light-cone perturbation theory.

Griffin, P.A.

1992-01-01T23:59:59.000Z

327

An application of a puff dispersion model on power plant emissions in Yatagan region, Turkey  

Science Journals Connector (OSTI)

The present paper describes the application of the CALMET meteorological model and CALPUFF plume dispersion model to the Yatagan district to study the impact of Yatagan Power Plant emissions on the SO2 levels on December 2000 in the region. Results indicate that SO2 concentrations over the city depend strongly on advected emissions from the power plant and on the local variation of the wind field and limited vertical mixing conditions. It is found that South Westerly and light winds and the night time surface inversion layers lead to accumulation of pollutants coming from the power plant over the Yatagan district. The results are compared with the observations obtained from Local Environmental Authorities of Mugla. The simulation results indicate that the maximum ground level concentrations were found northeast from the source, which agrees with the measurements, but differ in terms of magnitudes.

Ulas Im; Orhan Yenigun

2005-01-01T23:59:59.000Z

328

Generalized CP symmetries and special regions of parameter space in the two-Higgs-doublet model  

SciTech Connect (OSTI)

We consider the impact of imposing generalized CP symmetries on the Higgs sector of the two-Higgs-doublet model, and identify three classes of symmetries. Two of these classes constrain the scalar potential parameters to an exceptional region of parameter space, which respects either a Z{sub 2} discrete flavor symmetry or a U(1) symmetry. We exhibit a basis-invariant quantity that distinguishes between these two possible symmetries. We also show that the consequences of imposing these two classes of CP symmetry can be achieved by combining Higgs family symmetries, and that this is not possible for the usual CP symmetry. We comment on the vacuum structure and on renormalization in the presence of these symmetries. Finally, we demonstrate that the standard CP symmetry can be used to build all the models we identify, including those based on Higgs family symmetries.

Ferreira, P. M. [Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emidio Navarro, 1900 Lisboa (Portugal); Centro de Fisica Teorica e Computacional, Faculdade de Ciencias, Universidade de Lisboa, Av. Prof. Gama Pinto 2, 1649-003 Lisboa (Portugal); Haber, Howard E. [Santa Cruz Institute for Particle Physics, University of California, Santa Cruz, California 95064 (United States); Silva, Joao P. [Instituto Superior de Engenharia de Lisboa, Rua Conselheiro Emidio Navarro, 1900 Lisboa (Portugal); Centro de Fisica Teorica de Particulas, Instituto Superior Tecnico, P-1049-001 Lisboa (Portugal)

2009-06-01T23:59:59.000Z

329

Using Local and Regional Air Quality Modeling and Source Apportionment Tools to Evaluate Vehicles and Biogenic Emission Factors  

E-Print Network [OSTI]

and inventories of CO, NO_(x) and VOCs from on-road vehicles estimated by vehicle emission factor models and biogenic emissions of isoprene estimated by a popular biogenic emission model are evaluated using local and regional scale air quality modeling and source...

Kota, Sri H

2014-07-25T23:59:59.000Z

330

Conceptual model for regional radionuclide transport from a basalt repository site. Final draft, technical memorandum  

SciTech Connect (OSTI)

This technical memorandum was prepared to: (1) describe a typical basalt radionuclide repository site, (2) describe geologic and hydrologic processes associated with regional radionuclide transport in basalts, (3) define the parameters required to model regional radionuclide transport from a basalt repository site, and (4) develop a ''conceptual model'' of radionuclide transport from a basalt repository site. In a general hydrological sense, basalts may be described as layered sequences of aquifers and aquitards. The Columbia River Basalt, centered near the semi-arid Pasco Basin, is considered by many to be typical basalt repository host rock. Detailed description of the flow system including flow velocities with high-low hydraulic conductivity sequences are not possible with existing data. However, according to theory, waste-transport routes are ultimately towards the Columbia River and the lengths of flow paths from the repository to the biosphere may be relatively short. There are many physical, chemical, thermal, and nuclear processes with associated parameters that together determine the possible pattern of radionuclide migration in basalts and surrounding formations. Brief process descriptions and associated parameter lists are provided. Emphasis has been placed on the use of the distribution coefficient in simulating ion exchange. The use of the distribution coefficient approach is limited because it takes into account only relatively fast mass transfer processes. In general, knowledge of hydrogeochemical processes is primitive.

Walton, W.C.; Voorhees, M.L.; Prickett, T.A.

1980-05-23T23:59:59.000Z

331

A nanoflare model for active region radiance: application of artificial neural networks  

E-Print Network [OSTI]

Context. Nanoflares are small impulsive bursts of energy that blend with and possibly make up much of the solar background emission. Determining their frequency and energy input is central to understanding the heating of the solar corona. One method is to extrapolate the energy frequency distribution of larger individually observed flares to lower energies. Only if the power law exponent is greater than 2, is it considered possible that nanoflares contribute significantly to the energy input. Aims. Time sequences of ultraviolet line radiances observed in the corona of an active region are modelled with the aim of determining the power law exponent of the nanoflare energy distribution. Methods. A simple nanoflare model based on three key parameters (the flare rate, the flare duration time, and the power law exponent of the flare energy frequency distribution) is used to simulate emission line radiances from the ions Fe XIX, Ca XIII, and Si iii, observed by SUMER in the corona of an active region as it rotates around the east limb of the Sun. Light curve pattern recognition by an Artificial Neural Network (ANN) scheme is used to determine the values. Results. The power law exponents, alpha 2.8, 2.8, and 2.6 for Fe XIX, Ca XIII, and Si iii respectively. Conclusions. The light curve simulations imply a power law exponent greater than the critical value of 2 for all ion species. This implies that if the energy of flare-like events is extrapolated to low energies, nanoflares could provide a significant contribution to the heating of active region coronae.

M. Bazarghan; H. Safari; D. E. Innes; E. Karami; S. K. Solanki

2008-08-28T23:59:59.000Z

332

Variational Inference in Stochastic Dynamic Environmental Models Dan Cornford1  

E-Print Network [OSTI]

on related phenomena, such as flooding and storm damage, and on the spread of pollutants. The models needed of the atmosphere even at the resolution of the model. This is especially problematic if the simulation

Roulstone, Ian

333

A dynamic process model of a natural gas combined cycle -- Model development with startup and shutdown simulations  

SciTech Connect (OSTI)

Research in dynamic process simulation for integrated gasification combined cycles (IGCC) with carbon capture has been ongoing at the National Energy Technology Laboratory (NETL), culminating in a full operator training simulator (OTS) and immersive training simulator (ITS) for use in both operator training and research. A derivative work of the IGCC dynamic simulator has been a modification of the combined cycle section to more closely represent a typical natural gas fired combined cycle (NGCC). This paper describes the NGCC dynamic process model and highlights some of the simulator’s current capabilities through a particular startup and shutdown scenario.

Liese, Eric [U.S. DOE; Zitney, Stephen E. [U.S. DOE

2013-01-01T23:59:59.000Z

334

Control Oriented Dynamic Modeling of a Turbocharged Diesel Engine  

Science Journals Connector (OSTI)

To build a precise model is a key issue in fulfilling on optimal control of the turbocharged diesel engine. Meanvalue model has been extensively used for engine control, but neglects the scavenging efficiency. On the basis of carefully considering air-fuel ... Keywords: Diesel engine, mean-value model, AFR

Haiyan Wang; Jundong Zhang

2006-10-01T23:59:59.000Z

335

Estimates of Twenty-First-Century Flood Risk in the Pacific Northwest Based on Regional Climate Model Simulations  

Science Journals Connector (OSTI)

Results from a regional climate model simulation show substantial increases in future flood risk (2040–69) in many Pacific Northwest river basins in the early fall. Two primary causes are identified: 1) more extreme and earlier storms and 2) ...

Eric P. Salathé Jr.; Alan F. Hamlet; Clifford F. Mass; Se-Yeun Lee; Matt Stumbaugh; Richard Steed

2014-10-01T23:59:59.000Z

336

Hydrological Processes in Regional Climate Model Simulations of the Central United States Flood of June–July 1993  

Science Journals Connector (OSTI)

Thirteen regional climate model (RCM) simulations of June–July 1993 were compared with each other and observations. Water vapor conservation and precipitation characteristics in each RCM were examined for a 10° × 10° subregion of the upper ...

Christopher J. Anderson; Raymond W. Arritt; Zaitao Pan; Eugene S. Takle; William J. Gutowski Jr.; Francis O. Otieno; Renato da Silva; Daniel Caya; Jens H. Christensen; Daniel Lüthi; Miguel A. Gaertner; Clemente Gallardo; Filippo Giorgi; René Laprise; Song-You Hong; Colin Jones; H-M. H. Juang; J. J. Katzfey; John L. McGregor; William M. Lapenta; Jay W. Larson; John A. Taylor; Glen E. Liston; Roger A. Pielke Sr.; John O. Roads

2003-06-01T23:59:59.000Z

337

On an improved sub-regional water resources management representation for integration into earth system models  

SciTech Connect (OSTI)

Human influence on the hydrologic cycle includes regulation and storage, consumptive use and overall redistribution of water resources in space and time. Representing these processes is essential for applications of earth system models in hydrologic and climate predictions, as well as impact studies at regional to global scales. Emerging large-scale research reservoir models use generic operating rules that are flexible for coupling with earth system models. Those generic operating rules have been successful in reproducing the overall regulated flow at large basin scales. This study investigates the uncertainties of the reservoir models from different implementations of the generic operating rules using the complex multi-objective Columbia River Regulation System in northwestern United States as an example to understand their effects on not only regulated flow but also reservoir storage and fraction of the demand that is met. Numerical experiments are designed to test new generic operating rules that combine storage and releases targets for multi-purpose reservoirs and to compare the use of reservoir usage priorities, withdrawals vs. consumptive demand, as well as natural vs. regulated mean flow for calibrating operating rules. Overall the best performing implementation is the use of the combined priorities (flood control storage targets and irrigation release targets) operating rules calibrated with mean annual natural flow and mean monthly withdrawals. The challenge of not accounting for groundwater withdrawals, or on the contrary, assuming that all remaining demand is met through groundwater extractions, is discussed.

Voisin, Nathalie; Li, Hongyi; Ward, Duane L.; Huang, Maoyi; Wigmosta, Mark S.; Leung, Lai-Yung R.

2013-09-30T23:59:59.000Z

338

Ecosystem feedbacks to climate change in California: Development, testing, and analysis using a coupled regional atmosphere and land-surface model (WRF3-CLM3.5)  

SciTech Connect (OSTI)

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

339

ModelingAtmosphericChemistryand Transport with Dynamic Adaptive Resolution  

E-Print Network [OSTI]

pollution has important implications for urban and regional air quality, for human health, and for climate avenues. Advantages and shortcomings of the present approach are also discussed. Keywords: air pollution be an important source of errors in CTMs. In air pollution simulations large spatial gradients of tracer

Sandu, Adrian

340

Dynamic Inversion for Hydrological Process Monitoring with Electrical Resistance Tomography Under Model Uncertainty  

SciTech Connect (OSTI)

We propose an approach for imaging the dynamics of complex hydrological processes. The evolution of electrically conductive fluids in porous media is imaged using time-lapse electrical resistance tomography. The related dynamic inversion problem is solved using Bayesian filtering techniques, that is, it is formulated as a sequential state estimation problem in which the target is an evolving posterior probability density of the system state. The dynamical inversion framework is based on the state space representation of the system, which involves the construction of a stochastic evolution model and an observation model. The observation model used in this paper consists of the complete electrode model for ERT, with Archie's law relating saturations to electrical conductivity. The evolution model is an approximate model for simulating flow through partially saturated porous media. Unavoidable modeling and approximation errors in both the observation and evolution models are considered by computing approximate statistics for these errors. These models are then included in the construction of the posterior probability density of the estimated system state. This approximation error method allows the use of approximate - and therefore computationally efficient - observation and evolution models in the Bayesian filtering. We consider a synthetic example and show that the incorporation of an explicit model for the model uncertainties in the state space representation can yield better estimates than a frame-by-frame imaging approach.

Lehikoinen, A.; Huttunen, J.M.J.; Finsterle, S.; Kowalsky, M.B.; Kaipio, J.P.

2009-08-01T23:59:59.000Z

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341

Dynamical System Approach to Cosmological Models with a Varying Speed of Light  

E-Print Network [OSTI]

Methods of dynamical systems have been used to study homogeneous and isotropic cosmological models with a varying speed of light (VSL). We propose two methods of reduction of dynamics to the form of planar Hamiltonian dynamical systems for models with a time dependent equation of state. The solutions are analyzed on two-dimensional phase space in the variables $(x, \\dot{x})$ where $x$ is a function of a scale factor $a$. Then we show how the horizon problem may be solved on some evolutional paths. It is shown that the models with negative curvature overcome the horizon and flatness problems. The presented method of reduction can be adopted to the analysis of dynamics of the universe with the general form of the equation of state $p=\\gamma(a)\\epsilon$. This is demonstrated using as an example the dynamics of VSL models filled with a non-interacting fluid. We demonstrate a new type of evolution near the initial singularity caused by a varying speed of light. The singularity-free oscillating universes are also admitted for positive cosmological constant. We consider a quantum VSL FRW closed model with radiation and show that the highest tunnelling rate occurs for a constant velocity of light if $c(a) \\propto a^n$ and $-1 < n \\le 0$. It is also proved that the considered class of models is structurally unstable for the case of $n < 0$.

Marek Szydlowski; Adam Krawiec

2002-12-16T23:59:59.000Z

342

Dynamic cone beam CT angiography of carotid and cerebral arteries using canine model  

SciTech Connect (OSTI)

Purpose: This research is designed to develop and evaluate a flat-panel detector-based dynamic cone beam CT system for dynamic angiography imaging, which is able to provide both dynamic functional information and dynamic anatomic information from one multirevolution cone beam CT scan. Methods: A dynamic cone beam CT scan acquired projections over four revolutions within a time window of 40 s after contrast agent injection through a femoral vein to cover the entire wash-in and wash-out phases. A dynamic cone beam CT reconstruction algorithm was utilized and a novel recovery method was developed to correct the time-enhancement curve of contrast flow. From the same data set, both projection-based subtraction and reconstruction-based subtraction approaches were utilized and compared to remove the background tissues and visualize the 3D vascular structure to provide the dynamic anatomic information. Results: Through computer simulations, the new recovery algorithm for dynamic time-enhancement curves was optimized and showed excellent accuracy to recover the actual contrast flow. Canine model experiments also indicated that the recovered time-enhancement curves from dynamic cone beam CT imaging agreed well with that of an IV-digital subtraction angiography (DSA) study. The dynamic vascular structures reconstructed using both projection-based subtraction and reconstruction-based subtraction were almost identical as the differences between them were comparable to the background noise level. At the enhancement peak, all the major carotid and cerebral arteries and the Circle of Willis could be clearly observed. Conclusions: The proposed dynamic cone beam CT approach can accurately recover the actual contrast flow, and dynamic anatomic imaging can be obtained with high isotropic 3D resolution. This approach is promising for diagnosis and treatment planning of vascular diseases and strokes.

