Effective viscosity of active suspensions: Three-dimensional numerical modeling
Levan Jibuti; Walter Zimmermann; Salima Rafaï; Philippe Peyla
2014-12-10T23:59:59.000Z
A three-dimensional model is proposed for Chlamydomonas Reinhardtii swimming with a breaststroke-like beating of its two flagella. The model reveals unusual angular orbits of the active swimmer under a linear shear flow. Namely, the swimmer sustains orientation transiently across the flow when flagella plane is perpendicular to the shear plane, and amplify the shear-induced rotation along the flow. Such behavior is a result of the interplay between shear-induced deformation and swimmer's periodic beating motion that exerts internal torques on the torque-free swimmer. This particular behavior has some significant consequences on the rheological properties of the suspension that tends to confirm previous experimental results [Phys. Rev. Lett. 104, 098102 (2010)]. We calculated the intrinsic viscosity of the suspension with such isolated modeled microswimmers (dilute case) in shear flow using numerical simulations based on Rotne-Prager approximation. The results show an increased intrinsic viscosity for active swimmer suspensions in comparison to non-active ones in accordance with previous experimental measurements. A major enhancement of the active swimmer viscosity occurs due to the effectively extended shape of the deformable swimming cells. We also recover the experimentally observed shear thinning behavior.
Numerical simulation of micro-fluidic passive and active mixers
Kumar, Saurabh
2002-01-01T23:59:59.000Z
Numerical simulations of mixing using passive and active techniques are performed. For passive mixing, numerical modeling of a micro-fluidic device, build by Holden and Cremer, was performed. The micro-fluidic device consists of a Y...
Numerical Modeling of HCCI Combustion
Broader source: Energy.gov (indexed) [DOE]
Numerical Modeling of HCCI Combustion Salvador M. Aceves, Daniel L. Flowers, J. Ray Smith, Joel Martinez-Frias, Francisco Espinosa-Loza, Tim Ross, Bruce Buchholz, Nick...
Studied models Numerical scheme
Helluy, Philippe
: Sound speed: c0 = 1500m/s Pressure: p0 = 105Pa Density: 0 = 1000kg/m3 Vapor: 1 = 1.4 (1 = 0) Water: 2. Helluy, S. MÂ¨uller HÂ´el`ene Mathis Micro-Macro Modelling and Simulation of Liquid-Vapour Flows #12 approximations HÂ´el`ene Mathis Micro-Macro Modelling and Simulation of Liquid-Vapour Flows #12;Studied models
Numerical Modeling At Dixie Valley Geothermal Area (McKenna ...
McKenna & Blackwell, 2003) Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Exploration Activity: Numerical Modeling At Dixie Valley Geothermal Area (McKenna &...
Guerin, Gilles
productive reservoirs of the EI330 oil field. #12;126 4.2 Introduction The Eugene Island 330 (EI330) oil sensitive to the movement of strong seismic events such as oil/water and gas/oil contacts on the scale for the dynamics of active oil fields. Here, Plio- Pleistocene sandstone reservoirs are supplied with mature
Numerical modeling of vertical cavity semiconductor lasers
Chow, W.W.; Hadley, G.R.
1996-08-01T23:59:59.000Z
A vertical cavity surface emitting laser (VCSEL) is a diode laser whose optical cavity is formed by growing or depositing DBR mirror stacks that sandwich an active gain region. The resulting short cavity supports lasing into a single longitudinal mode normal to the wafer, making these devices ideal for a multitude of applications, ranging from high-speed communication to high-power sources (from 2D arrays). This report describes the development of a numerical VCSEL model, whose goal is to both further their understanding of these complex devices and provide a tool for accurate design and data analysis.
Numerical wind speed simulation model
Ramsdell, J.V.; Athey, G.F.; Ballinger, M.Y.
1981-09-01T23:59:59.000Z
A relatively simple stochastic model for simulating wind speed time series that can be used as an alternative to time series from representative locations is described in this report. The model incorporates systematic seasonal variation of the mean wind, its standard deviation, and the correlation speeds. It also incorporates systematic diurnal variation of the mean speed and standard deviation. To demonstrate the model capabilities, simulations were made using model parameters derived from data collected at the Hanford Meteorology Station, and results of analysis of simulated and actual data were compared.
Numerical modelling and analysis of a room temperature magnetic
Numerical modelling and analysis of a room temperature magnetic refrigeration system Thomas Frank and analysis of a room temperature magnetic refrigeration system Department: Fuel Cells and Solid State-dimensional mathematical model of an Active Magnetic Regenerator (AMR) system which is used for magnetic refrigeration
High performance computing and numerical modelling
,
2014-01-01T23:59:59.000Z
Numerical methods play an ever more important role in astrophysics. This is especially true in theoretical works, but of course, even in purely observational projects, data analysis without massive use of computational methods has become unthinkable. The key utility of computer simulations comes from their ability to solve complex systems of equations that are either intractable with analytic techniques or only amenable to highly approximative treatments. Simulations are best viewed as a powerful complement to analytic reasoning, and as the method of choice to model systems that feature enormous physical complexity such as star formation in evolving galaxies, the topic of this 43rd Saas Fee Advanced Course. The organizers asked me to lecture about high performance computing and numerical modelling in this winter school, and to specifically cover the basics of numerically treating gravity and hydrodynamics in the context of galaxy evolution. This is still a vast field, and I necessarily had to select a subset ...
Lattice Boltzmann Model for Numerical Relativity
Ilseven, E
2015-01-01T23:59:59.000Z
In the Bona-Masso formulation, Einstein equations are written as a set of flux conservative first order hyperbolic equations that resemble fluid dynamics equations. Based on this formulation, we construct a lattice Boltzmann model for Numerical Relativity. Our model is validated with well-established tests, showing good agreement with analytical solutions. Furthermore, we show that by increasing the relaxation time, we gain stability at the cost of losing accuracy, and by decreasing the lattice spacings while keeping a constant numerical diffusivity, the accuracy and stability of our simulations improves. Finally, in order to show the potential of our approach a linear scaling law for parallelisation with respect to number of CPU cores is demonstrated. Our model represents the first step in using lattice kinetic theory to solve gravitational problems.
NUMERICAL MODELING OF CATHODE CONTACT MATERIAL DENSIFICATION
Koeppel, Brian J.; Liu, Wenning N.; Stephens, Elizabeth V.; Khaleel, Mohammad A.
2011-11-01T23:59:59.000Z
Numerical modeling was used to simulate the constrained sintering process of the cathode contact layer during assembly of solid oxide fuel cells (SOFCs). A finite element model based on the continuum theory for sintering of porous bodies was developed and used to investigate candidate low-temperature cathode contact materials. Constitutive parameters for various contact materials under investigation were estimated from dilatometry screening tests, and the influence of processing time, processing temperature, initial grain size, and applied compressive stress on the free sintering response was predicted for selected candidate materials. The densification behavior and generated stresses within a 5-cell planar SOFC stack during sintering, high temperature operation, and room temperature shutdown were predicted. Insufficient constrained densification was observed in the stack at the proposed heat treatment, but beneficial effects of reduced grain size, compressive stack preload, and reduced thermal expansion coefficient on the contact layer densification and stresses were observed.
A numerical model of aerosol scavenging
Bradley, M.M.; Molenkamp, C.R.
1991-10-01T23:59:59.000Z
Using a three-dimensional numerical cloud/smoke-plume model, we have simulated the burning of a large, mid-latitude city following a nuclear exchange. The model includes 18 dynamic and microphysical equations that predict the fire-driven airflow, cloud processes, and smoke-cloud interactions. In the simulation, the intense heating from the burning city produces a firestorm with updraft velocities exceeding 60 m/s. Within 15 minutes of ignition, the smoke plume penetrates the tropopause. The updraft triggers a cumulonimbus cloud that produces significant quantities of ice, snow, and hail. These solid hydrometeors, as well as cloud droplets and rain, interact with the smoke particles from the fire. At the end of the one-hour simulation, over 20% of the smoke is in slowly falling snowflakes. If the snow reaches the ground before the flakes completely sublimate (or melt and then evaporate), then only approximately 50% of the smoke will survive the scavenging processes and remain in the atmosphere to affect the global climate.
Numerical Modeling of the Nucleation Conditions of Petal-Centerline...
Coso Geothermal Field Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Proceedings: Numerical Modeling of the Nucleation Conditions of...
Buoyant melting instabilities beneath extending lithosphere: 1. Numerical models
Tackley, Paul J.
Buoyant melting instabilities beneath extending lithosphere: 1. Numerical models John W. Hernlund,1,2 Paul J. Tackley,1,3 and David J. Stevenson4 Received 18 November 2006; revised 18 October 2007 diffusely extending lithosphere is studied using numerical convection models covering a wide range
Evolution of the Bohemian Massif: Insights from numerical modeling
Cerveny, Vlastislav
Evolution of the Bohemian Massif: Insights from numerical modeling Petra Maierová Supervisor: Doc of Geophysics Faculty of Mathematics and Physics Charles University in Prague #12;February 4, 2013Evolution Conclusions Outline #12;February 4, 2013Evolution of the Bohemian Massif: Insights from numerical modeling 3
NUMERICAL MODELING FOR MULTIPHASE INCOMPRESSIBLE FLOW WITH PHASE CHANGE
Abdou, Mohamed
NUMERICAL MODELING FOR MULTIPHASE INCOMPRESSIBLE FLOW WITH PHASE CHANGE Xiao-Yong Luo, Ming-Jiu Ni for multiphase flows. A con- tinuum surface force (CSF) tension model is used in the present cases. Phase change
Material model library for explicit numerical codes
Hofmann, R.; Dial, B.W.
1982-08-01T23:59:59.000Z
A material model logic structure has been developed which is useful for most explicit finite-difference and explicit finite-element Lagrange computer codes. This structure has been implemented and tested in the STEALTH codes to provide an example for researchers who wish to implement it in generically similar codes. In parallel with these models, material parameter libraries have been created for the implemented models for materials which are often needed in DoD applications.
A numerical model of perturbation gas chromatography
DeBarro, Marc Joseph
1985-01-01T23:59:59.000Z
the polymer and the solvent. Flory (1965) extended his original model to account for the volume changes in the polymer phase. A further model was suggested by Sanchez and Lacombe (1978) based on s. lattice fluid theory. For the system examined in this work...
Numerical studies of a simple Coulomb blockade model
Shao, Jianfeng
1991-01-01T23:59:59.000Z
NUMERICAL STUDIES OF A SIMPLE COULOMB BLOCKADE MODEL A Thesis by JIANFENG SHAO Submitted to the Office of Graduate Studies of Texas ASM University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE August 1991... Major Subject: Physics NUMERICAL STUDIES OF A SIMPLE COULOMB BLOCKADE MODEL A Thesis by JIANFENG SHAO Approved as to style and content by: Roland E, Allen (Chair of Committee) /, 1 r oseph H. R s ( Member) Chin B. Su (Member) Richard L...
Category:Numerical Modeling | Open Energy Information
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand JumpConceptual Model, click here. Category:Conceptual ModelLists forMercury VaporTemplatespage? For
SEQUESTRATION OF METALS IN ACTIVE CAP MATERIALS: A LABORATORY AND NUMERICAL EVALUATION
Dixon, K.; Knox, A.
2012-02-13T23:59:59.000Z
Active capping involves the use of capping materials that react with sediment contaminants to reduce their toxicity or bioavailability. Although several amendments have been proposed for use in active capping systems, little is known about their long-term ability to sequester metals. Recent research has shown that the active amendment apatite has potential application for metals contaminated sediments. The focus of this study was to evaluate the effectiveness of apatite in the sequestration of metal contaminants through the use of short-term laboratory column studies in conjunction with predictive, numerical modeling. A breakthrough column study was conducted using North Carolina apatite as the active amendment. Under saturated conditions, a spike solution containing elemental As, Cd, Co, Se, Pb, Zn, and a non-reactive tracer was injected into the column. A sand column was tested under similar conditions as a control. Effluent water samples were periodically collected from each column for chemical analysis. Relative to the non-reactive tracer, the breakthrough of each metal was substantially delayed by the apatite. Furthermore, breakthrough of each metal was substantially delayed by the apatite compared to the sand column. Finally, a simple 1-D, numerical model was created to qualitatively predict the long-term performance of apatite based on the findings from the column study. The results of the modeling showed that apatite could delay the breakthrough of some metals for hundreds of years under typical groundwater flow velocities.
Numerical Models of Blackbody-Dominated GRBs
Cuesta-Martínez, Carlos F; Mimica, Petar; Thöne, Christina C; de Ugarte-Postigo, Antonio
2015-01-01T23:59:59.000Z
Blackbody-dominated (BBD) gamma-ray bursts (GRBs) are events characterized by the absence of a typical afterglow, long durations and the presence of a significant thermal component following the prompt gamma-ray emission. GRB 101225A (the `Christmas burst') is a prototype of this class. A plausible progenitor system for it, and for the BBD-GRBs, is the merger of a neutron star (NS) and a helium core of an evolved, massive star. Using relativistic hydrodynamic simulations we model the propagation of an ultrarelativistic jet through the enviroment created by such a merger and we compute the whole radiative signature, both thermal and non-thermal, of the jet dynamical evolution. We find that the thermal emission originates from the interaction between the jet and the hydrogen envelope ejected during the NS/He merger.
Diffusion and Dispersion Characterization of a Numerical Tsunami Model
Tolkova, Elena
and numerical model. This plan is currently under devel- opment at the NCTR and a proof of concept has been-computed database of unit source solutions to determine the offshore tsunami waves. It then uses the MOST model (in nested grid mode) to propagate the offshore waves onshore for select regions. The critical factor
Numerical Modeling of Brain Dynamics in Traumatic Situations -Impulsive Translations
Burtscher, Martin
.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
155: Numerical Models of Groundwater Flow and Transport
Sorek, Shaul
155: Numerical Models of Groundwater Flow and Transport EKKEHARD HOLZBECHER1 AND SHAUL SOREK2 1. #12;2402 GROUNDWATER Calibration as a task cannot be separated from the other tasks. Inverse modeling of the Negev, J. Blaustein Institutes for Desert Research, Sede Boker, Israel The article gives an introduction
Aguilar, Guillermo
Numerical modeling of spray cooling-assisted dermatologic laser surgery for treatment of port wine to the epidermis during dermatologic laser surgery (DLS) for removal of port wine stain (PWS) birthmarks heat (J/kg/K) c speed of light in i (m/s) D optical diffusion coefficient (m) Ea activation energy
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative1 First Use of Energy for All Purposes (Fuel and Nonfuel), 2002; Level:Energy: Grid Integration Redefining What's Possible for Renewable Energy:Nanowire3627 Federal RegisterImplementation andNumerical simulations
Friction versus dilation revisited: Insights from theoretical and numerical models
Einat, Aharonov
Friction versus dilation revisited: Insights from theoretical and numerical models N. Makedonska,1 controlled by the frictional strength of the fault gouge, a granular layer that accumulates between the fault friction coefficient) of such granular layers is the systems resistance to dilation, a byprocess
Numerical Modeling of the 2011 Tohoku Earthquake Tsunami
Frandsen, Jannette B.
Evolution of Ocean WAVEs) to reconstruct the tsunami across the Pacific and its transformation aroundNumerical Modeling of the 2011 Tohoku Earthquake Tsunami Yoshiki Yamazaki Post-doctoral Research 2011 Tohoku earthquake (Mw 9.0) generated a massive tsunami devastated the entire Pacific coast
Department of Numerical Analysis Modeling the Austenite Ferrite
Vuik, Kees
Department of Numerical Analysis Modeling the Austenite Ferrite Transformation by Cellular Ferrite Transformation by Cellular Automaton Improving Interface Stability Master of Science Thesis. Computational Materials Science 48.3 (2010): 692-699] for the austenite to ferrite transformation in low
Direct Numerical Simulations and Modeling of Jets in Crossflow
Mahesh, Krishnan
Direct Numerical Simulations and Modeling of Jets in Crossflow A THESIS SUBMITTED TO THE FACULTY. i #12;To my parents and my grandparents, and to Ramnath ii #12;Abstract Jets in crossflow are used to study the different aspects of round jets in a crossflow. The first problem studies
Constitutive modeling of active polymers
Therkelsen, Scott V. (Scott Vincent), 1980-
2005-01-01T23:59:59.000Z
This thesis develops a three-dimensional constitutive model of active polymeric materials, including changes in material volume and properties due to actuation. Active polymers reversibly change shape, volume and/or material ...
On numerical considerations for modeling reactive astrophysical shocks
Papatheodore, Thomas L.; Messer, O. E. Bronson, E-mail: tpapathe@utk.edu, E-mail: bronson@ornl.gov [Department of Physics and Astronomy, University of Tennessee, Knoxville, TN 37996 (United States)
2014-02-10T23:59:59.000Z
Simulating detonations in astrophysical environments is often complicated by numerical approximations to shock structure. A common prescription to ensure correct detonation speeds and associated quantities is to prohibit burning inside the numerically broadened shock. We have performed a series of simulations to verify the efficacy of this approximation and to understand how resolution and dimensionality might affect its use. Our results show that in one dimension, prohibiting burning in the shock is important wherever the carbon burning length is not resolved, in keeping with the results of Fryxell et al. In two dimensions, we find that the prohibition of shock burning effectively inhibits the development of cellular structure for all but the most highly resolved cases. We discuss the possible impacts this outcome may have on sub-grid models and detonation propagation in models of Type Ia supernovae, including potential impacts on observables.
Refined numerical models for multidimensional Type Ia supernova simulations
Reinecke, M; Niemeyer, J C
2002-01-01T23:59:59.000Z
Following up on earlier work on this topic (Reinecke et al. 1999, A&A 347, pp. 724 and 739), we present an improved set of numerical models for simulations of white dwarfs exploding as Type Ia supernovae (SNe Ia). Two-dimensional simulations were used to test the reliability and numerical robustness of these algorithms; the results indicate that integral quantities like the total energy release are insensitive to changes of the grid resolution (above a certain threshold), which was not the case for our former code. The models were further enhanced to allow fully three-dimensional simulations of SNe Ia. A direct comparison of a 2D and a 3D calculation with identical initial conditions shows that the explosion is considerably more energetic in three dimensions; this is most likely caused by the assumption of axisymmetry in 2D, which inhibits the growth of flame instabilities in the azimuthal direction and thereby decreases the flame surface.
Refined numerical models for multidimensional Type Ia supernova simulations
M. Reinecke; W. Hillebrandt; J. C. Niemeyer
2001-11-26T23:59:59.000Z
Following up on earlier work on this topic (Reinecke et al. 1999, A&A 347, pp. 724 and 739), we present an improved set of numerical models for simulations of white dwarfs exploding as Type Ia supernovae (SNe Ia). Two-dimensional simulations were used to test the reliability and numerical robustness of these algorithms; the results indicate that integral quantities like the total energy release are insensitive to changes of the grid resolution (above a certain threshold), which was not the case for our former code. The models were further enhanced to allow fully three-dimensional simulations of SNe Ia. A direct comparison of a 2D and a 3D calculation with identical initial conditions shows that the explosion is considerably more energetic in three dimensions; this is most likely caused by the assumption of axisymmetry in 2D, which inhibits the growth of flame instabilities in the azimuthal direction and thereby decreases the flame surface.
ASSIMILATION OF DOPPLER RADAR DATA INTO NUMERICAL WEATHER MODELS
Chiswell, S.; Buckley, R.
2009-01-15T23:59:59.000Z
During the year 2008, the United States National Weather Service (NWS) completed an eight fold increase in sampling capability for weather radars to 250 m resolution. This increase is expected to improve warning lead times by detecting small scale features sooner with increased reliability; however, current NWS operational model domains utilize grid spacing an order of magnitude larger than the radar data resolution, and therefore the added resolution of radar data is not fully exploited. The assimilation of radar reflectivity and velocity data into high resolution numerical weather model forecasts where grid spacing is comparable to the radar data resolution was investigated under a Laboratory Directed Research and Development (LDRD) 'quick hit' grant to determine the impact of improved data resolution on model predictions with specific initial proof of concept application to daily Savannah River Site operations and emergency response. Development of software to process NWS radar reflectivity and radial velocity data was undertaken for assimilation of observations into numerical models. Data values within the radar data volume undergo automated quality control (QC) analysis routines developed in support of this project to eliminate empty/missing data points, decrease anomalous propagation values, and determine error thresholds by utilizing the calculated variances among data values. The Weather Research and Forecasting model (WRF) three dimensional variational data assimilation package (WRF-3DVAR) was used to incorporate the QC'ed radar data into input and boundary conditions. The lack of observational data in the vicinity of SRS available to NWS operational models signifies an important data void where radar observations can provide significant input. These observations greatly enhance the knowledge of storm structures and the environmental conditions which influence their development. As the increase in computational power and availability has made higher resolution real-time model simulations possible, the need to obtain observations to both initialize numerical models and verify their output has become increasingly important. The assimilation of high resolution radar observations therefore provides a vital component in the development and utility of numerical model forecasts for both weather forecasting and contaminant transport, including future opportunities to improve wet deposition computations explicitly.
Mathematical and Numerical Analyses of Peridynamics for Multiscale Materials Modeling
Du, Qiang
2014-11-12T23:59:59.000Z
The rational design of materials, the development of accurate and efficient material simulation algorithms, and the determination of the response of materials to environments and loads occurring in practice all require an understanding of mechanics at disparate spatial and temporal scales. The project addresses mathematical and numerical analyses for material problems for which relevant scales range from those usually treated by molecular dynamics all the way up to those most often treated by classical elasticity. The prevalent approach towards developing a multiscale material model couples two or more well known models, e.g., molecular dynamics and classical elasticity, each of which is useful at a different scale, creating a multiscale multi-model. However, the challenges behind such a coupling are formidable and largely arise because the atomistic and continuum models employ nonlocal and local models of force, respectively. The project focuses on a multiscale analysis of the peridynamics materials model. Peridynamics can be used as a transition between molecular dynamics and classical elasticity so that the difficulties encountered when directly coupling those two models are mitigated. In addition, in some situations, peridynamics can be used all by itself as a material model that accurately and efficiently captures the behavior of materials over a wide range of spatial and temporal scales. Peridynamics is well suited to these purposes because it employs a nonlocal model of force, analogous to that of molecular dynamics; furthermore, at sufficiently large length scales and assuming smooth deformation, peridynamics can be approximated by classical elasticity. The project will extend the emerging mathematical and numerical analysis of peridynamics. One goal is to develop a peridynamics-enabled multiscale multi-model that potentially provides a new and more extensive mathematical basis for coupling classical elasticity and molecular dynamics, thus enabling next generation atomistic-to-continuum multiscale simulations. In addition, a rigorous study of nite element discretizations of peridynamics will be considered. Using the fact that peridynamics is spatially derivative free, we will also characterize the space of admissible peridynamic solutions and carry out systematic analyses of the models, in particular rigorously showing how peridynamics encompasses fracture and other failure phenomena. Additional aspects of the project include the mathematical and numerical analysis of peridynamics applied to stochastic peridynamics models. In summary, the project will make feasible mathematically consistent multiscale models for the analysis and design of advanced materials.
Numerical Model for Conduction-Cooled Current Lead Heat Loads
White, M.J.; Wang, X.L.; /Fermilab; Brueck, H.D.; /DESY
2011-06-10T23:59:59.000Z
Current leads are utilized to deliver electrical power from a room temperature junction mounted on the vacuum vessel to a superconducting magnet located within the vacuum space of a cryostat. There are many types of current leads used at laboratories throughout the world; however, conduction-cooled current leads are often chosen for their simplicity and reliability. Conduction-cooled leads have the advantage of using common materials, have no superconducting/normal state transition, and have no boil-off vapor to collect. This paper presents a numerical model for conduction-cooled current lead heat loads. This model takes into account varying material and fluid thermal properties, varying thicknesses along the length of the lead, heat transfer in the circumferential and longitudinal directions, electrical power dissipation, and the effect of thermal intercepts. The model is validated by comparing the numerical model results to ideal cases where analytical equations are valid. In addition, the XFEL (X-Ray Free Electron Laser) prototype current leads are modeled and compared to the experimental results from testing at DESY's XFEL Magnet Test Stand (XMTS) and Cryomodule Test Bench (CMTB).
Numerical Modeling of Charged Black Holes with Massive Dilaton
T. L. Boyadjiev; P. P. Fiziev
2003-11-28T23:59:59.000Z
In this paper the static, spherically symmetric and electrically charged black hole solutions in Einstein-Born-Infeld gravity with massive dilaton are investigated numerically. The Continuous Analog of Newton Method (CANM) is used to solve the corresponding nonlinear multipoint boundary value problems (BVPs). The linearized BVPs are solved numerically by means of collocation scheme of fourth order. A special class of solutions are the extremal ones. We show that the extremal horizons within the framework of the model satisfy some nonlinear system of algebraic equations. Depending on the charge $q$ and dilaton mass $\\gamma$, the black holes can have no more than three horizons. This allows us to construct some Hermite polynomial of third order. Its real roots describe the number, the type and other characteristics of the horizons.
On Numerical Considerations for Modeling Reactive Astrophysical Shocks
Papatheodore, Thomas L [ORNL] [ORNL; Messer, Bronson [ORNL] [ORNL
2014-01-01T23:59:59.000Z
Simulating detonations in astrophysical environments is often complicated by numerical approximations to shock structure. A common prescription to ensure correct detonation speeds (and associated quantities) is to prohibit burning inside the numerically broadened shock (Fryxell et al. 1989). We have performed a series of simulations to verify the efficacy of this approximation and to understand how resolution and dimensionality might affect its use. Our results show that, in one dimension, prohibiting burning in the shock is important wherever the carbon burning length is not resolved, in keeping with the results of Fryxell et al. (1989). In two dimensions, we find that the prohibition of shock burning effectively inhibits the development of cellular structure for all but the most highly-resolved cases. We discuss the possible impacts this outcome may have on sub-grid models and detonation propagation in Type Ia supernovae.
Pearce, Fred
2003-01-01T23:59:59.000Z
We use a 3-D finite difference numerical model to generate synthetic seismograms from a simple fractured reservoir
Progress report on LBL's numerical modeling studies on Cerro Prieto
Halfman-Dooley, S.E.; Lippman, M.J.; Bodvarsson, G.S.
1989-04-01T23:59:59.000Z
An exploitation model of the Cerro Prieto geothermal system is needed to assess the energy capacity of the field, estimate its productive lifetime and develop an optimal reservoir management plan. The model must consider the natural state (i.e., pre-exploitation) conditions of the system and be able to predict changes in the reservoir thermodynamic conditions (and fluid chemistry) in response to fluid production (and injection). This paper discusses the results of a three-dimensional numerical simulation of the natural state conditions of the Cerro Prieto field and compares computed and observed pressure and temperature/enthalpy changes for the 1973--1987 production period. 16 refs., 24 figs., 2 tabs.
Bhaumik, Tirtharaj
2005-11-01T23:59:59.000Z
Understanding the physics of multiphase plumes and their simulation through numerical modeling has been an important area of research in recent times in the area of environmental fluid mechanics. The two renowned numerical modeling types...
A numerical model of aerosol scavenging: Part 1, Microphysics parameterization
Molenkamp, C.R.; Bradley, M.M.
1991-09-01T23:59:59.000Z
We have developed a three-dimensional numerical model (OCTET) to simulate the dynamics and microphysics of clouds and the transport, diffusion and precipitation scavenging of aerosol particles. In this paper we describe the cloud microphysics and scavenging parameterizations. The representation of cloud microphysics is a bulk- water parameterization which includes water vapor and five types of hydrometeors (cloud droplets, rain drops, ice crystals, snow, and graupel). A parallel parameterization represents the scavenging interactions between pollutant particles and hydrometeors including collection of particles because of condensation nucleation, Brownian and phoretic attachment, and inertial capture, resuspension because of evaporation and sublimation; and transfer interactions where particles collected by one type of hydrometeor are transferred to another type of freezing, melting, accretion, riming and autoconversion.
Numerical Methods for the Bogoliubov-Tolmachev-Shirkov model in superconductivity theory
Zhihao Ge; Ruihua Li
2014-12-25T23:59:59.000Z
In the work, the numerical methods are designed for the Bogoliubov-Tolmachev-Shirkov model in superconductivity theory. The numerical methods are novel and effective to determine the critical transition temperature and approximate to the energy gap function of the above model. Finally, a numerical example confirming the theoretical results is presented.
Numerical Methods for the Bogoliubov-Tolmachev-Shirkov model in superconductivity theory
Zhihao Ge; Ruihua Li
2015-03-08T23:59:59.000Z
In the work, the numerical methods are designed for the Bogoliubov-Tolmachev-Shirkov model in superconductivity theory. The numerical methods are novel and effective to determine the critical transition temperature and approximate to the energy gap function of the above model. Finally, a numerical example confirming the theoretical results is presented.
AI-Based Simulation: An Alternative to Numerical Simulation and Modeling
Mohaghegh, Shahab
: Numerical Modeling, Simulation, Artificial Intelligence, Data Min- ing, Reservoir Modeling, Reservoir data for brown fields. The run-time of AI-Based reservoir models that provide complete field responses Computational Fluid Dynamics (CFD) to Numer- ical Reservoir Simulation (NRS) most of the computational modeling
Baudouin, Lucie
A controlled distributed parameter model for a fluid-flexible structure system: numerical consider the problem of active reduction of vibrations in a fluid-flexible structure system and the sloshing of the fuel inside the wing's tank. The control is performed using piezoelectric patches
Numerical study of energy diffusion in King models
Tom Theuns
1995-11-07T23:59:59.000Z
The energy diffusion coefficients D_n(E) (n=1,2) for a system of equal mass particles moving self-consistently in an N-body realisation of a King model are computed from the probability per unit time, P(E, Delta E), that a star with initial energy E will undergo an energy change Delta E. In turn, P is computed from the number of times during the simulation that a particle in a state of given energy undergoes a transition to another state. These particle states are defined directly from the time evolution of E by identifying them with the event occuring between two local maxima in the E(t) curve. If one assumes next that energy changes are uncorrelated between different states, one can use diffusion theory to compute D_n(E). The simulations employ N=512, 2048,... , 32768 particles and are performed using an implementation of Aarseth's direct integrator N-body1 on a massively parallel computer. The more than seven million transitions measured in the largest N simulation provide excellent statistics. The numerically determined D(E)'s are compared against their theoretical counterparts which are computed from phase-space averaged rates of energy change due to independent binary encounters. The overall agreement between them is impressive over most of the energy range, notwithstanding the very different type of approximations involved, giving considerable support to the valid usage of these theoretical expressions to simulate dynamical evolution in Fokker-Planck type calculations.
Representing Cloud Processing of Aerosol in Numerical Models
Mechem, D.B.; Kogan, Y.L.
2005-03-18T23:59:59.000Z
The satellite imagery in Figure 1 provides dramatic examples of how aerosol influences the cloud field. Aerosol from ship exhaust can serve as nucleation centers in otherwise cloud-free regions, forming ship tracks (top image), or can enhance the reflectance/albedo in already cloudy regions. This image is a demonstration of the first indirect effect, in which changes in aerosol modulate cloud droplet radius and concentration, which influences albedo. It is thought that, through the effects it has on precipitation (drizzle), aerosol can also affect the structure and persistence of planetary boundary layer (PBL) clouds. Regions of cellular convection, or open pockets of cloudiness (bottom image) are thought to be remnants of strongly drizzling PBL clouds. Pockets of Open Cloudiness (POCs) (Stevens et al. 2005) or Albrecht's ''rifts'' are low cloud fraction regions characterized by anomalously low aerosol concentrations, implying they result from precipitation. These features may in fact be a demonstration of the second indirect effect. To accurately represent these clouds in numerical models, we have to treat the coupled cloud-aerosol system. We present the following series of mesoscale and large eddy simulation (LES) experiments to evaluate the important aspects of treating the coupled cloud-aerosol problem. 1. Drizzling and nondrizzling simulations demonstrate the effect of drizzle on a mesoscale forecast off the California coast. 2. LES experiments with explicit (bin) microphysics gauge the relative importance of the shape of the aerosol spectrum on the 3D dynamics and cloud structure. 3. Idealized mesoscale model simulations evaluate the relative roles of various processes, sources, and sinks.
Modelling and Control of Activated Sludge Processes
Skogestad, Sigurd
Modelling and Control of Activated Sludge Processes Michela Mulas Dottorato di Ricerca of Activated Sludge Processes Michela Mulas Supervisors: Prof. Roberto Baratti Ing. Stefania Tronci Dottorato . . . . . . . . . . . . . . . . . . . . . . . . . 5 2 ASP Models and Simulations 7 2.1 The Activated Sludge Process
An efficient numerical terrestrial scheme (ENTS) for fast earth system modelling
Williamson, Mark
An efficient numerical terrestrial scheme (ENTS) for fast earth system modelling Mark Williamson Working Paper 83 #12;An efficient numerical terrestrial scheme (ENTS) for fast earth system modelling Mark for long time period simulations and large ensemble studies in Earth system models of intermediate
Numerical analysis of a model for Nickel-Iron alloy electrodeposition on rotating disk
Paris-Sud XI, Université de
Numerical analysis of a model for Nickel-Iron alloy electrodeposition on rotating disk electrode N the nickel-iron electrodeposition process, we have developed one-dimensional numerical model. This model ad can predict characteristic features of the nickel-iron sys- tem. this work was supported
Numerical modelling of hyperbolic conservation laws using bicharacteristics
Hanke-Bourgeois, Martin
volume methods -1- #12;Overview I. Hyperbolic Conservation Laws Theory of bicharacteristics and evolution, bicharacteritsics stability, accuracy, error analysis III. Numerical Experiments: Wave equation system, Euler eqs finite volume methods -2- #12;· airflow · hydraulic schock · meteorological flow Source: efluid
ASYMPTOTIC AND NUMERICAL MODELLING OF FLOWS IN FRACTURED POROUS MEDIA
Paris-Sud XI, Université de
numerical results are reported showing different kinds of flows in the case of impermeable or partially. Joliot Curie, F-13453 Marseille cedex 13. Email : [angot,fboyer,fhubert]@cmi.univ-mrs.fr cl EDP Sciences
Numerical Modeling of CIGS Solar Cells: Definition of the Baseline and
Sites, James R.
Thesis Numerical Modeling of CIGS Solar Cells: Definition of the Baseline and Explanation our supervision by Markus Gloeckler entitled "Numerical Modeling of CIGS Solar Cells: Definition. A three-layer structure, simulating a Cu(InGa)Se2 (CIGS) heterojunction solar cell, was set up using
NUMERICAL MODELING OF CIGS AND CdTe SOLAR CELLS: SETTING THE BASELINE
Sites, James R.
NUMERICAL MODELING OF CIGS AND CdTe SOLAR CELLS: SETTING THE BASELINE M. Gloeckler, A important complications that are often found in experimental CIGS and CdTe solar cells. 1. INTRODUCTION Numerical modeling of polycrystalline thin-film solar cells is an important strategy to test the viability
Penetration of solar radiation in the upper ocean: A numerical model for oceanic and coastal waters
Lee, Zhongping
Penetration of solar radiation in the upper ocean: A numerical model for oceanic and coastal waters in the upper ocean, the vertical distribution of solar radiation (ESR) in the shortwave domain plays (2005), Penetration of solar radiation in the upper ocean: A numerical model for oceanic and coastal
Numerical analysis of a one-dimensional elastodynamic model of dry friction and unilateral contact
Renard, Yves - Pôle de Mathématiques, Institut National des Sciences Appliquées de Lyon
.e. hyperbolic) model with dry friction. Since we consider a Coulomb friction law with a slip velocity dependentNumerical analysis of a one-dimensional elastodynamic model of dry friction and unilateral contact in the numerical analysis of more elaborated dynamic purely elastic problems with dry friction. Ó 2001 Elsevier
ON ACCURACY OF NUMERICAL EMC/EMI MODELING OVER A WIDE FREQUENCY RANGE
Loyka, Sergey
1 ON ACCURACY OF NUMERICAL EMC/EMI MODELING OVER A WIDE FREQUENCY RANGE Sergey Loyka EMC Lab: loyka@nemc.belpak.minsk.by Abstract - Numerical EMC/EMI modeling over a wide frequency range requires computational efficiency is proposed. I. INTRODUCTION Almost all the EMC problems are wide frequency range ones
Numerical modeling of short pulse laser interaction with Au nanoparticle surrounded by water
Zhigilei, Leonid V.
Numerical modeling of short pulse laser interaction with Au nanoparticle surrounded by water Alexey, University of Virginia, USA Available online 3 February 2007 Abstract Short pulse laser interaction modeling; Nanoparticles; Cell targeting; Laser damage 1. Introduction Short pulse laser irradiation
Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part I: Numerical Modeling
Xu, Xianfan
Thermoelectric Generators for Automotive Waste Heat Recovery Systems Part I: Numerical Modeling (TEG) designed for automotive waste heat recovery systems. This model is capable of computing bismuth telluride are considered for thermoelectric modules (TEMs) for conversion of waste heat from
Numerical Model of a Tensioner System and Flex Joint
Huang, Han
2013-07-27T23:59:59.000Z
Top Tensioned Riser (TTR) and Steel Catenary Riser (SCR) are often used in a floating oil/gas production system deployed in deep water for oil transport. This study focuses on the improvements to the existing numerical code, known as CABLE3D...
Numerical Modeling of Human Effect on Indoor Propagation
Paris-Sud XI, Université de
several types of obstacles such a brick enclosure walls, one metal heater, two metal wardrobes, two metal antenna placed 85 cm above the floor level. The spatial step is /10, or is the wavelength, chosen by the numerical dispersions. The choice of the spatial step is a compromise between the minimization of inaccuracy
Numerical modelling of a radio-frequency micro ion thruster
Tsay, Michael Meng-Tsuan
2006-01-01T23:59:59.000Z
A simple performance model is developed for an inductively-coupled radio-frequency micro ion thruster. Methods of particle and energy balance are utilized for modeling the chamber plasma discharge. A transformer model is ...
Qidwai, Muhammad Abu Bakar Siddiq
1995-01-01T23:59:59.000Z
', it transforms into self-accommodated martensite (no net transformation strain). Subsequent application of load isothermally causes the reorientation of martensitic variants resulting in a net transformation strain. This strain, which remains on unloading...-dimensional thermomechanical SMA response. However, not much work is reported in regard to the numerical implementation of three dimensional formulation of shape memory alloy constitutive models. The implementation itself is not fundamentally different fiom any inelastic...
