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1

Parallel Cell Projection Rendering of Adaptive Mesh Refinement Data  

Science Conference Proceedings (OSTI)

Adaptive Mesh Refinement (AMR) is a technique used in numerical simulations to automatically refine (or de-refine) certain regions of the physical domain in a finite difference calculation. AMR data consists of nested hierarchies of data grids. As AMR ... Keywords: volume rendering, adaptive mesh refinement, load balancing, multi-grid methods, parallel rendering, visualization

Gunther H. Weber; Martin Ohler; Oliver Kreylos; John M. Shalf; E. Wes Bethel; Bernd Hamann; Gerik Scheuermann

2003-10-01T23:59:59.000Z

2

Presented by Adaptive Hybrid Mesh Refinement for  

E-Print Network (OSTI)

meters. · Orography plays an important role in determining the strength and location of the atmospheric on orographic field data Hybrid adapted geodesic mesh based on orographic field data Structured adapted spherical mesh based on orographic field data #12;7 Khamayseh_ITAPS_SC07 h-Adaptive hybrid mesh generation

3

Visualization Tools for Adaptive Mesh Refinement Data  

SciTech Connect

Adaptive Mesh Refinement (AMR) is a highly effective method for simulations that span a large range of spatiotemporal scales, such as astrophysical simulations that must accommodate ranges from interstellar to sub-planetary. Most mainstream visualization tools still lack support for AMR as a first class data type and AMR code teams use custom built applications for AMR visualization. The Department of Energy's (DOE's) Science Discovery through Advanced Computing (SciDAC) Visualization and Analytics Center for Enabling Technologies (VACET) is currently working on extending VisIt, which is an open source visualization tool that accommodates AMR as a first-class data type. These efforts will bridge the gap between general-purpose visualization applications and highly specialized AMR visual analysis applications. Here, we give an overview of the state of the art in AMR visualization research and tools and describe how VisIt currently handles AMR data.

Weber, Gunther H.; Beckner, Vincent E.; Childs, Hank; Ligocki,Terry J.; Miller, Mark C.; Van Straalen, Brian; Bethel, E. Wes

2007-05-09T23:59:59.000Z

4

Visualization of Scalar Adaptive Mesh Refinement Data  

SciTech Connect

Adaptive Mesh Refinement (AMR) is a highly effective computation method for simulations that span a large range of spatiotemporal scales, such as astrophysical simulations, which must accommodate ranges from interstellar to sub-planetary. Most mainstream visualization tools still lack support for AMR grids as a first class data type and AMR code teams use custom built applications for AMR visualization. The Department of Energy's (DOE's) Science Discovery through Advanced Computing (SciDAC) Visualization and Analytics Center for Enabling Technologies (VACET) is currently working on extending VisIt, which is an open source visualization tool that accommodates AMR as a first-class data type. These efforts will bridge the gap between general-purpose visualization applications and highly specialized AMR visual analysis applications. Here, we give an overview of the state of the art in AMR scalar data visualization research.

VACET; Weber, Gunther; Weber, Gunther H.; Beckner, Vince E.; Childs, Hank; Ligocki, Terry J.; Miller, Mark C.; Van Straalen, Brian; Bethel, E. Wes

2007-12-06T23:59:59.000Z

5

Hierarchical Partitioning Techniques for Structured Adaptive Mesh Refinement Applications  

Science Conference Proceedings (OSTI)

This paper presents the design and preliminary evaluation of hierarchical partitioning and load-balancing techniques for distributed structured adaptive mesh refinement (SAMR) applications. The overall goal of these techniques is to enable the load distribution ... Keywords: distributed computing, dynamic load balancing, hierarchical partitioning algorithm, structured adaptive mesh refinement

Xiaolin Li; Manish Parashar

2004-06-01T23:59:59.000Z

6

Adaptive Mesh Refinement for Characteristic Grids  

E-Print Network (OSTI)

I consider techniques for Berger-Oliger adaptive mesh refinement (AMR) when numerically solving partial differential equations with wave-like solutions, using characteristic (double-null) grids. Such AMR algorithms are naturally recursive, and the best-known past Berger-Oliger characteristic AMR algorithm, that of Pretorius & Lehner (J. Comp. Phys. 198 (2004), 10), recurses on individual "diamond" characteristic grid cells. This leads to the use of fine-grained memory management, with individual grid cells kept in 2-dimensional linked lists at each refinement level. This complicates the implementation and adds overhead in both space and time. Here I describe a Berger-Oliger characteristic AMR algorithm which instead recurses on null \\emph{slices}. This algorithm is very similar to the usual Cauchy Berger-Oliger algorithm, and uses relatively coarse-grained memory management, allowing entire null slices to be stored in contiguous arrays in memory. The algorithm is very efficient in both space and time. I describe discretizations yielding both 2nd and 4th order global accuracy. My code implementing the algorithm described here is included in the electronic supplementary materials accompanying this paper, and is freely available to other researchers under the terms of the GNU general public license.

Jonathan Thornburg

2009-08-31T23:59:59.000Z

7

Dynamic repartitioning of adaptively refined meshes  

Science Conference Proceedings (OSTI)

One ingredient which is viewed as vital to the successful conduct of many large-scale numerical simulations is the ability to dynamically repartition the underlying adaptive finite element mesh among the processors so that the computations are balanced ... Keywords: multilevel diffusion, multilevel graph repartitioning, scratch-remap, wavefront diffusion

Kirk Schloegel; George Karypis; Vipin Kumar

1998-11-01T23:59:59.000Z

8

Block-structured adaptive mesh refinement - theory, implementation and application  

SciTech Connect

Structured adaptive mesh refinement (SAMR) techniques can enable cutting-edge simulations of problems governed by conservation laws. Focusing on the strictly hyperbolic case, these notes explain all algorithmic and mathematical details of a technically relevant implementation tailored for distributed memory computers. An overview of the background of commonly used finite volume discretizations for gas dynamics is included and typical benchmarks to quantify accuracy and performance of the dynamically adaptive code are discussed. Large-scale simulations of shock-induced realistic combustion in non-Cartesian geometry and shock-driven fluid-structure interaction with fully coupled dynamic boundary motion demonstrate the applicability of the discussed techniques for complex scenarios.

Deiterding, Ralf [ORNL

2011-01-01T23:59:59.000Z

9

RAM: a Relativistic Adaptive Mesh Refinement Hydrodynamics Code  

SciTech Connect

The authors have developed a new computer code, RAM, to solve the conservative equations of special relativistic hydrodynamics (SRHD) using adaptive mesh refinement (AMR) on parallel computers. They have implemented a characteristic-wise, finite difference, weighted essentially non-oscillatory (WENO) scheme using the full characteristic decomposition of the SRHD equations to achieve fifth-order accuracy in space. For time integration they use the method of lines with a third-order total variation diminishing (TVD) Runge-Kutta scheme. They have also implemented fourth and fifth order Runge-Kutta time integration schemes for comparison. The implementation of AMR and parallelization is based on the FLASH code. RAM is modular and includes the capability to easily swap hydrodynamics solvers, reconstruction methods and physics modules. In addition to WENO they have implemented a finite volume module with the piecewise parabolic method (PPM) for reconstruction and the modified Marquina approximate Riemann solver to work with TVD Runge-Kutta time integration. They examine the difficulty of accurately simulating shear flows in numerical relativistic hydrodynamics codes. They show that under-resolved simulations of simple test problems with transverse velocity components produce incorrect results and demonstrate the ability of RAM to correctly solve these problems. RAM has been tested in one, two and three dimensions and in Cartesian, cylindrical and spherical coordinates. they have demonstrated fifth-order accuracy for WENO in one and two dimensions and performed detailed comparison with other schemes for which they show significantly lower convergence rates. Extensive testing is presented demonstrating the ability of RAM to address challenging open questions in relativistic astrophysics.

Zhang, Wei-Qun; /KIPAC, Menlo Park; MacFadyen, Andrew I.; /Princeton, Inst. Advanced Study

2005-06-06T23:59:59.000Z

10

Enzo-P / Cello: scalable adaptive mesh refinement for astrophysics and cosmology  

Science Conference Proceedings (OSTI)

Cello is a highly-scalable object-oriented adaptive mesh refinement (AMR) framework currently under development. While Cello is expected to be usable within multiple scientific problem domains, we specifically target specialized requirements of astrophysics ...

James Bordner; Michael L. Norman

2012-07-01T23:59:59.000Z

11

Adaptive Multiresolution or Adaptive Mesh Refinement? A Case Study for 2D Euler Equations  

SciTech Connect

We present adaptive multiresolution (MR) computations of the two-dimensional compressible Euler equations for a classical Riemann problem. The results are then compared with respect to accuracy and computational efficiency, in terms of CPU time and memory requirements, with the corresponding finite volume scheme on a regular grid. For the same test-case, we also perform computations using adaptive mesh refinement (AMR) imposing similar accuracy requirements. The results thus obtained are compared in terms of computational overhead and compression of the computational grid, using in addition either local or global time stepping strategies. We preliminarily conclude that the multiresolution techniques yield improved memory compression and gain in CPU time with respect to the adaptive mesh refinement method.

Deiterding, Ralf [ORNL; Domingues, Margarete O. [Laboratorio Associado de Computacao e Matematica Aplicada (LAC), Sao Paulo; Gomes, Sonia M. [Universidade Estadual de Campinas, Sao Paulo; Roussel, Olivier [Universite d'Aix-Marseille; Schneider, Kai [Universite d'Aix-Marseille

2009-01-01T23:59:59.000Z

12

Performance characteristics of an adaptive mesh refinement calculation on scalar and vector platforms  

Science Conference Proceedings (OSTI)

Adaptive mesh refinement (AMR) is a powerful technique that reduces the resources necessary to solve otherwise intractable problems in computational science. The AMR strategy solves the problem on a relatively coarse grid, and dynamically refines it ... Keywords: IBM power3 and power4, SGI, altix, cray X1E, high end computing, hyperCLaw framework, integrated performance monitoring

Michael Welcome; Charles Rendleman; Leonid Oliker; Rupak Biswas

2006-05-01T23:59:59.000Z

13

An adaptive mesh refinement technique for dynamics of solids  

E-Print Network (OSTI)

Kinetic energy using a consistent mass matrix can beKinetic energy using HRZ lumped mass matrix can be writtenenergy using unrefined mesh and a consistent mass matrix can

Trivedi, Abhishek

2007-01-01T23:59:59.000Z

14

Visualization of Time-Dependent Remote Adaptive Mesh Refinement Data Ralf Kaehler  

E-Print Network (OSTI)

addressed the problem of visualizing remote, time- dependent data defined on AMR grids. In order to handle as the network is fast enough and local resources are capable of handling the data, we believe that using remoteVisualization of Time-Dependent Remote Adaptive Mesh Refinement Data Ralf Kaehler Zuse

Andrzejak, Artur

15

Overview of Eulerian Methods and Block Adaptive Mesh Refinement Techniques at Sandia  

National Nuclear Security Administration (NNSA)

Crawford, D.A. et al. 1 Crawford, D.A. et al. 1 Overview of Eulerian Methods and Block Adaptive Mesh Refinement Techniques at Sandia D. A. Crawford* and D. M. Hensinger* * Sandia National Laboratories, Albuquerque, New Mexico, USA. Multi-material shock-physics Eulerian codes have undergone several generations of refinement in as many decades at Sandia. The widely used code, CTH, can trace its lineage to the one- and two-dimensional codes CHARTD and CSQ. An adaptive mesh refinement (AMR) strategy has been implemented in CTH, providing improved performance and memory utilization and evidence of improved scaling for large problems. The ALE (Arbitrary Lagrangian Eulerian) code ALEGRA combines the multi- material shock physics capabilities found in CTH with a finite element

16

A Parallel Ocean Model With Adaptive Mesh Refinement Capability For Global Ocean Prediction  

DOE Green Energy (OSTI)

An ocean model with adaptive mesh refinement (AMR) capability is presented for simulating ocean circulation on decade time scales. The model closely resembles the LLNL ocean general circulation model with some components incorporated from other well known ocean models when appropriate. Spatial components are discretized using finite differences on a staggered grid where tracer and pressure variables are defined at cell centers and velocities at cell vertices (B-grid). Horizontal motion is modeled explicitly with leapfrog and Euler forward-backward time integration, and vertical motion is modeled semi-implicitly. New AMR strategies are presented for horizontal refinement on a B-grid, leapfrog time integration, and time integration of coupled systems with unequal time steps. These AMR capabilities are added to the LLNL software package SAMRAI (Structured Adaptive Mesh Refinement Application Infrastructure) and validated with standard benchmark tests. The ocean model is built on top of the amended SAMRAI library. The resulting model has the capability to dynamically increase resolution in localized areas of the domain. Limited basin tests are conducted using various refinement criteria and produce convergence trends in the model solution as refinement is increased. Carbon sequestration simulations are performed on decade time scales in domains the size of the North Atlantic and the global ocean. A suggestion is given for refinement criteria in such simulations. AMR predicts maximum pH changes and increases in CO{sub 2} concentration near the injection sites that are virtually unattainable with a uniform high resolution due to extremely long run times. Fine scale details near the injection sites are achieved by AMR with shorter run times than the finest uniform resolution tested despite the need for enhanced parallel performance. The North Atlantic simulations show a reduction in passive tracer errors when AMR is applied instead of a uniform coarse resolution. No dramatic or persistent signs of error growth in the passive tracer outgassing or the ocean circulation are observed to result from AMR.

Herrnstein, A

2005-09-08T23:59:59.000Z

17

A Predictive Model of Fragmentation using Adaptive Mesh Refinement and a Hierarchical Material Model  

Science Conference Proceedings (OSTI)

Fragmentation is a fundamental material process that naturally spans spatial scales from microscopic to macroscopic. We developed a mathematical framework using an innovative combination of hierarchical material modeling (HMM) and adaptive mesh refinement (AMR) to connect the continuum to microstructural regimes. This framework has been implemented in a new multi-physics, multi-scale, 3D simulation code, NIF ALE-AMR. New multi-material volume fraction and interface reconstruction algorithms were developed for this new code, which is leading the world effort in hydrodynamic simulations that combine AMR with ALE (Arbitrary Lagrangian-Eulerian) techniques. The interface reconstruction algorithm is also used to produce fragments following material failure. In general, the material strength and failure models have history vector components that must be advected along with other properties of the mesh during remap stage of the ALE hydrodynamics. The fragmentation models are validated against an electromagnetically driven expanding ring experiment and dedicated laser-based fragmentation experiments conducted at the Jupiter Laser Facility. As part of the exit plan, the NIF ALE-AMR code was applied to a number of fragmentation problems of interest to the National Ignition Facility (NIF). One example shows the added benefit of multi-material ALE-AMR that relaxes the requirement that material boundaries must be along mesh boundaries.

Koniges, A E; Masters, N D; Fisher, A C; Anderson, R W; Eder, D C; Benson, D; Kaiser, T B; Gunney, B T; Wang, P; Maddox, B R; Hansen, J F; Kalantar, D H; Dixit, P; Jarmakani, H; Meyers, M A

2009-03-03T23:59:59.000Z

18

ADER-WENO Finite Volume Schemes with Space-Time Adaptive Mesh Refinement  

E-Print Network (OSTI)

We present the first high order one-step ADER-WENO finite volume scheme with Adaptive Mesh Refinement (AMR) in multiple space dimensions. High order spatial accuracy is obtained through a WENO reconstruction, while a high order one-step time discretization is achieved using a local space-time discontinuous Galerkin predictor method. Due to the one-step nature of the underlying scheme, the resulting algorithm is particularly well suited for an AMR strategy on space-time adaptive meshes, i.e.with time-accurate local time stepping. The AMR property has been implemented 'cell-by-cell', with a standard tree-type algorithm, while the scheme has been parallelized via the Message Passing Interface (MPI) paradigm. The new scheme has been tested over a wide range of examples for nonlinear systems of hyperbolic conservation laws, including the classical Euler equations of compressible gas dynamics and the equations of magnetohydrodynamics (MHD). High order in space and time have been confirmed via a numerical convergenc...

Dumbser, Michael; Hidalgo, Arturo; Balsara, Dinshaw S

2012-01-01T23:59:59.000Z

19

Performance Characteristics of an Adaptive Mesh RefinementCalculation on Scalar and Vector Platforms  

SciTech Connect

Adaptive mesh refinement (AMR) is a powerful technique thatreduces the resources necessary to solve otherwise in-tractable problemsin computational science. The AMR strategy solves the problem on arelatively coarse grid, and dynamically refines it in regions requiringhigher resolution. However, AMR codes tend to be far more complicatedthan their uniform grid counterparts due to the software infrastructurenecessary to dynamically manage the hierarchical grid framework. Despitethis complexity, it is generally believed that future multi-scaleapplications will increasingly rely on adaptive methods to study problemsat unprecedented scale and resolution. Recently, a new generation ofparallel-vector architectures have become available that promise toachieve extremely high sustained performance for a wide range ofapplications, and are the foundation of many leadership-class computingsystems worldwide. It is therefore imperative to understand the tradeoffsbetween conventional scalar and parallel-vector platforms for solvingAMR-based calculations. In this paper, we examine the HyperCLaw AMRframework to compare and contrast performance on the Cray X1E, IBM Power3and Power5, and SGI Altix. To the best of our knowledge, this is thefirst work that investigates and characterizes the performance of an AMRcalculation on modern parallel-vector systems.

Welcome, Michael; Rendleman, Charles; Oliker, Leonid; Biswas, Rupak

2006-01-31T23:59:59.000Z

20

A low numerical dissipation patch-based adaptive mesh refinement method for large-eddy simulation of compressible flows  

Science Conference Proceedings (OSTI)

We present a methodology for the large-eddy simulation of compressible flows with a low-numerical dissipation scheme and structured adaptive mesh refinement (SAMR). A description of a conservative, flux-based hybrid numerical method that uses both centered ... Keywords: Compressible flow, LES, Numerical methods, SAMR, Turbulence

C. Pantano; R. Deiterding; D. J. Hill; D. I. Pullin

2007-01-01T23:59:59.000Z

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


21

Adaptive Mesh Refinement Solution Techniques for the Multigroup SN Transport Equation Using a Higher-Order Discontinuous Finite Element Method  

E-Print Network (OSTI)

In this dissertation, we develop Adaptive Mesh Refinement (AMR) techniques for the steady-state multigroup SN neutron transport equation using a higher-order Discontinuous Galerkin Finite Element Method (DGFEM). We propose two error estimations, a projection-based estimator and a jump-based indicator, both of which are shown to reliably drive the spatial discretization error down using h-type AMR. Algorithms to treat the mesh irregularity resulting from the local refinement are implemented in a matrix-free fashion. The DGFEM spatial discretization scheme employed in this research allows the easy use of adapted meshes and can, therefore, follow the physics tightly by generating group-dependent adapted meshes. Indeed, the spatial discretization error is controlled with AMR for the entire multigroup SNtransport simulation, resulting in group-dependent AMR meshes. The computing efforts, both in memory and CPU-time, are significantly reduced. While the convergence rates obtained using uniform mesh refinement are limited by the singularity index of transport solution (3/2 when the solution is continuous, 1/2 when it is discontinuous), the convergence rates achieved with mesh adaptivity are superior. The accuracy in the AMR solution reaches a level where the solution angular error (or ray effects) are highlighted by the mesh adaptivity process. The superiority of higherorder calculations based on a matrix-free scheme is verified on modern computing architectures. A stable symmetric positive definite Diffusion Synthetic Acceleration (DSA) scheme is devised for the DGFEM-discretized transport equation using a variational argument. The Modified Interior Penalty (MIP) diffusion form used to accelerate the SN transport solves has been obtained directly from the DGFEM variational form of the SN equations. This MIP form is stable and compatible with AMR meshes. Because this MIP form is based on a DGFEM formulation as well, it avoids the costly continuity requirements of continuous finite elements. It has been used as a preconditioner for both the standard source iteration and the GMRes solution technique employed when solving the transport equation. The variational argument used in devising transport acceleration schemes is a powerful tool for obtaining transportconforming diffusion schemes. xuthus, a 2-D AMR transport code implementing these findings, has been developed for unstructured triangular meshes.

Wang, Yaqi

2009-05-01T23:59:59.000Z

22

Self-gravitational Magnetohydrodynamics with Adaptive Mesh Refinement for Protostellar Collapse  

E-Print Network (OSTI)

A new numerical code, called SFUMATO, for solving self-gravitational magnetohydrodynamics (MHD) problems using adaptive mesh refinement (AMR) is presented. A block-structured grid is adopted as the grid of the AMR hierarchy. The total variation diminishing (TVD) cell-centered scheme is adopted as the MHD solver, with hyperbolic cleaning of the divergence error of the magnetic field also implemented. The MHD solver exhibits a second-order accuracy in convergence tests of linearized MHD waves. The self-gravity is solved using a multigrid method composed of (1) a full multigrid (FMG)-cycle on the AMR hierarchical grids, (2) a V-cycle on these grids, and (3) an FMG-cycle on the base grid. The multigrid method exhibits spatial second-order accuracy, fast convergence, and scalability. The numerical fluxes are conserved by using a refluxing procedure in both the MHD solver and the multigrid method. Several tests are performed and the results indicate that the solutions are consistent with previously published results. Key words: hydrodynamics — ISM: clouds — magnetohydrodynamics: MHD — methods: numerical —- stars: formation 1.

Tomoaki Matsumoto

2007-01-01T23:59:59.000Z

23

HIGH-RESOLUTION SIMULATIONS OF CONVECTION PRECEDING IGNITION IN TYPE Ia SUPERNOVAE USING ADAPTIVE MESH REFINEMENT  

E-Print Network (OSTI)

We extend our previous three-dimensional, full-star simulations of the final hours of convection preceding ignition in Type Ia supernovae to higher resolution using the adaptive mesh refinement capability of our low Mach number code, MAESTRO. We report the statistics of the ignition of the first flame at an effective 4.34 km resolution and general flow field properties at an effective 2.17 km resolution. We find that off-center ignition is likely, with radius of 50 km most favored and a likely range of 40–75 km. This is consistent with our previous coarser (8.68 km resolution) simulations, implying that we have achieved sufficient resolution in our determination of likely ignition radii. The dynamics of the last few hot spots preceding ignition suggest that a multiple ignition scenario is not likely. With improved resolution, we can more clearly see the general flow pattern in the convective region, characterized by a strong outward plume with a lower speed recirculation. We show that the convective core is turbulent with a Kolmogorov spectrum and has a lower turbulent intensity and larger integral length scale than previously thought (on the order of 16 km s?1 and 200 km, respectively), and we discuss the potential consequences for the first flames. Key words: convection – hydrodynamics – methods: numerical – nuclear reactions, nucleosynthesis, abundances – supernovae: general – white dwarfs Online-only material: color figures 1.

A. Nonaka; A. J. Aspden; M. Zingale; A. S. Almgren; J. B. Bell; S. E. Woosley

2012-01-01T23:59:59.000Z

24

Systems Engineering For High Performance Computing Software: The Hdda/dagh Infrastructure For Implementation Of Parallel Structured Adaptive Mesh Refinement  

E-Print Network (OSTI)

. This paper defines, describes and illustrates a systems engineering process for development of software systems implementing high performance computing applications. The example which drives the creation of this process is development of a flexible and extendible program development infrastructure for parallel structured adaptive meshes, the HDDA/DAGH package. The fundamental systems engineering principles used (hierarchical abstractions based on separation of concerns) are well-known but are not commonly applied in the context of high performance computing software. Application of these principles will be seen to enable implementation of an infrastructure which combines breadth of applicability and portability with high performance. Key words. Software systems engineering, Structured adaptive mesh-refinement, High performance software development, Distributed dynamic data-structures. 1. Overview. This paper describes the systems engineering process which was followed in the develop...

Manish Parashar; James; C. Browne

1997-01-01T23:59:59.000Z

25

Voronoi, Delaunay, and Block-Structured Mesh Refinement for Solution of the Shallow-Water Equations on the Sphere  

Science Conference Proceedings (OSTI)

Alternative meshes of the sphere and adaptive mesh refinement could be immensely beneficial for weather and climate forecasts, but it is not clear how mesh refinement should be achieved. A finite-volume model that solves the shallow-water ...

Hilary Weller; Henry G. Weller; Aimé Fournier

2009-12-01T23:59:59.000Z

26

Advanced numerical methods in mesh generation and mesh adaptation  

SciTech Connect

Numerical solution of partial differential equations requires appropriate meshes, efficient solvers and robust and reliable error estimates. Generation of high-quality meshes for complex engineering models is a non-trivial task. This task is made more difficult when the mesh has to be adapted to a problem solution. This article is focused on a synergistic approach to the mesh generation and mesh adaptation, where best properties of various mesh generation methods are combined to build efficiently simplicial meshes. First, the advancing front technique (AFT) is combined with the incremental Delaunay triangulation (DT) to build an initial mesh. Second, the metric-based mesh adaptation (MBA) method is employed to improve quality of the generated mesh and/or to adapt it to a problem solution. We demonstrate with numerical experiments that combination of all three methods is required for robust meshing of complex engineering models. The key to successful mesh generation is the high-quality of the triangles in the initial front. We use a black-box technique to improve surface meshes exported from an unattainable CAD system. The initial surface mesh is refined into a shape-regular triangulation which approximates the boundary with the same accuracy as the CAD mesh. The DT method adds robustness to the AFT. The resulting mesh is topologically correct but may contain a few slivers. The MBA uses seven local operations to modify the mesh topology. It improves significantly the mesh quality. The MBA method is also used to adapt the mesh to a problem solution to minimize computational resources required for solving the problem. The MBA has a solid theoretical background. In the first two experiments, we consider the convection-diffusion and elasticity problems. We demonstrate the optimal reduction rate of the discretization error on a sequence of adaptive strongly anisotropic meshes. The key element of the MBA method is construction of a tensor metric from hierarchical edge-based error estimates. We conclude that the quasi-optimal mesh must be quasi-uniform in this metric. All numerical experiments are based on the publicly available Ani3D package, the collection of advanced numerical instruments.

Lipnikov, Konstantine [Los Alamos National Laboratory; Danilov, A [MOSCOW, RUSSIA; Vassilevski, Y [MOSCOW, RUSSIA; Agonzal, A [UNIV OF LYON

2010-01-01T23:59:59.000Z

27

/adaptive_mesh  

Science Conference Proceedings (OSTI)

... The mesh-energy function is non-linear and optimization is not straightforward. Optimization can get stalled by local minima ...

2013-08-23T23:59:59.000Z

28

Adaptive mesh generation for curved domains  

Science Conference Proceedings (OSTI)

This paper considers the technologies needed to support the creation of adaptively constructed meshes for general curved three-dimensional domains and outlines one set of solutions for providing them. A brief review of an effective way to integrate mesh ... Keywords: adaptive meshes, anisotropic meshes, curved meshes

Mark S. Shephard; Joseph E. Flaherty; Kenneth E. Jansen; Xiangrong Li; Xiaojuan Luo; Nicolas Chevaugeon; Jean-François Remacle; Mark W. Beall; Robert M. O'Bara

2005-02-01T23:59:59.000Z

29

Efficient adaptive meshing of parametric models  

Science Conference Proceedings (OSTI)

Parametric modeling is becoming the representation of choice for most modern solid modelers. However, when generating the finite-element mesh of the model for simulation and analysis, most meshing tools ignore the parametric information and use only ... Keywords: adaptivity, mesh generation, parametric models

Alla Sheffer; Alper Üngör

2001-05-01T23:59:59.000Z

30

Appears in the 7th Workshop on Mining Scientific and Engineering Datasets 2004 A Grid-based Clustering Algorithm using Adaptive Mesh Refinement  

E-Print Network (OSTI)

irregular data distributions, using a single uniform grid may not be sufficient to obtain a required, for highly irregular or concentrated data distributions, a grid mesh with very fine granularity, which first employ a uniform grid to collect the regional statistic data and, then, perform

Kuzmanovic, Aleksandar

31

Adaptive surface meshes coarsening with guaranteed quality and topology  

Science Conference Proceedings (OSTI)

In this paper, we present a novel surface meshes coarsening algorithm for generating hierarchical skin surface meshes with decreasing size and guaranteed quality. Each coarse surface mesh is adaptive to the surface curvature and maintains the topology ...

Xinwei Shi; Patrice Koehl

2009-05-01T23:59:59.000Z

32

Dynamic Adaptive Multimesh Refinement for Coupled Physics Equations Applicable to Nuclear Engineering  

E-Print Network (OSTI)

The processes studied by nuclear engineers generally include coupled physics phenomena (Thermal-Hydraulics, Neutronics, Material Mechanics, etc.) and modeling such multiphysics processes numerically can be computationally intensive. A way to reduce the computational burden is to use spatial meshes that are optimally suited for a specific solution; such meshes are obtained through a process known as Adaptive Mesh Refinement (AMR). AMR can be especially useful for modeling multiphysics phenomena by allowing each solution component to be computed on an independent mesh (Multimesh AMR). Using AMR on time dependent problems requires the spatial mesh to change in time as the solution changes in time. Current algorithms presented in the literature address this concern by adapting the spatial mesh at every time step, which can be inefficient. This Thesis proposes an algorithm for saving computational resources by using a spatially adapted mesh for multiple time steps, and only adapting the spatial mesh when the solution has changed significantly. This Thesis explores the mechanisms used to determine when and where to spatially adapt for time dependent, coupled physics problems. The algorithm is implemented using the Deal.ii fiinite element library [1, 2], in 2D and 3D, and is tested on a coupled neutronics and heat conduction problem in 2D. The algorithm is shown to perform better than a uniformly refined static mesh and, in some cases, a mesh that is spatially adapted at every time step.

Dugan, Kevin

2013-08-01T23:59:59.000Z

33

Engine spray combustion modeling using unified spray model with dynamic mesh refinement.  

E-Print Network (OSTI)

??The primary objective of this study is to improve the spray and combustion modeling of internal combustion engines using dynamic mesh refinement. The first part… (more)

Kolakaluri, Ravi

2009-01-01T23:59:59.000Z

34

Optimization Online - Use of quadratic models with mesh adaptive ...  

E-Print Network (OSTI)

Mar 6, 2011 ... Use of quadratic models with mesh adaptive direct search for constrained black box optimization. Andrew R Conn (arconn ***at*** us.ibm.com)

35

Automatic Mesh Adaptivity for Hybrid Monte Carlo/Deterministic Neutronics Modeling of Fusion Energy Systems  

SciTech Connect

Three mesh adaptivity algorithms were developed to facilitate and expedite the use of the CADIS and FW-CADIS hybrid Monte Carlo/deterministic techniques in accurate full-scale neutronics simulations of fusion energy systems with immense sizes and complicated geometries. First, a macromaterial approach enhances the fidelity of the deterministic models without changing the mesh. Second, a deterministic mesh refinement algorithm generates meshes that capture as much geometric detail as possible without exceeding a specified maximum number of mesh elements. Finally, a weight window coarsening algorithm decouples the weight window mesh and energy bins from the mesh and energy group structure of the deterministic calculations in order to remove the memory constraint of the weight window map from the deterministic mesh resolution. The three algorithms were used to enhance an FW-CADIS calculation of the prompt dose rate throughout the ITER experimental facility and resulted in a 23.3% increase in the number of mesh tally elements in which the dose rates were calculated in a 10-day Monte Carlo calculation. Additionally, because of the significant increase in the efficiency of FW-CADIS simulations, the three algorithms enabled this difficult calculation to be accurately solved on a regular computer cluster, eliminating the need for a world-class super computer.

Ibrahim, Ahmad M [ORNL; Wilson, P. [University of Wisconsin; Sawan, M. [University of Wisconsin; Mosher, Scott W [ORNL; Peplow, Douglas E. [ORNL; Grove, Robert E [ORNL

2013-01-01T23:59:59.000Z

36

Kinetic Solvers with Adaptive Mesh in Phase Space  

E-Print Network (OSTI)

An Adaptive Mesh in Phase Space (AMPS) methodology has been developed for solving multi-dimensional kinetic equations by the discrete velocity method. A Cartesian mesh for both configuration (r) and velocity (v) spaces is produced using a tree of trees data structure. The mesh in r-space is automatically generated around embedded boundaries and dynamically adapted to local solution properties. The mesh in v-space is created on-the-fly for each cell in r-space. Mappings between neighboring v-space trees implemented for the advection operator in configuration space. We have developed new algorithms for solving the full Boltzmann and linear Boltzmann equations with AMPS. Several recent innovations were used to calculate the full Boltzmann collision integral with dynamically adaptive mesh in velocity space: importance sampling, multi-point projection method, and the variance reduction method. We have developed an efficient algorithm for calculating the linear Boltzmann collision integral for elastic and inelastic...

Arslanbekov, Robert R; Frolova, Anna A

2013-01-01T23:59:59.000Z

37

Laser ray tracing in a parallel arbitrary Lagrangian-Eulerian adaptive mesh refi  

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

ray tracing in a parallel arbitrary Lagrangian-Eulerian adaptive mesh refinement ray tracing in a parallel arbitrary Lagrangian-Eulerian adaptive mesh refinement hydrocode This article has been downloaded from IOPscience. Please scroll down to see the full text article. 2010 J. Phys.: Conf. Ser. 244 032022 (http://iopscience.iop.org/1742-6596/244/3/032022) Download details: IP Address: 50.136.219.251 The article was downloaded on 18/04/2013 at 01:39 Please note that terms and conditions apply. View the table of contents for this issue, or go to the journal homepage for more Home Search Collections Journals About Contact us My IOPscience Laser Ray Tracing in a Parallel Arbitrary Lagrangian-Eulerian Adaptive Mesh Refinement Hydrocode N D Masters 1 , T B Kaiser 1 , R W Anderson 1 , D C Eder 1 , A C Fisher 1 , A E Koniges 2 1 Lawrence Livermore National Laboratory, Livermore, CA U.S.A. 2 National

38

Further Studies of Mesh Refinement: Are Shock-Free Airfoils Truly Shock Free?  