Cai Weixing; Zhao Binghui; Conover, David; Liu Jiangkun; Ning Ruola [Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States); Department of Radiology, Shanghai 6th People's Hospital, 600 Yishan Road, Xuhui, Shanghai (China); Koning Corporation, Lennox Tech Enterprise Center, 150 Lucius Gordon Drive Suite 112, West Henrietta, New York 14586 (United States); Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States); Department of Imaging Sciences, University of Rochester, 601 Elmwood Avenue, Rochester, New York 14642 (United States) and Koning Corporation, Lennox Tech Enterprise Center, 150 Lucius Gordon Drive Suite 112, West Henrietta, New York 14586 (United States)

2012-01-15T23:59:59.000Z

343

Mathematical modeling of irreversible dynamic deformation, micro- and macrofracture of materials and structures  

National Nuclear Security Administration (NNSA)

7: Material Phase Transition, Modeling, and Others 7: Material Phase Transition, Modeling, and Others Mathematical Modeling of Irreversible Dynamic Deformation, Micro- and Macrofracture of Materials and Structures P. P. Zakharov and A. B. Kiselev All-Russia Research Institute of Automatics, Moscow 125412, Russia Thermomechanical processes, which proceed in deformable solids under intensive dynamic loading, consist of mechanical, thermal and structural ones, which correlate themselves. The structural processes involve the formation, motion and interaction of defects in metallic crystals, phase transitions, the breaking of bonds between molecules in polymers, the accumulation of microstructural damages (pores, cracks), etc. Irreversible deformations, zones of adiabatic shear and microfractures are caused by these

344

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

345

A. Ford and H. Flynn: Statistical Screening of Models 273 Statistical screening of system dynamics  

E-Print Network [OSTI]

in the information spectrum in Figure 1. Hard sources include physical laws and the results of controlled experimentsA. Ford and H. Flynn: Statistical Screening of Models 273 Statistical screening of system dynamics models Andrew Forda * and Hilary Flynnb Abstract This paper describes a pragmatic method of searching

Ford, Andrew

346

Modeling a Continuous Dynamic Task Wayne D. Gray, Michael J. Schoelles, & Wai-Tat Fu  

E-Print Network [OSTI]

Modeling a Continuous Dynamic Task Wayne D. Gray, Michael J. Schoelles, & Wai-Tat Fu Human Factors in several ways. Modeling the impact of one such difference raised theoretical issues in motor movement and attention. For motor movement, the issue concerned the functional shape and size of a target

Gray, Wayne

347

A simple Markov model of sodium channels with a dynamic threshold  

Science Journals Connector (OSTI)

Characteristics of action potential generation are important to understanding brain functioning and, thus, must be understood and modeled. It is still an open question what model can describe concurrently the phenomena of sharp spike shape, the spike ... Keywords: Conductance-based neurons, Divisive effect, Dynamic patch-clamp, Sodium channels, Spike shape, Spike threshold

A. V. Chizhov; E. Yu. Smirnova; K. Kh. Kim; A. V. Zaitsev

2014-08-01T23:59:59.000Z

348

FLUID DYNAMICAL AND MODELING ISSUES OF CHEMICAL FLOODING FOR ENHANCED OIL RECOVERY  

E-Print Network [OSTI]

FLUID DYNAMICAL AND MODELING ISSUES OF CHEMICAL FLOODING FOR ENHANCED OIL RECOVERY Prabir Daripa. Relevance of this HS model based result to EOR is established by performing direct numerical simulations of fully developed tertiary displacement in porous media. Results of direct numer- ical simulation

Daripa, Prabir

349

A model of sediment resuspension and transport dynamics in southern Lake Michigan  

E-Print Network [OSTI]

A model of sediment resuspension and transport dynamics in southern Lake Michigan Jing Lou-three-dimensional suspended sediment transport model was developed and generalized to include combined wave-current effects to study bottom sediment resuspension and transport in southern Lake Michigan. The results from a three

350

Liquid Water Dynamics in a Model Polymer Electrolyte Fuel Cell Flow Channel  

E-Print Network [OSTI]

Liquid Water Dynamics in a Model Polymer Electrolyte Fuel Cell Flow Channel by Chris Miller in a Model Polymer Electrolyte Fuel Cell Flow Channel by Chris Miller Bachelors of Engineering, University in a polymer electrolyte fuel cell is a critical issue in ensuring high cell performance. The water production

Victoria, University of

351

Modeling of quasistatic and dynamic load responses of filled viscoelastic materials  

E-Print Network [OSTI]

are typically used for static finite element analysis (see [9]). The CRSC/Lord team worked, both theoreticallyModeling of quasi­static and dynamic load responses of filled viscoelastic materials H.T. Banks factors to the complications arising in the process of formulating models. Damping is highly complex

352

Transient dynamics and food–web complexity in the Lotka–Volterra cascade model  

Science Journals Connector (OSTI)

...research-article Transient dynamics and food-web complexity in the Lotka-Volterra cascade...behaviour near equilibrium of model food webs correlate with their short-term transient...Lotka-Volterra cascade model of food webs provide the first evidence to answer this...

2001-01-01T23:59:59.000Z

353

Towards a Formal Semantics for a Structurally Dynamic Noncausal Modelling Language  

E-Print Network [OSTI]

, many of these languages are referred to as object-oriented mod- elling languages. Modelica [23] is oneTowards a Formal Semantics for a Structurally Dynamic Noncausal Modelling Language John Capper, UK nhn@cs.nott.ac.uk Abstract Modelling and simulation languages are evolving rapidly to sup- port

Nilsson, Henrik

354

Integrating Models and Simulations of Continuous Dynamics into SysML  

E-Print Network [OSTI]

and the corresponding Modelica models; and the integration of simulation experiments with other SysML constructsIntegrating Models and Simulations of Continuous Dynamics into SysML Thomas Johnson1 Christiaan J.J. Paredis1 Roger Burkhart2 1 Systems Realization Laboratory The G. W. Woodruff School of Mechanical

355

Offshore floating vertical axis wind turbines, dynamics modelling state of the art. Part III: Hydrodynamics and coupled modelling approaches  

Science Journals Connector (OSTI)

Abstract The need to further exploit offshore wind resources has pushed offshore wind farms into deeper waters, requiring the use of floating support structures to be economically sustainable. The use of conventional wind turbines may not continue to be the optimal design for floating applications. Therefore it is important to assess other alternative configurations in this context. Vertical axis wind turbines (VAWTs) are one promising configuration, and it is important to first understand the coupled and relatively complex dynamics of floating \\{VAWTs\\} to assess the technical feasibility. As part of this task, a series of articles have been developed to present a comprehensive literature review covering the various areas of engineering expertise required to understand the coupled dynamics involved in floating VAWTs. This third article focuses on approaches to develop an efficient coupled model of dynamics (considering aerodynamics, hydrodynamics, structural and mooring line dynamics, and control dynamics) for floating VAWTs, as well as suitable ‘semi-analytical’ hydrodynamic models for this type of coupled dynamics models. Emphasis is also placed on utilising computationally efficient models and programming strategies. A comparison of the various forces acting on a floating VAWT with the three main floating support structure (spar, semi-submersible and tension-leg-platform) is also presented to highlight the relative dominant forces and hence importance of model accuracy representing these forces. Lastly a concise summary covering this series of articles is presented to give the reader an overview of this interdisciplinary research area. This article has been written both for researchers new to this research area, outlining underlying theory whilst providing a comprehensive review of the latest work, and for experts in this area, providing a comprehensive list of the relevant references where the details of modelling approaches may be found.

Michael Borg; Maurizio Collu

2014-01-01T23:59:59.000Z

356

Dynamic Models for Wind Turbines and Wind Power Plants  

SciTech Connect (OSTI)

The primary objective of this report was to develop universal manufacturer-independent wind turbine and wind power plant models that can be shared, used, and improved without any restrictions by project developers, manufacturers, and engineers. Manufacturer-specific models of wind turbines are favored for use in wind power interconnection studies. While they are detailed and accurate, their usages are limited to the terms of the non-disclosure agreement, thus stifling model sharing. The primary objective of the work proposed is to develop universal manufacturer-independent wind power plant models that can be shared, used, and improved without any restrictions by project developers, manufacturers, and engineers. Each of these models includes representations of general turbine aerodynamics, the mechanical drive-train, and the electrical characteristics of the generator and converter, as well as the control systems typically used. To determine how realistic model performance is, the performance of one of the models (doubly-fed induction generator model) has been validated using real-world wind power plant data. This work also documents selected applications of these models.

Singh, M.; Santoso, S.

2011-10-01T23:59:59.000Z

357

Patch Occupancy Models of Metapopulation Dynamics: Ef?cient ...  

E-Print Network [OSTI]

with spatial data on patch occupancyv The latter data are more readily available. ... and it can be adapted to any stochastic patch occupancy model of ...

358

Transmission Dynamics of an Influenza Model with Vaccination and ...  

E-Print Network [OSTI]

Jun 30, 2009 ... promised if drug-resistant strains arise. In this paper, we develop a mathematical model to explore the impact of vaccination and antiviral ...

2010-01-15T23:59:59.000Z

359

Dynamic model of anisotropic x-ray refraction  

Science Journals Connector (OSTI)

General mechanisms of anisotropic x-ray refraction at the resonance energy are investigated on the basis of dynamic-scattering theory. The deductions show that x rays within the crystals that have anisotropic susceptibility are completely polarized and have two elliptical polarization states. Analytical expressions of the elliptical axes, refractive indices, and absorption coefficients for these two types of polarized waves are obtained in terms of the anisotropic components of the susceptibility tensor. Anisotropic birefringence and dichroism effects associated with the polarization properties of the x-ray waves are also illustrated theoretically.

X. R. Huang, Yong Li, W. J. Liu, and S. S. Jiang

1997-11-01T23:59:59.000Z

360

Relativistic Dynamical Collapse Model for a Scalar Field  

E-Print Network [OSTI]

A natural generalization of the CSL (Continuous Spontaneous Localization) theory of dynamical collapse is applied to a relativistic quantum scalar field $\\phi({\\bf x},t)$. It is shown that the modified Schr\\"odinger equation is relativistically invariant, that the probabilities associated to all possible values of the classical scalar random field $w({\\bf x},t)$ (which determines the eventual state of collapse) add up to 1, that there is no energy production out of the vacuum and, in the limit of large time, the collapse is toward eigenstates of $\\phi({\\bf x},0)$.

Philip Pearle

2014-04-26T23:59:59.000Z

Note: This page contains sample records for the topic "regional dynamics model" 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

Theoretical modeling of propagation of magneto-acoustic waves in magnetic regions below sunspots  

E-Print Network [OSTI]

We use 2D numerical simulations and eikonal approximation, to study properties of MHD waves traveling below the solar surface through the magnetic structure of sunspots. We consider a series of magnetostatic models of sunspots of different magnetic field strengths, from 10 Mm below the photosphere to the low chromosphere. The purpose of these studies is to quantify the effect of the magnetic field on local helioseismology measurements by modeling waves excited by sub-photospheric sources. Time-distance propagation diagrams and wave travel times are calculated for models of various field strength and compared to the non-magnetic case. The results clearly indicate that the observed time-distance helioseismology signals in sunspot regions correspond to fast MHD waves. The slow MHD waves form a distinctly different pattern in the time-distance diagram, which has not been detected in observations. The numerical results are in good agreement with the solution in the short-wavelength (eikonal) approximation, providing its validation. The frequency dependence of the travel times is in a good qualitative agreement with observations.

E. Khomenko; A. Kosovichev; M. Collados; K. Parchevsky; V. Olshevsky

2008-09-01T23:59:59.000Z

362

Theoretical Modeling of Propagation of Magnetoacoustic Waves in Magnetic Regions Below Sunspots  

Science Journals Connector (OSTI)

We use two-dimensional numerical simulations and eikonal approximation to study properties of magnetohydrodynamic (MHD) waves traveling below the solar surface through the magnetic structure of sunspots. We consider a series of magnetostatic models of sunspots of different magnetic field strengths, from 10 Mm below the photosphere to the low chromosphere. The purpose of these studies is to quantify the effect of the magnetic field on local helioseismology measurements by modeling waves excited by subphotospheric sources. Time-distance propagation diagrams and wave travel times are calculated for models of various field strengths and compared to the nonmagnetic case. The results clearly indicate that the observed time-distance helioseismology signals in sunspot regions correspond to fast MHD waves. The slow MHD waves form a distinctly different pattern in the time-distance diagram, which has not been detected in observations. The numerical results are in good agreement with the solution in the short-wavelength (eikonal) approximation, providing its validation. The frequency dependence of the travel times is in good qualitative agreement with observations.

E. Khomenko; A. Kosovichev; M. Collados; K. Parchevsky; V. Olshevsky

2009-01-01T23:59:59.000Z

363

Two-stage fuzzy-stochastic robust programming: a hybrid model for regional air quality management  

SciTech Connect (OSTI)

In this study, a hybrid two-stage fuzzy-stochastic robust programming (TFSRP) model is developed and applied to the planning of an air-quality management system. As an extension of existing fuzzy-robust programming and two stage stochastic programming methods, the TFSRP can explicitly address complexities and uncertainties of the study system without unrealistic simplifications. Uncertain parameters can be expressed as probability density and/or fuzzy membership functions, such that robustness of the optimization efforts can be enhanced. Moreover, economic penalties as corrective measures against any infeasibilities arising from the uncertainties are taken into account. This method can, thus, provide a linkage to predefined policies determined by authorities that have to be respected when a modeling effort is undertaken. In its solution algorithm, the fuzzy decision space can be delimited through specification of the uncertainties using dimensional enlargement of the original fuzzy constraints. The developed model is applied to a case study of regional air quality management at two coal-fired power plants considered as major sulfur dioxide emission sources. The results indicate that reasonable solutions have been obtained. The solutions can be used for further generating pollution-mitigation alternatives with minimized system costs and for providing a more solid support for sound environmental decisions. 61 refs., 7 figs., 6 tabs.

Yongping Li; Guo H. Huang; Amornvadee Veawab; Xianghui Nie; Lei Liu [University of Regina, Regina, SK (Canada). Environmental Systems Engineering Program

2006-08-15T23:59:59.000Z

364

Dynamic Modeling and Control Studies of a Two-Stage Bubbling Fluidized Bed Adsorber-Reactor for Solid-Sorbent CO{sub 2} Capture  

SciTech Connect (OSTI)

A one-dimensional, non-isothermal, pressure-driven dynamic model has been developed for a two-stage bubbling fluidized bed (BFB) adsorber-reactor for solid-sorbent carbon dioxide (CO{sub 2}) capture using Aspen Custom Modeler® (ACM). The BFB model for the flow of gas through a continuous phase of downward moving solids considers three regions: emulsion, bubble, and cloud-wake. Both the upper and lower reactor stages are of overflow-type configuration, i.e., the solids leave from the top of each stage. In addition, dynamic models have been developed for the downcomer that transfers solids between the stages and the exit hopper that removes solids from the bottom of the bed. The models of all auxiliary equipment such as valves and gas distributor have been integrated with the main model of the two-stage adsorber reactor. Using the developed dynamic model, the transient responses of various process variables such as CO{sub 2} capture rate and flue gas outlet temperatures have been studied by simulating typical disturbances such as change in the temperature, flowrate, and composition of the incoming flue gas from pulverized coal-fired power plants. In control studies, the performance of a proportional-integral-derivative (PID) controller, feedback-augmented feedforward controller, and linear model predictive controller (LMPC) are evaluated for maintaining the overall CO{sub 2} capture rate at a desired level in the face of typical disturbances.

Modekurti, Srinivasarao; Bhattacharyya, Debangsu; Zitney, Stephen E.

2013-07-31T23:59:59.000Z

365

Analysis of Permafrost Thermal Dynamics and Response to Climate Change in the CMIP5 Earth System Models  

Science Journals Connector (OSTI)

The authors analyze global climate model predictions of soil temperature [from the Coupled Model Intercomparison Project phase 5 (CMIP5) database] to assess the models’ representation of current-climate soil thermal dynamics and their predictions ...