Fractional Calculus in Hydrologic Modeling: A Numerical Perspective
David A. Benson; Mark M. Meerschaert; Jordan Revielle
2012-01-01T23:59:59.000Z
Fractional derivatives can be viewed either as a handy extension of classical calculus or, more deeply, as mathematical operators defined by natural phenomena. This follows the view that the diffusion equation is defined as the governing equation of a Brownian motion. In this paper, we emphasize that fractional derivatives come from the governing equations of stable Levy motion, and that fractional integration is the corresponding inverse operator. Fractional integration, and its multi-dimensional extensions derived in this way, are intimately tied to fractional Brownian (and Levy) motions and noises. By following these general principles, we discuss the Eulerian and Lagrangian numerical solutions to fractional partial differential equations, and Eulerian methods for stochastic integrals. These numerical approximations illuminate the essential nature of the fractional calculus.
Numerical modeling of geothermal systems with applications to Krafla, Iceland and Olkaria, Kenya
Bodvarsson, G.S.
1987-08-01T23:59:59.000Z
The use of numerical models for the evaluation of the generating potential of high temperature geothermal fields has increased rapidly in recent years. In the present paper a unified numerical approach to the modeling of geothermal systems is discussed and the results of recent modeling of the Krafla geothermal field in Iceland and the Olkaria, Kenya, are described. Emphasis is placed on describing the methodology using examples from the two geothermal fields.
Numerical modeling of magnetohydrodynamic activity in the Swarthmore Spheromak Experiment
Brown, Michael R.
simulation data will be used as input for a particle orbit and energization code. © 2001 American Institute of Physics. DOI: 10.1063/1.1362294 I. OVERVIEW There are several unresolved mysteries related to solar and astrophysical magnetism. First is the origin of solar and astrophysical magnetic fields: the dynamo problem
Numerical simulation of a lattice polymer model at its integrable point
A. Bedini; A. L. Owczarek; T. Prellberg
2013-05-21T23:59:59.000Z
We revisit an integrable lattice model of polymer collapse using numerical simulations. This model was first studied by Bl\\"ote and Nienhuis in J. Phys. A. {\\bf 22}, 1415 (1989) and it describes polymers with some attraction, providing thus a model for the polymer collapse transition. At a particular set of Boltzmann weights the model is integrable and the exponents $\
Bürger, Raimund
-dimensional model of sedimentation of suspensions of small solid particles dispersed in a viscous fluid. This model accepted spatially one-dimensional sedimentation model [35] gives rise to one scalar, nonlinear hyperbolicINTERNATIONAL JOURNAL OF c 2011 Institute for Scientific NUMERICAL ANALYSIS AND MODELING Computing
Bürger, Raimund
-dimensional model of sedimentation of suspensions of small solid particles dispersed in a viscous fluid. This model accepted spatially one-dimensional sedimentation model [35] gives rise to one scalar, nonlinear hyperbolicINTERNATIONAL JOURNAL OF c 2012 Institute for Scientific NUMERICAL ANALYSIS AND MODELING Computing
Numerical modeling of wave propagation in random anisotropic heterogeneous elastic media
Boyer, Edmond
Numerical modeling of wave propagation in random anisotropic heterogeneous elastic media Q.-A. Ta numerical experiments that were performed on wave propagation in a randomly generated anisotropic used for the propagation of waves in geophysical media are not compatible with the surface recordings
Chen, Qingyan "Yan"
. "Improvements on FFD modeling by using different numerical schemes," Numerical Heat Transfer, Part B (m) t time step (s) Greek Symbols ratio of mass flow rate to a flow domain over that out of the flow: Fundamentals, 58(1), 1-16. #12;2 Abstract Indoor environm ent design and air m anagement in buildings requires
Numerical models of caldera deformation: Effects of multiphase and multicomponent hydrothermal studies addressing the effects of multiphase flow on crustal mechanics have been attempted. Recent numerical simulations of multiphase (liquid-gas), multicomponent (H2OÂCO2) hydrothermal fluid flow
USING LEARNING MACHINES TO CREATE SOLAR RADIATION MAPS FROM NUMERICAL WEATHER PREDICTION MODELS,
Paris-Sud XI, UniversitÃ© de
USING LEARNING MACHINES TO CREATE SOLAR RADIATION MAPS FROM NUMERICAL WEATHER PREDICTION MODELS to develop a methodology to generate solar radiation maps using information from different sources. First with conclusions and next works in the last section. Keywords: Solar Radiation maps, Numerical Weather Predictions
Analytical-Numerical Modeling Of Komatiite Lava Emplacement And...
Modeling Of Komatiite Lava Emplacement And Thermal Erosion At Perseverance, Western Australia Jump to: navigation, search OpenEI Reference LibraryAdd to library...
Numerical modeling of elastic wave scattering by near-surface heterogeneities
Al Muhaidib, Abdulaziz
2013-01-01T23:59:59.000Z
A perturbation method for elastic waves and numerical forward modeling are used to calculate the effects of seismic wave scattering from arbitrary shape shallow subsurface heterogeneities. Wave propagation is simulated ...
2D-Modelling of pellet injection in the poloidal plane: results of numerical tests
Paris-Sud XI, UniversitÃ© de
2D-Modelling of pellet injection in the poloidal plane: results of numerical tests P. Lalousis developed for computing the expansion of pellet-produced clouds in the poloidal plane. The expansion
Seismic scattering attributes to estimate reservoir fracture density : a numerical modeling study
Pearce, Frederick D. (Frederick Douglas), 1978-
2003-01-01T23:59:59.000Z
We use a 3-D finite difference numerical model to generate synthetic seismograms from a simple fractured reservoir containing evenly-spaced, discrete, vertical fracture zones. The fracture zones are represented using a ...
Seismic Scattering Attributes to Estimate Reservoir Fracture Density: A Numerical Modeling Study
Pearce, Frederick Douglas
We use a 3-D finite difference numerical model to generate synthetic seismograms from a simple fractured reservoir containing evenly-spaced, discrete, vertical fracture zones. The fracture zones are represented using a ...
Ravago Bastardo, Delmira Cristina
2005-08-29T23:59:59.000Z
The main objective of this research is to compare the performance of cyclic steam injection using horizontal wells based on the analytical model developed by Gunadi against that based on numerical simulation. For comparison, ...
Numerically Estimating Internal Models of Dynamic Virtual Objects
Sekuler, Robert
human subjects to manipulate a computer-animated virtual object. This virtual object (vO) was a high, human cognition, human information processing, ideal performer, internal model, virtual object, virtual, specifically how humans acquire an internal model of a dynamic virtual object. Our methodology minimizes
Giovanni Noselli; Antonio DeSimone
2014-08-26T23:59:59.000Z
We present experimental and numerical results for a model crawler which is able to extract net positional changes from reciprocal shape changes, i.e. 'breathing-like' deformations, thanks to directional, frictional interactions with a textured solid substrate, mediated by flexible inclined feet. We also present a simple reduced model that captures the essential features of the kinematics and energetics of the gait, and compare its predictions with the results from experiments and from numerical simulations.
NUMERICAL MODELING OF TURBULENT FLOW IN A COMBUSTION TUNNEL
Ghoniem, A.F.
2013-01-01T23:59:59.000Z
1VJcDona·ld, H. (1979) Combustion r 1 iodeJ·ing in Two and1979) Practical Turbulent-Combustion Interaction Models forInternation on Combustors. Combustion The 17th Symposium
Numerical Modeling of Hydraulic Fracturing in Oil Sands
2008-11-16T23:59:59.000Z
A thermal hydro-mechanical fracture nite element model is developed, which is able to ..... c) Fluid velocity: Darcy's law, in general index form, is given by: vi = Kij.
Numerical Modeling of Seafloor Interation with Steel Catenary Riser
You, Jung Hwan
2012-10-19T23:59:59.000Z
degradation it is possible to simulate the trench formation process and estimate deflections and moments along the riser length. The seabed model is used to perform parametric studies to assess the effects of stiffness, soil strength, amplitude of pipe...
Ductile fracture modeling : theory, experimental investigation and numerical verification
Xue, Liang, 1973-
2007-01-01T23:59:59.000Z
The fracture initiation in ductile materials is governed by the damaging process along the plastic loading path. A new damage plasticity model for ductile fracture is proposed. Experimental results show that fracture ...
Numerically Efficient Water Quality Modeling and Security Applications
Mann, Angelica
2013-02-04T23:59:59.000Z
utilities protect the public against potential contamination events. The first component is a novel water quality modeling framework referred to as Merlion. The linear system describing contaminant spread through the network at the core of Merlion provides...
Efficient Dynamic Modeling, Numerical Optimal Control and Experimental Results for Various Gaits
Stryk, Oskar von
Efficient Dynamic Modeling, Numerical Optimal Control and Experimental Results for Various Gaits. A fully three- dimensional dynamical model of Sony's four-legged robot is used to state an optimal control model and the algorithm for evaluating the dynamics. The formulation of the optimal control problem
Author's personal copy A new 3D numerical model of cosmogenic nuclide 10
Usoskin, Ilya G.
Author's personal copy A new 3D numerical model of cosmogenic nuclide 10 Be production's atmosphere cosmogenic isotopes A new quantitative model of production of the cosmogenic isotope 10 solar energetic particle events. The model was tested against the results of direct measurements
Numerical Experiments of Some Krylov Subspace Methods for Black Oil Model
Lai, Choi-Hong
Numerical Experiments of Some Krylov Subspace Methods for Black Oil Model Jianwen Cao #3; Choi of linear systems originated from the black oil model in oil reservoir simulation. There exists some Krylov subspace algorithms and pre- conditioning techniques for the black oil model as appeared in the literature
Adegbesan, K.O.; Donnelly, J.K.; Moore, R.G.; Bennion, D.W.
1986-08-01T23:59:59.000Z
Multiresponse kinetic models are established for the low-temperature oxidation (LTO) reaction of Athabasca oil sands bitumen. The models provide adequate description of the overall rate of oxygen consumption and of the reactions of the liquid phase bitumen components. The LTO models are suitable for use in the in situ combustion numerical simulators of oil sands.
A CONSISTENT MODELLING METHODOLOGY FOR SECONDARY1 SETTLING TANKS: A RELIABLE NUMERICAL METHOD2
Bürger, Raimund
relations for hindered settling, compression and dispersion can be used within the model, allowing the user, continuous sedimentation, secondary clarifier, simulation5 model, partial differential equation6 NomenclatureA CONSISTENT MODELLING METHODOLOGY FOR SECONDARY1 SETTLING TANKS: A RELIABLE NUMERICAL METHOD2
Xing, Lu [Oklahoma State University; Cullin, James [Oklahoma State University; Spitler, Jeffery [Oklahoma State University; Im, Piljae [ORNL; Fisher, Daniel [Oklahoma State University
2011-01-01T23:59:59.000Z
A new type of ground heat exchanger that utilizes the excavation often made for basements or foundations has been proposed as an alternative to conventional ground heat exchangers. This article describes a numerical model that can be used to size these foundation heat exchanger (FHX) systems. The numerical model is a two-dimensional finite-volume model that considers a wide variety of factors, such as soil freezing and evapotranspiration. The FHX numerical model is validated with one year of experimental data collected at an experimental house located near Oak Ridge, Tennessee. The model shows good agreement with the experimental data-heat pump entering fluid temperatures typically within 1 C (1.8 F) - with minor discrepancies due to approximations, such as constant moisture content throughout the year, uniform evapotranspiration over the seasons, and lack of ground shading in the model.
IMPROVED NUMERICAL METHODS FOR MODELING RIVER-AQUIFER INTERACTION.
Tidwell, Vincent C.; Sue Tillery; Phillip King
2008-09-01T23:59:59.000Z
A new option for Local Time-Stepping (LTS) was developed to use in conjunction with the multiple-refined-area grid capability of the U.S. Geological Survey's (USGS) groundwater modeling program, MODFLOW-LGR (MF-LGR). The LTS option allows each local, refined-area grid to simulate multiple stress periods within each stress period of a coarser, regional grid. This option is an alternative to the current method of MF-LGR whereby the refined grids are required to have the same stress period and time-step structure as the coarse grid. The MF-LGR method for simulating multiple-refined grids essentially defines each grid as a complete model, then for each coarse grid time-step, iteratively runs each model until the head and flux changes at the interfacing boundaries of the models are less than some specified tolerances. Use of the LTS option is illustrated in two hypothetical test cases consisting of a dual well pumping system and a hydraulically connected stream-aquifer system, and one field application. Each of the hypothetical test cases was simulated with multiple scenarios including an LTS scenario, which combined a monthly stress period for a coarse grid model with a daily stress period for a refined grid model. The other scenarios simulated various combinations of grid spacing and temporal refinement using standard MODFLOW model constructs. The field application simulated an irrigated corridor along the Lower Rio Grande River in New Mexico, with refinement of a small agricultural area in the irrigated corridor.The results from the LTS scenarios for the hypothetical test cases closely replicated the results from the true scenarios in the refined areas of interest. The head errors of the LTS scenarios were much smaller than from the other scenarios in relation to the true solution, and the run times for the LTS models were three to six times faster than the true models for the dual well and stream-aquifer test cases, respectively. The results of the field application show that better estimates of daily stream leakage can be made with the LTS simulation, thereby improving the efficiency of daily operations for an agricultural irrigation system. ACKNOWLEDGEMENTSThe authors appreciatively acknowledge support for Sue Tillery provided by Sandia National Laboratories' through a Campus Executive Laboratory Directed Research and Development (LDRD) research project.Funding for this study was provided by Directed Research and Development (LDRD) research project.
Numerical Integration Numerical Summation
Cohen, Henri
Numerical Integration Numerical Summation Numerical Extrapolation Numerical Recipes for Multiprecision Computations #12;Numerical Integration Numerical Summation Numerical Extrapolation Multiprecision, integration, summation, extrapolation, evaluation of continued fractions, Euler products and sums, complete
Lattice Percolation Approach to Numerical Modeling of Tissue Aging
Privman, Vladimir; Libert, Sergiy
2015-01-01T23:59:59.000Z
We describe a percolation-type approach to modeling of the processes of aging and certain other properties of tissues analyzed as systems consisting of interacting cells. Tissues are considered as structures made of regular healthy, senescent, dead (apoptotic) cells, and studied dynamically, with the ongoing processes including regular cell division to fill vacant sites left by dead cells, healthy cells becoming senescent or dying, and other processes. Statistical-mechanics description can provide patterns of time dependence and snapshots of morphological system properties. An illustrative application of the developed theoretical modeling approach is reported, confirming recent experimental findings that inhibition of senescence can lead to extended lifespan.
Numerical modeling of an all vanadium redox flow battery.
Clausen, Jonathan R.; Brunini, Victor E.; Moffat, Harry K.; Martinez, Mario J.
2014-01-01T23:59:59.000Z
We develop a capability to simulate reduction-oxidation (redox) flow batteries in the Sierra Multi-Mechanics code base. Specifically, we focus on all-vanadium redox flow batteries; however, the capability is general in implementation and could be adopted to other chemistries. The electrochemical and porous flow models follow those developed in the recent publication by [28]. We review the model implemented in this work and its assumptions, and we show several verification cases including a binary electrolyte, and a battery half-cell. Then, we compare our model implementation with the experimental results shown in [28], with good agreement seen. Next, a sensitivity study is conducted for the major model parameters, which is beneficial in targeting specific features of the redox flow cell for improvement. Lastly, we simulate a three-dimensional version of the flow cell to determine the impact of plenum channels on the performance of the cell. Such channels are frequently seen in experimental designs where the current collector plates are borrowed from fuel cell designs. These designs use a serpentine channel etched into a solid collector plate.
EFFICIENT NUMERICAL SOLUTION TECHNIQUES IN COMPOSITION MODEL 1
on the reservoir pressure and saturation pressure. A blackÂoil model works well in simulating the waterflooding The objective of reservoir simulation is to understand the complex chemical, physical, and fluid flow processes occurring in a petroleum reservoir sufficiently well to be able to optimize the recovery of hydrocarbon
Numerical Modeling At Coso Geothermal Area (1995) | Open Energy Information
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer PlantMunhall,Missouri: EnergyExcellence Seed LLCShores,ActivityNufcor
Numerical Modeling At Dixie Valley Geothermal Area (Benoit, 1999) | Open
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer PlantMunhall,Missouri: EnergyExcellence Seed LLCShores,ActivityNufcorEnergy Information
Numerical Modeling At Dixie Valley Geothermal Area (Iovenitti, Et Al.,
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer PlantMunhall,Missouri: EnergyExcellence Seed LLCShores,ActivityNufcorEnergy
Numerical Modeling At Raft River Geothermal Area (1983) | Open Energy
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer PlantMunhall,Missouri: EnergyExcellence Seed LLCShores,ActivityNufcorEnergy2003)
Numerical Modeling of Transient Basin and Range Extensional Geothermal
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer PlantMunhall,Missouri: EnergyExcellence Seed LLCShores,ActivityNufcorEnergy2003)Systems |
Numerical Modelling of Geothermal Systems a Short Introduction | Open
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer PlantMunhall,Missouri: EnergyExcellence Seed LLCShores,ActivityNufcorEnergy2003)Systems
Modeling Temporal Activity Patterns in Dynamic Social Networks
Raghavan, Vasanthan; Galstyan, Aram; Tartakovsky, Alexander G
2013-01-01T23:59:59.000Z
The focus of this work is on developing probabilistic models for user activity in social networks by incorporating the social network influence as perceived by the user. For this, we propose a coupled Hidden Markov Model, where each user's activity evolves according to a Markov chain with a hidden state that is influenced by the collective activity of the friends of the user. We develop generalized Baum-Welch and Viterbi algorithms for model parameter learning and state estimation for the proposed framework. We then validate the proposed model using a significant corpus of user activity on Twitter. Our numerical studies show that with sufficient observations to ensure accurate model learning, the proposed framework explains the observed data better than either a renewal process-based model or a conventional uncoupled Hidden Markov Model. We also demonstrate the utility of the proposed approach in predicting the time to the next tweet. Finally, clustering in the model parameter space is shown to result in dist...
Joint physical and numerical modeling of water distribution networks.
Zimmerman, Adam; O'Hern, Timothy John; Orear, Leslie Jr.; Kajder, Karen C.; Webb, Stephen Walter; Cappelle, Malynda A.; Khalsa, Siri Sahib; Wright, Jerome L.; Sun, Amy Cha-Tien; Chwirka, J. Benjamin; Hartenberger, Joel David; McKenna, Sean Andrew; van Bloemen Waanders, Bart Gustaaf; McGrath, Lucas K.; Ho, Clifford Kuofei
2009-01-01T23:59:59.000Z
This report summarizes the experimental and modeling effort undertaken to understand solute mixing in a water distribution network conducted during the last year of a 3-year project. The experimental effort involves measurement of extent of mixing within different configurations of pipe networks, measurement of dynamic mixing in a single mixing tank, and measurement of dynamic solute mixing in a combined network-tank configuration. High resolution analysis of turbulence mixing is carried out via high speed photography as well as 3D finite-volume based Large Eddy Simulation turbulence models. Macroscopic mixing rules based on flow momentum balance are also explored, and in some cases, implemented in EPANET. A new version EPANET code was developed to yield better mixing predictions. The impact of a storage tank on pipe mixing in a combined pipe-tank network during diurnal fill-and-drain cycles is assessed. Preliminary comparison between dynamic pilot data and EPANET-BAM is also reported.
Avedisian, C. T. (Cornell University, Ithaca, NY); Presser, Cary (National Institute of Standard & Technology, Gaithersburg, MD); DesJardin, Paul Edward (University at Buffalo, New York, NY); Hewson, John C.; Yoon, Sam Sukgoo
2005-03-01T23:59:59.000Z
This study compares experimental measurements and numerical simulations of liquid droplets over heated (to a near surface temperature of 423 K) and unheated cylinders. The numerical model is based on an unsteady Reynolds-averaged Navier-Stokes (RANS) formulation using a stochastic separated flow (SSF) approach for the droplets that includes submodels for droplet dispersion, heat and mass transfer, and impact on a solid surface. The details of the droplet impact model are presented and the model is used to simulate water spray impingement on a cylinder. Computational results are compared with experimental measurements using phase Doppler interferometry (PDI).
Semi-distributed lumped model of a karst system under active1 management2
Paris-Sud XI, UniversitÃ© de
system27 28 Keywords29 Impulse response30 Groundwater flow modeling31 Groundwater level fluctuations32 Pumping33 Introduction34 Numerical models for karst aquifers usually fall within two main categories1 Semi-distributed lumped model of a karst system under active1 management2 Bernard LADOUCHE1
A Numerical Model for the Dynamic Simulation of a Recirculation Single-Effect Absorption Chiller
Paris-Sud XI, UniversitÃ© de
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 is developed. The chiller is driven by two distinct heat sources, includes a custom integrated falling film
URBAN AEROSOLS SURVEY USING LIDAR AND NUMERICAL MODEL S. GEFFROY1
Boyer, Edmond
URBAN AEROSOLS SURVEY USING LIDAR AND NUMERICAL MODEL S. GEFFROY1 , L. SOULHAC2 , E. FREJAFON3 , R technologique ALATA BP2, F-60550 Verneuil-en-Halatte, France. Keywords: LIDAR, URBAN AEROSOLS, MODEL, IMPACT SURVEY. INTRODUCTION The impact of particulate matters and aerosols on environment and on radiative
Numerical methods for vector Stefan models of solid-state alloys
Vuik, Kees
-called aluminium-based alloys. Subsequently, the obtained alloy is cast into a mould where it solidifies. DuringNumerical methods for vector Stefan models of solid-state alloys PROEFSCHRIFT ter verkrijging van for vector Stefan models of solid-state alloys. Dissertation at Delft University of Technology. Copyright c
NUMERICAL MODELING OF SHOCK-INDUCED DAMAGE FOR GRANITE UNDER DYNAMIC LOADING
Stewart, Sarah T.
NUMERICAL MODELING OF SHOCK-INDUCED DAMAGE FOR GRANITE UNDER DYNAMIC LOADING H. A. Ai1 , T. J beneath impact crater in granite. Model constants are determined either directly from static uniaxial from Century Dynamics to simulate the shock-induced damage in granite targets impacted by projectiles
Gracie, Robert
PeerReview Only An XFEM Model for Carbon Sequestration Journal: International Journal for Numerical method, Carbon Sequestration, Multiphase flow, XFEM, Multifield systems, Petrov-Galerkin httpScience (www.interscience.wiley.com). DOI: 10.1002/nme An XFEM Model for Carbon Sequestration Chris Ladubec
Nick, F. M.; van der Veen, Cornelis J.; Oerlemans, J.
2007-07-11T23:59:59.000Z
A one-dimensional numerical ice flow model is used to study the advance of a tidewater glacier into deep water. Starting with ice-free conditions, the model simulates glacier growth at higher elevations followed by advance on land to the head...
FOUNDATION, ANALYSIS, AND NUMERICAL INVESTIGATION OF A VARIATIONAL NETWORK-BASED MODEL FOR RUBBER
Boyer, Edmond
FOUNDATION, ANALYSIS, AND NUMERICAL INVESTIGATION OF A VARIATIONAL NETWORK-BASED MODEL FOR RUBBER, many models based on polymer chain statistics have been proposed to describe rubber elasticity. Recently, Alicandro, Cicalese, and the first author rigorously derived a continuum theory of rubber
NUMERICAL SOLUTION OF RESERVOIR FLOW MODELS BASED ON LARGE TIME STEP OPERATOR SPLITTING ALGORITHMS
processes. A black-oil model is commonly used to describe water injection. This model works well. Special focus is posed on the numerical solution algorithms for the saturation equation, which is a convection dominated, degenerate convection-di#11;usion equation. Both theory and applications are discussed
A Model and Numerical Framework for the Simulation of Solid-Solid Phase Transformations
Govindjee, Sanjay
A Model and Numerical Framework for the Simulation of Solid-Solid Phase Transformations Garrett J computational realization for the simulation of solid-solid phase transformations of the type observed in shape physical experiments and is indicative of the power of the proposed modelling methodology. In particular
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow
Boyer, Edmond
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S modeling of the turbulent flow in a rotor-stator cavity subjected to a superimposed throughflow with heat the dynamical effects from the heat transfer process. The fluid flow in an enclosed disk system with axial
MODELING AND ADAPTIVE NUMERICAL TECHNIQUES FOR OXI-DATION OF CERAMIC COMPOSITES
Adjerid, Slimane
. INTRODUCTION Oxidation shortens the life of ceramic matrix composites by, e.g., chang- ing the elasticMODELING AND ADAPTIVE NUMERICAL TECHNIQUES FOR OXI- DATION OF CERAMIC COMPOSITES S. Adjerid, M. Ai of thermal or other loading may expose the matrix and bers to hostile envi- ronments. We present a model
Numerical Modeling of Nonlinear Surface Waves caused by Surface Effect Ships Dynamics and Kinematics
Grilli, StÃ©phan T.
Numerical Modeling of Nonlinear Surface Waves caused by Surface Effect Ships Dynamics and Kinematics Hong Gun SungÂ½ and Stephan T. GrilliÂ¾ Â½ Korea Ocean Research and Development Institute, Daejeon model fully nonlinear free surface waves caused by a translating dis- turbance made of a pressure patch
Concrete calcium leaching at variable temperature: experimental data and numerical model inverse
Paris-Sud XI, UniversitÃ© de
, concrete porous solution is very basic (pH around 13) and several ionic species are highly concentrated [1Concrete calcium leaching at variable temperature: experimental data and numerical model inverse/DSU/SSIAD/BERIS, Fontenay-aux-Roses, France Abstract A simplified model for calcium leaching in concrete is presented
Numerical modeling of response of monolithic and bilayer plates to impulsive loads
Nemat-Nasser, Sia
-receiving side) amplifies the initial shock loading and thereby enhances the destructive effect of the blast modeling FEM analysis Metal-elastomer adhesion Numerical blast modeling a b s t r a c t In this paper, we in the latter case the pressure effects. Comparing the simulation and the experimental results, we focus
Bornemann, Jens
, 217Â229 (1997) SPECTRAL-DOMAIN MODELLING OF SUPERCONDUCTING MICROSTRIP STRUCTURES smain amari with available data to document the validity of the approach. Â© 1997 by John Wiley & Sons, Ltd. Int. J. Numer. Model., 10, 217Â229 (1997) No. of Figures: 9. No. of Tables: 0. No. of References: 18. 1. INTRODUCTION
d'OrlÃ©ans, UniversitÃ©
processes widely used in chemical engineering: distillation and chromatography. Distillation is a wellNumerical comparison between relaxation and nonlinear equilibrium models. Application to chemical engineering. F. James 1 M. Postel 2 M. Sep'ulveda 3 Abstract A model to take into account the finite exchange
Numerical modeling of fiber lasers with long and ultra-long ring cavity
Turitsyn, Sergei K.
Numerical modeling of fiber lasers with long and ultra-long ring cavity I.A. Yarutkina,1,2, O. S. Kobtsev, S. Kukarin, and Y. Fedotov, "Ultra-low repetition rate mode-locked fiber laser with high highlight two important aspects related to a mathematical modeling of pulsed fiber lasers with long
A consistent modelling methodology for secondary settling tanks: a reliable numerical method
Bürger, Raimund
accounting for sediment compressibility, and a dispersion term for turbulence. In addition, the solutionA consistent modelling methodology for secondary settling tanks: a reliable numerical method modelling methodology for secondary settling tanks (SSTs) leads to a partial differential equation (PDE
Active Appearance Models for Face Recognition
Bhulai, Sandjai
the performance and the computational speed of Active Appearance Models. #12;4 #12;5 Acknowledgements This paper to recognize faces, there are some difficulties to overcome. Faces are highly variable, deformable objects Appearance Model . . . . . . . . . . . . . . . . 18 2.4 The Active Appearance Search Algorithm
Incorporation of the capillary hysteresis model HYSTR into the numerical code TOUGH
Niemi, A.; Bodvarsson, G.S.; Pruess, K.
1991-11-01T23:59:59.000Z
As part of the work performed to model flow in the unsaturated zone at Yucca Mountain Nevada, a capillary hysteresis model has been developed. The computer program HYSTR has been developed to compute the hysteretic capillary pressure -- liquid saturation relationship through interpolation of tabulated data. The code can be easily incorporated into any numerical unsaturated flow simulator. A complete description of HYSTR, including a brief summary of the previous hysteresis literature, detailed description of the program, and instructions for its incorporation into a numerical simulator are given in the HYSTR user`s manual (Niemi and Bodvarsson, 1991a). This report describes the incorporation of HYSTR into the numerical code TOUGH (Transport of Unsaturated Groundwater and Heat; Pruess, 1986). The changes made and procedures for the use of TOUGH for hysteresis modeling are documented.
Blackman, Jonathan; Galley, Chad R; Szilagyi, Bela; Scheel, Mark A; Tiglio, Manuel; Hemberger, Daniel A
2015-01-01T23:59:59.000Z
Simulating a binary black hole coalescence by solving Einstein's equations is computationally expensive, requiring days to months of supercomputing time. In this paper, we construct an accurate and fast-to-evaluate surrogate model for numerical relativity (NR) waveforms from non-spinning binary black hole coalescences with mass ratios from $1$ to $10$ and durations corresponding to about $15$ orbits before merger. Our surrogate, which is built using reduced order modeling techniques, is distinct from traditional modeling efforts. We find that the full multi-mode surrogate model agrees with waveforms generated by NR to within the numerical error of the NR code. In particular, we show that our modeling strategy produces surrogates which can correctly predict NR waveforms that were {\\em not} used for the surrogate's training. For all practical purposes, then, the surrogate waveform model is equivalent to the high-accuracy, large-scale simulation waveform but can be evaluated in a millisecond to a second dependin...
Characterization of Texas lignite and numerical modeling of its in-situ gasification
Wang, Yih-Jy
1983-01-01T23:59:59.000Z
Modeling Site selection for in-situ gasification projects normally involves application of site screen1ng criteria. Some of these cr1teria were discussed by Russell et al. (1983). Numerical simulation may play an important role in s1te selection...CHARACTERIZATION OF TEXAS LIGNITE AND NUMERICAL MODELING OF ITS IN-SITU GASIFICATION A Thesis by YIH-JY WANG Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER...
The numerical solution of a nickel-cadmium battery cell model using the method of lines
Hailu, Teshome
1990-01-01T23:59:59.000Z
THE NUMERICAL SOLUTION OF A NICKEL-CADMIUM BATTERY CELL MODEL USING THE METHOD OF LINES A Thesis by TESHOME HAILU Submitted to the Office of Graduate Studies Texas Adi:M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE December 1990 Major Subject: Chemical Engineering THE NUMERICAL SOLUTION OF A NICKEL-CADMIUM BATTERY CELL MODEL USING THE METHOD OF LINES A Thesis by TESHOME HAILU Approved as to style and content by: Ralph E. White (Chairman...
Proceedings of the Numerical Modeling for Underground Nuclear Test Monitoring Symposium
Taylor, S.R.; Kamm, J.R. [eds.
1993-11-01T23:59:59.000Z
The purpose of the meeting was to discuss the state-of-the-art in numerical simulations of nuclear explosion phenomenology with applications to test ban monitoring. We focused on the uniqueness of model fits to data, the measurement and characterization of material response models, advanced modeling techniques, and applications of modeling to monitoring problems. The second goal of the symposium was to establish a dialogue between seismologists and explosion-source code calculators. The meeting was divided into five main sessions: explosion source phenomenology, material response modeling, numerical simulations, the seismic source, and phenomenology from near source to far field. We feel the symposium reached many of its goals. Individual papers submitted at the conference are indexed separately on the data base.
Bruneau, Steve
in Pack Ice Roelof C. Dragt Offshore Engineering Faculty of Mechanical, Maritime and Material Engineering of experiments to validate a Graphics Processing Unit based numerical modelling of ship operations in 2D pack ice interaction, 2D Model Experiments, Image Processing. I. INTRODUCTION A ship travelling through pack ice
:,; Abbott, B P; Abbott, R; Abbott, T; Abernathy, M R; Accadia, T; Acernese, F; Ackley, K; Adams, C; Adams, T; Addesso, P; Adhikari, R X; Affeldt, C; Agathos, M; Aggarwal, N; Aguiar, O D; Ain, A; Ajith, P; Alemic, A; Allen, B; Allocca, A; Amariutei, D; Andersen, M; Anderson, R; Anderson, S B; Anderson, W G; Arai, K; Araya, M C; Arceneaux, C; Areeda, J; Aston, S M; Astone, P; Aufmuth, P; Aulbert, C; Austin, L; Aylott, B E; Babak, S; Baker, P T; Ballardin, G; Ballmer, S W; Barayoga, J C; Barbet, M; Barish, B C; Barker, D; Barone, F; Barr, B; Barsotti, L; Barsuglia, M; Barton, M A; Bartos, I; Bassiri, R; Basti, A; Batch, J C; Bauchrowitz, J; Bauer, Th S; Behnke, B; Bejger, M; Beker, M G; Belczynski, C; Bell, A S; Bell, C; Bergmann, G; Bersanetti, D; Bertolini, A; Betzwieser, J; Beyersdorf, P T; Bilenko, I A; Billingsley, G; Birch, J; Biscans, S; Bitossi, M; Bizouard, M A; Black, E; Blackburn, J K; Blackburn, L; Blair, D; Bloemen, S; Blom, M; Bock, O; Bodiya, T P; Boer, M; Bogaert, G; Bogan, C; Bond, C; Bondu, F; Bonelli, L; Bonnand, R; Bork, R; Born, M; Boschi, V; Bose, Sukanta; Bosi, L; Bradaschia, C; Brady, P R; Braginsky, V B; Branchesi, M; Brau, J E; Briant, T; Bridges, D O; Brillet, A; Brinkmann, M; Brisson, V; Brooks, A F; Brown, D A; Brown, D D; Brückner, F; Buchman, S; Bulik, T; Bulten, H J; Buonanno, A; Burman, R; Buskulic, D; Buy, C; Cadonati, L; Cagnoli, G; Bustillo, J Calderón; Calloni, E; Camp, J B; Campsie, P; Cannon, K C; Canuel, B; Cao, J; Capano, C D; Carbognani, F; Carbone, L; Caride, S; Castiglia, A; Caudill, S; Cavaglià, M; Cavalier, F; Cavalieri, R; Celerier, C; Cella, G; Cepeda, C; Cesarini, E; Chakraborty, R; Chalermsongsak, T; Chamberlin, S J; Chao, S; Charlton, P; Chassande-Mottin, E; Chen, X; Chen, Y; Chincarini, A; Chiummo, A; Cho, H S; Chow, J; Christensen, N; Chu, Q; Chua, S S Y; Chung, S; Ciani, G; Clara, F; Clark, J A; Cleva, F; Coccia, E; Cohadon, P -F; Colla, A; Collette, C; Colombini, M; Cominsky, L; Constancio, M; Conte, A; Cook, D; Corbitt, T R; Cordier, M; Cornish, N; Corpuz, A; Corsi, A; Costa, C A; Coughlin, M W; Coughlin, S; Coulon, J -P; Countryman, S; Couvares, P; Coward, D M; Cowart, M; Coyne, D C; Coyne, R; Craig, K; Creighton, J D E; Crowder, S G; Cumming, A; Cunningham, L; Cuoco, E; Dahl, K; Canton, T Dal; Damjanic, M; Danilishin, S L; D'Antonio, S; Danzmann, K; Dattilo, V; Daveloza, H; Davier, M; Davies, G S; Daw, E J; Day, R; Dayanga, T; Debreczeni, G; Degallaix, J; Deléglise, S; Del Pozzo, W; Denker, T; Dent, T; Dereli, H; Dergachev, V; De Rosa, R; DeRosa, R T; DeSalvo, R; Dhurandhar, S; Díaz, M; Di Fiore, L; Di Lieto, A; Di Palma, I; Di Virgilio, A; Donath, A; Donovan, F; Dooley, K L; Doravari, S; Dossa, S; Douglas, R; Downes, T P; Drago, M; Drever, R W P; Driggers, J C; Du, Z; Dwyer, S; Eberle, T; Edo, T; Edwards, M; Effler, A; Eggenstein, H; Ehrens, P; Eichholz, J; Eikenberry, S S; Endr?czi, G; Essick, R; Etzel, T; Evans, M; Evans, T; Factourovich, M; Fafone, V; Fairhurst, S; Fang, Q; Farinon, S; Farr, B; Farr, W M; Favata, M; Fehrmann, H; Fejer, M M; Feldbaum, D; Feroz, F; Ferrante, I; Ferrini, F; Fidecaro, F; Finn, L S; Fiori, I; Fisher, R P; Flaminio, R; Fournier, J -D; Franco, S; Frasca, S; Frasconi, F; Frede, M; Frei, Z; Freise, A; Frey, R; Fricke, T T; Fritschel, P; Frolov, V V; Fulda, P; Fyffe, M; Gair, J; Gammaitoni, L; Gaonkar, S; Garufi, F; Gehrels, N; Gemme, G; Genin, E; Gennai, A; Ghosh, S; Giaime, J A; Giardina, K D; Giazotto, A; Gill, C; Gleason, J; Goetz, E; Goetz, R; Gondan, L; González, G; Gordon, N; Gorodetsky, M L; Gossan, S; Goßler, S; Gouaty, R; Gräf, C; Graff, P B; Granata, M; Grant, A; Gras, S; Gray, C; Greenhalgh, R J S; Gretarsson, A M; Groot, P; Grote, H; Grover, K; Grunewald, S; Guidi, G M; Guido, C; Gushwa, K; Gustafson, E K; Gustafson, R; Hammer, D; Hammond, G; Hanke, M; Hanks, J; Hanna, C; Hanson, J; Harms, J; Harry, G M; Harry, I W; Harstad, E D; Hart, M; Hartman, M T; Haster, C -J; Haughian, K; Heidmann, A; Heintze, M; Heitmann, H; Hello, P; Hemming, G; Hendry, M; Heng, I S; Heptonstall, A W; Heurs, M; Hewitson, M; Hild, S; Hoak, D; Hodge, K A; Holt, K; Hooper, S; Hopkins, P; Hosken, D J; Hough, J; Howell, E J; Hu, Y; Hughey, B; Husa, S; Huttner, S H; Huynh, M; Huynh-Dinh, T; Ingram, D R; Inta, R; Isogai, T; Ivanov, A; Iyer, B R; Izumi, K; Jacobson, M; James, E; Jang, H; Jaranowski, P; Ji, Y; Jiménez-Forteza, F; Johnson, W W; Jones, D I; Jones, R; Jonker, R J G; Ju, L; K, Haris; Kalmus, P; Kalogera, V; Kandhasamy, S; Kang, G; Kanner, J B; Karlen, J; Kasprzack, M; Katsavounidis, E; Katzman, W; Kaufer, H; Kawabe, K; Kawazoe, F; Kéfélian, F; Keiser, G M; Keitel, D; Kelley, D B; Kells, W; Khalaidovski, A; Khalili, F Y; Khazanov, E A; Kim, C; Kim, K; Kim, N; Kim, N G; Kim, Y -M; King, E J; King, P J; Kinzel, D L; Kissel, J S; Klimenko, S; Kline, J; Koehlenbeck, S; Kokeyama, K; Kondrashov, V; Koranda, S; Korth, W Z; Kowalska, I
2014-01-01T23:59:59.000Z
The Numerical INJection Analysis (NINJA) project is a collaborative effort between members of the numerical relativity and gravitational-wave astrophysics communities. The purpose of NINJA is to study the ability to detect gravitational waves emitted from merging binary black holes and recover their parameters with next-generation gravitational-wave observatories. We report here on the results of the second NINJA project, NINJA-2, which employs 60 complete binary black hole hybrid waveforms consisting of a numerical portion modelling the late inspiral, merger, and ringdown stitched to a post-Newtonian portion modelling the early inspiral. In a "blind injection challenge" similar to that conducted in recent LIGO and Virgo science runs, we added 7 hybrid waveforms to two months of data recolored to predictions of Advanced LIGO and Advanced Virgo sensitivity curves during their first observing runs. The resulting data was analyzed by gravitational-wave detection algorithms and 6 of the waveforms were recovered w...