E-Print Network (OSTI)

Further Studies of Mesh Refinement: Are Shock-Free Airfoils Truly Shock Free? Antony Jameson with a hodograph method to be shock-free at M = 0.750 and Cl = 0.629. However, computational fluid dynamics results show a double-shock pattern appear at this design point as the resolution of the grid is enhanced

Stanford University

39

Adaptive computations on conforming quadtree meshes  

E-Print Network (OSTI)

adaptive re?nement for B-spline ?nite element, Int. J.enrichment [6,7] as well as B-splines [8]. These methods

Tabarraei, A; Sukumar, N

2005-01-01T23:59:59.000Z

40

The adaptive GRP scheme for compressible fluid flows over unstructured meshes  

Science Conference Proceedings (OSTI)

Unstructured mesh methods have attracted much attention in CFD community due to the flexibility for dealing with complex geometries and the ability to easily incorporate adaptive (moving) mesh strategies. When the finite volume framework is applied, ... Keywords: Adaptive moving mesh method, Conservative interpolation, GRP solver, Least squares method, Unstructured triangular meshes

Jiequan Li, Yongjin Zhang

2013-06-01T23:59:59.000Z

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


41

AUTOMATIC MESH ADAPTIVITY FOR CADIS AND FW-CADIS NEUTRONICS MODELING OF DIFFICULT SHIELDING PROBLEMS  

Science Conference Proceedings (OSTI)

The hybrid Monte Carlo/deterministic techniques CADIS and FW-CADIS dramatically increase the efficiency of neutronics modeling, but their use in the accurate design analysis of very large and geometrically complex nuclear systems has been restricted by the availability of computing resources for their preliminary deterministic calculations and the large computer memory requirements of their final Monte Carlo calculations. Three automatic mesh adaptivity algorithms were developed to reduce the memory requirements of CADIS and FW-CADIS without sacrificing their efficiency improvement. First, a macromaterial approach enhances the fidelity of the deterministic models without changing the mesh. Second, a deterministic mesh refinement algorithm generates meshes that capture as much geometric detail as possible without exceeding some maximum number of mesh elements. Finally, a weight window coarsening algorithm decouples the weight window mesh from the mesh of the deterministic calculations to remove the memory constraint of the weight window map from the deterministic mesh resolution. The three algorithms were used to calculate the prompt dose rate throughout the entire ITER experimental facility. Compared to a FW-CADIS calculation with the same weight window map memory requirement, using the three algorithms resulted in a 23.3% increase in the regions where the dose rates were calculated in a 10-day Monte Carlo calculation and, additionally, increased the efficiency of the Monte Carlo simulation by a factor of at least 3.4. The three algorithms enabled the accurate performance of this difficult global Monte Carlo calculation, which traditionally needed high performance computing, using a FW-CADIS simulation on a regular computer cluster.

Ibrahim, Ahmad M [ORNL; Wilson, P. [University of Wisconsin; Peplow, Douglas E. [ORNL; Mosher, Scott W [ORNL; Sawan, M. [University of Wisconsin; Wagner, John C [ORNL; Evans, Thomas M [ORNL

2013-01-01T23:59:59.000Z

42

A dynamic mesh refinement technique for Lattice Boltzmann simulations on octree-like grids  

Science Conference Proceedings (OSTI)

In this contribution, we present our new adaptive Lattice Boltzmann implementation within the Peano framework, with special focus on nanoscale particle transport problems. With the continuum hypothesis not holding anymore on these small scales, new physical ... Keywords: Adaptive Cartesian grids, Brownian, Dynamic grid refinement, Fluctuations, Lattice Boltzmann, Multiscale, Particle transport

Philipp Neumann; Tobias Neckel

2013-02-01T23:59:59.000Z

43

Dynamic Repartitioning of Adaptively Refined Meshes Dynamic Repartitioning of Adaptively Refined  

E-Print Network (OSTI)

, the flow of vertices move in a wavefront from overbalanced to underbalanced domains. We present overbalanced to underbalanced domains. We present experimental evaluations of our LMSR and Wavefront Diffusion is in a wavefront from overbalanced domains to underbalanced domains. Our actual serial implementation of Wavefront

Karypis, George

44

Production-quality Tools for Adaptive Mesh Refinement Visualization  

E-Print Network (OSTI)

Office of Advanced Scientific Computing Research, of theAdvanced Scientific Computing Research Computer Science FY

2008-01-01T23:59:59.000Z

45

Hierarchical Partitioning Techniques for Structured Adaptive Mesh Refinement Applications  

E-Print Network (OSTI)

connected end uses and eliminate the associate "vampire load"when not in use, but a uniform test and rating

46

Hierarchical Partitioning Techniques for Structured Adaptive Mesh Refinement (SAMR) Applications  

E-Print Network (OSTI)

- loaded once a month. Using software specifically designed for viewing the data, we can separate out as humans. Vampire Bats? The legend of Dracula, the human vampire, arose long before real blood-drinking bats were even discovered in South America. Vampire bats (of which there are 3 species) were actually

Parashar, Manish

47

Combined heat and power economic dispatch by mesh adaptive direct search algorithm  

Science Conference Proceedings (OSTI)

The optimal utilization of multiple combined heat and power (CHP) systems is a complex problem. Therefore, efficient methods are required to solve it. In this paper, a recent optimization technique, namely mesh adaptive direct search (MADS) is implemented ... Keywords: Combined heat and power, Economic dispatch, Mesh adaptive direct search algorithm, Optimization

Seyyed Soheil Sadat Hosseini; Ali Jafarnejad; Amir Hossein Behrooz; Amir Hossein Gandomi

2011-06-01T23:59:59.000Z

48

Rapid gravity and gravity gradiometry terrain corrections via an adaptive quadtree mesh discretization  

E-Print Network (OSTI)

Rapid gravity and gravity gradiometry terrain corrections via an adaptive quadtree mesh discretization Kristofer Davis1,2 M. Andy Kass1 Yaoguo Li1 1 Center for Gravity, Electrical, and Magnetic Studies of gravity gradiometry surveys utilising an adaptive quadtree mesh discretization. The data- and terrain

49

Robust, multidimensional mesh-motion based on Monge-Kantorovich equidistribution  

Science Conference Proceedings (OSTI)

Mesh-motion (r-refinement) grid adaptivity schemes are attractive due to their potential to minimize the numerical error for a prescribed number of degrees of freedom. However, a key roadblock to a widespread deployment of this class of techniques has ... Keywords: Grid tangling, Mesh adaptation, Mesh-motion, Monge-Ampère, Monge-Kantorovich, Newton-Krylov, r-Refinement

L. Chacón; G. L. Delzanno; J. M. Finn

2011-01-01T23:59:59.000Z

50

Volume Refinement Fairing Isosurfaces  

Science Conference Proceedings (OSTI)

We propose an interpolating refinement method for two- and three-dimensional scalar fields defined on hexahedral grids. Iterative fairing of the underlying contours (isosurfaces) provides the function values of new grid points. Our method can be considered ... Keywords: adaptive mesh refinement, isosurfaces, subdivision, variational modeling, volume fairing

Martin Bertram

2004-10-01T23:59:59.000Z

51

An adaptive mesh method for the simulation of Blade Vortex Interaction  

E-Print Network (OSTI)

An adaptive mesh method for the simulation of parallel ics. Blade Vortex Interaction (BV1) with an active Trailing Edge Flap (TEF) is presented. The two-dimensional 1111-steady problem is solved by a higher order upwind Euler method for an unstructured mesh. A local mesh adaptation technique is employed to maintain vortex strength by capturing the details of the convecting vortex. The computational technique does not require any assumption on the vortex structure, and, therefore is suitable for close interaction of the vortex and the blade. The adaptive method is based on cell subdivisions and allows for frequent mesh adaptation due to its fast speed. To demonstrate the reduction of numerical dissipation of a vortex via mesh adaptation, we first consider a simple case with a convecting vortex in freestream. Finally, we apply tile techniques to examine the effectiveness of an active TEF on BVI in reducing the pressure perturbations at the airfoil leading edge. For the boundary motion due to TEF deployment, a local recessing procedure is utilized to maintain mesh quality by avoiding distorted mesh elements near the flap.

Kim, Kyu-Sup

1998-01-01T23:59:59.000Z

52

An algorithm for transferring 2D arbitrary hp-refined finite element axially symmetric meshes to three dimensions  

E-Print Network (OSTI)

of Petroleum Engineering, The University of Texas in Austin (3) Institute for Computational Engineering and Sciences, ICES, The University of Texas in Austin Abstract The 2D and 3D fully automatic hp adaptive Finite is solved on the coarse and on the fine mesh. The energy norm (H1 Sobolev space norm) difference between

Torres-Verdín, Carlos

53

An accurate performance model of fully adaptive routing in wormhole-switched two-dimensional mesh multicomputers  

Science Conference Proceedings (OSTI)

Numerous analytical performance models have been proposed for deterministic wormhole-routed mesh networks while only a single model, to our best knowledge, has been suggested for fully adaptive wormhole routing in mesh interconnection networks. This ... Keywords: Adaptive wormhole routing, Analytical modeling, Interconnection network, Meshes, Multicomputer, Performance evaluation

H. Hashemi-Najafabadi; H. Sarbazi-Azad; P. Rajabzadeh

2007-11-01T23:59:59.000Z

54

Rate-adaption channel assignment and routing algorithm for multi-channel wirelessMAN mesh networks  

Science Conference Proceedings (OSTI)

Wireless mesh networks provide an easy deployed and extensible solution to access Internet or communicate with each other for both enterprises and individuals. With the help of multi-channel and multi-radio, wireless mesh network can support more traffic ... Keywords: IEEE 802.16, channel assignment, rate-adaption, routing, wireless mesh network

Eric Hsiao-Kuang Wu; Wei-Li Chang; Hsuan-Hao Chan

2007-07-01T23:59:59.000Z

55

Effective out-of-core parallel delaunay mesh refinement using off-the-shelf software  

Science Conference Proceedings (OSTI)

We present three related out-of-core parallel mesh generation algorithms and their implementations for small size computational clusters. Computing out-of-core permits to solve larger problems than otherwise possible on the same hardware setup. Also, ... Keywords: Delaunay, Effective computing, off-the-shelf, wall-clock time

Andriy Kot; Andrey N. Chernikov; Nikos P. Chrisochoides

2011-05-01T23:59:59.000Z

56

A parallel solution - adaptive method for three-dimensional turbulent non-premixed combusting flows  

Science Conference Proceedings (OSTI)

A parallel adaptive mesh refinement (AMR) algorithm is proposed and applied to the prediction of steady turbulent non-premixed compressible combusting flows in three space dimensions. The parallel solution-adaptive algorithm solves the system of partial-differential ... Keywords: Adaptive mesh refinement, Parallel solution-adaptive algorithm, Turbulent combustion, Turbulent diffusion flames, Turbulent non-premixed flames

Xinfeng Gao; Clinton P. T. Groth

2010-05-01T23:59:59.000Z

57

Mesh generation and numerical analysis of a Galerkin method for highly conductive prefractal layers  

Science Conference Proceedings (OSTI)

In this paper we provide a piecewise linear Galerkin approximation of a second order transmission problem across a highly conductive prefractal layer of von Koch type. We firstly generate an appropriate mesh adapted to the geometric shape of the interface ... Keywords: A priori error estimate, Adaptive mesh refinement, Finite element methods, Highly conductive layers, Transmission problems, Von Koch curve

Patrizia Bagnerini; Annalisa Buffa; Elisa Vacca

2013-03-01T23:59:59.000Z

58

An Adaptive Multigrid Barotropic Tropical Cyclone Track Model  

Science Conference Proceedings (OSTI)

This paper describes the application of adaptive multigrid techniques to the problem of tropical cyclone track prediction. Based on the nondivergent barotropic vorticity equation, the model uses an adaptive multigrid method to refine the mesh ...

Scott R. Fulton

2001-01-01T23:59:59.000Z

59

A Parallel Second-Order Adaptive Mesh Algorithm for Incompressible Flow in Porous Media  

Science Conference Proceedings (OSTI)

In this paper we present a second-order accurate adaptive algorithm for solving multiphase, incompressible flows in porous media. We assume a multiphase form of Darcy's law with relative permeabilities given as a function of the phase saturation. The remaining equations express conservation of mass for the fluid constituents. In this setting the total velocity, defined to be the sum of the phase velocities, is divergence-free. The basic integration method is based on a total-velocity splitting approach in which we solve a second-order elliptic pressure equation to obtain a total velocity. This total velocity is then used to recast component conservation equations as nonlinear hyperbolic equations. Our approach to adaptive refinement uses a nested hierarchy of logically rectangular grids with simultaneous refinement of the grids in both space and time. The integration algorithm on the grid hierarchy is a recursive procedure in which coarse grids are advanced in time, fine grids areadvanced multiple steps to reach the same time as the coarse grids and the data atdifferent levels are then synchronized. The single grid algorithm is described briefly,but the emphasis here is on the time-stepping procedure for the adaptive hierarchy. Numerical examples are presented to demonstrate the algorithm's accuracy and convergence properties and to illustrate the behavior of the method.

Pau, George Shu Heng; Almgren, Ann S.; Bell, John B.; Lijewski, Michael J.

2008-04-01T23:59:59.000Z

60

An adaptive grid refinement strategy for the simulation of negative streamers  

Science Conference Proceedings (OSTI)

The evolution of negative streamers during electric breakdown of a non-attaching gas can be described by a two-fluid model for electrons and positive ions. It consists of continuity equations for the charged particles including drift, diffusion and reaction ... Keywords: 52.25.Aj, 52.35.Mw, 52.65.Kj, 52.80.Mj, Adaptive grid refinements, Elliptic-parabolic system, Finite volumes, Negative streamers, Pulled front

C. Montijn; W. Hundsdorfer; U. Ebert

2006-12-01T23:59:59.000Z

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


61

6th International Meshing Roundtable '97  

SciTech Connect

The goal of the 6th International Meshing Roundtable is to bring together researchers and developers from industry, academia, and government labs in a stimulating, open environment for the exchange of technical information related to the meshing process. In the pas~ the Roundtable has enjoyed significant participation born each of these groups from a wide variety of countries. The Roundtable will consist of technical presentations from contributed papers and abstracts, two invited speakers, and two invited panels of experts discussing topics related to the development and use of automatic mesh generation tools. In addition, this year we will feature a "Bring Your Best Mesh" competition and poster session to encourage discussion and participation from a wide variety of mesh generation tool users. The schedule and evening social events are designed to provide numerous opportunities for informal dialog. A proceedings will be published by Sandia National Laboratories and distributed at the Roundtable. In addition, papers of exceptionally high quaIity will be submitted to a special issue of the International Journal of Computational Geometry and Applications. Papers and one page abstracts were sought that present original results on the meshing process. Potential topics include but are got limited to: Unstructured triangular and tetrahedral mesh generation Unstructured quadrilateral and hexahedral mesh generation Automated blocking and structured mesh generation Mixed element meshing Surface mesh generation Geometry decomposition and clean-up techniques Geometry modification techniques related to meshing Adaptive mesh refinement and mesh quality control Mesh visualization Special purpose meshing algorithms for particular applications Theoretical or novel ideas with practical potential Technical presentations from industrial researchers.

White, D.

1997-09-01T23:59:59.000Z

62

Visualization Development Environments 2000 Proceedings Implementing a Visualization Tool for Adaptive Mesh Refinement Data  

E-Print Network (OSTI)

directly supported visualizing AMR data, we chose to extend one, VTK, via its Tcl/Tk interface. This AMR Tcl/Tk [Tcl/Tk] interface. First, we give some context, define the problem we faced, and discuss why Tcl/Tk interface. 1.2 Overall Problem Before we describe the specific structure of the ANAG AMR data

63

Radiation hydrodynamics with Adaptive Mesh Refinement and application to prestellar core collapse. I Methods  

E-Print Network (OSTI)

Radiative transfer has a strong impact on the collapse and the fragmentation of prestellar dense cores. We present the radiation-hydrodynamics solver we designed for the RAMSES code. The method is designed for astrophysical purposes, and in particular for protostellar collapse. We present the solver, using the co-moving frame to evaluate the radiative quantities. We use the popular flux limited diffusion approximation, under the grey approximation (one group of photon). The solver is based on the second-order Godunov scheme of RAMSES for its hyperbolic part, and on an implicit scheme for the radiation diffusion and the coupling between radiation and matter. We report in details our methodology to integrate the RHD solver into RAMSES. We test successfully the method against several conventional tests. For validation in 3D, we perform calculations of the collapse of an isolated 1 M_sun prestellar dense core, without rotation. We compare successfully the results with previous studies using different models for r...

Commercon, Benoit; Audit, Edouard; Hennebelle, Patrick; Chabrier, Gilles

2011-01-01T23:59:59.000Z

64

Query-Driven Visualization of Time-Varying Adaptive Mesh Refinement Data  

Science Conference Proceedings (OSTI)

The visualization and analysis of AMR-based simulations is integral to the process of obtaining new insight in scientific research. We present a new method for performing query-driven visualization and analysis on AMR data, with specific emphasis on time-varying AMR data. Our work introduces a new method that directly addresses the dynamic spatial and temporal properties of AMR grids which challenge many existing visualization techniques. Further, we present the first implementation of query-driven visualization on the GPU that uses a GPU-based indexing structure to both answer queries and efficiently utilize GPU memory. We apply our method to two different science domains to demonstrate its broad applicability.

Gosink, Luke J.; Anderson, John C.; Bethel, E. Wes; Joy, Kenneth I.

2008-08-01T23:59:59.000Z

65

CRASH: A BLOCK-ADAPTIVE-MESH CODE FOR RADIATIVE SHOCK HYDRODYNAMICS-IMPLEMENTATION AND VERIFICATION  

SciTech Connect

We describe the Center for Radiative Shock Hydrodynamics (CRASH) code, a block-adaptive-mesh code for multi-material radiation hydrodynamics. The implementation solves the radiation diffusion model with a gray or multi-group method and uses a flux-limited diffusion approximation to recover the free-streaming limit. Electrons and ions are allowed to have different temperatures and we include flux-limited electron heat conduction. The radiation hydrodynamic equations are solved in the Eulerian frame by means of a conservative finite-volume discretization in either one-, two-, or three-dimensional slab geometry or in two-dimensional cylindrical symmetry. An operator-split method is used to solve these equations in three substeps: (1) an explicit step of a shock-capturing hydrodynamic solver; (2) a linear advection of the radiation in frequency-logarithm space; and (3) an implicit solution of the stiff radiation diffusion, heat conduction, and energy exchange. We present a suite of verification test problems to demonstrate the accuracy and performance of the algorithms. The applications are for astrophysics and laboratory astrophysics. The CRASH code is an extension of the Block-Adaptive Tree Solarwind Roe Upwind Scheme (BATS-R-US) code with a new radiation transfer and heat conduction library and equation-of-state and multi-group opacity solvers. Both CRASH and BATS-R-US are part of the publicly available Space Weather Modeling Framework.

Van der Holst, B.; Toth, G.; Sokolov, I. V.; Myra, E. S.; Fryxell, B.; Drake, R. P. [Department of Atmospheric, Oceanic and Space Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Powell, K. G. [Department of Aerospace Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Holloway, J. P. [Nuclear Engineering and Radiological Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Stout, Q. [Computer Science and Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Adams, M. L.; Morel, J. E. [Department of Nuclear Engineering, Texas A and M University, College Station, TX 77843 (United States); Karni, S. [Department of Mathematics, University of Michigan, Ann Arbor, MI 48109 (United States)

2011-06-01T23:59:59.000Z

66

Adaptive computations using material forces and residual-based error estimators on quadtree meshes  

E-Print Network (OSTI)

enrichment [6, 7] or B-splines [8], and natural neighborAdaptive re?nement for B-spline ?nite element, International

Sukumar, N.; Tabarraei, A.

2007-01-01T23:59:59.000Z

67

BOFAR: buffer occupancy factor based adaptive router for mesh NoCs  

Science Conference Proceedings (OSTI)

If the route computation operation in an adaptive router returns more than one output channels, the selection strategy chooses one from them based on the congestion metric used. The effectiveness of a selection strategy depends on what metric is used ... Keywords: adaptive routers, buffer occupancy, network-on-chip

John Jose; J. Shiva Shankar; K. V. Mahathi; Damarla Kranthi Kumar; Madhu Mutyam

2011-12-01T23:59:59.000Z

68

Identification of Unknown Interface Locations in a Source/Shield System Using the Mesh Adaptive Direct Search Method  

SciTech Connect

The Levenberg-Marquardt (or simply Marquardt) and differential evolution (DE) optimization methods were recently applied to solve inverse transport problems. The Marquardt method is fast but convergence of the method is dependent on the initial guess. While it has been shown to work extremely well at finding an optimum independent of the initial guess, the DE method does not provide a global optimal solution in some problems. In this paper, we apply the Mesh Adaptive Direct Search (MADS) algorithm to solve the inverse problem of material interface location identification in one-dimensional spherical radiation source/shield systems, and we compare the results obtained by MADS to those obtained by Levenberg-Marquardt and DE.

Armstrong, Jerawan C. [Los Alamos National Laboratory; Favorite, Jeffrey A. [Los Alamos National Laboratory

2012-06-20T23:59:59.000Z

69

A Characterization of Distribution Techniques for Dynamic Adaptive Grid Hierarchies  

E-Print Network (OSTI)

A Characterization of Distribution Techniques for Dynamic Adaptive Grid Hierarchies Samip Bhavsar for distributed adaptive grid hierarchies that underlie parallel adaptive mesh-refinement (AMR) techniques is the development of a policy driven tool for automated configuration and run-time management of distributed

Parashar, Manish

70

Adaptive Grid Refinement for Two-Dimensional and Three-Dimensional Nonhydrostatic Atmospheric Flow  

Science Conference Proceedings (OSTI)

Although atmospheric phenomena tend to be localized in both time and space, numerical models generally employ only uniform discretizations or fixed nested grids. An adaptive grid technique implemented in 2D and 3D nonhydrostatic elastic ...

William C. Skamarock; Joseph B. Klemp

1993-03-01T23:59:59.000Z

71

Truncation Error Estimates for Refinement Criteria in Nested and Adaptive Models  

Science Conference Proceedings (OSTI)

Truncation error estimates are considered as criteria for fine-grid placement and movement in nested and adaptive finite-difference atmospheric models. A simple method for calculating the truncation error at any time during an integration is ...

William C. Skamrock

1989-04-01T23:59:59.000Z

72

An Adaptive Multimoment Global Model on a Cubed Sphere  

Science Conference Proceedings (OSTI)

An adaptive global shallow-water model is proposed on cubed-sphere grid using the multimoment finite volume scheme and the Berger–Oliger adaptive mesh refinement (AMR) algorithm that was originally designed for a Cartesian grid. On each patch of ...

Chungang Chen; Feng Xiao; Xingliang Li

2011-02-01T23:59:59.000Z

73

Petascale Adaptive Computational Fluid Dynamics | Argonne Leadership  

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

Petascale Adaptive Computational Fluid Dynamics Petascale Adaptive Computational Fluid Dynamics PI Name: Kenneth Jansen PI Email: jansen@rpi.edu Institution: Rensselaer Polytechnic Institute The specific aim of this request for resources is to examine scalability and robustness of our code on BG/P. We have confirmed that, during the flow solve phase, our CFD flow solver does exhibit perfect strong scaling to the full 32k cores on our local machine (CCNI-BG/L at RPI) but this will be our first access to BG/P. We are also eager to study the performance of the adaptive phase of our code. Some aspects have scaled well on BG/L (e.g., refinement has produced adaptive meshes that take a 17 million element mesh and perform local adaptivity on 16k cores to match a requested size field to produce a mesh exceeding 1 billion elements) but other aspects (e.g.,

74

An interoperable, data-structure-neutral component for mesh query and manipulation.  

Science Conference Proceedings (OSTI)

Much of the effort required to create a new simulation code goes into developing infrastructure for mesh data manipulation, adaptive refinement, design optimization, and so forth. This infrastructure is an obvious target for code reuse, except that implementations of these functionalities are typically tied to specific data structures. In this article, we describe a software component---an abstract data model and programming interface---designed to provide low-level mesh query and manipulation support for meshing and solution algorithms. The component's data model provides a data abstraction, completely hiding all details of how mesh data is stored, while its interface defines how applications can interact with that data. Because the component has been carefully designed to be general purpose and efficient, it provides a practical platform for implementing high-level mesh operations independently of the underlying mesh data structures. After describing the data model and interface, we provide several usage examples, each of which has been used successfully with multiple implementations of the interface functionality. The overhead due to accessing mesh data through the interface rather than directly accessing the underlying mesh data is shown to be acceptably small.

Ollivier-Gooch, C.; Diachin, L.; Shephard, M. S.; Tautges, T.; Kraftcheck, J.; Leung, V.; Luo, X.; Miller, M. (Mathematics and Computer Science); (Univ. of British Columbia); (LLNL); (Rensselaer Polytechnic Inst.); (Univ. of Wisconsin); (SNL); (LLNL)

2010-01-01T23:59:59.000Z

75

Block-Structured Adaptive Grids on the Sphere: Advection Experiments  

Science Conference Proceedings (OSTI)

A spherical 2D adaptive mesh refinement (AMR) technique is applied to the so-called Lin–Rood advection algorithm, which is built upon a conservative and oscillation-free finite-volume discretization in flux form. The AMR design is based on two ...

Christiane Jablonowski; Michael Herzog; Joyce E. Penner; Robert C. Oehmke; Quentin F. Stout; Bram van Leer; Kenneth G. Powell

2006-12-01T23:59:59.000Z

76

Mesh Dashboard  

Science Conference Proceedings (OSTI)

... [22] In this context, "energy" means the effective energy functional used for mesh optimization, and has nothing to do with the elastic energy of the ...

2013-08-23T23:59:59.000Z

77

Rapid gravity and gravity gradiometry terrain correction via adaptive quadtree mesh discretization Kristofer Davis, M. Andy Kass, and Yaoguo Li, Center for Gravity, Electrical and Magnetic Studies, Colorado School  

E-Print Network (OSTI)

Rapid gravity and gravity gradiometry terrain correction via adaptive quadtree mesh discretization Kristofer Davis, M. Andy Kass, and Yaoguo Li, Center for Gravity, Electrical and Magnetic Studies, Colorado School of Mines SUMMARY We present a method for modeling the terrain response in gravity and gravity

78

Curved mesh generation and mesh refinement using Lagrangian solid mechanics  

E-Print Network (OSTI)

Nonlinear continuum mechanics for ?nite element analysis,nement using Lagrangian Solid Mechanics Per-Olof Persson ?methods for computational mechanics has been emphasized in

Persson, P.-O.

2009-01-01T23:59:59.000Z

79

An HPC component for parallel, heterogeneous, and dynamic unstructured meshes  

Science Conference Proceedings (OSTI)

Multi-physics HPC applications with mixed discretization schemes, adaptive unstructured meshes, and parallel distributed data sets have inherent complexity that must be managed. Design concepts embedded in the mesh data structures will either segregate ... Keywords: adaptivity, data structure, multi-physics, parallel, unstructured mesh

H. Carter Edwards

2007-10-01T23:59:59.000Z

80

A Comparison of Two Shallow-Water Models with Nonconforming Adaptive Grids  

Science Conference Proceedings (OSTI)

In an effort to study the applicability of adaptive mesh refinement (AMR) techniques to atmospheric models, an interpolation-based spectral element shallow-water model on a cubed-sphere grid is compared to a block-structured finite-volume method ...

Amik St-Cyr; Christiane Jablonowski; John M. Dennis; Henry M. Tufo; Stephen J. Thomas

2008-06-01T23:59:59.000Z

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


81

A unified mathematical framework and an adaptive numerical method for fluid-structure interaction with rigid, deforming, and elastic bodies  

Science Conference Proceedings (OSTI)

Many problems of interest in biological fluid mechanics involve interactions between fluids and solids that require the coupled solution of momentum equations for both the fluid and the solid. In this work, we develop a mathematical framework and an ... Keywords: Adaptive mesh refinement, Distributed Lagrange multipliers, Fluid-structure interaction, Free swimming, Immersed boundary method, Incompressible Navier-Stokes equations

Amneet Pal Singh Bhalla, Rahul Bale, Boyce E. Griffith, Neelesh A. Patankar

2013-10-01T23:59:59.000Z

82

An Adaptive Local Grid Refinement and Peak/Valley Capture Algorithm to Solve Nonlinear Transport Problems with Moving Sharp-Fronts  

Science Conference Proceedings (OSTI)

Highly nonlinear advection-dispersion-reaction equations govern numerous transport phenomena. Robust, accurate, and efficient algorithms to solve these equations hold the key to the success of applying numerical models to field problems. This paper presents the development and verification of a computational algorithm to approximate the highly nonlinear transport equations of reactive chemical transport and multiphase flow. The algorithm was developed based on the Lagrangian-Eulerian decoupling method with an adaptive ZOOMing and Peak/valley Capture (LEZOOMPC) scheme. It consists of both backward and forward node tracking, rough element determination, peak/valley capturing, and adaptive local grid refinement. A second-order tracking was implemented to accurately and efficiently track all fictitious particles. Shanks method was introduced to deal with slowly converging case. The accuracy and efficiency of the algorithm were verified with the Burger equation for a variety of cases. The robustness of the algorithm to achieve convergent solutions was demonstrated by highly nonlinear reactive contaminant transport and multiphase flow problems.

Zhang, Fan [ORNL; Jiang, L. [University of Texas, Arlington; Yeh, Gour-Tsyh [University of Central Florida, Orlando; Parker, Jack C [ORNL

2008-01-01T23:59:59.000Z

83

Goal-Oriented Adaptivity and Multilevel Preconditioning for the Poisson-Boltzmann Equation  

E-Print Network (OSTI)

In this article, we develop goal-oriented error indicators to drive adaptive refinement algorithms for the Poisson-Boltzmann equation. Empirical results for the solvation free energy linear functional demonstrate that goal-oriented indicators are not sufficient on their own to lead to a superior refinement algorithm. To remedy this, we propose a problem-specific marking strategy using the solvation free energy computed from the solution of the linear regularized Poisson-Boltzmann equation. The convergence of the solvation free energy using this marking strategy, combined with goal-oriented refinement, compares favorably to adaptive methods using an energy-based error indicator. Due to the use of adaptive mesh refinement, it is critical to use multilevel preconditioning in order to maintain optimal computational complexity. We use variants of the classical multigrid method, which can be viewed as generalizations of the hierarchical basis multigrid and Bramble-Pasciak-Xu (BPX) preconditioners.

Burak Aksoylu; Stephen Bond; Eric Cyr; Michael Holst

2011-09-19T23:59:59.000Z

84

Refining Cups  

Science Conference Proceedings (OSTI)

For use with AOCS Official Method Ca-9a 52. Refining Cups Lab Supplies Lab Supplies Series Methods Refining Cup - 960 mL For use with AOCS Official Method Ca-9a 52. E5323FF88E60507DAA8DE2F0F507CB97 014 1878

85

Guaranteed-quality anisotropic mesh generation for domains with curved boundaries  

Science Conference Proceedings (OSTI)

Anisotropic mesh generation is important for interpolation and numerical modeling. Recently, Labelle and Shewchuk proposed a two-dimensional guaranteed-quality anisotropic mesh generation algorithm called a Voronoi refinement algorithm. This algorithm ... Keywords: Anisotropic Voronoi diagram, Anisotropic mesh generation, Curved boundaries, Guaranteed-quality

Yusuke Yokosuka; Keiko Imai

2009-05-01T23:59:59.000Z

86

A Direct Method for Constructing Refined Regions in Unstructured Conforming Triangular–Hexagonal Computational Grids: Application to OLAM  

Science Conference Proceedings (OSTI)

A scheme is presented for constructing refined regions of 2D unstructured computational meshes composed of triangular cells. The method preserves the conforming property of the original unrefined mesh and does not produce hanging nodes. The ...

Robert L. Walko; Roni Avissar

2011-12-01T23:59:59.000Z

87

Worldwide refining  

Science Conference Proceedings (OSTI)

Data are presented on refining capacity by country and by company within each country. Capacity data are divided into the following processes: vacuum distillation, thermal operations, catalytic cracking, catalytic reforming, catalytic hydrocracking, catalytic hydrorefining, and catalytic hydrotreating. Production capacity is divided into: alkylation/polymerization/dimerization; aromatics/isomerization; lubricants; oxygenates; hydrogen; petroleum coke; and asphalts.

NONE

1995-12-18T23:59:59.000Z

88

Adaptive Implicit Non-Equilibrium Radiation Diffusion  

SciTech Connect

We describe methods for accurate and efficient long term time integra- tion of non-equilibrium radiation diffusion systems: implicit time integration for effi- cient long term time integration of stiff multiphysics systems, local control theory based step size control to minimize the required global number of time steps while control- ling accuracy, dynamic 3D adaptive mesh refinement (AMR) to minimize memory and computational costs, Jacobian Free Newton-Krylov methods on AMR grids for efficient nonlinear solution, and optimal multilevel preconditioner components that provide level independent solver convergence.

Philip, Bobby [ORNL; Wang, Zhen [ORNL; Berrill, Mark A [ORNL; Rodriguez Rodriguez, Manuel [ORNL; Pernice, Michael [Idaho National Laboratory (INL)

2013-01-01T23:59:59.000Z

89

Well-centered meshing.  

E-Print Network (OSTI)

??A well-centered simplex is a simplex whose circumcenter lies in its interior, and a well-centered mesh is a simplicial mesh in which every simplex is… (more)

Vanderzee, Evan B.

2010-01-01T23:59:59.000Z

90

Grain Refining Aluminum Alloys  

Science Conference Proceedings (OSTI)

He has had responsibility within Alcoa for optimizing grain refining and alloying ... of grain refinement; Methods of grain refining; Attributes of chemical inoculants ...

91

Modeling Mine Mesh Networks  

Science Conference Proceedings (OSTI)

... is required beyond the powered UHF mesh ... OPNET simulation tool will be network performance metrics ... throughput, delay, and packet loss ratio for ...