Charles D. Koven; William J. Riley; Alex Stern

2013-03-01T23:59:59.000Z

366

Implementation of a torque and a collective pitch controller in a wind turbine simulator to characterize the dynamics at three control regions  

Science Journals Connector (OSTI)

Abstract As the capacity of wind turbines has increased, the loads on crucial components such as a gearbox, a generator, and blades are significantly increasing. An intelligent online monitoring system is indispensable to protect the excessive load on core components and manage a wind farm efficiently. In order to verify new online monitoring and diagnostic methods for such a monitoring system in advance, a wind turbine simulator is essential. For this purpose, we developed a simulator that has similar dynamics to an actual 3 MW wind turbine, and is thereby able to acquire a state of operation that closely resembles that of the 3 MW wind turbine under a variety of wind conditions. This paper describes the implementation of a torque and a collective pitch controller, which is used for a new type of simulator with the intention of exploiting online monitoring and diagnostic methods. The torque and the collective pitch controllers were developed to facilitate variable speed-variable pitch control strategies in the wind turbine simulator. Experiments demonstrated that three control regions were successfully deployed on the simulator, and thereby the simulator was operated at all control regions in a stable and accurate manner. Moreover, the strain and vibration measured from the blade and the gearbox showed different trends at three control regions. Therefore, a new type of simulator is an effective means to develop diagnostic and prognostic algorithms as well as online monitoring methods reflecting the dependency of dynamic characteristics on the control regions.

Ki-Yong Oh; Joon-Young Park; Jun-Shin Lee; JaeKyung Lee

2014-01-01T23:59:59.000Z

367

Dynamical instabilities in density-dependent hadronic relativistic models  

SciTech Connect (OSTI)

Unstable modes in asymmetric nuclear matter (ANM) at subsaturation densities are studied in the framework of relativistic mean-field density-dependent hadron models. The size of the instabilities that drive the system are calculated and a comparison with results obtained within the nonlinear Walecka model is presented. The distillation and antidistillation effects are discussed.

Santos, A. M.; Brito, L.; Providencia, C. [Centro de Fisica Teorica, Department of Physics, University of Coimbra, P-3004-516 Coimbra (Portugal)

2008-04-15T23:59:59.000Z

368

Theoretical modeling of propagation of magneto-acoustic waves in magnetic regions below sunspots  

E-Print Network [OSTI]

We use 2D numerical simulations and eikonal approximation to study properties of magneto-acoustic gravity waves traveling below the solar surface through the magnetic structure of sunspots. We consider a series of magnetostatic models of sunspots of different magnetic field strengths, from the deep interior to the chromosphere. The purpose of these studies is to quantify the effect of the magnetic field on local helioseismology measurements. Waves are excited by a sub-photospheric source located in the region beta slightly larger than 1. Time-distance diagrams and travel times are calculated for various frequency intervals and compared to the non-magnetic case. The results confirm that the observed time-distance helioseismology signals in sunspot regions correspond to fast MHD waves. The slow MHD waves form a distinctly different pattern in the time-distance diagram, which has not been detected in observations. The numerical results are in good agreement with the solution in the short-wavelength (eikonal) app...

Khomenko, E; Collados, M; Parchevsky, K; Olshevsky, V

2008-01-01T23:59:59.000Z

369

Dynamic (G2) Model Design Document, 24590-WTP-MDD-PR-01-002, Rev. 12  

SciTech Connect (OSTI)

The Hanford Tank Waste Treatment and Immobilization Plant (WTP) Statement of Work (Department of Energy Contract DE-AC27-01RV14136, Section C) requires the contractor to develop and use process models for flowsheet analyses and pre-operational planning assessments. The Dynamic (G2) Flowsheet is a discrete-time process model that enables the project to evaluate impacts to throughput from eventdriven activities such as pumping, sampling, storage, recycle, separation, and chemical reactions. The model is developed by the Process Engineering (PE) department, and is based on the Flowsheet Bases, Assumptions, and Requirements Document (24590-WTP-RPT-PT-02-005), commonly called the BARD. The terminologies of Dynamic (G2) Flowsheet and Dynamic (G2) Model are interchangeable in this document. The foundation of this model is a dynamic material balance governed by prescribed initial conditions, boundary conditions, and operating logic. The dynamic material balance is achieved by tracking the storage and material flows within the plant as time increments. The initial conditions include a feed vector that represents the waste compositions and delivery sequence of the Tank Farm batches, and volumes and concentrations of solutions in process equipment before startup. The boundary conditions are the physical limits of the flowsheet design, such as piping, volumes, flowrates, operation efficiencies, and physical and chemical environments that impact separations, phase equilibriums, and reaction extents. The operating logic represents the rules and strategies of running the plant.

Deng, Yueying; Kruger, Albert A.

2013-12-16T23:59:59.000Z

370

Journal of the Meteorological Society of Japan, Vol. 82, No. 6, pp. 1599--1628, 2004 1599 Regional Climate Modeling: Progress, Challenges, and Prospects  

E-Print Network [OSTI]

, and development of regional earth system models. It is believed that with the demonstrated credibility of RCMs

Wang, Yuqing

371

Dynamic modeling and transient studies of a solid-sorbent adsorber for CO{sub 2} capture  

SciTech Connect (OSTI)

The U.S. Department of Energy’s Carbon Capture Simulation Initiative (CCSI) is dedicated to accelerating the commercialization of carbon capture technologies from discovery to development, demonstration, and ultimately the widespread deployment to hundreds of power plants. In this multi-lab initiative in partnership with academic and industrial institutions, the National Energy Technology Laboratory (NETL) leads the development of a multi-scale modeling and simulation toolset for rapid evaluation and deployment of carbon capture systems. One element of the CCSI is focused on optimizing the operation and control of carbon capture systems since this can have a significant impact on the extent and the rate at which commercial-scale capture processes will be scaled-up, deployed, and used in the years to come. Capture processes must be capable of operating over a wide range of transient events, malfunctions, and disturbances, as well as under uncertainties. As part of this work, dynamic simulation and control models, methods, and tools are being developed for CO{sub 2} capture and compression processes and their integration with a baseline commercial-scale supercritical pulverized coal (SCPC) power plant. Solid-sorbent-based post-combustion capture technology was chosen as the first industry challenge problem for CCSI because significant work remains to define and optimize the reactors and processes needed for successful sorbent capture systems. Sorbents offer an advantage because they can reduce the regeneration energy associated with CO{sub 2} capture, thus reducing the parasitic load. In view of this, the current paper focuses on development of a dynamic model of a solid-sorbent CO{sub 2} adsorber-reactor and an analysis of its transient performance with respect to several typical process disturbances. A one-dimensional, non-isothermal, pressure-driven dynamic model of a two-stage bubbling fluidized bed (BFB) adsorber-reactor is developed in Aspen Custom Modeler (ACM). The BFB stages are of overflow-type configuration where the solids leave the stage by flowing over the overflow-weir. Each bed is divided into three regions, namely emulsion, bubble, and cloud-wake regions. In all three regions, the model considers mass and energy balances. Along with the models of the BFB stages, models of other associated hardware are developed and integrated in a single flowsheet. A valid pressure-flow network is developed and a lower-level control system is designed so that the overall CO{sub 2} capture can be maintained at a desired level in face of the typical disturbances. The dynamic model is used for studying the transient responses of a number of important process variables as a result of the disturbances that are typical of post-combustion CO{sub 2} capture processes.

Modekurti, Srinivasarao [WVU; Bhattacharyya, Debangsu [WVU; Zitney, Stephen E. [U.S. DOE

2012-01-01T23:59:59.000Z

372

Polarimetric modeling of corotating interaction regions (CIRs) threading massive-star winds  

E-Print Network [OSTI]

Massive star winds are complex radiation-hydrodynamic (sometimes magnetohydrodynamic) outflows that are propelled by their enormously strong luminosities. The winds are often found to be structured and variable, but can also display periodic or quasi-periodic behavior in a variety of wind diagnostics. The regular variations observed in putatively single stars, especially in UV wind lines, have often been attributed to corotating interaction regions (CIRs) like those seen in the solar wind. We present light curves for variable polarization from winds with CIR structures. We develop a model for a time-independent CIR based on a kinematical description. Assuming optically thin electron scattering, we explore the range of polarimetric light curves that result as the curvature, latitude, and number of CIRs are varied. We find that a diverse array of variable polarizations result from an exploration of cases. The net polarization from an unresolved source is weighted more toward the inner radii of the wind. Given t...

Ignace, R; Proulx-Giraldeau, F

2015-01-01T23:59:59.000Z

373

Modeling dynamic conditional correlations in WTI oil forward and futures returns  

Science Journals Connector (OSTI)

This paper estimates the dynamic conditional correlations in the daily returns on West Texas Intermediate (WTI) oil forward and futures prices from 3 January 1985 to 16 January 2004, using recently developed multivariate conditional volatility models. We find that the dynamic conditional correlations can vary dramatically, being negative in four of ten cases and being close to zero in another five cases. Only in the case of the dynamic volatilities of the three-month and six-month futures returns is the range of variation relatively narrow, namely (0.832, 0.996).

Alessandro Lanza; Matteo Manera; Michael McAleer

2006-01-01T23:59:59.000Z

374

Dynamic modeling of an integrated air-to-air heat pump using Modelica  

Science Journals Connector (OSTI)

Heat pump systems have gained significant market shares in Europe recently. The control strategy is an asset for the efficient operation of these thermodynamic systems; especially with compact integrated components. The predictive control, which allows fast system stabilization, is based on the description of the system physical behavior. Thus, dynamic modeling is needed for the development of such control. The model has to represent the system response to usual external perturbations met during current operation such as the variation of air temperature and air mass flow rate. The aim of this paper is to present a dynamic model of a thermodynamic system developed in the Dymola environment, which is an object-oriented modeling environment. The heat-pump components are created separately as individual objects, and then connected to form the system. The model of each component is described and the responses to different perturbations are detailed. Simulation results are compared to test results in order to validate the model.

S. Mortada; A. Zoughaib; D. Clodic; C. Arzano-Daurelle

2012-01-01T23:59:59.000Z

375

A hybrid dynamic and fuzzy time series model for mid-term power load forecasting  

Science Journals Connector (OSTI)

Abstract A new hybrid model for forecasting the electric power load several months ahead is proposed. To allow for distinct responses from individual load sectors, this hybrid model, which combines dynamic (i.e., air temperature dependency of power load) and fuzzy time series approaches, is applied separately to the household, public, service, and industrial sectors. The hybrid model is tested using actual load data from the Seoul metropolitan area, and its predictions are compared with those from two typical dynamic models. Our investigation shows that, in the case of four-month forecasting, the proposed model gives the actual monthly power load of every sector with only less than 3% absolute error and satisfactory reduction of forecasting errors compared to other models from previous studies.

Woo-Joo Lee; Jinkyu Hong

2015-01-01T23:59:59.000Z

376

Dynamical phase space from a SO(d,d) matrix model  

E-Print Network [OSTI]

It is shown that a matrix model with SO($d,d$) global symmetry is derived from a generalized Yang-Mills theory on the standard Courant algebroid. This model keeps all the positive features of the well-studied type IIB matrix model, and it has many additional welcome properties. We show that it does not only capture the dynamics of spacetime, but it should be associated with the dynamics of phase space. This is supported by a large set of classical solutions of its equations of motion, which corresponds to phase spaces of noncommutative curved manifolds and points to a new mechanism of emergent gravity. The model possesses an additional symmetry that exchanges positions and momenta, in analogy to quantum mechanics. It is argued that the emergence of phase space in the model is an essential feature for the investigation of the precise relation of matrix models to string theory and quantum gravity.

Athanasios Chatzistavrakidis

2014-07-25T23:59:59.000Z

377

Dynamic modeling of a single-stage downward firing, entrained flow gasifier  

SciTech Connect (OSTI)

The gasifier is the heart of the integrated gasification combined cycle (IGCC), a technology that has emerged as an attractive alternative to conventional coal-fired power plant technology due to its higher efficiency and cleaner environmental performance especially with the option of CO{sub 2} capture and sequestration. Understanding the optimal performance of the gasifier is therefore paramount for the efficient operation of IGCC power plants. Numerous gasifier models of varying complexity have been developed to study the various aspects of gasifier performance. These range from simple one-dimensional (1D) process-type models to rigorous higher order 2-3D models based on computational fluid dynamics (CFD). Whereas high-fidelity CFD models can accurately predict most key aspects of gasifier performance, they are computationally expensive and typically take hours to days to execute on high-performance computers. Therefore, faster 1D partial differential equation (PDE)-based models are required for use in dynamic simulation studies, control system analysis, and training applications. A number of 1D gasifier models can be found in the literature, but most are steady-state models that have limited application in the practical operation of the gasifier. As a result, 1D PDE-based dynamic models are needed to further study and predict gasifier performance under a wide variety of process conditions and disturbances. In the current study, a 1D transient model of a single-stage downward-fired GE/Texaco-type entrained-flow gasifier has been developed. The model comprises mass, momentum and energy balances for the gas and solid phases. The model considers the initial gasification processes of water evaporation and coal devolatilization. In addition, the key heterogeneous and homogeneous chemical reactions have been modeled. The resulting time-dependent PDE model is solved using the well-known method of lines approach in Aspen Custom Modeler®, whereby the PDEs in the spatial domain are discretized and the resulting differential algebraic equations (DAEs) are then integrated over time using a dynamic integrator. The dynamic response results of the gasifier performance parameters to certain disturbances commonly encountered during practical operation are presented. These disturbances include ramp and step changes to input variables such as coal flow rate, oxygen-to-coal ratio and water-to-coal ratio among others. Comparison of model predictions to available dynamic data will also be discussed.

Kasule, J., Turton, R., Bhattacharyya, D., Zitney, S.

2012-01-01T23:59:59.000Z

378

Dynamic  

Office of Legacy Management (LM)

Dynamic Dynamic , and Static , Res.ponse of the Government Oil Shale Mine at ' , . , Rifle, Colorado, to the Rulison Event. , . ; . . DISCLAIMER Portions of this document may be illegible in electronic image products. Images are produced from the best available original document. p ( y c - - a 2-1 0 -4- REPORT AT (29-2) 914 USBM 1 0 0 1 UNITED STATES DEPARTMENT O F THE I NTERIOR BUREAU OF MINES e s.09 P. L. R U S S E L L RESEARCH D l RECTOR Februory 2, lB7O DYNAMIC AND STATIC RESPONSE 'OF THE GOVERNMENT OIL SHALE MINE A T RIFLE, COLORADO, T O THE, RULISON EVENT ORDER FROM CFSTl A S ~ B ~ &J C / This page intentionally left blank CONTENTS Page . . . . . . . . . . . . . . . . . . . . . . . . . H i s t o r i c . a l Des c r i p t i o n 1 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Summary 2 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Introduction 3

379

Development of microbial-enzyme-mediated decomposition model parameters through steady-state and dynamic analyses  

SciTech Connect (OSTI)

We developed a Microbial-ENzyme-mediated Decomposition (MEND) model, based on the Michaelis-Menten kinetics, that describes the dynamics of physically defined pools of soil organic matter (SOC). These include particulate, mineral-associated, dissolved organic matter (POC, MOC, and DOC, respectively), microbial biomass, and associated exoenzymes. The ranges and/or distributions of parameters were determined by both analytical steady-state and dynamic analyses with SOC data from the literature. We used an improved multi-objective parameter sensitivity analysis (MOPSA) to identify the most important parameters for the full model: maintenance of microbial biomass, turnover and synthesis of enzymes, and carbon use efficiency (CUE). The model predicted an increase of 2 C (baseline temperature =12 C) caused the pools of POC-Cellulose, MOC, and total SOC to increase with dynamic CUE and decrease with constant CUE, as indicated by the 50% confidence intervals. Regardless of dynamic or constant CUE, the pool sizes of POC, MOC, and total SOC varied from 8% to 8% under +2 C. The scenario analysis using a single parameter set indicates that higher temperature with dynamic CUE might result in greater net increases in both POC-Cellulose and MOC pools. Different dynamics of various SOC pools reflected the catalytic functions of specific enzymes targeting specific substrates and the interactions between microbes, enzymes, and SOC. With the feasible parameter values estimated in this study, models incorporating fundamental principles of microbial-enzyme dynamics can lead to simulation results qualitatively different from traditional models with fast/slow/passive pools.