Numerical Modeling of Hydro-acoustic Waves In Weakly Compressible Fluid Ali Abdolali1,2
Kirby, James T.
Numerical Modeling of Hydro-acoustic Waves In Weakly Compressible Fluid Ali Abdolali1,2 , James T of Civil Engineering, University of Roma Tre Low-frequency hydro-acoustic waves are precursors of tsunamis. Detection of hydro-acoustic waves generated due to the water column compression triggered by sudden seabed
January 2, 2008 Numerical modeling of the effect of carbon dioxide
Boyer, Edmond
January 2, 2008 Numerical modeling of the effect of carbon dioxide sequestration on the rate souterrain de dioxyde de carbone sur la déformation des calcaires par dissolution sous contrainte: résultats;Abstract When carbon dioxide (CO2) is injected into an aquifer or a depleted geological reservoir, its
Numerical Modelling of Unsaturated Flow in Uniform and Heterogeneous Waste Rock Piles
Aubertin, Michel
Numerical Modelling of Unsaturated Flow in Uniform and Heterogeneous Waste Rock Piles O Fala1 , M Aubertin1,3 , J Molson1 , B Bussière2,3 , G W Wilson4 , R Chapuis1 and V Martin1 ABSTRACT Waste rock piles these piles, many physical, geochemical and biological processes can contribute to the production of AMD
Numerical methods for the simulation of a corrosion model in a nuclear waste deep repository $
Paris-Sud XI, Université de
Numerical methods for the simulation of a corrosion model in a nuclear waste deep repository $ C of the French nuclear waste management agency ANDRA, investigations are conducted to optimize and finalize by the Nuclear Waste Management Agency ANDRA Corresponding author. Phone: +49 30 20372 560, Fax: +49 30 2044975
Numerical analysis of electric field formulations of the eddy current model
RodrÃguez, Rodolfo
Numerical analysis of electric field formulations of the eddy current model Alfredo BermÂ´udez1 methods for the numeri- cal solution of the eddy current problem in a bounded conducting domain crossed): 78M10, 65N30 Key words Low-frequency harmonic Maxwell equations, eddy currents, finite elements
Mathematical and numerical analysis of a transient non-linear axisymmetric eddy current model
RodrÃguez, Rodolfo
Mathematical and numerical analysis of a transient non-linear axisymmetric eddy current model the theoretically predicted behavior of the method, are reported. Keywords transient eddy current Â· axisymmetric is the accurate computation of power losses in the ferromagnetic components of the core due to hysteresis and eddy-current
NUMERICAL SOLUTION OF A TRANSIENT NON-LINEAR AXISYMMETRIC EDDY CURRENT MODEL WITH NON-LOCAL
RodrÃguez, Rodolfo
NUMERICAL SOLUTION OF A TRANSIENT NON-LINEAR AXISYMMETRIC EDDY CURRENT MODEL WITH NON@ing-mat.udec.cl This paper deals with an axisymmetric transient eddy current problem in conductive nonlinear magnetic media of the proposed scheme. Keywords: transient eddy current problem; electromagnetic losses; nonlinear magnetic
A simple numerical model of the apparent loss of eddy current conductivity due to surface roughness
Nagy, Peter B.
A simple numerical model of the apparent loss of eddy current conductivity due to surface roughness of eddy current conductivity has been suggested as a possible means to allow the nondestructive evaluation, the path of the eddy current must follow a more tortuous route in the material, which produces a reduction
Ensemble Kalman Filter Data Assimilation in a 1D Numerical Model Used for Fog Forecasting
Ribes, Aurélien
Ensemble Kalman Filter Data Assimilation in a 1D Numerical Model Used for Fog Forecasting SAMUEL RE significant. This led to the implementation of an ensemble Kalman filter (EnKF) within COBEL-ISBA. The new by using an ensemble Kalman filter (EnKF; Evensen 1994, 2003). Theoreti- cally, ensemble filters
LABORATORY OBSERVATIONS AND NUMERICAL MODELING OF THE EFFECTS OF AN ARRAY OF WAVE ENERGY CONVERTERS
Haller, Merrick
1 LABORATORY OBSERVATIONS AND NUMERICAL MODELING OF THE EFFECTS OF AN ARRAY OF WAVE ENERGY of wave energy converters (WECs) on water waves through the analysis of extensive laboratory experiments absorption is a reasonable predictor of the effect of WECs on the far field. Keywords: wave- energy; spectral
A numerical modeling study on desert oasis self-supporting mechanisms
Chu, Peter C.
A numerical modeling study on desert oasis self-supporting mechanisms Peter C. Chua, *, Shihua Lub February 2005 Abstract Oasis self-supporting mechanisms due to oasis breeze circulation (OBC) are proposed from the oasis makes the oasis surface colder than the surrounding desert surface. The sensible heat
September 25, 2006 Numerical modeling of the effect of carbon dioxide
Paris-Sud XI, Université de
September 25, 2006 Numerical modeling of the effect of carbon dioxide sequestration on the rate souterrain de dioxyde de carbone sur la déformation des calcaires par dissolution sous contrainte: résultats@obs.ujf- grenoble.fr, marielle.collombet@ujf-grenoble.fr, yleguen@lgit.obs.ujf-grenoble.fr. #12;Abstract When carbon
COMPUTATIONAL CHALLENGES IN THE NUMERICAL TREATMENT OF LARGE AIR POLLUTION MODELS
Dimov, Ivan
COMPUTATIONAL CHALLENGES IN THE NUMERICAL TREATMENT OF LARGE AIR POLLUTION MODELS I. DIMOV , K. GEORGIEVy, TZ. OSTROMSKY , R. J. VAN DER PASz, AND Z. ZLATEVx Abstract. The air pollution, and especially the reduction of the air pollution to some acceptable levels, is an important environmental problem, which
Nonlinear inverse problem for a model of ion-exchange filter: numerical recovery of parameters
) and pressure (15 MPa) of hot steam [2]. Some units are made of cheap corrosion and heat-resistant steel which1 Nonlinear inverse problem for a model of ion-exchange filter: numerical recovery of parameters]. Power-generating units of TPP operate under severe corrosive conditions: high temperature (515 - 530°C
NUMERICAL MODELLING OF THERMAL-ELECTRICAL PHENOMENA IN SPARK PLASMA SINTERING
Boyer, Edmond
NUMERICAL MODELLING OF THERMAL-ELECTRICAL PHENOMENA IN SPARK PLASMA SINTERING P. Mondaleka , L'Etudes Structurales), France c Université Paul Sabatier, Toulouse, France Abstract. Spark Plasma Sintering belongs: Finite element method, Spark plasma sintering, powder compaction. INTRODUCTION Spark Plasma Sintering
A numerical ocean circulation model of the Norwegian and Greenland Seas
Stevens, David
A numerical ocean circulation model of the Norwegian and Greenland Seas DAVID P STEVENS School of the Norwegian and Greenland Seas are investigated using a three-dimensional primitive equation ocean circulation and seasonally varying wind and thermohalme forcing. The connections of the Norwegian and Greenland Seas
Numerical Solution of Two Asset Jump Diffusion Models for Option Valuation
Forsyth, Peter A.
Numerical Solution of Two Asset Jump Diffusion Models for Option Valuation Simon S. Clift and Peter parabolic partial integro-differential equation (PIDE). An implicit, finite difference method is derived with an FFT. The method prices both American and European style contracts indepen- dent (under some simple
Boyer, Edmond
A LARGE SCALE CONTINUUM-DISCRETE NUMERICAL MODELLING: APPLICATION TO OVERBURDEN DAMAGE OF A SALT damage on top of an underground solution mining, an in-situ experiment is undertaken above a salt cavity in the Lorraine region (NE of France). The overburden overlying the salt cavity is characterized by a competent
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow
Boyer, Edmond
Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S in a rotor-stator cavity subjected to a superimposed throughflow with heat transfer. Nu- merical predictions field from the heat transfer process. The turbulent flux is approximated by a gradient hypothesis
3 Response to comment by Jozsef Szilagyi on 4 ``Using numerical modelling to evaluate the
McDonnell, Jeffrey J.
REPLY 3 Response to comment by Jozsef Szilagyi on 4 ``Using numerical modelling to evaluate the 5 by Szilagyi is a welcome addition to the de- 15 bate surrounding the link between the hypothesis of 16 a possible explanation for high proportions of 40pre-event water. 41Szilagyi (submitted) has identified
Numerical modelling of avalanches based on Saint-Venant equations using a kinetic scheme
Paris-Sud XI, Université de
avalanches are treated here as a dry granular flow with Coulomb-type behavior. The numerical finite volume of an avalanche over simplified topography. Coulomb-type behavior with constant and variable friction angle modelling, Coulomb friction, Saint-Venant equations, finite volume kinetic scheme. 1 Introduction Granular
Banerjee, Debjyoti
microfluidics Jonathan Siegrist,*a Mary Amasia,a Navdeep Singh,b Debjyoti Banerjeeb and Marc Madoua Received 1st analysis of microchamber filling in centrifugal microfluidics is presented. In the development of micro on centrifugal microfluidic platforms, numerical modeling using the Volume of Fluids method is performed
NUMERICAL MODELLING OF AUTOGENOUS HEALING AND RECOVERY OF MECHANICAL PROPERTIES IN ULTRA-HIGH
Boyer, Edmond
in the cementitious matrix can react with carbon dioxide dissolved in the water filling the crack. Autogenous healingNUMERICAL MODELLING OF AUTOGENOUS HEALING AND RECOVERY OF MECHANICAL PROPERTIES IN ULTRA into the crack and leads to a partial recovery of mechanical properties (Young's modulus, tensile strength
Mathematical, physical and numerical principles essential for models of turbulent mixing
Sharp, David Howland [Los Alamos National Laboratory; Lim, Hyunkyung [STONY BROOK UNIV; Yu, Yan [STONY BROOK UNIV; Glimm, James G [STONY BROOK UNIV
2009-01-01T23:59:59.000Z
We propose mathematical, physical and numerical principles which are important for the modeling of turbulent mixing, especially the classical and well studied Rayleigh-Taylor and Richtmyer-Meshkov instabilities which involve acceleration driven mixing of a fluid discontinuity layer, by a steady accerleration or an impulsive force.
Wells, Scott A.
792 / JOURNAL OF ENVIRONMENTAL ENGINEERING / SEPTEMBER 1999 NUMERICAL MODEL OF SEDIMENTATION with the ASCE Manager of Journals. The manuscript for this paper was submitted for review and possible publication on July 20, 1998. This paper is part of the Journal of Environmental Engineering, Vol. 125, No. 9
The Hamiltonian Particle-Mesh (HPM) method for numerical modeling of atmospheric flows.
Kim, Guebuem
The Hamiltonian Particle-Mesh (HPM) method for numerical modeling of atmospheric flows. Seoleun Shin 15. Feb. 2011 Abstract The Hamiltonian Particle-Mesh (HPM) method is an interesting alternative have developed schemes based on the HPM method for the shallow-water equations on the sphere, nonhydro
NUMERICAL VERIFICATION OF THE RELAP-7 CORE CHANNEL SINGLE-PHASE MODEL
Haihua Zhao; Ling Zou; Hongbin Zhang; Richard Martineau
2014-06-01T23:59:59.000Z
The RELAP-7 code is the next generation of nuclear reactor system safety analysis code being developed at the Idaho National Laboratory (INL). All the physics in RELAP-7 are fully coupled and the errors resulted from the traditional operator-splitting approach are eliminated. By using 2nd order methods in both time and space and eliminating operator-splitting errors, the numerical error of RELAP-7 can be minimized. Numerical verification is the process to verify the orders of numerical methods. It is an important part of modern verification and validation process. The core channel component in RELAP-7 is designed to simulate coolant flow as well as the conjugated heat transfer between coolant flow and the fuel rod. A special treatment at fuel centerline to avoid numerical singularity for the cylindrical heat conduction in the continuous finite element mesh is discussed. One steady state test case and one fast power up transient test case are utilized for the verification of the core channel model with single-phase flow. Analytical solution for the fuel pin temperature and figures of merit such as peak clad temperature and peak fuel temperature are used to define numerical errors. These cases prove that the mass and energy are well conserved and 2nd order convergence rates for both time and space are achieved in the core channel model.
Modeling Resources for Activity Coordination and Scheduling
Massachusetts at Amherst, University of
Modeling Resources for Activity Coordination and Scheduling Rodion M. Podorozhny , Barbara Staudt describes experience in applying a resource man- agement system to problems in two areas of agent and activity coordi- nation. In the paper we argue that precise speci cation of resources is important
Modeling Resources for Activity Coordination and Scheduling
Massachusetts at Amherst, University of
Modeling Resources for Activity Coordination and Scheduling Rodion M. Podorozhny , Barbara Staudt describes experience in applying a resource man agement system to problems in two areas of agent and activity coordi nation. In the paper we argue that precise specification of resources is important
Coclite, A; De Palma, P; Pascazio, G
2015-01-01T23:59:59.000Z
The present paper deals with the numerical study of high pressure LOx/H2 or LOx/hydrocarbon combustion for propulsion systems. The present research effort is driven by the continued interest in achieving low cost, reliable access to space and more recently, by the renewed interest in hypersonic transportation systems capable of reducing time-to-destination. Moreover, combustion at high pressure has been assumed as a key issue to achieve better propulsive performance and lower environmental impact, as long as the replacement of hydrogen with a hydrocarbon, to reduce the costs related to ground operations and increase flexibility. The current work provides a model for the numerical simulation of high- pressure turbulent combustion employing detailed chemistry description, embedded in a RANS equations solver with a Low Reynolds number k-omega turbulence model. The model used to study such a combustion phenomenon is an extension of the standard flamelet-progress-variable (FPV) turbulent combustion model combined ...
Direct Numerical Simulations of the Kraichnan Model: Scaling Exponents and Fusion Rules
Adrienne L. Fairhall; Barak Galanti; Victor S. L'vov; Itamar Procaccia
1997-07-01T23:59:59.000Z
We present results from direct numerical simulations of the Kraichnan model for passive scalar advection by a rapidly-varying random scaling velocity field for intermediate values of the velocity scaling exponent. These results are compared with the scaling exponents predicted for this model by Kraichnan. Further, we test the recently proposed fusion rules which govern the scaling properties of multi-point correlations, and present results on the linearity of the conditional statistics of the Laplacian operator on the scalar field.
Development and validation of a vertically two-dimensional mesoscale numerical model
Walters, Michael Kent
1985-01-01T23:59:59.000Z
values of model variables for static test and kinetic energy calculations . . . . . . . . . 25 2 Results of kinetic energy budget calculations . . 29 ? 1 -5 Surface heating rate (K s x 10 ) . . . . . . . 32 4 Initial values of variables for nonlinear.... These tests provide an important means of debugging the numerical scheme. The validation tests performed on the mesoscale model consisted of a simple static test, calculation of the mass continuity and the kinet. ic energy budget, and performing non...
Modelling and Numerical Simulation of Gas Migration in a Nuclear Waste Repository
Bourgeat, Alain; Smai, Farid
2010-01-01T23:59:59.000Z
We present a compositional compressible two-phase, liquid and gas, flow model for numerical simulations of hydrogen migration in deep geological radioactive waste repository. This model includes capillary effects and the gas diffusivity. The choice of the main variables in this model, Total or Dissolved Hydrogen Mass Concentration and Liquid Pressure, leads to a unique and consistent formulation of the gas phase appearance and disappearance. After introducing this model, we show computational evidences of its adequacy to simulate gas phase appearance and disappearance in different situations typical of underground radioactive waste repository.
Qualification of the ITER CS Quench Detection System using Numerical Modeling
Martovetsky, Nicolai N [ORNL; Radovinsky, Alexey L [ORNL
2013-01-01T23:59:59.000Z
Abstract The ITER Central Solenoid (CS) magnet needs to be protected against overheating of the conductor in the event of the occurrence of a normal zone (NZ). Due to a large amount of stored energy and slow NZ propagation, the NZ needs to be detected and the switchyard needs to open the breakers within 2 s after detection of the NZ. The CS will be discharged on a dump resistor with a time constant of 7.5 s. During operation of the CS and its interaction with the poloidal field (PF) coils and plasma current, the CS experiences large inductive voltages from multiple sources, including nonlinear signals from eddy currents in the vacuum vessel and plasma current variation, that make the task of detecting the resistive signal even more difficult. This inductive voltage needs to be cancelled by quench detection (QD) hardware (e.g., bridges, converters, filters, processors) and appropriate processing of the QD signals to reliably detect NZ initiation and propagation. Two redundant schemes are proposed as the baseline for the CS QD System: 1) A scheme with Regular Voltage Taps (RVT) from triads of Double Pancakes (DP) supplemented by Central Difference Averaging (CDA) and by digital suppression of the inductive voltage from all active coils (the CS and PF coils). Voltage taps are taken from helium outlets at the CS outer diameter. 2)A scheme with Cowound Voltage Taps (CVT) taken from cowound wires routed from the helium inlet at the CS inner diameter. Summary of results of the numerical modeling of the performance of both baseline CS QD systems is presented in this paper. Index Terms Quench detection, Central Solenoid, ITER
Numerical upscaling for the eddy-current model with stochastic magnetic materials
Eberhard, Jens P. [Computer Simulation Technology, Bad Nauheimer Strasse, 19, D-64289 Darmstadt (Germany)], E-mail: jens.eberhard@cst.com; Popovic, Dan [Simulation in Technology, University of Heidelberg, Im Neuenheimer Feld 368, D-69120 Heidelberg (Germany)], E-mail: dan.popovic@stud.uni-heidelberg.de; Wittum, Gabriel [Simulation in Technology, University of Heidelberg, Im Neuenheimer Feld 368, D-69120 Heidelberg (Germany)], E-mail: wittum@uni-hd.de
2008-04-01T23:59:59.000Z
This paper deals with the upscaling of the time-harmonic Maxwell equations for heterogeneous media. We analyze the eddy-current approximation of Maxwell's equations to describe the electric field for heterogeneous, isotropic magnetic materials. The magnetic permeability of the materials is assumed to have random heterogeneities described by a Gaussian random field. We apply the so-called Coarse Graining method to develop a numerical upscaling of the eddy-current model. The upscaling uses filtering and averaging procedures in Fourier space which results in a formulation of the eddy-current model on coarser resolution scales where the influence of sub-scale fluctuations is modeled by effective scale- and space-dependent reluctivity tensors. The effective reluctivity tensors can be obtained by solving local partial differential equations which contain a Laplacian as well as a curl-curl operator. We present a computational method how the equation of the combined operators can be discretized and solved numerically using an extended variational formulation compared to standard discretizations. We compare the results of the numerical upscaling of the eddy-current model with theoretical results of Eberhard [J.P. Eberhard, Upscaling for the time-harmonic Maxwell equations with heterogeneous magnetic materials, Physical Review E 72 (3), (2005)] and obtain a very good agreement.
Numerical Modeling of Non-adiabatic Heat-Recirculating Combustors C. H. Kuo and P. D. Ronney
1 Numerical Modeling of Non-adiabatic Heat-Recirculating Combustors C. H. Kuo and P. D. Ronney@usc.edu Colloquium topic area: 12. New Technology Concepts Keywords: Micro-combustion, Heat-recirculating combustors, Extinction limits Shortened running title: Numerical Modeling of Heat-Recirculating Combustors Word count
Zhi, Yuanzhe
2013-07-11T23:59:59.000Z
model experimental results of solid dock are also compared with the numerical simulation. These comparisons indicate that the motion characteristics of the model container ship represent similar trends for both rotations and translations...
Jonathan Blackman; Scott E. Field; Chad R. Galley; Bela Szilagyi; Mark A. Scheel; Manuel Tiglio; Daniel A. Hemberger
2015-02-26T23:59:59.000Z
Simulating a binary black hole coalescence by solving Einstein's equations is computationally expensive, requiring days to months of supercomputing time. In this paper, we construct an accurate and fast-to-evaluate surrogate model for numerical relativity (NR) waveforms from non-spinning binary black hole coalescences with mass ratios from $1$ to $10$ and durations corresponding to about $15$ orbits before merger. Our surrogate, which is built using reduced order modeling techniques, is distinct from traditional modeling efforts. We find that the full multi-mode surrogate model agrees with waveforms generated by NR to within the numerical error of the NR code. In particular, we show that our modeling strategy produces surrogates which can correctly predict NR waveforms that were {\\em not} used for the surrogate's training. For all practical purposes, then, the surrogate waveform model is equivalent to the high-accuracy, large-scale simulation waveform but can be evaluated in a millisecond to a second depending on the number of output modes and the sampling rate. Our model includes all spherical-harmonic ${}_{-2}Y_{\\ell m}$ waveform modes that can be resolved by the NR code up to $\\ell=8$, including modes that are typically difficult to model with other approaches. We assess the model's uncertainty, which could be useful in parameter estimation studies seeking to incorporate model error. We anticipate NR surrogate models to be useful for rapid NR waveform generation in multiple-query applications like parameter estimation, template bank construction, and testing the fidelity of other waveform models.
Numerical-Model Investigation of the Hydrothermal Regime of a Straight-Through Shallow Cooling Pond
Sokolov, A. S. [JSC 'VNIIG im. B. E. Vedeneeva' (Russian Federation)] [JSC 'VNIIG im. B. E. Vedeneeva' (Russian Federation)
2013-11-15T23:59:59.000Z
A mathematic model based on solution of hydrodynamics and heat-transfer equations by the finite-element method is constructed to predict the hydrothermal regime of a straight-through shallow cooling pond, which provides cooling circulating water to a repository of spent nuclear fuel. Numerical experiments made it possible to evaluate the influence exerted by wind conditions and flow rate of water in the river on the temperature of the circulating water.
An investigation of analytical and numerical sucker rod pumping mathematical models
Schafer, Donald Joseph
1987-01-01T23:59:59.000Z
of MASTER OF SCIENCE May 1987 Major Subject: Petroleum Engineering AN INVESTIGATION OF ANALYTICAL AND NUMERICAL SUCKER ROD PUMPING MATHEMATICAL MODELS A Thesis by DONALD JOSEPH SCHAFER Approved as to style and content by: 7d JW. J ni (Chai... to Sucker Rod Pumping Research, Inc. , developed a method for computing downhole forces and displacements using an analog computer simulation. The procedure that results from this work, commonly called the API method, considers the total sucker rod...
Numerical modeling of hydraulic fracture problem in permeable medium using cohesive zone model
Paris-Sud XI, Université de
or radioactive waste [30], geothermal Corresponding author Email address: benoit.carrier@enpc.fr (Benoit Carrier processes. During the last sixty years, numerous papers [3, 7, 14, 21, 35, 34, 41, 25, 27, 22, 38, 36, 1. In the recent years, a scaling and asymptotic framework was built to determine the influence of the physical
Thermo--inertial bouncing of a relativistic collapsing sphere: A numerical model
L. Herrera; A. Di Prisco; W. Barreto
2005-12-05T23:59:59.000Z
We present a numerical model of a collapsing radiating sphere, whose boundary surface undergoes bouncing due to a decreasing of its inertial mass density (and, as expected from the equivalence principle, also of the ``gravitational'' force term) produced by the ``inertial'' term of the transport equation. This model exhibits for the first time the consequences of such an effect, and shows that under physically reasonable conditions this decreasing of the gravitational term in the dynamic equation may be large enough as to revert the collapse and produce a bouncing of the boundary surface of the sphere.
Moist processes and the quasi-hydrostatic approximation in a mesoscale numerical model
Kennedy, Charles Joseph
1987-01-01T23:59:59.000Z
of Committee) James P. McGuirk (Member) J'ohn M. Klinck (Member) James R. Sco ns (Head of Department) December 1987 ABSTRACT Moist Processes and the Ouasi-Hydrostatic Approximation in a Mesoscale Numerical Model. (December 1987) Charles Joseph...HV)ds' ? gHp s + gHps a dg 1 gt = (gt), s 1 1 (19) the pressure tendency at the model top equation: g f V ~ (pHV)ds' ? VS Vp Q ( el 1 + 0 Yp CpT ? V (H0) ds' )' ? ) (20) Richardson's equation for vertical motion: s f , , f Id d'D &DDVdd ' ? 0 D, 0...
Bammann, Douglas J.; Johnson, G. C. (University of California, Berkeley, CA); Marin, Esteban B.; Regueiro, Richard A. (University of Colorado, Boulder, CO)
2006-01-01T23:59:59.000Z
In this report we present the formulation of the physically-based Evolving Microstructural Model of Inelasticity (EMMI) . The specific version of the model treated here describes the plasticity and isotropic damage of metals as being currently applied to model the ductile failure process in structural components of the W80 program . The formulation of the EMMI constitutive equations is framed in the context of the large deformation kinematics of solids and the thermodynamics of internal state variables . This formulation is focused first on developing the plasticity equations in both the relaxed (unloaded) and current configurations. The equations in the current configuration, expressed in non-dimensional form, are used to devise the identification procedure for the plasticity parameters. The model is then extended to include a porosity-based isotropic damage state variable to describe the progressive deterioration of the strength and mechanical properties of metals induced by deformation . The numerical treatment of these coupled plasticity-damage constitutive equations is explained in detail. A number of examples are solved to validate the numerical implementation of the model.
Probe measurements and numerical model predictions of evolving size distributions in premixed flames
De Filippo, A.; Sgro, L.A.; Lanzuolo, G.; D'Alessio, A. [Dipartimento di Ingegneria Chimica, Universita degli Studi di Napoli Federico II, Piazzale Tecchio 80, 80125 Napoli (Italy)
2009-09-15T23:59:59.000Z
Particle size distributions (PSDs), measured with a dilution probe and a Differential Mobility Analyzer (DMA), and numerical predictions of these PSDs, based on a model that includes only coagulation or alternatively inception and coagulation, are compared to investigate particle growth processes and possible sampling artifacts in the post-flame region of a C/O = 0.65 premixed laminar ethylene-air flame. Inputs to the numerical model are the PSD measured early in the flame (the initial condition for the aerosol population) and the temperature profile measured along the flame's axial centerline. The measured PSDs are initially unimodal, with a modal mobility diameter of 2.2 nm, and become bimodal later in the post-flame region. The smaller mode is best predicted with a size-dependent coagulation model, which allows some fraction of the smallest particles to escape collisions without resulting in coalescence or coagulation through the size-dependent coagulation efficiency ({gamma}{sub SD}). Instead, when {gamma} = 1 and the coagulation rate is equal to the collision rate for all particles regardless of their size, the coagulation model significantly under predicts the number concentration of both modes and over predicts the size of the largest particles in the distribution compared to the measured size distributions at various heights above the burner. The coagulation ({gamma}{sub SD}) model alone is unable to reproduce well the larger particle mode (mode II). Combining persistent nucleation with size-dependent coagulation brings the predicted PSDs to within experimental error of the measurements, which seems to suggest that surface growth processes are relatively insignificant in these flames. Shifting measured PSDs a few mm closer to the burner surface, generally adopted to correct for probe perturbations, does not produce a better matching between the experimental and the numerical results. (author)
W. Schmidt; J. C. Niemeyer; W. Hillebrandt
2006-01-23T23:59:59.000Z
We present a one-equation subgrid scale model that evolves the turbulence energy corresponding to unresolved velocity fluctuations in large eddy simulations. The model is derived in the context of the Germano consistent decomposition of the hydrodynamical equations. The eddy-viscosity closure for the rate of energy transfer from resolved toward subgrid scales is localised by means of a dynamical procedure for the computation of the closure parameter. Therefore, the subgrid scale model applies to arbitrary flow geometry and evolution. For the treatment of microscopic viscous dissipation a semi-statistical approach is used, and the gradient-diffusion hypothesis is adopted for turbulent transport. A priori tests of the localised eddy-viscosity closure and the gradient-diffusion closure are made by analysing data from direct numerical simulations. As an a posteriori testing case, the large eddy simulation of thermonuclear combustion in forced isotropic turbulence is discussed. We intend the formulation of the subgrid scale model in this paper as a basis for more advanced applications in numerical simulations of complex astrophysical phenomena involving turbulence.
Active Brownian Motion Models and Applications to Ratchets
Alessandro Fiasconaro; Werner Ebeling; Ewa Gudowska-Nowak
2008-06-29T23:59:59.000Z
We give an overview over recent studies on the model of Active Brownian Motion (ABM) coupled to reservoirs providing free energy which may be converted into kinetic energy of motion. First, we present an introduction to a general concept of active Brownian particles which are capable to take up energy from the source and transform part of it in order to perform various activities. In the second part of our presentation we consider applications of ABM to ratchet systems with different forms of differentiable potentials. Both analytical and numerical evaluations are discussed for three cases of sinusoidal, staircase-like and Mateos ratchet potentials, also with the additional loads modeled by tilted potential structure. In addition, stochastic character of the kinetics is investigated by considering perturbation by Gaussian white noise which is shown to be responsible for driving the directionality of the asymptotic flux in the ratchet. This \\textit{stochastically driven directionality} effect is visualized as a strong nonmonotonic dependence of the statistics of the right versus left trajectories of motion leading to a net current of particles. Possible applications of the ratchet systems to molecular motors are also briefly discussed
Seebold, J.G. [Chevron Research and Technology Co., Richmond, CA (United States); Kee, R.J.; Lutz, A.J. [Sandia National Labs., Albuquerque, NM (United States); Pitz, W.J.; Westbrook, C.K. [Lawrence Livermore National Lab., CA (United States); Senkan, S. [California Univ., Los Angeles, CA (United States)
1992-09-01T23:59:59.000Z
A collaborative research program initiated to study the emissions of a wide variety of chemical species from stationary combustion systems. These product species have been included in the Clean Air act legislation and their emissions must be rigidly controlled, but there is a need for much better understanding of the physical and chemical mechanisms that produce and consume them. We are using numerical modeling study the chemical reactions and fluid mechanical factors that occur in industrial processes: we are examining systems including premixed and diffusion flames, stirred reactors and plug flow reactors in these modeling studies to establish the major factors leading to emissions of these chemicals. In addition, we are applying advanced laser diagnostic techniques to validate the model predictions and to study the possibilities of developing sophisticated sensors to detect emissions of undesirable species in real time. This paper will discuss the organization of this collaborative effort and its results to date.
Schmidt, W; Niemeyer, J C
2006-01-01T23:59:59.000Z
We present a one-equation subgrid scale model that evolves the turbulence energy corresponding to unresolved velocity fluctuations in large eddy simulations. The model is derived in the context of the Germano consistent decomposition of the hydrodynamical equations. The eddy-viscosity closure for the rate of energy transfer from resolved toward subgrid scales is localised by means of a dynamical procedure for the computation of the closure parameter. Therefore, the subgrid scale model applies to arbitrary flow geometry and evolution. For the treatment of microscopic viscous dissipation a semi-statistical approach is used, and the gradient-diffusion hypothesis is adopted for turbulent transport. A priori tests of the localised eddy-viscosity closure and the gradient-diffusion closure are made by analysing data from direct numerical simulations. As an a posteriori testing case, the large eddy simulation of thermonuclear combustion in forced isotropic turbulence is discussed. We intend the formulation of the sub...
The LIGO Scientific Collaboration; the Virgo Collaboration; the NINJA-2 Collaboration; :; J. Aasi; B. P. Abbott; R. Abbott; T. Abbott; M. R. Abernathy; T. Accadia; F. Acernese; K. Ackley; C. Adams; T. Adams; P. Addesso; R. X. Adhikari; C. Affeldt; M. Agathos; N. Aggarwal; O. D. Aguiar; A. Ain; P. Ajith; A. Alemic; B. Allen; A. Allocca; D. Amariutei; M. Andersen; R. Anderson; S. B. Anderson; W. G. Anderson; K. Arai; M. C. Araya; C. Arceneaux; J. Areeda; S. M. Aston; P. Astone; P. Aufmuth; C. Aulbert; L. Austin; B. E. Aylott; S. Babak; P. T. Baker; G. Ballardin; S. W. Ballmer; J. C. Barayoga; M. Barbet; B. C. Barish; D. Barker; F. Barone; B. Barr; L. Barsotti; M. Barsuglia; M. A. Barton; I. Bartos; R. Bassiri; A. Basti; J. C. Batch; J. Bauchrowitz; Th. S. Bauer; B. Behnke; M. Bejger; M. G. Beker; C. Belczynski; A. S. Bell; C. Bell; G. Bergmann; D. Bersanetti; A. Bertolini; J. Betzwieser; P. T. Beyersdorf; I. A. Bilenko; G. Billingsley; J. Birch; S. Biscans; M. Bitossi; M. A. Bizouard; E. Black; J. K. Blackburn; L. Blackburn; D. Blair; S. Bloemen; M. Blom; O. Bock; T. P. Bodiya; M. Boer; G. Bogaert; C. Bogan; C. Bond; F. Bondu; L. Bonelli; R. Bonnand; R. Bork; M. Born; V. Boschi; Sukanta Bose; L. Bosi; C. Bradaschia; P. R. Brady; V. B. Braginsky; M. Branchesi; J. E. Brau; T. Briant; D. O. Bridges; A. Brillet; M. Brinkmann; V. Brisson; A. F. Brooks; D. A. Brown; D. D. Brown; F. Brückner; S. Buchman; T. Bulik; H. J. Bulten; A. Buonanno; R. Burman; D. Buskulic; C. Buy; L. Cadonati; G. Cagnoli; J. Calderón Bustillo; E. Calloni; J. B. Camp; P. Campsie; K. C. Cannon; B. Canuel; J. Cao; C. D. Capano; F. Carbognani; L. Carbone; S. Caride; A. Castiglia; S. Caudill; M. Cavaglià; F. Cavalier; R. Cavalieri; C. Celerier; G. Cella; C. Cepeda; E. Cesarini; R. Chakraborty; T. Chalermsongsak; S. J. Chamberlin; S. Chao; P. Charlton; E. Chassande-Mottin; X. Chen; Y. Chen; A. Chincarini; A. Chiummo; H. S. Cho; J. Chow; N. Christensen; Q. Chu; S. S. Y. Chua; S. Chung; G. Ciani; F. Clara; J. A. Clark; F. Cleva; E. Coccia; P. -F. Cohadon; A. Colla; C. Collette; M. Colombini; L. Cominsky; M. Constancio Jr.; A. Conte; D. Cook; T. R. Corbitt; M. Cordier; N. Cornish; A. Corpuz; A. Corsi; C. A. Costa; M. W. Coughlin; S. Coughlin; J. -P. Coulon; S. Countryman; P. Couvares; D. M. Coward; M. Cowart; D. C. Coyne; R. Coyne; K. Craig; J. D. E. Creighton; S. G. Crowder; A. Cumming; L. Cunningham; E. Cuoco; K. Dahl; T. Dal Canton; M. Damjanic; S. L. Danilishin; S. D'Antonio; K. Danzmann; V. Dattilo; H. Daveloza; M. Davier; G. S. Davies; E. J. Daw; R. Day; T. Dayanga; G. Debreczeni; J. Degallaix; S. Deléglise; W. Del Pozzo; T. Denker; T. Dent; H. Dereli; V. Dergachev; R. De Rosa; R. T. DeRosa; R. DeSalvo; S. Dhurandhar; M. Díaz; L. Di Fiore; A. Di Lieto; I. Di Palma; A. Di Virgilio; A. Donath; F. Donovan; K. L. Dooley; S. Doravari; S. Dossa; R. Douglas; T. P. Downes; M. Drago; R. W. P. Drever; J. C. Driggers; Z. Du; S. Dwyer; T. Eberle; T. Edo; M. Edwards; A. Effler; H. Eggenstein; P. Ehrens; J. Eichholz; S. S. Eikenberry; G. Endr?czi; R. Essick; T. Etzel; M. Evans; T. Evans; M. Factourovich; V. Fafone; S. Fairhurst; Q. Fang; S. Farinon; B. Farr; W. M. Farr; M. Favata; H. Fehrmann; M. M. Fejer; D. Feldbaum; F. Feroz; I. Ferrante; F. Ferrini; F. Fidecaro; L. S. Finn; I. Fiori; R. P. Fisher; R. Flaminio; J. -D. Fournier; S. Franco; S. Frasca; F. Frasconi; M. Frede; Z. Frei; A. Freise; R. Frey; T. T. Fricke; P. Fritschel; V. V. Frolov; P. Fulda; M. Fyffe; J. Gair; L. Gammaitoni; S. Gaonkar; F. Garufi; N. Gehrels; G. Gemme; E. Genin; A. Gennai; S. Ghosh; J. A. Giaime; K. D. Giardina; A. Giazotto; C. Gill; J. Gleason; E. Goetz; R. Goetz; L. Gondan; G. González; N. Gordon; M. L. Gorodetsky; S. Gossan; S. Goßler; R. Gouaty; C. Gräf; P. B. Graff; M. Granata; A. Grant; S. Gras; C. Gray; R. J. S. Greenhalgh; A. M. Gretarsson; P. Groot; H. Grote; K. Grover; S. Grunewald; G. M. Guidi; C. Guido; K. Gushwa; E. K. Gustafson; R. Gustafson; D. Hammer; G. Hammond; M. Hanke; J. Hanks; C. Hanna; J. Hanson; J. Harms; G. M. Harry; I. W. Harry; E. D. Harstad; M. Hart; M. T. Hartman; C. -J. Haster; K. Haughian; A. Heidmann; M. Heintze; H. Heitmann; P. Hello; G. Hemming; M. Hendry; I. S. Heng; A. W. Heptonstall; M. Heurs; M. Hewitson; S. Hild; D. Hoak; K. A. Hodge; K. Holt; S. Hooper; P. Hopkins; D. J. Hosken; J. Hough; E. J. Howell; Y. Hu; B. Hughey; S. Husa; S. H. Huttner; M. Huynh; T. Huynh-Dinh; D. R. Ingram; R. Inta; T. Isogai; A. Ivanov; B. R. Iyer; K. Izumi; M. Jacobson; E. James; H. Jang; P. Jaranowski; Y. Ji; F. Jiménez-Forteza; W. W. Johnson; D. I. Jones; R. Jones; R. J. G. Jonker; L. Ju; Haris K; P. Kalmus; V. Kalogera; S. Kandhasamy; G. Kang; J. B. Kanner; J. Karlen; M. Kasprzack; E. Katsavounidis; W. Katzman; H. Kaufer; K. Kawabe; F. Kawazoe; F. Kéfélian; G. M. Keiser; D. Keitel; D. B. Kelley; W. Kells; A. Khalaidovski
2014-01-05T23:59:59.000Z
The Numerical INJection Analysis (NINJA) project is a collaborative effort between members of the numerical relativity and gravitational-wave astrophysics communities. The purpose of NINJA is to study the ability to detect gravitational waves emitted from merging binary black holes and recover their parameters with next-generation gravitational-wave observatories. We report here on the results of the second NINJA project, NINJA-2, which employs 60 complete binary black hole hybrid waveforms consisting of a numerical portion modelling the late inspiral, merger, and ringdown stitched to a post-Newtonian portion modelling the early inspiral. In a "blind injection challenge" similar to that conducted in recent LIGO and Virgo science runs, we added 7 hybrid waveforms to two months of data recolored to predictions of Advanced LIGO and Advanced Virgo sensitivity curves during their first observing runs. The resulting data was analyzed by gravitational-wave detection algorithms and 6 of the waveforms were recovered with false alarm rates smaller than 1 in a thousand years. Parameter estimation algorithms were run on each of these waveforms to explore the ability to constrain the masses, component angular momenta and sky position of these waveforms. We also perform a large-scale monte-carlo study to assess the ability to recover each of the 60 hybrid waveforms with early Advanced LIGO and Advanced Virgo sensitivity curves. Our results predict that early Advanced LIGO and Advanced Virgo will have a volume-weighted average sensitive distance of 300Mpc (1Gpc) for $10M_{\\odot}+10M_{\\odot}$ ($50M_{\\odot}+50M_{\\odot}$) binary black hole coalescences. We demonstrate that neglecting the component angular momenta in the waveform models used in matched-filtering will result in a reduction in sensitivity for systems with large component angular momenta. [Abstract abridged for ArXiv, full version in PDF
Monitoring and Numerical Modeling of Shallow CO{sub 2} Injection, Greene County, Missouri
Rovey, Charles; Gouzie, Douglas; Biagioni, Richard
2013-09-30T23:59:59.000Z
The project titled Monitoring and Numerical Modeling of Shallow CO{sub 2} Injection, Greene County, Missouri provided training for three graduate students in areas related to carbon capture and storage. Numerical modeling of CO{sub 2} injection into the St. Francois aquifer at the Southwest Power Plant Site in Greene County, Missouri indicates that up to 4.1 x 10{sup 5} metric tons of CO{sub 2} per year could be injected for 30 years without exceeding a 3 MPa differential injection pressure. The injected CO{sub 2} would remain sequestered below the top of the overlying caprock (St. Francois confining unit) for more than 1000 years. Geochemical modeling indicates that portions of the injected CO{sub 2} will react rapidly with trace minerals in the aquifer to form various solid carbonate mineral phases. These minerals would store significant portions of injected CO{sub 2} over geologic time scales. Finally, a GIS data base on the pore-fluid chemistry of the overlying aquifer system in Missouri, the Ozark aquifer, was compiled from many sources. This data base could become useful in monitoring for leakage from future CO{sub 2} sequestration sites.