2010-10-05T23:59:59.000Z

92

Mine Mesh Networks  

Science Conference Proceedings (OSTI)

... and analyzed underground measurements of MF signal strength in the NIOSH Pittsburgh Research Laboratory Safety Research Coal Mine to refine ...

2010-10-05T23:59:59.000Z

93

Refining and Characterization  

Science Conference Proceedings (OSTI)

Mar 13, 2012 ... Solar Cell Silicon: Refining and Characterization .... Silicon PV Wafers: Correlation of Mechanical Properties and Crack Propagation with ...

94

Optimal placement of mesh points in wireless mesh networks  

Science Conference Proceedings (OSTI)

A strategic placement of mesh points (MPs) in a Wireless Mesh Network (WMN) is essential to maximize the throughput of the network. In this paper, we address the problem of MPs placement for throughput optimization in WMN with consideration of routing ... Keywords: gateway placement, throughput optimization, wireless mesh network

Suk Yu Hui; Kai Hau Yeung; Kin Yeung Wong

2008-05-01T23:59:59.000Z

95

Introducing backward refinement into B  

Science Conference Proceedings (OSTI)

The B Method exploits a direct first-order wp predicate-transformer formulation of downward simulation to generate its proof obligations for a refinement, so B's notion of refinement is restricted to that of forward refinement. Therefore some refinements ...

Steve Dunne

2003-06-01T23:59:59.000Z

96

802.16 mesh networking  

E-Print Network (OSTI)

We present an overview of the 802.16 mesh protocol with a specific focus on the networking aspects of the protocol. We first review the 802.16 mesh Time Division Multiple Access (TDMA) technology, including state of the art research on scheduling algorithms required by the technology. We then propose an addressing assignment for the 802.16 mesh networks that allows the network layer to take advantage of Qualityof-Service (QoS) provided by the 802.16 mesh protocol. Our addressing scheme allows network layer management of QoS at the edge of the network, thus allowing for simplicity in design of mesh routers. We also overview the security infrastructure of 802.16 mesh networks and their flaws. We propose an end-to-end security scheme that simplifies the design of 802.16 mesh routers. 1

Petar Djukic; Shahrokh Valaee

2007-01-01T23:59:59.000Z

97

SAMRAI V3.1  

Energy Science and Technology Software Center (OSTI)

001825MLTPL01 Structured Adaptive Mesh Refinement Application Infrastructure  https://computation.llnl.gov/casc/samrai 

98

Biocatalysis in Oil Refining  

SciTech Connect

Biocatalysis in Oil Refining focuses on petroleum refining bioprocesses, establishing a connection between science and technology. The micro organisms and biomolecules examined for biocatalytic purposes for oil refining processes are thoroughly detailed. Terminology used by biologists, chemists and engineers is brought into a common language, aiding the understanding of complex biological-chemical-engineering issues. Problems to be addressed by the future R&D activities and by new technologies are described and summarized in the last chapter.

Borole, Abhijeet P [ORNL; Ramirez-Corredores, M. M. [BP Global Fuels Technology

2007-01-01T23:59:59.000Z

99

Refining of shale oil  

DOE Green Energy (OSTI)

The refining of shale oil is reviewed to assess the current state-of-the-art, especially as to the avaiability of technology suitable for operation on a commercial scale. Oil shale retorting processes as they affect the quality of the crude shale oil for refining, exploratory research on the character and refining of shale oil, and other published refining background leading to the present status are discussed. The initial refining of shale oil requires the removal of a large concentration of nitrogen, an added step not required for typical petroleum crude oils, and recently published estimates show that the total cost of refining will be high. Specific technoloy is reported by industry to be technically proven and available for commercial-scale refining. Although the refining will be more costly than that of petroleum, the viability of a shale oil industry will also be affected greatly by the technology and costs of producing the crude shale oil, environmental costs, and future price and tax treatment, and these are outside the scope of this study of refining.

Lanning, W.C.

1978-05-01T23:59:59.000Z

100

Optimal refinement of rule bases  

Science Conference Proceedings (OSTI)

This article presents a formal analysis of the rule refinement selection problem. There is no satisfactory methodical standard for the optimal refinement of rule bases. Current refinement systems select the best overall rule base refinements out of a ... Keywords: Rule base validation, complex gain calculation, conflicting and alternative rule refinements, evaluation of safety-critical knowledge bases, optimal refinement selection, rule refinement classes, subsumption and synergy

Hans-Werner Kelbassa

2004-08-01T23:59:59.000Z

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


101

Final Report: Symposium on Adaptive Methods for Partial Differential Equations  

SciTech Connect

Complex physical phenomena often include features that span a wide range of spatial and temporal scales. Accurate simulation of such phenomena can be difficult to obtain, and computations that are under-resolved can even exhibit spurious features. While it is possible to resolve small scale features by increasing the number of grid points, global grid refinement can quickly lead to problems that are intractable, even on the largest available computing facilities. These constraints are particularly severe for three dimensional problems that involve complex physics. One way to achieve the needed resolution is to refine the computational mesh locally, in only those regions where enhanced resolution is required. Adaptive solution methods concentrate computational effort in regions where it is most needed. These methods have been successfully applied to a wide variety of problems in computational science and engineering. Adaptive methods can be difficult to implement, prompting the development of tools and environments to facilitate their use. To ensure that the results of their efforts are useful, algorithm and tool developers must maintain close communication with application specialists. Conversely it remains difficult for application specialists who are unfamiliar with the methods to evaluate the trade-offs between the benefits of enhanced local resolution and the effort needed to implement an adaptive solution method.

Pernice, Michael; Johnson, Christopher R.; Smith, Philip J.; Fogelson, Aaron

1998-12-08T23:59:59.000Z

102

Adaptive nearest-nodes finite element method guided by gradient of linear strain energy density  

Science Conference Proceedings (OSTI)

In this paper, an adaptive finite element method is formulated based on the newly developed nearest-nodes finite element method (NN-FEM). In the adaptive NN-FEM, mesh modification is guided by the gradient of strain energy density, i.e., a larger gradient ... Keywords: Gradient of strain energy density, Mesh intensity, Mesh modification operator, Nearest-nodes finite element method

Yunhua Luo

2009-10-01T23:59:59.000Z

103

A Collection of 2D Elliptic Problems for Testing Adaptive Grid ...  

Science Conference Proceedings (OSTI)

... Grid Refinement Algorithms $ ... Keywords: adaptive grid refinement, standard test problems, benchmarking 2010 MSC: 65N50, 65N30 1. Introduction ...

2013-06-20T23:59:59.000Z

104

Streaming Compression of Hexahedral Meshes  

Science Conference Proceedings (OSTI)

We describe a method for streaming compression of hexahedral meshes. Given an interleaved stream of vertices and hexahedral our coder incrementally compresses the mesh in the presented order. Our coder is extremely memory efficient when the input stream documents when vertices are referenced for the last time (i.e. when it contains topological finalization tags). Our coder then continuously releases and reuses data structures that no longer contribute to compressing the remainder of the stream. This means in practice that our coder has only a small fraction of the whole mesh in memory at any time. We can therefore compress very large meshes - even meshes that do not file in memory. Compared to traditional, non-streaming approaches that load the entire mesh and globally reorder it during compression, our algorithm trades a less compact compressed representation for significant gains in speed, memory, and I/O efficiency. For example, on the 456k hexahedra 'blade' mesh, our coder is twice as fast and uses 88 times less memory (only 3.1 MB) with the compressed file increasing about 3% in size. We also present the first scheme for predictive compression of properties associated with hexahedral cells.

Isenburg, M; Courbet, C

2010-02-03T23:59:59.000Z

105

Linear rotation-invariant coordinates for meshes  

Science Conference Proceedings (OSTI)

We introduce a rigid motion invariant mesh representation based on discrete forms defined on the mesh. The reconstruction of mesh geometry from this representation requires solving two sparse linear systems that arise from the discrete forms: the first ... Keywords: local frames, mesh editing, rigid-motion invariant shape representation, shape blending

Yaron Lipman; Olga Sorkine; David Levin; Daniel Cohen-Or

2005-07-01T23:59:59.000Z

106

Battery-aware scheduling inwireless mesh networks  

Science Conference Proceedings (OSTI)

Wireless mesh networks recently emerge as a flexible, low-cost and multipurpose networking platform with wired infrastructure connected to the Internet. A critical issue in mesh networks is to maintain network activities for a long lifetime with high ... Keywords: battery models, battery-awareness, energy efficiency, lifetime optimization, mesh routers, power scheduling, wireless mesh networks

Chi Ma; Zhenghao Zhang; Yuanyuan Yang

2008-04-01T23:59:59.000Z

107

Adaptive Urban Dispersion Integrated Model  

DOE Green Energy (OSTI)

Numerical simulations represent a unique predictive tool for understanding the three-dimensional flow fields and associated concentration distributions from contaminant releases in complex urban settings (Britter and Hanna 2003). Utilization of the most accurate urban models, based on fully three-dimensional computational fluid dynamics (CFD) that solve the Navier-Stokes equations with incorporated turbulence models, presents many challenges. We address two in this work; first, a fast but accurate way to incorporate the complex urban terrain, buildings, and other structures to enforce proper boundary conditions in the flow solution; second, ways to achieve a level of computational efficiency that allows the models to be run in an automated fashion such that they may be used for emergency response and event reconstruction applications. We have developed a new integrated urban dispersion modeling capability based on FEM3MP (Gresho and Chan 1998, Chan and Stevens 2000), a CFD model from Lawrence Livermore National Lab. The integrated capability incorporates fast embedded boundary mesh generation for geometrically complex problems and full three-dimensional Cartesian adaptive mesh refinement (AMR). Parallel AMR and embedded boundary gridding support are provided through the SAMRAI library (Wissink et al. 2001, Hornung and Kohn 2002). Embedded boundary mesh generation has been demonstrated to be an automatic, fast, and efficient approach for problem setup. It has been used for a variety of geometrically complex applications, including urban applications (Pullen et al. 2005). The key technology we introduce in this work is the application of AMR, which allows the application of high-resolution modeling to certain important features, such as individual buildings and high-resolution terrain (including important vegetative and land-use features). It also allows the urban scale model to be readily interfaced with coarser resolution meso or regional scale models. This talk will discuss details of the approach and present results for some example calculations performed in Manhattan in support of the DHS Urban Dispersion Program (UDP) using some of the tools developed as part of this new capability.

Wissink, A; Chand, K; Kosovic, B; Chan, S; Berger, M; Chow, F K

2005-11-03T23:59:59.000Z

108

Quantifying And Managing The Influence Of Maintenance Actions On The Survivability Of Mesh-Restorable Networks  

E-Print Network (OSTI)

of "roll to protection" in rings. The basic methods can be adapted for other maintenance models or models of the restoration process or adapted to handle multiple maintenance scenarios. The work is aimed at understanding and managing the effects of maintenance in a mesh-restorable network and ultimately providing new operational and design capabilities for future mesh-based network planning and operations systems. I. Motivation and Background One of the motivations for mesh-restorable networking is the greater capacity efficiency of mesh networks relative to ring-based transport networks. The capacity efficiency comes from the more direct routing of working paths, the need for less spare capacity for restoration, and the avoidance of "stranded capacity" effects in rings where one or more ring spans may exhaust while other spans of the ring have valuable but unusable remaining working capacity. Of course capacity efficiency is not the only consideration in a choice of n

Wayne D. Grover; Matthieu Clouqueur; Thuthuy Bach

2001-01-01T23:59:59.000Z

109

Modeling planar 3-valence meshes  

E-Print Network (OSTI)

In architectural and sculptural practice, the eventual goal is constructing the shapes that have been designed. Due to fabrication considerations, shapes with planar faces are in demand for these practices. In this thesis, a novel computational modeling approach to design constructible shapes is introduced. This method guarantees that the resulting shapes are planar meshes with 3-valence vertices, which can always be physically constructed using planar or developable materials such as glass, sheet metal or plywood. The method introduced is inspired by the traditional sculpture and is based on the idea of carving a mesh by using slicing planes. The process of determining the slicing planes can either be interactive or automated. A framework is developed which allows user to sculpt shapes by using the in- teractive and automated processes. The framework allows user to cut a source mesh based on its edges, faces or vertices. The user can sculpt various kinds of developable surfaces by cutting the parallel edges of the mesh. The user can also introduce in- teresting conical patterns by cutting dierent vertex, edge, face combinations of the mesh.

Gonen, Ozgur

2007-12-01T23:59:59.000Z

110

REFINING FLUORINATED COMPOUNDS  

DOE Patents (OSTI)

This invention relates to the method of refining a liquid perfluorinated hydrocarbon oil containing fluorocarbons from 12 to 28 carbon atoms per molecule by distilling between 150 deg C and 300 deg C at 10 mm Hg absolute pressure. The perfluorinated oil is washed with a chlorinated lower aliphatic hydrocarbon, which mairtains a separate liquid phase when mixed with the oil. Impurities detrimental to the stability of the oil are extracted by the chlorinated lower aliphatic hydrocarbon. (AEC)

Linch, A.L.

1963-01-01T23:59:59.000Z

111

Developing security protocols by refinement  

Science Conference Proceedings (OSTI)

We propose a development method for security protocols based on stepwise refinement. Our refinement strategy guides the transformation of abstract security goals into protocols that are secure when operating over an insecure channel controlled by a Dolev-Yao-style ... Keywords: entity authentication, formal development, key establishment, security protocols, stepwise refinement

Christoph Sprenger; David Basin

2010-10-01T23:59:59.000Z

112

Interactive graphical tools for three-dimensional mesh redistribution  

Science Conference Proceedings (OSTI)

Three-dimensional meshes modeling nonlinear problems such as sheet metal forming, metal forging, heat transfer during welding, the propagation of microwaves through gases, and automobile crashes require highly refined meshes in local areas to accurately represent areas of high curvature, stress, and strain. These locally refined areas develop late in the simulation and/or move during the course of the simulation, thus making it difficult to predict their exact location. This thesis is a systematic study of new tools scientists can use with redistribution algorithms to enhance the solution results and reduce the time to build, solve, and analyze nonlinear finite element problems. Participatory design techniques including Contextual Inquiry and Design were used to study and analyze the process of solving such problems. This study and analysis led to the in-depth understanding of the types of interactions performed by FEM scientists. Based on this understanding, a prototype tool was designed to support these interactions. Scientists participated in evaluating the design as well as the implementation of the prototype tool. The study, analysis, prototype tool design, and the results of the evaluation of the prototype tool are described in this thesis.

Dobbs, L.A.

1996-03-01T23:59:59.000Z

113

Minimally refined biomass fuel  

DOE Patents (OSTI)

A minimally refined fluid composition, suitable as a fuel mixture and derived from biomass material, is comprised of one or more water-soluble carbohydrates such as sucrose, one or more alcohols having less than four carbons, and water. The carbohydrate provides the fuel source; water solubilizes the carbohydrates; and the alcohol aids in the combustion of the carbohydrate and reduces the vicosity of the carbohydrate/water solution. Because less energy is required to obtain the carbohydrate from the raw biomass than alcohol, an overall energy savings is realized compared to fuels employing alcohol as the primary fuel.

Pearson, Richard K. (Pleasanton, CA); Hirschfeld, Tomas B. (Livermore, CA)

1984-01-01T23:59:59.000Z

114

Fabrication and Characterization of Reticulated, Porous Mesh ...  

Science Conference Proceedings (OSTI)

Feb 1, 2010 ... Fabrication and Characterization of Reticulated, Porous Mesh Arrays and Foams for Aerospace Applications by Additive Manufacturing Using ...

115

Real-Time Deployment of Mesh Networks  

Science Conference Proceedings (OSTI)

... Related Efforts. DARPA LANdroids program. Publications. MR Souryal, A. Wapf, N. Moayeri, Rapidly-Deployable Mesh Network Testbed; ...

2013-07-08T23:59:59.000Z

116

Fast mesh segmentation using random walks  

Science Conference Proceedings (OSTI)

3D mesh models are now widely available for use in various applications. The demand for automatic model analysis and understanding is ever increasing. Mesh segmentation is an important step towards model understanding, and acts as a useful tool for different ... Keywords: interactive, mesh segmentation, random walks

Yu-Kun Lai; Shi-Min Hu; Ralph R. Martin; Paul L. Rosin

2008-06-01T23:59:59.000Z

117

Weekly Refiner Net Production  

U.S. Energy Information Administration (EIA) Indexed Site

Refiner Net Production Refiner Net Production (Thousand Barrels per Day) Period: Weekly 4-Week Average Download Series History Download Series History Definitions, Sources & Notes Definitions, Sources & Notes Product/Region 11/08/13 11/15/13 11/22/13 11/29/13 12/06/13 12/13/13 View History Finished Motor Gasoline 2,168 2,300 2,336 2,359 2,462 2,368 2010-2013 East Coast (PADD 1) 54 53 52 67 71 67 2010-2013 Midwest (PADD 2) 696 745 722 711 798 790 2010-2013 Gulf Coast (PADD 3) 891 916 1,010 1,053 1,011 1,021 2010-2013 Rocky Mountain (PADD 4) 260 248 245 232 279 235 2010-2013 West Coast (PADD 5) 268 338 308 296 302 255 2010-2013 Reformulated 50 49 49 49 48 49 2010-2013 Blended with Ethanol 50 49 49 49 48 49 2010-2013 Other

118

Refines Efficiency Improvement  

Science Conference Proceedings (OSTI)

Refinery processes that convert heavy oils to lighter distillate fuels require heating for distillation, hydrogen addition or carbon rejection (coking). Efficiency is limited by the formation of insoluble carbon-rich coke deposits. Heat exchangers and other refinery units must be shut down for mechanical coke removal, resulting in a significant loss of output and revenue. When a residuum is heated above the temperature at which pyrolysis occurs (340 C, 650 F), there is typically an induction period before coke formation begins (Magaril and Aksenova 1968, Wiehe 1993). To avoid fouling, refiners often stop heating a residuum before coke formation begins, using arbitrary criteria. In many cases, this heating is stopped sooner than need be, resulting in less than maximum product yield. Western Research Institute (WRI) has developed innovative Coking Index concepts (patent pending) which can be used for process control by refiners to heat residua to the threshold, but not beyond the point at which coke formation begins when petroleum residua materials are heated at pyrolysis temperatures (Schabron et al. 2001). The development of this universal predictor solves a long standing problem in petroleum refining. These Coking Indexes have great potential value in improving the efficiency of distillation processes. The Coking Indexes were found to apply to residua in a universal manner, and the theoretical basis for the indexes has been established (Schabron et al. 2001a, 2001b, 2001c). For the first time, a few simple measurements indicates how close undesired coke formation is on the coke formation induction time line. The Coking Indexes can lead to new process controls that can improve refinery distillation efficiency by several percentage points. Petroleum residua consist of an ordered continuum of solvated polar materials usually referred to as asphaltenes dispersed in a lower polarity solvent phase held together by intermediate polarity materials usually referred to as resins. The Coking Indexes focus on the amount of these intermediate polarity species since coke formation begins when these are depleted. Currently the Coking Indexes are determined by either titration or solubility measurements which must be performed in a laboratory. In the current work, various spectral, microscopic, and thermal techniques possibly leading to on-line analysis were explored for measuring the Coking Indexes.

WRI

2002-05-15T23:59:59.000Z

119

Refiner Wholesale Price ...........................  

Gasoline and Diesel Fuel Update (EIA)

Prices (cents per gallon) Prices (cents per gallon) Refiner Wholesale Price ........................... 297 299 302 275 289 290 288 262 275 289 280 257 293 282 276 Gasoline Regular Grade Retail Prices Including Taxes PADD 1 .................................................... 363 366 364 355 361 350 355 331 341 355 347 327 362 349 343 PADD 2 .................................................... 355 366 369 340 350 368 352 318 334 355 346 318 357 347 338 PADD 3 .................................................... 346 353 345 326 339 336 337 307 323 341 329 305 343 330 325 PADD 4 .................................................... 322 374 358 348 323 361 362 326 322 351 348 322 351 344 337 PADD 5 .................................................... 390 413 390 384 382 390 385 355 362 384 379 356 394 378 371 U.S. Average ........................................

120

SHARP/PRONGHORN Interoperability: Mesh Generation  

SciTech Connect

Progress toward collaboration between the SHARP and MOOSE computational frameworks has been demonstrated through sharing of mesh generation and ensuring mesh compatibility of both tools with MeshKit. MeshKit was used to build a three-dimensional, full-core very high temperature reactor (VHTR) reactor geometry with 120-degree symmetry, which was used to solve a neutron diffusion critical eigenvalue problem in PRONGHORN. PRONGHORN is an application of MOOSE that is capable of solving coupled neutron diffusion, heat conduction, and homogenized flow problems. The results were compared to a solution found on a 120-degree, reflected, three-dimensional VHTR mesh geometry generated by PRONGHORN. The ability to exchange compatible mesh geometries between the two codes is instrumental for future collaboration and interoperability. The results were found to be in good agreement between the two meshes, thus demonstrating the compatibility of the SHARP and MOOSE frameworks. This outcome makes future collaboration possible.

Avery Bingham; Javier Ortensi

2012-09-01T23:59:59.000Z

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


121

Carbon Emissions: Petroleum Refining Industry  

U.S. Energy Information Administration (EIA)

Energy-Related Carbon Emissions for the Petroleum and Coal Products Industry, 1994. Petroleum refining is by far the largest component of the petroleum and ...

122

Coupled Mesh Lagrangian/ALE Modeling:  

National Nuclear Security Administration (NNSA)

Coupled Mesh Lagrangian/ALE Modeling: Coupled Mesh Lagrangian/ALE Modeling: Opportunities and Challenges A. C. Robinson, * J. E. Bishop*, D. M. Hensinger, * T. E. Voth * M. K. Wong * * Sandia National Laboratories, New Mexico, 87185 We describe two methods for coupled mesh Lagrangian/ALE modeling where one mesh is treated as a Lagrangian mesh while the other is ALE. Lagrangian contact modeling is implemented in the first method to couple the two meshes. In the second method an overlapping grid algorithm that requires mapping of the information from one grid to another has been implemented. We review current experience with these two technologies. Introduction Lagrangian modeling is often preferred whenever the kinematics of the continuum flow permit because of its ability to precisely model discrete features which may be

123

Collaboration Topics - Meshing | National Nuclear Security Administrat...  

National Nuclear Security Administration (NNSA)

CAD support for meshing and geometry simplification are also within the scope of this joint work. Accomplishments We have established a working technical collaboration for the...

124

Collaboration Topics - Meshing | National Nuclear Security Administrat...  

National Nuclear Security Administration (NNSA)

& Technology Programs > Office of Advanced Simulation and Computing and Institutional R&D Programs > NNSACEA Cooperation in Computer Science > Collaboration Topics - Meshing...

125

An adaptive projection method for the modeling of unsteady, low-Mach number combustion  

SciTech Connect

In this paper the authors present an adaptive projection method for modeling unsteady, low-Mach reacting flow in an unconfined region. The equations they solve are based on a model for low-Mach number combustion that consists of the evolution equations for density, species concentrations, enthalpy, and momentum coupled with a constraint on the divergence of the flow. The algorithm is based on a projection methodology in which they first advance the evolution equations and then solve an elliptic equation to enforce the divergence constraint. The adaptive mesh refinement (AMR) scheme uses a time-varying, hierarchical grid structure composed of uniform rectangular grids of varying resolution. The integration scheme on the grid hierarchy is a recursive procedure in which a coarse grid is advanced, fine grids are advanced multiple steps to reach the same time as the coarse grid, and the coarse and the fine grids are synchronized. The method is valid for multiple grids on each level and multiple levels of refinement. The method is currently implemented for laminar, axisymmetric flames with a reduced kinetics mechanism and a Lewis number of unity. Two methane-air flames, one steady and the other flickering, are presented as numerical examples.

Pember, R.B.; Howell, L.H.; Bell, J.B.; Colella, P.; Crutchfield, W.Y. [Lawrence Berkeley National Lab., CA (United States); Fiveland, W.A.; Jesse, J.P. [Babcock and Wilcox, Alliance, OH (United States)

1997-10-01T23:59:59.000Z

126

Parallel Space Decomposition of the Mesh Adaptive Direct Search ...  

E-Print Network (OSTI)

1-0302, the Boeing Company, ExxonMobil Upstream Research Company, and the first and third authors were supported by the Consortium for Research and ...

127

The mesh adaptive direct search algorithm with treed Gaussian ...  

E-Print Network (OSTI)

May 24, 2013 ... for styrene production; and one from contaminant cleanup and hydrology. In all .... improvement and exploration oriented statistics. The poll ...

128

Fault tolerance using lower fidelity data in adaptive mesh applications  

Science Conference Proceedings (OSTI)

Many high performance scientific simulation codes use checkpointing for multiple reasons. In addition to having the flexibility to complete the simulation in multiple job submissions, it has also provided an adequate recovery mechanism up to the current ... Keywords: AMR, fault tolerance, flash

Anshu Dubey; Prateeti Mohapatra; Klaus Weide

2013-06-01T23:59:59.000Z

129

Multilevel Diffusion Schemes for Repartitioning of Adaptive Meshes #  

E-Print Network (OSTI)

weight is greater than the average partition weight times 1 + #. Likewise, a partition is underbalanced partition are simply swapped into one or more underbalanced partitions in order to bring these partitions up underbalanced partitions and to eventually reach balance, just as in the analogous case, uneven temperatures

Kumar, Vipin

130

Repartitioning of Adaptive Meshes: Experiments with Multilevel Di usion ?  

E-Print Network (OSTI)

are simply swapped into one or more underbalanced partitions in order to bring these par- titions up partitions to underbalanced partitions and to eventually reach balance, just as in the analogous case, uneven overbalanced partitions does not make use of the global information about the location of underbalanced par

Karypis, George

131

USE OF QUADRATIC MODELS WITH MESH ADAPTIVE DIRECT ...  

E-Print Network (OSTI)

Mar 6, 2011 ... The version with the models uses both the model search and the model ordering strategies, a radius factor ? set to 2, no maintenance of well ...

132

Preservation of probabilistic information flow under refinement  

Science Conference Proceedings (OSTI)

Information flow properties, which describe confidentiality requirements, are not generally preserved under behavior refinement. This article describes a formal framework for refinement relations between nondeterministic probabilistic processes that ... Keywords: CSP, Confidentiality, Information flow property, Information theory, Process calculus, Refinement, Security

Thomas Santen

2008-02-01T23:59:59.000Z

133

Nucleic Acid Standards - Refinement Parameters  

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

Refinement Parameters Refinement Parameters The DNA/RNA topology and parameter files for X-PLOR are shown below. These were tested with DNA structures and with protein-DNA complexes. X-PLOR topology file X-PLOR parameter files: X-PLOR parameter file For the refinement of high resolution structures (< 1.7 Angstroms) the parameter file with distinct bond distances and bond angles for both C2'-endo and C3'-endo conformations should be considered: X-PLOR parameter file for high resolution structures "New Parameters for the Refinement of Nucleic Acid Containing Structures." Gary Parkinson, Jaroslav Vojtechovsky, Lester Clowney, Axel Brunger*, and Helen M. Berman. (1996) Acta Cryst. D 52, 57-64 Rutgers University, Department of Chemistry, Piscataway, NJ 08855-0939; *The Howard Hughes Medical Institute and Departments of Molecular and

134

7th International Meshing Roundtable '98  

SciTech Connect

The goal of the 7th International Meshing Roundtable is to bring together researchers and developers from industry, academia, and government labs in a stimulating, open environment for the exchange of technical information related to the meshing process. In the past, the Roundtable has enjoyed significant participation from each of these groups from a wide variety of countries.

Eldred, T.J.

1998-10-01T23:59:59.000Z

135

A generic theorem prover of CSP refinement  

E-Print Network (OSTI)

Abstract. We describe a new tool called Csp-Prover which is an interactive theorem prover dedicated to refinement proofs within the process algebra Csp. It aims specifically at proofs for infinite state systems, which may also involve infinite non-determinism. Semantically, Csp-Prover supports both the theory of complete metric spaces as well as the theory of complete partial orders. Both these theories are implemented for infinite product spaces. Technically, Csp-Prover is based on the theorem prover Isabelle. It provides a deep encoding of Csp. The tool’s architecture follows a generic approach which makes it easy to adapt it for various Csp models besides those studied here: the stable failures model F and the traces model T. 1

Yoshinao Isobe; Markus Roggenbach

2005-01-01T23:59:59.000Z

136

Analysis of Traffic Scheduling Technique for Smart Grid Mesh ...  

Science Conference Proceedings (OSTI)

Analysis of Traffic Scheduling Technique for Smart Grid Mesh Networks ... In this paper, we present a multi-gate mesh network architecture that has ...

2012-01-03T23:59:59.000Z

137

Optimal-time dynamic mesh refinement: preliminary results Umut A. Acar  

E-Print Network (OSTI)

to the input point. This yielding ensures that the input points Toyota Technological Inst., Chicago, IL. umut was at Toyota Technological Inst. 1The spread is defined as the ratio between the diameter of the input space

Hudon, Benoit

138

Zone refining of plutonium metal  

Science Conference Proceedings (OSTI)

The zone refining process was applied to Pu metal containing known amounts of impurities. Rod specimens of plutonium metal were melted into and contained in tantalum boats, each of which was passed horizontally through a three-turn, high-frequency coil in such a manner as to cause a narrow molten zone to pass through the Pu metal rod 10 times. The impurity elements Co, Cr, Fe, Ni, Np, U were found to move in the same direction as the molten zone as predicted by binary phase diagrams. The elements Al, Am, and Ga moved in the opposite direction of the molten zone as predicted by binary phase diagrams. As the impurity alloy was zone refined, {delta}-phase plutonium metal crystals were produced. The first few zone refining passes were more effective than each later pass because an oxide layer formed on the rod surface. There was no clear evidence of better impurity movement at the slower zone refining speed. Also, constant or variable coil power appeared to have no effect on impurity movement during a single run (10 passes). This experiment was the first step to developing a zone refining process for plutonium metal.

Blau, M.S.

1994-08-01T23:59:59.000Z

139

Indiana, Illinois, and Kentucky Refining District Percent ...  

U.S. Energy Information Administration (EIA)

Indiana, Illinois, and Kentucky Refining District Percent Utilization of Refinery Operable Capacity (Percent)

140

Carbon Emissions: Petroleum Refining Industry  

U.S. Energy Information Administration (EIA) Indexed Site

Petroleum Refining Industry Petroleum Refining Industry Carbon Emissions in the Petroleum Refining Industry The Industry at a Glance, 1994 (SIC Code: 2911) Total Energy-Related Emissions: 79.9 million metric tons of carbon (MMTC) -- Pct. of All Manufacturers: 21.5% -- Nonfuel Emissions: 16.5 MMTC Total First Use of Energy: 6,263 trillion Btu -- Pct. of All Manufacturers: 28.9% Nonfuel Use of Energy Sources: 3,110 trillion Btu (49.7%) -- Naphthas and Other Oils: 1,328 trillion Btu -- Asphalt and Road Oil: 1,224 trillion Btu -- Lubricants: 416 trillion Btu Carbon Intensity: 12.75 MMTC per quadrillion Btu Energy Information Administration, "1994 Manufacturing Energy Consumption Survey", "Monthly Refinery Report" for 1994, and Emissions of Greenhouse Gases in the United States 1998.

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


141

Electronic structure of superconductivity refined  

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

Electronic structure of superconductivity refined Electronic structure of superconductivity refined Electronic structure of superconductivity refined A team of physicists propose a new model that expands on a little understood aspect of the electronic structure in high-temperature superconductors. July 10, 2008 Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials. Los Alamos National Laboratory sits on top of a once-remote mesa in northern New Mexico with the Jemez mountains as a backdrop to research and innovation covering multi-disciplines from bioscience, sustainable energy sources, to plasma physics and new materials.

142

Vacuum State/Refiner/Location  

U.S. Energy Information Administration (EIA) Indexed Site

Vacuum Vacuum State/Refiner/Location Barrels per Atmospheric Crude Oil Distillation Capacity Barrels per Operating Idle Operating Idle Downstream Charge Capacity Thermal Cracking Delayed Fluid Coking Visbreaking Other/Gas Calendar Day Stream Day Distillation Coking Oil Table 3. Capacity of Operable Petroleum Refineries by State as of January 1, 2013 (Barrels per Stream Day, Except Where Noted) ......................................................... Alabama 120,100 0 130,000 0 48,000 32,000 0 0 0 Goodway Refining LLC 4,100 0 5,000 0 0 0 0 0 0 ....................................................................................................................................................................................................

143

Are Refiners Entering a Golden Age or a Short Cycle?  

U.S. Energy Information Administration (EIA)

Are Refiners Entering a Golden Age or a Short Cycle? Global Refining Strategies 2007 Barcelona, Spain

144

LR: Compact connectivity representation for triangle meshes  

Science Conference Proceedings (OSTI)

We propose LR (Laced Ring) - a simple data structure for representing the connectivity of manifold triangle meshes. LR provides the option to store on average either 1.08 references per triangle or 26.2 bits per triangle. Its construction, from an input mesh that supports constant-time adjacency queries, has linear space and time complexity, and involves ordering most vertices along a nearly-Hamiltonian cycle. LR is best suited for applications that process meshes with fixed connectivity, as any changes to the connectivity require the data structure to be rebuilt. We provide an implementation of the set of standard random-access, constant-time operators for traversing a mesh, and show that LR often saves both space and traversal time over competing representations.

Gurung, T; Luffel, M; Lindstrom, P; Rossignac, J

2011-01-28T23:59:59.000Z

145

Method for refining contaminated iridium  

DOE Patents (OSTI)

Contaminated iridium is refined by alloying it with an alloying agent selected from the group consisting of manganese and an alloy of manganese and copper, and then dissolving the alloying agent from the formed alloy to provide a purified iridium powder.