Wang, Gangsheng [ORNL; Post, Wilfred M [ORNL; Mayes, Melanie [ORNL

2013-01-01T23:59:59.000Z

380

Investigating the dynamic behavior of biochemical networks using model families  

Science Journals Connector (OSTI)

......computing technology, a high performance computing environment is achieved...the models, the usage of high performance computing is mandatory (see Section...development of MMT2 is high performance computing. On the other hand, MMT2......

Marc Daniel Haunschild; Bernd Freisleben; Ralf Takors; Wolfgang Wiechert

2005-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "regional dynamics model" 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

Tests of an Ensemble Kalman Filter for Mesoscale and Regional-Scale Data Assimilation. Part II: Imperfect Model Experiments  

E-Print Network [OSTI]

degraded). As in Part I, where the perfect model assumption was utilized, most analysis error reduction of significant model errors due to physical parameterizations by assimilating synthetic sounding and surfaceTests of an Ensemble Kalman Filter for Mesoscale and Regional-Scale Data Assimilation. Part II

Meng, Zhiyong

382

A computer-aided modelling analogue for lattice dynamics  

Science Journals Connector (OSTI)

A useful methodology to study lattice dynamics is presented in this paper. Our method is based on the analogous behaviour of electromagnetic waves in transmission lines. The parameters analysed include the optical and acoustical branches and the frequency gap. The electrical circuit is solved using commercial software (MicroCap ); therefore, our methodology would be easily implemented on different systems. Resumen. En este trabajo se presenta una metodología útil para estudiar dinámica de redes. Nuestro método se basa en el comportamiento análogo de las ondas electromagnéticas en las líneas de transmición. Los parámetros analizados incluyen las ramas óptica y acústica y el gap de frecuencia. El circuito eléctrico es resuelto utlizando un software comercial (MicroCap ); por lo que nuestra metodologiá puede ser fácilmente implementada en diferentes sistemas.

Daniel Vega; Sergio Vera; Alfredo Juan

1997-01-01T23:59:59.000Z

383

A LuGre Tire Friction Model with Exact Aggregate Dynamics Panagiotis Tsiotras, Efstathios Velenis and Michel Sorine  

E-Print Network [OSTI]

A LuGre Tire Friction Model with Exact Aggregate Dynamics Panagiotis Tsiotras, Efstathios Velenis and Michel Sorine Abstract-- The LuGre dynamic point contact friction model for the two-dimensional translation of a body on a surface has been used in the past to derive a model for the friction forces

Tsiotras, Panagiotis

384

Dynamic modelling of MSF plants for automatic control and simulation purposes: a survey  

Science Journals Connector (OSTI)

The successful development of a control system requires an appropriate definition of the control structure (i.e., selection of output, input and disturbance variables) and an efficient dynamical model on which the design, analysis and evaluation can be carried out. Thus, the confidence in the obtained results depends on the validity of the control structure and of the model used. For multistage flash (MSF) desalination processes, several dynamical models can be found in the literature. However, most of them are not suitable for analysis and control design purposes because they bring too many variables into play. The variables, which are sharing in the control system, normally constitute a reduced subset of the total variables that can be defined in the process. Moreover, a dynamical model suitable for control is simpler than the model derived from the physics of the underlying process. Hence, the selection of variables and the model building from the point of view of control design presents a compromise between the indispensable information contained in the model and the mathematical complexity proper of the design. In this paper, different models from the literature are analysed. Their advantages and drawbacks are described taking into account simulation and automatic control purposes. Moreover, a set of wished modelling facilities from the control engineer point of view is highlighted. Finally, a block-oriented library for Matlab/Simulink is presented, so that different plant configurations can be implemented as block diagram to simulate the system and to test control algorithms.

Adrian Gambler; Essameddin Badreddin

2004-01-01T23:59:59.000Z

385

Modeling and dynamic performance evaluation of target capture in robotic systems  

SciTech Connect (OSTI)

In this paper, a dynamic system consisting of a robot manipulator and a target is analyzed. The target is considered in a general way as a dynamic subsystem having finite mass and moments of inertia (e.g., a rigid body or a second robot). The situation investigated is when the robot establishes interaction with the target in such a way that it intercepts and captures a reference element of the target. The analysis of target capture is divided into three phases in terms of time: the precapture, free motion (finite motion); the transition from free to constrained motion in the vicinity of interception and capture (impulsive motion); and the postcapture, constrained motion (finite motion). The greatest attention is paid to the analysis of the phase of transition, the impulsive motion, and dynamics of the system. Based on the use of impulsive constraints and the Jourdainian formulation of analytical dynamics, a novel approach is proposed for the dynamic modeling of target capture by a robot manipulator. The proposed approach is suitable to handle both finite and impulsive motions in a common analytical framework. Based on the dynamic model developed and using a geometric representation of the system's dynamics, a detailed analysis and a performance evaluation framework are presented for the phase of transition. Both rigid and structurally flexible models of robots are considered. For the performance evaluation analyses, two main concepts are proposed and corresponding performance measures are derived. These tools may be used in the analysis, design, and control of time-varying robotic systems. The dynamic system of a three-link robot arm capturing a rigid body is used to illustrate the material presented.

Koevecses, J.; Cleghorn, W.L.; Fenton, R.G.

2000-04-01T23:59:59.000Z

386

Dynamic modeling of steam power cycles: Part II – Simulation of a small simple Rankine cycle system  

Science Journals Connector (OSTI)

This paper presents the second part of the work concerning the dynamic simulation of small steam cycle plants for power generation. The work is part of the preliminary study for a 600 kWe biomass fired steam power plant for which the complete open-loop, lumped parameter dynamic model of the steam cycle has been developed using the SimECS software described in Part I of this work. For these low-power plants, a dynamic simulation tool is especially useful because these systems must be designed to operate in transient mode for most of the time. The plant model presented here consists of the following components: feedwater pump, economizer, evaporator, superheater, impulse turbine, electrical generator and condenser. The primary heat source is modeled as a flue gas flow and no combustion models are incorporated yet to model the furnace. A description of the various components forming the complete steam cycle is given to illustrate the capabilities and modularity of the developed modeling technique. The model is first validated quantitatively against steady-state values obtained using a well known, reliable steady-state process modeling software. Subsequently, the dynamic validation is presented. Results can only be discussed based on the qualitative assessment of the observed trends because measurements are not available, being the plant in the preliminary design phase. The qualitative validation is based on four dynamic simulations involving three small step disturbances of different magnitude imposed on the pump rotational speed and on the flue gas mass flow and a single large ramp disturbance on the flue gas mass flow.

H. van Putten; P. Colonna

2007-01-01T23:59:59.000Z

387

Dynamic measurement and modeling of the Casimir force at the nanometer scale  

SciTech Connect (OSTI)

We present a dynamic method for measurement of the Casimir force with an atomic force microscope (AFM) with a conventional AFM tip. With this method, originally based on the phase of vibration of the AFM tip, we are able to verify the Casimir force at distances of nearly 6 nm with an AFM tip that has a radius of curvature of nearly 100 nm. Until now dynamic methods have been done using large metal spheres at greater distances. Also presented is a theoretical model based on the harmonic oscillator, including nonidealities. This model accurately predicts the experimental data.

Kohoutek, John; Wan, Ivy Yoke Leng; Mohseni, Hooman [Bio-Inspired Sensors and Optoelectronics Laboratory (BISOL), EECS, Northwestern University, 2145 Sheridan Rd., Evanston, Illinois 60208 (United States)

2010-02-08T23:59:59.000Z

388

Lurking Pathway Prediction And Pathway ODE Model Dynamic Analysis  

E-Print Network [OSTI]

regulated proteins in the transduction pro- cess. And by modeling the CCL2 pathway in MTB infected cells, J N K , cM Y C and P LC showed as the most significant modules. Hence, the drug treatments inhibit- ing J N K , cM Y C and P LC would effectively...

Zhang, Rengjing

2013-11-18T23:59:59.000Z

389

Isotope uptake dynamics in the Ostwald ripening model of recrystallization  

E-Print Network [OSTI]

The article is withdrawn since we decided not to publish it in the present form but to divide it in two parts. One of these parts concerns the mathematical aspects of Return Radius calculation and the rewritten article is already available arXiv:1201.4492 The second part will discuss the modelling of the Isotope Uptake and is still in preparation

Evgeny Lakshtanov; Leonid Lakshtanov

2011-05-07T23:59:59.000Z

390

DYNAMIC PHASORS IN MODELING, ANALYSIS AND CONTROL OF ENERGY  

E-Print Network [OSTI]

in: power electronics, electric drives and power systems. NEU Energy Processing Laboratory (1994) is a confluence of research and educational efforts: 1. Areas: power electronics, electric drives and power (ONR YIP) Systems Power Drives Electric Electronics Adaptive Converters Resonant Modeling Load

Stankoviæ, Aleksandar

391

Modelling the dynamical evolution of the Bootes dwarf spheroidal galaxy  

E-Print Network [OSTI]

We investigate a wide range of possible evolutionary histories for the recently discovered Bootes dwarf spheroidal galaxy, a Milky Way satellite. By means of N-body simulations we follow the evolution of possible progenitor galaxies of Bootes for a variety of orbits in the gravitational potential of the Milky Way. The progenitors considered cover the range from dark-matter-free star clusters to massive, dark-matter dominated outcomes of cosmological simulations. For each type of progenitor and orbit we compare the observable properties of the remnant after 10 Gyr with those of Bootes observed today. Our study suggests that the progenitor of Bootes must have been, and remains now, dark matter dominated. In general our models are unable to reproduce the observed high velocity dispersion in Bootes without dark matter. Our models do not support time-dependent tidal effects as a mechanism able to inflate significantly the internal velocity dispersion. As none of our initially spherical models is able to reproduce the elongation of Bootes, our results suggest that the progenitor of Bootes may have had some intrinsic flattening. Although the focus of the present paper is the Bootes dwarf spheroidal, these models may be of general relevance to understanding the structure, stability and dark matter content of all dwarf spheroidal galaxies.

M. Fellhauer; M. I. Wilkinson; N. W. Evans; V. Belokurov; M. J. Irwin; G. Gilmore; D. B. Zucker; J. T. Kleyna

2008-01-17T23:59:59.000Z

392

Static and Dynamic Debugging of Modelica Models Adrian Pop1  

E-Print Network [OSTI]

, Peter Fritzson1 , Francesco Casella2 1 Programming Environments Laboratory Department of Computer@elet.polimi.it Abstract The high abstraction level of equation-based object- oriented languages (EOO) such as Modelica has and algorithmic code debugging. Keywords: Modelica, Debugging, Modeling and Simulation, Transformations, Equations

Zhao, Yuxiao

393

Modeling the dynamics of tidally-interacting binary neutron stars up to merger  

E-Print Network [OSTI]

We propose an effective-one-body (EOB) model that describes the general relativistic dynamics of neutron star binaries from the early inspiral up to merger. Our EOB model incorporates an enhanced attractive tidal potential motivated by recent analytical advances in the post-Newtonian and gravitational self-force description of relativistic tidal interactions. No fitting parameters are introduced for the description of tidal interaction in the late, strong-field dynamics. We compare the model dynamics (described by the gauge invariant relation between binding energy and orbital angular momentum), and the gravitational wave phasing, with new high-resolution multi-orbit numerical relativity simulations of equal-mass configurations with different equations of state. We find agreement essentially within the uncertainty of the numerical data for all the configurations. Our model is the first semi-analytical model which captures the tidal amplification effects close to merger. It thereby provides the most accurate analytical representation of binary neutron star dynamics and waveforms currently available.

Sebastiano Bernuzzi; Alessandro Nagar; Tim Dietrich; Thibault Damour

2014-12-15T23:59:59.000Z

394

Multiple higher-order singularities and iso-dynamics in a simple glass-former model  

E-Print Network [OSTI]

We investigate the slow dynamics of a colloidal model with two repulsive length scales, whose interaction potential is the sum of a hard-core and a square shoulder. Despite the simplicity of the interactions, Mode-Coupling theory predicts a complex dynamic scenario: a fluid-glass line with two reentrances and a glass-glass line ending with multiple higher-order ($A_3$ or $A_4$) singularities. In this work we verify the existence of the two $A_4$ points by numerical simulations, observing subdiffusive behaviour of the mean-square displacement and logarithmic decay of the density correlators. Surprisingly, we also discover a novel dynamic behaviour generated by the competition between the two higher-order singularities. This results in the presence of special loci along which the dynamics is identical \\textit{at all} length and time scales.

Nicoletta Gnan; Gayatri Das; Matthias Sperl; Francesco Sciortino; Emanuela Zaccarelli

2014-07-15T23:59:59.000Z

395

Dynamics  

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

Hydration Hydration Water on Rutile Studied by Backscattering Neutron Spectroscopy and Molecular Dynamics Simulation E. Mamontov,* ,† D. J. Wesolowski, ‡ L. Vlcek, § P. T. Cummings, §,| J. Rosenqvist, ‡ W. Wang, ⊥ and D. R. Cole ‡ Spallation Neutron Source, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6473, Chemical Sciences DiVision, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6110, Department of Chemical Engineering, Vanderbilt UniVersity, NashVille, Tennessee 37235-1604, Center for Nanophase Materials Sciences, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6496, and EnVironmental Sciences DiVision, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831-6036 ReceiVed: December 20, 2007; ReVised Manuscript ReceiVed: June 4, 2008 The high energy resolution, coupled with the wide dynamic range, of the new backscattering

396

Dynamics of strong-coupling models for cuprate superconductors: Exact results on finite lattices  

SciTech Connect (OSTI)

We discuss recent applications of exact numerical continued fraction expansion (CFE) techniques to calculate dynamical correlation functions of various strong-coupling models related to the high-temperature cuprate superconductors. For the two-dimensional square-lattice spin-1/2 Heisenberg antiferromagnet, we present exact results for the zero-temperature dynamical structure factor on finite-sized lattices and compare them to approximate results from a Schwinger boson mean-field theory, recently proposed by Arovas and Auerbach. We find that the mean-field theory represents a very good approximation to the exact spin excitation spectra and to the static spin correlations. We then investigation the dynamical spin-spin structure factor and the single-particle spectral function for finite model clusters with dopant induced hole-type charge carriers, in the strong-coupling limit of both the single-band Hubbard model (t-J-model) and the three-band Hubbard model (Kondo-Heisenberg model). Our results are consistent with the physical picture recently proposed by Zhang and Rice which implies an approximate mapping of the low-energy states in the three-band model onto an effective single-band theory. 33 refs., 4 figs.

Schuettler, H.B.; Chen, C.-X. (Georgia Univ., Athens, GA (USA). Center for Simulational Physics); Fedro, A.J. (Argonne National Lab., IL (USA) Northern Illinois Univ., Dekalb, IL (USA). Dept. of Physics)

1989-01-01T23:59:59.000Z

397

Dynamic Light Scattering (DLS) What's it for: measuring the size of particles typically in the sub micron region,  

E-Print Network [OSTI]

Dynamic Light Scattering (DLS) · What's it for: measuring the size of particles typically weight of organic compounds. #12;·DLS Measurement: the speed at which the particles are diffusing due to Brownian motion is measured by recording the rate at which the intensity of the scattered light fluctuates

Subramanian, Venkat

398

ON THE FORMATION LOCATION OF URANUS AND NEPTUNE AS CONSTRAINED BY DYNAMICAL AND CHEMICAL MODELS OF COMETS  

SciTech Connect (OSTI)

The D/H enrichment observed in Saturn's satellite Enceladus is remarkably similar to the values observed in the nearly-isotropic comets. Given the predicted strong variation of D/H with heliocentric distance in the solar nebula, this observation links the primordial source region of the nearly-isotropic comets with the formation location of Enceladus. That is, comets from the nearly-isotropic class were most likely fed into their current reservoir, the Oort cloud, from a source region near the formation location of Enceladus. Dynamical simulations of the formation of the Oort cloud indicate that Uranus and Neptune are, primarily, responsible for the delivery of material into the Oort cloud. In addition, Enceladus formed from material that condensed from the solar nebula near the location at which Saturn captured its gas envelope, most likely at or near Saturn's current location in the solar system. The coupling of these lines of evidence appears to require that Uranus and Neptune were, during the epoch of the formation of the Oort cloud, much closer to the current location of Saturn than they are currently. Such a configuration is consistent with the Nice model of the evolution of the outer solar system. Further measurements of the D/H enrichment in comets, particularly in ecliptic comets, will provide an excellent discriminator among various models of the formation of the outer solar system.