A phase screen model for simulating numerically the propagation of a laser beam in rain
Lukin, I P; Rychkov, D S; Falits, A V [Institute of Atmospheric Optics, Siberian Branch, Russian Academy of Sciences, Tomsk (Russian Federation); Lai, Kin S; Liu, Min R [DSO National Laboratories 20 (Singapore)
2009-09-30T23:59:59.000Z
The method based on the generalisation of the phase screen method for a continuous random medium is proposed for simulating numerically the propagation of laser radiation in a turbulent atmosphere with precipitation. In the phase screen model for a discrete component of a heterogeneous 'air-rain droplet' medium, the amplitude screen describing the scattering of an optical field by discrete particles of the medium is replaced by an equivalent phase screen with a spectrum of the correlation function of the effective dielectric constant fluctuations that is similar to the spectrum of a discrete scattering component - water droplets in air. The 'turbulent' phase screen is constructed on the basis of the Kolmogorov model, while the 'rain' screen model utiises the exponential distribution of the number of rain drops with respect to their radii as a function of the rain intensity. Theresults of the numerical simulation are compared with the known theoretical estimates for a large-scale discrete scattering medium. (propagation of laser radiation in matter)
Numerical modeling of mixed sediment resuspension, transport, and deposition during the March 1998 sediment resuspension of mixed (cohesive plus noncohesive) sediment is developed and applied to quantitatively simulate the March 1998 resuspension events in southern Lake Michigan. Some characteristics
Pan, Dongqing; Chien Jen, Tien [Department of Mechanical Engineering, University of Wisconsin-Milwaukee, Milwaukee, Wisconsin 53201 (United States); Li, Tao [School of Mechanical Engineering, Dalian University of Technology, Dalian 116024 (China); Yuan, Chris, E-mail: cyuan@uwm.edu [Department of Mechanical Engineering, University of Wisconsin-Milwaukee, 3200 North Cramer Street, Milwaukee, Wisconsin 53211 (United States)
2014-01-15T23:59:59.000Z
This paper characterizes the carrier gas flow in the atomic layer deposition (ALD) vacuum reactor by introducing Lattice Boltzmann Method (LBM) to the ALD simulation through a comparative study of two LBM models. Numerical models of gas flow are constructed and implemented in two-dimensional geometry based on lattice Bhatnagar–Gross–Krook (LBGK)-D2Q9 model and two-relaxation-time (TRT) model. Both incompressible and compressible scenarios are simulated and the two models are compared in the aspects of flow features, stability, and efficiency. Our simulation outcome reveals that, for our specific ALD vacuum reactor, TRT model generates better steady laminar flow features all over the domain with better stability and reliability than LBGK-D2Q9 model especially when considering the compressible effects of the gas flow. The LBM-TRT is verified indirectly by comparing the numerical result with conventional continuum-based computational fluid dynamics solvers, and it shows very good agreement with these conventional methods. The velocity field of carrier gas flow through ALD vacuum reactor was characterized by LBM-TRT model finally. The flow in ALD is in a laminar steady state with velocity concentrated at the corners and around the wafer. The effects of flow fields on precursor distributions, surface absorptions, and surface reactions are discussed in detail. Steady and evenly distributed velocity field contribute to higher precursor concentration near the wafer and relatively lower particle velocities help to achieve better surface adsorption and deposition. The ALD reactor geometry needs to be considered carefully if a steady and laminar flow field around the wafer and better surface deposition are desired.
Numeric-modeling sensitivity analysis of the performance of wind turbine arrays
Lissaman, P.B.S.; Gyatt, G.W.; Zalay, A.D.
1982-06-01T23:59:59.000Z
An evaluation of the numerical model created by Lissaman for predicting the performance of wind turbine arrays has been made. Model predictions of the wake parameters have been compared with both full-scale and wind tunnel measurements. Only limited, full-scale data were available, while wind tunnel studies showed difficulties in representing real meteorological conditions. Nevertheless, several modifications and additions have been made to the model using both theoretical and empirical techniques and the new model shows good correlation with experiment. The larger wake growth rate and shorter near wake length predicted by the new model lead to reduced interference effects on downstream turbines and hence greater array efficiencies. The array model has also been re-examined and now incorporates the ability to show the effects of real meteorological conditions such as variations in wind speed and unsteady winds. The resulting computer code has been run to show the sensitivity of array performance to meteorological, machine, and array parameters. Ambient turbulence and windwise spacing are shown to dominate, while hub height ratio is seen to be relatively unimportant. Finally, a detailed analysis of the Goodnoe Hills wind farm in Washington has been made to show how power output can be expected to vary with ambient turbulence, wind speed, and wind direction.
Temperature Modeling in Activated Sludge Systems: A Case Study
Wells, Scott A.
Temperature Modeling in Activated Sludge Systems: A Case Study Jacek Makinia, Scott A. Wells, Piotr Zima ABSTRACT: A model of temperature dynamics was developed as part of a general model of activated-sludge biochemical-energy inputs and other activated-sludge, heat-balance terms. All the models were tested under
Full-Scale Numerical Modeling of Turbulent Processes in the Earth's Ionosphere
Eliasson, B. [Department of Physics, Umeaa University, SE-901 87 Umeaa (Sweden); Stenflo, L. [Department of Physics, Umeaa University, SE-901 87 Umeaa (Sweden); Department of Physics, Linkoeping University, SE-581 83 Linkoeping (Sweden); Shukla, P. K. [Institut fuer Theoretische Physik IV, Fakultaet fuer Physik und Astronomie, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)
2008-10-15T23:59:59.000Z
We present a full-scale simulation study of ionospheric turbulence by means of a generalized Zakharov model based on the separation of variables into high-frequency and slow time scales. The model includes realistic length scales of the ionospheric profile and of the electromagnetic and electrostatic fields, and uses ionospheric plasma parameters relevant for high-latitude radio facilities such as Eiscat and HAARP. A nested grid numerical method has been developed to resolve the different length-scales, while avoiding severe restrictions on the time step. The simulation demonstrates the parametric decay of the ordinary mode into Langmuir and ion-acoustic waves, followed by a Langmuir wave collapse and short-scale caviton formation, as observed in ionospheric heating experiments.
Numerical modeling of roll structures in mesoscale vortexes over the Black Sea
Iarova, D A
2014-01-01T23:59:59.000Z
This paper is a case study of horizontal atmospheric rolls that formed over the Black Sea on 16 August 2007. The rolls were discovered in WRF modeling results for a mesoscale cyclone that originated over the sea on 15 August 2007. The roll formation mechanisms, such as Rayleigh-Benard convective instability, dynamic instability, advection and stretching of vertical velocity field inhomogeneities, are considered. It is shown that indeed convective instability played an important role in the roll formation but dynamic instability did not occur. In order to distinguish other possible mechanisms of the roll formation numerical experiments were performed. In these experiments sea surface temperature in the initial conditions was decreased in order to prevent convective instability. Even though convective instability was suppressed roll-like structures still appeared in the modeling results, although their height and circulation velocity were smaller than in the control run. It was found that these structures were ...
Temperature distributions in the laser-heated diamond anvil cell from 3-D numerical modeling
Rainey, E. S. G.; Kavner, A. [Department of Earth and Space Sciences, University of California, Los Angeles, California 90095 (United States); Hernlund, J. W. [Department of Earth and Planetary Science, University of California, Berkeley, California 94720 (United States); Earth-Life Science Institute, Megoro, Tokyo 152-8551 (Japan)
2013-11-28T23:59:59.000Z
We present TempDAC, a 3-D numerical model for calculating the steady-state temperature distribution for continuous wave laser-heated experiments in the diamond anvil cell. TempDAC solves the steady heat conduction equation in three dimensions over the sample chamber, gasket, and diamond anvils and includes material-, temperature-, and direction-dependent thermal conductivity, while allowing for flexible sample geometries, laser beam intensity profile, and laser absorption properties. The model has been validated against an axisymmetric analytic solution for the temperature distribution within a laser-heated sample. Example calculations illustrate the importance of considering heat flow in three dimensions for the laser-heated diamond anvil cell. In particular, we show that a “flat top” input laser beam profile does not lead to a more uniform temperature distribution or flatter temperature gradients than a wide Gaussian laser beam.
Huang, Xun
19th. AIAA-CEAS Aeroacoutics Conference, May 28th 2013, Berlin Dynamic Modeling and Numerical was presented in this paper. By this control-oriented model, transient dynamic process of multi-physics coupling problem in a progressive wave tube could be approximately studied. The proposed model is verified
place. 2. The basic model can be varied to suit foragers that optimise either their rate of net energy uptake or their foraging ef®ciency. 3. The model requires speci®cation of the time and energy budgetsAn economic model of the limits to foraging range in central place foragers with numerical
NUMERICAL MODELLING OF MICROORGANISMS DISPERSION IN URBAN AREA: APPLICATION TO LEGIONELLA.
Paris-Sud XI, UniversitÃ© de
with transmission of an infectious agent from cooling towers (CT). During the episode that occured in Pas to contaminated cooling towers system may occur over distance larger than 10km. In addition, most cooling towers dispersion from a virtual cooling tower at the same location. The biological model has been activated
Colonius, Tim
of Technology, Pasadena, California 91125 ABSTRACT We develop a reduced order model for large-scale unsteadiness mass injection can pinch off vortices with a smaller size; accordingly, their convective velocity
active region model: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
model (Wheatland and Glukhov 1998; Wheatland 2008; Wheatland 2009). The magnetic free energy of the model active region varies in time due to a prescribed (deterministic)...
Paik, Joongcheol [University of Minnesota; Sotiropoulos, Fotis [University of Minnesota; Sale, Michael J [ORNL
2005-06-01T23:59:59.000Z
A numerical method is developed for carrying out unsteady Reynolds-averaged Navier-Stokes (URANS) simulations and detached-eddy simulations (DESs) in complex 3D geometries. The method is applied to simulate incompressible swirling flow in a typical hydroturbine draft tube, which consists of a strongly curved 90 degree elbow and two piers. The governing equations are solved with a second-order-accurate, finite-volume, dual-time-stepping artificial compressibility approach for a Reynolds number of 1.1 million on a mesh with 1.8 million nodes. The geometrical complexities of the draft tube are handled using domain decomposition with overset (chimera) grids. Numerical simulations show that unsteady statistical turbulence models can capture very complex 3D flow phenomena dominated by geometry-induced, large-scale instabilities and unsteady coherent structures such as the onset of vortex breakdown and the formation of the unsteady rope vortex downstream of the turbine runner. Both URANS and DES appear to yield the general shape and magnitude of mean velocity profiles in reasonable agreement with measurements. Significant discrepancies among the DES and URANS predictions of the turbulence statistics are also observed in the straight downstream diffuser.
Cheng, C. L.; Gragg, M. J.; Perfect, E.; White, Mark D.; Lemiszki, P. J.; McKay, L. D.
2013-08-24T23:59:59.000Z
Numerical simulations are widely used in feasibility studies for geologic carbon sequestration. Accurate estimates of petrophysical parameters are needed as inputs for these simulations. However, relatively few experimental values are available for CO2-brine systems. Hence, a sensitivity analysis was performed using the STOMP numerical code for supercritical CO2 injected into a model confined deep saline aquifer. The intrinsic permeability, porosity, pore compressibility, and capillary pressure-saturation/relative permeability parameters (residual liquid saturation, residual gas saturation, and van Genuchten alpha and m values) were varied independently. Their influence on CO2 injection rates and costs were determined and the parameters were ranked based on normalized coefficients of variation. The simulations resulted in differences of up to tens of millions of dollars over the life of the project (i.e., the time taken to inject 10.8 million metric tons of CO2). The two most influential parameters were the intrinsic permeability and the van Genuchten m value. Two other parameters, the residual gas saturation and the residual liquid saturation, ranked above the porosity. These results highlight the need for accurate estimates of capillary pressure-saturation/relative permeability parameters for geologic carbon sequestration simulations in addition to measurements of porosity and intrinsic permeability.
Numerical Modeling of Thermal EOR: Comprehensive Coupling of an AMR-Based Model
Paris-Sud XI, Université de
Flow and Geomechanics N. Guy*, G. Enchéry and G. Renard IFP Energies nouvelles, 1-4 avenue de Bois of Thermal EOR: Comprehensive Coupling of an AMR-Based Model of Thermal Fluid Flow and Geomechanics when both thermal fluid flow and geomechanics are coupled in order to take into account variations
IMPROVEMENTS IN MODELLING DISSOLVED OXYGEN IN ACTIVATED SLUDGE SYSTEMS
Wells, Scott A.
1 IMPROVEMENTS IN MODELLING DISSOLVED OXYGEN IN ACTIVATED SLUDGE SYSTEMS Jacek Makinia*, Scott A in a full-scale activated sludge reactor. The Activated Sludge Model No. 1 was used to describe for dissolved oxygen. KEYWORDS Activated sludge; dispersion; dissolved oxygen dynamics; mass transfer
Theory and modeling of active brazing.
van Swol, Frank B.; Miller, James Edward; Lechman, Jeremy B.; Givler, Richard C.
2013-09-01T23:59:59.000Z
Active brazes have been used for many years to produce bonds between metal and ceramic objects. By including a relatively small of a reactive additive to the braze one seeks to improve the wetting and spreading behavior of the braze. The additive modifies the substrate, either by a chemical surface reaction or possibly by alloying. By its nature, the joining process with active brazes is a complex nonequilibrium non-steady state process that couples chemical reaction, reactant and product diffusion to the rheology and wetting behavior of the braze. Most of the these subprocesses are taking place in the interfacial region, most are difficult to access by experiment. To improve the control over the brazing process, one requires a better understanding of the melting of the active braze, rate of the chemical reaction, reactant and product diffusion rates, nonequilibrium composition-dependent surface tension as well as the viscosity. This report identifies ways in which modeling and theory can assist in improving our understanding.
Khangaonkar, Tarang; Yang, Zhaoqing; Kim, Tae Yun; Roberts, Mindy
2011-07-20T23:59:59.000Z
Through extensive field data collection and analysis efforts conducted since the 1950s, researchers have established an understanding of the characteristic features of circulation in Puget Sound. The pattern ranges from the classic fjordal behavior in some basins, with shallow brackish outflow and compensating inflow immediately below, to the typical two-layer flow observed in many partially mixed estuaries with saline inflow at depth. An attempt at reproducing this behavior by fitting an analytical formulation to past data is presented, followed by the application of a three-dimensional circulation and transport numerical model. The analytical treatment helped identify key physical processes and parameters, but quickly reconfirmed that response is complex and would require site-specific parameterization to include effects of sills and interconnected basins. The numerical model of Puget Sound, developed using unstructured-grid finite volume method, allowed resolution of the sub-basin geometric features, including presence of major islands, and site-specific strong advective vertical mixing created by bathymetry and multiple sills. The model was calibrated using available recent short-term oceanographic time series data sets from different parts of the Puget Sound basin. The results are compared against (1) recent velocity and salinity data collected in Puget Sound from 2006 and (2) a composite data set from previously analyzed historical records, mostly from the 1970s. The results highlight the ability of the model to reproduce velocity and salinity profile characteristics, their variations among Puget Sound subbasins, and tidally averaged circulation. Sensitivity of residual circulation to variations in freshwater inflow and resulting salinity gradient in fjordal sub-basins of Puget Sound is examined.
Boyer, Edmond
Introduction Flattening the Earth Continuation procedure Flat Earth Numerical simulations Continuation from a flat to a round Earth model in the coplanar orbit transfer problem M. Cerf1, T. Haberkorn, SADCO 2011, March 2nd M. Cerf, T. Haberkorn, E. Tr´elat Continuation from a flat to a round Earth model
Paris-Sud XI, Université de
1 Numerical modelling of hybrid arc/laser welding: a Level Set approach for weld bead formation.Bellet@mines-paristech.fr ABSTRACT The joining of high thickness steel sheets by means of hybrid Laser/GMAW welding processes of the workpiece borders. Two finite elements models are presented to illustrate: (i) A hybrid arc/laser welding
An efficient numerical model for incompressible two-phase flow in fractured media Hussein Hoteit a,1
Firoozabadi, Abbas
in fractured hydrocarbon reservoirs [16]. In this model, the matrixfracture mass transfer is describedAn efficient numerical model for incompressible two-phase flow in fractured media Hussein Hoteit a,1 , Abbas Firoozabadi a,b,* a Reservoir Engineering Research Institute, Palo Alto, CA, USA b Yale
Beaumont, Christopher
Numerical Modeling of Salt Tectonics on Passive Continental Margins: Preliminary Assessment Sciences The University of Leeds LS2 9JT Leeds United Kingdom Abstract Salt tectonics in passive model of frictional-plastic sedimentary overburden overlying a linear viscous salt layer. We present
Paris-Sud XI, Université de
Stochastic reduced-order model for an automotive vehicle in presence of numerous local elastic a high modal density in the low-frequency range, such as an automotive vehicle. This type of structure is applied on a complex computational model of an automotive vehicle. 1 INTRODUCTION This work is performed
Numerical-model developments for stimulation technologies in the Eastern Gas Shales Project
Barbour, T.G.; Maxwell, D.E.; Young, C.
1980-01-01T23:59:59.000Z
These efforts were directed towards the development of a numerical tensile failure model that could be used to make a parameter sensitivity study of the EGSP wellbore stimulation methods for gas recovery in Devonain shales, calculations were performed using the NTS Multi-Frac Mineback Experiments as the geometry, boundary conditions and material properties of the models. Several major accomplishments were achieved during this task. These include: development of a Crack and Void Strain (CAVS) tensile failure model for one-dimensional fracture analysis using the one-dimensional geometries available in SAI's STEALTH 1-D finite-difference code; modification of the original CAVS tensile failure criteria to improve its representation of multiple fracture development by introducing a logic that adjusts the material's tensile strength (both for crack initiation and crack propagation) according to the degree of cracking that has occurred; adding a submodel to CAVS to allow for cracking propping when a crack is reclosed and to require energy to be expanded during this process; adding a submodel to CAVS to allow for crack pressurization when a crack void strain is in communication with the fluid pressure of the borehole; and performing a parameter sensitivity analysis to determine the effect that the material properties of the rock has on crack development, to include the effects of yielding and compaction. Using the CAVS model and its submodels, a series of STEALTH calculations were then performed to estimate the response of the NTS unaugmented Dynafrac experiment. Pressure, acceleration and stress time histories and snapshot data were obtained and should aid in the evaluation of these experiments. Crack patterns around the borehole were also calculated and should be valuable in a comparison with the fracture patterns observed during mineback.
Kaczmarski, Krzysztof [University of Tennessee and Rzeszow University of Technology, Poland; Guiochon, Georges A [ORNL
2011-01-01T23:59:59.000Z
In supercritical fluid chromatography (SFC), the significant expansion of the mobile phase along the column causes the formation of axial and radial gradients of temperature. Due to these gradients, the mobile phase density, its viscosity, its velocity, its diffusion coefficients, etc. are not constant throughout the column. This results in a nonuniform flow velocity distribution, itself causing a loss of column efficiency in certain cases, even at low flow rates, as they do in HPLC. At high flow rates, an important deformation of the elution profiles of the sample components may occur. The model previously used to account satisfactorily for the retention of an unsorbed solute in SFC is applied to the modeling of the elution peak profiles of retained compounds. The numerical solution of the combined heat and mass balance equations provides the temperature and the pressure profiles inside the column and values of the retention time and the band profiles of retained compounds that are in excellent agreement with independent experimental data for large value of mobile phase reduced density. At low reduced densities, the band profiles can strongly depend on the column axial distribution of porosity.
A numerical model of aerosol scavenging. Part 2, Simulation of a large city fire
Bradley, M.M.; Molenkamp, C.R.
1991-10-01T23:59:59.000Z
Using a three-dimensional numerical cloud/smoke-plume model, we have simulated the burning of a large, mid-latitude city following a nuclear exchange. The model includes 18 dynamic and microphysical equations that predict the fire-driven airflow, cloud processes, and smoke-cloud interactions. In the simulation, the intense heating from the burning city produces a firestorm with updraft velocities exceeding 60 m/s. Within 15 minutes of ignition, the smoke plume penetrates the tropopause. The updraft triggers a cumulonimbus cloud that produces significant quantities of ice, snow, and hail. These solid hydrometeors, as well as cloud droplets and rain, interact with the smoke particles from the fire. At the end of the one-hour simulation, over 20% of the smoke is in slowly falling snowflakes. If the snow reaches the ground before the flakes completely sublimate (or melt and then evaporate), then only approximately 50% of the smoke will survive the scavenging processes and remain in the atmosphere to affect the global climate.
Eckert, Andreas
2013-05-31T23:59:59.000Z
In this project generic anticline structures have been used for numerical modeling analyses to study the influence of geometrical parameters, fluid flow boundary conditions, in situ stress regime and inter-bedding friction coefficient on geomechanical risks such as fracture reactivation and fracture generation. The resulting stress states for these structures are also used to determine safe drilling directions and a methodology for wellbore trajection optimization is developed that is applicable for non-Andersonian stress states. The results of the fluid flow simulation show that the type of fluid flow boundary condition is of utmost importance and has significant impact on all injection related parameters. It is recommended that further research is conducted to establish a method to quantify the fluid flow boundary conditions for injection applications. The results of the geomechanical simulation show that in situ stress regime is a crucial, if not the most important, factor determining geomechanical risks. For extension and strike slip stress regimes anticline structures should be favored over horizontally layered basin as they feature higher ?P{sub c} magnitudes. If sedimentary basins are tectonically relaxed and their state of stress is characterized by the uni-axial strain model the basin is in exact frictional equilibrium and fluids should not be injected. The results also show that low inter bedding friction coefficients effectively decouple layers resulting in lower ?P{sub c} magnitudes, especially for the compressional stress regime.
Activities and Accomplishments in Model Year 2007
Not Available
2008-09-01T23:59:59.000Z
Document summarizes the compliance activity of EPAct-covered state and alternative fuel provider fleets.
Models and Technologies Activation of Peroxisome Proliferator-Activated Receptor-
Omiecinski, Curtis
of PPAR-b/d caused a decrease in cell proliferation in MCF7 and MDA-MB-231 cells compared with controls, whereas ligand activation of PPAR-b/d further inhibited proliferation of MCF7 but not MDA-MB-231 cells. Overexpression and/or ligand activation of PPAR-b/d in MDA-MB-231 or MCF7 cells had no effect on experimental
Sensitivity of Optimal Operation of an Activated Sludge Process Model
Skogestad, Sigurd
Sensitivity of Optimal Operation of an Activated Sludge Process Model Antonio Araujo, Simone sensitivity analysis of optimal operation conducted on an activated sludge process model based on the test.[7] applied a systematic procedure for control structure design of an activated sludge process
Active manipulation of fields modeled by the Helmholtz Daniel Onofrei
Onofrei, Daniel
Active manipulation of fields modeled by the Helmholtz equation Daniel Onofrei May 27, 2014, now exterior active sources, modeled with the help of the above boundary controls (which can represent of active control in the context of scalar Helmholtz equation. Given a source region Da and {v0, v1, ..., vn
Active manipulation of fields modeled by the Helmholtz Daniel Onofrei
Onofrei, Daniel
Active manipulation of fields modeled by the Helmholtz equation Daniel Onofrei October 27, 2014 exterior active sources, modeled with the help of the above boundary controls (which can represent velocity]) uses a discrete number of active sources located in the exterior of the control region to manipulate
Numerical Realization of a Shell Model for Impurity Spreading in Plasmas
Tokar, M. Z.; Koltunov, M. [Institute for Energy and Climate Research-Plasma Physics, Research Center Juelich GmbH, Juelich, 52428 (Germany)
2011-09-14T23:59:59.000Z
In plasmas of fusion devices impurity particles are released as a consequence of wall erosion and are seeded deliberately for diverse purposes. Often they enter the plasma volume from small spots and spread away both along and perpendicular to the magnetic field. This process is described by continuity, motion and heat balance equations taking into account such physical processes as ionization by electrons, friction and heating in coulomb collisions with background ions, etc. In present paper we introduce a shell model where solutions of these equations, such as the densities of different impurity ions, are approximated by functions decaying exponentially from the source region due to the ionization into higher charged states. By integrating the original transport equations over several space regions, we get a set of ordinary differential equations describing the time evolution of the characteristic values for the impurity ion densities, fluxes, temperatures, and the dimensions along and across the magnetic field of the clouds where different states are predominantly localized. The equations obtained include time derivatives of complex non-linear combinations of the variables in question. Two numerical approaches to solve such equations are elaborated and compared by considering the spreading of lithium particles in deuterium plasma.
Paradkar, B. S.; Cros, B.; Maynard, G. [Laboratoire de Physique des Gaz et des Plasmas, University Paris Sud 11-CNRS, Orsay (France)] [Laboratoire de Physique des Gaz et des Plasmas, University Paris Sud 11-CNRS, Orsay (France); Mora, P. [Centre de Physique Theorique, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France)] [Centre de Physique Theorique, CNRS, Ecole Polytechnique, 91128 Palaiseau Cedex (France)
2013-08-15T23:59:59.000Z
Numerical modeling of laser wakefield electron acceleration inside a gas filled dielectric capillary tube is presented. Guiding of a short pulse laser inside a dielectric capillary tube over a long distance (?1 m) and acceleration of an externally injected electron bunch to ultra-relativistic energies (?5-10 GeV) are demonstrated in the quasi-linear regime of laser wakefield acceleration. Two dimensional axisymmetric simulations were performed with the code WAKE-EP (Extended Performances), which allows computationally efficient simulations of such long scale plasma. The code is an upgrade of the quasi-static particle code, WAKE [P. Mora and T. M. Antonsen, Jr., Phys. Plasmas 4, 217 (1997)], to simulate the acceleration of an externally injected electron bunch (including beam loading effect) and propagation of the laser beam inside a dielectric capillary. The influence of the transverse electric field of the plasma wake on the radial loss of the accelerated electrons to the dielectric wall is investigated. The stable acceleration of electrons to multi-GeV energy with a non-resonant laser pulse with a large spot-size is demonstrated.
Walter, M.Todd
.53Â0.57 mm and the combustion gas is normal atmospheric pressure air. A detailed numerical simulationOn the spherically symmetrical combustion of methyl decanoate droplets and comparisons Biodiesel Biofuel Microgravity Numerical Droplet combustion a b s t r a c t This study presents
The VOLNA code for the numerical modelling of tsunami waves: generation, propagation and
of the finite volume scheme implemented in the code. We explain the numerical treatment of the wet is decided on the base of inundation maps which are produced with this type of numerical tools. Finally we and the perspectives for future research presented. Key words: tsunami waves, shallow water equations, tsunami
Modeling and Optimizing Ergonomic Activities in Automobile Product Development
da Silva, Alberto Rodrigues
Modeling and Optimizing Ergonomic Activities in Automobile Product Development JoÃ£o Ferreira Anna.silva@acm.org Abstract We collect ergonomic rules and normative rules considerations for automobile business and modeled these activities with a special UML language created for automobile business, VDML (Vehicle Development Modeling
Measuring and modeling activity and travel well-being
Abou Zeid, Maya, 1979-
2009-01-01T23:59:59.000Z
This thesis develops methods for the measurement of activity and travel well-being and models for linking well-being and behavior. The hypotheses underlying this research are that (1) activities are planned to maintain or ...
RodrÃguez, Rodolfo
Numerical analysis of a finite element method for the axisymmetric eddy current model, 27002, Lugo, Spain The aim of this paper is to analyze a finite element method to solve an eddy current of the method are reported. Keywords: low-frequency harmonic Maxwell equations, eddy current problems, finite
Winsor, Peter
), and a numerical polynya model (NPM) forced by National Center for Environmental Predictions (NCEP) wind fields increases to .83. The NPM computes offshore coastal polynya widths, heat exchange, and ice production is that SAR images processed through the SAR polynya algorithm in combination with the NPM is a powerful tool
Harrison, Mark
1988-01-01T23:59:59.000Z
IMA Journal of Numerical Analysis (1988) 8, 415-433 Finite Element Methods for a Model for Full are given and then a discrete-time, explicit finite element procedure is defined and analysed, with finite on the existence, uniqueness and finite element approximation of the solution of Biot's equations were given in [15
Nemat-Nasser, Sia
Numerical modeling of effect of polyurea on response of steel plates to impulsive loads in direct is studied, focusing on the effects of the relative position of polyurea with respect to the loading plates subjected to uniform blast loads and compared their predictions with experimental results. Bahei
Tandon, Amit
Segmentation and Tracking of Mesoscale Eddies in Numeric Ocean Models Vishal Sood, Bin John suggested that the mesoscale eddies and mesoscale features play a strong role in carrying heat poleward oceanographers an invaluable tool to assess mesoscale eddies and the Lagrangian characteristics of this mesoscale
Demouchy, Sylvie
Numerical modelling of erosion processes in the Himalayas of Nepal: effects of spatial variations of the morphology of mountain belts. Here we investigate the modalities of defor- mation in Central Nepal on a c that the pattern of uplift in Nepal is mainly dependent on both erodability and fault geometry, rather than
Barthelat, Francois
Numerical and physical modeling of hydraulic structures Hydraulic structures are used to control, their solution is found either by physical hydraulic modeling or, more recently, by numerical modeling significantly reduce turbine efficiency and cause premature mechanical failure when they occur at hydropower
Witherspoon, P.A.
2010-01-01T23:59:59.000Z
Mathematical modeling of thermal energy storage in aquifers:presented at the Thermal Energy storage in aquifers1979; Aquifer thermal energy storage—a numerical simulation
Modeling Activities in the Department of Energy’s Atmospheric Sciences Program
Fast, Jerome D.; Ghan, Steven J.; Schwartz, Stephen E.
2009-03-01T23:59:59.000Z
The Department of Energy's Atmospheric Science Program (ASP) conducts research pertinent to radiative forcing of climate change by atmospheric aerosols. The program consists of approximately 40 highly interactive peer-reviewed research projects that examine aerosol properties and processes and the evolution of aerosols in the atmosphere. Principal components of the program are instrument development, laboratory experiments, field studies, theoretical investigations, and modeling. The objectives of the Program are to 1) improve the understanding of aerosol processes associated with light scattering and absorption properties and interactions with clouds that affect Earth's radiative balance and to 2) develop model-based representations of these processes that enable the effects of aerosols on Earth's climate system to be properly represented in global-scale numerical climate models. Although only a few of the research projects within ASP are explicitly identified as primarily modeling activities, modeling actually comprises a substantial component of a large fraction of ASP research projects. This document describes the modeling activities within the Program as a whole, the objectives and intended outcomes of these activities, and the linkages among the several modeling components and with global-scale modeling activities conducted under the support of the Department of Energy's Climate Sciences Program and other aerosol and climate research programs.
Numerical study of the mass spectrum in the 2D O(3) sigma model with a theta term
B. Alles; A. Papa
2007-11-12T23:59:59.000Z
It has been conjectured that the mass spectrum of the O(3) non-linear sigma model with a theta term in 2 dimensions may possess an excited state, which decays when theta is lowered from pi below a critical value. Since the direct numerical investigation of the model is prevented by a sign problem, we try to infer some information on the mass spectrum at real theta by studying the model at imaginary theta via analytic continuation. A modified Swendsen-Wang cluster algorithm has been introduced to simulate the model with the theta term.
On a one-dimensional shape-memory alloy model in its fast-temperature-activation limit
Eindhoven, Technische Universiteit
On a one-dimensional shape-memory alloy model in its fast-temperature-activation limit Toyohiko describing the motion of a shape-memory alloy spring at a small characteristic time scale, called here fast for shape memory alloys that can capture oscillations and then damp out these oscillations numerically
An evaluation of pocket-model, numerical readout breath alcohol testing instruments
Van Tassel, William Edward
2004-11-15T23:59:59.000Z
Eight small-scale breath alcohol measurement devices were tested for accuracy, precision and the ability to not yield false positive and false negative readings. These pocket-sized breath testers (PMBTs), which provided numerical readout of Br...
Two-dimensional numerical models of open-top hydrothermal convection at high Rayleigh and Nusselt
Wilcock, William
for Nu up to 5060. Solutions are characterized by an unstable bottom thermal boundary layer where equation. To avoid classical numerical artifacts such as nonphysical oscillatory behavior and artificial
A new strategy for discrete element numerical models: 2. Sandbox applications
Sandiford, Mike
and visualized by the modeler. Reliable modeling of geomechanic processes enables the structural interpreter
Draxl, C.; Churchfield, M.; Mirocha, J.; Lee, S.; Lundquist, J.; Michalakes, J.; Moriarty, P.; Purkayastha, A.; Sprague, M.; Vanderwende, B.
2014-06-01T23:59:59.000Z
Wind plant aerodynamics are influenced by a combination of microscale and mesoscale phenomena. Incorporating mesoscale atmospheric forcing (e.g., diurnal cycles and frontal passages) into wind plant simulations can lead to a more accurate representation of microscale flows, aerodynamics, and wind turbine/plant performance. Our goal is to couple a numerical weather prediction model that can represent mesoscale flow [specifically the Weather Research and Forecasting model] with a microscale LES model (OpenFOAM) that can predict microscale turbulence and wake losses.
Bradley, M.M.; Peterson, K.R.; Rodriguez, D.J.