Heshmatpour, Bahman (Waltham, MA); Heestand, Richard L. (Oak Ridge, TN)

1983-01-01T23:59:59.000Z

146

Mesh scissoring with minima rule and part salience  

Science Conference Proceedings (OSTI)

This paper presents an intelligent scissoring operator for meshes. Unlike common approaches that segment a mesh using clustering schemes, here we introduce a method that concentrates on the contours for cutting. Our approach is based on the minima rule ... Keywords: Geometric snake, Mesh partitioning, Mesh segmentation, Part-type segmentation

Yunjin Lee; Seungyong Lee; Ariel Shamir; Daniel Cohen-Or; Hans-Peter Seidel

2005-07-01T23:59:59.000Z

147

Reformulated Gasoline Market Affected Refiners Differently, 1995  

Reports and Publications (EIA)

This article focuses on the costs of producing RFG as experienced by different types of refiners and on how these refiners fared this past summer, given the prices for RFG at the refinery gate.

John Zyren

1996-01-01T23:59:59.000Z

148

Refinement of higher-order logic programs  

Science Conference Proceedings (OSTI)

A refinement calculus provides a method for transforming specifications to executable code, maintaining the correctness of the code with respect to its specification. In this paper we extend the refinement calculus for logic programs to include higher-order ...

Robert Colvin; Ian Hayes; David Hemer; Paul Strooper

2002-09-01T23:59:59.000Z

149

Compact upwind schemes on adaptive octrees  

Science Conference Proceedings (OSTI)

Compact high-order upwind schemes using reconstruction from cell-averages are derived for application with the compressible three-dimensional Navier-Stokes equations. An adaptive-octree mesh, combined with the Adams-Bashforth-Moulton family of predictor-corrector ... Keywords: Finite-volume, High-order, Navier-Stokes, Predictor-corrector

Scott M. Murman

2010-02-01T23:59:59.000Z

150

Firing of pulverized solvent refined coal  

DOE Patents (OSTI)

An air-purged burner for the firing of pulverized solvent refined coal is constructed and operated such that the solvent refined coal can be fired without the coking thereof on the burner components. The air-purged burner is designed for the firing of pulverized solvent refined coal in a tangentially fired boiler.

Derbidge, T. Craig (Sunnyvale, CA); Mulholland, James A. (Chapel Hill, NC); Foster, Edward P. (Macungie, PA)

1986-01-01T23:59:59.000Z

151

Utah Kerosene Wholesale/Resale Volume by Refiners (Thousand ...  

U.S. Energy Information Administration (EIA)

Referring Pages: Kerosene Sales for Resale Refiner Sales Volumes; Utah Kerosene Refiner Sales Volumes; Utah Sales for Resale Refiner Sales Volumes of Aviation Fuels ...

152

Table 40. Refiners’ Operable Atmospheric Crude Oil Distillation ...  

U.S. Energy Information Administration (EIA)

Table 40. Refiners’ Operable Atmospheric Crude Oil Distillation Capacity as of January 1, 1997 Refiner Barrels per Calendar Day Refiner Barrels per

153

Zone refining of plutonium metal  

Science Conference Proceedings (OSTI)

The purpose of this study was to investigate zone refining techniques for the purification of plutonium metal. The redistribution of 10 impurity elements from zone melting was examined. Four tantalum boats were loaded with plutonium impurity alloy, placed in a vacuum furnace, heated to 700{degrees}C, and held at temperature for one hour. Ten passes were made with each boat. Metallographic and chemical analyses performed on the plutonium rods showed that, after 10 passes, moderate movement of certain elements were achieved. Molten zone speeds of 1 or 2 inches per hour had no effect on impurity element movement. Likewise, the application of constant or variable power had no effect on impurity movement. The study implies that development of a zone refining process to purify plutonium is feasible. Development of a process will be hampered by two factors: (1) the effect on impurity element redistribution of the oxide layer formed on the exposed surface of the material is not understood, and (2) the tantalum container material is not inert in the presence of plutonium. Cold boat studies are planned, with higher temperature and vacuum levels, to determine the effect on these factors. 5 refs., 1 tab., 5 figs.

NONE

1997-05-01T23:59:59.000Z

154

Anisotropic output-based adaptation with tetrahedral cut cells for compressible flows  

E-Print Network (OSTI)

Anisotropic, adaptive meshing for flows around complex, three-dimensional bodies remains a barrier to increased automation in computational fluid dynamics. Two specific advances are introduced in this thesis. First, a ...

Park, Michael Andrew

2008-01-01T23:59:59.000Z

155

Anisotropic voronoi diagrams and guaranteed-quality anisotropic mesh generation  

Science Conference Proceedings (OSTI)

We introduce anisotropic Voronoi diagrams, a generalization of multiplicatively weighted Voronoi diagrams suitable for generating guaranteed-quality meshes of domains in which long, skinny triangles are required, and where the desired anisotropy ... Keywords: anisotropic Voronoi diagram, anisotropic mesh generation

Francois Labelle; Jonathan Richard Shewchuk

2003-06-01T23:59:59.000Z

156

Experience with automatic, dynamic load balancing and adaptive finite element computation  

SciTech Connect

Distributed memory, Massively Parallel (MP), MIMD technology has enabled the development of applications requiring computational resources previously unobtainable. Structural mechanics and fluid dynamics applications, for example, are often solved by finite element methods (FEMs) requiring, millions of degrees of freedom to accurately simulate physical phenomenon. Adaptive methods, which automatically refine or coarsen meshes and vary the order of accuracy of the numerical solution, offer greater robustness and computational efficiency than traditional FEMs by reducing the amount of computation required away from physical structures such as shock waves and boundary layers. On MP computers, FEMs frequently result in distributed processor load imbalances. To overcome load imbalance, many MP FEMs use static load balancing as a preprocessor to the finite element calculation. Adaptive methods complicate the load imbalance problem since the work per element is not uniform across the solution domain and changes as the computation proceeds. Therefore, dynamic load balancing is required to maintain global load balance. We describe a dynamic, fine-grained, element-based data migration system that maintains global load balance and is effective in the presence of changing work loads. Global load balance is achieved by overlapping neighborhoods of processors, where each neighborhood performs local load balancing. The method utilizes an automatic element management system library to which a programmer integrates the application`s computational description. The library`s flexibility supports a large class of finite element and finite difference based applications.

Wheat, S.R. [Sandia National Labs., Albuquerque, NM (United States); Devine, K.D. [Rensselaer Polytechnic Inst., Troy, NY (United States). Dept. of Computer Science; Maccabe, A.B. [New Mexico Univ., Albuquerque, NM (United States). Dept. of Computer Science

1993-10-01T23:59:59.000Z

157

Carving for topology simplification of polygonal meshes  

Science Conference Proceedings (OSTI)

The topological complexity of polygonal meshes has a large impact on the performance of various geometric processing algorithms, such as rendering and collision detection algorithms. Several approaches for simplifying topology have been discussed in ... Keywords: Geometric modeling, Level-of-detail generation, Model simplification, Shape approximation, Topology simplification

Nate Hagbi; Jihad El-Sana

2010-01-01T23:59:59.000Z

158

Optimization Online - Energy Savings in Wireless Mesh Networks in ...  

E-Print Network (OSTI)

Jan 24, 2011 ... Abstract: Energy consumption of communication systems is ... Keywords: Energy savings, wireless Mesh Networks, Green networking.

159

Laboratory Evaluation of Fine-mesh Traveling Water Screens  

Science Conference Proceedings (OSTI)

This report presents final results of four years of laboratory evaluations on performance of fine-mesh traveling water screens to protect larval fish at cooling water intake structures (CWISs). Prior to this study, the biological effectiveness of fine-mesh screens was uncertain because performance data from the few existing facilities that use fine-mesh screens have been highly variable. This project is producing additional data necessary to determine biological efficacy of fine-mesh screens.

2010-12-21T23:59:59.000Z

160

Iowa Propane Wholesale/Resale Volume by Refiners (Thousand ...  

U.S. Energy Information Administration (EIA)

Referring Pages: Iowa Propane (Consumer Grade) Refiner Sales Volumes; Iowa Sales for Resale Refiner Sales Volumes of Aviation Fuels, Kerosene, ...

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


161

Alabama Propane Wholesale/Resale Volume by Refiners ...  

U.S. Energy Information Administration (EIA)

Referring Pages: Alabama Propane (Consumer Grade) Refiner Sales Volumes; Alabama Sales for Resale Refiner Sales Volumes of Aviation Fuels, Kerosene, ...

162

Table 5. Refiners' Total Operable Atmospheric Crude Oil ...  

U.S. Energy Information Administration (EIA)

CORPORATION / Refiner / Location Table 5. Refiners' Total Operable Atmospheric Crude Oil Distillation Capacity as of January 1, 2011 Calendar Day

163

Table 5. Refiners' Total Operable Atmospheric Crude Oil ...  

U.S. Energy Information Administration (EIA)

CORPORATION / Refiner / Location Table 5. Refiners' Total Operable Atmospheric Crude Oil Distillation Capacity as of January 1, 2009 Calendar Day

164

Joint watermarking and progressive geometric compression of 3D meshes  

Science Conference Proceedings (OSTI)

With the ever-increasing development of digital technologies and digital 3D models, the question of 3D mesh protection has becoming more and more important. One of the problems in digital watermarking is to decide how to embed in a 3D mesh as many bits ... Keywords: 3D compression, blind watermarking, dither modulation, semi-regular 3D meshes, wavelet transform

Ines Bouzidi; Azza Ouled Zaid; Meha Hachani; William Puech

2013-06-01T23:59:59.000Z

165

Wireless mesh network security: A traffic engineering management approach  

Science Conference Proceedings (OSTI)

The wireless mesh network (WMN) is an emerging multihop, heterogeneous, easily scalable and low cost network. The architecture of the WMN is a connectionless-oriented, mobile and dynamic traffic of routed packets. The mesh infrastructure environment ... Keywords: IPSec, MPLS, Security, Traffic engineering, VPN, Wireless mesh networks

Okechukwu E. Muogilim; Kok-Keong Loo; Richard Comley

2011-03-01T23:59:59.000Z

166

Cognitive maritime wireless mesh/ad hoc networks  

Science Conference Proceedings (OSTI)

Cognitive maritime wireless mesh/ad hoc networks are proposed in this paper, for the purpose to provide high-speed and low-cost communications for the current maritime users by incorporating the licensed but unused frequency bands opportunistically. ... Keywords: Cognitive radio networks, IEEE 802.16, Maritime communications, Maritime mesh networks, Mesh/ad hc networks, White Space

Ming-Tuo Zhou; Hiroshi Harada

2012-03-01T23:59:59.000Z

167

A CDMA/TDD approach for wireless mesh networks  

Science Conference Proceedings (OSTI)

Wide band mesh or star oriented networks have recently become a subject of greater interest. Providing wideband multimedia access for a variety of applications has led to the inception of mesh networks. Classic access techniques such as FDMA and TDMA ... Keywords: Mesh networks, TDD, TDMA, WCDMA

Imam Al-wazedi; Ahmed K. Elhakeem

2010-09-01T23:59:59.000Z

168

MAC protocols over wireless mesh networks: problems and perspective  

Science Conference Proceedings (OSTI)

The wireless mesh network (WMN) has been an emerging technology in recent years. Because the transmission medium used in networking backhaul access points (APs) is radio, the wireless mesh network is not only easy and cost effective in deployment, but ... Keywords: Coordinated distributed scheduling, IEEE 802.11, IEEE 802.16, MAC, TDMA, Wireless mesh networks (WMNs)

V. Loscr?

2008-03-01T23:59:59.000Z

169

Metallurgical Silicon Refining by Transient Directional Solidification  

Science Conference Proceedings (OSTI)

Abstract Scope, Directional solidification is an essential refining step to obtain solar ... The chemical analyses of the ingots show macrosegregation of several ...

170

Vacuum Distillation Refining of Crude Tin - Thermodynamics ...  

Science Conference Proceedings (OSTI)

Presentation Title, Vacuum Distillation Refining of Crude Tin - Thermodynamics Analysis and Experiments on the Removal of Arsenic from the Crude Tin.

171

U. S. refiners move into another challenging technical era  

Science Conference Proceedings (OSTI)

With the transition to unleaded gasoline scarcely behind us, another new era is dawning for the U.S. refiner. No one yet knows the exact configuration of the refinery of the future and no two refineries are likely to adapt in exactly the same way. What is certain, however, is that by the year 2000, refineries will be more technologically advanced, their products will be more environmentally acceptable, and their operators will be more highly trained. The typical U.S. refinery in the year 2000 will be located at an existing refinery site because economic and environmental considerations will make it impossible to build new grassroots capacity. As a result of the Clean Air act, the refinery of tomorrow will produce cleaner fuels The entire U.S. gasoline pool will likely be reformulated. Most of the diesel fuel pool will consist of ultralow-sulfur product. And jet fuel-which is experiencing rapid demand growth-will be an increasingly important product. Many existing refining process will remain in use, but they will be more efficient and more technologically advanced. Energy efficiency will be a primary concern, as refiners seek to combat ever-increasing crude oil costs and refinery operating expenses. The refinery of the future also will be much more environmentally acceptable. The article is a closer look at the refinery of the future.

Hall, J.R. (Ashland Oil Inc., Ashland, KY (US))

1991-10-21T23:59:59.000Z

172

Mesh Generation for SHARP: Unprecedented Complexity | Department of Energy  

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

Mesh Generation for SHARP: Unprecedented Complexity Mesh Generation for SHARP: Unprecedented Complexity Mesh Generation for SHARP: Unprecedented Complexity January 29, 2013 - 1:36pm Addthis SHARP Supporting Elements During this quarter, the framework team was involved in two primary efforts, mesh generation and implementation of a MOAB-based coupled multi-physics simulation. For mesh generation, finishing touches were put on three major, high-complexity hexahedral meshes, and support was provided for their use in various simulations: MATiS-H, an OECD-NEA experiment for single-phase flow over a rod bundle and grid. [ANL] Nuscale, a hexahedral mesh of the core internals of the Multi-Application Small Light Water Reactor, a 1/3-scale mockup of the Nuscale reactor. [ANL] XX09, a high-fidelity model of the XX09 test fuel assembly used in

173

Data-Parallel Mesh Connected Components Labeling and Analysis  

SciTech Connect

We present a data-parallel algorithm for identifying and labeling the connected sub-meshes within a domain-decomposed 3D mesh. The identification task is challenging in a distributed-memory parallel setting because connectivity is transitive and the cells composing each sub-mesh may span many or all processors. Our algorithm employs a multi-stage application of the Union-find algorithm and a spatial partitioning scheme to efficiently merge information across processors and produce a global labeling of connected sub-meshes. Marking each vertex with its corresponding sub-mesh label allows us to isolate mesh features based on topology, enabling new analysis capabilities. We briefly discuss two specific applications of the algorithm and present results from a weak scaling study. We demonstrate the algorithm at concurrency levels up to 2197 cores and analyze meshes containing up to 68 billion cells.

Harrison, Cyrus; Childs, Hank; Gaither, Kelly

2011-04-10T23:59:59.000Z

174

Pneumatic conveying of pulverized solvent refined coal  

DOE Patents (OSTI)

A method for pneumatically conveying solvent refined coal to a burner under conditions of dilute phase pneumatic flow so as to prevent saltation of the solvent refined coal in the transport line by maintaining the transport fluid velocity above approximately 95 ft/sec.

Lennon, Dennis R. (Allentown, PA)

1984-11-06T23:59:59.000Z

175

Refined computational models for laminated shells  

Science Conference Proceedings (OSTI)

This paper presents refined computational models for non homogeneous, deep, doubly curved shells. The theory is based on a kinematical approach in which the continuity conditions for displacements and shear stresses at layer interfaces and on the bounding ... Keywords: bending-torsion warping coupling, multilayered shells, piezoelectric laminates, shear-membrane refinements, stress computations, triangular C1-C1/2 finite element

M. Touratier

2002-01-01T23:59:59.000Z

176

North Dakota Refining Capacity Study  

Science Conference Proceedings (OSTI)

According to a 2008 report issued by the United States Geological Survey, North Dakota and Montana have an estimated 3.0 to 4.3 billion barrels of undiscovered, technically recoverable oil in an area known as the Bakken Formation. With the size and remoteness of the discovery, the question became 'can a business case be made for increasing refining capacity in North Dakota?' And, if so what is the impact to existing players in the region. To answer the question, a study committee comprised of leaders in the region's petroleum industry were brought together to define the scope of the study, hire a consulting firm and oversee the study. The study committee met frequently to provide input on the findings and modify the course of the study, as needed. The study concluded that the Petroleum Area Defense District II (PADD II) has an oversupply of gasoline. With that in mind, a niche market, naphtha, was identified. Naphtha is used as a diluent used for pipelining the bitumen (heavy crude) from Canada to crude markets. The study predicted there will continue to be an increase in the demand for naphtha through 2030. The study estimated the optimal configuration for the refinery at 34,000 barrels per day (BPD) producing 15,000 BPD of naphtha and a 52 percent refinery charge for jet and diesel yield. The financial modeling assumed the sponsor of a refinery would invest its own capital to pay for construction costs. With this assumption, the internal rate of return is 9.2 percent which is not sufficient to attract traditional investment given the risk factor of the project. With that in mind, those interested in pursuing this niche market will need to identify incentives to improve the rate of return.

Dennis Hill; Kurt Swenson; Carl Tuura; Jim Simon; Robert Vermette; Gilberto Marcha; Steve Kelly; David Wells; Ed Palmer; Kuo Yu; Tram Nguyen; Juliam Migliavacca

2011-01-05T23:59:59.000Z

177

On the Construction of WiMax Mesh Tree  

E-Print Network (OSTI)

Abstract — The IEEE 802.16 protocol, also known as WiMAX, has been designed to support long-range communications with high bitrates, using two operation modes: Point-to-Multi-Point (PMP) and Mesh. In the mesh mode, Subscriber Stations (SSs) can directly communicate with each other, thus forming a tree, and can be used to forward other’s data packets in a multihop fashion. On the contrary, in the PMP mode only one hop communication toward the Base Station (BS) is allowed. In this paper, we investigate the performance of the mesh mode by proposing an algorithm for constructing the WiMAX mesh tree. Our algorithm increases routes ’ effective throughput by splitting long links into multiple shorter ones. We show through simulations that this approach leads to improving the throughput capacity of WiMAX-based wireless mesh networks. Index Terms — WiMAX, wireless mesh networks. I.

Salim Nahle; Luigi Iannone; Benoit Donnet; Naceur Malouch

2007-01-01T23:59:59.000Z

178

Firing of pulverized solvent refined coal  

SciTech Connect

A burner for the firing of pulverized solvent refined coal is constructed and operated such that the solvent refined coal can be fired successfully without any performance limitations and without the coking of the solvent refined coal on the burner components. The burner is provided with a tangential inlet of primary air and pulverized fuel, a vaned diffusion swirler for the mixture of primary air and fuel, a center water-cooled conical diffuser shielding the incoming fuel from the heat radiation from the flame and deflecting the primary air and fuel steam into the secondary air, and a watercooled annulus located between the primary air and secondary air flows.

Lennon, Dennis R. (Allentown, PA); Snedden, Richard B. (McKeesport, PA); Foster, Edward P. (Macungie, PA); Bellas, George T. (Library, PA)

1990-05-15T23:59:59.000Z

179

Hierarchy-Direction Selective Approach for Locally Adaptive Sparse Grids  

SciTech Connect

We consider the problem of multidimensional adaptive hierarchical interpolation. We use sparse grids points and functions that are induced from a one dimensional hierarchical rule via tensor products. The classical locally adaptive sparse grid algorithm uses an isotropic refinement from the coarser to the denser levels of the hierarchy. However, the multidimensional hierarchy provides a more complex structure that allows for various anisotropic and hierarchy selective refinement techniques. We consider the more advanced refinement techniques and apply them to a number of simple test functions chosen to demonstrate the various advantages and disadvantages of each method. While there is no refinement scheme that is optimal for all functions, the fully adaptive family-direction-selective technique is usually more stable and requires fewer samples.

Stoyanov, Miroslav K [ORNL] [ORNL

2013-09-01T23:59:59.000Z

180

2011 Short Course Basics of Edible Oil Processing and Refining  

Science Conference Proceedings (OSTI)

Basics of Edible Oil Processing and Refining held at the 102nd AOCS Annual Meeting and Expo. 2011 Short Course Basics of Edible Oil Processing and Refining Basics of Edible Oil Processing and Refining Short Course Saturday April 30,

Note: This page contains sample records for the topic "adaptive mesh refinement" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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181

2013 Short Course Fundamentals of Edible Oil Processing and Refining  

Science Conference Proceedings (OSTI)

Fundamentals of Edible Oil Processing and Refining Short Course held at the 104th AOCS Annual Meeting and Expo. 2013 Short Course Fundamentals of Edible Oil Processing and Refining Fundamentals of Edible Oil Processing and Refining S

182

2010 Short Course Basics of Edible Oil Processing and Refining  

Science Conference Proceedings (OSTI)

Basics of Edible Oil Processing and Refining Short Course held at the 101st AOCS Annual Meeting and Expo. 2010 Short Course Basics of Edible Oil Processing and Refining Basics of Edible Oil Processing and Refining Short Course Saturday, M

183

New MOAB mesh software version released | Argonne National Laboratory  

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

can represent most mesh types used in PDE-solving applications, such as fluid dynamics, fusion modeling, and multiphysics reactor simulation." MOAB provides efficient storage of...

184

Hexahedral finite element mesh coarsening using pillowing technique  

SciTech Connect

A techniques for coarsening a hexahedral mesh is described. The technique includes identifying a coarsening region within a hexahedral mesh to be coarsened. A boundary sheet of hexahedral elements is inserted into the hexahedral mesh around the coarsening region. A column of hexahedral elements is identified within the boundary sheet. The column of hexahedral elements is collapsed to create an extraction sheet of hexahedral elements contained within the coarsening region. Then, the extraction sheet of hexahedral elements is extracted to coarsen the hexahedral mesh.

Staten, Matthew L. (Pittsburgh, PA); Woodbury, Adam C. (Provo, UT); Benzley, Steven E. (Provo, UT); Shepherd, Jason F. (Edgewood, NM)

2012-06-05T23:59:59.000Z

185

Valero Refining Company - NJ | Open Energy Information  

Open Energy Info (EERE)

Valero Refining Company - NJ Valero Refining Company - NJ Jump to: navigation, search Name Valero Refining Company - NJ Place New Jersey Utility Id 56325 Utility Location Yes Ownership R Operates Generating Plant Yes Activity Retail Marketing Yes References EIA Form EIA-861 Final Data File for 2010 - File1_a[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Utility Rate Schedules Grid-background.png No rate schedules available. Average Rates Industrial: $0.0652/kWh References ↑ "EIA Form EIA-861 Final Data File for 2010 - File1_a" Retrieved from "http://en.openei.org/w/index.php?title=Valero_Refining_Company_-_NJ&oldid=411921" Categories: EIA Utility Companies and Aliases

186

U.S. Refining Capacity Utilization  

Reports and Publications (EIA)

This article briefly reviews recent trends in domestic refining capacity utilization and examines in detail the differences in reported crude oil distillation capacities and utilization rates among different classes of refineries.

Tancred Lidderdale

1995-10-01T23:59:59.000Z

187

2004: Sign of the Future for Refiners?  

Reports and Publications (EIA)

A presentation to the NPRA Annual Meeting discussing the major factors that drove petroleum prices, price differentials, and margins in 2004, and what this might mean for refiners as we look towards the future.

Information Center

2005-03-14T23:59:59.000Z

188

Genealogy Of Major U.S. Refiners  

Reports and Publications (EIA)

A summary presentation iof mergers and acquisitions by U.S. major oil companies (including the U.S. affiliates of foreign major oil companies). The presentation focuses on petroleum refining over the last several years through late 2009.

Neal Davis

2009-12-02T23:59:59.000Z

189

MOCUM: A two-dimensional method of characteristics code based on unstructured meshing for general geometries  

Science Conference Proceedings (OSTI)

A transport theory code MOCUM based on the Method of Characteristics (MOC) as the flux solver with an advanced general geometry processor is developed for two-dimensional lattice and full core neutronics modeling. The core structure is represented by Constructive Solid Geometry (CSG) that uses Boolean operations to build complex geometries from simple polygons. Arbitrary-precision arithmetic is also used in the process of building CSG objects to eliminate the round-off error from the commonly used double precision numbers. Then, the constructed core frame will be decomposed and refined into a conforming Delaunay triangulation to ensure the quality of the meshes. The MOC solver kernel is fully paralleled using OpenMP and the developed numerical code is validated by several benchmarks representing various core geometries. For the cases modeled, the maximum percentage error for multiplication factor and the pin power compared to reference values are 0.1% and 0.7% respectively. (authors)

Yang, X.; Satvat, N. [School of Nuclear Engineering, Purdue Univ., 400 Central Dr, West Lafayette, IN 47907 (United States)

2012-07-01T23:59:59.000Z

190

Genealogy of major U.S. refiners  

U.S. Energy Information Administration (EIA) Indexed Site

of major U.S. refiners of major U.S. refiners 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 Amoco SOHIO BP ARCO Mapco Williams Clark Refining 1/89 12/98 4/00 3/98 Orion Diamond Shamrock Ultramar k 12/96 7/03 Ultramar Diamond Shamrock (UDS) Total North America UDS 9/97 Valero Salomon (Basis) Valero Williams BP BP b BP-Husky Refining LLC (jv) Husky Huntway 5/97 6/01 9/05 Valero Premcor g Valero Valero Valero 12/01 7/94 e 12/98 f Carlyle Group y Coastal 3/03 d 12/88 a 6/01 o Sun Company Sunoco v 7/07 i 4/08 c 5/04 h Pacific Refining (jv) 12/88 r El Paso 1/04 w 10/98 m 6/00 n 9/89 t 8/94 u See notes, footnotes, and source notes below. PBF Energy 6/10 p 12/10 q 3/11 x 10/11 j 9/00 l 1/01 s Genealogy of major U.S. refiners (continued) 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013

191

Finding Regions of Interest on Toroidal Meshes  

SciTech Connect

Fusion promises to provide clean and safe energy, and a considerable amount of research effort is underway to turn this aspiration intoreality. This work focuses on a building block for analyzing data produced from the simulation of microturbulence in magnetic confinementfusion devices: the task of efficiently extracting regions of interest. Like many other simulations where a large amount of data are produced,the careful study of ``interesting'' parts of the data is critical to gain understanding. In this paper, we present an efficient approach forfinding these regions of interest. Our approach takes full advantage of the underlying mesh structure in magnetic coordinates to produce acompact representation of the mesh points inside the regions and an efficient connected component labeling algorithm for constructingregions from points. This approach scales linearly with the surface area of the regions of interest instead of the volume as shown with bothcomputational complexity analysis and experimental measurements. Furthermore, this new approach is 100s of times faster than a recentlypublished method based on Cartesian coordinates.

Wu, Kesheng; Sinha, Rishi R; Jones, Chad; Ethier, Stephane; Klasky, Scott; Ma, Kwan-Liu; Shoshani, Arie; Winslett, Marianne

2011-02-09T23:59:59.000Z

192

U.S. Crude Oil Imported Acquisition Cost by Refiners ...  

U.S. Energy Information Administration (EIA)

Release Date: 1/2/2014: Next Release Date: 2/3/2014: Referring Pages: Refiner Acquisition Cost of Imported Crude Oil ; U.S. Refiner Acquisition Cost ...

193

Idaho Kerosene-Type Jet Fuel Retail Sales by Refiners ...  

U.S. Energy Information Administration (EIA)

Referring Pages: Idaho Kerosene-Type Jet Fuel Refiner Sales Volumes; Idaho Sales to End Users Refiner Sales Volumes of Aviation Fuels, Kerosene, ...

194

Idaho Kerosene Wholesale/Resale Volume by Refiners (Thousand ...  

U.S. Energy Information Administration (EIA)

Referring Pages: Idaho Kerosene Refiner Sales Volumes; Idaho Sales for Resale Refiner Sales Volumes of Aviation Fuels, Kerosene, Propane, No.1 and No. ...

195

Vermont Propane Retail Sales by Refiners (Thousand Gallons per Day)  

U.S. Energy Information Administration (EIA)

Referring Pages: Propane (Consumer Grade) Sales to End Users Refiner Sales Volumes; Vermont Propane (Consumer Grade) Refiner Sales Volumes; Vermont Sales to End Users ...

196

Practical Guide to Vegetable Oil ProcessingChapter 4 Refining  

Science Conference Proceedings (OSTI)

Practical Guide to Vegetable Oil Processing Chapter 4 Refining Processing eChapters Processing Press Downloadable pdf of Chapter 4 Refining from the book ...

197

Numerical simulation of four-field extended magnetohydrodynamics in dynamically adaptive curvilinear coordinates via Newton-Krylov-Schwarz  

Science Conference Proceedings (OSTI)

Numerical simulations of the four-field extended magnetohydrodynamics (MHD) equations with hyper-resistivity terms present a difficult challenge because of demanding spatial resolution requirements. A time-dependent sequence of r-refinement adaptive ... Keywords: Dynamically adaptive grid, Equidistribution principle, MHD, Magnetic reconnection, Monge-Ampère equation, Monge-Kantorovich optimization, NKS, Structured grid, r-Refinement

Xuefei Yuan; Stephen C. Jardin; David E. Keyes

2012-07-01T23:59:59.000Z

198

Topology-adaptive interface tracking using the deformable simplicial complex  

Science Conference Proceedings (OSTI)

We present a novel, topology-adaptive method for deformable interface tracking, called the Deformable Simplicial Complex (DSC). In the DSC method, the interface is represented explicitly as a piecewise linear curve (in 2D) or surface (in 3D) which ... Keywords: Deformable models, surface tracking, tetrahedral meshes

Marek Krzysztof Misztal; Jakob Andreas Bærentzen

2012-05-01T23:59:59.000Z

199

Table 5.22 Refiner Sales Prices and Refiner Margins for ...  

U.S. Energy Information Administration (EIA)

1 Prices are not adjusted for inflation. See "Nominal Dollars" in Glossary. 6 A volume weighted average of the refiner prices to resellers for ...

200

Metal decontamination for waste minimization using liquid metal refining technology  

Science Conference Proceedings (OSTI)

The current Department of Energy Mixed Waste Treatment Project flowsheet indicates that no conventional technology, other than surface decontamination, exists for metal processing. Current Department of Energy guidelines require retrievable storage of all metallic wastes containing transuranic elements above a certain concentration. This project is in support of the National Mixed Low Level Waste Treatment Program. Because of the high cost of disposal, it is important to develop an effective decontamination and volume reduction method for low-level contaminated metals. It is important to be able to decontaminate complex shapes where surfaces are hidden or inaccessible to surface decontamination processes and destruction of organic contamination. These goals can be achieved by adapting commercial metal refining processes to handle radioactive and organic contaminated metal. The radioactive components are concentrated in the slag, which is subsequently vitrified; hazardous organics are destroyed by the intense heat of the bath. The metal, after having been melted and purified, could be recycled for use within the DOE complex. In this project, we evaluated current state-of-the-art technologies for metal refining, with special reference to the removal of radioactive contaminants and the destruction of hazardous organics. This evaluation was based on literature reports, industrial experience, plant visits, thermodynamic calculations, and engineering aspects of the various processes. The key issues addressed included radioactive partitioning between the metal and slag phases, minimization of secondary wastes, operability of the process subject to widely varying feed chemistry, and the ability to seal the candidate process to prevent the release of hazardous species.