Kavelaars, J. J. [Herzberg Institute of Astrophysics, National Research Council of Canada, 5071 West Saanich Road, Victoria, BC V9E 2E7 (Canada); Mousis, Olivier; Petit, Jean-Marc [Institut UTINAM, CNRS-UMR 6213, Observatoire de Besancon, BP 1615, 25010 Besancon Cedex (France); Weaver, Harold A., E-mail: JJ.Kavelaars@nrc.gc.ca [Space Department, Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723-6099 (United States)

2011-06-20T23:59:59.000Z

399

CB17: Inferring the dynamical history of a prestellar core with chemo-dynamical models  

E-Print Network [OSTI]

We present a detailed theoretical study of the isolated Bok globule CB17 (L1389) based on spectral maps of CS, HCO$^+$, C$^{18}$O, C$^{34}$S, and H$^{13}$CO$^+$ lines. A phenomenological model of prestellar core evolution, a time-dependent chemical model, and a radiative transfer simulation for molecular lines are combined to reconstruct the chemical and kinematical structure of this core. We developed a general criterion that allows to quantify the difference between observed and simulated spectral maps. By minimizing this difference, we find that very high and very low values of the effective sticking probability $S$ are not appropriate for the studied prestellar core. The most probable $S$ value for CB17 is 0.3--0.5. The spatial distribution of the intensities and self-absorption features of optically thick lines is indicative of UV irradiation of the core. By fitting simultaneously optically thin and optically thick transitions, we isolate the model that reproduces all the available spectral maps to a reasonable accuracy. The line asymmetry pattern in CB17 is reproduced by a combination of infall, rotation, and turbulent motions with velocities $\\sim0.05$ km s$^{-1}$, $\\sim0.1$ km s$^{-1}$, and $\\sim0.1$ km s$^{-1}$, respectively. These parameters corresponds to energy ratios $E_{\\rm rot}/E_{\\rm grav}\\approx0.03$, $E_{\\rm therm}/E_{\\rm grav}\\approx0.8$, and $E_{\\rm turb}/E_{\\rm grav}\\approx0.05$ (the rotation parameters are determined for $i=90^\\circ$). The chemical age of the core is about 2 Myrs. In particular, this is indicated by the central depletion of CO, CS, and HCO$^+$. Based on the angular momentum value, we argue that the core is going to fragment, i.e., to form a binary (multiple) star. (abridged)

Ya. Pavlyuchenkov; D. Wiebe; R. Launhardt; Th. Henning

2006-03-22T23:59:59.000Z

400

Physical Constraints on, and a Model for, the Active Regions in Seyfert Galaxies  

E-Print Network [OSTI]

We discuss several physical constraints on the nature of the Active Regions (AR) in Seyfert 1 Galaxies, and show that a plausible model consistent with these constraints is one in which the ARs are magnetically confined and ``fed''. The unique X-ray index of these sources points to a large compactness parameter ($l\\gg 1$). This, together with the conditions required to account for the observed optical depth being close to unity, suggests that the magnetic energy density in the AR should be comparable to the equipartition value in the accretion disk, and that it should be released in a flare-like event above the surface of the cold accretion disk. We consider the various issues pertaining to magnetic flares and attempt to construct a coherent picture, including a reason for the optical depth in the AR being $\\sim 1$, and an understanding of the characteristics of the X-ray reflection component and the power density spectra associated with this high-energy emission.

Sergei Nayakshin; Fulvio Melia

1997-05-30T23:59:59.000Z

Note: This page contains sample records for the topic "regional dynamics model" 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

Environment and the Lifetime of Tropical Deep Convection in a Cloud-Permitting Regional Model Simulation  

SciTech Connect (OSTI)

By applying a cloud tracking algorithm to tropical convective systems simulated by a regional high resolution model, the study documents environmental conditions before and after convective systems are initiated over ocean and land by following them during their lifetime. The comparative roles of various environmental fields in affecting the lifetime of convection are also quantified. The statistics of lifetime, maximum area, propagation speed and direction of the simulated deep convection agrees well with geostationary satellite observations. Over ocean, convective systems enhance surface fluxes through the associated wind gusts as well as cooling and drying of the boundary layer. A significant relationship is found between the mean surface fluxes during their lifetime and the longevity of the systems which in turn is related to the initial intensity of the moist updraft and to a lesser extent upper level shear. Over land, on the other hand, convective activity suppresses surface fluxes through cloud cover and the lifetime of convection is related to the upper level shear during their lifetime and strength of the heat fluxes several hours before the initiation of convection. For systems of equal lifetime, those over land are significantly more intense than those over ocean especially during early stages of their lifetime.

Hagos, Samson M.; Feng, Zhe; McFarlane, Sally A.; Leung, Lai-Yung R.

2013-08-01T23:59:59.000Z

402

IMA Journal of Applied Mathematics (2002) 67, 419439 Modelling thermal front dynamics in microwave heating  

E-Print Network [OSTI]

an electric field is applied to materials with high resistivity, the dipole moments of the molecules alignIMA Journal of Applied Mathematics (2002) 67, 419­439 Modelling thermal front dynamics in microwave July 2000; revised on 6 December 2001] The formation and propagation of thermal fronts in a cylindrical

Xin, Jack

403

Proper Orthogonal Decomposition-Based Modeling, Analysis, and Simulation of Dynamic Wind Load  

E-Print Network [OSTI]

Proper Orthogonal Decomposition-Based Modeling, Analysis, and Simulation of Dynamic Wind Load.1061/ ASCE 0733-9399 2005 131:4 325 CE Database subject headings: Simulation; Wind loads; Buildings; Random on the decomposition of the covariance and XPSD matrices is presented. A physically meaningful linkage between the wind

Chen, Xinzhong

404

Time Series Prediction by Chaotic Modeling of Nonlinear Dynamical Systems Arslan Basharat+  

E-Print Network [OSTI]

Inc. Clifton Park, NY, USA arslan.basharat@kitware.com Mubarak Shah+ + University of Central Florida Orlando, FL, USA shah@cs.ucf.edu Abstract We use concepts from chaos theory in order to model nonlinear dynamical systems that exhibit deterministic be- havior. Observed time series from such a system can be em

Central Florida, University of

405

Efficient Dynamic Modeling, Numerical Optimal Control and Experimental Results for Various Gaits  

E-Print Network [OSTI]

. A fully three- dimensional dynamical model of Sony's four-legged robot is used to state an optimal control robots is still a challenge. For a given gait pattern, landing time and point of each leg are prescribed, i.e. they depend on parameters. The trajectory of each joint between lift-off and landing

Stryk, Oskar von

406

On the self-similarity assumption in dynamic models for large eddy simulations  

E-Print Network [OSTI]

that the present formulation of the DP is usually incompatible with its under- lying self-similarity assumption SSAOn the self-similarity assumption in dynamic models for large eddy simulations Daniele Carati eddy simulations and their underlying self-similarity assumption is discussed. The interpretation

Van Den Eijnden, Eric

407

Radiated seismic energy based on dynamic rupture models of faulting and Ralph J. Archuleta1  

E-Print Network [OSTI]

Radiated seismic energy based on dynamic rupture models of faulting Shuo Ma1 and Ralph J. Archuleta energy from three hypothetical crustal events, 30° dipping reverse fault, 60° dipping normal fault, and 0.34 MPa for the reverse, normal, and strike-slip faults, respectively. The energy distribution

Archuleta, Ralph

408

Modeling Malware Propagation in Networks of Smart Cell Phones with Spatial Dynamics  

E-Print Network [OSTI]

Modeling Malware Propagation in Networks of Smart Cell Phones with Spatial Dynamics Krishna and worm attacks tar- geted at cell phones have have bought to the forefront the seriousness of the security threat to this increasingly popular means of communication. The ability of smart cell phones

Sikdar, Biplab

409

Condensation of helium in aerogels and athermal dynamics of the Random Field Ising Model  

E-Print Network [OSTI]

Condensation of helium in aerogels and athermal dynamics of the Random Field Ising Model Geoffroy J isotherms of 4He in a silica aerogel be- come discontinuous below a critical temperature. We show by the aerogel structure, but to the disorder-driven critical point predicted for the athermal out

Boyer, Edmond

410

Modelling of pH dynamics in brain cells after stroke  

Science Journals Connector (OSTI)

...pH increases their production [21-23]. Ca2...responsible for the production and consumption of hydrogen ions and hence the...clinical practice. 2. Methods The pH dynamics model...metabolism including H+ production and consumption...

2011-01-01T23:59:59.000Z

411

EMULATING A GRAVITY MODEL TO INFER THE SPATIOTEMPORAL DYNAMICS OF AN INFECTIOUS DISEASE  

E-Print Network [OSTI]

EMULATING A GRAVITY MODEL TO INFER THE SPATIOTEMPORAL DYNAMICS OF AN INFECTIOUS DISEASE Roman grid. · Use pre-calculated matrices {Mtk}. GP-EMULATOR - BASED APPROACH · Based on constructing a new (proportions of zeros) on a pre-selected grid of parameters. · Second stage: We make inference based

Bjørnstad, Ottar Nordal

412

Effects of Dynamic Forcing on Hillslope Water Balance Models , L.E. Band  

E-Print Network [OSTI]

simulations of the hillslope. In this work we focus specifically on closure relations for hillslope water]. Briefly stated, our objective in this work is to study the effect of system transience on hillslope waterEffects of Dynamic Forcing on Hillslope Water Balance Models C. E. Kees , L.E. Band , and M

413

Nonlinear dynamical systems with data and model uncertainties subjected to seismic loads  

E-Print Network [OSTI]

Nonlinear dynamical systems with data and model uncertainties subjected to seismic loads Christophe loads with data uncertainties for the nonlinearities. An application to a multisupported reactor coolant and Acoustics Dpt., 92141, Clamart cedex, France ABSTRACT This paper deals with data uncertainties

Paris-Sud XI, Université de

414

Modeling of impact dynamics of tennis ball with a flat surface  

E-Print Network [OSTI]

A two-mass model with a spring and a damper in the vertical direction, accounting for vertical translational motion and a torsional spring and a damper connecting the rotational motion of two masses is used to simulate the dynamics of a tennis ball...

Jafri, Syed M.

2005-08-29T23:59:59.000Z

415

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.

416

DYNAMIC MODEL OF AN INDUSTRIAL HEAT PUMP USING WATER AS REFRIGERANT  

E-Print Network [OSTI]

1 DYNAMIC MODEL OF AN INDUSTRIAL HEAT PUMP USING WATER AS REFRIGERANT CHAMOUN MARWAN to improve industrial energy efficiency, the development of a high temperature heat pump using water vapor as refrigerant is investigated. Technical problems restraining the feasibility of this industrial heat pump

Paris-Sud XI, Université de

417

Development of a Data Driven Dynamic Model for a Plasma Etching Reactor Michael Nikolaoua)  

E-Print Network [OSTI]

uniformity) to variations in input parameters (such as radio-frequency (rf) power, flow rate, dc bias, and energy balance equations inside a high-frequency, high-intensity electric field. Realistic simulation91 Development of a Data Driven Dynamic Model for a Plasma Etching Reactor Michael Nikolaoua

Nikolaou, Michael

418

Turbulent models of ice giant internal dynamics: Dynamos, heat transfer, and zonal flows  

E-Print Network [OSTI]

Turbulent models of ice giant internal dynamics: Dynamos, heat transfer, and zonal flows K Magnetic fields a b s t r a c t The ice giant planets, Uranus and Neptune, have magnetic fields to yield small-scale and disorganized turbulence. In agreement with ice giant observations, both

419

Global dynamics of a vector disease model with saturation incidence and time delay  

Science Journals Connector (OSTI)

......Journal of Applied Mathematics (2011) 76, 919-937 doi:10.1093/imamat/hxr013 Advance Access publication on March 17, 2011 Global dynamics of a vector disease model with saturation incidence and time delay RUI XU Institute of Applied Mathematics......

Rui Xu; Zhien Ma

2011-12-01T23:59:59.000Z

420

Modeling Sediment and Wood Storage and Dynamics in Small Mountainous Watersheds  

E-Print Network [OSTI]

85 Modeling Sediment and Wood Storage and Dynamics in Small Mountainous Watersheds Stephen T controls on supply and transport of sediment and wood in a small (approximately two square kilometers) basin in the Oregon Coast Range, typical of streams at the interface between episodic sediment and wood

Note: This page contains sample records for the topic "regional dynamics model" 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

Simplified dynamic models for control of riser slugging in offshore oil production  

E-Print Network [OSTI]

ForReview Only Simplified dynamic models for control of riser slugging in offshore oil production, Department of Chemical Engineering Keywords: oil production, two-phase flow, severe slugging, riser slugging for control of riser slugging in offshore oil production Esmaeil Jahanshahi, Sigurd Skogestad Department

Skogestad, Sigurd

422

Experimental Validation of a Computational Fluid Dynamics Model for IAQ applications in Ice Rink Arenas  

E-Print Network [OSTI]

1 Experimental Validation of a Computational Fluid Dynamics Model for IAQ applications in Ice Rink, USA, Fax: 617-432-4122, Abstract Many ice rink arenas have ice resurfacing equipment that uses fossil temperature distributions in ice rinks. The numerical results agree reasonably with the corresponding

Chen, Qingyan "Yan"

423

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

424

A simplified model of thin layer static/flowing dynamics for granular materials with yield  

E-Print Network [OSTI]

/deposition processes when a layer of particles is flowing over a static layer or near the destabilization and arrestA simplified model of thin layer static/flowing dynamics for granular materials with yield, 75005 Paris, France, 4 ANGE team, INRIA, CETMEF, Lab. J.-L. Lions, Paris, France Abstract We introduce

Paris-Sud XI, Université de

425

Modeling aspects of the ecological and evolutionary dynamics of the endangered Houston toad  

E-Print Network [OSTI]

-recapture techniques to estimate survivorship, and simulation modeling to explore the impacts of the difference in age at first reproduction and to project the future dynamics of the population at the GLR. From 2001 – 2005, 225 individual Houston toads (199 M : 26 F...

Swannack, Todd Michael

2009-05-15T23:59:59.000Z

426

Ecological Modelling 180 (2004) 135151 Simulating forest fuel and fire risk dynamics across  

E-Print Network [OSTI]

fuel module tracks fine fuel, coarse fuel and live fuel for each cell on a landscape. Fine fuel age (the oldest age cohorts) in combination with disturbance history. Live fuels, also called canopyEcological Modelling 180 (2004) 135­151 Simulating forest fuel and fire risk dynamics across

He, Hong S.

427

Simulation of ultrafast heating induced structural dynamics using a one-dimensional spring model  

Science Journals Connector (OSTI)

We developed a one-dimensional spring model to study the dynamics of lattice motion upon ultrafast laser heating. Using this model, we simulated atomic positions as a function of time in a free-standing thin monoatomic metal film as well as in a thin film on a substrate. In particular, we studied how the electronic thermal stress influences lattice expansion after the ultrafast laser heating. The simulation results agree very well with experimental data obtained with femtosecond electron diffraction.