1988-11-17T23:59:59.000Z
During the hours immediately following a nuclear exchange, large fires could inject enormous quantities of smoke into the atmosphere. This smoke, together with dust from surface bursts, would severely restrict visibilities and darken the skies over large areas for days. This, in turn, could impact surface and air operations and systems. These effects could be mitigated by various scavenging mechanisms within the convective clouds that form above the fires. In order to evaluate impacts of post-nuclear-exchange smoke injection, we are developing a three-dimensional numerical smoke plume model (OCTET) to simulate the dynamics and microphysical processes within smoke plumes and convective clouds above large fires. This model is based on the dynamic framework of the Klemp-Wilhelmson (1978) convective storm model and includes parameterizations of scavenging processes. In addition, we are combining results of laboratory research, field experiments, and detailed numerical modeling of cloud microphysical processes in order to better understand smoke scavenging mechanisms. In this brief demonstration of capabilities, we present results from the OCTET model and from a three-dimensional mesoscale model. The smoke plume and fire-induced cloud simulations demonstrate the effects of nucleation scavenging, seasonal variation of atmospheric stability, and various fuel sources. The mesoscale simulations (that use the plume model output as input) demonstrate the mesoscale transport and diffusion of smoke and predict optical depths over the hypothetical target area. No dust effects have been included in these simulations. 2 refs., 8 figs.
Kiryukhin, A.V.; Sugrobov, V.M.
1986-01-21T23:59:59.000Z
The application of the two-dimensional numerical heat-transfer model to the Pauzhetka hydrothermal system allowed us to establish that: (1) a shallow magma body with the anomalous temperature of 700-1000 C and with a volume of 20-30 km{sup 3} may be a heat source for the formation of the Pauzhetka hydrothermal system. (2) The water feeding source of the Pauzhetka hydrothermal system may be meteoric waters which are infiltrated at an average rate of 5-10 kg/s {center_dot} km{sup 2}. The coupling of the numerical heat-transfer model with hydroisotopic data (D,T,{sup 18}O) obtained from the results of testing of exploitation wells, rivers and springs is the basis to understand more clearly the position of recharge areas and the structure of water flows in the hydrothermal system.
Scalar-Scalar Ladder Model in the Unequal-Mass Case. III - Numerical Studies of the P-Wave Case -
Ichio Fukui; Noriaki Setoh
1999-01-21T23:59:59.000Z
The eigenvalue problem for the p-wave bound states formed by two unequal-mass scalar particles through the massive scalar particle exchange is analyzed numerically in the framework of the Bethe-Salpeter ladder model. As in the s-wave case, the eigenvalues of the coupling constant are found to become complex for some mass configurations in some range of the bound state mass. The Bethe-Salpeter amplitudes of the low-lying bound states are also investigated.
Representation of Dormant and Active Microbial Dynamics for Ecosystem Modeling
Wang, Gangsheng [ORNL; Mayes, Melanie [ORNL; Gu, Lianhong [ORNL; Schadt, Christopher Warren [ORNL
2014-01-01T23:59:59.000Z
Dormancy is an essential strategy for microorganisms to cope with environmental stress. However, global ecosystem models typically ignore microbial dormancy, resulting in notable model uncertainties. To facilitate the consideration of dormancy in these large-scale models, we propose a new microbial physiology component that works for a wide range of substrate availabilities. This new model is based on microbial physiological states and the major parameters are the maximum specific growth and maintenance rates of active microbes and the ratio of dormant to active maintenance rates. A major improvement of our model over extant models is that it can explain the low active microbial fractions commonly observed in undisturbed soils. Our new model shows that the exponentially-increasing respiration from substrate-induced respiration experiments can only be used to determine the maximum specific growth rate and initial active microbial biomass, while the respiration data representing both exponentially-increasing and non-exponentially-increasing phases can robustly determine a range of key parameters including the initial total live biomass, initial active fraction, the maximum specific growth and maintenance rates, and the half-saturation constant. Our new model can be incorporated into existing ecosystem models to account for dormancy in microbially-driven processes and to provide improved estimates of microbial activities.
A numerical procedure to model and monitor CO2 sequestration in
Santos, Juan
area of research. o We present a methodology integrating numerical simulation of CO2 -brine o The simultaneous flow of brine and CO2 is described by the well-known Black in the brine but the brine is not allowed to vaporize into the CO2 phase. o This formulation uses
Numerical modeling of observed effective flow behavior in unsaturated heterogeneous sands
Wildenschild, Dorthe
, and a stochastic theory were compared to effective retention and hydraulic conductivity characteristics measured slow a response in the outflow rate. An alternative approach involving a combination of arithmetic, deterministic simulations would demand vast computa- tional resources by requiring an extremely dense numerical
Numerical and analytical modelling of entropy noise in a supersonic nozzle with a shock
Boyer, Edmond
and numerical assessments of the indirect noise generated through a nozzle are presented. The configuration. R¨ohle, F. Thiele, B. Noll, The Entropy Wave Generator (EWG): A reference case on entropy noise, Journal of Sound and Vibration 326 (2009) 574-598] where an entropy wave is generated upstream of a nozzle
LABORATORY-NUMERICAL MODEL COMPARISONS OF CANYON FLOWS: A PARAMETER STUDY.
, but the enhanced viscosities needed to obtain numerical stability give boundary layers that are too wide along length scales, one the fluid depth and another a more narrow boundary-layer-like thickness [O(RoBu-1 is the interaction of an oscillatory, along-slope background current with an isolated canyon incised in an otherwise
Overland flow modelling with the Shallow Water Equation using a well balanced numerical scheme
Paris-Sud XI, UniversitÃ© de
or kinematic waves equations, and using either finite volume or finite difference method. We compare these four show that, for relatively simple configurations, kinematic waves equations solved with finite volume; finite differ- ences scheme; kinematic wave equations; shallow water equations; comparison of numerical
Numerical modeling of extreme rogue waves generated by directional energy focusing
Grilli, StÃ©phan T.
of an overturning rogue wave, and analyze the sensitivity of its geometry and kinematics to water depth and maximum. Keywords: Water waves; Numerical wave tank; Extreme wave kinematics; Rogue waves 1. Introduction finely resolved 3D focused overturning waves and analyze their geometry and kinematics. In this paper, we
Modeling Oscillatory Activity of Endocrine Richard Bertram
Bertram, Richard
Characteristic Patterns of Electrical Activity #12;Fast Bursting Oscillations Simultaneous fast Ca2+ and voltage Bursting Oscillations Slow oscillations of Ca2+ and voltage from an islet... Zhang et al., Biophys. J., 84 exhibits oscillations, suggesting that insulin is secreted in a pulsatile manner. Porksen et al., AJP, 273
De Castro, Carlos Armando
2011-01-01T23:59:59.000Z
In this paper is developed a simple mathematical model of transient heat transfer under soil with plastic mulch in order to determine with numerical studies the influence of different plastic mulches on the soil temperature and the evolutions of temperatures at different depths with time. The governing differential equations are solved by a Galerkin Finite Element Model, taking into account the nonlinearities due to radiative heat exchange between the soil surface, the plastic mulch and the atmosphere. The model was validated experimentally giving good approximation of the model to the measured data. Simulations were run with the validated model in order to determine the optimal combination of mulch optical properties to maximize the soil temperature with a Taguchi's analysis, proving that the material most used nowadays in Colombia is not the optimal and giving quantitative results of the properties the optimal mulch must possess.
Field observations and numerical model experiments for the snowmelt process at a field site
Ohara, N; Kawas, M L
2006-01-01T23:59:59.000Z
a one dimensional heat transfer model is introduced in orderone dimensional heat transfer model is con- venient forHowever, the simple heat transfer model is a useful tool to
Numerical Models of Galaxy Evolution: Black Hole Feedback and Disk Heating
DeBuhr, Jackson Eugene
2012-01-01T23:59:59.000Z
5.4.3 Disk Heating and Velocity Profiles . . . . . . 5.4.41.3 Disk Heating . . . . . . . . . 1.3.1active galactic nuclei heating in elliptical galaxies.
Simplified Modeling of Active Magnetic Regenerators Thomas Burdyny
Victoria, University of
, this technology uses the magnetization and demagnetization of environmentally neutral solid refrigerants ...............................................................................................................1 1.2 Magnetic RefrigerationSimplified Modeling of Active Magnetic Regenerators by Thomas Burdyny BEng., University of Victoria
NUMERICAL MODELING FOR THE FORMATION MECHANISM OF 3D TOPOGRAPHY ON MICROBIAL MAT SURFACES
Patel, Harsh Jay
2013-09-27T23:59:59.000Z
determined. A deterministic model includes both a dynamic model, and a static model. Compared to a deterministic solute diffusion model, a stochastic diffusion model has one or more stochastic elements. Concentration diffusion system formulated... solute diffusion equation, which merely appears in the form of a number line, the quasi-2D solute diffusion equation forms a Cartesian grid system. Also, for the explicit quasi-2D solute diffusion equation (Eq. 4), concentration variation is measured...
Observational and Numerical Modeling Studies of Turbulence on the Texas-Louisiana Continental Shelf
Zhang, Zheng
2013-05-24T23:59:59.000Z
values to CH model values for (a) q= k, (b) P , (c) B, (d) t, (e) 0t, (f) M 2, and (g) N2. . . . . . . . . . . . . . . . . 58 2.19 Ratios of values between the models: (a) SG/CHx; (b) SGx/CH; (c) SG/SGx; (d) CHx... between depths of 6 and 15 m; (b) sum of the turbulent oxygen uxes at the layers. . . . . . . . . . . . . . . . . . . 80 xvii 3.11 (a) observed ; (b) CH modeled ; (c) SG modeled ; (d) observed ; (e) CH modeled ; (f) SG modeled . The SBL and BBL...
Thermodynamic Modeling and Numerical Simulation of Single-Shaft Microturbine Performance
Hao, X.; Zhang, G.; Zhou, J.; Chen, Y.
2006-01-01T23:59:59.000Z
's performance under off-design situations. The proposed model is validated by operational data of a commercially available micro- turbine from a reference. The result shows that the proposed mathematical model can preferably represent the quasi...
Numerical Modeling of Diffusion in Fractured Media for Gas-Injection
Firoozabadi, Abbas
; Arana 2001; Darvish et al. 2006). Coats (1989) has modeled the effect of diffusion in dual- porosity
A numerical model for the coupled long-term evolution of salt marshes and tidal flats
Fagherazzi, Sergio
-shore mudflat model that takes into account tidal effects; Waeles et al. [2004] incor- porated in the same
A Numerical Model for Miscible Displacement of Multi-Component Reactive Species
Paris-Sud XI, UniversitÃ© de
. Azarouala a Water Department/Groundwater and Geochemistry Modeling, BRGM (French Geological Survey) 3 of our approach. Therefore, the model may prove useful for many practical applications. 1. INTRODUCTION Demands to undertake modeling analysis of coupled groundwater ow, solute transport, and reactive water
Not Available
1980-09-01T23:59:59.000Z
Nineteen papers were presented at the workshop on modeling thermohydrologic flow in fractured masses. This workshop was a result of the interest currently being given to the isolation of nuclear wastes in geologic formations. Included in these proceedings are eighteen of the presentations, one abstract and summaries of the panel discussions. The papers are listed under the following categories: introduction; overviews; fracture modelings; repository studies; geothermal models; and recent developments. Eighteen of the papers have been abstracted and indexed.
THE STATE OF THE ART OF NUMERICAL MODELING OF THERMOHYDROLOGIC FLOW IN FRACTURED ROCK MASSES
Wang, J.S.Y.
2013-01-01T23:59:59.000Z
Doughty, 1979a, Aquifer thermal energy storage--a numericalical modeling of thermal energy storage in aquifers.Presented at the Thermal Energy Storage in Aquifers
Numerical simulations of the internal shock model in magnetized relativistic jets of blazars
Rueda-Becerril, Jesus M; Aloy, Miguel A
2015-01-01T23:59:59.000Z
The internal shocks scenario in relativistic jets is used to explain the variability of the blazar emission. Recent studies have shown that the magnetic field significantly alters the shell collision dynamics, producing a variety of spectral energy distributions and light-curves patterns. However, the role played by magnetization in such emission processes is still not entirely understood. In this work we numerically solve the magnetohydodynamic evolution of the magnetized shells collision, and determine the influence of the magnetization on the observed radiation. Our procedure consists in systematically varying the shell Lorentz factor, relative velocity, and viewing angle. The calculations needed to produce the whole broadband spectral energy distributions and light-curves are computationally expensive, and are achieved using a high-performance parallel code.
Buckholtz, H.T.; Biermann, A.H.
1980-01-01T23:59:59.000Z
A computational model to simulate the dispersion and coagulation of aerosols emitted from coal-fired power plants was constructed. In modeling the dispersion of the aerosol, turbulent diffusion and wind-driven advection are treated by a finite-difference method. Molecular coagulation is incorporated in the model to follow shifts in the particle-size distribution. Particulate coagulation is mathematically described by Timiskii's equation. The relevent semi-empirical work of Smirnov is incorporated in the model to provide for the coagultion constant. Input for the model is a bimodal, particle-size distribution measured at an operating coal-fired power plant. Simulations indicate that dispersion competes against coagulation mechanisms to maintain the bimodal shaped distribution for 32 km. Turbulence and particle settling tend to enchance coagulation effects. The size-dependent spatial segregation of particles within the plume is predicted.
Modelling the polarization dichotomy of Active Galactic Nuclei
Rene W. Goosmann
2007-12-12T23:59:59.000Z
I present polarization modelling of Active Galactic Nuclei in the optical/UV range. The modelling is conducted using the Monte-Carlo radiative transfer code Stokes, which self-consistently models the polarization signature of a complex model arrangement for an active nucleus. In this work I include three different scattering regions around the central source: an equatorial electron scattering disk, an equatorial obscuring dusty torus, and polar electron scattering cones. I investigate the resulting dependencies of the V-band polarization for different optical depths of the scattering cones, different dust compositions inside the torus, and various half-opening angles of the torus/polar cones. The observed polarization dichotomy can be successfully reproduced by the model.
Lusk, Miriam Beatriz
2011-12-31T23:59:59.000Z
To capture the fracture process and non-linear behavior at the element and structural level of granular materials, concrete, under the presence of pre-existing imperfections, a constitutive model and a mesh free method is ...
Airborne observations and numerical modeling of fetch- limited waves in the Gulf of Tehuantepec
Romero, Leonel
2008-01-01T23:59:59.000Z
velocity scaling in wind wave generation. Boundary-Layerlinear theory of of wind wave generation applied to waveSource terms in a third-generation wind wave model. J. Phys.
Numerical Modeling of Fractured Shale-Gas and Tight-Gas Reservoirs Using Unstructured Grids
Olorode, Olufemi Morounfopefoluwa
2012-02-14T23:59:59.000Z
Various models featuring horizontal wells with multiple induced fractures have been proposed to characterize flow behavior over time in tight gas and shale gas systems. Currently, there is little consensus regarding the effects of non...
Numerical Modeling of the Transient Thermal Interference of Vertical U-Tube Haet Exchangers
Muraya, Norman K.
1994-01-01T23:59:59.000Z
Non-linear finite element models were developed to simulate transient heat and mass transfer in the soil surrounding the ground heat exchangers of ground-coupled heat pumps (GCHPs) operating in the cooling mode. Parametric studies were performed...
NUMERICAL MODELING FOR THE FORMATION MECHANISM OF 3D TOPOGRAPHY ON MICROBIAL MAT SURFACES
Patel, Harsh Jay
2013-09-27T23:59:59.000Z
, an innovative modeling approach was employed that focuses on the interface growth of the microbial mat surfaces using a combined stochastic and deterministic approach. A range of different initial conditions were simulated to evaluate the 3D topography evolution...
THE STATE OF THE ART OF NUMERICAL MODELING OF THERMOHYDROLOGIC FLOW IN FRACTURED ROCK MASSES
Wang, J.S.Y.
2013-01-01T23:59:59.000Z
studies related to the Cerro Prieto Field: Proceedings, 1stSymposium on the Cerro Prieto Geothermal Field, San Diego,modeling studies of the Cerro Prieto Reservoir--A progress
Paris-Sud XI, Université de
of underground storage facilities for nuclear waste. The processes involved in near-field models are extremely field u : [0, T ] × R3 and a pressure field p : [0, T ] × R such that - ·(u) + b p = f, in [0
Zeng, Yi
Mathematical models of batteries which make use of the intercalation of a species into a solid phase need to solve the corresponding mass transfer problem. Because solving this equation can significantly add to the ...
Numerical Modeling of the Transient Thermal Interference of Vertical U-Tube Haet Exchangers
Muraya, Norman K.
Non-linear finite element models were developed to simulate transient heat and mass transfer in the soil surrounding the ground heat exchangers of ground-coupled heat pumps (GCHPs) operating in the cooling mode. Parametric studies were performed...
Cirpka, Olaf Arie
vicinity Abandoned wellCO2 2 #12;University of Stuttgart IWS, Department of Hydromechanics and Modelling discretization cap rock precipitated calcite reservoir radius of several meters injection of bacteria, urea
Numerical modeling of fluid flow and time-lapse seismics to monitor ...
santos
May 30, 2014 ... including the presence of shale seals and fractures and fractal variations of the ... In the Black-Oil model employed, brine is NOT present, OIL is.
Numerical and analytical modeling of heat transfer between fluid and fractured rocks
Li, Wei, S.M. Massachusetts Institute of Technology
2014-01-01T23:59:59.000Z
Modeling of heat transfer between fluid and fractured rocks is of particular importance for energy extraction analysis in EGS, and therefore represents a critical component of EGS design and performance evaluation. In ...
Final Report: A Model Management System for Numerical Simulations of Subsurface Processes
Zachmann, David
2013-10-07T23:59:59.000Z
The DOE and several other Federal agencies have committed significant resources to support the development of a large number of mathematical models for studying subsurface science problems such as groundwater flow, fate of contaminants and carbon sequestration, to mention only a few. This project provides new tools to help decision makers and stakeholders in subsurface science related problems to select an appropriate set of simulation models for a given field application.
and free surface models and a global heat transfer model, with moving boundaries. An axisymmetric fluid to determine flow field, after the phase boundaries have been determined, by the heat transfer model. A finite field, from which temperature gradients are determined. The heat transfer model is furthermore expanded
Min, Kyoung
2013-07-16T23:59:59.000Z
are studied using a coupled thermo-hydro-mechanical (THM) analysis. The models are used to simulate microscopic and macroscopic fracture behaviors of laboratory-scale uniaxial and triaxial experiments on rock using an elastic/brittle damage model considering...
Synthesis of Numerical Methods for Modeling Wave Energy Converter-Point Absorbers: Preprint
Li, Y.; Yu, Y. H.
2012-05-01T23:59:59.000Z
During the past few decades, wave energy has received significant attention among all ocean energy formats. Industry has proposed hundreds of prototypes such as an oscillating water column, a point absorber, an overtopping system, and a bottom-hinged system. In particular, many researchers have focused on modeling the floating-point absorber as the technology to extract wave energy. Several modeling methods have been used such as the analytical method, the boundary-integral equation method, the Navier-Stokes equations method, and the empirical method. However, no standardized method has been decided. To assist the development of wave energy conversion technologies, this report reviews the methods for modeling the floating-point absorber.
Numerical model for the vacuum pyrolysis of scrap tires in batch reactors
Yang, J.; Tanguy, P.A.; Roy, C. [Univ. Laval, Quebec, PQ (Canada). Dept. de Genie Chimique] [Univ. Laval, Quebec, PQ (Canada). Dept. de Genie Chimique
1995-06-01T23:59:59.000Z
A quantitative model for scrap tire pyrolysis in a batch scale reactor developed comprises the following basic phenomena: conduction inside tire particles; conduction, convection, and radiation between the feedstock particles or between the fluids and the particles; tire pyrolysis reaction; exothermicity and endothermicity caused by tire decomposition and volatilization; and the variation of the composition and the thermal properties of tire particles. This model was used to predict the transient temperature and density distributions in the bed of particles, the volatile product evolution rate, the mass change, the energy consumption during the pyrolysis process, and the pressure history in a tire pyrolysis reactor with a load of 1 kg. The model predictions agree well with independent experimental data.
None
2005-07-01T23:59:59.000Z
This work was carried out to understand the behavior of the solid and gas phases in a CFB riser. Only the riser is modeled as a straight pipe. A model with linear algebraic approximation to solids viscosity of the form, {musubs} = 5.34{epsisubs}, ({espisubs} is the solids volume fraction) with an appropriate boundary condition at the wall obtained by approximate momentum balance solution at the wall to acount for the solids recirculation is tested against experimental results. The work done was to predict the flow patterns in the CFB risers from available experimental data, including data from a 7.5-cm-ID CFB riser at the Illinois Institute of Technology and data from a 20.0-cm-ID CFB riser at the Particulate Solid Research, Inc., facility. This research aims at modeling the removal of hydrogen sulfide from hot coal gas using zinc oxide as the sorbent in a circulating fluidized bed and in the process indentifying the parameters that affect the performance of the sulfidation reactor. Two different gas-solid reaction models, the unreacted shrinking core (USC) and the grain model were applied to take into account chemical reaction resistances. Also two different approaches were used to affect the hydrodynamics of the process streams. The first model takes into account the effect of micro-scale particle clustering by adjusting the gas-particle drag law and the second one assumes a turbulent core with pseudo-steady state boundary condition at the wall. A comparison is made with experimental results.
Numerical Modelling of a Pulse Combustion Burner: Limiting Conditions of Stable
Vuik, Kees
-called thermal pulse combustor. By integrating the model equations in time it is possible to predict whether A thermal pulse combustion. Figure 1 gives a schematic representation of such a thermal pulse combustor combustors may give important guide- lines on how design parameters should be chosen. This paper gives
Model Validation and Spatial Interpolation by Combining Observations with Outputs from Numerical
Washington at Seattle, University of
""r,c,rn The authors are for hel]JfuI #12;Abstract Constructing maps of pollution levels is vital for air quality concentrations. Key tlJords: air pollution, Ba~yesian inference, change of support, likelihood approaches, Matern Resolutions 2.5 Modeling a Nonstationary Covariance . 3 Estimation 3.1 Algorithm 4 Application: Air Pollution
A numerical procedure to model and monitor CO2 sequestration in
Santos, Juan
sequestration over very long periods of time. · The analysis of CO2 underground storage safety in the long term procedure to model and monitor CO2 sequestration in aquifers p. #12;Introduction. I · Storage of CO2 (31.6C, 7.38 MPa). · First industrial scale CO2 injection project: Sleipner gas field (North Sea
A numerical procedure to model and monitor CO2 sequestration in aquifers
Santos, Juan
sequestration over very long periods of time. The analysis of CO2 underground storage safety in the long term procedure to model and monitor CO2 sequestration in aquifers p. #12;Introduction. I Storage of CO2 (31.6C, 7.38 MPa). First industrial scale CO2 injection project: Sleipner gas field (North Sea
A multiple layer numerical model of the formation of the low-level jet
Shen, Tsu-Cheng
1980-01-01T23:59:59.000Z
310 320 e(kj Fig. 3. The initial vertical distribution of potential tempera- ture in the model . Table 3. The vertical distribution of the variables used for setting the initial conditions. LEVEL k (m s ) kh(m s ) u(ms ) v(ms ) w(ms ) e (k) 00 p...
Evaluation of a semi-implicit numerical algorithm for a rate-dependent ductile failure model.
Zocher, M. A. (Marvin Anthony); Zuo, Q. K. (Qiuhai K.); Mason, T. A. (Thomas A.)
2002-09-01T23:59:59.000Z
A survey conducted in the mid-80's revealed that the mathematical descriptions of ductile fracture tended to apply to either tensile tests or spa11 tests. The objective behind the development of the TEPLA was then a unification of these disparate phenomena into a single model.
Experimental Validation of a Numerical Multizone Airflow and Pollutant Transfer Model
Paris-Sud XI, Université de
and long-term assessment of the performances of ventilation systems, the experimental house MARIA and ventilation systems are modeled in MATLAB/Simulink environment. This paper quickly describes the multi exhaust, balanced and natural ventilation systems. In addition, the virtual laboratory SIMBAD Building
Numerical Modeling of Nonlinear Coupling between Lines/Beams with Multiple Floating Bodies
Yang, Chan K.
2010-07-14T23:59:59.000Z
to be capable of modeling the tendon disconnection both at the top and the bottom connection as well as the down stroke behavior for the pinned bottom joint. The performance of the tie-down clamp of derrick is also investigated by using six degrees of freedom...
Numerical Modeling At Dixie Valley Geothermal Area (McKenna & Blackwell,
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer PlantMunhall,Missouri: EnergyExcellence Seed LLCShores,ActivityNufcorEnergy2003) | Open
Numerical Modeling At Lightning Dock Geothermal Area (O'Brien, Et Al.,
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer PlantMunhall,Missouri: EnergyExcellence Seed LLCShores,ActivityNufcorEnergy2003) | Open1984)
Numerical Modeling At Neal Hot Springs Geothermal Area (U.S. Geothermal
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov YouKizildere I Geothermal Pwer PlantMunhall,Missouri: EnergyExcellence Seed LLCShores,ActivityNufcorEnergy2003) |
Non-equilibrium structure and dynamics in a microscopic model of thin film active gels
D. A. Head; W. J. Briels; G. Gompper
2014-02-26T23:59:59.000Z
In the presence of ATP, molecular motors generate active force dipoles that drive suspensions of protein filaments far from thermodynamic equilibrium, leading to exotic dynamics and pattern formation. Microscopic modelling can help to quantify the relationship between individual motors plus filaments to organisation and dynamics on molecular and supra-molecular length scales. Here we present results of extensive numerical simulations of active gels where the motors and filaments are confined between two infinite parallel plates. Thermal fluctuations and excluded-volume interactions between filaments are included. A systematic variation of rates for motor motion, attachment and detachment, including a differential detachment rate from filament ends, reveals a range of non-equilibrium behaviour. Strong motor binding produces structured filament aggregates that we refer to as asters, bundles or layers, whose stability depends on motor speed and differential end-detachment. The gross features of the dependence of the observed structures on the motor rate and the filament concentration can be captured by a simple one-filament model. Loosely bound aggregates exhibit super-diffusive mass transport, where filament translocation scales with lag time with non-unique exponents that depend on motor kinetics. An empirical data collapse of filament speed as a function of motor speed and end-detachment is found, suggesting a dimensional reduction of the relevant parameter space. We conclude by discussing the perspectives of microscopic modelling in the field of active gels.
Numerical study of three-dimensional PIC for the surface plasmon excitation based on Drude model
Liu, La-Qun; Wang, Hui-Hui; Liu, Da-Gang
2015-01-01T23:59:59.000Z
This paper explores the time-domain equations of noble metals, in which Drude model is adopted to describe the dielectric constant, to implement three-dimensional particle-in-cell (PIC) simulations for the surface plasmon excitation with the finite-difference time-domain method (FDTD). A three-dimensional model for an electron bunch movement near the metal film is constructed, and particle-in-cell (PIC) simulations are carried out with various metal films of different thicknesses. The frequency of surface plasmon obtained from PIC simulation is agreed with that from theory. Furthermore, the surface plasmon wave properties of excitation and propagation with the metal film is summarized by PIC results.
Pham, VT.; Silva, L.; Digonnet, H.; Combeaud, C.; Billon, N.; Coupez, T. [Centre for Material Forming (CEMEF), MINES ParisTech, Rue Claude Daunesse, Sophia Antipolis cedex (France)
2011-05-04T23:59:59.000Z
The objective of this work is to model the viscoelastic behaviour of polymer from the solid state to the liquid state. With this objective, we perform experimental tensile tests and compare with simulation results. The chosen polymer is a PMMA whose behaviour depends on its temperature. The computation simulation is based on Navier-Stokes equations where we propose a mixed finite element method with an interpolation P1+/P1 using displacement (or velocity) and pressure as principal variables. The implemented technique uses a mesh composed of triangles (2D) or tetrahedra (3D). The goal of this approach is to model the viscoelastic behaviour of polymers through a fluid-structure coupling technique with a multiphase approach.
Laboratory experiments and numerical modeling of wave attenuation through artificial vegetation
Augustin, Lauren Nicole
2009-05-15T23:59:59.000Z
). The first hydrodynamic model developed by Price et al. (1968) simulated the effects of seaweed as a high viscous layer. Mork (1996) extended the idea of the high viscous layer and developed a theory for kelp plants that took into account not only viscous... has been validated by artificial laboratory kelp experiments for the species Laminaria Hyperborea, and is assumed appropriate for representing wave transformation and damping over submerged vegetative fields of variable depths. Mork (1996) studied...
Exact theory and numeric results for short pulse ionization of simple model atom in one dimension
Rokhlenko, Alexander
2015-01-01T23:59:59.000Z
Our exact theory for continuous harmonic perturbation of a one dimensional model atom by parametric variations of its potential is generalized for the cases when a) the atom is exposed to short pulses of an external harmonic electric field and b) the forcing is represented by short bursts of different shape changing the strength of the binding potential. This work is motivated not only by the wide use of laser pulses for atomic ionization, but also by our earlier study of the same model which successfully described the ionization dynamics in all orders, i.e. the multi-photon processes, though being treated by the non-relativistic Schr\\"odinger equation. In particular, it was shown that the bound atom cannot survive the excitation of its potential caused by any non-zero frequency and amplitude of the continuous harmonic forcing. Our present analysis found important laws of the atomic ionization by short pulses, in particular the efficiency of ionizing this model system and presumably real ones as well.
Esh, D. W.; Scheetz, B. E.
1999-09-21T23:59:59.000Z
Thermohydrochemical (T-H-C) processes result from the placement of heat-generating radioactive materials in unsaturated, fractured geologic materials. The placement of materials in the proposed Yucca Mountain repository will result in complex environmental conditions. Simple models are developed liking the thermohydrological effects simulated with TOUGHZ to system chemistry, with an example presented for chloride. Perturbations to near-field chemistry could have a significant impact on the migration of actinides and fission products in geologic materials. Various conceptual models to represent fractures are utilized in TOUGHZ simulations of thermohydrological processes. The simulated moisture redistribution is then coupled to simple chemical models to demonstrate the potential magnitude of T-H-C processes. The concentration of chloride in solution (returning to the engineered barrier system) is demonstrated, in extreme cases, to exceed 100,000 mg/L. The implication is that the system (typically ambient chemical and hydrological conditions) in which radionuclide transport is typically simulated and measured may be significantly different from the perturbed system.
Dubus, Guillaume; Fromang, Sébastien
2015-01-01T23:59:59.000Z
Detailed modeling of the high-energy emission from gamma-ray binaries has been propounded as a path to pulsar wind physics. Fulfilling this ambition requires a coherent model of the flow and its emission in the region where the pulsar wind interacts with the stellar wind of its companion. We developed a code that follows the evolution and emission of electrons in the shocked pulsar wind based on inputs from a relativistic hydrodynamical simulation. The code is used to model the well-documented spectral energy distribution and orbital modulations from LS 5039. The pulsar wind is fully confined by a bow shock and a back shock. The particles are distributed into a narrow Maxwellian, emitting mostly GeV photons, and a power law radiating very efficiently over a broad energy range from X-rays to TeV gamma rays. Most of the emission arises from the apex of the bow shock. Doppler boosting shapes the X-ray and VHE lightcurves, constraining the system inclination to $i\\approx 35^{\\rm o}$. There is a tension between th...
Prinja, A.K.
1998-09-01T23:59:59.000Z
In this work, it has been shown that, for the given sets of parameters (transport coefficients), the Tangent-Predictor (TP) continuation method, which was used in the coarsest grid, works remarkably well. The problems in finding an initial guess that resides well within Newton`s method radius of convergence are alleviated by correcting the initial guess by the predictor step of the TP method. The TP method works well also in neutral gas puffing and impurity simulations. The neutral gas puffing simulation is performed by systematically increasing the fraction of puffing rate according to the TP method until it reaches a desired condition. Similarly, the impurity simulation characterized by using the fraction of impurity density as the continuation parameter, is carried out in line with the TP method. Both methods show, as expected, a better performance than the classical embedding (CE) method. The convergence criteria {epsilon} is set to be 10{sup {minus}9} based on the fact that lower value of {epsilon} does not alter the solution significantly. Correspondingly, the number of Newton`s iterations in the corrector step of the TP method decrease substantially, an extra point in terms of code speed. The success of the TP method enlarges the possibility of including other sets of parameters (operations and physics). With the availability of the converged coarsest grid solution, the next forward step to the multigrid cycle becomes possible. The multigrid method shows that the memory storage problems that plagued the application of Newton`s method on fine grids, are of no concern. An important result that needs to be noted here is the performance of the FFCD model. The FFCD model is relatively simple and is based on the overall results the model has shown to predict different divertor plasma parameters. The FFCD model treats exactly the implementation of the deep penetration of energetic neutrals emerging from the divertor plate. The resulting ionization profiles are relatively smooth as a consequence of the less localized recycling, leading to an improved convergence rate of the numerical algorithm. Peak plasma density is lower and the temperature correspondingly higher than those predicted by the standard diffusion model. It is believed that the FFCD model is more accurate. With both the TP continuation and multigrid methods, the author has demonstrated the robustness of these two methods. A mutually beneficial hybridization between the TP method and multigrid methods is clearly an alternative for edge plasma simulation. While the fundamental transport model considered in this work has ignored important physics such as drifts and currents, he has nevertheless demonstrated the versatility and robustness of the numerical scheme to handle such new physics. The application of gaseous-radiative divertor model in this work is just a beginning and up to this point numerically, the future is exciting.
Learning Active Basis Models by EM-Type Algorithms
Wu, Ying Nian
Learning Active Basis Models by EM-Type Algorithms Zhangzhang Si1, Haifeng Gong1,2, Song-Chun Zhu1, and scales as latent variables into the image generation process, and learn the template by EM-type scheme for learning image templates of object categories where the learning is not fully supervised. We
Modeling active electrolocation in weakly electric fish Habib Ammari
Garnier, Josselin
Modeling active electrolocation in weakly electric fish Habib Ammari Thomas Boulier Josselin in weakly electric fishes. We first investigate the forward complex conductivity problem and derive the approx- imate boundary conditions on the skin of the fish. Then we provide a dipole approximation
Detecting Termination of Active Database Rules Using Symbolic Model Checking
Ray, Indrakshi
Detecting Termination of Active Database Rules Using Symbolic Model Checking Indrakshi Ray is the non-termination of rules. Although algorithms have been proposed to detect non-termination, al- most all provide a conservative estimate; that is, the algorithms detect all the potential cases of non-termination
High-Resolution Modeling to Assess Tropical Cyclone Activity in Future Climate Regimes
Lackmann, Gary
2013-06-10T23:59:59.000Z
Applied research is proposed with the following objectives: (i) to determine the most likely level of tropical cyclone intensity and frequency in future climate regimes, (ii) to provide a quantitative measure of uncertainty in these predictions, and (iii) to improve understanding of the linkage between tropical cyclones and the planetary-scale circulation. Current mesoscale weather forecasting models, such as the Weather Research and Forecasting (WRF) model, are capable of simulating the full intensity of tropical cyclones (TC) with realistic structures. However, in order to accurately represent both the primary and secondary circulations in these systems, model simulations must be configured with sufficient resolution to explicitly represent convection (omitting the convective parameterization scheme). Most previous numerical studies of TC activity at seasonal and longer time scales have not utilized such explicit convection (EC) model runs. Here, we propose to employ the moving nest capability of WRF to optimally represent TC activity on a seasonal scale using a downscaling approach. The statistical results of a suite of these high-resolution TC simulations will yield a realistic representation of TC intensity on a seasonal basis, while at the same time allowing analysis of the feedback that TCs exert on the larger-scale climate system. Experiments will be driven with analyzed lateral boundary conditions for several recent Atlantic seasons, spanning a range of activity levels and TC track patterns. Results of the ensemble of WRF simulations will then be compared to analyzed TC data in order to determine the extent to which this modeling setup can reproduce recent levels of TC activity. Next, the boundary conditions (sea-surface temperature, tropopause height, and thermal/moisture profiles) from the recent seasons will be altered in a manner consistent with various future GCM/RCM scenarios, but that preserves the large-scale shear and incipient disturbance activity. This will allow (i) a direct comparison of future TC activity that could be expected for an active or inactive season in an altered climate regime, and (ii) a measure of the level of uncertainty and variability in TC activity resulting from different carbon emission scenarios.
Pruess, K.
1990-03-01T23:59:59.000Z
Hydrologic impacts of corrosive gas release from a hypothetical L/ILW nuclear waste repository at Oberbauenstock are explored by means of numerical simulation. A schematic two dimensional vertical section through the mountain is modeled with the simulator TOUGH, which describes two-phase flow of water and gas in porous and fractured media. Two reference cases are considered which represent the formations as a porous and as a fractured-porous (dual permeability) medium, respectively. Both cases predict similar and rather modest pressure increases, from ambient 10 bars to near 25 bars at the repository level. These results are to be considered preliminary because important parameters affecting two-phase flow, such as relative permeabilities of a fractured medium, are not well known at present. 24 refs., 15 figs., 5 tabs.
Parallel 3D Finite Element Numerical Modelling of DC Electron Guns
Prudencio, E.; Candel, A.; Ge, L.; Kabel, A.; Ko, K.; Lee, L.; Li, Z.; Ng, C.; Schussman, G.; /SLAC
2008-02-04T23:59:59.000Z
In this paper we present Gun3P, a parallel 3D finite element application that the Advanced Computations Department at the Stanford Linear Accelerator Center is developing for the analysis of beam formation in DC guns and beam transport in klystrons. Gun3P is targeted specially to complex geometries that cannot be described by 2D models and cannot be easily handled by finite difference discretizations. Its parallel capability allows simulations with more accuracy and less processing time than packages currently available. We present simulation results for the L-band Sheet Beam Klystron DC gun, in which case Gun3P is able to reduce simulation time from days to some hours.
A numerical model and scaling relationship for energetic electron beams propagating in air
Fernsler, R. F.; Slinker, S. P. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Lambrakos, S. G. [Materials Science and Technology Division, Naval Research Laboratory, Washington, DC 20375 (United States)
2008-09-15T23:59:59.000Z
Scaling relationships for energy loss and scattering are combined with a particle code to construct a purely algebraic expression for the energy deposited by an energetic electron beam injected into field-free homogeneous air. An algebraic formulation is possible because the mean free paths for the major collisional processes depend similarly on density and energy above 1 keV. Accordingly, the spatial behavior of an initially cold pencil beam is approximately self-similar when expressed in terms of the nominal beam range, provided the beam energy at injection exceeds several keV. Since a warm and broad beam can always be decomposed into a series of cold pencil beams, the total energy deposited can be obtained through a simple sum. With such a model, the ionization and excitation generated by a beam can be computed quickly and easily at every point in space. Similar formulations can be developed for other media using particle codes or experimental data. In liquids or solids, the energy deposited is quickly converted to heat and ultimately to melting and/or vaporization of the material.