Joyce, E.L. Jr.; Lally, B. [Los Alamos National Lab., NM (United States); Ozturk, B.; Fruehan, R.J. [Carnegie-Mellon Univ., Pittsburgh, PA (United States). Dept. of Materials Science and Engineering

1993-09-01T23:59:59.000Z

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


201

Modeling dynamic developable meshes by the Hamilton principle  

Science Conference Proceedings (OSTI)

In this paper, a new dynamic developable surface model is proposed. The proposed model represents developable surfaces using triangle meshes. A novel algorithm is proposed to introduce the Hamilton principle into these meshes such that the resulting ... Keywords: Developable surface, Hamilton principle, Physical-based simulation

Yong-Jin Liu; Kai Tang; Ajay Joneja

2007-09-01T23:59:59.000Z

202

One-to-many: example-based mesh animation synthesis  

Science Conference Proceedings (OSTI)

We propose an example-based approach for synthesizing diverse mesh animations. Provided a short clip of deformable mesh animation, our method synthesizes a large number of different animations of arbitrary length. Combining an automatically inferred ... Keywords: animation, bone graph, cut node, synthesis, transition

Changxi Zheng

2013-07-01T23:59:59.000Z

203

Metallic Mesh Filter Used for Electromagnetic Shielding of Infrared Window  

Science Conference Proceedings (OSTI)

In order to meet anti-electromagnetism interference performance requirements of infrared window, a metallic mesh coating must be used on the infrared window. From the diffraction theory of grating and the equivalent circuit method, simplified expressions ... Keywords: stealth technology, electro-optical countermeasure, transparent conductive coating, metallic mesh filter, infrared window

Jia-Li Song, Xiao-Guo Feng

2012-07-01T23:59:59.000Z

204

Mitigating multi-path fading in a mobile mesh network  

Science Conference Proceedings (OSTI)

By using robots as routers, a team of networked robots can provide a communication substrate to establish a wireless mesh network. The mobile mesh network can autonomously optimize its configuration, increasing performance. One of the main sources of ... Keywords: Complex environments, Distributed optimization, Experimental and prototype results, Mobile and wireless ad-hoc networks, Multi-path fading

Marcos A. M. Vieira, Matthew E. Taylor, Prateek Tandon, Manish Jain, Ramesh Govindan, Gaurav S. Sukhatme, Milind Tambe

2013-06-01T23:59:59.000Z

205

Realizing and benchmarking broadcast algorithms in wireless mesh networks  

Science Conference Proceedings (OSTI)

Broadcasting by flooding causes the broadcast storm problem in multi-hop wireless networks. This problem becomes more likely in a wireless mesh network (WMN) because WMNs can bridge wired LANs, increasing broadcast traffic and collision probability. ... Keywords: 802.11s, Broadcast algorithm, Mesh networks, Multi-hop wireless networks, WMN

Ying-Dar Lin; Shun-Lee Chang; Shi-Hung Tao; Jui-Hung Yeh

2011-07-01T23:59:59.000Z

206

A topology-independent scheduling scheme for wireless mesh networks  

Science Conference Proceedings (OSTI)

To meet the needs of wireless broadband access, the IEEE 802.16 protocol for wireless metropolitan networks had been recently standardized. The medium access control (MAC) layer of the IEEE 802.16 has point-to-multipoint (PMP) mode and mesh mode. Previous ... Keywords: 802.16, MAC, TDMA, mesh networks, scheduling sheme, wireless

V. Loscri

2007-10-01T23:59:59.000Z

207

Distributed scheduling schemes for wireless mesh networks: A survey  

Science Conference Proceedings (OSTI)

An efficient scheduling scheme is a crucial part of Wireless Mesh Networks (WMNs)—an emerging communication infrastructure solution for autonomy, scalability, higher throughput, lower delay metrics, energy efficiency, and other service-level guarantees. ... Keywords: Wireless mesh networks, ad hoc networks, cyclic access, distributed scheduling schemes, pseudo-random access, random access

Kanthaiah Sivapragasam Vijayalayan, Aaron Harwood, Shanika Karunasekera

2013-10-01T23:59:59.000Z

208

The Uranium Processing Facility Finite Element Meshing Discussion  

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

Uranium Processing Facility (UPF) Uranium Processing Facility (UPF) Finite Element Meshing Discussion ...Need picture of Building... October 25, 2011 Department of Energy - Natural Phenomenon Hazard Workshop 1 Loring Wyllie Arne Halterman Degenkolb Engineers, San Francisco Purpose of Presentation * Design vs. Analysis * Discuss the mesh criteria * Discuss the evolution of the mesh of the UPF main building model * Discuss how the mesh affects the analysis process October 25, 2011 2 Department of Energy - Natural Phenomenon Hazard Workshop FEM Modeling * GTStrudl typically used for DOE projects. * Mesh size is important * What is to be captured? * How complex is the system? * Current criteria set to capture in-plane and out-of-plane response. October 25, 2011 3

209

Moving mesh cosmology: tracing cosmological gas accretion  

E-Print Network (OSTI)

We investigate the nature of gas accretion onto haloes and galaxies at z=2 using cosmological hydrodynamic simulations run with the moving mesh code AREPO. Implementing a Monte Carlo tracer particle scheme to determine the origin and thermodynamic history of accreting gas, we make quantitative comparisons to an otherwise identical simulation run with the smoothed particle hydrodynamics (SPH) code GADGET-3. Contrasting these two numerical approaches, we find significant physical differences in the thermodynamic history of accreted gas in haloes above 10^10.5 solar masses. In agreement with previous work, GADGET simulations show a cold fraction near unity for galaxies forming in massive haloes, implying that only a small percentage of accreted gas heats to an appreciable fraction of the virial temperature during accretion. The same galaxies in AREPO show a much lower cold fraction, gas accretion rate which, at this same halo mass, is an order o...

Nelson, Dylan; Genel, Shy; Sijacki, Debora; Keres, Dusan; Springel, Volker; Hernquist, Lars

2013-01-01T23:59:59.000Z

210

Changing World Product Markets and Potential Refining Capacity ...  

U.S. Energy Information Administration (EIA)

Changing World Product Markets and Potential Refining Capacity Increases. NPRA Annual Meeting March 2006

211

Minnesota, Wisconsin, North and South Dakota Refining District ...  

U.S. Energy Information Administration (EIA)

Minnesota, Wisconsin, North and South Dakota Refining District Percent Utilization of Refinery Operable Capacity (Percent)

212

Refining District New Mexico Gross Inputs to Atmospheric Crude Oil ...  

U.S. Energy Information Administration (EIA)

Refining District New Mexico Gross Inputs to Atmospheric Crude Oil Distillation Units (Thousand Barrels per Day)

213

Texas Inland Refining District Operable Crude Oil Distillation ...  

U.S. Energy Information Administration (EIA)

Texas Inland Refining District Operable Crude Oil Distillation Capacity (Thousand Barrels per Calendar Day)

214

East Coast Refining District Operable Crude Oil Distillation ...  

U.S. Energy Information Administration (EIA)

East Coast Refining District Operable Crude Oil Distillation Capacity (Thousand Barrels per Calendar Day)

215

Refining District Minnesota-Wisconsin-North Dakota-South ...  

U.S. Energy Information Administration (EIA)

Refining District Minnesota-Wisconsin-North Dakota-South Dakota Refinery Yield of Petroleum Coke (Percent)

216

Hydrogen Piping Experience in Chevron Refining  

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

Piping Piping Experience in Chevron Refining Ned Niccolls Materials Engineer Chevron Energy Technology Company Hydrogen Pipeline Working Group Workshop August 30-31, 2005 Outline 2 Overall perspectives from long term use of hydrogen piping in refining. Piping specifications and practices. The (few) problem areas. Related industry work: American Petroleum Institute corrosion and materials work on high temperature hydrogen attack. Overall Perspectives 3 Few problems with hydrogen piping operating at ambient to at least 800F and pressures up to at least 3000psia as long as we stay within well- defined limits H2S contamination presents many more problems, beyond the scope of this talk We will note a couple of specific vulnerabilities Refining tracks materials performance in

217

Minimally refined biomass fuels: an economic shortcut  

DOE Green Energy (OSTI)

An economic shortcut can be realized if the sugars from which ethanol is made are utilized directly as concentrated aqueous solutions for fuels rather than by further refining them through fermentation and distillation steps. Simple evaporation of carbohydrate solutions from sugar cane or sweet sorghum, or from hydrolysis of starch or cellulose content of many plants yield potential liquid fuels of energy contents (on a volume basis) comparable to highly refined liquid fuels like methanol and ethanol. The potential utilization of such minimally refined biomass derived fuels is discussed and the burning of sucrose-ethanol-water solutions in a small modified domestic burner is demonstrated. Other potential uses of sugar solutions or emulsion and microemulsions in fuel oils for use in diesel or turbine engines are proposed and discussed.

Pearson, R.K.; Hirschfeld, T.B.

1980-07-01T23:59:59.000Z

218

Norwegian Silicon Refining AS | Open Energy Information  

Open Energy Info (EERE)

Refining AS Refining AS Jump to: navigation, search Name Norwegian Silicon Refining AS Place Oslo, Norway Zip 214 Product Oslo-based company with an upgraded metallurgical silicon (UMG) production process called the Stubergh method. Coordinates 59.91228°, 10.74998° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":59.91228,"lon":10.74998,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

219

1995 Reformulated Gasoline Market Affected Refiners Differently  

Gasoline and Diesel Fuel Update (EIA)

5 Reformulated Gasoline Market Affected 5 Reformulated Gasoline Market Affected Refiners Differently by John Zyren, Charles Dale and Charles Riner Introduction The United States has completed its first summer driving season using reformulated gasoline (RFG). Motorists noticed price increases at the retail level, resulting from the increased cost to produce and deliver the product, as well as from the tight sup- ply/demand balance during the summer. This arti- cle focuses on the costs of producing RFG as experienced by different types of refiners and on how these refiners fared this past summer, given the prices for RFG at the refinery gate. RFG Regulatory Requirements The use of RFG is a result of the Clean Air Act Amendments of 1990 (CAAA). The CAAA cover a wide range of programs aimed at improving air qual-

220

An Application-Centric Characterization of Domain-Based SFC Partitioners for Parallel SAMR  

Science Conference Proceedings (OSTI)

Abstract¿Structured adaptive mesh refinement (SAMR) methods for the numerical solution of partial differential equations yield highly advantageous ratios for cost/accuracy as compared to methods based on static uniform approximations. These techniques ... Keywords: Dynamic domain-based partitioning and load-balancing, inverse space-filling curve partitioning, performance characterization, structured adaptive mesh refinement, adaptive metapartitioner.

Johan Steensland; Sumir Chandra; Manish Parashar

2002-12-01T23:59:59.000Z

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


221

SEARCH NAVIGATE REFINE PERSONALIZE SAVE SEARCH OPERATORS  

E-Print Network (OSTI)

SEARCH NAVIGATE REFINE PERSONALIZE SAVE SEARCH OPERATORS Search using AND, OR, NOT, and SAME (same sentence) to create logical search state- ments. Nest search operators inside parentheses. Search exact Web of Science® Quick Reference Card Search over 9,200 journals from over 45 different languages

Russell, Lynn

222

A Cluster Refinement Algorithm for Motif Discovery  

Science Conference Proceedings (OSTI)

Finding Transcription Factor Binding Sites, i.e., motif discovery, is crucial for understanding the gene regulatory relationship. Motifs are weakly conserved and motif discovery is an NP-hard problem. We propose a new approach called Cluster Refinement ... Keywords: Transcription factor binding site, motif discovery.

Gang Li; Tak-Ming Chan; Kwong-Sak Leung; Kin-Hong Lee

2010-10-01T23:59:59.000Z

223

Arnold Schwarzenegger REFINING ESTIMATES OF WATER-  

E-Print Network (OSTI)

of magnitude of waterrelated energy use do not consider energy that is produced as a byproduct of water supply decrease in a dry year. The amount of water delivered or hydropower produced depends on a number Arnold Schwarzenegger Governor REFINING ESTIMATES OF WATER- RELATED ENERGY USE IN CALIFORNIA

224

Deriving Efficient Cache Coherence Protocols Through Refinement  

Science Conference Proceedings (OSTI)

We address the problem of developing efficient cache coherence protocols for use in distributed systems implementing distributed shared memory (DSM) using message passing. A serious drawback of traditional approaches to this problem is that the users ... Keywords: DSM protocols, communication protocols, refinement

Ratan Nalumasu; Ganesh Gopalakrishnan

2002-01-01T23:59:59.000Z

225

Ontology-based automatic query refinement  

Science Conference Proceedings (OSTI)

The effectiveness of user query plays a vital role in retrieving highly relevant documents in keyword-based search engine. Because of the lack of domain knowledge, users tend to post very short queries, which do not express their information need ... Keywords: automatic query refinement, document retrieval, information retrieval, keywords, ontology, query expansion, retrieval relevancy, search engines, semantic search, user queries

S. Sendhilkumar; G. S. Mahalakshmi; S. N. Rajasekar

2009-07-01T23:59:59.000Z

226

Hydrocarbon Processing`s refining processes `96  

Science Conference Proceedings (OSTI)

The paper compiles information on the following refining processes: alkylation, benzene reduction, benzene saturation, catalytic cracking, catalytic reforming, coking, crude distillation, deasphalting, deep catalytic cracking, electrical desalting, ethers, fluid catalytic cracking, hydrocracking, hydrogenation, hydrotreating, isomerization, resid catalytic cracking, treating, and visbreaking. The application, products, a description of the process, yield, economics, installation, and licensor are given for each entry.

NONE

1996-11-01T23:59:59.000Z

227

From Mesh Generation to Scientific Visualization:  

E-Print Network (OSTI)

Parallel supercomputing has typically focused on the inner kernel of scientific simulations: the solver. The front and back ends of the simulation pipeline---problem description and interpretation of the output---have taken a back seat to the solver when it comes to attention paid to scalability and performance, and are often relegated to offline, sequential computation. As the largest simulations move beyond the realm of the terascale and into the petascale, this decomposition in tasks and platforms becomes increasingly untenable. We propose an end-to-end approach in which all simulation components---meshing, partitioning, solver, and visualization---are tightly coupled and execute in parallel with shared data structures and no intermediate I/O. We present our implementation of this new approach in the context of octree-based finite element simulation of earthquake ground motion. Performance evaluation on up to 2048 processors demonstrates the ability of the end-toend approach to overcome the scalability bottlenecks of the traditional approach.

An End-To-End Approach; Tiankai Tu; Hongfeng Yu; Leonardo Ramirez-guzman; Jacobo Bielak; Omar Ghattas; Kwan-liu Ma; David R. O’hallaron

2006-01-01T23:59:59.000Z

228

LOCATE intelligent systems demonstration: adapting help to the cognitive styles of users  

Science Conference Proceedings (OSTI)

LOCATE is workspace layout design software that also serves as a testbed for developing and refining principles of adaptive aiding. This demonstration illustrates LOCATE's ability to determine user cognitive styles and provide help matched to those styles. ...

Jack L. Edwards; Greg Scott

2006-07-01T23:59:59.000Z

229

Municipal wireless mesh networks as a competitive broadband delivery platform  

E-Print Network (OSTI)

Recently there has been a growing interest in deploying Wireless Mesh Networks by municipalities. This interest stems from the desire to provide broadband connectivity to users lacking access to broadband alternatives. The ...

Hassan-Ali, Mudhafar

2007-01-01T23:59:59.000Z

230

TDM MAC protocol design and implementation for wireless mesh networks  

Science Conference Proceedings (OSTI)

We present the design, implementation, and evaluation of a Time Division Multiplex (TDM) MAC protocol for multi-hop wireless mesh networks using a programmable wireless platform. Extensive research has been devoted to optimal scheduling algorithms for ...

Dimitrios Koutsonikolas; Theodoros Salonidis; Henrik Lundgren; Pascal LeGuyadec; Y. Charlie Hu; Irfan Sheriff

2008-12-01T23:59:59.000Z

231

Analyte separation utilizing temperature programmed desorption of a preconcentrator mesh  

DOE Patents (OSTI)

A method and system for controllably releasing contaminants from a contaminated porous metallic mesh by thermally desorbing and releasing a selected subset of contaminants from a contaminated mesh by rapidly raising the mesh to a pre-determined temperature step or plateau that has been chosen beforehand to preferentially desorb a particular chemical specie of interest, but not others. By providing a sufficiently long delay or dwell period in-between heating pulses, and by selecting the optimum plateau temperatures, then different contaminant species can be controllably released in well-defined batches at different times to a chemical detector in gaseous communication with the mesh. For some detectors, such as an Ion Mobility Spectrometer (IMS), separating different species in time before they enter the IMS allows the detector to have an enhanced selectivity.

Linker, Kevin L. (Albuquerque, NM); Bouchier, Frank A. (Albuquerque, NM); Theisen, Lisa (Albuquerque, NM); Arakaki, Lester H. (Edgewood, NM)

2007-11-27T23:59:59.000Z

232

Steel Mesh Coated with Carbon Nanotubes: Its Superhydrophobicity ...  

Science Conference Proceedings (OSTI)

Oil, on the other hand, completely wet the SS-CNTs mesh. Simple ... Application of Biomass Waste Materials in the Nano Mineral Synthesis .... of Iron-Carbon Nanocomposites by Laser Power Variation Throughout the Laser Pyrolysis Process.

233

SMI 2011: Full Paper: Parallel computation of spherical parameterizations for mesh analysis  

Science Conference Proceedings (OSTI)

Mesh parameterization is central to a broad spectrum of applications. In this paper, we present a novel approach to spherical mesh parameterization based on an iterative quadratic solver that is efficiently parallelizable on modern massively parallel ... Keywords: Feature detection, GPU, Mesh parameterization, Mesh segmentation, Parallel algorithms, Shape similarity object retrieval

Theodoros Athanasiadis; Ioannis Fudos

2011-06-01T23:59:59.000Z

234

Statistical delay budget partitioning in wireless mesh networks  

Science Conference Proceedings (OSTI)

Wireless Mesh Networks (WMNs) are currently attracting strong attention due to their great potential in supporting multimedia applications with real-time transport with last-mile Internet access. Multimedia end-to-end transmission requires Quality of ... Keywords: Delay budget partitioning, End-to-end QoS, IEEE 802.11s, IEEE 802.16j, Radio resource management, Wireless mesh networks

Najah A. Abu-Ali; Hossam S. Hassanein

2008-05-01T23:59:59.000Z

235

Fast adaptive elliptical filtering using box splines  

E-Print Network (OSTI)

We demonstrate that it is possible to filter an image with an elliptic window of varying size, elongation and orientation with a fixed computational cost per pixel. Our method involves the application of a suitable global pre-integrator followed by a pointwise-adaptive localization mesh. We present the basic theory for the 1D case using a B-spline formalism and then appropriately extend it to 2D using radially-uniform box splines. The size and ellipticity of these radially-uniform box splines is adaptively controlled. Moreover, they converge to Gaussians as the order increases. Finally, we present a fast and practical directional filtering algorithm that has the capability of adapting to the local image features.

Chaudhury, Kunal Narayan; Unser, Michael

2009-01-01T23:59:59.000Z

236

Gasification, polygeneration capture interest of refiners  

SciTech Connect

Integrated gasification combined cycle (IGCC) plants are moving into the mainstream of international refining. Such plants can turn refinery dregs into the whitest of all products--sparkling electricity--plus hydrogen and synthesis gas. Hydrogen is an indispensable element for cleaning up and improving modern fuels, while syngas is the feedstock for important finished petrochemicals and intermediaries. The status and potential of gasification technologies and projects were covered in a 3 day conference early in October in San Francisco. What made this conference different from others on the subject in the past was recognition that oil and natural gas producers and the international refining industry are becoming major power producers without government subsidies. Such projects can pass the scrutiny of lenders and the test of commerciality. They are not targeted simply for electricity, but also for production of hydrogen, steam, and petrochemical feedstock. The process objective for projects now far exceeds simple cogeneration. It`s now trigeneration, even polygeneration.

Aalund, L.R.

1996-12-09T23:59:59.000Z

237

Parabolic refined invariants and Macdonald polynomials  

E-Print Network (OSTI)

A string theoretic derivation is given for the conjecture of Hausel, Letellier, and Rodriguez-Villegas on the cohomology of character varieties with marked points. Their formula is identified with a refined BPS expansion in the stable pair theory of a local root stack, generalizing previous work of the first two authors in collaboration with G. Pan. Haiman's geometric construction for Macdonald polynomials is shown to emerge naturally in this context via geometric engineering. In particular this yields a new conjectural relation between Macdonald polynomials and refined local orbifold curve counting invariants. The string theoretic approach also leads to a new spectral cover construction for parabolic Higgs bundles in terms of holomorphic symplectic orbifolds.

Wu-yen Chuang; Duiliu-Emanuel Diaconescu; Ron Donagi; Tony Pantev

2013-11-14T23:59:59.000Z

238

Global refining industry preparing for future  

Science Conference Proceedings (OSTI)

About 2.1 million b/sd of crude distillation capacity is now under construction or considered likely to be built, more than 80% of which is concentrated in Asia and the Middle East. An overview of global refining centers will illustrate technological trends and the emergence of developing economies, particularly those in the Asia/Pacific region. About 50% of the refineries in the US and Western Europe have capacities greater than 200,000 b/d. Figure 1 lists the capacities and relative conversion capabilities of the world refining centers. The paper discusses bottoms conversion, regulations, investment, grassroots plans, and refinery capacities in the US, Western Europe, Eastern Europe/FSU, Middle East, Asia/Pacific region, and South America/Caribbean.

Martin, T.W. [Stone and Webster Engineering Corp., Houston, TX (United States)

1995-04-10T23:59:59.000Z

239

Genealogy of major U.S. refiners - Energy Information Administration  

U.S. Energy Information Administration (EIA) Indexed Site

See full Genealogy of Major U.S. Refiners Previous Release Genealogy of Major U.S. Refiners Genealogy of Major U.S. Refiners Release date: September 18, 2013 figre 1. World energy consumption, 1990-2040. The structure of the U.S. petroleum refining industry has changed substantially over the past several years. In the diagram the companies shown on the right side are presently active in U.S. refining. The transactions over the past 25 years that created these companies also are shown. The transactions included here may be as little as a single refinery, or as much as all the refining assets of the parties to the transaction. Transactions that include less than all refining assets are indicated by vertical dotted lines while vertical solid lines indicate that all refining assets are included. Additionally,

240

Effects of mesh density and flow conditioning in simulating 7-pin wire wrapped fuel pins.  

Science Conference Proceedings (OSTI)

In response to the goals outlined by the U.S. Department of Energy's Global Nuclear Energy Partnership program, Argonne National Laboratory has initiated an effort to create an integrated multi-physics multi-resolution thermal hydraulic simulation tool package for the evaluation of nuclear power plant design and safety. As part of this effort, the applicability of a variety of thermal hydraulic analysis methods for the prediction of heat transfer and fluid dynamics in the wire-wrapped fuel-rod bundles found in a fast reactor core is being evaluated. The work described herein provides an initial assessment of the capabilities of the general purpose commercial computational fluid dynamics code Star-CD for the prediction of fluid dynamic characteristics in a wire wrapped fast reactor fuel assembly. A 7-pin wire wrapped fuel rod assembly based on the dimensions of fuel elements in the concept Advanced Burner Test Reactor [1] was simulated for different mesh densities and domain configurations. A model considering a single axial span of the wire wrapped fuel assembly was initially used to assess mesh resolution effects. The influence of the inflow/outflow boundary conditions on the predicted flow fields in the single-span model were then investigated through comparisons with the central span region of models which included 3 and 5 spans. The change in grid refinement had minimal impact on the inter-channel exchange within the assembly resulting in roughly a 5 percent maximum difference. The central span of the 3-span and 5-span cases exhibits much higher velocities than the single span case,, with the largest deviation (15 to 20 percent) occurring furthest away from the wire spacer grids in the higher velocity regions. However, the differences between predicted flow fields in the 3-span and 5-span models are minimal.

Smith, J. G.; Babin, B. R.; Pointer, W. D.; Fischer, P. F. (Mathematics and Computer Science); ( NE); (Kansas State Univ.)

2008-01-01T23:59:59.000Z

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


241

P-12: Refinement of Primary and Eutectic Silicon Particles in ...  

Science Conference Proceedings (OSTI)

Evolution of ESR Technology and Equipment for Long Hollow Ingots Manufacture ... Phosphorus Partitioning During EAF Refining of DRI Based Steel.

242

Washington Refiner Gasoline Prices by Grade and Sales Type  

U.S. Energy Information Administration (EIA)

Refiner Gasoline Prices by Grade and Sales Type (Dollars per Gallon Excluding Taxes) ... History; Gasoline, All Grades : Through Retail Outlets: ...

243

North Carolina Refiner Gasoline Prices by Grade and Sales Type  

U.S. Energy Information Administration (EIA)

Refiner Gasoline Prices by Grade and Sales Type (Dollars per Gallon Excluding Taxes) Area: ... History; Gasoline, All Grades : Through Retail ...

244

Refining District Minnesota-Wisconsin-North Dakota-South Dakota ...  

U.S. Energy Information Administration (EIA)

Refining District Minnesota-Wisconsin-North Dakota-South Dakota Gas Plant Production of Propane and Propylene (Thousand Barrels)

245

Refining District Minnesota-Wisconsin-North Dakota-South Dakota ...  

U.S. Energy Information Administration (EIA)

Refining District Minnesota-Wisconsin-North Dakota-South Dakota Pentanes Plus Stocks at Natural Gas Processing Plants (Thousand Barrels)

246

Energy Efficiency Improvement in the Petroleum Refining Industry  

E-Print Network (OSTI)

Chemical Manufacturing and Petroleum Refining Industries.Saving Opportunities for Petroleum Refineries. An ENERGYAdministration (EIA), 2002. Petroleum Supply Annual 2001,

Worrell, Ernst; Galitsky, Christina

2005-01-01T23:59:59.000Z

247

Electron Beam Cold Hearth Refinement Processing of Inconel Alloy ...  

Science Conference Proceedings (OSTI)

ELECTRON BEAM COLD HEARTH REFINEMENT PROCESSING OF. INCONEL" ALLOY 718 AND NIMONIC* ALLOY PK50. S. Patel+,. 1-C. Elliott+,.

248

Refining District Oklahoma-Kansas-Missouri Refinery and ...  

U.S. Energy Information Administration (EIA)

Refining District Oklahoma-Kansas-Missouri Refinery and Blender Net Input of Fuel Ethanol (Thousand Barrels per Day)

249

Refining District Oklahoma-Kansas-Missouri Ethane-Ethylene ...  

U.S. Energy Information Administration (EIA)

Refining District Oklahoma-Kansas-Missouri Ethane-Ethylene Stocks at Natural Gas Processing Plants (Thousand Barrels)

250

Table 5. Refiners' Total Operable Atmospheric Crude Oil ...  

U.S. Energy Information Administration (EIA)

LYONDELL CHEMICAL CO b Houston Refining LP..... Houston, Texas...270,200 TOTAL SA Total Petrochemicals Inc ...

251

Action Refinement from a Logical Point of View  

Science Conference Proceedings (OSTI)

Action refinement provides a mechanism to design a complex reactive system hierarchically. This paper is devoted to action refinement from a logical point of view, and to combining the hierarchical implementation of a complex system with the hierarchical ... Keywords: action refinement, modal logics, reactive systems, specification, verification

Mila E. Majster-Cederbaum; Naijun Zhan; Harald Fecher

2002-01-01T23:59:59.000Z

252

Interference-aware ieee 802.16 wimax mesh networks  

E-Print Network (OSTI)

Abstract — The IEEE 802.16 WiMax standard provides a mechanism for creating multi-hop mesh, which can be deployed as a high speed wide-area wireless network. To realize the full potential of such high-speed IEEE 802.16 mesh networks, two efficient wireless radio resource allocation extensions were developed. The objective of this paper is to propose an efficient approach for increasing the utilization of WiMax mesh through appropriate design of multi-hop routing and scheduling. As multiple-access interference is a major limiting factor for wireless communication systems, we adopt here an interference-aware cross-layer design to increase the throughput of the wireless mesh network. In particular, our scheme creates a tree-based routing framework, which along with scheduling is interference aware and results in a much higher spectral efficiency. Performance evaluation results show that the proposed interference-aware scheme achieves significant throughput enhancement over the basic IEEE 802.16 mesh network.

Hung-yu Wei; Samrat Ganguly; Rauf Izmailov

2005-01-01T23:59:59.000Z

253

Towards autonomic application-sensitive partitioning for SAMR applications  

Science Conference Proceedings (OSTI)

Distributed structured adaptive mesh refinement (SAMR) techniques offer the potential for accurate and cost-effective solutions of physically realistic models of complex physical phenomena. However, the heterogeneous and dynamic nature of SAMR applications ... Keywords: autonomic partitioning, dynamic applications, runtime application characterization, structured adaptive mesh refinement

Sumir Chandra; Manish Parashar

2005-04-01T23:59:59.000Z

254

Engineering an autonomic partitioning framework for Grid-based SAMR applications  

Science Conference Proceedings (OSTI)

Dynamic structured adaptive mesh refinement (SAMR) methods for the numerical solution to partial differential equations yield highly advantageous ratios for cost/accuracy when compared to methods based upon static uniform approximations. However, distributed ... Keywords: autonomic partitioning, dynamic load balancing, grid computing, structured adaptive mesh refinement

S. Chandra; X. Li; M. Parashar

2004-01-01T23:59:59.000Z

255

Ladle Refining Furnaces for the Steel Industry  

Science Conference Proceedings (OSTI)

There has been a tremendous interest in the use of ladle refining furnaces in the last few years. Several units have been or are being constructed in the United States and most steel companies are seriously considering installing them. The purpose of this report is to inform the member companies of EPRI of the development and operations of ladle furnaces and to assist steel companies in determining if ladle furnaces fit their goals and which particular unit would be best for their operation. In this repo...

1990-01-31T23:59:59.000Z

256

Adaptive sampler  

DOE Patents (OSTI)

An adaptive data compression device for compressing data having variable frequency content, including a plurality of digital filters for analyzing the content of the data over a plurality of frequency regions, a memory, and a control logic circuit for generating a variable rate memory clock corresponding to the analyzed frequency content of the data in the frequency region and for clocking the data into the memory in response to the variable rate memory clock.

Watson, Bobby L. (Idaho Falls, ID); Aeby, Ian (Fremont, CA)

1982-01-01T23:59:59.000Z

257

Adaptive sampler  

DOE Patents (OSTI)

An adaptive data compression device for compressing data is described. The device has a frequency content, including a plurality of digital filters for analyzing the content of the data over a plurality of frequency regions, a memory, and a control logic circuit for generating a variable rate memory clock corresponding to the analyzed frequency content of the data in the frequency region and for clocking the data into the memory in response to the variable rate memory clock.

Watson, B.L.; Aeby, I.

1980-08-26T23:59:59.000Z

258

A Parallel Second-Order Adaptive Mesh Algorithm for Incompressible Flow in Porous Media  

E-Print Network (OSTI)

solving multiphase, incompressible ?ows in porous media. Wemultiphase, multicomponent incompressible ?ow in hetero- geneous porous

Pau, George Shu Heng

2009-01-01T23:59:59.000Z

259

Adaptive and deadlock-free tree-based multicast routing for networks-on-chip  

Science Conference Proceedings (OSTI)

This paper presents the first synthesizable network-on-chip (NoC) based on a mesh topology, which supports adaptive and deadlock-free tree-based multicast routing without virtual channels. The deadlock-free routing algorithms for unicast and multicast ... Keywords: network-on-chip (NoC), synchronous parallel pipeline, tree-based multicast routing, wormhole packet switching

Faizal Arya Samman; Thomas Hollstein; Manfred Glesner

2010-07-01T23:59:59.000Z

260

The Video Mesh: A Data Structure for Image-based Video Editing  

E-Print Network (OSTI)

This paper introduces the video mesh, a data structure for representing video as 2.5D "paper cutouts." The video mesh allows interactive editing of moving objects and modeling of depth, which enables 3D effects and ...

Durand, Fredo

2009-12-16T23:59:59.000Z

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


261

The Video Mesh: A Data Structure for Image-based Three-dimensional Video Editing  

E-Print Network (OSTI)

This paper introduces the video mesh, a data structure for representing video as 2.5D “paper cutouts.” The video mesh allows interactive editing of moving objects and modeling of depth, which enables 3D effects and ...

Chen, Jiawen

262

Use of a Movable Nested-Mesh Model for Tracking a Small Vortex  

Science Conference Proceedings (OSTI)

The mesh nesting strategy proposed by Kurihara et al.(1979) was used to construct a movable, nested-mesh, 11-level primitive equation model. The framework of the model is described in detail.

Yoshio Kurihara; Morris A. Bender

1980-11-01T23:59:59.000Z

263

A Conservative Mesh-Free Scheme and Generalized Framework for Conservation Laws  

E-Print Network (OSTI)

We present a novel mesh-free scheme for solving partial differential equations. We first derive a conservative and stable formulation of mesh-free first derivatives. We then show that this formulation is a special case of ...

Chiu, Edmond Kwan-Yu

264

Conversion of performance mesh animation into cage-based animation  

Science Conference Proceedings (OSTI)

Markerless highly-detailed performance capture is an emerging technology in vision-based graphics and 3D video. For instance, a framework for generating mesh animations from multi-view silhouettes is presented in [Vlasic et al. 2008]. Achieving inverse ...

Yann Savoye; Jean-Sébastien Franco

2010-12-01T23:59:59.000Z

265

Utilizing WiMAX mesh mode for efficient IPTV transmission  

Science Conference Proceedings (OSTI)

Providing high bit-rates, WiMAX enables IPTV multicasting for several simultaneous broadcasting channels. WiMAX base stations can offer higher capacity to users with better signal quality values, and more robust but lower capacity modulations to users ... Keywords: iptv, mesh mode, multicasting, wimax

Murat Ozyurt; Seckin Ulug; Tuna Tugcu

2010-10-01T23:59:59.000Z

266

Dynamic, expressive speech animation from a single mesh  

Science Conference Proceedings (OSTI)

In this work we present a method for human face animation which allows us to generate animations for a novel person given just a single mesh of their face. These animations can be of arbitrary text and may include emotional expressions. We build a multilinear ...

Kevin Wampler; Daichi Sasaki; Li Zhang; Zoran Popovi?

2007-08-01T23:59:59.000Z

267

Self-destruction procedure for mesh wireless sensor networks  

Science Conference Proceedings (OSTI)

Wireless sensor networks (WSN) are rapidly expanding their attractiveness in both military and civilian applications, imposing the need for effective security strategies/mechanisms. Since sensor networks in many circumstances operate with sensitive data ... Keywords: mesh networks, network lifecycle, security, self-destruction, wireless sensor networks

Madalin Plastoi; Daniel-Ioan Curiac; Iosif Gut; Constantin Volosencu

2009-09-01T23:59:59.000Z

268

Efficient and good Delaunay meshes from random points  

Science Conference Proceedings (OSTI)

We present a Conforming Delaunay Triangulation (CDT) algorithm based on maximal Poisson disk sampling. Points are unbiased, meaning the probability of introducing a vertex in a disk-free subregion is proportional to its area, except in a neighborhood ... Keywords: Computational geometry and topology, Computer-aided design, engineering, and manufacturing, Geophysical applications, Mesh generation, Product and assembly modeling

Mohamed S. Ebeida; Scott A. Mitchell; Andrew A. Davidson; Anjul Patney; Patrick M. Knupp; John D. Owens

2011-11-01T23:59:59.000Z

269

PubMed advanced exercise: MeSH Searching  

E-Print Network (OSTI)

achilles tendon and click Search. With MeSH searches, you enter only one search term at a time and you don can remove the need to enter multiple alternative terms to describe the same concept. For the following exercise, please search PubMed using: a) search terms that feature within the following

Rzepa, Henry S.

270

Conflict-free container routing in mesh yard layouts  

Science Conference Proceedings (OSTI)

Container terminals play an important role in global cargo transportation and they have become an essential intermodal interface between the sea and the land. In the container terminal, the service area is often arranged into rectangular blocks, which ... Keywords: Conflict-free, Container, Mesh yard layout, Number theory, Routing algorithm, Time requirement

Jianyang Zeng; Wen-Jing Hsu

2008-05-01T23:59:59.000Z

271

Renewable Energy Project Refinement Webinar | Department of Energy  

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

Renewable Energy Project Refinement Webinar Renewable Energy Project Refinement Webinar Renewable Energy Project Refinement Webinar May 28, 2014 11:00AM MDT Attendees will become familiar with the three components of project refinement: project financing strategies, off-taker agreements, and vendor selection. Project refinement obstacles, particularly financing, can deter the deployment of renewable energy projects on tribal lands. Attendees will learn about the financial resources and ownership options available-including venture capital and innovative financing-that can help Tribes overcome longstanding barriers and attract higher levels of private investment. Finally, attendees will learn how project refinement can accelerate renewable energy development and, with it, tribal economic and community development. There is no cost to attend the webinar, but

272

A CSP Account of Event-B Refinement  

E-Print Network (OSTI)

Event-B provides a flexible framework for stepwise system development via refinement. The framework supports steps for (a) refining events (one-by-one), (b) splitting events (one-by-many), and (c) introducing new events. In each of the steps events can moreover possibly be anticipated or convergent. All such steps are accompanied with precise proof obligations. Still, it remains unclear what the exact relationship - in terms of a behaviour-oriented semantics - between an Event-B machine and its refinement is. In this paper, we give a CSP account of Event-B refinement, with a treatment for the first time of splitting events and of anticipated events. To this end, we define a CSP semantics for Event-B and show how the different forms of Event-B refinement can be captured as CSP refinement.