Junjie Li; Rick Clinite; Xuan Wang; Jianming Cao

2009-07-22T23:59:59.000Z

428

Stochastic Dynamic Demand Inventory Models with Explicit Transportation Costs and Decisions  

E-Print Network [OSTI]

is the policy where several small loads will be dispatched as a single, combined load. From an inventory-modeling perspec- tive, the integrated inventory-transportation problems add dispatch quantities as decision variables to the stochastic dynamic inventory...): The vendor makes the inventory replen- ishment decisions on how much to order from the outside supplier. 2. Pure Outbound Transportation Models (PO): The collection depot makes the delivery schedules of order dispatches to the buyer(s). 3. Integrated...

Zhang, Liqing

2011-07-01T23:59:59.000Z

429

Computational fluid dynamics combustion modelling--A comparison of secondary air system designs  

SciTech Connect (OSTI)

A newly developed computer simulation of the combustion process in a kraft recovery furnace uses computational fluid dynamics to model the processes of mass, momentum, and energy transport. This paper describes two models and a presentation of the flow fields obtained. The results predict a dramatic improvement in combustion behavior using a refined secondary air system with reduction in particulate carryover, enhanced operating temperatures, more uniform gas flow, and less carbon monoxide at the furnace exit.

Jones, A.K. (ABB Combustion Engineering Systems, Ottawa, Ontario (Canada)); Chapman, P.J. (ABB Combustion Engineering Systems, Windsor, CT (United States))

1993-07-01T23:59:59.000Z

430

Simulation of polar stratospheric clouds in the specified dynamics version of the whole atmosphere community climate model  

E-Print Network [OSTI]

We evaluate the simulation of polar stratospheric clouds (PSCs) in the Specified Dynamics version of the Whole Atmosphere Community Climate Model for the Antarctic winter 2005. In this model, PSCs are assumed to form ...

Wegner, T.

431

Florian SEITZ: Atmospheric and oceanic impacts to Earth rotations numerical studies with a dynamic Earth system model  

E-Print Network [OSTI]

with a dynamic Earth system model (completed in October 2004) Variations of Earth rotation are caused Earth system model DyMEG has been developed. It is based on the balance of angular momentum

Schuh, Harald

432

The Impact of Land Surface Processes on Simulations of the U.S. Hydrological Cycle: A Case Study of the 1993 Flood Using the SSiB Land Surface Model in the NCEP Eta Regional Model  

Science Journals Connector (OSTI)

This paper describes a methodology for coupling the Simplified Simple Biosphere Model (SSiB) to the regional Eta Model of the National Centers for Environmental Prediction (NCEP), and presents the application of the coupled system in regional ...

Y. Xue; F. J. Zeng; K. E. Mitchell; Z. Janjic; E. Rogers

2001-12-01T23:59:59.000Z

433

Quantum Quenches and Off-Equilibrium Dynamical Transition in the Infinite-Dimensional Bose-Hubbard Model  

SciTech Connect (OSTI)

We study the off-equilibrium dynamics of the infinite-dimensional Bose-Hubbard model after a quantum quench. The dynamics can be analyzed exactly by mapping it to an effective Newtonian evolution. For integer filling, we find a dynamical transition separating regimes of small and large quantum quenches starting from the superfluid state. This transition is very similar to the one found for the fermionic Hubbard model by mean field approximations.

Sciolla, Bruno; Biroli, Giulio [Institut de Physique Theorique, CEA/DSM/IPhT-CNRS/URA 2306 CEA-Saclay, F-91191 Gif-sur-Yvette (France)

2010-11-26T23:59:59.000Z

434

Dynamic electro-thermal modeling of all-vanadium redox flow battery with forced cooling strategies  

Science Journals Connector (OSTI)

Abstract The present study focuses on the dynamic electro-thermal modeling for the all-vanadium redox flow battery (VRB) with forced cooling strategies. The Foster network is adopted to dynamically model the heat dissipation of VRB with heat exchangers. The parameters of Foster network are extracted by fitting the step response of it to the results of linearized CFD model. Then a complete electro-thermal model is proposed by coupling the heat generation model, Foster network and electrical model. Results show that the established model has nearly the same accuracy with the nonlinear CFD model in electrolyte temperature prediction but drastically improves the computational efficiency. The modeled terminal voltage is also benchmarked with the experimental data under different current densities. The electrolyte temperature is found to be significantly influenced by the flow rate of coolant. As compared, although the electrolyte flow rate has unremarkable impact on electrolyte temperature, its effect on system pressure drop and battery efficiency is significant. Increasing the electrolyte flow rate improves the coulombic efficiency, voltage efficiency and energy efficiency simultaneously but at the expense of higher pump power demanded. An optimal flow rate exists for each operating condition to maximize the system efficiency.

Zhongbao Wei; Jiyun Zhao; Binyu Xiong

2014-01-01T23:59:59.000Z

435

Fault detection and isolation of a dual spool gas turbine engine using dynamic neural networks and multiple model approach  

Science Journals Connector (OSTI)

In this paper, a fault detection and isolation (FDI) scheme for an aircraft jet engine is developed. The proposed FDI system is based on the multiple model approach and utilizes dynamic neural networks (DNNs) to accomplish this goal. Towards this end, ... Keywords: Bank of detection and isolation filters, Dual spool gas turbine engine, Dynamic neural networks, Fault diagnosis, Multiple model scheme

Z. N. Sadough Vanini; K. Khorasani; N. Meskin

2014-02-01T23:59:59.000Z

436

Dynamic Thermal Model of Polymer Electrolyte Membrane (PEM) Fuel Cell Budi Hadisujoto, Rehan Refai, Dongmei Chen, Tess J. Moon  

E-Print Network [OSTI]

Dynamic Thermal Model of Polymer Electrolyte Membrane (PEM) Fuel Cell Budi Hadisujoto, Rehan Refai to improve the performance of a PEM fuel cell Simulation Results Advanced Power Systems and Controls (GDL) to reduce water saturation · Model water transport in PEM fuel cell Contribution: · Dynamic

Ben-Yakar, Adela

437

Technical Review of the CENWP Computational Fluid Dynamics Model of the John Day Dam Forebay  

SciTech Connect (OSTI)

The US Army Corps of Engineers Portland District (CENWP) has developed a computational fluid dynamics (CFD) model of the John Day forebay on the Columbia River to aid in the development and design of alternatives to improve juvenile salmon passage at the John Day Project. At the request of CENWP, Pacific Northwest National Laboratory (PNNL) Hydrology Group has conducted a technical review of CENWP's CFD model run in CFD solver software, STAR-CD. PNNL has extensive experience developing and applying 3D CFD models run in STAR-CD for Columbia River hydroelectric projects. The John Day forebay model developed by CENWP is adequately configured and validated. The model is ready for use simulating forebay hydraulics for structural and operational alternatives. The approach and method are sound, however CENWP has identified some improvements that need to be made for future models and for modifications to this existing model.

Rakowski, Cynthia L.; Serkowski, John A.; Richmond, Marshall C.

2010-12-01T23:59:59.000Z

438

Using Advanced Technology-Rich Models for Regional And Global Economic Analysis of GHG Mitigation  

Science Journals Connector (OSTI)

This article presents the case for a detailed regional analysis of the economic impacts of GHG control, via a set of inter-connected...

Richard Loulou; Amit Kanudia

2002-01-01T23:59:59.000Z

439

E-Print Network 3.0 - active region model Sample Search Results  

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

Collection: Physics 72 The main rationale In the 21st Summary: development in the ASEAN region. Chapter 3: The Space Activities of ASEAN Countries investigates the...

440

European Wind Energy Conference & Exhibition EWEC 2003, Madrid, Spain. Forecasting of Regional Wind Generation by a Dynamic  

E-Print Network [OSTI]

European Wind Energy Conference & Exhibition EWEC 2003, Madrid, Spain. Forecasting of Regional Wind forecasting. I. INTRODUCTION HE actual large-scale integration of wind energy in several European countries enhance the position of wind energy compared to other dispatchable forms of generation. Predicting

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "regional dynamics model" 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

DYNAMIC MODELING STRATEGY FOR FLOW REGIME TRANSITION IN GAS-LIQUID TWO-PHASE FLOWS  

SciTech Connect (OSTI)

In modeling gas-liquid two-phase flows, the concept of flow regime has been used to characterize the global interfacial structure of the flows. Nearly all constitutive relations that provide closures to the interfacial transfers in two-phase flow models, such as the two-fluid model, are often flow regime dependent. Currently, the determination of the flow regimes is primarily based on flow regime maps or transition criteria, which are developed for steady-state, fully-developed flows and widely applied in nuclear reactor system safety analysis codes, such as RELAP5. As two-phase flows are observed to be dynamic in nature (fully-developed two-phase flows generally do not exist in real applications), it is of importance to model the flow regime transition dynamically for more accurate predictions of two-phase flows. The present work aims to develop a dynamic modeling strategy for determining flow regimes in gas-liquid two-phase flows through the introduction of interfacial area transport equations (IATEs) within the framework of a two-fluid model. The IATE is a transport equation that models the interfacial area concentration by considering the creation and destruction of the interfacial area, such as the fluid particle (bubble or liquid droplet) disintegration, boiling and evaporation; and fluid particle coalescence and condensation, respectively. For the flow regimes beyond bubbly flows, a two-group IATE has been proposed, in which bubbles are divided into two groups based on their size and shape (which are correlated), namely small bubbles and large bubbles. A preliminary approach to dynamically identifying the flow regimes is provided, in which discriminators are based on the predicted information, such as the void fraction and interfacial area concentration of small bubble and large bubble groups. This method is expected to be applied to computer codes to improve their predictive capabilities of gas-liquid two-phase flows, in particular for the applications in which flow regime transition occurs.

X. Wang; X. Sun; H. Zhao

2011-09-01T23:59:59.000Z

442

ONE-DIMENSIONAL MODELING FOR TEMPERATURE-DEPENDENT UPFLOW IN THE DIMMING REGION OBSERVED BY HINODE/EUV IMAGING SPECTROMETER  

SciTech Connect (OSTI)

We previously found a temperature-dependent upflow in the dimming region following a coronal mass ejection observed by the Hinode EUV Imaging Spectrometer (EIS). In this paper, we reanalyzed the observations along with previous work on this event and provided boundary conditions for modeling. We found that the intensity in the dimming region dramatically drops within 30 minutes from the flare onset, and the dimming region reaches the equilibrium stage after {approx}1 hr. The temperature-dependent upflows were observed during the equilibrium stage by EIS. The cross-sectional area of the flux tube in the dimming region does not appear to expand significantly. From the observational constraints, we reconstructed the temperature-dependent upflow by using a new method that considers the mass and momentum conservation law and demonstrated the height variation of plasma conditions in the dimming region. We found that a super-radial expansion of the cross-sectional area is required to satisfy the mass conservation and momentum equations. There is a steep temperature and velocity gradient of around 7 Mm from the solar surface. This result may suggest that the strong heating occurred above 7 Mm from the solar surface in the dimming region. We also showed that the ionization equilibrium assumption in the dimming region is violated, especially in the higher temperature range.

Imada, S.; Shimizu, T. [Institute of Space and Astronautical Science, Japan Aerospace Exploration Agency, 3-1-1 Yoshinodai, Chuo-ku, Sagamihara-shi, Kanagawa 252-5210 (Japan); Hara, H.; Watanabe, T. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka-shi, Tokyo 181-8588 (Japan); Murakami, I. [National Institute for Fusion Science, 322-6 Oroshi-cho, Toki, Gifu 509-5292 (Japan); Harra, L. K. [UCL-Mullard Space Science Laboratory, Holmbury St Mary, Dorking, Surrey, RH5 6NT (United Kingdom); Zweibel, E. G. [Department of Astronomy, University of Wisconsin-Madison, 475 N Charter Street, Madison, WI 53706 (United States)

2011-12-10T23:59:59.000Z

443

Superscaling and Charge-Changing Neutrino Scattering from Nuclei in the $\\boldsymbol ?$-Region beyond the Relativistic Fermi Gas Model  

E-Print Network [OSTI]

The superscaling analysis using the scaling function obtained within the coherent density fluctuation model is extended to calculate charge-changing neutrino and antineutrino scattering on $^{12}$C at energies from 1 to 2 GeV not only in the quasielastic but also in the delta excitation region. The results are compared with those obtained using the scaling functions from the relativistic Fermi gas model and from the superscaling analysis of inclusive scattering of electrons from nuclei.

M. V. Ivanov; M. B. Barbaro; J. A. Caballero; A. N. Antonov; E. Moya de Guerra; M. K. Gaidarov

2008-02-29T23:59:59.000Z

444

Short-time dynamics of Fe{sub 2}/V{sub 13} magnetic superlattice models  

SciTech Connect (OSTI)

Critical relaxation from a low-temperature fully ordered state of Fe{sub 2}/V{sub 13} iron-vanadium magnetic superlattice models has been studied using the method of short-time dynamics. Systems with three variants of the ratio R of inter-to intralayer exchange coupling have been considered. Particles with N = 262144 spins have been simulated with periodic boundary conditions. Calculations have been performed using the standard Metropolis algorithm of the Monte Carlo method. The static critical exponents of magnetization and correlation radius, as well as the dynamic critical exponent, have been calculated for three R values. It is established that a small decrease in the exchange ratio (from R = 1.0 to 0.8) does not significantly influence the character of the short-time dynamics in the models studied. A further significant decrease in this ratio (to R = 0.01), for which a transition from three-dimensional to quasi-two-dimensional magnetism is possible, leads to significant changes in the dynamic behavior of iron-vanadium magnetic superlattice models.

Murtazaev, A. K.; Mutailamov, V. A., E-mail: vadim.mut@mail.ru [Russian Academy of Sciences, Amirkhanov Institute of Physics, Daghestan Scientific Center (Russian Federation)

2013-04-15T23:59:59.000Z

445

Using Multi-scale Dynamic Rupture Models to Improve Ground Motion Estimates  

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

Earthquake simulations help scientists understand the hazards posed by Earthquake simulations help scientists understand the hazards posed by future earthquakes. Earthquake computational models are validated by simulating well-recorded historical earthquakes and comparing simulation results to observational data. The purple border shows the extent of the 3-D structural model in the 3-D inversion. Events in red, with stations in blue. En-Jui Lee, University of Wyoming Using Multi-scale Dynamic Rupture Models to Improve Ground Motion Estimates PI Name: Thomas Jordan PI Email: tjordan@usc.edu Institution: USC Allocation Program: ESP Allocation Hours at ALCF: 150 Million Year: 2010 to 2013 Research Domain: Earth Science Researchers will use Southern California Earthquake Center (SCEC) dynamic rupture simulation software to investigate high-frequency seismic energy

446

Dynamic modeling and optimal control strategy of waste heat recovery Organic Rankine Cycles  

Science Journals Connector (OSTI)

Organic Rankine Cycles (ORCs) are particularly suitable for recovering energy from low-grade heat sources. This paper describes the behavior of a small-scale ORC used to recover energy from a variable flow rate and temperature waste heat source. A traditional static model is unable to predict transient behavior in a cycle with a varying thermal source, whereas this capability is essential for simulating an appropriate cycle control strategy during part-load operation and start and stop procedures. A dynamic model of the ORC is therefore proposed focusing specifically on the time-varying performance of the heat exchangers, the dynamics of the other components being of minor importance. Three different control strategies are proposed and compared. The simulation results show that a model predictive control strategy based on the steady-state optimization of the cycle under various conditions is the one showing the best results.