Nonlinear force-free models for the solar corona I. Two active regions with very different structure
S. Regnier; E. R. Priest
2007-03-29T23:59:59.000Z
With the development of new instrumentation providing measurements of solar photospheric vector magnetic fields, we need to develop our understanding of the effects of current density on coronal magnetic field configurations. The object is to understand the diverse and complex nature of coronal magnetic fields in active regions using a nonlinear force-free model. From the observed photospheric magnetic field we derive the photospheric current density for two active regions: one is a decaying active region with strong currents (AR8151), and the other is a newly emerged active region with weak currents (AR8210). We compare the three-dimensional structure of the magnetic fields for both active region when they are assumed to be either potential or nonlinear force-free. The latter is computed using a Grad-Rubin vector-potential-like numerical scheme. A quantitative comparison is performed in terms of the geometry, the connectivity of field lines, the magnetic energy and the magnetic helicity content. For the old decaying active region the connectivity and geometry of the nonlinear force-free model include strong twist and strong shear and are very different from the potential model. The twisted flux bundles store magnetic energy and magnetic helicity high in the corona (about 50 Mm). The newly emerged active region has a complex topology and the departure from a potential field is small, but the excess magnetic energy is stored in the low corona and is enough to trigger powerful flares.
Mickens, R.E.
1997-12-12T23:59:59.000Z
The major thrust of this proposal was to continue our investigations of so-called non-standard finite-difference schemes as formulated by other authors. These schemes do not follow the standard rules used to model continuous differential equations by discrete difference equations. The two major aspects of this procedure consist of generalizing the definition of the discrete derivative and using a nonlocal model (on the computational grid or lattice) for nonlinear terms that may occur in the differential equations. Our aim was to investigate the construction of nonstandard finite-difference schemes for several classes of ordinary and partial differential equations. These equations are simple enough to be tractable, yet, have enough complexity to be both mathematically and scientifically interesting. It should be noted that all of these equations differential equations model some physical phenomena under an appropriate set of experimental conditions. The major goal of the project was to better understand the process of constructing finite-difference models for differential equations. In particular, it demonstrates the value of using nonstandard finite-difference procedures. A secondary goal was to construct and study a variety of analytical techniques that can be used to investigate the mathematical properties of the obtained difference equations. These mathematical procedures are of interest in their own right and should be a valuable contribution to the mathematics research literature in difference equations. All of the results obtained from the research done under this project have been published in the relevant research/technical journals or submitted for publication. Our expectation is that these results will lead to improved finite difference schemes for the numerical integration of both ordinary and partial differential equations. Section G of the Appendix gives a concise summary of the major results obtained under funding by the grant.
Chiswell, S
2009-01-11T23:59:59.000Z
Assimilation of radar velocity and precipitation fields into high-resolution model simulations can improve precipitation forecasts with decreased 'spin-up' time and improve short-term simulation of boundary layer winds (Benjamin, 2004 & 2007; Xiao, 2008) which is critical to improving plume transport forecasts. Accurate description of wind and turbulence fields is essential to useful atmospheric transport and dispersion results, and any improvement in the accuracy of these fields will make consequence assessment more valuable during both routine operation as well as potential emergency situations. During 2008, the United States National Weather Service (NWS) radars implemented a significant upgrade which increased the real-time level II data resolution to 8 times their previous 'legacy' resolution, from 1 km range gate and 1.0 degree azimuthal resolution to 'super resolution' 250 m range gate and 0.5 degree azimuthal resolution (Fig 1). These radar observations provide reflectivity, velocity and returned power spectra measurements at a range of up to 300 km (460 km for reflectivity) at a frequency of 4-5 minutes and yield up to 13.5 million point observations per level in super-resolution mode. The migration of National Weather Service (NWS) WSR-88D radars to super resolution is expected to improve warning lead times by detecting small scale features sooner with increased reliability; however, current operational mesoscale model domains utilize grid spacing several times larger than the legacy data resolution, and therefore the added resolution of radar data is not fully exploited. The assimilation of super resolution reflectivity and velocity data into high resolution numerical weather model forecasts where grid spacing is comparable to the radar data resolution is investigated here to determine the impact of the improved data resolution on model predictions.
Skogestad, Sigurd
Sensitivity Analysis of Optimal Operation of an Activated Sludge Process Model for Economic operation conducted on an activated sludge process model based on the test-bed benchmark simulation model no. 1 (BSM1) and the activated sludge model no. 1 (ASM1). The objective is to search for a control
11. NUMERICAL TECHNIQUES 1 Numerical identification of effective multipole
Boyer, Edmond
11. NUMERICAL TECHNIQUES 1 Numerical identification of effective multipole moments of polarizable of the induced multipole moments. A general multipole theory is available in the literature, however, only linear multipole model is usually exploited when determining numerically these effective moments. Since this axial
Kaczmarski, Krzysztof [University of Tennessee and Rzeszow University of Technology, Poland; Guiochon, Georges A [ORNL
2010-01-01T23:59:59.000Z
When chromatography is carried out with high-density carbon dioxide as the main component of the mobile phase (a method generally known as 'supercritical fluid chromatography' or SFC), the required pressure gradient along the column is moderate. However, this mobile phase is highly compressible and, under certain experimental conditions, its density may decrease significantly along the column. Such an expansion absorbs heat, cooling the column, which absorbs heat from the outside. The resulting heat transfer causes the formation of axial and radial gradients of temperature that may become large under certain conditions. Due to these gradients, the mobile phase velocity and most physico-chemical parameters of the system (viscosity, diffusion coefficients, etc.) are no longer constant throughout the column, resulting in a loss of column efficiency, even at low flow rates. At high flow rates and in serious cases, systematic variations of the retention factors and the separation factors with increasing flow rates and important deformations of the elution profiles of all sample components may occur. The model previously used to account satisfactorily for the effects of the viscous friction heating of the mobile phase in HPLC is adapted here to account for the expansion cooling of the mobile phase in SFC and is applied to the modeling of the elution peak profiles of an unretained compound in SFC. The numerical solution of the combined heat and mass balance equations provides temperature and pressure profiles inside the column, and values of the retention time and efficiency for elution of this unretained compound that are in excellent agreement with independent experimental data.
Cohen, Andrew J.B.
1999-06-01T23:59:59.000Z
Numerical simulations of groundwater flow at Yucca Mountain, Nevada are used to investigate how the faulted hydrogeologic structure influences groundwater flow from a proposed high-level nuclear waste repository. Simulations are performed using a 3-D model that has a unique grid block discretization to accurately represent the faulted geologic units, which have variable thicknesses and orientations. Irregular grid blocks enable explicit representation of these features. Each hydrogeologic layer is discretized into a single layer of irregular and dipping grid blocks, and faults are discretized such that they are laterally continuous and displacement varies along strike. In addition, the presence of altered fault zones is explicitly modeled, as appropriate. The model has 23 layers and 11 faults, and approximately 57,000 grid blocks and 200,000 grid block connections. In the past, field measurement of upward vertical head gradients and high water table temperatures near faults were interpreted as indicators of upwelling from a deep carbonate aquifer. Simulations show, however, that these features can be readily explained by the geometry of hydrogeologic layers, the variability of layer permeabilities and thermal conductivities, and by the presence of permeable fault zones or faults with displacement only. In addition, a moderate water table gradient can result from fault displacement or a laterally continuous low permeability fault zone, but not from a high permeability fault zone, as others postulated earlier. Large-scale macrodispersion results from the vertical and lateral diversion of flow near the contact of high and low permeability layers at faults, and from upward flow within high permeability fault zones. Conversely, large-scale channeling can occur due to groundwater flow into areas with minimal fault displacement. Contaminants originating at the water table can flow in a direction significantly different than that of the water table gradient, and isolated zones of contaminants will occur at the water table downgradient. This behavior is not predicted by traditional models of contaminant transport. In addition, the influence of a particular type of fault cannot be generalized; depending on the location where contaminants enter the saturated zone, faults may either enhance of inhibit vertical dispersion.
Mohaghegh, Shahab
with a large number of producers, second, to a CO2 sequestration project in Australia, and finally to a numerical simulation study of potential carbon storage site in the United States. The numerical reservoir
Activity Diagrams for DEVS Models: A Case Study Modeling Health Care Behavior
Ozmen, Ozgur [ORNL; Nutaro, James J [ORNL
2015-01-01T23:59:59.000Z
Discrete Event Systems Specification (DEVS) is a widely used formalism for modeling and simulation of discrete and continuous systems. While DEVS provides a sound mathematical representation of discrete systems, its practical use can suffer when models become complex. Five main functions, which construct the core of atomic modules in DEVS, can realize the behaviors that modelers want to represent. The integration of these functions is handled by the simulation routine, however modelers can implement each function in various ways. Therefore, there is a need for graphical representations of complex models to simplify their implementation and facilitate their reproduction. In this work, we illustrate the use of activity diagrams for this purpose in the context of a health care behavior model, which is developed with an agent-based modeling paradigm.
Basic, Ivan [GBS-IT Ltd., CSS Life Science, Prilaz baruna Filipovica 25, 10000 Zagreb (Croatia); Nadramija, Damir [Zagreb Institute of Public Health, Mirogojska 16, Zagreb 10000 (Croatia); Flajslik, Mario [Univesity of Zagreb, Faculty of Electrical Engineering and Computing (Croatia); Amic, Dragan [Josip Juraj Strossmayer University, P. O. Box 719, 31001 Osijek (Croatia); Lucic, Bono [Ruder Boskovic Institute, P. O. Box 180, 10002 Zagreb (Croatia)
2007-12-26T23:59:59.000Z
Several quantitative structure-activity studies for this data set containing 107 HEPT derivatives have been performed since 1997, using the same set of molecules by (more or less) different classes of molecular descriptors. Multivariate Regression (MR) and Artificial Neural Network (ANN) models were developed and in each study the authors concluded that ANN models are superior to MR ones. We re-calculated multivariate regression models for this set of molecules using the same set of descriptors, and compared our results with the previous ones. Two main reasons for overestimation of the quality of the ANN models in previous studies comparing with MR models are: (1) wrong calculation of leave-one-out (LOO) cross-validated (CV) correlation coefficient for MR models in Luco et al., J. Chem. Inf. Comput. Sci. 37 392-401 (1997), and (2) incorrect estimation/interpretation of leave-one-out (LOO) cross-validated and predictive performance and power of ANN models. More precise and fairer comparison of fit and LOO CV statistical parameters shows that MR models are more stable. In addition, MR models are much simpler than ANN ones. For real testing the predictive performance of both classes of models we need more HEPT derivatives, because all ANN models that presented results for external set of molecules used experimental values in optimization of modeling procedure and model parameters.
Luo, Meng
Advanced High Strength Steels (AHSS) are increasingly used in automotive industry due to their superior strength and substantial weight advantage. However, their compromised ductility gives rise to numerous manufacturing ...
Dadi, Sireesh Kumar
2011-10-21T23:59:59.000Z
and both the numerical and the analytical results were compared with a 7-day, constant rate pumping test conducted by University of Waterloo researchers at Canadian Air Force Base Borden in Ontario, Canada....
Theoretical Modeling Issue in Active Noise Control for a One-Dimensional Acoustic Duct System
Yang, Zhenyu
Theoretical Modeling Issue in Active Noise Control for a One-Dimensional Acoustic Duct System-6700 Esbjerg, Denmark Email: yang,sp@aaue.dk Abstract--The theoretical modeling of active noise control for the entire one-dimensional active duct noise control system is obtained and validated. The developed model
Houze, Jr., Robert A. [University of Washington Dept. of Atmospheric Sciences
2013-11-13T23:59:59.000Z
We examined cloud radar data in monsoon climates, using cloud radars at Darwin in the Australian monsoon, on a ship in the Bay of Bengal in the South Asian monsoon, and at Niamey in the West African monsoon. We followed on with a more in-depth study of the continental MCSs over West Africa. We investigated whether the West African anvil clouds connected with squall line MCSs passing over the Niamey ARM site could be simulated in a numerical model by comparing the observed anvil clouds to anvil structures generated by the Weather Research and Forecasting (WRF) mesoscale model at high resolution using six different ice-phase microphysical schemes. We carried out further simulations with a cloud-resolving model forced by sounding network budgets over the Niamey region and over the northern Australian region. We have devoted some of the effort of this project to examining how well satellite data can determine the global breadth of the anvil cloud measurements obtained at the ARM ground sites. We next considered whether satellite data could be objectively analyzed to so that their large global measurement sets can be systematically related to the ARM measurements. Further differences were detailed between the land and ocean MCS anvil clouds by examining the interior structure of the anvils with the satellite-detected the CloudSat Cloud Profiling Radar (CPR). The satellite survey of anvil clouds in the Indo-Pacific region was continued to determine the role of MCSs in producing the cloud pattern associated with the MJO.
Boron-10 ABUNCL Prototype Models And Initial Active Testing
Kouzes, Richard T.; Ely, James H.; Lintereur, Azaree T.; Siciliano, Edward R.
2013-04-23T23:59:59.000Z
The Department of Energy Office of Nuclear Safeguards and Security (NA-241) is supporting the project Coincidence Counting With Boron-Based Alternative Neutron Detection Technology at Pacific Northwest National Laboratory (PNNL) for the development of a 3He proportional counter alternative neutron coincidence counter. The goal of this project is to design, build and demonstrate a system based upon 10B-lined proportional tubes in a configuration typical for 3He-based coincidence counter applications. This report provides results from MCNPX model simulations and initial testing of the active mode variation of the Alternative Boron-Based Uranium Neutron Coincidence Collar (ABUNCL) design built by General Electric Reuter-Stokes. Initial experimental testing of the as-delivered passive ABUNCL was previously reported.
Prickett, T.A.
1980-04-01T23:59:59.000Z
Specifications are given which are necessary to develop a three-dimensional numerical model capable of simulating regional mass transport of radionuclides from a deep waste repository. The model to be developed will include all of the significant mass transport processes including flow, chemical, and thermal advection, mechanical dispersion, molecular diffusion, ion exchange reactions, and radioactive decay. The model specifications also include that density and viscosity fluid properties be functions of pressure, temperature, and concentration and take into account fluid and geologic heterogenieties by allowing possible assignment of individual values to every block of the model. The model specifications furthermore include the repository shape, input/output information, boundary conditions, and the need for documentation and a user's manual. Model code validation can be accomplished with the included known analytical or laboratory solutions. It is recommended that an existing finite-difference model (developed by INTERCOMP and INTERA, Inc.) be used as a starting point either as an acceptable basic code for modification or as a pattern for the development of a completely different numerical scheme. A ten-step plan is given to outline the general procedure for development of the code.
Sokolov, Igor V. [Space Physics Research Laboratory, University of Michigan, Ann Arbor, Michigan 48109 (United States); Naumova, Natalia M. [Laboratoire d'Optique Appliquee, UMR 7639 ENSTA, Ecole Polytechnique, CNRS, 91761 Palaiseau (France); Nees, John A. [Center for Ultrafast Optical Science and FOCUS Center, University of Michigan, Ann Arbor, Michigan 48109 (United States)
2011-09-15T23:59:59.000Z
Ultra-strong laser pulses can be so intense that an electron in the focused beam loses significant energy due to {gamma}-photon emission while its motion deviates via the radiation back-reaction. Numerical methods and tools designed to simulate radiation-dominated and quantum-electrodynamically strong laser-plasma interactions are summarized here.
of formation heterogeneity on convective mixing. Finite volume based numerical code was developed to capture of Canadian Petroleum Technology, 44(10). - Neufeld, J. A., Hesse M. A., Riaz, A., Hallworth M. A., Tchelepi, H. A., and Huppert H. E., 2010, Convective dissolution of carbon dioxide in saline aquifers, Geophys
Kirby, James T.
Palma, Canary Islands): Tsunami source and near field effects S. M. Abadie,1 J. C. Harris,2 S. T. Grilli of the Cumbre Vieja Volcano (CVV; La Palma, Canary Island, Spain) through numerical simulations performed in two of such wave trains on La Palma and other Canary Islands are assessed in detail in the paper. Citation: Abadie
A modified Activated Sludge Model No. 3 (ASM3) with two-step nitrificationedenitrification
A modified Activated Sludge Model No. 3 (ASM3) with two-step nitrificationedenitrification Ilenia of the Activated Sludge Models (ASM) [Henze, M., Gujer, W., Mino, T., van Loosdrecht, M.C.M., 2000. Ac- tivated Sludge Models ASM1, ASM2, ASM2d, and ASM3. IWA Scientific and Technical Report No. 9. IWA Publishing
Current Challenges for Modeling Enzyme Active Sites by Biomimetic Synthetic Diiron Complexes
Friedle, Simone
This tutorial review describes recent progress in modeling the active sites of carboxylate-rich non-heme diiron enzymes that activate dioxygen to carry out several key reactions in Nature. The chemistry of soluble methane ...
Sheng, F.; Wang, K.; Zhang, R.; Liu, H.H.
2009-03-15T23:59:59.000Z
Preferential flow and solute transport are common processes in the unsaturated soil, in which distributions of soil water content and solute concentrations are often characterized as fractal patterns. An active region model (ARM) was recently proposed to describe the preferential flow and transport patterns. In this study, ARM governing equations were derived to model the preferential soil water flow and solute transport processes. To evaluate the ARM equations, dye infiltration experiments were conducted, in which distributions of soil water content and Cl{sup -} concentration were measured. Predicted results using the ARM and the mobile-immobile region model (MIM) were compared with the measured distributions of soil water content and Cl{sup -} concentration. Although both the ARM and the MIM are two-region models, they are fundamental different in terms of treatments of the flow region. The models were evaluated based on the modeling efficiency (ME). The MIM provided relatively poor prediction results of the preferential flow and transport with negative ME values or positive ME values less than 0.4. On the contrary, predicted distributions of soil water content and Cl- concentration using the ARM agreed reasonably well with the experimental data with ME values higher than 0.8. The results indicated that the ARM successfully captured the macroscopic behavior of preferential flow and solute transport in the unsaturated soil.
D'Agnese, F.A.; O'Brien, G.M.; Faunt, C.C.; Belcher, W.R.; San Juan, Carma
2002-11-22T23:59:59.000Z
In the early 1990's, two numerical models of the Death Valley regional ground-water flow system were developed by the U.S. Department of Energy. In general, the two models were based on the same basic hydrogeologic data set. In 1998, the U.S. Department of Energy requested that the U.S. Geological Survey develop and maintain a ground-water flow model of the Death Valley region in support of U.S. Department of Energy programs at the Nevada Test Site. The purpose of developing this ''second-generation'' regional model was to enhance the knowledge and understanding of the ground-water flow system as new information and tools are developed. The U.S. Geological Survey also was encouraged by the U.S. Department of Energy to cooperate to the fullest extent with other Federal, State, and local entities in the region to take advantage of the benefits of their knowledge and expertise. The short-term objective of the Death Valley regional ground-water flow system project was to develop a steady-stat e representation of the predevelopment conditions of the ground-water flow system utilizing the two geologic interpretations used to develop the previous numerical models. The long-term objective of this project was to construct and calibrate a transient model that simulates the ground-water conditions of the study area over the historical record that utilizes a newly interpreted hydrogeologic conceptual model. This report describes the result of the predevelopment steady-state model construction and calibration.
Yu-Shu Wu
2006-02-28T23:59:59.000Z
A three-dimensional site-scale numerical model has been developed to simulate water and gas flow, heat transfer, and radionuclide transport in the unsaturated zone of Yucca Mountain, Nevada, the American underground repository site for high level radioactive waste. The modeling approach is based on a mathematical formulation of coupled multiphase fluid and heat flow and tracer transport through porous and fractured rock. This model is intended for use in predicting current and future conditions in the unsaturated zone, so as to aid in assessing the system performance of the repository. In particular, an integrated modeling methodology is discussed for integrating a wide variety of moisture, pneumatic, thermal, and isotopic geochemical data into comprehensive modeling analyses. The reliability and accuracy of the model predictions were the subject of a comprehensive model calibration study, in which the model was calibrated against measured data, including liquid saturation, water potential, and temperature. This study indicates that the model is able to reproduce the overall system behavior at Yucca Mountain with respect to moisture profiles, pneumatic pressure and chloride concentration variations in different geological units, and ambient geothermal conditions.
ATS 680 A6: Applied Numerical Weather Prediction MW, 1:00-1:50 PM, ACRC Room 212B
, Parameterization Schemes: Keys to Understanding Numerical Weather Prediction Models, Cambridge University Press in class. Numerical model The primary numerical model that will be u
Schuh, Harald
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
Cirpka, Olaf Arie
. It takes into account the two phases CO2 and brine and the components CO2 and water which can dissolve the conceptual model for a non-isothermal composi- tional CO2-water (brine) model based on the simulator MUFTE. MODEL For the description of the flow and transport processes of carbon dioxide and brine in a rock
The Numerical Simulation of Turbulence
W. Schmidt
2007-12-06T23:59:59.000Z
In this contribution, I give an overview of the various approaches toward the numerical modelling of turbulence, particularly, in the interstellar medium. The discussion is placed in a physical context, i. e. computational problems are motivated from basic physical considerations. Presenting selected examples for solutions to these problems, I introduce the basic ideas of the most commonly used numerical methods.
NUMERICAL ANALYSIS KENDALL E. ATKINSON
Atkinson, Kendall
of mathematics and computer science that creates, analyzes, and implements algorithms for solving nu- merically mathematical models in science and engineering, and numerical analysis of increasing sophistication has been of numerical analysis varies from quite theoretical mathematical studies (e.g. see [5]) to computer science
Explorations of iron-iron hydrogenase active site models by experiment and theory
Tye, Jesse Wayne
2009-05-15T23:59:59.000Z
This dissertation describes computational and experimental studies of synthetic complexes that model the active site of the iron-iron hydrogenase [FeFe]H2ase enzyme. Simple dinuclear iron dithiolate complexes act as functional models of the ironiron...
Explorations of iron-iron hydrogenase active site models by experiment and theory
Tye, Jesse Wayne
2009-05-15T23:59:59.000Z
This dissertation describes computational and experimental studies of synthetic complexes that model the active site of the iron-iron hydrogenase [FeFe]H2ase enzyme. Simple dinuclear iron dithiolate complexes act as functional models of the ironiron...
active appearance models: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
and James L. Crowley Olivier.Chomat@inrialpes.fr To be published Computer Vision and Pattern Recognition (CVPR'99) Fort Collins recognition of activities from local...
Buscaglia, Gustavo C.
2012-01-01T23:59:59.000Z
INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING Int. J. Numer. Meth. Biomed iterative coupling of dimen- sionally heterogeneous flow models in computational hemodynamics. INTRODUCTION In recent years, several efforts have been directed at integrating different mathematical models
Pruess editor, K.
2010-01-01T23:59:59.000Z
grid Thermophysical properties of hydrogen Total hydrogen4. Thermophysical properties of hydrogen density at P = 1hydrogen. This is modeled as an ideal gas; the thennophysical properties
Model of Thalamocortical Slow-Wave Sleep Oscillations and Transitions to Activated States
Bazhenov, Maxim
) in nonanesthetized cats, silent (down) states alternate with active (up) states; the down states are absent during of SWS oscillation activated the persistent sodium current and depolarized the membrane of cortical py- ramidal (PY) cells sufficiently for spike generation. In the model, this triggered the active phase, which
Fisher, Andrew
" for20 MAR. Results from the GIS analysis were used with a regional groundwater model to assess the groundwater flowing to the ocean over the long term. Modeling results28 illustrate considerable variability evaluation of options for32 enhancing groundwater resources.33 34 1. Introduction35 Groundwater
Shekhar, Ravi
2009-05-15T23:59:59.000Z
and amplitude variation with offset (AVO) results for our example model predicts that CO2 is easier to detect than brine in the fractured reservoirs. The effects of geochemical processes on seismics are simulated by time-lapse modeling for t = 1000 years. My...
Modeling of a Nickel-Hydrogen Cell Phase Reactions in the Nickel Active Material
Modeling of a Nickel-Hydrogen Cell Phase Reactions in the Nickel Active Material B. Wu and R. E of South Carolina, Columbia, South Carolina 29208, USA A nonisothermal model of a nickel-hydrogen cell has been developed with the consideration of multiple phases in the nickel active material. Important
Modeling - Scale-Bridging Simulations Active Materials in Li...
Broader source: Energy.gov (indexed) [DOE]
Design Using Coupled Kinetic, Thermal and Mechanical Modeling Overview of the Batteries for Advanced Transportation Technologies (BATT) Program Electrochemistry Diagnostics...
activities including modelling: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
nonpoint source models associate pollutant loads almost exclusively agricultural sources: manure, fertilizers, soilplant complexes, and impervious surfaces and those associated...
Class Generation for Numerical Wind Atlases
Class Generation for Numerical Wind Atlases RisÃ¸ National Laboratory Wind Energy Department and The Technical University of Denmark Informatics and Mathematical Modelling Department Nicholas J. Cutler s000144 Constructing a Numerical Wind Atlas 5 2.1 Introduction
Asymptotic Approximations to the Distributed Activation Energy Model
McGuinness, Mark
applicability in situations, such as computational fluid dynamics modelling of coal-fired boilers, where- plex chemical systems such as coal pyrolysis. MRM assumes that the process can be represented Energy Model (DAEM) or multiple reaction model (MRM) for coal pyrolysis [4] may be applied to either
Integrated modeling for design of lightweight, active mirrors
Cohan, Lucy E.
Lightweight, active, silicon carbide mirrors have the potential to enable larger primary aperture, space-based optical systems, hence improving the resolution and sensitivity of such systems. However, due to the lack of ...
Modeling and characterization of potato quality by active thermography
Sun, Chih-Chen
2009-05-15T23:59:59.000Z
This research focuses on characterizing a potato with extra sugar content and identifying the location and depth of the extra sugar content using the active thermography imaging technique. The extra sugar content of the potato is an important...
Modeling and characterization of potato quality by active thermography
Sun, Chih-Chen
2009-05-15T23:59:59.000Z
This research focuses on characterizing a potato with extra sugar content and identifying the location and depth of the extra sugar content using the active thermography imaging technique. The extra sugar content of the ...
Tao, Qingfeng
2010-07-14T23:59:59.000Z
finite difference method to solve the fluid flow in fractures, a fully coupled displacement discontinuity method to build the global relation of fracture deformation, and the Barton-Bandis model of fracture deformation to build the local relation...
Bader, Aaron Craig
2012-01-01T23:59:59.000Z
In this thesis we discuss measurements and modeling of minority heated fast-ion distributions in the Ion Cyclotron Range of Frequencies (ICRF) on the Alcator C-Mod tokamak. Analysis of fast-ions >100Te is important for ...
Numerical modeling of a 2K J-T heat exchanger used in Fermilab Vertical Test Stand VTS-1
Gupta, Prabhat Kumar [Raja Ramanna Centre for Advanced Technology (RRCAT), Indore (MP), India; Rabehl, Roger [FNAL
2014-07-01T23:59:59.000Z
Fermilab Vertical Test Stand-1 (VTS-1) is in operation since 2007 for testing the superconducting RF cavities at 2 K. This test stand has single layer coiled finned tubes heat exchanger before J-T valve. A finite difference based thermal model has been developed in Engineering Equation Solver (EES) to study its thermal performance during filling and refilling to maintain the constant liquid level of test stand. The model is also useful to predict its performance under other various operating conditions and will be useful to design the similar kind of heat exchanger for future needs. Present paper discusses the different operational modes of this heat exchanger and its thermal characteristics under these operational modes. Results of this model have also been compared with the experimental data gathered from the VTS-1 heat exchanger and they are in good agreement with the present model.
active fracture model: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
porosity of naturally fractured reservoirs with no matrix porosity using stochastic fractal models Texas A&M University - TxSpace Summary: Determining fracture characteristics...
active shape modelling: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
including ecology, palaeoecology and forensic science. The model we build represents life cycle and natural variation of both shape and texture over multiple diatom species,...
active shape models: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
including ecology, palaeoecology and forensic science. The model we build represents life cycle and natural variation of both shape and texture over multiple diatom species,...
active shape model: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
including ecology, palaeoecology and forensic science. The model we build represents life cycle and natural variation of both shape and texture over multiple diatom species,...
activity model validation: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
of Panama Canal System Operations Engineering Websites Summary: and modeled in LTSA. Safety and progress requirements are formally expressed as processes that can. It is...
activated sludge model: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
pattern, although some minor discrepancies were observed in the morphology of the 12-lead electrocardiogram. Keywords: Bidomain theory, hybrid model, anisotropy, ventricles,...
active site models: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
pattern, although some minor discrepancies were observed in the morphology of the 12-lead electrocardiogram. Keywords: Bidomain theory, hybrid model, anisotropy, ventricles,...
activity combined models: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
pattern, although some minor discrepancies were observed in the morphology of the 12-lead electrocardiogram. Keywords: Bidomain theory, hybrid model, anisotropy, ventricles,...
active site model: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
pattern, although some minor discrepancies were observed in the morphology of the 12-lead electrocardiogram. Keywords: Bidomain theory, hybrid model, anisotropy, ventricles,...
active aging model: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
pattern, although some minor discrepancies were observed in the morphology of the 12-lead electrocardiogram. Keywords: Bidomain theory, hybrid model, anisotropy, ventricles,...
activated sludge models: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
pattern, although some minor discrepancies were observed in the morphology of the 12-lead electrocardiogram. Keywords: Bidomain theory, hybrid model, anisotropy, ventricles,...
activity indicator model: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
pattern, although some minor discrepancies were observed in the morphology of the 12-lead electrocardiogram. Keywords: Bidomain theory, hybrid model, anisotropy, ventricles,...
active cochlear model: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
pattern, although some minor discrepancies were observed in the morphology of the 12-lead electrocardiogram. Keywords: Bidomain theory, hybrid model, anisotropy, ventricles,...
Lee, C.; Schwab, D. J.; Beletsky, D.; Stroud, J.; Lesht, B.; PNNL; NOAA; Univ. of Michigan; Univ. of Pennsylvania
2007-02-17T23:59:59.000Z
A two-dimensional sediment transport model capable of simulating sediment resuspension of mixed (cohesive plus noncohesive) sediment is developed and applied to quantitatively simulate the March 1998 resuspension events in southern Lake Michigan. Some characteristics of the model are the capability to incorporate several floc size classes, a physically based settling velocity formula, bed armoring, and sediment availability limitation. Important resuspension parameters were estimated from field and laboratory measurement data. The model reproduced the resuspension plume (observed by the SeaWIFS satellite and field instruments) and recently measured sedimentation rate distribution (using radiotracer techniques) fairly well. Model results were verified with field measurements of suspended sediment concentration and settling flux (by ADCPs and sediment traps). Both wave conditions and sediment bed properties (critical shear stress, fine sediment fraction, and limited sediment availability or source) are the critical factors that determine the concentration distribution and width of the resuspension plume. The modeled sedimentation pattern shows preferential accumulation of sediment on the eastern side of the lake, which agrees with the observed sedimentation pattern despite a predominance of particle sources from the western shoreline. The main physical mechanisms determining the sedimentation pattern are (1) the two counter-rotating circulation gyres producing offshore mass transport along the southeastern coast during northerly wind and (2) the settling velocity of sediment flocs which controls the deposition location.
Lee, Cheegwan; Schwab, David J.; Beletsky, Dmitry; Stroud, Jonathan; Lesht, B. M.
2007-02-17T23:59:59.000Z
A two-dimensional sediment transport model capable of simulating sediment resuspension of mixed (cohesive+noncohesive) sediment is developed and applied to quantitatively simulate the March 1998 resuspension events in southern Lake Michigan. Some characteristics of the model are the capability to incorporate several floc size classes, a physically-based settling velocity formula, bed armoring, and sediment availability limitation. Important resuspension parameters were estimated from field and laboratory measurement data. The model reproduced the resuspension plume (observed by the SeaWIFS satellite and field instruments) and recently measured sedimentation rate distribution (using radiotracer techniques) fairly well. Model results were verified with field measurements of suspended sediment concentration and settling flux (by ADCPs and sediment traps). Both wave conditions and sediment bed properties (critical shear stress, fine sediment fraction, and limited sediment availability or source) are the critical factors that determine the concentration distribution and width of the resuspension plume. The modeled sedimentation pattern shows preferential accumulation of sediment on the eastern side of the lake, which agrees with the observed sedimentation pattern despite a predominance of particle sources from the western shoreline. The main physical mechanisms determining the sedimentation pattern are 1) the two counter-rotating circulation gyres producing offshore mass transport along the southeastern coast during northerly wind and 2) the settling velocity of sediment flocs which controls the deposition location.
activation energy model: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
energy model First Page Previous Page 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 Next Page Last Page Topic Index 1 Time-dependent Stochastic Modeling of...
Reliable Computation of Binary Parameters in Activity Coefficient Models
Stadtherr, Mark A.
phase equilibria. The technique is demonstrated with examples using the NRTL and electrolyte-NRTL (eNRTL) models. In two of the NRTL examples, results are found that contradict previous work. In the eNRTL time that a method for parameter estimation in the eNRTL model from binary LLE data (mutual solubility
APPLYING ACTIVITY PATTERNS FOR DEVELOPING AN INTELLIGENT PROCESS MODELING TOOL
Ulm, Universität
attracting the interest of both BPM researchers and BPM tool vendors. Frequently, process models can Process Management (BPM) tools as well as emerging patterns for process modeling and change. BPM processes of an enterprise. Moreover, through Web service technology, the benefits of BPM can be created
Modelling and numerical approximation of a 2.5D set of equations for mesoscale atmospheric processes
Kalise, Dante
2011-01-01T23:59:59.000Z
The set of 3D inviscid primitive equations for the atmosphere is dimensionally reduced by a Discontinuous Galerkin discretization in one horizontal direction. The resulting model is a 2D system of balance laws where with a source term depending on the layering procedure and the choice of coupling fluxes, which is established in terms of upwind considerations. The "2.5D" system is discretized via a WENO-TVD scheme based in a flux limiter centered approach. We study four tests cases related to atmospheric phenomena to analyze the physical validity of the model.
Scott Geraedts; Olexei Motrunich
2014-08-05T23:59:59.000Z
We study a topological phase of interacting bosons in (3+1) dimensions which is protected by charge conservation and time-reversal symmetry. We present an explicit lattice model which realizes this phase and which can be studied in sign-free Monte Carlo simulations. The idea behind our model is to bind bosons to topological defects called hedgehogs. We determine the phase diagram of the model and identify a phase where such bound states are proliferated. In this phase we observe a Witten effect in the bulk whereby an external monopole binds half of the elementary boson charge, which confirms that it is a bosonic topological insulator. We also study the boundary between the topological insulator and a trivial insulator. We find a surface phase diagram which includes exotic superfluids, a topologically ordered phase, and a phase with a Hall effect quantized to one-half of the value possible in a purely two-dimensional system. We also present models that realize symmetry-enriched topologically-ordered phases by binding multiple hedgehogs to each boson; these phases show charge fractionalization and intrinsic topological order as well as a fractional Witten effect.
A Theory of Travel Decision-Making with Applications for Modeling Active Travel Demand
Bertini, Robert L.
A Theory of Travel Decision-Making with Applications for Modeling Active Travel Demand by Patrick methods, the research upon which modeling tools are based has yet to settle on a comprehensive theory, and environmental factors. While modeling tools have explained travel primarily through economic theories
activity coefficient model: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
coefficient and viscosity of popular rigid water models: Two non polarizable ones (SPCE with 3 sites, and TIP4P2005 with 4 sites) and a polarizable one (Dang-Chang, 4...
activity coefficient models: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
coefficient and viscosity of popular rigid water models: Two non polarizable ones (SPCE with 3 sites, and TIP4P2005 with 4 sites) and a polarizable one (Dang-Chang, 4...
Modeling - Scale-Bridging Simulations Active Materials in Li...
Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site
Society, v. 154 (10), pp. A978-A986. 3. Wang, C.-W. and Sastry, A.M., 2007, "Mesoscale Modeling of a Li-Ion Poly Cell," Journal of the Electrochemical Society, v. 154...
Pruess, Karsten; Zhang, Keni
2008-11-17T23:59:59.000Z
For purposes of geologic storage, CO2 would be injected into saline formations at supercritical temperature and pressure conditions, and would form a separate phase that is immiscible with the aqueous phase (brine). At typical subsurface temperature and pressure conditions, supercritical CO2 (scCO2) has lower density than the aqueous phase and would experience an upward buoyancy force. Accordingly, the CO2 is expected to accumulate beneath the caprock at the top of the permeable interval, and could escape from the storage formation wherever (sub-)vertical pathways are available, such as fractures or faults through the caprock, or improperly abandoned wells. Over time, an increasing fraction of CO2 may dissolve in the aqueous phase, and eventually some of the aqueous CO2 may react with rock minerals to form poorly soluble carbonates. Dissolution into the aqueous phase and eventual sequestration as carbonates are highly desirable processes as they would increase permanence and security of storage. Dissolution of CO2 will establish phase equilibrium locally between the overlying CO2 plume and the aqueous phase beneath. If the aqueous phase were immobile, CO2 dissolution would be limited by the rate at which molecular diffusion can remove dissolved CO2 from the interface between CO2-rich and aqueous phases. This is a slow process. However, dissolution of CO2 is accompanied by a small increase in the density of the aqueous phase, creating a negative buoyancy force that can give rise to downward convection of CO2-rich brine, which in turn can greatly accelerate CO2 dissolution. This study explores the process of dissolution-diffusion-convection (DDC), using high-resolution numerical simulation. We find that geometric features of convection patterns are very sensitive to small changes in problem specifications, reflecting self-enhancing feedbacks and the chaotic nature of the process. Total CO2 dissolution rates on the other hand are found to be quite robust against modest changes in problem parameters, and are essentially constant as long as no dissolved CO2 reaches the lower boundary of the system.