Schneider, Steve; Wehrheim, Heike; 10.4204/EPTCS.55.9

2011-01-01T23:59:59.000Z

273

High Temperature Oxidation Behavior of Grain-refined Inconel 617 ...  

Science Conference Proceedings (OSTI)

The Cr-depleted zone of grain-refined alloy was thicker than that of the ... Intergranular Thermal Residual Strain in Rolled and Texture-free ?-Uranium.

274

Table 43. Refiner Motor Gasoline Volumes by Grade, Sales Type...  

Annual Energy Outlook 2012 (EIA)

220 Energy Information AdministrationPetroleum Marketing Annual 1998 Table 43. Refiner Motor Gasoline Volumes by Grade, Sales Type, PAD District, and State (Thousand Gallons per...

275

Table 44. Refiner Motor Gasoline Volumes by Formulation, Sales...  

Annual Energy Outlook 2012 (EIA)

250 Energy Information AdministrationPetroleum Marketing Annual 1999 Table 44. Refiner Motor Gasoline Volumes by Formulation, Sales Type, PAD District, and State (Thousand Gallons...

276

Table 31. Refiner Motor Gasoline Prices by Grade, Sales Type ...  

U.S. Energy Information Administration (EIA)

U.S. Energy Information Administration/Petroleum Marketing Monthly February 2012 76 Table 31. Refiner Motor Gasoline Prices by Grade, Sales Type, PAD District, and State

277

Renewable Energy Financial Instruments Guidance Tool (REFINe) | Open Energy  

Open Energy Info (EERE)

Renewable Energy Financial Instruments Guidance Tool (REFINe) Renewable Energy Financial Instruments Guidance Tool (REFINe) Jump to: navigation, search Tool Summary LAUNCH TOOL Name: Renewable Energy Financial Instruments Guidance Tool (REFINe) Focus Area: Renewable Energy Topics: Policy Impacts Website: web.worldbank.org/WBSITE/EXTERNAL/TOPICS/EXTENERGY2/0,,contentMDK:2298 Equivalent URI: cleanenergysolutions.org/content/renewable-energy-financial-instrument Language: English Policies: "Deployment Programs,Financial Incentives" is not in the list of possible values (Deployment Programs, Financial Incentives, Regulations) for this property. DeploymentPrograms: Training & Education Renewable Energy Financial Instruments Guidance Tool (REFINe) aims to assist policy in identifying appropriate financial instruments to scale-up

278

CATALYTIC CONVERSION OF SOLVENT REFINED COAL TO LIQUID PRODUCTS  

E-Print Network (OSTI)

and Friedman, S. ,"Conversion of Anthraxylon - Kinetics ofiv- LBL 116807 CATALYTIC CONVERSION OF SOLVENT REFINED COALand Mechanisms of Coal Conversion to Clean Fuel,iI pre-

Tanner, K.I.

2010-01-01T23:59:59.000Z

279

Effect of Sonotrode Design on Simultaneous Grain Refinement and ...  

Science Conference Proceedings (OSTI)

P-18: Phosphorus Partitioning During EAF Refining of DRI Based Steel ... P-8: Evolution of ESR Technology and Equipment for Long Hollow Ingots Manufacture.

280

Massachusetts Propane Wholesale/Resale Volume by Refiners ...  

U.S. Energy Information Administration (EIA)

Massachusetts Propane Wholesale/Resale Volume by Refiners (Thousand Gallons per Day) Decade Year-0 Year-1 Year-2 Year-3 ... No.1 and No. 2 ...

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


281

Refining District Oklahoma-Kansas-Missouri Natural Gas Liquids ...  

U.S. Energy Information Administration (EIA)

Refining District Oklahoma-Kansas-Missouri Natural Gas Liquids and Liquid Refinery Gases Stocks at Natural Gas Processing Plants (Thousand Barrels)

282

Production, Refining and Recycling of Rare Earth Metals  

Science Conference Proceedings (OSTI)

This symposium is targeting on overview of the current state of the art for production, refining and recycling of the rare earth metals. In addition the symposium is ...

283

Rising challenges for the petroleum refiners in managing corrosion ...  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, 2014 TMS Annual Meeting & Exhibition. Symposium , Materials Aspects of Corrosion and Fouling in Oil Refining and Exploration.

284

Refiner Prices of Gasoline, All Grades - Sales for Resale  

U.S. Energy Information Administration (EIA)

Refiner Gasoline Prices by Grade and Sales Type ... Download Series History: Definitions, Sources & Notes: ... Alabama: 2.759: 2.740: 2.731: ...

285

Massachusetts Refiner Gasoline Prices by Grade and Sales Type  

U.S. Energy Information Administration (EIA)

Refiner Gasoline Prices by Grade and Sales Type (Dollars per Gallon Excluding Taxes) Area: ... History; Gasoline, All Grades : Through Retail Outlets: ...

286

Refining District Minnesota-Wisconsin-North Dakota-South Dakota ...  

U.S. Energy Information Administration (EIA)

Refining District Minnesota-Wisconsin-North Dakota-South Dakota Gas Plant Production of Natural Gas Liquids and Liquid Refinery Gases (Thousand Barrels)

287

WPSR provides comprehensive crude oil and refined products ...  

U.S. Energy Information Administration (EIA)

EIA's Weekly Petroleum Status Report (WPSR) is the most comprehensive weekly data available for U.S. crude oil and refined petroleum product balances.

288

Refiners react to changes in the pipeline infrastructure  

SciTech Connect

Petroleum pipelines have long been a critical component in the distribution of crude and refined products in the U.S. Pipelines are typically the most cost efficient mode of transportation for reasonably consistent flow rates. For obvious reasons, inland refineries and consumers are much more dependent on petroleum pipelines to provide supplies of crude and refined products than refineries and consumers located on the coasts. Significant changes in U.S. distribution patterns for crude and refined products are reshaping the pipeline infrastructure and presenting challenges and opportunities for domestic refiners. These changes are discussed.

Giles, K.A. [Barnes and Click Inc., Dallas, TX (United States)

1997-06-01T23:59:59.000Z

289

Electron Beam Cold Hearth Refining of Investment Casting ...  

Science Conference Proceedings (OSTI)

Electron Beam Cold Hearth Refining of Investment Casting Superalloys in a Large Production EB Furnace. Janine C. Borofka. Axe1 Johnson Metals, Inc.

290

Neutral Oil Loss During Alkali Refining - ResearchGate  

U.S. Energy Information Administration (EIA)

Neutral Oil Loss During Alkali Refining. Albert J. Dijkstra. Journal of Oil & Fat Industries (Impact ... Experiments with cotton oil and soybean o ...

291

Studies on Refining Cobalt Salt Solution by Extraction ...  

Science Conference Proceedings (OSTI)

Cobalt sulfate solution was refined by PC88A levextrel Resins which produced from HPD-100 type of ethylene benzene -divinylbenzene porous adsorption resin  ...

292

Copper Refining Electrolyte Purification by the Use of Molecular ...  

Science Conference Proceedings (OSTI)

Presentation Title, Copper Refining Electrolyte Purification by the Use of Molecular ... An Experimental Study of Chemical Oxygen Demand Removal from the ...

293

Table 40. Refiners' Total Operable Atmospheric Crude Oil ...  

U.S. Energy Information Administration (EIA)

Table 40. Refiners' Total Operable Atmospheric Crude Oil Distillation Capacity as of January 1, 2005 Companies with Capacity Over 100,000 bbl/cd

294

Table 5. Refiners' Total Operable Atmospheric Crude Oil ...  

U.S. Energy Information Administration (EIA)

Table 5. Refiners' Total Operable Atmospheric Crude Oil Distillation Capacity as of January 1, 2006 Companies with Capacity Over 100,000 bbl/cd

295

Refining District Minnesota-Wisconsin-North Dakota-South Dakota ...  

U.S. Energy Information Administration (EIA)

Refining District Minnesota-Wisconsin-North Dakota-South Dakota Gas Plant Production of Propane and Propylene (Thousand Barrels per Day)

296

Implementation of a feature-constraint mesh generation algorithm within a GIS  

Science Conference Proceedings (OSTI)

Unstructured mesh generation has long been a labor-intensive and time-consuming aspect of hydrologic modeling. This is largely due to the iterative nature of the process and the limited integration between the specialized mesh generation software and ... Keywords: Constrained Delaunay triangulation, Discretization, Finite element, GIS, Hydrologic modeling, Mesh generation

Thomas J. Heinzer; M. Diane Williams; Emin C. Dogrul; Tariq N. Kadir; Charles F. Brush; Francis I. Chung

2012-12-01T23:59:59.000Z

297

Optimal monitoring in multi-channel multi-radio wireless mesh networks  

Science Conference Proceedings (OSTI)

Wireless mesh networks (WMN) are finding increasing usage in city-wide deployments for providing network connectivity. Mesh routers in WMNs typically use multiple wireless channels to enhance the spatial-reuse of frequency bands, often with multiple ... Keywords: approximation algorithm, lp rounding, multi-channel multi-radio wireless networks, security monitoring, wireless mesh networks

Dong-Hoon Shin; Saurabh Bagchi

2009-05-01T23:59:59.000Z

298

A systematic approach to unstructured mesh generation for ocean modelling using GMT and Terreno  

Science Conference Proceedings (OSTI)

A systematic approach to unstructured mesh generation for ocean modelling is presented. The method optimises unstructured meshes to approximate bathymetry to a user specified accuracy which may be defined as a function of longitude, latitude and bathymetry. ... Keywords: Bathymetry, Ocean modelling, Optimisation, Shoreline, Simplification, Unstructured mesh generation

G. J. Gorman; M. D. Piggott; M. R. Wells; C. C. Pain; P. A. Allison

2008-12-01T23:59:59.000Z

299

MeSH Database Articles are indexed using a powerful vocabulary,  

E-Print Network (OSTI)

the Enter key. Combine search terms with connector words: "AND", "OR" or "NOT". Type connector wordsSH). The MeSH Database provides the option of identifying appropriate MeSH terms for searches. Click on the MeSH Database link on the blue sidebar to search for a particular term or concept. After finding a term, click

Wood, James B.

300

An Evaluation of Partitioners for Parallel SAMR Applications  

Science Conference Proceedings (OSTI)

This paper presents an experimental evaluation of a suite of dynamic partitioning/load-balancing techniques for adaptive grid hierarchies that underlie parallel structured adaptive mesh refinement applications. Partitioners evaluated include those included ...

Sumir Chandra; Manish Parashar

2001-08-01T23:59:59.000Z

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


301

Extended finite element method on polygonal and quadtree meshes  

E-Print Network (OSTI)

Adaptive re?nement for B-spline ?nite element, Internationalmatrix. The application of B-spline ?nite elements [27],

Tabarraei, A.; Sukumar, N.

2008-01-01T23:59:59.000Z

302

Improving Ariadne's Bundle by Following Multiple Threads in Abstraction Refinement  

Science Conference Proceedings (OSTI)

The authors propose a scalable abstraction-refinement method for model checking invariant properties on large sequential circuits, which is based on fine-grain abstraction and simultaneous analysis of all abstract counterexamples of the shortest length. ... Keywords: Abstraction refinement, binary decision diagram (BDD), formal verification, model checking, satisfiability (SAT)

Chao Wang; Bing Li; HoonSang Jin; G. D. Hachtel; F. Somenzi

2006-11-01T23:59:59.000Z

303

Green Vegetable Oil ProcessingChapter 9 Physical Refining  

Science Conference Proceedings (OSTI)

Green Vegetable Oil Processing Chapter 9 Physical Refining Processing eChapters Processing 7E84B6524348AB59C4DF2B6D388E2582 AOCS Press Downloadable pdf of Chapter 9 Physical Refining from the book ...

304

Refining and End Use Study of Coal Liquids  

SciTech Connect

This report summarizes revisions to the design basis for the linear programing refining model that is being used in the Refining and End Use Study of Coal Liquids. This revision primarily reflects the addition of data for the upgrading of direct coal liquids.

None

1997-10-01T23:59:59.000Z

305

Augmenting Counterexample-Guided Abstraction Refinement with Proof Templates  

Science Conference Proceedings (OSTI)

Existing software model checkers based on predicate abstraction and refinement typically perform poorly at verifying the absence of buffer overflows, with analyses depending on the sizes of the arrays checked. We observe that many of these analyses can ... Keywords: safety verification, counterexample-guided abstraction refinement, proof templates, software model checkers, predicate abstraction, buffer overflows verification, array traversal idioms, PtYasm, Verisec suite

T. E. Hart; K. Ku; A. Gurfinkel; M. Chechik; D. Lie

2008-09-01T23:59:59.000Z

306

Steel refining with an electrochemical cell  

DOE Patents (OSTI)

Apparatus is described for processing a metallic fluid containing iron oxide, container for a molten metal including an electrically conductive refractory disposed for contact with the molten metal which contains iron oxide, an electrolyte in the form of a basic slag on top of the molten metal, an electrode in the container in contact with the slag electrically separated from the refractory, and means for establishing a voltage across the refractory and the electrode to reduce iron oxide to iron at the surface of the refractory in contact with the iron oxide containing fluid. A process is disclosed for refining an iron product containing not more than about 10% by weight oxygen and not more than about 10% by weight sulfur, comprising providing an electrolyte of a slag containing one or more of calcium oxide, magnesium oxide, silica or alumina, providing a cathode of the iron product in contact with the electrolyte, providing an anode in contact with the electrolyte electrically separated from the cathode, and operating an electrochemical cell formed by the anode, the cathode and the electrolyte to separate oxygen or sulfur present in the iron product therefrom. 2 figs.

Blander, M.; Cook, G.M.

1988-05-17T23:59:59.000Z

307

On the Complexity of Smooth Spline Surfaces from Quad Meshes  

E-Print Network (OSTI)

This paper derives strong relations that boundary curves of a smooth complex of patches have to obey when the patches are computed by local averaging. These relations restrict the choice of reparameterizations for geometric continuity. In particular, when one bicubic tensor-product B-spline patch is associated with each facet of a quadrilateral mesh with n-valent vertices and we do not want segments of the boundary curves forced to be linear, then the relations dictate the minimal number and multiplicity of knots: For general data, the tensor-product spline patches must have at least two internal double knots per edge to be able to model a G^1-conneced complex of C^1 splines. This lower bound on the complexity of any construction is proven to be sharp by suitably interpreting an existing surface construction. That is, we have a tight bound on the complexity of smoothing quad meshes with bicubic tensor-product B-spline patches.

Peters, Jorg

2009-01-01T23:59:59.000Z

308

A Hybrid Ring/Mesh Interconnect for Network-on-Chip Using Hierarchical Rings for Global Routing  

Science Conference Proceedings (OSTI)

A popular network topology for Network-on-Chip (NoC) implementations is the two-dimensional mesh. A disadvantage of the mesh topology is in its large communication radius. By partitioning a two-dimensional mesh into several sub-meshes and connecting ...

S. Bourduas; Z. Zilic

2007-05-01T23:59:59.000Z

309

Table 24. Refining Industry Energy Consumption  

Gasoline and Diesel Fuel Update (EIA)

- Corrections to Tables 24 to 32 - Corrections to Tables 24 to 32 Table 24. Refining Industry Energy Consumption 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2002- 2025 Carbon Dioxide Emissions 4/ (million metric tons) 190.4 185.7 188.0 191.3 207.3 215.6 220.0 222.8 225.1 226.3 228.0 230.7 234.1 237.5 238.5 239.4 239.4 238.6 240.6 240.5 242.2 244.2 245.9 246.3 246.6 1.2% Table 25. Food Industry Energy Consumption 2001 2002 2003 2004 2005 2006 2007 2008 2009 2010 2011 2012 2013 2014 2015 2016 2017 2018 2019 2020 2021 2022 2023 2024 2025 2002- 2025 Carbon Dioxide Emissions 3/ (million metric tons) 87.8 89.4 87.5 87.8 89.2 90.2 90.9 91.4 92.2 93.5 94.5 95.7 96.7 97.7 98.6 99.6 100.8 101.9 102.9 104.1 105.4 107.0 108.7 110.3 112.1 1.0% Table 26. Paper Industry Energy Consumption 2001 2002 2003 2004 2005 2006 2007

310

Changing System Interfaces Consistently: a New Refinement Strategy for CSP B  

E-Print Network (OSTI)

Changing System Interfaces Consistently: a New Refinement Strategy for CSP B Steve Schneider refinement in the context of CSP B. Our motivation to include this notion of refinement within the CSP B to change the events of a CSP process and the B machines when refining a system. Notions of refinement based

Doran, Simon J.

311

LBMD : a layer-based mesh data structure tailored for generic API infrastructures.  

SciTech Connect

A new mesh data structure is introduced for the purpose of mesh processing in Application Programming Interface (API) infrastructures. This data structure utilizes a reduced mesh representation to increase its ability to handle significantly larger meshes compared to full mesh representation. In spite of the reduced representation, each mesh entity (vertex, edge, face, and region) is represented using a unique handle, with no extra storage cost, which is a crucial requirement in most API libraries. The concept of mesh layers makes the data structure more flexible for mesh generation and mesh modification operations. This flexibility can have a favorable impact in solver based queries of finite volume and multigrid methods. The capabilities of LBMD make it even more attractive for parallel implementations using Message Passing Interface (MPI) or Graphics Processing Units (GPUs). The data structure is associated with a new classification method to relate mesh entities to their corresponding geometrical entities. The classification technique stores the related information at the node level without introducing any ambiguities. Several examples are presented to illustrate the strength of this new data structure.

Ebeida, Mohamed S.; Knupp, Patrick Michael

2010-11-01T23:59:59.000Z

312

Multi-Block Enhancement for Lagrangian Dendritic Mesh setup in Altair5  

SciTech Connect

Initial mesh setup for an ASC mUlti-physics code at LANL is done using Altair5. Altair5 assumes that the final mesh is composed of logical structured mesh blocks linked together at mesh boundaries to form, ultimately, an unstructured mesh. Within these blocks, meshes may have dendrites, that is, local regions where two zones share common edges (in two-dimensions, or faces in three-dimensions) with a single zone. In many cases, contiguous subsets of the initial set of blocks may have the same material assigned to them, but without smoothing the mesh would form a computationally challenging initial mesh. Some of these blocks may also have zones with nodes on domain boundaries. This paper reports on the implementation of multiblock smoothing in Altair5, which allows for dendrites and for moving boundary nodes. Dendritic nodes are constrained to be located at the average of their neighbor nodes while boundary nodes are constrained to move along the boundary geometry. Two fundamentally different smoothing methods were implemented. First, a variational principle is presented that balances zonal size and distortion via a user selected weighting with constraints imposed using penalty methods for dendritic nodes and Lagrange multipliers for boundary nodes. Second, the Laplace-Beltrami smoother is presented. This is a general elliptic smoother which can easily be modified to give Laplacian and Winslow-Crowley mesh smoothing. Results are shown for several test meshes of interest.

Douglass, Rodney W [Los Alamos National Laboratory

2010-12-15T23:59:59.000Z

313

Three faces of US refining: Margins by gasoline customer type  

SciTech Connect

While it is well known that the US gasoline market has become more volatile in recent years, it is less widely appreciated that the deeply structured, term-contract-oriented companies within the refining and marketing sectors are likely to obtain the best profit margins. This issue stratifies refining margins by class of wholesale-gasoline trade. This issue also presents the following: (a) ED refining netback data series for the US Gulf and West Coasts, Rotterdam, and Singapore as of September 8, 1989; and (b) ED fuel price/tax series for countries of the Western Hemisphere, September 1989 edition. 5 figs., 5 tabs.

1989-09-22T23:59:59.000Z

314

Integrated process for the solvent refining of coal  

SciTech Connect

A process is set forth for the integrated liquefaction of coal by the catalytic solvent refining of a feed coal in a first stage to liquid and solid products and the catalytic hydrogenation of the solid product in a second stage to produce additional liquid product. A fresh inexpensive, throw-away catalyst is utilized in the second stage hydrogenation of the solid product and this catalyst is recovered and recycled for catalyst duty in the solvent refining stage without any activation steps performed on the used catalyst prior to its use in the solvent refining of feed coal.

Garg, Diwakar (Macungie, PA)

1983-01-01T23:59:59.000Z

315

,"Weekly Refiner Net Production"  

U.S. Energy Information Administration (EIA) Indexed Site

Refiner Net Production" Refiner Net Production" ,"Click worksheet name or tab at bottom for data" ,"Worksheet Name","Description","# Of Series","Frequency","Latest Data for" ,"Data 1","Weekly Refiner Net Production",21,"Weekly","12/13/2013","6/4/2010" ,"Release Date:","12/18/2013" ,"Next Release Date:","12/27/2013" ,"Excel File Name:","pet_pnp_wprodr_s1_w.xls" ,"Available from Web Page:","http://www.eia.gov/dnav/pet/pet_pnp_wprodr_s1_w.htm" ,"Source:","Energy Information Administration" ,"For Help, Contact:","infoctr@eia.gov" ,,"(202) 586-8800",,,"12/18/2013 10:39:21 AM"

316

An integration of a low cost adaptive remeshing strategy in the solution of structural shape optimization problems using evolutionary methods  

Science Conference Proceedings (OSTI)

Evolutionary methods are a powerful and robust tool for the solution of structural shape optimization problems. Nevertheless, the use of these methods requires the structural analysis of an important number of different designs, this making the computational ... Keywords: Adaptive remeshing, Differential evolution, Evolutionary algorithms, Mesh optimality criteria, Sensitivity analysis, Structural shape optimization

Gabriel Bugeda; Juan José Ródenas; Eugenio Oñate

2008-07-01T23:59:59.000Z

317

2012 Short Course Edible Oils Refining Update: From the Fundamentals to New Technologies  

Science Conference Proceedings (OSTI)

Edible Oils Refining Update: From the Fundamentals to New Technologies held at the 103rd AOCS Annual Meeting and Expo. 2012 Short Course Edible Oils Refining Update: From the Fundamentals to New Technologies Edible Oils Refining Update: From the Fund

318

Secretary Bodman Tours Refinery and Calls for More Domestic Refining  

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

Tours Refinery and Calls for More Domestic Tours Refinery and Calls for More Domestic Refining Capacity Secretary Bodman Tours Refinery and Calls for More Domestic Refining Capacity May 18, 2006 - 10:43am Addthis Highlights President Bush's Four-Point Plan to Combat High Energy Prices PORT ARTHUR, TX - Secretary of Energy Samuel W. Bodman today renewed the call for expanded oil refining capacity in the United States and discussed additional steps the Department of Energy (DOE) is taking to prepare for the upcoming hurricane season. Secretary Bodman made the statements after touring the Motiva Refinery in Port Arthur, Texas. "We need a more robust energy sector; and one way to do that is to strengthen and expand our domestic oil refining capacity. We're hopeful that Motiva will continue to work to expand their capacity to 600,000

319

Developing Refined Products Storage in the Strategic Petroleum Reserve |  

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

Refined Products Storage in the Strategic Petroleum Refined Products Storage in the Strategic Petroleum Reserve Developing Refined Products Storage in the Strategic Petroleum Reserve May 12, 2009 - 3:14pm Addthis Statement of David F. Johnson, Deputy Assistant Secretary for Petroleum Reserves before the Committee on Energy and Natural Resources, United States Senate. Mr. Chairman and members of the Committee, I am pleased to be here today to discuss the issue of developing refined products storage in the Strategic Petroleum Reserve. As you know, the SPR was established by Congress through passage of the Energy Policy and Conservation Act in 1975 in response to the Arab oil embargoes. The primary policy of the U.S. petroleum stockpiling program has been to store crude oil. The SPR has served to protect our Nation from crude oil supply interruptions for over three

320

Polygons in Buildings and their Refined Side Lengths  

E-Print Network (OSTI)

1999. [Bro] K. Brown, Buildings, Springer, 1989. [BuBI] D.AMS, 2001. [D] M. Davis, Buildings are CAT(0), in “Geometryat Springerlink.com POLYGONS IN BUILDINGS AND THEIR REFINED

Kapovich, Michael; Leeb, Bernhard; Millson, John J.

2009-01-01T23:59:59.000Z

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


321

California Total Gasoline Retail Sales by Refiners (Thousand ...  

U.S. Energy Information Administration (EIA)

California Total Gasoline Retail Sales by Refiners (Thousand Gallons per Day) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6 Year-7 Year-8 Year-9; 1990's ...

322

California Propane Wholesale/Resale Volume by Refiners (Thousand ...  

U.S. Energy Information Administration (EIA)

California Propane Wholesale/Resale Volume by Refiners (Thousand Gallons per Day) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6 Year-7 Year-8 Year-9; 1980's:

323

,"U.S. Refiner Acquisition Cost of Crude Oil"  

U.S. Energy Information Administration (EIA) Indexed Site

Acquisition Cost of Crude Oil" ,"Click worksheet name or tab at bottom for data" ,"Worksheet Name","Description"," Of Series","Frequency","Latest Data for" ,"Data 1","U.S. Refiner...

324

Tennessee Propane Wholesale/Resale Volume by Refiners ...  

U.S. Energy Information Administration (EIA)

Tennessee Propane Wholesale/Resale Volume by Refiners (Thousand Gallons per Day) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 ... No.1 and No. 2 ...

325

NETL: Oil & Natural Gas Projects 00516 North Dakota Refining...  

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

the North Dakota Refining Capacity study is to assess the feasibility of increasing the oil refinery capacity in North Dakota, and, if possible, determine the scale of such an...

326

Are Refiners Entering a Golden Age or a Short Cycle?  

Reports and Publications (EIA)

A presentation exploring the factors driving higher prices, margins, and light-heavy price differentials in today's market, and what these observations may imply about future profitability in the refining industry.

Joanne Shore

2007-04-19T23:59:59.000Z

327

Basics of Edible Oil Processing and Refining Short Course  

Science Conference Proceedings (OSTI)

Organizer: Dr. Sefa Koseoglu, Filtration and Membrane World LLC, USA. This is a must for engineers, chemists, and any other technicians who want to get a good understanding of edible oil refining/processing. ...

328

Michigan Total Gasoline Retail Sales by Refiners (Thousand Gallons ...  

U.S. Energy Information Administration (EIA)

Michigan Total Gasoline Retail Sales by Refiners (Thousand Gallons per Day) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6 Year-7 Year-8 Year-9; 1990's: 3,004.6:

329

Evaluation of Electron-Beam Cold Hearth Refining (EBCHR) of ...  

Science Conference Proceedings (OSTI)

EVALUATION OF ELECTRON-BEAM COLD HEARTH REFINING (EBCHR) OF. VIRGIN AND REVERT IN738LC. P.N. Quested*, M. McLean* and M.R. Winstonet.

330

CATALYTIC CONVERSION OF SOLVENT REFINED COAL TO LIQUID PRODUCTS  

E-Print Network (OSTI)

I. Solvent Refined Coal II. Catalysts III. Purpose andSondreal, E.A. , "Viscosity of Coal Liquids - The Effect ofAnthraxylon - Kinetics of Coal Hydrogenation," Ind. and Eng.

Tanner, K.I.

2010-01-01T23:59:59.000Z

331

Data refinement in a market research applications' data production process  

Science Conference Proceedings (OSTI)

In this contribution, we will show how empirically collected field data for a market research application are refined in a stepwise manner and enriched into end-user market reports and charts. The collected data are treated by selections, transformations, ...

Thomas Ruf; Thomas Kirsche

2005-01-01T23:59:59.000Z

332

Query reformulation and refinement using NLP-based sentence clustering  

Science Conference Proceedings (OSTI)

We have developed an interactive query refinement tool that helps users search a knowledge base for solutions to problems with electronic equipment. The system is targeted towards non-technical users, who are often unable to formulate precise problem ...

Frédéric Roulland; Aaron Kaplan; Stefania Castellani; Claude Roux; Antonietta Grasso; Karin Pettersson; Jacki O'Neill

2007-04-01T23:59:59.000Z

333

Evaluation of Cold Hearth Refined Inconel Alloy 718  

Science Conference Proceedings (OSTI)

refining of superalloys. This ha8 been identified as possibly the be8t way of ... thie material involving chemical and microetructural, as we11 as cl8anliness and.

334

MODIS Cloud-Top Property Refinements for Collection 6  

Science Conference Proceedings (OSTI)

This paper summarizes the Collection-6 refinements in the Moderate Resolution Imaging Spectroradiometer (MODIS) operational cloud-top properties algorithm. The focus is on calibration improvements and on cloud macrophysical properties including ...

Bryan A. Baum; W. Paul Menzel; Richard A. Frey; David C. Tobin; Robert E. Holz; Steve A. Ackerman; Andrew K. Heidinger; Ping Yang

2012-06-01T23:59:59.000Z

335

South Dakota Gasoline Midgrade Bulk Sales (Volume) by Refiners ...  

U.S. Energy Information Administration (EIA)

South Dakota Gasoline Midgrade Bulk Sales (Volume) by Refiners (Thousand Gallons per Day) Decade Year-0 Year-1 Year-2 Year-3 Year-4 Year-5 Year-6 Year-7 Year-8 Year-9;

336

Former Corporation/Refiner Total Atmospheric Crude Oil Distillation Capacity  

U.S. Energy Information Administration (EIA) Indexed Site

Former Corporation/Refiner Former Corporation/Refiner Total Atmospheric Crude Oil Distillation Capacity (bbl/cd) New Corporation/Refiner Date of Sale Table 12. Refinery Sales During 2012 Antelope Refining LLC Garco Energy LLC 3/12 Douglas, WY 3,800 Delta Air Lines/Monroe Energy LLC ConocoPhillips Company 4/12 Trainer, PA 185,000 Phillips 66 Company ConocoPhillips Company 5/12 Belle Chasse, LA 252,000 Billings, MT 59,000 Ferndale, WA 101,000 Linden, NJ 238,000 Ponca City, OK 198,400 Rodeo, CA 120,200 Sweeny, TX 247,000 Westlake, LA 239,400 Wilmington, CA 139,000 Nustar Asphalt LLC (50% Nustar Energy LP and 50% Lindsay Goldberg LLC) Nustar Energy LP/Nustar Asphalt Refining LLC 9/12 Paulsboro, NJ 70,000 Savannah, GA 28,000 Carlyle Group/Philadelphia Energy Solutions Refining and Marketing LLC Sunoco Inc./Sunoco Inc. R&M

337

Regional differences for cost of crude oil to refiners widened in ...  

U.S. Energy Information Administration (EIA)

The cost of crude oil to refiners varies across regions based on the different types of crude oil available to refiners and transportation bottlenecks in that region.

338

Arkansas Kerosene-Type Jet Fuel Retail Sales by Refiners (Thousand ...  

U.S. Energy Information Administration (EIA)

Referring Pages: Arkansas Kerosene-Type Jet Fuel Refiner Sales Volumes; Arkansas Sales to End Users Refiner Sales Volumes of Aviation Fuels, Kerosene, Propane, No.1 ...

339

A Coarse Mesh Transport Method with general source treatment for medical physics.  

E-Print Network (OSTI)

??The Coarse-Mesh Transport Method (COMET) is a method developed by the Computational Reactor and Medical Physics Group at Georgia Tech. Its original application was neutron… (more)

Hayward, Robert M.

2009-01-01T23:59:59.000Z

340

Pamgen, a library for parallel generation of simple finite element meshes.  

SciTech Connect

Generating finite-element meshes is a serious bottleneck for large parallel simulations. When mesh generation is limited to serial machines and element counts approach a billion, this bottleneck becomes a roadblock. Pamgen is a parallel mesh generation library that allows on-the-fly scalable generation of hexahedral and quadrilateral finite element meshes for several simple geometries. It has been used to generate more that 1.1 billion elements on 17,576 processors. Pamgen generates an unstructured finite element mesh on each processor at the start of a simulation. The mesh is specified by commands passed to the library as a 'C'-programming language string. The resulting mesh geometry, topology, and communication information can then be queried through an API. pamgen allows specification of boundary condition application regions using sidesets (element faces) and nodesets (collections of nodes). It supports several simple geometry types. It has multiple alternatives for mesh grading. It has several alternatives for the initial domain decomposition. Pamgen makes it easy to change details of the finite element mesh and is very useful for performance studies and scoping calculations.

Foucar, James G.; Drake, Richard Roy; Hensinger, David M.; Gardiner, Thomas Anthony

2008-04-01T23:59:59.000Z

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


341

Investigation of several critical issues in screen mesh heat pipe manufacturing and operation.  

E-Print Network (OSTI)

??The PhD thesis with the title “Investigation of several critical issues in screen mesh heat pipe manufacturing and operation” presented hereafter describes work carried out… (more)

Engelhardt, Andreas

2010-01-01T23:59:59.000Z

342

Computation of turbulent recirculating flows using a hybrid adaptive grid  

Science Conference Proceedings (OSTI)

A hybrid adaptive gridding procedure is applied to the computation of two-dimensional turbulent, recirculating flows. The procedure combines both the local refinement method and the global moving grid method. The moving grid method is applied to obtain the initial adaptive solution. The local refinement method is then used on the large error regions flagged by using the weight function approach. The test cases are a backward facing step flow, a two-dimensional side jet flow, and an axisymmetric swirling flow. By comparing with the fine uniform grid solution, the numerical efficiencies ranging from 20 to 40 are obtained in the test problems. The most attractive feature of the procedure is its ease of application.