Sylvain Quoilin; Richard Aumann; Andreas Grill; Andreas Schuster; Vincent Lemort; Hartmut Spliethoff

2011-01-01T23:59:59.000Z

447

GIS-based energy-economic model of low temperature geothermal resources: A case study in the Italian Marche region  

Science Journals Connector (OSTI)

This paper presents a computational procedure designed to derive a regional model of the low temperature geothermal potential and its economic exploitability. The model was applied to the Italian Marche region and developed with the support of a Geographic Information System (GIS), which highlights the spatial dependencies in the distribution of geothermic resources. The Low Temperature Geothermal Energy has already gained attention as a renewable energy resource for domestic heating and represents a growing opportunity for investment. Although it is common practice to conduct an accurate evaluation of the geothermal potential and its exploitability on a site during the construction of a single installation, there is not an established practice or guidelines for estimating this resource over large territories. This information could support an institution’s ability to conduct regional energy planning and guide private entrepreneurship to meet new economic opportunities. To address these issues, the main contribution of this work is a model that reduces the distance between the physical knowledge of the territory/environment and economic analysis. The model is based on a useful assessment of low temperature geothermal potential obtained from physical parameters on a regional scale, from which a set of economic indicators are calculated to evaluate the actual economic accessibility to the geothermal energy resource.

Alberto Gemelli; Adriano Mancini; Sauro Longhi

2011-01-01T23:59:59.000Z

448

Sub-national TIMES model for analyzing regional future use of Biomass and Biofuels in France and  

E-Print Network [OSTI]

1 Sub-national TIMES model for analyzing regional future use of Biomass and Biofuels in France Introduction Renewable energy sources such as biomass and biofuels are increasingly being seen as important of biofuels on the final consumption of energy in transport should be 10%. The long-term target is to reduce

Boyer, Edmond

449

A Comparative Study of Precipitation and Evaporation between CMIP3 and CMIP5 Climate Model Ensembles in Semiarid Regions  

Science Journals Connector (OSTI)

The twentieth-century climatology and twenty-first-century trend in precipitation P, evaporation E, and P ? E for selected semiarid U.S. Southwest and Mediterranean regions are compared between ensembles from phases 3 and 5 of the Coupled Model ...

Noel C. Baker; Huei-Ping Huang

2014-05-01T23:59:59.000Z

450

Aeroelastic Modeling of Offshore Turbines and Support Structures in Hurricane-Prone Regions (Poster)  

SciTech Connect (OSTI)

US offshore wind turbines (OWTs) will likely have to contend with hurricanes and the associated loading conditions. Current industry standards do not account for these design load cases (DLCs), thus a new approach is required to guarantee that the OWTs achieve an appropriate level of reliability. In this study, a sequentially coupled aero-hydro-servo-elastic modeling technique was used to address two design approaches: 1.) The ABS (American Bureau of Shipping) approach; and 2.) The Hazard Curve or API (American Petroleum Institute) approach. The former employs IEC partial load factors (PSFs) and 100-yr return-period (RP) metocean events. The latter allows setting PSFs and RP to a prescribed level of system reliability. The 500-yr RP robustness check (appearing in [2] and [3] upcoming editions) is a good indicator of the target reliability for L2 structures. CAE tools such as NREL's FAST and Bentley's' SACS (offshore analysis and design software) can be efficiently coupled to simulate system loads under hurricane DLCs. For this task, we augmented the latest FAST version (v. 8) to include tower aerodynamic drag that cannot be ignored in hurricane DLCs. In this project, a 6 MW turbine was simulated on a typical 4-legged jacket for a mid-Atlantic site. FAST-calculated tower base loads were fed to SACS at the interface level (transition piece); SACS added hydrodynamic and wind loads on the exposed substructure, and calculated mudline overturning moments, and member and joint utilization. Results show that CAE tools can be effectively used to compare design approaches for the design of OWTs in hurricane regions and to achieve a well-balanced design, where reliability levels and costs are optimized.

Damiani, R.

2014-03-01T23:59:59.000Z

451

Dynamic customisation, validation and integration of product data models using semantic web tools  

Science Journals Connector (OSTI)

Standard product data models enable information exchange across different organisations, actors, processes and stages in the product lifecycle. These standard models need to support diverse domain-specific requirements from the multitude of disciplines involved during a product's lifecycle. Due to this diversity, challenges are to: 1) develop multidisciplinary models; 2) extend them to support new requirements over time; 3) implement the resulting gigantic information models. ISO 10303, the reference standard for PLM-related data models provides mechanisms to enable specialisation of generic product data to address some of these challenges. In this paper, we introduce the need for dynamic product data models, detail the ISO method and identify its limitations. We present enhancements to that methodology using ontologies and the SPARQL Inference Notation (SPIN) for validating product data. To conclude, we show how these ontologies can be leveraged to ease and strengthen PLM data integration through the use of Linked Data.

Sylvere Krima; Allison Barnard Feeney; Sebti Foufou

2014-01-01T23:59:59.000Z

452

A finite-patch model of a flexible plate via Kane's dynamics  

Science Journals Connector (OSTI)

Military hardware must undergo extensive shock-response analysis to predict survivability to mechanical shock. Although finite element modelling is commonly used to model such hardware, alternative methods which offer the possibility of shorter modelling, modification, or simulation times continue to be desirable. This research effort applies Kane's dynamics to the problem of plate modelling, toward shock-response analysis of homogeneous plates having various geometries and boundary conditions. Analytical equations of motion are found for a continuous flexible plate that is discretised in checkerboard fashion as a patchwork of rigid rectangular patches connected by flexible springs and damped modally. A MATLAB implementation is used to validate the model against pertinent analytical and numerical benchmark analyses, for a variety of boundary conditions. The model is then reduced by applying non-holonomic constraints directly using Kane's method, and revalidated via MATLAB for a rectangular plate in simple support.

R. David Hampton

2012-01-01T23:59:59.000Z

453

Renormalization of lattice-regularized quantum gravity models II. The case of causal dynamical triangulations  

E-Print Network [OSTI]

The causal dynamical triangulations approach aims to construct a quantum theory of gravity as the continuum limit of a lattice-regularized model of dynamical geometry. A renormalization group scheme--in concert with finite size scaling analysis--is essential to this aim. Formulating and implementing such a scheme in the present context raises novel and notable conceptual and technical problems. I explored these problems, and, building on standard techniques, suggested potential solutions in the first paper of this two-part series. As an application of these solutions, I now propose a renormalization group scheme for causal dynamical triangulations. This scheme differs significantly from that studied recently by Ambjorn, Gorlich, Jurkiewicz, Kreienbuehl, and Loll.

Joshua H. Cooperman

2014-06-17T23:59:59.000Z

454

Energy systems planning and GHG-emission control under uncertainty in the province of Liaoning, China – A dynamic inexact energy systems optimization model  

Science Journals Connector (OSTI)

Abstract In this study, a dynamic interval-parameter optimization model (DIP-REM) has been developed for supporting long-term energy systems planning in association with GHG mitigation in the region of Liaoning province. The model can describe Liaoning province energy planning systems as networks of a series of energy flows, transferring extracted/imported energy resources to end users through a variety of conversion and transmission technologies over a number of periods and address the problem of GHG-emission reduction within a general energy planning systems framework under uncertainty. Two scenarios (including a reference case) are considered corresponding to different GHG-emission mitigation levels for in-depth analysis of interactions existing among energy, socio-economy and environment in the Liaoning province. Useful solutions for Liaoning province energy planning systems have been generated, reflecting trade-offs among energy-related, environmental and economic considerations. The results can not only provide optimal energy resource/service allocation and capacity-expansion plans, but also help decision-makers identify desired policies for GHG mitigation with a cost-effective manner in the region of Liaoning province. Thus, it can be used by decision makers as an effective technique in examining and visualizing impacts of energy and environmental policies, regional development strategies and emission reduction measures within an integrated and dynamic framework.

J. Liu; Q.G. Lin; G.H. Huang; Q. Wu; H.P. Li

2013-01-01T23:59:59.000Z

455

Regional groundwater modeling of the saturated zone in the vicinity of Yucca Mountain, Nevada; Iterative Performance Assessment, Phase 2  

SciTech Connect (OSTI)

Results of groundwater modeling of the saturated zone in the vicinity of Yucca Mountain are presented. Both a regional (200 {times} 200 km) and subregional (50 {times} 50 km) model were used in the analyses. Simulations were conducted to determine the impact of various disruptive that might take place over the life span of a proposed Yucca Mountain geologic conditions repository on the groundwater flow field, as well as changes in the water-table elevations. These conditions included increases in precipitation and groundwater recharge within the regional model, changes in permeability of existing hydrogeologic barriers, a:nd the vertical intrusion of volcanic dikes at various orientations through the saturated zone. Based on the regional analysis, the rise in the water-table under Yucca Mountain due to various postulated conditions ranged from only a few meters to 275 meters. Results of the subregional model analysis, which was used to simulate intrusive dikes approximately 4 kilometers in length in the vicinity of Yucca Mountain, showed water-table rises ranging from a few meters to as much as 103 meters. Dikes oriented approximately north-south beneath Yucca Mountain produced the highest water-table rises. The conclusions drawn from this analysis are likely to change as more site-specific data become available and as the assumptions in the model are improved.

Ahola, M.; Sagar, B. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses

1992-10-01T23:59:59.000Z

456

Introduction to the application of the dynamical systems theory in the study of the dynamics of cosmological models of dark energy  

E-Print Network [OSTI]

The theory of the dynamical systems is a very complex subject which has brought several surprises in the recent past in connection with the theory of chaos and fractals. The application of the tools of the dynamical systems in cosmological settings is less known in spite of the amount of published scientific papers on this subject. In this paper a -- mostly pedagogical -- introduction to the application in cosmology of the basic tools of the dynamical systems theory is presented. It is shown that, in spite of their amazing simplicity, these allow to extract essential information on the asymptotic dynamics of a wide variety of cosmological models. The power of these tools is illustrated within the context of the so called $\\Lambda$CDM and scalar field models of dark energy. This paper is suitable for teachers, undergraduate and postgraduate students from physics and mathematics disciplines.

García-Salcedo, Ricardo; Horta-Rangel, Francisco A; Quiros, Israel; Sanchez-Guzmán, Daniel

2015-01-01T23:59:59.000Z

457

Modelling China’s potential maize production at regional scale under climate change  

Science Journals Connector (OSTI)

With the continuing warming due to greenhouse gases concentration, it is important to examine the potential impacts on regional crop production spatially and temporally. We assessed China’s potential maize pro...

Wei Xiong; Robin Matthews; Ian Holman; Erda Lin; Yinglong Xu

2007-12-01T23:59:59.000Z

458

New Theoretical Model of the Complex Edge Region of Fusion Plasmas...  

Office of Science (SC) Website

a high pedestal is required for copious fusion energy production in ITER or a fusion power plant, and (2) the large free energy in the pedestal region can drive instabilities...

459

Modeling regional transportation demand in China and the impacts of a national carbon constraint  

E-Print Network [OSTI]

Climate and energy policy in China will have important and uneven impacts on the country’s regionally heterogeneous transport system. In order to simulate these impacts, transport sector detail is added to a multi-sector, ...

Kishimoto, Paul

2015-01-30T23:59:59.000Z

460

Modeling regional seismic waves from underground nuclear explosion. Report for 17 March 1987-30 March 88  

SciTech Connect (OSTI)

Two main topics are presented: the effects of ocean continent transition zones on L - g waves; and modeling regional Love waves with 2-D velocity structures. Hybrid regional and teleseismic SH mode sum seismograms are produced after propagation through a regional transition zone or other heterogeneity that exists as part of a longer, mostly plane-layered, path. In particular the effects of ocean continent transition regions of geometry for propagation along a partially oceanic path is at most a factor of four. Extending the oceanic path length changes this factor to at most 6. This is inadequate to explain the observed attenuation of Lg. Thus, additional effects, must be considered to provide a complete explanation of the attenuation of Lg. Long period seismograms recorded at Pasadena of earthquakes occurring along a profile to Imperial Valley are studied in terms of source phenomena versus path effects. Some of the events have known source parameters, determined by teleseismic or near-field studies, and are used as master events in a forward modeling exercise to derive the Green's functions that describe the propagation effects along the profile. Both timing and waveforms of records are matched by synthetics calculated from 2-dimensional velocity models. The best 2-dimensional section begins at Imperial Valley with a thin crust containing the basin structure and thickens towards Pasadena.

Clayton, R.W.; Harkrider, D.G.; Helmberger, D.V.

1988-05-09T23:59:59.000Z

Note: This page contains sample records for the topic "regional dynamics model" 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.


461

Classical dynamics and localization of resonances in the high energy region of the hydrogen atom in crossed fields  

E-Print Network [OSTI]

When superimposing the potentials of external fields on the Coulomb potential of the hydrogen atom a saddle point appears, which is called the Stark saddle point. For energies slightly above the saddle point energy one can find classical orbits, which are located in the vicinity of this point. We follow those so-called quasi-Penning orbits to high energies and field strengths observing structural changes and uncovering their bifurcation behavior. By plotting the stability behavior of those orbits against energy and field strength the appearance of a stability apex is reported. A cusp bifurcation, located in the vicinity of the apex, will be investigated in detail. In this cusp bifurcation another orbit of similar shape is found, which becomes completely stable in the observed region of positive energy, i.e., in a region of parameter space, where the Kepler-like orbits located around the nucleus are already unstable. By quantum-mechanically exact calculations we prove the existence of signatures in quantum spectra belonging to those orbits. Husimi distributions are used to compare quantum-Poincar\\'e sections with the extension of the classical torus structure around the orbits. Since periodic orbit theory predicts that each classical periodic orbit contributes an oscillating term to photoabsorption spectra, we finally give an estimation for future experiments, which could verify the existence of the stable orbits.

Frank Schweiner; Jörg Main; Holger Cartarius; Günter Wunner

2014-12-10T23:59:59.000Z

462

Control method and system for hydraulic machines employing a dynamic joint motion model  

DOE Patents [OSTI]

A control method and system for controlling a hydraulically actuated mechanical arm to perform a task, the mechanical arm optionally being a hydraulically actuated excavator arm. The method can include determining a dynamic model of the motion of the hydraulic arm for each hydraulic arm link by relating the input signal vector for each respective link to the output signal vector for the same link. Also the method can include determining an error signal for each link as the weighted sum of the differences between a measured position and a reference position and between the time derivatives of the measured position and the time derivatives of the reference position for each respective link. The weights used in the determination of the error signal can be determined from the constant coefficients of the dynamic model. The error signal can be applied in a closed negative feedback control loop to diminish or eliminate the error signal for each respective link.

Danko, George (Reno, NV)

2011-11-22T23:59:59.000Z

463

A Nonlocal Peridynamic Plasticity Model for the Dynamic Flow and Fracture of Concrete.  

SciTech Connect (OSTI)

A nonlocal, ordinary peridynamic constitutive model is formulated to numerically simulate the pressure-dependent flow and fracture of heterogeneous, quasi-brittle ma- terials, such as concrete. Classical mechanics and traditional computational modeling methods do not accurately model the distributed fracture observed within this family of materials. The peridynamic horizon, or range of influence, provides a characteristic length to the continuum and limits localization of fracture. Scaling laws are derived to relate the parameters of peridynamic constitutive model to the parameters of the classical Drucker-Prager plasticity model. Thermodynamic analysis of associated and non-associated plastic flow is performed. An implicit integration algorithm is formu- lated to calculate the accumulated plastic bond extension and force state. The gov- erning equations are linearized and the simulation of the quasi-static compression of a cylinder is compared to the classical theory. A dissipation-based peridynamic bond failure criteria is implemented to model fracture and the splitting of a concrete cylinder is numerically simulated. Finally, calculation of the impact and spallation of a con- crete structure is performed to assess the suitability of the material and failure models for simulating concrete during dynamic loadings. The peridynamic model is found to accurately simulate the inelastic deformation and fracture behavior of concrete during compression, splitting, and dynamically induced spall. The work expands the types of materials that can be modeled using peridynamics. A multi-scale methodology for simulating concrete to be used in conjunction with the plasticity model is presented. The work was funded by LDRD 158806.