Ali, Melkamu; Ye, Sheng; Li, Hongyi; Huang, Maoyi; Leung, Lai-Yung R.; Fiori, Aldo; Sivapalan, Murugesu
2014-07-19T23:59:59.000Z
Subsurface stormflow is an important component of the rainfall-runoff response, especially in steep forested regions. However; its contribution is poorly represented in current generation of land surface hydrological models (LSMs) and catchment-scale rainfall-runoff models. The lack of physical basis of common parameterizations precludes a priori estimation (i.e. without calibration), which is a major drawback for prediction in ungauged basins, or for use in global models. This paper is aimed at deriving physically based parameterizations of the storage-discharge relationship relating to subsurface flow. These parameterizations are derived through a two-step up-scaling procedure: firstly, through simulations with a physically based (Darcian) subsurface flow model for idealized three dimensional rectangular hillslopes, accounting for within-hillslope random heterogeneity of soil hydraulic properties, and secondly, through subsequent up-scaling to the catchment scale by accounting for between-hillslope and within-catchment heterogeneity of topographic features (e.g., slope). These theoretical simulation results produced parameterizations of the storage-discharge relationship in terms of soil hydraulic properties, topographic slope and their heterogeneities, which were consistent with results of previous studies. Yet, regionalization of the resulting storage-discharge relations across 50 actual catchments in eastern United States, and a comparison of the regionalized results with equivalent empirical results obtained on the basis of analysis of observed streamflow recession curves, revealed a systematic inconsistency. It was found that the difference between the theoretical and empirically derived results could be explained, to first order, by climate in the form of climatic aridity index. This suggests a possible codependence of climate, soils, vegetation and topographic properties, and suggests that subsurface flow parameterization needed for ungauged locations must account for both the physics of flow in heterogeneous landscapes, and the co-dependence of soil and topographic properties with climate, including possibly the mediating role of vegetation.
Ghosh, S., E-mail: sabuj.ghosh@saha.ac.in; Kumar Shaw, Pankaj; Sekar Iyengar, A. N.; Janaki, M. S.; Saha, Debajyoti; Michael Wharton, Alpha [Plasma Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India)] [Plasma Physics Division, Saha Institute of Nuclear Physics, 1/AF, Bidhannagar, Kolkata 700064 (India); Mitra, Vramori [Purbasha Housing Estate, Kankurgachi, Kolkata 700054 (India)] [Purbasha Housing Estate, Kankurgachi, Kolkata 700054 (India)
2014-03-15T23:59:59.000Z
Intermittent chaos was observed in a glow discharge plasma as the system evolved from regular type of relaxation oscillations (of larger amplitude) to an irregular type of oscillations (of smaller amplitude) as the discharge voltage was increased. Floating potential fluctuations were analyzed by different statistical and spectral methods. Features like a gradual change in the normal variance of the interpeak time intervals, a dip in the skewness, and a hump in the kurtosis with variation in the control parameter have been seen, which are strongly indicative of intermittent behavior in the system. Detailed analysis also suggests that the intrinsic noise level in the experiment increases with the increasing discharge voltage. An attempt has been made to model the experimental observations by a second order nonlinear ordinary differential equation derived from the fluid equations for an unmagnetized plasma. Though the experiment had no external forcing, it was conjectured that the intrinsic noise in the experiment could be playing a vital role in the dynamics of the system. Hence, a constant bias and noise as forcing terms were included in the model. Results from the theoretical model are in close qualitative agreement with the experimental results.
Victoria-Rueda, Carlos Humberto
1981-01-01T23:59:59.000Z
). The amount of organic carbon yield by the leaves of Thalassia compares well, and in many cases surpasses, average values reported for tropical rain forest and reef ecosystems and intensively cultivated agroecosystems such as hybrid corn, rice... course of my graduate studies. I extend my grat1tude to Dr, Rezneat Darnell, co-chairman of the committee, who initiated my interest in the top1c of ecosystem modeling. His constructive crit1cism and contr1bution to this work is fully appreciated. I...
Hebenstreit, Gerald Thomas
1974-01-01T23:59:59.000Z
surface with no allowance for exchange induced by wave action. The model does produce reasonable solutions, in comparison with oceanic data, for the response of the lower atmosphere and the upper ocean to specific. sets of meteorological and oceanic.../2 this function is of the form f(Ri) = (1 + b Ri) , then one obtains ? 3 1/2 2 -1 K (z) = K 62 (gX ) exp(z/W) (z/I + rdI) (1 + b Ri) hw 1 (61) Although KITAIGORODSKII (1961) does not give a specific value of b, it would appear that b = 10/3 would be in line...
Lim, M. A.
A growing body of research indicates that amyotrophic lateral sclerosis (ALS) patients and mouse models of ALS exhibit metabolic dysfunction. A subpopulation of ALS patients possesses higher levels of resting energy ...
Pal, Sujay
2015-01-01T23:59:59.000Z
In this thesis, we theoretically predict the normal characteristics of Very Low Frequency (3~30 kHz) radio wave propagation through Earth-ionosphere waveguide corresponding to normal behavior of the D-region ionosphere. We took the VLF narrow band data from the receivers of Indian Centre for Space Physics (ICSP) to validate our models. Detection of sudden ionospheric disturbances (SIDs) are common to all the measurements. We apply our theoretical models to infer the D-region characteristics and to reproduce the observed VLF signal behavior corresponding to such SIDs. We develop a code based on ray theory to simulate the diurnal behavior of VLF signals over short propagation paths (2000~3000 km). The diurnal variation from this code are comparable to the variation obtained from a more general Long Wave Propagation Capability (LWPC) code which is based on mode theory approach. We simulate the observational results obtained during the Total Solar Eclipse of July 22, 2009 in India. We also report and simulate a h...
Active Shape Models & Segmentation of the Left Ventricle in Echocardiography
Paragios, Nikos
NATIONALE DES PONTS ET CHAUSSEES, Champs sur Marne, France 2 Imaging and Visualization Department, SIEMENS transformation that projects this model to the desired image fea- tures. During the second step, a linear segmentation Research was carried out during the affiliation of the author with Siemens Corporate Research from
Using Active Deformable Models in Robotic Visual Servoing
of Minnesota 4-192 EE/CS Building 200 Union Street SE Minneapolis, MN 55455 September 9, 1997 Submitted to the book \\Event-Based Sensing, Planning and Control of a Robotic System: An Integrated Approach" #12 are updated at frame rates by minimizing an energy function involving the relative position of model points
Graphical Models for Wide-Area Activity Analysis in Continuous Videos
Nayak, Nandita Miyar
2014-01-01T23:59:59.000Z
2 Multi-person Activity Recognition in Wide-area Videos 2.1Context Modeling in Continuous Videos Using Graphical Modelsmethod. Given a continuous video with computed tracklets, a
Yang, L.H.; Ding, Y.M. [China University of Mining & Technology, Xuzhou (China). College of Resources and Geoscience
2009-07-01T23:59:59.000Z
The aim of this article is to discuss the distribution law of the gasification agent concentration in a deep-going way during underground coal gasification and the new method of solving the problem for the convection diffusion of the gas. In this paper, the basic features of convection diffusion for the gas produced in underground coal gasification are studied. On the basis of the model experiment, through the analysis of the distribution and patterns of variation for the fluid concentration field in the process of the combustion and gasification of the coal seams within the gasifier, the 3-D non-linear unstable mathematical models on the convection diffusion for oxygen are established. In order to curb such pseudo-physical effects as numerical oscillation and surfeit which frequently occurred in the solution of the complex mathematical models, the novel finite unit algorithm, the upstream weighted multi-cell balance method is advanced in this article, and its main derivation process is introduced.
A mathematical model for countercurrent moving-bed activated carbon adsorption
Anderson, Douglas Harold
1976-01-01T23:59:59.000Z
the column. There was insufficient data taken to verify this model. The testing procedure was limited by the approximate uniformity of the influent concentrations in the pilot plant and the effect of the activated carbon concentration and initial solute...A MATHEMATICAL MODEL FOR COUNTERCURRENT MOVING-BED ACTIVATED CARBON ADSORPTION A Thesis by DOUGLAS HAROLD ANDERSON Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER...
Giurgiutiu, Victor
Structural health monitoring with piezoelectric wafer active sensors predictive modeling of the state of the art in structural health monitoring with piezoelectric wafer active sensors and follows with conclusions and suggestions for further work Key Words: structural health monitoring, SHM, nondestructive
Organometallic Complexes that Model the Active Sites of the [FeFe]- and [Fe]-Hydrogenases
Liu, Tianbiao
2011-02-22T23:59:59.000Z
My research primarily focuses on biomimetics of the active sites of the [FeFe]- and [Fe]-hydrogenases (H2ase) and is classified into three parts. Part A: The one-electron oxidation of asymmetrically disubstituted FeIFeI models of the active site...
A Model of OASIS Role-Based Access Control and its Support for Active Security
Cambridge, University of
A Model of OASIS Role-Based Access Control and its Support for Active Security Walt Yao University.bacon@cl.cam.ac.uk ABSTRACT OASIS is a role-based access control architecture for achiev- ing secure interoperation rule associated with its activation becomes false. OASIS does not use role delegation but instead
A Model of OASIS RoleBased Access Control and its Support for Active Security
Cambridge, University of
A Model of OASIS RoleBased Access Control and its Support for Active Security Walt Yao University.bacon@cl.cam.ac.uk ABSTRACT OASIS is a role-based access control architecture for achiev- ing secure interoperation rule associated with its activation becomes false. OASIS does not use role delegation but instead de#12
Giurgiutiu, Victor
chart show the trends in the power and energy flow behavior with remarkable peaks and valleys that can1 Modeling of Power and Energy Transduction of Embedded Piezoelectric Wafer Active Sensors a systematic investigation of power and energy transduction in piezoelectric wafer active sensors (PWAS
An Active Oscillator Model Describes the Statistics of Spontaneous Otoacoustic Emissions
Juelicher, Frank
Article An Active Oscillator Model Describes the Statistics of Spontaneous Otoacoustic Emissions, sounds that are known as spontaneous otoacoustic emissions. They are a signature of the active amplification mechanism in the cochlea. Emissions occur at frequencies that are unique for an individual
Organometallic Complexes that Model the Active Sites of the [FeFe]- and [Fe]-Hydrogenases
Liu, Tianbiao
2011-02-22T23:59:59.000Z
My research primarily focuses on biomimetics of the active sites of the [FeFe]- and [Fe]-hydrogenases (H2ase) and is classified into three parts. Part A: The one-electron oxidation of asymmetrically disubstituted FeIFeI models of the active site...
Rockhold, Mark L.; Bacon, Diana H.; Freedman, Vicky L.; Lindberg, Michael J.; Clayton, Ray E.
2012-03-19T23:59:59.000Z
To characterize the extent of contamination under the 324 Building, a pit was excavated on the north side of the building in 2010 by Washington Closure Hanford LLC (WCH). Horizontal closed-end steel access pipes were installed under the foundation of the building from this pit and were used for measuring temperatures and exposure rates under the B-Cell. The deployed sensors measured elevated temperatures of up to 61 C (142 F) and exposure rates of up to 8,900 R/hr. WCH suspended deactivation of the facility because it recognized that building safety systems and additional characterization data might be needed for remediation of the contaminated material. The characterization work included additional field sampling, laboratory measurements, and numerical flow and transport modeling. Laboratory measurements of sediment physical, hydraulic, and geochemical properties were performed by Pacific Northwest National Laboratory (PNNL) and others. Geochemical modeling and subsurface flow and transport modeling also were performed by PNNL to evaluate the possible extent of contamination in the unsaturated sand and gravel sediments underlying the building. Historical records suggest that the concentrated 137Cs- and 90Sr-bearing liquid wastes that were spilled in B-Cell were likely from a glass-waste repository testing program associated with the Federal Republic of Germany (FRG). Incomplete estimates of the aqueous chemical composition (no anion data provided) of the FRG waste solutions were entered into a geochemical speciation model and were charge balanced with nitrate to estimate waste composition. Additional geochemical modeling was performed to evaluate reactions of the waste stream with the concrete foundation of the building prior to the stream entering the subsurface.
Bonnefous, Y.C. [Ecole Nationale des Travaux Publics de l`Etat, 69 - Vaulx en Velin (France). Lab. Sciences de l`Habitat]|[Lawrence Berkeley Lab., CA (United States); Gadgil, A.J. [Lawrence Berkeley Lab., CA (United States); Allard, F. [Institut National des Sciences Appliquees (INSA), 69 - Villeurbanne (France)
1992-04-01T23:59:59.000Z
The functioning of an active sub-slab ventilation system (SVS) has been studied successfully with the help of a previously evaluated numerical model. The parameters explored are the permeability of the sub-slab and the gravel placed beneath it, the amplitude of applied pressure at the installation point of the system and the functioning method: depressurization or pressurization. The mechanisms contributing to the success of the two systems are identified. This numerical study shows that the presence of a layer of gravel beneath the sub-slab considerably improves the performance of the SVS. Considered separately from the extremely permeable sub-slabs, the depressurization systems perform better than the pressurization systems. 17 refs. [Francais] Le fonctionnement des Systemes de Ventilation active du Sol (SVS) a ete etudie a l`aide d`un outil numerique precedemment evalue avec succes. Les parametres explores sont les permeabilites du sol et du gravier place sous plancher bas, l`amplitude de la pression appliquee au point d`installation du systeme, et le mode de fonctionnement: Depressurisation ou Pressurisation. Les mecanismes contribuant au succes des deux systemes sont identifies. Cette etude numerique montre que la presence d`une couche de gravier sous plancher bas ameliore de facon considerable les performances des SVS. Mis a part le cas des sols extremement permeables, les systemes de Depressurisation ont de meilleures performances que les systemes de Pressurisation. 17 refs.
MUSCLE ACTIVITY DETECTION FROM MYOELECTRIC SIGNALS BASED ON THE AR-GARCH MODEL
Bouaynaya, Nidhal
MUSCLE ACTIVITY DETECTION FROM MYOELECTRIC SIGNALS BASED ON THE AR-GARCH MODEL Ghulam Rasool Heteroscedastic (AR-GARCH) process, which captures the heteroscedasticity of the signal. The Akaike information cri- terion test confirms that the AR-GARCH model better fits the EMG signal than the stationary AR
Modeling and Visualization of Human Activities for Multi-Camera Networks
Sankaranarayanan, Aswin C.
of the scene. These are used to render the scene with virtual 3D human models that mimic the observed instant are then presented to a rendering engine that animates a set of virtual actors synthesizing1 Modeling and Visualization of Human Activities for Multi-Camera Networks Aswin C
Grid Cells: The Position Code, Neural Network Models of Activity, and the Problem of Learning
Fiete, Ila
COMMENTARY Grid Cells: The Position Code, Neural Network Models of Activity, and the Problem on the modeling and theoretical fronts in the quest to unravel the computational properties of the grid cell code and to explain the mechanisms underlying grid cell dynamics. The goals of the review are to outline a coherent
A. S. Rood
2010-10-01T23:59:59.000Z
This report describes the Mixing Cell Model code, a one-dimensional model for water flow and solute transport in the unsaturated zone under steady-state or transient flow conditions. The model is based on the principles and assumptions underlying mixing cell model formulations. The unsaturated zone is discretized into a series of independent mixing cells. Each cell may have unique hydrologic, lithologic, and sorptive properties. Ordinary differential equations describe the material (water and solute) balance within each cell. Water flow equations are derived from the continuity equation assuming that unit-gradient conditions exist at all times in each cell. Pressure gradients are considered implicitly through model discretization. Unsaturated hydraulic conductivity and moisture contents are determined by the material-specific moisture characteristic curves. Solute transport processes include explicit treatment of advective processes, first-order chain decay, and linear sorption reactions. Dispersion is addressed through implicit and explicit dispersion. Implicit dispersion is an inherent feature of all mixing cell models and originates from the formulation of the problem in terms of mass balance around fully mixed volume elements. Expressions are provided that relate implicit dispersion to the physical dispersion of the system. Two FORTRAN codes were developed to solve the water flow and solute transport equations: (1) the Mixing-Cell Model for Flow (MCMF) solves transient water flow problems and (2) the Mixing Cell Model for Transport (MCMT) solves the solute transport problem. The transient water flow problem is typically solved first by estimating the water flux through each cell in the model domain as a function of time using the MCMF code. These data are stored in either ASCII or binary files that are later read by the solute transport code (MCMT). Code output includes solute pore water concentrations, water and solute inventories in each cell and at each specified output time, and water and solute fluxes through each cell and specified output time. Computer run times for coupled transient water flow and solute transport were typically several seconds on a 2 GHz Intel Pentium IV desktop computer. The model was benchmarked against analytical solutions and finite-element approximations to the partial differential equations (PDE) describing unsaturated flow and transport. Differences between the maximum solute flux estimated by the mixing-cell model and the PDE models were typically less than two percent.
Movshovitz, Naor; Asphaug, Erik; Korycansky, Donald, E-mail: nmovshov@ucsc.edu [Department of Earth and Planetary Sciences, University of California, Santa Cruz, 1156 High Street, Santa Cruz, CA 95064 (United States)
2012-11-10T23:59:59.000Z
We advance the modeling of rubble-pile solid bodies by re-examining the tidal breakup of comet Shoemaker-Levy 9, an event that occurred during a 1.33 R encounter with Jupiter in 1992 July. Tidal disruption of the comet nucleus led to a chain of sub-nuclei {approx}100-1000 m diameter; these went on to collide with the planet two years later. They were intensively studied prior to and during the collisions, making SL9 the best natural benchmark for physical models of small-body disruption. For the first time in the study of this event, we use numerical codes treating rubble piles as collections of polyhedra. This introduces forces of dilatation and friction, and inelastic response. As in our previous studies we conclude that the progenitor must have been a rubble pile, and we obtain approximately the same pre-breakup diameter ({approx}1.5 km) in our best fits to the data. We find that the inclusion of realistic fragment shapes leads to grain locking and dilatancy, so that even in the absence of friction or other dissipation we find that disruption is overall more difficult than in our spheres-based simulations. We constrain the comet's bulk density at {rho}{sub bulk} {approx} 300-400 kg m{sup -3}, half that of our spheres-based predictions and consistent with recent estimates derived from spacecraft observations.
Technosocial Modeling for Determining the Status and Nature of a State’s Nuclear Activities
Gastelum, Zoe N.; Harvey, Julia B.
2009-09-25T23:59:59.000Z
The International Atomic Energy Agency State Evaluation Process: The Role of Information Analysis in Reaching Safeguards Conclusions (Mathews et al. 2008), several examples of nonproliferation models using analytical software were developed that may assist the IAEA with collecting, visualizing, analyzing, and reporting information in support of the State Evaluation Process. This paper focuses on one of the examples a set of models developed in the Proactive Scenario Production, Evidence Collection, and Testing (ProSPECT) software that evaluates the status and nature of a state’s nuclear activities. The models use three distinct subject areas to perform this assessment: the presence of nuclear activities, the consistency of those nuclear activities with national nuclear energy goals, and the geopolitical context in which those nuclear activities are taking place. As a proof-of-concept for the models, a crude case study was performed. The study, which attempted to evaluate the nuclear activities taking place in Syria prior to September 2007, yielded illustrative, yet inconclusive, results. Due to the inconclusive nature of the case study results, changes that may improve the model’s efficiency and accuracy are proposed.
Active patterning and asymmetric transport in a model actomyosin network
Shenshen Wang; Peter G. Wolynes
2014-12-19T23:59:59.000Z
Cytoskeletal networks, which are essentially motor-filament assemblies, play a major role in many developmental processes involving structural remodeling and shape changes. These are achieved by nonequilibrium self-organization processes that generate functional patterns and drive intracellular transport. We construct a minimal physical model that incorporates the coupling between nonlinear elastic responses of individual filaments and force-dependent motor action. By performing stochastic simulations we show that the interplay of motor processes, described as driving anti-correlated motion of the network vertices, and the network connectivity, which determines the percolation character of the structure, can indeed capture the dynamical and structural cooperativity which gives rise to diverse patterns observed experimentally. The buckling instability of individual filaments is found to play a key role in localizing collapse events due to local force imbalance. Motor-driven buckling-induced node aggregation provides a dynamic mechanism that stabilizes the two dimensional patterns below the apparent static percolation limit. Coordinated motor action is also shown to suppress random thermal noise on large time scales, the two dimensional configuration that the system starts with thus remaining planar during the structural development. By carrying out similar simulations on a three dimensional anchored network, we find that the myosin-driven isotropic contraction of a well-connected actin network, when combined with mechanical anchoring that confers directionality to the collective motion, may represent a novel mechanism of intracellular transport, as revealed by chromosome translocation in the starfish oocyte.
Geometric Numerical Methods for Numerical Weather Prediction
Langdon, Stephen
-Mesh (HPM) Method · Label space is discretised into N particles with coordinates on the momentum phase space and Sij = (1 - ^2xx)-1. Geometric Numerical Methods for Numerical Weather Prediction p. 8/28 #12;HPM Equations of shallow water motions · The canonical HPM equations of 1D shallow water motion on TS1 are P
Numerical Modeling | Open Energy Information
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, searchOfRoseConcerns Jumpsource HistoryFractures below a Borehole Floor, A Jump
Cengarle, MarÃa Victoria
to real automotive subsystems. These difficulties include complexity and methodological issues, and what in the respective engineering domain. Automotive industry has become one of the major areas in which model, failure-modes-and- effects analysis (FMEA), and diagnosability analysis, we decided to explore
Activity of the kinesin spindle protein inhibitor ispinesib (SB-715992) in models of breast cancer
Purcell, James W; Davis, Jefferson; Reddy, Mamatha; Martin, Shamra; Samayoa, Kimberly; Vo, Hung; Thomsen, Karen; Bean, Peter; Kuo, Wen Lin; Ziyad, Safiyyah; Billig, Jessica; Feiler, Heidi S; Gray, Joe W; Wood, Kenneth W; Cases, Sylvaine
2009-06-10T23:59:59.000Z
Ispinesib (SB-715992) is a potent inhibitor of kinesin spindle protein (KSP), a kinesin motor protein essential for the formation of a bipolar mitotic spindle and cell cycle progression through mitosis. Clinical studies of ispinesib have demonstrated a 9% response rate in patients with locally advanced or metastatic breast cancer, and a favorable safety profile without significant neurotoxicities, gastrointestinal toxicities or hair loss. To better understand the potential of ispinesib in the treatment of breast cancer we explored the activity of ispinesib alone and in combination several therapies approved for the treatment of breast cancer. We measured the ispinesib sensitivity and pharmacodynamic response of breast cancer cell lines representative of various subtypes in vitro and as xenografts in vivo, and tested the ability of ispinesib to enhance the anti-tumor activity of approved therapies. In vitro, ispinesib displayed broad anti-proliferative activity against a panel of 53 breast cell-lines. In vivo, ispinesib produced regressions in each of five breast cancer models, and tumor free survivors in three of these models. The effects of ispinesib treatment on pharmacodynamic markers of mitosis and apoptosis were examined in vitro and in vivo, revealing a greater increase in both mitotic and apoptotic markers in the MDA-MB-468 model than in the less sensitive BT-474 model. In vivo, ispinesib enhanced the anti-tumor activity of trastuzumab, lapatinib, doxorubicin, and capecitabine, and exhibited activity comparable to paclitaxel and ixabepilone. These findings support further clinical exploration of KSP inhibitors for the treatment of breast cancer.
Eindhoven, Technische Universiteit
Numerical Simulation of PulseTube Refrigerators: 1D model I.A. Lyulina 1 , R.M.M. Mattheij 1 , A of a pulsetube refrigerator. Conservation equations describing compressible gas flow in the tube are solved, calculate the average enthalpy flow and estimate the refrigeration power. Keywords: pulsetube refrigerator
Wu, Weibin [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China) [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Institutes of Biomedical Science, Fudan University, Shanghai 200032 (China); Zhu, Bo; Peng, Xiaomin [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China)] [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Zhou, Meiling, E-mail: meilingzhou2012@gmail.com [Department of Radiology, Zhongshan Hospital of Fudan University and Shanghai Institute of Medical Imaging, Shanghai 200032 (China)] [Department of Radiology, Zhongshan Hospital of Fudan University and Shanghai Institute of Medical Imaging, Shanghai 200032 (China); Jia, Dongwei, E-mail: jiadongwei@fudan.edu.cn [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China)] [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Gu, Jianxin [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China) [Department of Biochemistry and Molecular Biology, Shanghai Medical College, Fudan University, Shanghai 200032 (China); Institutes of Biomedical Science, Fudan University, Shanghai 200032 (China)
2014-01-03T23:59:59.000Z
Highlights: •FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. •Activation of FXR attenuated alcohol-induced liver injury and steatosis. •Activation of FXR attenuated cholestasis and oxidative stress in mouse liver. -- Abstract: Alcoholic liver disease (ALD) is a common cause of advanced liver disease, and considered as a major risk factor of morbidity and mortality worldwide. Hepatic cholestasis is a pathophysiological feature observed in all stages of ALD. The farnesoid X receptor (FXR) is a member of the nuclear hormone receptor superfamily, and plays an essential role in the regulation of bile acid, lipid and glucose homeostasis. However, the role of FXR in the pathogenesis and progression of ALD remains largely unknown. Mice were fed Lieber-DeCarli ethanol diet or an isocaloric control diet. We used a specific agonist of FXR WAY-362450 to study the effect of pharmacological activation of FXR in alcoholic liver disease. In this study, we demonstrated that FXR activity was impaired by chronic ethanol ingestion in a murine model of ALD. Activation of FXR by specific agonist WAY-362450 protected mice from the development of ALD. We also found that WAY-362450 treatment rescued FXR activity, suppressed ethanol-induced Cyp2e1 up-regulation and attenuated oxidative stress in liver. Our results highlight a key role of FXR in the modulation of ALD development, and propose specific FXR agonists for the treatment of ALD patients.
Hoffman, Forrest M [ORNL; Randerson, James T [ORNL; Thornton, Peter E [ORNL; Bonan, Gordon [National Center for Atmospheric Research (NCAR); Erickson III, David J [ORNL; Fung, Inez [University of California, Berkeley
2009-12-01T23:59:59.000Z
The need to capture important climate feedbacks in general circulation models (GCMs) has resulted in efforts to include atmospheric chemistry and land and ocean biogeochemistry into the next generation of production climate models, called Earth System Models (ESMs). While many terrestrial and ocean carbon models have been coupled to GCMs, recent work has shown that such models can yield a wide range of results (Friedlingstein et al., 2006). This work suggests that a more rigorous set of global offline and partially coupled experiments, along with detailed analyses of processes and comparisons with measurements, are needed. The Carbon-Land Model Intercomparison Project (C-LAMP) was designed to meet this need by providing a simulation protocol and model performance metrics based upon comparisons against best-available satellite- and ground-based measurements (Hoffman et al., 2007). Recently, a similar effort in Europe, called the International Land Model Benchmark (ILAMB) Project, was begun to assess the performance of European land surface models. These two projects will now serve as prototypes for a proposed international land-biosphere model benchmarking activity for those models participating in the IPCC Fifth Assessment Report (AR5). Initially used for model validation for terrestrial biogeochemistry models in the NCAR Community Land Model (CLM), C-LAMP incorporates a simulation protocol for both offline and partially coupled simulations using a prescribed historical trajectory of atmospheric CO2 concentrations. Models are confronted with data through comparisons against AmeriFlux site measurements, MODIS satellite observations, NOAA Globalview flask records, TRANSCOM inversions, and Free Air CO2 Enrichment (FACE) site measurements. Both sets of experiments have been performed using two different terrestrial biogeochemistry modules coupled to the CLM version 3 in the Community Climate System Model version 3 (CCSM3): the CASA model of Fung, et al., and the carbon-nitrogen (CN) model of Thornton. Comparisons of the CLM3 offline results against observational datasets have been performed and are described in Randerson et al. (2009). CLM version 4 has been evaluated using C-LAMP, showing improvement in many of the metrics. Efforts are now underway to initiate a Nitrogen-Land Model Intercomparison Project (N-LAMP) to better constrain the effects of the nitrogen cycle in biosphere models. Presented will be new results from C-LAMP for CLM4, initial N-LAMP developments, and the proposed land-biosphere model benchmarking activity.
Numerical uncertainty in computational engineering and physics
Hemez, Francois M [Los Alamos National Laboratory
2009-01-01T23:59:59.000Z
Obtaining a solution that approximates ordinary or partial differential equations on a computational mesh or grid does not necessarily mean that the solution is accurate or even 'correct'. Unfortunately assessing the quality of discrete solutions by questioning the role played by spatial and temporal discretizations generally comes as a distant third to test-analysis comparison and model calibration. This publication is contributed to raise awareness of the fact that discrete solutions introduce numerical uncertainty. This uncertainty may, in some cases, overwhelm in complexity and magnitude other sources of uncertainty that include experimental variability, parametric uncertainty and modeling assumptions. The concepts of consistency, convergence and truncation error are overviewed to explain the articulation between the exact solution of continuous equations, the solution of modified equations and discrete solutions computed by a code. The current state-of-the-practice of code and solution verification activities is discussed. An example in the discipline of hydro-dynamics illustrates the significant effect that meshing can have on the quality of code predictions. A simple method is proposed to derive bounds of solution uncertainty in cases where the exact solution of the continuous equations, or its modified equations, is unknown. It is argued that numerical uncertainty originating from mesh discretization should always be quantified and accounted for in the overall uncertainty 'budget' that supports decision-making for applications in computational physics and engineering.
Numerical simulation of hydraulic fracturing
Warner, Joseph Barnes
1987-01-01T23:59:59.000Z
~ared that the results of such treatments were not always adequately described by the two-dimensional models. With recent advances in hydraulic fracturing and computing technology, attempts have been made to formulate more realistic fracture models. These three...NUMERICAL SIMULATION OF HYDRAULIC FRACTURING A Thesis by JOSEPH BARNES WARNER Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1987 Maj or Subj ect...
Friedle, Simone, 1976-
2009-01-01T23:59:59.000Z
Chapter 1. Different Synthetic Approaches to Modeling the Active Sites of Carboxylate-Bridged Non-Heme Diiron Enzymes Carboxylate-bridged non-heme diiron enzymes activate dioxygen to perform a variety of biological functions. ...
Hands-On and Minds-On Modeling Activities to Improve Students' Conceptions of Microscopic Friction
Zollman, Dean
Hands-On and Minds-On Modeling Activities to Improve Students' Conceptions of Microscopic Friction of microscopic friction. We will also present our investigation on the relative effectiveness of the use, it is possible to facilitate the refinement of students' ideas of microscopic friction. Keywords: friction
Giurgiutiu, Victor
damage assessment, and are considered as a new non-destructive evaluation method. The in-situ impedance of experimental results obtained from previous work. The real part of the measured PWAS impedance presents twoOn the Modeling of Piezoelectric Wafer Active Sensor Impedance Analysis for Structural Health
MODELLING RADIATIVELY ACTIVE WATER-ICE CLOUDS: IMPACT ON THE THERMAL STRUCTURE AND WATER CYCLE.
Madeleine, Jean-Baptiste
MODELLING RADIATIVELY ACTIVE WATER-ICE CLOUDS: IMPACT ON THE THERMAL STRUCTURE AND WATER CYCLE. J. The essential role of water-ice clouds in shaping the thermal structure of the martian atmosphere has been long presumed [1] but neglected in GCMs because of the lack of observations and difficulty to predict
A Model for the Interfacial Kinetics of Phospholipase D Activity on Long-Chain Lipids
Mayer, Michael
-water interfaces and is an example of heterogeneous catalysis in biology. Recently we showed that planar lipid for inter- facial catalysis that includes product activation and substrate depletion. This model describes on the structure and properties of these interfaces (1). The underlying variables that govern catalysis
Paris-Sud XI, Université de
effects on osteo- blast activity in the canine rib and (2) this effect depends on whether modeling reduce bone loss in part through direct actions on osteoclasts. Their effects on osteoblasts and bone treatments (+108 to +175%, P effect on MAR at either the en- docortical
Undefined 21-4 (2010) 1 1 Towards Automated Models of Activities of
Cremers, Daniel
2010-01-01T23:59:59.000Z
Beetz , Moritz Tenorth, Dominik Jain, and Jan Bandouch Intelligent Autonomous Systems Group, Technische in- formative models of human activities enables ma- *Corresponding Author: Michael Beetz Intelligent-85748 Garching. E-mail: beetz@cs.tum.edu *Corresponding Author: Michael Beetz Intelligent Autonomous
CONTROL OF AN IDEAL ACTIVATED SLUDGE PROCESS IN WASTEWATER TREATMENT VIA AN ODE-PDE MODEL
Diehl, Stefan
CONTROL OF AN IDEAL ACTIVATED SLUDGE PROCESS IN WASTEWATER TREATMENT VIA AN ODE-PDE MODEL STEFAN treatment plants, consists basically of a biological reactor followed by a sedi- mentation tank, which has. 1. Introduction The need for efficient wastewater treatment plants in terms of low effluent con
Frost Growth CFD Model of an Integrated Active Desiccant Rooftop Unit
Geoghegan, Patrick J [ORNL; Petrov, Andrei Y [ORNL; Vineyard, Edward Allan [ORNL; Zaltash, Abdolreza [ORNL; Linkous, Randall Lee [ORNL
2008-01-01T23:59:59.000Z
A frost growth model is incorporated into a Computational Fluid Dynamics (CFD) simulation of a heat pump by means of a user-defined function in FLUENT, a commercial CFD code. The transient model is applied to the outdoor section of an Integrated Active Desiccant Rooftop (IADR) unit in heating mode. IADR is a hybrid vapor compression and active desiccant unit capable of handling 100% outdoor air (dedicated outdoor air system) or as a total conditioning system, handling both outdoor air and space cooling or heating loads. The predicted increase in flow resistance and loss in heat transfer capacity due to frost build-up are compared to experimental pressure drop readings and thermal imaging. The purpose of this work is to develop a CFD model that is capable of predicting frost growth, an invaluable tool in evaluating the effectiveness of defrost-on-demand cycles.
SOLAR MAGNETIC ACTIVITY CYCLES, CORONAL POTENTIAL FIELD MODELS AND ERUPTION RATES
Petrie, G. J. D. [National Solar Observatory, Tucson, AZ 85719 (United States)
2013-05-10T23:59:59.000Z
We study the evolution of the observed photospheric magnetic field and the modeled global coronal magnetic field during the past 3 1/2 solar activity cycles observed since the mid-1970s. We use synoptic magnetograms and extrapolated potential-field models based on longitudinal full-disk photospheric magnetograms from the National Solar Observatory's three magnetographs at Kitt Peak, the Synoptic Optical Long-term Investigations of the Sun vector spectro-magnetograph, the spectro-magnetograph and the 512-channel magnetograph instruments, and from Stanford University's Wilcox Solar Observatory. The associated multipole field components are used to study the dominant length scales and symmetries of the coronal field. Polar field changes are found to be well correlated with active fields over most of the period studied, except between 2003 and 2006 when the active fields did not produce significant polar field changes. Of the axisymmetric multipoles, only the dipole and octupole follow the poles whereas the higher orders follow the activity cycle. All non-axisymmetric multipole strengths are well correlated with the activity cycle. The tilt of the solar dipole is therefore almost entirely due to active-region fields. The axial dipole and octupole are the largest contributors to the global field except while the polar fields are reversing. This influence of the polar fields extends to modulating eruption rates. According to the Computer Aided CME Tracking, Solar Eruptive Event Detection System, and Nobeyama radioheliograph prominence eruption catalogs, the rate of solar eruptions is found to be systematically higher for active years between 2003 and 2012 than for those between 1997 and 2002. This behavior appears to be connected with the weakness of the late-cycle 23 polar fields as suggested by Luhmann. We see evidence that the process of cycle 24 field reversal is well advanced at both poles.
2005-10-20T23:59:59.000Z
Page 1. LAB #8. Numerical Methods. Goal: The purpose of this lab is to explain how computers numerically ... Also you will examine what .... (7) Now consider the differential equation ... 3-exp(2*y)+sqrt(t)/y; (Don't forget the “;” at the end.).
Saeed, Noha M. [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Egyptian Russian University, Cairo (Egypt)] [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Egyptian Russian University, Cairo (Egypt); El-Demerdash, Ebtehal [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo (Egypt)] [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo (Egypt); Abdel-Rahman, Hanaa M. [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Egyptian Russian University, Cairo (Egypt)] [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Egyptian Russian University, Cairo (Egypt); Algandaby, Mardi M. [Department of Biology (Botany), Faculty of Science, King Abdulaziz University, Jeddah (Saudi Arabia)] [Department of Biology (Botany), Faculty of Science, King Abdulaziz University, Jeddah (Saudi Arabia); Al-Abbasi, Fahad A. [Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah (Saudi Arabia)] [Department of Biochemistry, Faculty of Science, King Abdulaziz University, Jeddah (Saudi Arabia); Abdel-Naim, Ashraf B., E-mail: abnaim@pharma.asu.edu.eg [Department of Pharmacology and Toxicology, Faculty of Pharmacy, Ain Shams University, Cairo (Egypt)
2012-10-01T23:59:59.000Z
Methyl palmitate (MP) and ethyl palmitate (EP) are naturally occurring fatty acid esters reported as inflammatory cell inhibitors. In the current study, the potential anti-inflammatory activity of MP and EP was evaluated in different experimental rat models. Results showed that MP and EP caused reduction of carrageenan-induced rat paw edema in addition to diminishing prostaglandin E2 (PGE2) level in the inflammatory exudates. In lipopolysaccharide (LPS)-induced endotoxemia in rats, MP and EP reduced plasma levels of tumor necrosis factor-? (TNF-?) and interleukin-6 (IL-6). MP and EP decreased NF-?B expression in liver and lung tissues and ameliorated histopathological changes caused by LPS. Topical application of MP and EP reduced ear edema induced by croton oil in rats. In the same animal model, MP and EP reduced neutrophil infiltration, as indicated by decreased myeloperoxidase (MPO) activity. In conclusion, this study demonstrates the effectiveness of MP and EP in combating inflammation in several experimental models. -- Highlights: ? Efficacy of MP and EP in combating inflammation was displayed in several models. ? MP and EP reduced carrageenan-induced rat paw edema and prostaglandin E2 level. ? MP and EP decreased TNF-? and IL-6 levels in experimental endotoxemia. ? MP and EP reduced NF-?B expression and histological changes in rat liver and lung. ? MP and EP reduced croton oil-induced ear edema and neutrophil infiltration.