Lee, D.; Yeh, C.L. (National Cheng Kung Univ., Tainan (Taiwan, Province of China). Inst. of Aeronautics and Astronautics)

1994-10-01T23:59:59.000Z

343

Fictitious boundary and moving mesh methods for the numerical simulation of rigid particulate flows  

Science Conference Proceedings (OSTI)

In this paper, we investigate the numerical simulation of particulate flows using a new moving mesh method combined with the multigrid fictitious boundary method (FBM) [S. Turek, D.C. Wan, L.S. Rivkind, The fictitious boundary method for the implicit ... Keywords: ALE, FEM, Fictitious boundary, Moving mesh, Multigrid, Particulate flows

Decheng Wan; Stefan Turek

2007-03-01T23:59:59.000Z

344

Experiences in deploying a wireless mesh network testbed for traffic control  

Science Conference Proceedings (OSTI)

Wireless mesh networks (WMN) have attracted considerable interest in recent years as a convenient, flexible and low-cost alternative to wired communication infrastructures in many contexts. However, the great majority of research on metropolitan-scale ... Keywords: deployment, traffic control, wireless mesh network

Kun-chan Lan; Zhe Wang; Mahbub Hassan; Tim Moors; Rodney Berriman; Lavy Libman; Maximilian Ott; Bjorn Landfeldt; Zainab Zaidi

2007-10-01T23:59:59.000Z

345

Unbalanced Load Flow for Weakly Meshed Distribution Systems with Distributed Generation  

Science Conference Proceedings (OSTI)

Distributed Generation (DG) can bring support to distribution system, meanwhile, it bring unbalancedness in power source, load and line. Traditional load flow algorithms are not applicable to the weakly meshed distribution system with DGs. First, this ... Keywords: weakly meshed distribution system, distributed generation, unbalanced load flow, sensitivity compensation

Shao-Qiang Hu; Sen-Mao Li

2010-06-01T23:59:59.000Z

346

Solar-powered WirelessMesh Networksfor Environmental Monitoring Torsten Braun, Thomas Staub, Benjamin Nyffenegger  

E-Print Network (OSTI)

Solar-powered WirelessMesh Networksfor Environmental Monitoring Torsten Braun, Thomas Staub the development and experiencesof a solar-power driven wirelessmesh network for connectingsensorsin rural is available. II. SOLAR-POWER DRIVEN WIRELESS MESH NETWORK DEPLYOMENT AND OPERATION In a technology project

Braun, Torsten

347

Applications of WiMAX-based wireless mesh network in monitoring wind farms  

Science Conference Proceedings (OSTI)

This paper has studied the feasibility of applying World Interoperability for Microwave Access (WiMAX) based Wireless Mesh Networks (WMNs) in monitoring wind farms. WMNs provide a dynamic topology which meets the requirements of communications ... Keywords: WMNs, WiMAX, World Interoperability for Microwave Access, communications, renewable energy, simulation, wind energy, wind farm monitoring, wind farms, wind power, wireless mesh networks, wireless networks

Gang Zheng; Hongbing Xu; Xinheng Wang; Jianxiao Zou

2010-09-01T23:59:59.000Z

348

Strategies and Challenges for Interconnecting Wireless Mesh and Wireless Sensor Networks  

Science Conference Proceedings (OSTI)

Wireless sensor networks and wireless mesh networks are popular research subjects. The interconnection of both network types enables next-generation applications and creates new optimization opportunities. However, current single-gateway solutions are ... Keywords: Cooperation strategies, Future networks, Wireless mesh network, Wireless sensor network

Stefan Bouckaert; Eli De Poorter; Benôit Latré; Jeroen Hoebeke; Ingrid Moerman; Piet Demeester

2010-05-01T23:59:59.000Z

349

From silhouettes to 3D points to mesh: towards free viewpoint video  

Science Conference Proceedings (OSTI)

This paper presents a system for 3D reconstruction from video sequences acquired in multi-camera environments. In particular, the 3D surfaces of foreground objects in the scene are extracted and represented by polygon meshes. Three stages are concatenated ... Keywords: 3D scene reconstruction, kd-tree, mesh, multi-view, oriented points

Jordi Salvador; Xavier Suau; Josep R. Casas

2010-10-01T23:59:59.000Z

350

A framework for developing a mimetic tensor artificial viscosity for Lagrangian hydrocodes on arbitrary polygonal meshes  

Science Conference Proceedings (OSTI)

We construct a new mimetic tensor artificial viscosity on general polygonal meshes. The tensor artificial viscosity is based on discretization of coordinate invariant operators, divergence of a tensor and gradient of a vector. The focus of this paper ... Keywords: Artificial numerical viscosity, Lagrangian hydrodynamics, Polygonal meshes

K. Lipnikov; M. Shashkov

2010-10-01T23:59:59.000Z

351

Technical Section: CHuMI viewer: Compressive huge mesh interactive viewer  

Science Conference Proceedings (OSTI)

The preprocessing of large meshes to provide and optimize interactive visualization implies a complete reorganization that often introduces significant data growth. This is detrimental to storage and network transmission, but in the near future could ... Keywords: Interactive visualization, Large meshes, Lossless compression, Out-of-core

Clément Jamin; Pierre-Marie Gandoin; Samir Akkouche

2009-08-01T23:59:59.000Z

352

Nodes organization for channel assignment with topology preservation in multi-radio wireless mesh networks  

Science Conference Proceedings (OSTI)

The wireless mesh network is a new emerging broadband technology providing the last-mile Internet access for mobile users by exploiting the advantage of multiple radios and multiple channels. The throughput improvement of the network relies heavily on ... Keywords: Channel assignment, Multiple channels, Multiple radios, Particle swarm optimization algorithm, Wireless mesh networks

Hongju Cheng; Naixue Xiong; Athanasios V. Vasilakos; Laurence Tianruo Yang; Guolong Chen; Xiaofang Zhuang

2012-07-01T23:59:59.000Z

353

Unstructured mesh partition improvement for implicit finite element at extreme scale  

Science Conference Proceedings (OSTI)

Parallel simulations at extreme scale require that the mesh is distributed across a large number of processors with equal work load and minimum inter-part communications. A number of algorithms have been developed to meet these goals and graph/hypergraph-based ... Keywords: Extreme scale, Finite element, Partition improvement, Unstructured mesh

Min Zhou; Onkar Sahni; Ting Xie; Mark S. Shephard; Kenneth E. Jansen

2012-03-01T23:59:59.000Z

354

Efficient kinetic schemes for steady and unsteady flow simulations on unstructured meshes  

Science Conference Proceedings (OSTI)

This paper presents efficient second-order kinetic schemes on unstructured meshes for both compressible unsteady and incompressible steady flows. For compressible unsteady flows, a time-dependent gas distribution function with a discontinuous particle ... Keywords: Compressible unsteady flows, Efficient second-order kinetic schemes, Incompressible steady flows, Unstructured meshes

Guoxi Ni; Song Jiang; Kun Xu

2008-03-01T23:59:59.000Z

355

Out-of-Core Progressive Lossless Compression and Selective Decompression of Large Triangle Meshes  

Science Conference Proceedings (OSTI)

In this paper we propose a novel {\\em out-of-core} technique for{\\em progressive} lossless compression and {\\em selective}decompression of 3D triangle meshes larger than main memory. Most existing compression methods, in order to optimize compression ... Keywords: Progressive Lossless Compression, Selective Decompression, Out-of-Core Techniques, Triangle Meshes

Zhiyan Du; Pavel Jaromersky; Yi-Jen Chiang; Nasir Memon

2009-03-01T23:59:59.000Z

356

Architecture of Wireless Multimedia Mesh Network Nodes for Longwall Coal Mine Automation  

Science Conference Proceedings (OSTI)

Wireless multimedia mesh network is used for longwall coal mine face to transmit signal of data, voice and video in real time with the development of modern coal mine. The performance of the backhaul network especially it’s throughput is the essential ... Keywords: architecturet, mesh network nodes, longwall coal mine, 3-radio

Xiaolong Feng; Jiansheng Qian

2010-06-01T23:59:59.000Z

357

A reduced domain strategy for local mesh movement application in unstructured grids  

Science Conference Proceedings (OSTI)

Automatic control of mesh movement is mandatory in many fluid flow and fluid-solid interaction problems. This paper presents a new strategy, called reduced domain strategy (RDS), which enhances the efficiency of node connectivity-based mesh movement ... Keywords: Automatic grid partitioning, Grid data structure, Local grid movement or deformation, Moving boundary, Unstructured grid

Masoud Darbandi; Nematollah Fouladi

2011-09-01T23:59:59.000Z

358

On-demand unstructured mesh translation for reducing memory pressure during in situ analysis  

Science Conference Proceedings (OSTI)

When coupling two different mesh-based codes, for example with in situ analytics, the typical strategy is to explicitly copy data (deep copy) from one implementation to another, doing translation in the process. This is necessary because codes usually ... Keywords: computational meshes, in situ analysis, lazy evaluation, unstructured grids

Jonathan Woodring, James Ahrens, Timothy J. Tautges, Tom Peterka, Venkatram Vishwanath, Berk Geveci

2013-11-01T23:59:59.000Z

359

On the feasibility of the link abstraction in wireless mesh networks  

Science Conference Proceedings (OSTI)

Outdoor community mesh networks based on IEEE 802.11 have seen tremendous growth in the recent past. The current understanding is that wireless link performance in these settings is inherently unpredictable, due to multipath delay spread. Consequently, ... Keywords: IEEE 802.11, IEEE 802.15.4, WiFi, interference, link abstraction, link-level measurements, rural networks, wireless mesh networks

Bhaskaran Raman; Kameswari Chebrolu; Dattatraya Gokhale; Sayandeep Sen

2009-04-01T23:59:59.000Z

360

WiMAX-RBDS-Sim: an OPNET simulation framework for IEEE 802.16 mesh networks  

Science Conference Proceedings (OSTI)

In this paper, a simulation model for IEEE 802.16 (WiMAX) wireless mesh networks with distributed scheduling is developed. It provides a framework for the evaluation of reservation-based distributed scheduling (RBDS) policies at the medium access control ... Keywords: IEEE 802.16, OPNET, distributed scheduling, simulation, wireless mesh networks

Gustavo Vejarano; Janise McNair

2010-03-01T23:59:59.000Z

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


361

QoS differentiation for IEEE 802.16 WiMAX mesh networking  

Science Conference Proceedings (OSTI)

Recently IEEE 802.16 WiMAX has attracted a lot of attention in wireless networking research and applications. To enable a flexible and cost-effective deployment, mesh networking mode is defined in WiMAX standard. In this paper, we introduce a system ... Keywords: IEEE 802.16, QoS, WiMAX mesh, interference-aware design, scheduling

Yan Zhang; Honglin Hu; Hsiao-Hwa Chen

2008-04-01T23:59:59.000Z

362

A joint centralized scheduling and channel assignment scheme in WiMax mesh networks  

Science Conference Proceedings (OSTI)

The IEEE 802.16 standard, also known as Worldwide Interoperability for Microwave Access (WiMax), which provides a mechanism for deploying high-speed wireless mesh networks in metropolitan areas. Thus, Quality of Service (QoS) is very important for WiMax ... Keywords: MDFS algorithm, WiMax mesh networks, centralized scheduling, channel assignment

Yuliang Tang; Yan Yao; Xinrong Lin

2009-06-01T23:59:59.000Z

363

Joint optimisation for power control, scheduling and routing algorithms in the infrastructure wireless mesh network  

Science Conference Proceedings (OSTI)

The performance optimisation model for the IEEE 802.16 standard based wireless mesh network is presented and a joint optimisation method is proposed as the sub-optimal solution strategy, in which the power control, scheduling and routing algorithms ... Keywords: IEEE 80216, WMN, network throughput, performance optimisation, power control, routing, scheduling, simulation, wireless mesh networks, wireless networks

Mugen Peng; Yingjie Wang; Kun Wang; Wenbo Wang

2008-02-01T23:59:59.000Z

364

A study on distributed/centralized scheduling for wireless mesh network  

Science Conference Proceedings (OSTI)

The IEEE 802.16 standard proposes the Media Access Control (MAC) protocol for the Wireless Metropolitan Area Network (WMAN). Two transmission modes are defined in the IEEE 802.16, including Point-to-Multipoint (PMP) mode and mesh ... Keywords: 802.16, mesh, performance, scheduling, wireless

Shin-Ming Cheng; Phone Lin; Di-Wei Huang; Shun-Ren Yang

2006-07-01T23:59:59.000Z

365

Fast-converging scheduling and routing algorithms for WiMAX mesh networks  

Science Conference Proceedings (OSTI)

In this paper, we present fast converging algorithms that fit well WiMAX mesh networks. First, a centralized scheduling algorithm is presented. It calculates schedules by transforming the multi-hop tree into a single hop, and then repartitioning the ... Keywords: WiMAX, mesh networks, routing, scheduling

Salim Nahle; Naceur Malouch

2011-05-01T23:59:59.000Z

366

Experimental Adaptive Bayesian Tomography  

E-Print Network (OSTI)

We report an experimental realization of an adaptive quantum state tomography protocol. Our method takes advantage of a Bayesian approach to statistical inference and is naturally tailored for adaptive strategies. For pure states we observe close to 1/N scaling of infidelity with overall number of registered events, while best non-adaptive protocols allow for $1/\\sqrt{N}$ scaling only. Experiments are performed for polarization qubits, but the approach is readily adapted to any dimension.

Konstantin Kravtsov; Stanislav Straupe; Igor Radchenko; Neil Houlsby; Sergey Kulik

2013-03-07T23:59:59.000Z

367

Refining Crude Oil - Energy Explained, Your Guide To Understanding Energy -  

Gasoline and Diesel Fuel Update (EIA)

Oil and Petroleum Products > Refining Crude Oil Oil and Petroleum Products > Refining Crude Oil Energy Explained - Home What Is Energy? Forms of Energy Sources of Energy Laws of Energy Units and Calculators Energy Conversion Calculators British Thermal Units (Btu) Degree-Days U.S. Energy Facts State and U.S. Territory Data Use of Energy In Industry For Transportation In Homes In Commercial Buildings Efficiency and Conservation Energy and the Environment Greenhouse Gases Effect on the Climate Where Emissions Come From Outlook for Future Emissions Recycling and Energy Nonrenewable Sources Oil and Petroleum Products Refining Crude Oil Where Our Oil Comes From Imports and Exports Offshore Oil and Gas Use of Oil Prices and Outlook Oil and the Environment Gasoline Where Our Gasoline Comes From Use of Gasoline Prices and Outlook

368

Refinement and Verification of Real-Time Systems  

E-Print Network (OSTI)

This paper discusses highly general mechanisms for specifying the refinement of a real-time system as a collection of lower level parallel components that preserve the timing and functional requirements of the upper level specification. These mechanisms are discussed in the context of ASTRAL, which is a formal specification language for real-time systems. Refinement is accomplished by mapping all of the elements of an upper level specification into lower level elements that may be split among several parallel components. In addition, actions that can occur in the upper level are mapped to actions of components operating at the lower level. This allows several types of implementation strategies to be specified in a natural way, while the price for generality (in terms of complexity) is paid only when necessary. The refinement mechanisms are first illustrated using a simple digital circuit; then, through a highly complex phone system; finally, design guidelines gleaned from these specifications are presented.

Kolano, Paul Z; Kemmerer, Richard A; Mandrioli, Dino

2010-01-01T23:59:59.000Z

369

Algebraic specification and program development by stepwise refinement (Extended Abstract)  

E-Print Network (OSTI)

. Various formalizations of the concept of "refinement step" as used in the formal development of programs from algebraic specifications are presented and compared. 1 Introduction Algebraic specification aims to provide a formal basis to support the systematic development of correct programs from specifications by means of verified refinement steps. Obviously, a central piece of the puzzle is how best to formalize concepts like "specification", "program" and "refinement step". Answers are required that are simple, elegant and general and which enjoy useful properties, while at the same time taking proper account of the needs of practice. Here I will concentrate on the last of these concepts, but first I need to deal with the other two. For "program", I take the usual approach of algebraic specification whereby programs are modelled as many-sorted algebras consisting of a collection of sets of data values together with functions over those sets. This level of abstraction is commens...

Donald Sannella

1999-01-01T23:59:59.000Z

370

The US petroleum refining industry in the 1980's  

SciTech Connect

As part of the EIA program on petroleum, The US Petroleum Refining Industry in the 1980's, presents a historical analysis of the changes that took place in the US petroleum refining industry during the 1980's. It is intended to be of interest to analysts in the petroleum industry, state and federal government officials, Congress, and the general public. The report consists of six chapters and four appendices. Included is a detailed description of the major events and factors that affected the domestic refining industry during this period. Some of the changes that took place in the 1980's are the result of events that started in the 1970's. The impact of these events on US refinery configuration, operations, economics, and company ownership are examined. 23 figs., 11 tabs.

Not Available

1990-10-11T23:59:59.000Z

371

An efficient approach to unstructured mesh hydrodynamics on the cell broadband engine  

SciTech Connect

Unstructured mesh physics for the Cell Broadband Engine (CBE) has received little or no attention to date, largely because the CBE architecture poses particular challenges for unstructured mesh algorithms. The most common SPU memory management strategies cannot be applied to the irregular memory access patterns of unstructured meshes, and the SPU vector instruction set does not support the indirect addressing needed by connectivity arrays. This paper presents an approach to unstructured mesh physics that addresses these challenges, by creating a new mesh data structure and reorganizing code to give efficient CBE performance. The approach is demonstrated on the FLAG production hydrodynamics code using standard test problems, and results show an average speedup of more than 5x over the original code.

Ferenbaugh, Charles R [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

372

An efficient approach to unstructured mesh hydrodynamics on the cell broadband engine (u)  

SciTech Connect

Unstructured mesh physics for the Cell Broadband Engine (CBE) has received little or no attention to date, largely because the CBE architecture poses particular challenges for unstructured mesh algorithms. SPU memory management strategies such as data preloading cannot be applied to the irregular memory storage patterns of unstructured meshes; and the SPU vector instruction set does not support the indirect addressing needed by connectivity arrays. This paper presents an approach to unstructured mesh physics that addresses these challenges, by creating a new mesh data structure and reorganizing code to give efficient CBE performance. The approach is demonstrated on the FLAG production hydrodynamics code using standard test problems, and results show an average speedup of more than 5x over the original code.

Ferenbaugh, Charles R [Los Alamos National Laboratory

2010-12-14T23:59:59.000Z

373

THM-GTRF: New Spider meshes, New Hydra-TH runs  

SciTech Connect

Progress is reported on computational capabilities for the grid-to-rod-fretting (GTRF) problem of pressurized water reactors. Numeca's Hexpress/Hybrid mesh generator is demonstrated as an excellent alternative to generating computational meshes for complex flow geometries, such as in GTRF. Mesh assessment is carried out using standard industrial computational fluid dynamics practices. Hydra-TH, a simulation code developed at LANL for reactor thermal-hydraulics, is demonstrated on hybrid meshes, containing different element types. A series of new Hydra-TH calculations has been carried out collecting turbulence statistics. Preliminary results on the newly generated meshes are discussed; full analysis will be documented in the L3 milestone, THM.CFD.P5.05, Sept. 2012.

Bakosi, Jozsef [Los Alamos National Laboratory; Christon, Mark A. [Los Alamos National Laboratory; Francois, Marianne M. [Los Alamos National Laboratory; Lowrie, Robert B. [Los Alamos National Laboratory; Nourgaliev, Robert [Los Alamos National Laboratory

2012-06-20T23:59:59.000Z

374

Grain Refinement in TiC-Ni3Al Composites  

DOE Green Energy (OSTI)

The Cooperative Research and Development Agreement (CRADA) was to develop composites of TiC-Ni{sub 3}Al with refined grain microstructures for application in diesel engine fuel injection devices. Grain refinement is important for improved wear resistance and high strength for the applications of interest. Attrition milling effectively reduces the initial particle size and leads to a reduction of the final grain size. However, an increase in the oxygen content occurs concomitantly with the grinding operation and decreased densification of the compacts occurs during sintering.

Tiegs, T.N.

2001-01-30T23:59:59.000Z

375

National oil companies' presence to hike US refining competition  

Science Conference Proceedings (OSTI)

This paper reports that the downstream segment of the U.S. petroleum business is virtually certain to become more competitive because of the growing presence of national oil companies in the country's refining industry. That's a forecast by New York investment firm Kidder Peabody. It cites a plan by Mexico's Petroleos Mexicanos (Pemex) to form a joint venture with Shell Oil Co. covering Shell's 225,000 b/d Deer Park, Tex., refinery as the latest example of national oil companies' movement into U.S. refining.

Not Available

1992-09-21T23:59:59.000Z

376

Tangential residual as error estimator in the boundary element method  

Science Conference Proceedings (OSTI)

In this paper a new error estimator based on tangential derivative Boundary Integral Equation residuals for 2D Laplace and Helmholtz equations is shown. The direct problem for general mixed boundary conditions is solved using standard and hypersingular ... Keywords: Adaptivity, Boundary Integral Equation residual, Boundary element method, Error estimation, Mesh adaptation, Mesh refinement, Nodal sensitivity

Alejandro E. Martínez-Castro; Rafael Gallego

2005-04-01T23:59:59.000Z

377

Mesh-free simulations of shear banding in large deformation Shaofan Li, Wei Hao, Wing Kam Liu *  

E-Print Network (OSTI)

Mesh-free simulations of shear banding in large deformation Shaofan Li, Wei Hao, Wing Kam Liu Mesh-free approximation is used in numerical simulations of strain localization under large deformation. An explicit displacement based mesh-free formulation is used in both two-dimensional and three

Li, Shaofan

378

Testing for Refinement in CSP Ana Cavalcanti1  

E-Print Network (OSTI)

Testing for Refinement in CSP Ana Cavalcanti1 and Marie-Claude Gaudel2 1 University of York Abstract. CSP is a well-established formalism for modelling and verifi- cation of concurrent reactive work on algebraic reasoning and model checking. Testing techniques based on CSP models, however, have

Paris-Sud XI, Université de

379

Department of Computing Stepwise Refinement in Event-B||CSP  

E-Print Network (OSTI)

in Event-B||CSP Part 1: Safety Steve Schneider, Helen Treharne and Heike Wehrheim March 12th 2011 #12;Stepwise Refinement in Event-B CSP Part 1: Safety Steve Schneider1 Helen Treharne1 Heike Wehrheim2 1, 2011 Contents 1 Introduction 3 2 CSP 3 2.1 Notation

Doran, Simon J.

380

GRAIN REFINEMENT OF CAST URANIUM BY HEAT TREATMENT  

SciTech Connect

The thermal cycling, irradiation behavior, and fabrication characteristics of U are strongly dependent upon grain size; a smaller grain size yields the better properties. Grain refinement of cast U may be accomplished either by hot working in the high alpha temperature range or by heat treatment; refinement by the latter method was the object of this investigation. The variables studied were time, temperature, specimen size, multiple quenching, and alphaannealing after quenching. The results of the investigation have led to the following conclusions, within the scope of the experimental conditions. The grain size of cast U may be appreciably refined by beta-quenching. Time and temperature in the beta phase are not significant in determining the final alpha grain size. Multiple beta-quenches (two to four times) produce better grain size refinement than a single quench. Alpha-annealing after beta-quenching causes recrystallization, but does not greatly affect the grain size. Gamma-quenching is not recommended as a practical heat treatment. (auth)

Powell, G.W.; Klein, J.L.; Krashes, D.

1957-07-01T23:59:59.000Z

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


381

Development via refinement in probabilistic b: foundation and case study  

Science Conference Proceedings (OSTI)

In earlier work, we introduced probability to the B by providing a probabilistic choice substitution and by extending B's semantics to incorporate its meaning [8]. This, a first step, allowed probabilistic programs to be written and ... Keywords: B, generalised substitutions, probability, program correctness, randomised algorithms, refinement, weakest preconditions

Thai Son Hoang; Zhendong Jin; Ken Robinson; Annabelle McIver; Carroll Morgan

2005-04-01T23:59:59.000Z

382

Feature-oriented refinement of models, metamodels and model transformations  

Science Conference Proceedings (OSTI)

Done well, the blend of Model Driven Development (MDD) and Software Product Lines (SPL) offers a promising approach, mixing abstraction from MDD and variability from SPL. Although Model Driven Product Lines have flourished recently, the focus so far ... Keywords: AHEAD, XAK, metamodels, model transformations, modeling, models, refinements

Salvador Trujillo; Ander Zubizarreta; Xabier Mendialdua; Josune de Sosa

2009-10-01T23:59:59.000Z

383

Process for electroslag refining of uranium and uranium alloys  

DOE Patents (OSTI)

A process is described for electroslag refining of uranium and uranium alloys wherein molten uranium and uranium alloys are melted in a molten layer of a fluoride slag containing up to about 8 weight percent calcium metal. The calcium metal reduces oxides in the uranium and uranium alloys to provide them with an oxygen content of less than 100 parts per million. (auth)

Lewis, P.S. Jr.; Agee, W.A.; Bullock, J.S. IV; Condon, J.B.

1975-07-22T23:59:59.000Z

384

Energy Efficiency Improvement in the Petroleum RefiningIndustry  

Science Conference Proceedings (OSTI)

Information has proven to be an important barrier inindustrial energy efficiency improvement. Voluntary government programsaim to assist industry to improve energy efficiency by supplyinginformation on opportunities. ENERGY STAR(R) supports the development ofstrong strategic corporate energy management programs, by providingenergy management information tools and strategies. This paper summarizesENERGY STAR research conducted to develop an Energy Guide for thePetroleum Refining industry. Petroleum refining in the United States isthe largest in the world, providing inputs to virtually every economicsector, including the transport sector and the chemical industry.Refineries spend typically 50 percent of the cash operating costs (e.g.,excluding capital costs and depreciation) on energy, making energy amajor cost factor and also an important opportunity for cost reduction.The petroleum refining industry consumes about 3.1 Quads of primaryenergy, making it the single largest industrial energy user in the UnitedStates. Typically, refineries can economically improve energy efficiencyby 20 percent. The findings suggest that given available resources andtechnology, there are substantial opportunities to reduce energyconsumption cost-effectively in the petroleum refining industry whilemaintaining the quality of the products manufactured.

Worrell, Ernst; Galitsky, Christina

2005-05-01T23:59:59.000Z

385

Refining image annotation using contextual relations between words  

Science Conference Proceedings (OSTI)

In this paper, we present a probabilistic approach to refine image annotations by incorporating semantic relations between annotation words. Our approach firstly predicts a candidate set of annotation words with confidence scores. This is achieved by ... Keywords: image annotation, normalized Google distance, semantic relation

Yong Wang; Shaogang Gong

2007-07-01T23:59:59.000Z

386

Effects of Multiple Reductions on Grain Refinement During Hot ...  

Science Conference Proceedings (OSTI)

of as-cast alloy 718, a research program was initiated at the ... process design criteria for grain size refinement during primary breakdown of alloy. 718 ingot via ..... however, can and does occur during the dwell time after each strain ..... statistically ..... (1981). D. K. Matlock and D. A. Burford,. "An Experimental. Correlation.

387

Moment preserving adaptive particle weights using octree velocity distributions for PIC simulations  

SciTech Connect

The ratio of computational to physical particles is of primary concern to statistical particle based simulations such as DSMC and PIC. An adaptive computational particle weight algorithm is presented that conserves mass, momentum, and energy. This algorithm is then enhanced with an octree adaptive mesh in velocity space to mitigate artificial thermalization. The new octree merge is compared to a merge that randomly selects merge partners for a bi-Maxwellian velocity distribution. Results for crossing beams in a fixed potential well along with an electrostatic PIC version with and without MCC collisions based ionizing breakdown show the advantages of the merge algorithm to both fixed particle weights and randomly selected merge partners.

Martin, Robert Scott; Cambier, Jean-Luc [ERC Inc. (United States); Spacecraft Propulsion Branch, Air Force Research Laboratory, Edwards AFB, CA 93524 (United States)

2012-11-27T23:59:59.000Z

388

Three-dimensional gravity modeling and focusing inversion using rectangular meshes.  

SciTech Connect

Rectangular grid cells are commonly used for the geophysical modeling of gravity anomalies, owing to their flexibility in constructing complex models. The straightforward handling of cubic cells in gravity inversion algorithms allows for a flexible imposition of model regularization constraints, which are generally essential in the inversion of static potential field data. The first part of this paper provides a review of commonly used expressions for calculating the gravity of a right polygonal prism, both for gravity and gradiometry, where the formulas of Plouff and Forsberg are adapted. The formulas can be cast into general forms practical for implementation. In the second part, a weighting scheme for resolution enhancement at depth is presented. Modelling the earth using highly digitized meshes, depth weighting schemes are typically applied to the model objective functional, subject to minimizing the data misfit. The scheme proposed here involves a non-linear conjugate gradient inversion scheme with a weighting function applied to the non-linear conjugate gradient scheme's gradient vector of the objective functional. The low depth resolution due to the quick decay of the gravity kernel functions is counteracted by suppressing the search directions in the parameter space that would lead to near-surface concentrations of gravity anomalies. Further, a density parameter transformation function enabling the imposition of lower and upper bounding constraints is employed. Using synthetic data from models of varying complexity and a field data set, it is demonstrated that, given an adequate depth weighting function, the gravity inversion in the transform space can recover geologically meaningful models requiring a minimum of prior information and user interaction.

Commer, M.

2011-03-01T23:59:59.000Z

389

Microfluidic sieve using intertwined, free-standing carbon nanotube mesh as active medium  

DOE Patents (OSTI)

A microfluidic sieve having a substrate with a microfluidic channel, and a carbon nanotube mesh. The carbon nanotube mesh is formed from a plurality of intertwined free-standing carbon nanotubes which are fixedly attached within the channel for separating, concentrating, and/or filtering molecules flowed through the channel. In one embodiment, the microfluidic sieve is fabricated by providing a substrate having a microfluidic channel, and growing the intertwined free-standing carbon nanotubes from within the channel to produce the carbon nanotube mesh attached within the channel.

Bakajin, Olgica (San Leandro, CA); Noy, Aleksandr (Belmont, CA)

2007-11-06T23:59:59.000Z

390

Petascale block-structured AMR applications without distributed meta-data  

Science Conference Proceedings (OSTI)

Adaptive mesh refinement (AMR) applications to solve partial differential equations (PDE) are very challenging to scale efficiently to the petascale regime. We describe optimizations to the Chombo AMR framework that enable it to scale efficiently to ...

Brian Van Straalen; Phil Colella; Daniel T. Graves; Noel Keen

2011-08-01T23:59:59.000Z

391

A Comparison of Partitioning Schemes for Blockwise Parallel SAMR Algorithms  

Science Conference Proceedings (OSTI)

This paper presents an experimental comparison of dynamic partitioning techniques for blockwise parallel structured adaptive mesh refinement applications. A new partitioning technique, G-MISP, is described. Policies for the automatic selection of partitioner ...

Johan Steensland; Stefan Söderberg; Michael Thuné

2000-06-01T23:59:59.000Z

392

Adaptive Discrete Cosine Transform  

Science Conference Proceedings (OSTI)

The theory and performance of the adaptive discrete cosine transform filter is examined. The discrete cosine transform filter is a realization of an FIR filter as the cascade of an all-zero FIR filter with a bank of IIR digital resonators. Each bank ... Keywords: FIR filter, IIR digital resonators, LMS algorithm, adaptive discrete cosine transform filter, adaptive filters, all-zero FIR filter, filter coefficient, frequency, magnitude, phase, transfer function, update method

S. J. Bukowinski; L. Gerhardt; M. Fargues; G. Coutu

1995-10-01T23:59:59.000Z

393

Adaptive Video Retrieval  

E-Print Network (OSTI)

Hopfgartner,F. Villa,R. Urban,J. Jose,J.M. Proceedings of the First International Workshop on Adaptive Information Retrieval pp 28-29

Hopfgartner, F.

394

Surface detection, meshing and analysis during large molecular dynamics simulations  

SciTech Connect

New techniques are presented for the detection and analysis of surfaces and interfaces in atomistic simulations of solids. Atomistic and other particle-based simulations have no inherent notion of a surface, only atomic positions and interactions. The algorithms we introduce here provide an unambiguous means to determine which atoms constitute the surface, and the list of surface atoms and a tessellation (meshing) of the surface are determined simultaneously. The algorithms have been implemented and demonstrated to run automatically (on the fly) in a large-scale parallel molecular dynamics (MD) code on a supercomputer. We demonstrate the validity of the method in three applications in which the surfaces and interfaces evolve: void surfaces in ductile fracture, the surface morphology due to significant plastic deformation of a nanoscale metal plate, and the interfaces (grain boundaries) and void surfaces in a nanoscale polycrystalline system undergoing ductile failure. The technique is found to be quite robust, even when the topology of the surfaces changes as in the case of void coalescence where two surfaces merge into one. It is found to add negligible computational overhead to an MD code, and is much less expensive than other techniques such as the solvent-accessible surface.

Dupuy, L M; Rudd, R E

2005-08-01T23:59:59.000Z

395

Simple yet efficient, transparent airtime allocation for TCP in wireless mesh networks  

Science Conference Proceedings (OSTI)

In this paper, we explore a simple yet effective technique for explicitly allocating airtime to each active pair of communicating neighbors in a wireless neighborhood so that TCP starvation in a wireless mesh network is avoided. Our explicit allocation ...

Ki-Young Jang; Konstantinos Psounis; Ramesh Govindan

2010-11-01T23:59:59.000Z

396

Prediction Experiments of Hurricane Gloria (1985) Using a Multiply Nested Movable Mesh Model  

Science Conference Proceedings (OSTI)

The prediction capability of the GFDL triply nested, movable mesh model, with finest grid resolution of degree, was investigated using several case studies of Hurricane Gloria ( 1985) during the period that the storm approached and moved up the ...