Vogler, Tracy; Lammi, Christopher James

2014-10-01T23:59:59.000Z

464

Development of a regional groundwater flow model for the area of the Idaho National Engineering Laboratory, Eastern Snake River Plain Aquifer  

SciTech Connect (OSTI)

This report documents a study conducted to develop a regional groundwater flow model for the Eastern Snake River Plain Aquifer in the area of the Idaho National Engineering Laboratory. The model was developed to support Waste Area Group 10, Operable Unit 10-04 groundwater flow and transport studies. The products of this study are this report and a set of computational tools designed to numerically model the regional groundwater flow in the Eastern Snake River Plain aquifer. The objective of developing the current model was to create a tool for defining the regional groundwater flow at the INEL. The model was developed to (a) support future transport modeling for WAG 10-04 by providing the regional groundwater flow information needed for the WAG 10-04 risk assessment, (b) define the regional groundwater flow setting for modeling groundwater contaminant transport at the scale of the individual WAGs, (c) provide a tool for improving the understanding of the groundwater flow system below the INEL, and (d) consolidate the existing regional groundwater modeling information into one usable model. The current model is appropriate for defining the regional flow setting for flow submodels as well as hypothesis testing to better understand the regional groundwater flow in the area of the INEL. The scale of the submodels must be chosen based on accuracy required for the study.

McCarthy, J.M.; Arnett, R.C.; Neupauer, R.M. [and others

1995-03-01T23:59:59.000Z

465

Generalized spherically symmetric gravitational model: Hamiltonian dynamics in extended phase space and BRST charge  

E-Print Network [OSTI]

We construct Hamiltonian dynamics of the generalized spherically symmetric gravitational model in extended phase space. We start from the Faddeev - Popov effective action with gauge-fixing and ghost terms, making use of gauge conditions in differential form. It enables us to introduce missing velocities into the Lagrangian and then construct a Hamiltonian function according a usual rule which is applied for systems without constraints. The main feature of Hamiltonian dynamics in extended phase space is that it can be proved to be completely equivalent to Lagrangian dynamics derived from the effective action. We find a BRST invariant form of the effective action by adding terms not affecting Lagrangian equations. After all, we construct the BRST charge according to the Noether theorem. Our algorithm differs from that by Batalin, Fradkin and Vilkovisky, but the resulting BRST charge generates correct transformations for all gravitational degrees of freedom including gauge ones. Generalized spherically symmetric model imitates the full gravitational theory much better then models with finite number of degrees of freedom, so that one can expect appropriate results in the case of the full theory.

T. P. Shestakova

2014-06-12T23:59:59.000Z

466

Detuning Induced Effects: Symmetry-Breaking Bifurcations in Dynamic Model of One-Mode Laser  

E-Print Network [OSTI]

The concept of broken symmetry is used to study bifurcations of equilibria and dynamical instabilities in dynamic model of one-mode laser (nonresonant complex Lorenz model) on the basis of modified Hopf theory. It is shown that an invariant set of stationary points bifurcates into an invariant torus (doubly-periodic branching solution). Influence of the symmetry breaking on stability of branching solutions is investigated as a function of detuning. The invariant torus is found to be stable under the detuning exceeds its critical value, so that dynamically broken symmetry results in the apprearance of low-frequency Goldstone-type mode. If the detuning then goes downward and pumping is kept above the threshold, numerical analysis reveals that after a cascade of period-doublings the strange Lorenz attractor is formed at small values of detuning. It is found that there are three types of the system behavior as pumping increases depending on the detuning. Quantum counterpart of the complex Lorenz model is discussed.

Alexei D. Kiselev

1998-01-15T23:59:59.000Z

467

A spectral transform dynamical core option within the Community Atmosphere Model (CAM4)  

SciTech Connect (OSTI)

A spectral transform dynamical core with an 85 spectral truncation resolution (T85) within the Community Atmosphere Model (CAM), version 4, is evaluated within the recently released Community Earth System Model, version 1.0 (CESM) global climate model. The spectral dynamical core option provides a well-known base within the climate model community from which to assess climate behavior and statistics, and its relative computational efficiency for smaller computing platforms allows it to be extended to perform climate length simulations using high-resolution configurations in the near term. To establish the characteristics of the CAM4 T85, an ensemble of simulations covering the present day observational period using forced sea surface temperatures and prescribed sea-ice extent are evaluated. Overall, the T85 ensemble attributes and biases are similar to a companion ensemble of simulations using the one degree finite volume (FV1) dynamical core, relative to observed and model derived datasets. Notable improvements with T85 compared to FV1 include the representation of wintertime Arctic sea level pressure and summer precipitation over the Western Indian subcontinent. The mean and spatial patterns of the land surface temperature trends over the AMIP period are generally well simulated with the T85 ensemble relative to observations, however the model is not able to capture the extent nor magnitude of changes in temperature extremes over the boreal summer, where the changes are most dramatic. Biases in the wintertime Arctic surface temperature and annual mean surface stress fields persist with T85 as with the CAM3 version of T85.

Evans, Katherine J [ORNL; Mahajan, Salil [ORNL; Branstetter, Marcia L [ORNL; McClean, Julie L. [Scripps Institute of Oceanography; Caron, Julie M. [National Center for Atmospheric Research (NCAR); Maltrud, Matthew E. [Los Alamos National Laboratory (LANL); Hack, James J [ORNL; Bader, David C [ORNL; Neale, Rich [National Center for Atmospheric Research (NCAR)

2014-01-01T23:59:59.000Z

468

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

469

Modeling the dynamic response of pressures in a distributed helium refrigeration system  

SciTech Connect (OSTI)

A mathematical model is created of the dynamic response of pressures caused by flow inputs to an existing distributed helium refrigeration system. The dynamic system studied consists of the suction and discharge pressure headers and compressor portions of the refrigeration system used to cool the superconducting magnets of the Tevatron accelerator at the Fermi National Accelerator Laboratory. The modeling method involves identifying the system from data recorded during a series of controlled tests, with effort made to detect locational differences in pressure response around the four mile accelerator circumference. A review of the fluid mechanics associated with the system indicates linear time invariant models are suitable for the identification, particularly since the governing equations of one dimensional fluid flow are approximated by linear differential equations. An outline of the experimental design and the data acquisition system are given, followed by a detailed description of the modeling, which utilized the Matlab programming language and associated System Identification Toolbox. Two representations of the system are presented. One, a black box model, provides a multi-input, multi-output description assembled from the results of single input step function testing. This description indicates definite variation in pressure response with distance from the flow input location, and also suggests subtle differences in response with the input location itself. A second system representation is proposed which details the relation between continuous flow changes and pressure response, and provides explanation of a previously unappreciated pressure feedback internal to the system.

Brubaker, J.C.

1997-12-01T23:59:59.000Z

470

Region-based quantitative and hierarchical attribute reduction in the two-category decision theoretic rough set model  

Science Journals Connector (OSTI)

Abstract Quantitative attribute reduction exhibits applicability but complexity when compared to qualitative reduction. According to the two-category decision theoretic rough set model, this paper mainly investigates quantitative reducts and their hierarchies (with qualitative reducts) from a regional perspective. (1) An improved type of classification regions is proposed, and its preservation reduct (CRP-Reduct) is studied. (2) Reduction targets and preservation properties of set regions are analyzed, and the set-region preservation reduct (SRP-Reduct) is studied. (3) Separability of set regions and rule consistency is verified, and the quantitative and qualitative double-preservation reduct (DP-Reduct) is established. (4) Hierarchies of CRP-Reduct, SRP-Reduct, and DP-Reduct are explored with two qualitative reducts: the Pawlak-Reduct and knowledge-preservation reduct (KP-Reduct). (5) Finally, verification experiments are provided. CRP-Reduct, SRP-Reduct, and DP-Reduct expand layer by layer Pawlak-Reduct and exhibit quantitative applicability, and the experimental results indicate their effectiveness and hierarchies regarding Pawlak-Reduct and KP-Reduct.

Xianyong Zhang; Duoqian Miao

2014-01-01T23:59:59.000Z

471

A validated dynamic model of the first marine molten carbonate fuel cell  

Science Journals Connector (OSTI)

In this work we present a modular, dynamic and multi-dimensional model of a molten carbonate fuel cell (MCFC) onboard the offshore supply vessel “Viking Lady” serving as an auxiliary power unit. The model is able to capture detailed thermodynamic, heat transfer and electrochemical reaction phenomena within the fuel cell layers. The model has been calibrated and validated with measured performance data from a prototype installation onboard the vessel. The model is able to capture detailed thermodynamic, heat transfer and electrochemical reaction phenomena within the fuel cell layers. The model has been calibrated and validated with measured performance data from a prototype installation onboard the offshore supply vessel. The calibration process included parameter identification, sensitivity analysis to identify the critical model parameters, and iterative calibration of these to minimize the overall prediction error. The calibrated model has a low prediction error of 4% for the operating range of the cell, exhibiting at the same time a physically sound qualitative behavior in terms of thermodynamic heat transfer and electrochemical phenomena, both on steady-state and transient operation. The developed model is suitable for a wide range of studies covering the aspects of thermal efficiency, performance, operability, safety and endurance/degradation, which are necessary to introduce fuel cells in ships. The aim of this MCFC model is to aid to the introduction, design, concept approval and verification of environmentally friendly marine applications such as fuel cells, in a cost-effective, fast and safe manner.

E. Ovrum; G. Dimopoulos

2012-01-01T23:59:59.000Z

472

Reconstructing generalized ghost condensate model with dynamical dark energy parametrizations and observational datasets  

E-Print Network [OSTI]

Observations of high-redshift supernovae indicate that the universe is accelerating at the present stage, and we refer to the cause for this cosmic acceleration as ``dark energy''. In particular, the analysis of current data of type Ia supernovae (SNIa), cosmic large-scale structure (LSS), and the cosmic microwave background (CMB) anisotropy implies that, with some possibility, the equation-of-state parameter of dark energy may cross the cosmological-constant boundary ($w=-1$) during the recent evolution stage. The model of ``quintom'' has been proposed to describe this $w=-1$ crossing behavior for dark energy. As a single-real-scalar-field model of dark energy, the generalized ghost condensate model provides us with a successful mechanism for realizing the quintom-like behavior. In this paper, we reconstruct the generalized ghost condensate model in the light of three forms of parametrization for dynamical dark energy, with the best-fit results of up-to-date observational data.

Jingfei Zhang; Xin Zhang; Hongya Liu

2007-03-21T23:59:59.000Z

473

Computational fluid dynamics modeling of coal gasification in a pressurized spout-fluid bed  

SciTech Connect (OSTI)

Computational fluid dynamics (CFD) modeling, which has recently proven to be an effective means of analysis and optimization of energy-conversion processes, has been extended to coal gasification in this paper. A 3D mathematical model has been developed to simulate the coal gasification process in a pressurized spout-fluid bed. This CFD model is composed of gas-solid hydrodynamics, coal pyrolysis, char gasification, and gas phase reaction submodels. The rates of heterogeneous reactions are determined by combining Arrhenius rate and diffusion rate. The homogeneous reactions of gas phase can be treated as secondary reactions. A comparison of the calculated and experimental data shows that most gasification performance parameters can be predicted accurately. This good agreement indicates that CFD modeling can be used for complex fluidized beds coal gasification processes. 37 refs., 7 figs., 5 tabs.

Zhongyi Deng; Rui Xiao; Baosheng Jin; He Huang; Laihong Shen; Qilei Song; Qianjun Li [Southeast University, Nanjing (China). Key Laboratory of Clean Coal Power Generation and Combustion Technology of Ministry of Education

2008-05-15T23:59:59.000Z

474

Incorporating daily flood control objectives into a monthly stochastic dynamic programming model for a hydroelectric complex  

SciTech Connect (OSTI)

A monthly stochastic dynamic programing model was recently developed and implemented at British Columbia (B.C.) Hydro to provide decision support for short-term energy exports and, if necessary, for flood control on the Peace River in northern British Columbia. The model established the marginal cost of supplying energy from the B.C. Hydro system, as well as a monthly operating policy for the G.M. Shrum and Peace Canyon hydroelectric plants and the Williston Lake storage reservoir. A simulation model capable of following the operating policy then determines the probability of refilling Williston Lake and possible spill rates and volumes. Reservoir inflows are input to both models in daily and monthly formats. The results indicate that flood control can be accommodated without sacrificing significant export revenue.

Druce, D.J. (British Columbia Hydro and Power Authority, Vancouver, British Columbia (Canada))

1990-01-01T23:59:59.000Z

475

ON THE DYNAMICS OF THE SOLAR CORONA: FIRST RESULTS OBTAINED WITH A NEW 3D MHD MODEL  

E-Print Network [OSTI]

1 ON THE DYNAMICS OF THE SOLAR CORONA: FIRST RESULTS OBTAINED WITH A NEW 3D MHD MODEL J. Kleimann 1) is applied to the problem of the dynamics of the solar corona. First, we present the basic system of equations for a two- uid description of the solar wind plasma and point out possible numerical di

Grauer, Rainer

476

Proceedings of 2009 NSF Engineering Research and Innovation Conference, Honolulu, Hawaii Grant #0838874 Dynamic Modeling of a Regenerator for the  

E-Print Network [OSTI]

#0838874 Dynamic Modeling of a Regenerator for the Control-Based Design of Free-Piston Stirling Engines-piston Stirling engines with the goal of building a working prototype. The Stirling cycle is recast as a dynamic the potential of a new, compact free-piston Stirling engine configuration using elastomeric pistons. An engine

Barth, Eric J.

477

Protein folding dynamics in lattice model with physical movement Sema Kachalo, Hsiao-Mei Lu and Jie Liang  

E-Print Network [OSTI]

Protein folding dynamics in lattice model with physical movement S¨ema Kachalo, Hsiao-Mei Lu analysis of the kinetic energy landscape. I. INTRODUCTION The dynamics of protein folding has been studied exten- sively [1, 3­5]; A remarkable empirical observation is that protein folding rates are well

Dai, Yang

478

Modeling the sorption dynamics of NaH using a reactive force field J. G. O. Ojwang,1,a  

E-Print Network [OSTI]

Modeling the sorption dynamics of NaH using a reactive force field J. G. O. Ojwang,1,a Rutger van that the fall in potential energy is associated with either cluster fragmentation or de- sorption of molecular ReaxFFNaAlH4 to study the structural and dynamical details of hydrogen ab de sorption processes in Na

Goddard III, William A.

479

A RESTRICTED FOUR-BODY MODEL FOR THE DYNAMICS NEAR THE LAGRANGIAN POINTS OF THE SUN-JUPITER  

E-Print Network [OSTI]

A RESTRICTED FOUR-BODY MODEL FOR THE DYNAMICS NEAR THE LAGRANGIAN POINTS OF THE SUN-JUPITER SYSTEM focus on the dynamics of a small particle near the Lagrangian points of the Sun-Jupiter system. To try solution of the planar three-body problem for Sun, Jupiter and Saturn, close to the real motion

480

Transport pathways and signatures of mixing in the extratropical tropopause region derived from Lagrangian model simulations  

E-Print Network [OSTI]

,2 I. Pollack,2,3 A. Weinheimer,2 J. Wei,4,5 E. L. Atlas,6 and K. P. Bowman7 Received 6 August 2010 (STE) in the extratropical tropopause region plays an important role in trace gas composition, will be analyzed using tracers of air mass origin in Lagrangian simulations. [3] In situ measurements of trace

Pan, Laura

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