Numerical modeling of injection and mineral trapping of CO2 withH2S and SO2 in a Sandstone Formation
Xu, Tianfu; Apps, John A.; Pruess, Karsten; Yamamoto, Hajime
2004-09-07T23:59:59.000Z
Carbon dioxide (CO{sub 2}) injection into deep geologic formations could decrease the atmospheric accumulation of this gas from anthropogenic sources. Furthermore, by co-injecting H{sub 2}S or SO{sub 2}, the products respectively of coal gasification or combustion, with captured CO{sub 2}, problems associated with surface disposal would be mitigated. We developed models that simulate the co-injection of H{sub 2}S or SO{sub 2} with CO{sub 2} into an arkose formation at a depth of about 2 km and 75 C. The hydrogeology and mineralogy of the injected formation are typical of those encountered in Gulf Coast aquifers of the United States. Six numerical simulations of a simplified 1-D radial region surrounding the injection well were performed. The injection of CO{sub 2} alone or co-injection with SO{sub 2} or H{sub 2}S results in a concentrically zoned distribution of secondary minerals surrounding a leached and acidified region adjacent to the injection well. Co-injection of SO{sub 2} with CO{sub 2} results in a larger and more strongly acidified zone, and alteration differs substantially from that caused by the co-injection of H{sub 2}S or injection of CO{sub 2} alone. Precipitation of carbonates occurs within a higher pH (pH > 5) peripheral zone. Significant quantities of CO{sub 2} are sequestered by ankerite, dawsonite, and lesser siderite. The CO{sub 2} mineral-trapping capacity of the formation can attain 40-50 kg/m{sup 3} medium for the selected arkose. In contrast, secondary sulfates precipitate at lower pH (pH < 5) within the acidified zone. Most of the injected SO{sub 2} is transformed and immobilized through alunite precipitation with lesser amounts of anhydrite and minor quantities of pyrite. The dissolved CO{sub 2} increases with time (enhanced solubility trapping). The mineral alteration induced by injection of CO{sub 2} with either SO{sub 2} or H{sub 2}S leads to corresponding changes in porosity. Significant increases in porosity occur in the acidified zones where mineral dissolution dominates. With co-injection of SO{sub 2}, the porosity increases from an initial 0.3 to 0.43 after 100 years. However, within the CO{sub 2} mineral-trapping zone, the porosity decreases to about 0.28 for both cases, because of the addition of CO{sub 2} mass as secondary carbonates to the rock matrix. Precipitation of sulfates at the acidification front causes porosity to decrease to 0.23. The limited information currently available on the mineralogy of naturally occurring high-pressure CO{sub 2} reservoirs is generally consistent with our simulations.
Model-driven multi-omic data analysis elucidates metabolic immunomodulators of macrophage activation
Bordbar, Aarash; Mo, Monica L.; Nakayasu, Ernesto S.; Rutledge, Alexandra C.; Kim, Young-Mo; Metz, Thomas O.; Jones, Marcus B.; Frank, Bryan C.; Smith, Richard D.; Peterson, Scott N.; Hyduke, Daniel R.; Adkins, Joshua N.; Palsson, Bernhard O.
2012-06-26T23:59:59.000Z
Macrophages are central players in the immune response, manifesting divergent phenotypes to control inflammation and innate immunity through the release of cytokines and other regulatory factor-dependent signaling pathways. In recent years, the focus on metabolism has been reemphasized as critical signaling and regulatory pathways of human pathophysiology, ranging from cancer to aging, often converge on metabolic responses. Here, we used genome-scale modeling and multi-omics (transcriptomics, proteomics, and metabolomics) analysis to assess metabolic features critical for macrophage functions. We constructed a genome-scale metabolic network for the RAW 264.7 cell line to determine metabolic modulators of macrophage activation. Metabolites well-known to be associated with immunoactivation (e.g., glucose and arginine) and immunosuppression (e.g., tryptophan and vitamin D3) were amongst the most critical effectors. Intracellular metabolic mechanisms linked to critical suppressive effectors were then assessed, identifying a suppressive role for de novo nucleotide synthesis. Finally, the underlying metabolic mechanisms of macrophage activation are identified by analyzing multi-omic data obtained from LPS-stimulated RAW cells in the context of our flux-based predictions. Our study demonstrates metabolism's role in regulating activation may be greater than previously anticipated and elucidates underlying metabolic connections between activation and metabolic effectors.
Numerical Analysis Gordon K. Smyth
Smyth, Gordon K.
Numerical Analysis Gordon K. Smyth May 1997 Numerical analysis is concerned with the accurate discipline of numerÂ ical analysis is almost entirely a product of the period since 1950 during which biostatisticians can benefit from familiarity with numerical analysis. An understanding of the numerical methods
Oxidation of substrates tethered to N-donor ligands for modeling non-heme diiron enzyme active sites
Carson, Emily Carrig, 1978-
2005-01-01T23:59:59.000Z
Chapter 1. Modeling Carboxylate-Rich Diiron Sites of Dioxygen-Dependent Non-Heme Enzymes Carboxylate-bridged diiron centers are employed in a variety of biological systems to activate dioxygen for substrate oxidation, and ...
Magnetic properties of a diferrous-water complex and ligands for modeling the active site of MMOH
Kelly, Amy E. (Amy Elizabeth), 1980-
2004-01-01T23:59:59.000Z
Chapter 1: The Importance of Modeling Diiron Sites in Nature.There are a variety of metalloenzymes that have nearly identical carboxylate-bridged diiron active sites. An example is sMMOH, an enzyme that catalyzes the ...
Li, Yang
A novel triptycene-based ligand with a preorganized framework was designed to model carboxylate-bridged diiron active sites in bacterial multicomponent monooxygenase (BMM) hydroxylase enzymes. The synthesis of the ...
Cremers, Daniel
Towards Automated Models of Activities of Daily Life Michael Beetz, Jan Bandouch, Dominik Jain and Moritz Tenorth Intelligent Autonomous Systems, Technische Universit¨at M¨unchen {beetz, bandouch, jain
Wactlar, Howard D.
on blobs and trajectories output from this tracking system. In Zelnik-Manor and Irani (2001), dynamicArticulated Motion Modeling for Activity Analysis Jiang Gao, Robert T. Collins, Alexander G at a nursing home. 1. Introduction Much recent research has been focused on activity analysis in videos
Modelling the effects of solar activity onto the Greek national electric grid
Zois, Ioannis P
2013-01-01T23:59:59.000Z
We study both the short term and long term effects of solar activity on the large transformers (150kV and 400kV) of the Greek national electric grid. We use data analysis and various analytic and statistical methods and models. Contrary to the common belief in PPC Greece, we see that there are considerable both short term (immediate) and long term effects of solar activity onto large transformers in a mid-latitude country like Greece. Our results can be summarized as follows: For the short term effects: During 1989-2010 there were 43 stormy days (namely days with for example Ap larger or equal to 100) and we had 19 failures occurring during a stormy day plus or minus 3 days and 51 failures occurring during a stormy day plus or minus 7 days. All these failures can be directly related to Geomagnetically Induced Currents (GICs). Explicit cases are presented. For the long term effects we have two main results: The maximum number of transformer failures occur 3-4 years after the maximum of solar activity. There is...
A nanoflare model for active region radiance: application of artificial neural networks
M. Bazarghan; H. Safari; D. E. Innes; E. Karami; S. K. Solanki
2008-12-20T23:59:59.000Z
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.
Threedimensional numerical simulation for various geometries
Herbin, Raphaèle
modelling and numerical simulation of natural gasfed solid oxide cells (Solid Oxide Fuel Cell, SOFC) at a stationary regime. The principle of a Solid Oxide Fuel Cell (SOFC) is based on the conversion of the chemical is taken into account in the present model. The SOFC systems seem to be of great interest for use
Subtask 2.2 - Creating A Numerical Technique for Microseismic Data Inversion
Anastasia Dobroskok; Yevhen Holubnyak; James Sorensen
2009-05-01T23:59:59.000Z
Geomechanical and geophysical monitoring are the techniques which can complement each other and provide enhancement in the solutions of many problems of geotechnical engineering. One of the most promising geophysical techniques is passive seismic monitoring. The essence of the technique is recording the acoustic signals produced in the subsurface, either naturally or in response to human activity. The acoustic signals are produced by mechanical displacements on the contacts of structural elements (e.g., faults, boundaries of rock blocks, natural and induced fractures). The process can be modeled by modern numerical techniques developed in geomechanics. The report discusses a study that was aimed at the unification of the passive seismic monitoring and numerical modeling for the monitoring of the hydraulic fracture propagation. The approach adopted in the study consisted of numerical modeling of the seismicity accompanying hydraulic fracture propagation and defining seismic attributes and patterns characterizing the process and fracture parameters. Numerical experiments indicated that the spatial distribution of seismic events is correlated to geometrical parameters of hydrofracture. Namely, the highest density of the events is observed along fracture contour, and projection of the events to the fracture plane makes this effect most pronounced. The numerical experiments also showed that dividing the totality of the events into groups corresponding to the steps of fracture propagation allows for reconstructing the geometry of the resulting fracture more accurately than has been done in the majority of commercial applications.
Disruptive Innovation in Numerical Hydrodynamics
Waltz, Jacob I. [Los Alamos National Laboratory
2012-09-06T23:59:59.000Z
We propose the research and development of a high-fidelity hydrodynamic algorithm for tetrahedral meshes that will lead to a disruptive innovation in the numerical modeling of Laboratory problems. Our proposed innovation has the potential to reduce turnaround time by orders of magnitude relative to Advanced Simulation and Computing (ASC) codes; reduce simulation setup costs by millions of dollars per year; and effectively leverage Graphics Processing Unit (GPU) and future Exascale computing hardware. If successful, this work will lead to a dramatic leap forward in the Laboratory's quest for a predictive simulation capability.
Xu, Tianfu; Apps, John A.; Pruess, Karsten; Yamamoto, Hajime
2008-01-01T23:59:59.000Z
Australia. Am. Assoc. Petrol. Geol. Bull. 76(8), 1224-1249.modeling. Mineral. and Petrol. 59, 121-140. Gunter, W.D. ,
Gupta, A.; Moridis, G.J.; Kneafsey, T.J.; Sloan, Jr., E.D.
2009-08-15T23:59:59.000Z
The numerical simulator TOUGH+HYDRATE (T+H) was used to predict the transient pure methane hydrate (no sediment) dissociation data. X-ray computed tomography (CT) was used to visualize the methane hydrate formation and dissociation processes. A methane hydrate sample was formed from granular ice in a cylindrical vessel, and slow depressurization combined with thermal stimulation was applied to dissociate the hydrate sample. CT images showed that the water produced from the hydrate dissociation accumulated at the bottom of the vessel and increased the hydrate dissociation rate there. CT images were obtained during hydrate dissociation to confirm the radial dissociation of the hydrate sample. This radial dissociation process has implications for dissociation of hydrates in pipelines, suggesting lower dissociation times than for longitudinal dissociation. These observations were also confirmed by the numerical simulator predictions, which were in good agreement with the measured thermal data during hydrate dissociation. System pressure and sample temperature measured at the sample center followed the CH{sub 4} hydrate L{sub w}+H+V equilibrium line during hydrate dissociation. The predicted cumulative methane gas production was within 5% of the measured data. Thus, this study validated our simulation approach and assumptions, which include stationary pure methane hydrate-skeleton, equilibrium hydrate-dissociation and heat- and mass-transfer in predicting hydrate dissociation in the absence of sediments. It should be noted that the application of T+H for the pure methane hydrate system (no sediment) is outside the general applicability limits of T+H.
Rzepa, Henry S.
I2S2 Idealised Scientific Research Activity Lifecycle Model The model represents the processes include: development of the research proposal; its peer-review; carrying out of the experiment; equipment configuration and calibration data; processing software and associated control parameters; wikis
Pelanti, Marica
, cavitation and evaporation waves Marica Pelantia, , Keh-Ming Shyueb aDepartment of Mechanical Engineering, Taiwan. Abstract We model liquid-gas flows with cavitation by a variant of the six-equation single cavitation mechanisms and evaporation wave dynamics. Keywords: multiphase compressible flow models
Pohlmann Karl,Ye Ming
2012-03-01T23:59:59.000Z
Models of groundwater flow for the Yucca Flat area of the Nevada National Security Site (NNSS) are under development by the U.S. Department of Energy (DOE) for corrective action investigations of the Yucca Flat-Climax Mine Corrective Action Unit (CAU). One important aspect of these models is the quantity of inter-basin groundwater flow from regional systems to the north. This component of flow, together with its uncertainty, must be properly accounted for in the CAU flow models to provide a defensible regional framework for calculations of radionuclide transport that will support determinations of the Yucca Flat-Climax Mine contaminant boundary. Because characterizing flow boundary conditions in northern Yucca Flat requires evaluation to a higher level of detail than the scale of the Yucca Flat-Climax Mine CAU model can efficiently provide, a study more focused on this aspect of the model was required.
Laible, Allyson Marie
2009-05-15T23:59:59.000Z
that fluorescence increases up to 24 hours after an initial delay of approximately four hours. The fluorescence data was also used to develop a model describing significant events leading to NF-?B activation and GFP expression. In addition, a model describing...
Kansas, University of
Applications of Artificial Neural Networks and Fuzzy Models in High Throughput Screening to the existing HTS method, via Quantitative Structure-Activity Relationship (QSAR) using Artificial Neural in solving non-linear pattern classification problems, we propose several different models of neural networks
Numerical Integration Gordon K. Smyth
Smyth, Gordon K.
Numerical Integration Gordon K. Smyth in Encyclopedia of Biostatistics (ISBN 0471 975761) Edited by Peter Armitage and Theodore Colton John Wiley & Sons, Ltd, Chichester, 1998 #12;Numerical Integration Numerical integration is the study of how the numerical value of an integral can be found. Also called
MODELING SUPER-FAST MAGNETOSONIC WAVES OBSERVED BY SDO IN ACTIVE REGION FUNNELS
Ofman, L. [Department of Physics, Catholic University of America, Washington, DC 20064 (United States); Liu, W.; Title, A.; Aschwanden, M. [Lockheed Martin Solar and Astrophysics Laboratory, Palo Alto, CA 94304 (United States)
2011-10-20T23:59:59.000Z
Recently, quasi-periodic, rapidly propagating waves have been observed in extreme ultraviolet by the Solar Dynamics Observatory/Atmospheric Imaging Assembly (AIA) instrument in about 10 flare/coronal mass ejection (CME) events thus far. A typical example is the 2010 August 1 C3.2 flare/CME event that exhibited arc-shaped wave trains propagating in an active region (AR) magnetic funnel with {approx}5% intensity variations at speeds in the range of 1000-2000 km s{sup -1}. The fast temporal cadence and high sensitivity of AIA enabled the detection of these waves. We identify them as fast magnetosonic waves driven quasi-periodically at the base of the flaring region and develop a three-dimensional MHD model of the event. For the initial state we utilize the dipole magnetic field to model the AR and include gravitationally stratified density at coronal temperature. At the coronal base of the AR, we excite the fast magnetosonic wave by periodic velocity pulsations in the photospheric plane confined to a funnel of magnetic field lines. The excited fast magnetosonic waves have similar amplitude, wavelength, and propagation speeds as the observed wave trains. Based on the simulation results, we discuss the possible excitation mechanism of the waves, their dynamical properties, and the use of the observations for coronal MHD seismology.
A direct comparison of X-ray spectral models for tori in active galactic nuclei
Liu, Yuan
2015-01-01T23:59:59.000Z
Several X-ray spectral models for tori in active galactic nuclei (AGNs) are available to constrain the properties of tori; however, the accuracy of these models has not been verified. We recently construct a code for the torus using Geant4, which can easily handle different geometries (Liu & Li 2014). Thus, we adopt the same assumptions as Murphy & Yaqoob (2009, hereafter MY09) and Brightman & Nandra (2011, hereafter BN11) and try to reproduce their spectra. As a result, we can reproduce well the reflection spectra and the strength of the Fe K$\\alpha$ line of MY09, for both $\\NH=10^{24}$ and $10^{25}$ cm$^{-2}$. However, we cannot produce the strong reflection component of BN11 in the low-energy band. The origin of this component is the reflection from the visible inner wall of the torus, and it should be very weak in the edge-on directions under the geometry of BN11. Therefore, the behaviour of the reflection spectra in BN11 is not consistent with their geometry. The strength of the Fe K$\\alpha$ ...
Prowell, I.; Robertson, A.; Jonkman, J.; Stewart, G. M.; Goupee, A. J.
2013-01-01T23:59:59.000Z
Realizing the critical importance the role physical experimental tests play in understanding the dynamics of floating offshore wind turbines, the DeepCwind consortium conducted a one-fiftieth-scale model test program where several floating wind platforms were subjected to a variety of wind and wave loading condition at the Maritime Research Institute Netherlands wave basin. This paper describes the observed behavior of a tension-leg platform, one of three platforms tested, and the systematic effort to predict the measured response with the FAST simulation tool using a model primarily based on consensus geometric and mass properties of the test specimen.
G. Litak; M. Wendeker; M. Krupa; J. Czarnigowski
2004-05-23T23:59:59.000Z
We examine a simple, fuel-air, model of combustion in a spark ignition (si) engine with indirect injection. In our two fluid model, variations of fuel mass burned in cycle sequences appear due to stochastic fluctuations of a fuel feed amount. We have shown that a small amplitude of these fluctuations affects considerably the stability of a combustion process strongly depending on the quality of air-fuel mixture. The largest influence was found in the limit of a lean combustion. The possible effect of nonlinearities in the combustion process has been also discussed.
Eric M. Leonard; Mitchell A. Plummer; Paul E. Carrara
2014-04-01T23:59:59.000Z
Well-preserved moraines from the penultimate, or Bull Lake, glaciation of Snowmass Creek Valley in the Elk Range of Colorado present an opportunity to examine the character of the high-altitude climate in the Rocky Mountains during Marine Oxygen Isotope Stage 6. This study employs a 2-D coupled mass/energy balance and flow model to assess the magnitudes of temperature and precipitation change that could have sustained the glacier in mass-balance equilibrium at its maximum extent during the Bull Lake glaciation. Variable substrate effects on glacier flow and ice thickness make the modeling somewhat more complex than in geologically simpler settings. Model results indicate that a temperature depression of about 6.7°C compared with the present (1971–2000 AD) would have been necessary to sustain the Snowmass Creek glacier in mass-balance equilibrium during the Bull Lake glaciation, assuming no change in precipitation amount or seasonality. A 50% increase or decrease from modern precipitation would have been coupled with 5.2°C and 9.1°C Bull Lake temperature depressions respectively. Uncertainty in these modeled temperature depressions is about 1°C.
Bonèa, Janez
, such as the self-consistent Born approximation SCBA ,26 self- consistent perturbational approach SCPA ,5 the Green's function, defined in imaginary time. The SCBA and SCPA calculations are likewise limited results8,9,18 are not necessarily compa- rable with SCBA, SCPA, and ED results of the t-J model
Mohaghegh, Shahab
) or using the simplest production data analysis approach( e.g. Decline curve analysis) by knowing the fact of Petroleum Engineers and are subject to correction by the author(s). The material does not necessarily modeling is to strike a balance between explicit representation of reservoir complexity and long simulation
Herbin, RaphaÃ¨le
. Therefore, any modeling attempt of this zone should use reactive transport codes taking into account (ANDRA) and the French Electricity Producer (EDF) are jointly developing the software platform Alliances [24, 27]. This offers the possibility of designing coupling algorithms for reactive transport
Mironova, Irina A.
Â¨a Geophysical Observatory, University of Oulu, Finland 2 Ioffe Physical-Technical Institute, St provided the energy spectrum of incoming cosmic rays is known. It computes the background ionization due this a new model we evaluate the ionization effects in the atmosphere caused by several major solar energetic
Casado, J M
2015-01-01T23:59:59.000Z
Rhythms in electrical activity in the membrane of cells in the suprachiasmatic nucleus (SCN) are crucial for the function of the circadian timing system, which is characterized by the expression of the so-called clock genes. Intracellular Ca$^{2+}$ ions seem to connect, at least in part, the electrical activity of SCN neurons with the expression of clock genes. In this paper, we introduce a simple mathematical model describing the linking of membrane activity to the transcription of one gene by means of a feedback mechanism based on the dynamics of intracellular calcium ions.
Numerical Simulations of Thermobaric Explosions
Kuhl, A L; Bell, J B; Beckner, V E; Khasainov, B
2007-05-04T23:59:59.000Z
A Model of the energy evolution in thermobaric explosions is presented. It is based on the two-phase formulation: conservation laws for the gas and particle phases along with inter-phase interaction terms. It incorporates a Combustion Model based on the mass conservation laws for fuel, air and products; source/sink terms are treated in the fast-chemistry limit appropriate for such gas dynamic fields. The Model takes into account both the afterburning of the detonation products of the booster with air, and the combustion of the fuel (Al or TNT detonation products) with air. Numerical simulations were performed for 1.5-g thermobaric explosions in five different chambers (volumes ranging from 6.6 to 40 liters and length-to-diameter ratios from 1 to 12.5). Computed pressure waveforms were very similar to measured waveforms in all cases - thereby proving that the Model correctly predicts the energy evolution in such explosions. The computed global fuel consumption {mu}(t) behaved as an exponential life function. Its derivative {dot {mu}}(t) represents the global rate of fuel consumption. It depends on the rate of turbulent mixing which controls the rate of energy release in thermobaric explosions.
Sergei Rybalko; Ekaterina Zhuchkova
2006-03-15T23:59:59.000Z
We propose a quite general model of active media by consideration of the interaction between pacemakers via their phase response curves. This model describes a network of pulse oscillators coupled by their response to the internal depolarization of mutual stimulations. First, a macroscopic level corresponding to an arbitrary large number of oscillatory elements coupled globally is considered. As a specific and important case of the proposed model, the bidirectional interaction of two cardiac nodes is described. This case is generalized by means of an additional pacemaker, which can be expounded as an external stimulater. The behavior of such a system is analyzed. Second, the microscopic level corresponding to the representation of cardiac nodes by one-- and two--dimensional lattices of pulse oscillators coupled via the nearest neighbors is described. The model is a universal one in the sense that on its basis one can easily construct discrete distributed media of active elements, which interact via phase response curves.
Numerical Valuation of Discrete Barrier Options with
Chu, Hao-hua
Numerical Valuation of Discrete Barrier Options with the Adaptive Mesh Model and Other Competing for discrete barrier options such that many methods have been suggested and declared to price discrete barrier options fast and accurately but no one can tell exactly that what method is the best. We also make
Model-based Analysis of HER Activation in Cells Co-Expressing EGFR, HER2 and HER3.
Shankaran, Harish; Zhang, Yi; Tan, Yunbing; Resat, Haluk
2013-08-22T23:59:59.000Z
The HER/ErbB family of receptor tyrosine kinases drive critical responses in normal physiology and cancer, and the expression levels of the various HER receptors are critical determinants of clinical outcomes. HER activation is driven by the formation of various dimer complexes between members of this receptor family. The HER dimer types can have differential effects on downstream signaling and phenotypic outcomes. We constructed an integrated mathematical model of HER activation and trafficking to quantitatively link receptor expression levels to dimerization and activation. We parameterized the model with a comprehensive set of HER phosphorylation and abundance data collected in a panel of human mammary epithelial cells expressing varying levels of EGFR, HER2 and HER3. Although parameter estimation yielded multiple solutions, predictions for dimer phosphorylation were in agreement with each other. We validated the model using experiments where pertuzumab was used to block HER2 dimerization. We used the model to predict HER dimerization and activation patterns in a panel of epithelial cells lines with known HER expression levels. Simulations over the range of expression levels seen in various cell lines indicate that: i) EGFR phosphorylation is driven by HER1/1 and HER1/2 dimers, and not HER1/3 dimers, ii) HER1/2 and HER2/3 dimers both contribute significantly to HER2 activation with the EGFR expression level determining the relative importance of these species, and iii) the HER2/3 dimer is largely responsible for HER3 activation. The model can be used to predict phosphorylated dimer levels for any given HER expression profile. This information in turn can be used to quantify the potencies of the various HER dimers, and can potentially inform personalized therapeutic approaches.
Commons-oriented information syntheses : a model for user-driven design and creation activities
Sukkasi, Sittha
2008-01-01T23:59:59.000Z
The phenomenon of user-driven creation activities has recently emerged and is quickly expanding, especially on the Web. A growing number of people participate in online activities, where they generate content by themselves, ...
Numerical Integration Gordon K. Smyth
Smyth, Gordon K.
Numerical Integration Gordon K. Smyth May 1997 Numerical integration is the study of how the numerical value of an integral can be found. Also called quadrature, which refers to finding a square whose \\Lambda . Of central interest is the process of approximating a definite integral from values of the in
Numerical Analysis Gordon K. Smyth
Smyth, Gordon K.
Numerical Analysis Gordon K. Smyth in Encyclopedia of Biostatistics (ISBN 0471 975761) Edited by Peter Armitage and Theodore Colton John Wiley & Sons, Ltd, Chichester, 1998 #12;Numerical Analysis Numerical analysis is concerned with the accurate and efficient evalua- tion of mathematical expressions
Dynamical Spacetimes from Numerical Hydrodynamics
Allan Adams; Nathan Benjamin; Arvin Moghaddam; Wojciech Musial
2014-11-07T23:59:59.000Z
We numerically construct dynamical asymptotically-AdS$_4$ metrics by evaluating the fluid/gravity metric on numerical solutions of dissipative hydrodynamics in (2+1) dimensions. The resulting numerical metrics satisfy Einstein's equations in (3+1) dimensions to high accuracy.
Wisconsin at Madison, University of
This is a 1D model of an active magnetic regenerative refrigerator (AMRR) that was developed of an Active Magnetic Regenerator Refrigerator 1. Governing Equations Figure 1 shows a schematic of an active in MATLAB. The model uses cycle inputs such as the fluid mass flow and magnetic field profiles, fluid
Winebarger, Amy R. [NASA Marshall Space Flight Center, VP 62, Huntsville, AL 35812 (United States); Schmelz, Joan T. [Physics Department, University of Memphis, Memphis, TN 38152 (United States); Warren, Harry P. [Space Science Division, Naval Research Laboratory, Washington, DC 20375 (United States); Saar, Steve H.; Kashyap, Vinay L., E-mail: amy.r.winebarger@nasa.gov [Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138 (United States)
2011-10-10T23:59:59.000Z
The frequency of heating events in the corona is an important constraint on the coronal heating mechanisms. Observations indicate that the intensities and velocities measured in active region cores are effectively steady, suggesting that heating events occur rapidly enough to keep high-temperature active region loops close to equilibrium. In this paper, we couple observations of active region (AR) 10955 made with the X-Ray Telescope and the EUV Imaging Spectrometer on board Hinode to test a simple steady heating model. First we calculate the differential emission measure (DEM) of the apex region of the loops in the active region core. We find the DEM to be broad and peaked around 3 MK. We then determine the densities in the corresponding footpoint regions. Using potential field extrapolations to approximate the loop lengths and the density-sensitive line ratios to infer the magnitude of the heating, we build a steady heating model for the active region core and find that we can match the general properties of the observed DEM for the temperature range of 6.3 < log T < 6.7. This model, for the first time, accounts for the base pressure, loop length, and distribution of apex temperatures of the core loops. We find that the density-sensitive spectral line intensities and the bulk of the hot emission in the active region core are consistent with steady heating. We also find, however, that the steady heating model cannot address the emission observed at lower temperatures. This emission may be due to foreground or background structures, or may indicate that the heating in the core is more complicated. Different heating scenarios must be tested to determine if they have the same level of agreement.
Status of NINJA: the Numerical INJection Analysis project
Benjamin Aylott; John G. Baker; William D. Boggs; Michael Boyle; Patrick R. Brady; Duncan A. Brown; Bernd Brügmann; Luisa T. Buchman; Alessandra Buonanno; Laura Cadonati; Jordan Camp; Manuela Campanelli; Joan Centrella; Shourov Chatterjis; Nelson Christensen; Tony Chu; Peter Diener; Nils Dorband; Zachariah B. Etienne; Joshua Faber; Stephen Fairhurst; Benjamin Farr; Sebastian Fischetti; Gianluca Guidi; Lisa M. Goggin; Mark Hannam; Frank Herrmann; Ian Hinder; Sascha Husa; Vicky Kalogera; Drew Keppel; Lawrence E. Kidder; Bernard J. Kelly; Badri Krishnan; Pablo Laguna; Carlos O. Lousto; Ilya Mandel; Pedro Marronetti; Richard Matzner; Sean T. McWilliams; Keith D. Matthews; R. Adam Mercer; Satyanarayan R. P. Mohapatra; Abdul H. Mroué; Hiroyuki Nakano; Evan Ochsner; Yi Pan; Larne Pekowsky; Harald P. Pfeiffer; Denis Pollney; Frans Pretorius; Vivien Raymond; Christian Reisswig; Luciano Rezzolla; Oliver Rinne; Craig Robinson; Christian Röver; Lucía Santamaría; Bangalore Sathyaprakash; Mark A. Scheel; Erik Schnetter; Jennifer Seiler; Stuart L. Shapiro; Deirdre Shoemaker; Ulrich Sperhake; Alexander Stroeer; Riccardo Sturani; Wolfgang Tichy; Yuk Tung Liu; Marc van der Sluys; James R. van Meter; Ruslan Vaulin; Alberto Vecchio; John Veitch; Andrea Viceré; John T. Whelan; Yosef Zlochower
2009-05-26T23:59:59.000Z
The 2008 NRDA conference introduced the Numerical INJection Analysis project (NINJA), a new collaborative effort between the numerical relativity community and the data analysis community. NINJA focuses on modeling and searching for gravitational wave signatures from the coalescence of binary system of compact objects. We review the scope of this collaboration and the components of the first NINJA project, where numerical relativity groups shared waveforms and data analysis teams applied various techniques to detect them when embedded in colored Gaussian noise.
Puntambekar, Shweta
2009-01-01T23:59:59.000Z
nitric oxide synthase ITAM: immunoreceptor tyrosine basedbased activation motif (ITAM). The TLTs, have longermotif (ITIM). S S S S (DAP-12) ITAM ITIM Charged amino acid
A Numerical Investigation of Wettability Alteration during Immiscible CO2
Hossain, M. Enamul
A Numerical Investigation of Wettability Alteration during Immiscible CO2 Flooding Process, April 2012 #12;2 Table of Contest Abstract 3 Introduction 3 Literature Review 5 CO2 Flooding 7 New alteration during CO2 flooding. However, limited research on numerical and/or analytical modeling
CSU ATS703 Fall 2012 Numerical Weather Prediction
CSU ATS703 Fall 2012 Numerical Weather Prediction ATS703 is based on the course notes and papers method. A crucial element of accurate weather prediction is initialization, which is briefly discussed in Chapter 11. In the next decade, numerical weather prediction will expe- rience a revolution in model
Numerical Simulation of a Natural Circulation Steam Generator
WeinmÃ¼ller, Ewa B.
Numerical Simulation of a Natural Circulation Steam Generator W. Linzer \\Lambda , K. Ponweiser circulation steam generator. We focus on a model with a simple geometry consisting of two vertical pipes properties of water and steam. We present a numerical algorithm based on an explicit upwind discretization
Modeling of Power and Energy Transduction of Embedded Piezoelectric Wafer Active Sensors for
Giurgiutiu, Victor
Transmitter INPUT Transmitter PWAS A'A Electrical response (7-mm transmitter) Â Active power Â Reactive power Â Reactive power is dominant Â· capacitive behavior 0 200 400 600 0 1000 2000 3000 4000 Electrical Reactive Power frequency (kHz) Power(mW) 21 ^ 2 active RP Y V 21 ^ 2 reactive IP Y V Piezoelectric transduction
Motion Pattern Analysis for Modeling and Recognition of Complex Human Activities
Chowdhury, Amit K. Roy
, research in activity recognition is moving towards more complex scenes involving multiple objects-mail: amitrc@ee.ucr.edu 1 This work has been partially supported by the DARPA VIRAT program and NSF award IIS to several kinds of activity recognition systems. For example, in a surveillance system, the interest could
McTiernan, James M.
Forward Modeling of Active Region Coronal Emissions. II. Implications for Coronal Heating of Contents and more related content is available Home Search Collections Journals About Contact us My IOPscience #12;FORWARD MODELING OF ACTIVE REGION CORONAL EMISSIONS. II. IMPLICATIONS FOR CORONAL HEATING L. L
Modeling and Field Test Planning Activities in Support of Disposal of Heat-Generating Waste in Salt
Rutqvist, Jonny; Blanco Martin, Laura; Mukhopadhyay, Sumit; Houseworth, Jim; Birkholzer, Jens
2014-09-26T23:59:59.000Z
The modeling efforts in support of the field test planning conducted at LBNL leverage on recent developments of tools for modeling coupled thermal-hydrological-mechanical-chemical (THMC) processes in salt and their effect on brine migration at high temperatures. This work includes development related to, and implementation of, essential capabilities, as well as testing the model against relevant information and published experimental data related to the fate and transport of water. These are modeling capabilities that will be suitable for assisting in the design of field experiment, especially related to multiphase flow processes coupled with mechanical deformations, at high temperature. In this report, we first examine previous generic repository modeling results, focusing on the first 20 years to investigate the expected evolution of the different processes that could be monitored in a full-scale heater experiment, and then present new results from ongoing modeling of the Thermal Simulation for Drift Emplacement (TSDE) experiment, a heater experiment on the in-drift emplacement concept at the Asse Mine, Germany, and provide an update on the ongoing model developments for modeling brine migration. LBNL also supported field test planning activities via contributions to and technical review of framework documents and test plans, as well as participation in workshops associated with field test planning.
Numerical study of high heat ux pool boiling heat transfer Ying He a,*, Masahiro Shoji b
Maruyama, Shigeo
Numerical study of high heat ¯ux pool boiling heat transfer Ying He a,*, Masahiro Shoji b , Shigeo simulation model of boiling heat transfer is proposed based on a numerical macrolayer model [S. Maruyama, M. Shoji, S. Shimizu, A numerical simulation of transition boiling heat transfer, in: Proceedings
Model Based Identification of Transcription Factor Regulatory Activity via Markov Chain Monte Carlo
Rogers, Simon
,Khanin,Girolami (Glasgow) MCMC for TFA MASAMB 2006 2 / 43 #12;Outline 1 Motivation Regulatory Networks Regulation 2 Model,Khanin,Girolami (Glasgow) MCMC for TFA MASAMB 2006 4 / 43 #12;Modeling Regulatory Networks Considerable effort has gone linear Rogers,Khanin,Girolami (Glasgow) MCMC for TFA MASAMB 2006 4 / 43 #12;Modeling Regulatory Networks
NumericalS imulation of Cooling Gas Injection Using
NumericalS imulation of Cooling Gas Injection Using Adaptive Multiscale Techniques Wolfgang Dahmen words:fi nite volume method,fi lm cooling, cooling gas injection, multiscale techniques, grid adaptation#ciency is investigated. Keywords: Finite Volum Method,Film cooling, Cooling gas injection, Multiscale techniques, Grid
Modeling, Analysis and Numerical Approximations of Image ...
... fields, which have a broad range of applications in science, engineering and industry. Not long ago, statistical and ad hoc methods had been main tools for studying and analyzing image processing and computer vision problems. ... interesting and challenging mathematical problems in the areas of Calculus of Variation, ...
Numerical simulation of sandstone reservoir models
Gross, Stephen Joseph
1983-01-01T23:59:59.000Z
. Case 3 - Alternatin h1 h and low ermeabilities Waterflood performance of the Case 3 reservoir is shown in Figures 19 and 20. The process 1s practically rate insensitive for both the high and low viscosity ratio cases because of the ex istence... The results of the water flood study indicate that lower rates result i n higher waterflood oil recoveries from heterogeneous reservoirs, particularly where high oil-water viscosity ratios exist. These results support the conclusions of Jordan et. al...
numerical modeling | OpenEI Community
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OpenEI Community - numerical modeling
AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page onYou are now leaving Energy.gov You are now leaving Energy.gov You are beingZealand Jump to: navigation, searchOfRoseConcernsCompany Oil and GasOff<div/0 en TheResultnotes-call
Thorn, Catherine A. (Catherine Ann), 1980-
2010-01-01T23:59:59.000Z
Parallel cortico-basal ganglia loops are thought to give rise to a diverse set of limbic, associative and motor functions, but little is known about how these loops operate and how their neural activities evolve during ...
Karameh, Fadi Nabih
2002-01-01T23:59:59.000Z
The electroencephalogram, or EEG, is a recording of the field potential generated by the electric activity of neuronal populations of the brain. Its utility has long been recognized as a monitor which reflects the vigilance ...
Understanding, Modeling and Predicting Hidden Solder Joint Shape Using Active Thermography
Giron Palomares, Jose
2012-07-16T23:59:59.000Z
Characterizing hidden solder joint shapes is essential for electronics reliability. Active thermography is a methodology to identify hidden defects inside an object by means of surface abnormal thermal response after applying a heat flux...
NUMERICAL SOLUTION OF BIVARIATE AND POLYANALYTIC POLYNOMIAL SYSTEMS
problem in robotics, computer modeling and graphics, computational geometry and numerical optimization. We) the Research Council KU Leuven: (a) OT/10/038, (b) PF/10/002 Optimization in Engineering (OPTEC), (2
NUMERICAL SOLUTION OF BIVARIATE AND POLYANALYTIC POLYNOMIAL SYSTEMS
problem in robotics, computer modeling and graphics, computational geometry and numerical optimization. We) the Research Council KU Leuven: (a) project OT/10/038, (b) CoE EF/05/006 Optimization in Engineering (OPTEC
An investigation of the numerical treatment of condensation
Sasson, Joseph
The simulation of complete condensation continues to challenge the numerical methods currently used for multi-phase flow modeling; especially at low pressures, the change of phase process from a two-phase mixture to liquid ...
Numerical investigation of the heating process inside an industrial furnace
Wolper, Pierre
Numerical investigation of the heating process inside an industrial furnace Proposition: Combined furnace taking into account convective, conductive and radiative heat transfer. The model: Catalysis, Energy Materials, Performance Materials and Recycling. Each business area is divided into market
Mathiesen, Patrick; Kleissl, Jan
2011-01-01T23:59:59.000Z
transport and numerical weather modeling. J. Applied cross correlations. Weather and Forecasting, 8:4, 401?of radiation for numerical weather prediction and climate
activity-based interaction models: Topics by E-print Network
Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)
Szilagyi a is modeled with a spatially and temporally discretized version of the linear kinematic wave equation written-aquifer interactions; Baseflow separation; Flow routing;...
Review of Regional Locomotive Emission Modeling and the Constraints Posed by Activity Data
Gould, Gregory; Niemeier, Debbie A.
2009-01-01T23:59:59.000Z
Accessed July 21, 2008. Booz Allen Hamilton Inc. LocomotiveBoard, Sacramento, 1991. Booz Allen Hamilton Inc. Report onemission model. Booz Allen Hamilton was hired to develop the