Yoshio Kurihara; Morris A. Bender; Robert E. Tuleya; Rebecca J. Ross

1990-10-01T23:59:59.000Z

397

Achieving True Video-on-Demand Service in Multi-Hop WiMax Mesh Networks  

E-Print Network (OSTI)

Mesh Network Configuration (MSH-NCFG) messages. Each MSH-NCFG message contains a Network Descriptor by listening to MSH-NCFG messages. From all the possible neighboring nodes that advertise MSH-NCFG messages

Hua, Kien A.

398

Margin turnaround at hand: reprieve for US refiners  

SciTech Connect

After unseasonal US gasoline price deterioration during the summer driving months, a turnaround in rack (unbranded, undelivered wholesale) prices is helping to reverse the downward trend in refining margins on the Gulf Coast. In turn, the improved margins are buoying up light crude oil prices in the US Gulf Coast and strengthening spot-market prices. A graph tracks apparent margins on four important crudes utilized on the US Gulf Coast. August 1984 saw negative margins even for heavy Venezuelan Lagunillas (15/sup 0/ API) and Mexican Maya (22/sup 0/ API), but both were again positive in September. Energy Detente refining netback data for September 1984 are presented for the US Gulf Coast, the US West Coast, Rotterdam, and Singapore. The fuel price/tax series and industrial fuel prices are presented for September 1984 for countries of the Western Hemisphere.

1984-09-26T23:59:59.000Z

399

Atlantic Basin Refining Dynamics from U.S. Perspective  

Gasoline and Diesel Fuel Update (EIA)

“This presentation focuses on the current refining situation in the Atlantic Basin, “This presentation focuses on the current refining situation in the Atlantic Basin, Page 1 including some discussion on how we got here, and on drivers that will influence the next 5 years. I will focus on three topics today that are critical to the petroleum product dynamics of Page 2 the Atlantic Basin over the next several years. The first is product demand growth - something that has been affected both by the recession and legislation. Next I will cover the supply situation for gasoline and distillates in the Atlantic Basin, since Europe and the U.S. are closely entwined in these markets. Last, we will visit the outlook for those drivers affecting profitability - an area of large uncertainty. I will begin today with a short discussion of important underlying long-term trends in U.S.

400

Post-refinement multiscale method for pin power reconstruction  

SciTech Connect

The ability to accurately predict local pin powers in nuclear reactors is necessary to understand the mechanisms that cause fuel pin failure during steady state and transient operation. In the research presented here, methods are developed to improve the local solution using high order methods with boundary conditions from a low order global solution. Several different core configurations were tested to determine the improvement in the local pin powers compared to the standard techniques based on diffusion theory and pin power reconstruction (PPR). The post-refinement multiscale methods use the global solution to determine boundary conditions for the local solution. The local solution is solved using either a fixed boundary source or an albedo boundary condition; this solution is 'post-refinement' and thus has no impact on the global solution. (authors)

Collins, B.; Seker, V.; Downar, T. [Dept. of Nuclear Engineering and Radiological Sciences, Univ. of Michigan, 2355 Bonisteel Blvd., Ann Arbor, MI 48109 (United States); Xu, Y. [Argonne National Laboratory (United States)

2012-07-01T23:59:59.000Z

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


401

Refiner details ``best practices`` approach to catalyst selection  

Science Conference Proceedings (OSTI)

Catalysts are critical to hydrocarbon processing in refineries. Refiners spend millions of dollars per year on catalysts. This cost, however, pales in comparison to the impact that catalysts can have. The lost opportunity from not using the right catalyst, or an unscheduled shutdown caused by a catalyst-related problem, can be an order of magnitude higher than the cost of the catalyst itself. Chevron Products Co. has adopted a best practices approach to addressing technical and operational issues in refining. A subset of the best-practices program includes the testing, selection, and monitoring of catalysts for Chevron`s fluid catalytic cracking (FCC), catalytic reforming, and hydroprocessing units. The paper discusses these practices.

Krishna, A.S. [Chevron Products Co., El Segundo, CA (United States); Arndt, J.H. [Chevron Products Co., Richmond, CA (United States); Kuehler, C.W.; Kramer, D.C. [Chevron Research and Technology Co., Richmond, CA (United States)

1996-10-14T23:59:59.000Z

402

Engineering and Biological Assessment of Fine Mesh Fish Protection-Modified Traveling Water Screens  

Science Conference Proceedings (OSTI)

This report describes the results of a study that examined: (1) the protection afforded to early life stages (eggs, larvae, and juveniles) of fish and shellfish by different traveling water screen (TWS) mesh sizes and (2) the engineering challenges, operational and maintenance (O&M) issues, and installation costs that power plants may experience if fine-mesh modified TWSs are identified as a site-specific best technology available (BTA) for minimizing entrainment mortality in accordance with a ...

2013-05-08T23:59:59.000Z

403

Changing Trends in the Refining Industry (released in AEO2006)  

Reports and Publications (EIA)

There have been some major changes in the U.S. refining industry recently, prompted in part by a significant decline in the quality of imported crude oil and by increasing restrictions on the quality of finished products. As a result, high-quality crudes, such as the WTI crude that serves as a benchmark for oil futures on the New York Mercantile Exchange (NYMEX), have been trading at record premiums to the OPEC Basket price.

Information Center

2006-02-01T23:59:59.000Z

404

REFINING AND END USE STUDY OF COAL LIQUIDS  

DOE Green Energy (OSTI)

This document summarizes all of the work conducted as part of the Refining and End Use Study of Coal Liquids. There were several distinct objectives set, as the study developed over time: (1) Demonstration of a Refinery Accepting Coal Liquids; (2) Emissions Screening of Indirect Diesel; (3) Biomass Gasification F-T Modeling; and (4) Updated Gas to Liquids (GTL) Baseline Design/Economic Study.

Unknown

2002-01-01T23:59:59.000Z

405

2011 Short CourseNew Technologies in Oilseed Extraction and Edible Oil Refining  

Science Conference Proceedings (OSTI)

New Technologies in Oilseed Extraction and Edible Oil Refining ShortCourse held at the 102nd AOCS Annual Meeting and Expo. 2011 Short CourseNew Technologies in Oilseed Extraction and Edible Oil Refining New Technologies in Oilseed Extraction

406

2010 Short Course New Technologies in Oilseed Extraction and Edible Oil Refining  

Science Conference Proceedings (OSTI)

New Technologies in Oilseed Extraction and Edible Oil Refining Short Course held at the 101st AOCS Annual Meeting and Expo. 2010 Short Course New Technologies in Oilseed Extraction and Edible Oil Refining New Technologies in Oilseed Extraction and

407

Hydrogen and Fuel Cells - Refining the Message Initiating a National Dialogue and Educational Agenda  

E-Print Network (OSTI)

Hydrogen and Fuel Cells – Refining the Message Initiating aApril 1, 2005 Hydrogen and Fuel Cells – Refining the Message2002, "Fuel Choices for Fuel Cell Vehicles: Well-to-Wheels

Eggert, Anthony; Kurani, Kenneth S; Turrentine, Tom; Ogden, Joan M; Sperling, Dan; Winston, Emily

2005-01-01T23:59:59.000Z

408

Superior refining performance beyond 2000 -- Breaking traditional paradigms  

SciTech Connect

Over the last 5 years, refining companies have not performed well financially, generating returns below the cost of capital. Environmental regulations have caused the industry to invest significant amounts of capital, and while new regulations will cause the shutdown of between 500 thousand and 1.2 million barrels per day of capacity, the industry structure will remain poor and financial returns for the average player will likely be volatile, cyclical, and below the cost of capital. Based on this industry outlook, refining companies seeking superior performance will have to break the traditional paradigms and adopt world-class practices used in other industries. Changes required to significantly improve financial returns will include shifts in business strategy to accommodate growth, and development of nontraditional services, as well as initiates to dramatically reshape cost structure and improve profitability. Making the changes to become a superior performer in the refining business will require a clear vision and strong leadership at multiple levels in the organization. The transformation will also require changes in company culture and incentive plans that encourage managers to act as owners. In addition, superior performers will push accountability for results to low levels in the organization. Given the herd mentality of the oil industry, superior performers must take decisive, preemptive action to generate a substantial, competitive advantage.

Tassel, B. van [McKinsey and Co., Inc., Houston, TX (United States)

1995-09-01T23:59:59.000Z

409

Decontamination of steel by melt refining: A literature review  

SciTech Connect

It has been reported that a large amount of metal waste is produced annually by nuclear fuel processing and nuclear power plants. These metal wastes are contaminated with radioactive elements, such as uranium and plutonium. Current Department of Energy guidelines require retrievable storage of all metallic wastes containing transuranic elements above a certain level. Because of high cost, it is important to develop an effective decontamination and volume reduction method for low level contaminated metals. It has been shown by some investigators that a melt refining technique can be used for the processing of the contaminated metal wastes. In this process, contaminated metal is melted wit a suitable flux. The radioactive elements are oxidized and transferred to a slag phase. In order to develop a commercial process it is important to have information on the thermodynamics and kinetics of the removal. Therefore, a literature search was carried out to evaluate the available information on the decontamination uranium and transuranic-contaminated plain steel, copper and stainless steel by melt a refining technique. Emphasis was given to the thermodynamics and kinetics of the removal. Data published in the literature indicate that it is possible to reduce the concentration of radioactive elements to a very low level by the melt refining method. 20 refs.

Ozturk, B.; Fruehan, R.J. [Carnegie-Mellon Univ., Pittsburgh, PA (United States)

1994-12-31T23:59:59.000Z

410

Connectivity-based, all-hexahedral mesh generation method and apparatus  

DOE Patents (OSTI)

The present invention is a computer-based method and apparatus for constructing all-hexahedral finite element meshes for finite element analysis. The present invention begins with a three-dimensional geometry and an all-quadrilateral surface mesh, then constructs hexahedral element connectivity from the outer boundary inward, and then resolves invalid connectivity. The result of the present invention is a complete representation of hex mesh connectivity only; actual mesh node locations are determined later. The basic method of the present invention comprises the step of forming hexahedral elements by making crossings of entities referred to as ``whisker chords.`` This step, combined with a seaming operation in space, is shown to be sufficient for meshing simple block problems. Entities that appear when meshing more complex geometries, namely blind chords, merged sheets, and self-intersecting chords, are described. A method for detecting invalid connectivity in space, based on repeated edges, is also described, along with its application to various cases of invalid connectivity introduced and resolved by the method. 79 figs.

Tautges, T.J.; Mitchell, S.A.; Blacker, T.D.; Murdoch, P.

1998-06-16T23:59:59.000Z

411

Connectivity-based, all-hexahedral mesh generation method and apparatus  

DOE Patents (OSTI)

The present invention is a computer-based method and apparatus for constructing all-hexahedral finite element meshes for finite element analysis. The present invention begins with a three-dimensional geometry and an all-quadrilateral surface mesh, then constructs hexahedral element connectivity from the outer boundary inward, and then resolves invalid connectivity. The result of the present invention is a complete representation of hex mesh connectivity only; actual mesh node locations are determined later. The basic method of the present invention comprises the step of forming hexahedral elements by making crossings of entities referred to as "whisker chords." This step, combined with a seaming operation in space, is shown to be sufficient for meshing simple block problems. Entities that appear when meshing more complex geometries, namely blind chords, merged sheets, and self-intersecting chords, are described. A method for detecting invalid connectivity in space, based on repeated edges, is also described, along with its application to various cases of invalid connectivity introduced and resolved by the method.

Tautges, Timothy James (Albuquerque, NM); Mitchell, Scott A. (Albuquerque, NM); Blacker, Ted D. (Green Oaks, IL); Murdoch, Peter (Salt Lake City, UT)

1998-01-01T23:59:59.000Z

412

Physical Simulation of an Embedded Surface Mesh Involving Deformation and Fracture  

E-Print Network (OSTI)

Simulating virtual objects which can deform or break apart within their environments is now common in state-of-the-art virtual simulations such as video games or surgery simulations. Real-time performance requires a physical model which provides an approximation to the true solution for fast computations but at the same time provides enough believability of the simulation to the user. Recent research in object deformation and fracture has revolved around embedding portions of the simulation for graphical display inside a much simpler physical domain which is invisible to the user. Embedding complex geometry in a simpler domain allows for very complex effects to occur in a much more robust and computationally efficient manner. This thesis explores a novel method to efficiently embed a high-resolution surface mesh inside a coarse tetrahedral physical mesh for the purposes of interactive simulation and display. A technique to display interior regions as solid geometry without explicitly re-meshing the graphical mesh during fracture has been explored and developed. Keeping the graphical mesh static in memory during simulation allows the geometry to be off-loaded to the GPU while shaders can be utilized to only display portions of the geometry which are locally contained within the physical mesh. Recent advances in GPU technology have also been exploited in order to provide an increase in visual fidelity and help achieve the illusion that the virtual object itself is breaking apart in a physically plausible manner.

Clack, Billy

2012-05-01T23:59:59.000Z

413

Weekly U.S. Refiner and Blender Adjusted Net Production of ...  

U.S. Energy Information Administration (EIA)

Weekly U.S. Refiner and Blender Adjusted Net Production of Finished Motor Gasoline (Thousand Barrels per Day)

414

Effects of Feed Quality and Product Specification Changes on Refined Product Supply  

Reports and Publications (EIA)

The presentation explores the implications that future feedstock changes and product specification changes may have on refined product supply.

Information Center

2003-03-01T23:59:59.000Z

415

Weekly U.S. Refiner, Blender, and Gas Plant Net Production of ...  

U.S. Energy Information Administration (EIA)

Weekly U.S. Refiner, Blender, and Gas Plant Net Production of Propane and Propylene (Thousand Barrels per Day)

416

Proceedings of the IASTED International Conference Parallel and Distributed Computing and Systems  

E-Print Network (OSTI)

Distribution and Load-Balancing Techniques for Adaptive Grid Hierarchies Mausumi Shee, Samip Bhavsar characterization and evaluation of dynamic partitioning and load-balancing techniques for distributed adaptive grid-balancing techniques for distributed adaptive grid hierarchies that underlie parallel adaptive mesh- refinement (AMR

Parashar, Manish

417

Refinement and verification of concurrent systems specified in ObjectZ and CSP  

E-Print Network (OSTI)

Refinement and verification of concurrent systems specified in Object­Z and CSP Graeme Smith­Z and CSP. A common semantic basis for the two languages enables a unified method of refinement to be used, based upon CSP refinement. To enable state­based techniques to be used for the Object­Z components

Smith, Graeme

418

Retrenching the Purse: The Balance Enquiry Quandary, and Generalised and (1,1) Forward Refinements  

Science Conference Proceedings (OSTI)

Some of the success stories of model based refinement are recalled, as well as some of the annoyances that arise when refinement is deployed in the engineering of large systems. The way that retrenchment attempts to alleviate such inconveniences is briefly ... Keywords: Atomicity, Mondex Purse, Refinement, Retrenchment, Verification

Richard Banach; Czeslaw Jeske; Michael Poppleton; Susan Stepney

2007-01-01T23:59:59.000Z

419

Retrenching the Purse: The Balance Enquiry Quandary, and Generalised and (1,1) Forward Refinements  

Science Conference Proceedings (OSTI)

Some of the success stories of model based refinement are recalled, as well as some of the annoyances that arise when refinement is deployed in the engineering of large systems. The way that retrenchment attempts to alleviate such inconveniences is briefly ... Keywords: Atomicity, Mondex Purse, Refinement, Retrenchment, Verification

Richard Banach; Czeslaw Jeske; Michael Poppleton; Susan Stepney

2007-05-01T23:59:59.000Z

420

A performance study of data layout techniques for improving data locality in refinement-based pathfinding  

Science Conference Proceedings (OSTI)

The widening gap between processor speed and memory latency increases the importance of crafting data structures and algorithms to exploit temporal and spatial locality. Refinement-based pathfinding algorithms, such as Classic Refinement (CR), find quality ... Keywords: Cache-conscious algorithms, classical refinement, pathfinding

Robert Niewiadomski; José Nelson Amaral; Robert C. Holte

2004-12-01T23:59:59.000Z

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


421

Parallel Adaptive Simulation of Weak and Strong Transverse-Wave Structures in H2-O2 Detonations  

DOE Green Energy (OSTI)

Two- and three-dimensional simulation results are presented that investigate at great detail the temporal evolution of Mach reflection sub-structure patterns intrinsic to gaseous detonation waves. High local resolution is achieved by utilizing a distributed memory parallel shock-capturing finite volume code that employs block-structured dynamic mesh adaptation. The computational approach, the implemented parallelization strategy, and the software design are discussed.

Deiterding, Ralf [ORNL

2010-01-01T23:59:59.000Z

422

Leak test adapter for containers  

DOE Patents (OSTI)

An adapter is provided for facilitating the charging of containers and leak testing penetration areas. The adapter comprises an adapter body and stem which are secured to the container`s penetration areas. The container is then pressurized with a tracer gas. Manipulating the adapter stem installs a penetration plug allowing the adapter to be removed and the penetration to be leak tested with a mass spectrometer. Additionally, a method is provided for using the adapter. The present invention relates generally to leak test adapters, and more particularly to leak test adapters used with containers such as radioactive material shipping containers.

Hallett, B.H.; Hartley, M.S.

1995-12-31T23:59:59.000Z

423

Optical Military Systems Adaptive  

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

turbulence in ground-based telescopes or to improve the spatial mode and power of lasers. More recently, Sandia has led the innovation of using adaptive elements, such as...

424

The Climate Adaptation Frontier  

Science Conference Proceedings (OSTI)

Climate adaptation has emerged as a mainstream risk management strategy for assisting in maintaining socio-ecological systems within the boundaries of a safe operating space. Yet, there are limits to the ability of systems to adapt. Here, we introduce the concept of an adaptation frontier , which is defined as a socio-ecological system s transitional adaptive operating space between safe and unsafe domains. A number of driving forces are responsible for determining the sustainability of systems on the frontier. These include path dependence, adaptation/development deficits, values conflicts and discounting of future loss and damage. The cumulative implications of these driving forces are highly uncertain. Nevertheless, the fact that a broad range of systems already persist at the edge of their frontiers suggests a high likelihood that some limits will eventually be exceeded. The resulting system transformation is likely to manifest as anticipatory modification of management objectives or loss and damage. These outcomes vary significantly with respect to their ethical implications. Successful navigation of the adaptation frontier will necessitate new paradigms of risk governance to elicit knowledge that encourages reflexive reevaluation of societal values that enable or constrain sustainability.

Preston, Benjamin L [ORNL

2013-01-01T23:59:59.000Z

425

Cogeneration handbook for the petroleum refining industry. [Contains glossary  

SciTech Connect

The decision of whether to cogenerate involves several considerations, including technical, economic, environmental, legal, and regulatory issues. Each of these issues is addressed separately in this handbook. In addition, a chapter is included on preparing a three-phase work statement, which is needed to guide the design of a cogeneration system. In addition, an annotated bibliography and a glossary of terminology are provided. Appendix A provides an energy-use profile of the petroleum refining industry. Appendices B through O provide specific information that will be called out in subsequent chapters.

Fassbender, L.L.; Garrett-Price, B.A.; Moore, N.L.; Fassbender, A.G.; Eakin, D.E.; Gorges, H.A.

1984-03-01T23:59:59.000Z

426

Minimally refined biomass fuel. [carbohydrate-water-alcohol mixture  

DOE Patents (OSTI)

A minimally refined fluid composition, suitable as a fuel mixture and derived from biomass material, is comprised of one or more water-soluble carbohydrates such as sucrose, one or more alcohols having less than four carbons, and water. The carbohydrate provides the fuel source; water-solubilizes the carbohydrate; and the alcohol aids in the combustion of the carbohydrate and reduces the viscosity of the carbohydrate/water solution. Because less energy is required to obtain the carbohydrate from the raw biomass than alcohol, an overall energy savings is realized compared to fuels employing alcohol as the primary fuel.

Pearson, R.K.; Hirschfeld, T.B.

1981-03-26T23:59:59.000Z

427

Bethe roots and refined enumeration of alternating-sign matrices  

E-Print Network (OSTI)

The properties of the most probable ground state candidate for the XXZ spin chain with the anisotropy parameter equal to -1/2 and an odd number of sites is considered. Some linear combinations of the components of the considered state, divided by the maximal component, coincide with the elementary symmetric polynomials in the corresponding Bethe roots. It is proved that those polynomials are equal to the numbers providing the refined enumeration of the alternating-sign matrices of order M+1 divided by the total number of the alternating-sign matrices of order M, for the chain of length 2M+1.

A. V. Razumov; Yu. G. Stroganov

2006-05-01T23:59:59.000Z

428

Sleep and Wakeup Strategies in Solar-Powered Wireless Sensor/Mesh Networks: Performance Analysis and Optimization  

Science Conference Proceedings (OSTI)

A queuing analytical model is presented to investigate the performances of different sleep and wakeup strategies in a solar-powered wireless sensor/mesh network where a solar cell is used to charge the battery in a sensor/mesh node. While the solar radiation ... Keywords: Solar-powered wireless sensor/mesh networks, sleep and wakeup strategies, queuing analysis, system utility, game theory.

Dusit Niyato; Ekram Hossain; Afshin Fallahi

2007-02-01T23:59:59.000Z

429

Multi-channel transmission with efficient delivery of routing information in maritime WiMAX mesh networks  

Science Conference Proceedings (OSTI)

There is a lack of broadband wireless network in sea to meet the increasing needs of modern maritime users and we have envisaged WiMAX mesh networks for high-speed and low-cost ship-to-ship/shore communications. In such a maritime WiMAX mesh network, ... Keywords: IEEE Std 802.16-2004, broadband wireless access, maritime communications, mesh network, multi-channel transmission

Ming-Tuo Zhou; Hiroshi Harada; Peng-Yong Kong; Chee-Wei Ang; Yu Ge; J. S. Pathmasuntharam

2009-06-01T23:59:59.000Z

430

Method for generating a mesh representation of a region characterized by a trunk and a branch thereon  

DOE Patents (OSTI)

The present invention provides a meshing method, called grafting, that lifts the prior art constraint on abutting surfaces, including surfaces that are linking, source/target, or other types of surfaces of the trunk volume. The grafting method locally modifies the structured mesh of the linking surfaces allowing the mesh to conform to additional surface features. Thus, the grafting method can provide a transition between multiple sweep directions extending sweeping algorithms to 23/4-D solids. The method is also suitable for use with non-sweepable volumes; the method provides a transition between meshes generated by methods other than sweeping as well.

Shepherd, Jason (Albuquerque, NM); Mitchell, Scott A. (Albuquerque, NM); Jankovich, Steven R. (Anaheim, CA); Benzley, Steven E. (Provo, UT)

2007-05-15T23:59:59.000Z

431

Verification of Unstructured Mesh Capabilities in MCNP6 for Reactor Physics Problems  

SciTech Connect

New unstructured mesh capabilities in MCNP6 (developmental version during summer 2012) show potential for conducting multi-physics analyses by coupling MCNP to a finite element solver such as Abaqus/CAE[2]. Before these new capabilities can be utilized, the ability of MCNP to accurately estimate eigenvalues and pin powers using an unstructured mesh must first be verified. Previous work to verify the unstructured mesh capabilities in MCNP was accomplished using the Godiva sphere [1], and this work attempts to build on that. To accomplish this, a criticality benchmark and a fuel assembly benchmark were used for calculations in MCNP using both the Constructive Solid Geometry (CSG) native to MCNP and the unstructured mesh geometry generated using Abaqus/CAE. The Big Ten criticality benchmark [3] was modeled due to its geometry being similar to that of a reactor fuel pin. The C5G7 3-D Mixed Oxide (MOX) Fuel Assembly Benchmark [4] was modeled to test the unstructured mesh capabilities on a reactor-type problem.

Burke, Timothy P. [Los Alamos National Laboratory; Martz, Roger L. [Los Alamos National Laboratory; Kiedrowski, Brian C. [Los Alamos National Laboratory; Martin, William R. [Los Alamos National Laboratory

2012-08-22T23:59:59.000Z

432

Process Refinements - Reporting of Public Use of Diesel Fuel  

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

Based on FHWA's reassessment of the reporting and attribution process and on the GAO study, several specific issues were identified. These issues were published in a Federal Register notice for public response.3 Sixteen States provided comments on the issues provided in the Federal Register. Two additional issues were also raised by commenters. The comments may be found at http://dmses.dot.gov; search for docket number FHWA-2000-7635. All of the issues are discussed below. Certain process refinements are required to address these issues; these changes are explained in the following sections. Based on FHWA's reassessment of the reporting and attribution process and on the GAO study, several specific issues were identified. These issues were published in a Federal Register notice for public response.3 Sixteen States provided comments on the issues provided in the Federal Register. Two additional issues were also raised by commenters. The comments may be found at http://dmses.dot.gov; search for docket number FHWA-2000-7635. All of the issues are discussed below. Certain process refinements are required to address these issues; these changes are explained in the following sections. Some of the issues concern the data reported by the States. Because of differences in State laws, States collect different types of data. Chapter 2 of A Guide to Reporting Highway Statistics4 provides instructions for completing Forms FHWA-551M and FHWA-556.

433

Experimental evaluation of a metal-mesh bearing damper in a high speed test rig  

E-Print Network (OSTI)

Metal mesh is a commercially available material used in many applications including seals, heat shields, filters, gaskets, aircraft engine mounts, and vibration absorbers. This material has been tested in the Turbomachinery Laboratory at Texas A&M University (TAMU) as a bearing damper in a rotordynamic test rig. The test facility was originally used to support the design of a turboprop engine at TAMU, developing squirrel cage bearing supports and squeeze film dampers for both the gas generator and power turbine rotors. To design the metal mesh damper, static stiffness and dynamic rap test measurements were first made on metal mesh samples in a specially designed non-rotating test fixture. These property tests were performed on samples of various densities and press fits. One sample was also tested in an Instron machine as an ancillary and redundant way to determine the stiffness. Using the stiffness test results and equations derived by a previous investigator, a spreadsheet program was written and used to size metal mesh donuts that have the radial stiffness value required to replace the squirrel cage in the power turbine. The squirrel cage and squeeze-film bearing damper developed for the power turbine rotor was then replaced by a metal mesh donut sized by the computer code. Coast-down tests were conducted through the first critical speed of the power turbine. The results of the metal mesh tests were compared with those obtained from previous testing with the squeeze film damper. The results show that the metal mesh damper has the same damping as the squeeze film at room temperature but does not lose its damping at elevated temperatures up to 210F?. Experiments were run under several different conditions including balanced rotor hot oil soaked, unbalanced rotor hot oil soaked, balanced dry, and unbalanced dry. Over all, metal mesh dampers appear to be a viable and attractive substitute for squeeze film dampers in gas turbine engines. The advantages shown to date include less variation of damping with temperature, ability to handle large rotor unbalance, and the ability (if required) to operate effectively in an oil free environment.

Zarzour, Mark Joseph

1999-01-01T23:59:59.000Z

434

Verification of Adaptive Systems  

SciTech Connect

Adaptive systems are critical for future space and other unmanned and intelligent systems. Verification of these systems is also critical for their use in systems with potential harm to human life or with large financial investments. Due to their nondeterministic nature and extremely large state space, current methods for verification of software systems are not adequate to provide a high level of assurance for them. The combination of stabilization science, high performance computing simulations, compositional verification and traditional verification techniques, plus operational monitors, provides a complete approach to verification and deployment of adaptive systems that has not been used before. This paper gives an overview of this approach.

Pullum, Laura L [ORNL; Cui, Xiaohui [New York Institute of Technology (NYIT); Vassev, Emil [Lero – The Irish Software Engineering Research Centre; Hinchey, Mike [Lero – The Irish Software Engineering Research Centre; Rouff, Christopher [Lockheed Martin Corporation; Buskens, Richard [Lockheed Martin Corporation

2012-01-01T23:59:59.000Z

435

Influence of Alloy and Solidification Parameters on Grain Refinement in Aluminum Weld Metal due to Inoculation  

Science Conference Proceedings (OSTI)

The goals are: (1) Establish how much Ti/B grain refiner is need to completely refine aluminum weld metal for different alloys and different welding conditions; (2) Characterize how alloy composition and solidification parameters affect weld metal grain refinement; and (3) Apply relevant theory to understand observed behavior. Conclusions are: (1) additions of Ti/B grain refiner to weld metal in Alloys 1050, 5083, and 6082 resulted in significant grain refinement; (2) grain refinement was more effective in GTAW than LBW, resulting in finer grains at lower Ti content - reason is limited time available for equiaxed grain growth in LBW (inability to occlude columnar grain growth); (3) welding travel speed did not markedly affect grain size within GTAW and LBW clusters; and (4) application of Hunt CET analysis showed experimental G to be on the order of the critical G{sub CET}; G{sub CET} was consistently higher for GTAW than for LBW.

Schempp, Philipp [BAM, Germany; Tang, Z. [BIAS, Germany; Cross, Carl E. [Los Alamos National Laboratory; Seefeld, T. [BIAS, Germany; Pittner, A. [BAM, Germany; Rethmeier, M. [BAM, Germany

2012-06-28T23:59:59.000Z

436

Environmental Regulations and Changes in Petroleum Refining Operations  

Gasoline and Diesel Fuel Update (EIA)

Environmental Regulations and Environmental Regulations and Changes in Petroleum Refining Operations By Tancred C.M. Lidderdale Contents * Introduction * Motor Gasoline Summer Volatility (RVP) Regulations o Table 1. Summer Volatility Regulations for Motor Gasoline o Table 2. Refinery Inputs and Production of Normal Butane o Figure 1. Refinery Inputs and Production of Normal Butane o Table 3. Price Relationship Between Normal Butane and Motor Gasoline o Table 4. Market Price Premium for Low Vapor Pressure (RVP) Gasoline * Oxygenate Content of Motor Gasoline o Figure 2. Oxygenate Content of Motor Gasoline o Table 5. Oxygenated and Conventional Motor Gasoline Price Relationship o Table 6. Reformulated and Conventional Motor Gasoline Price Relationship o Figure 3. Price Differences Between RFG or MTBE and Conventional Gasoline

437

The uses of the refined matrix model recursion  

Science Conference Proceedings (OSTI)

We study matrix models in the {beta}-ensemble by building on the refined recursion relation proposed by Chekhov and Eynard. We present explicit results for the first {beta}-deformed corrections in the one-cut and the two-cut cases, as well as two applications to supersymmetric gauge theories: the calculation of superpotentials in N=1 gauge theories, and the calculation of vevs of surface operators in superconformal N=2 theories and their Liouville duals. Finally, we study the {beta}-deformation of the Chern-Simons matrix model. Our results indicate that this model does not provide an appropriate description of the {Omega}-deformed topological string on the resolved conifold, and therefore that the {beta}-deformation might provide a different generalization of topological string theory in toric Calabi-Yau backgrounds.

Brini, Andrea; Marino, Marcos; Stevan, Sebastien [Departement de Physique Theorique et Section de Mathematiques, Universite de Geneve, Geneve CH-1211 (Switzerland)

2011-05-15T23:59:59.000Z

438

Abelianization of BPS Quivers and the Refined Higgs Index  

E-Print Network (OSTI)

We count Higgs "phase" BPS states of general non-Abelian quiver, possibly with loops, by mapping the problem to its Abelian, or toric, counterpart and imposing Weyl invariance later. Precise Higgs index computation is particularly important for quivers with superpotentials; the Coulomb "phase" index is recently shown to miss important BPS states, dubbed intrinsic Higgs states or quiver invariants. We demonstrate how the refined Higgs index is naturally decomposed to a sum over partitions of the charge. We conjecture, and show in simple cases, that this decomposition expresses the Higgs index as a sum over a set of partition-induced Abelian quivers of the same total charge but generically of smaller rank. Unlike the previous approach inspired by a similar decomposition of the Coulomb index, our formulae compute the quiver invariants directly, and thus offer a self-complete routine for counting BPS states.

Seung-Joo Lee; Zhao-Long Wang; Piljin Yi

2013-10-04T23:59:59.000Z

439

Fuel and oxygen addition for metal smelting or refining process  

DOE Patents (OSTI)

A furnace for smelting iron ore and/or refining molten iron is equipped with an overhead pneumatic lance, through which a center stream of particulate coal is ejected at high velocity into a slag layer. An annular stream of nitrogen or argon enshrouds the coal stream. Oxygen is simultaneously ejected in an annular stream encircling the inert gas stream. The interposition of the inert gas stream between the coal and oxygen streams prevents the volatile matter in the coal from combusting before it reaches the slag layer. Heat of combustion is thus more efficiently delivered to the slag, where it is needed to sustain the desired reactions occurring there. A second stream of lower velocity oxygen can be delivered through an outermost annulus to react with carbon monoxide gas rising from slag layer, thereby adding still more heat to the furnace. 7 figs.

Schlichting, M.R.

1994-11-22T23:59:59.000Z

440

DogoIDS: a mobile and active intrusion detection system for IEEE 802.11s wireless mesh networks  

Science Conference Proceedings (OSTI)

Wireless Mesh Networks (WMN) are particularly vulnerable to attacks, since they feature constraint nodes, multi-hop communication, and an open wireless communication channel. These features limit the feasibility of the deployment of contemporary Intrusion ... Keywords: intrusion detection, security, wireless mesh networks

Rodrigo do Carmo; Matthias Hollick

2013-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "adaptive mesh refinement" from the National Library of EnergyBeta (NLEBeta).
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441

On the design of high-performance algorithms for aligning multiple protein sequences on mesh-based multiprocessor architectures  

Science Conference Proceedings (OSTI)

In this paper, we address the problem of multiple sequence alignment (MSA) for handling very large number of proteins sequences on mesh-based multiprocessor architectures. As the problem has been conclusively shown to be computationally complex, we employ ... Keywords: Divisible loads, Mesh topology, Multiple sequence alignment, Protein sequences, Smith--Waterman algorithm

Diana H. P. Low; Bharadwaj Veeravalli; David A. Bader

2007-09-01T23:59:59.000Z

442

On a joint temporal-spatial multi-channel assignment and routing scheme in resource-constrained wireless mesh networks  

Science Conference Proceedings (OSTI)

Use of multiple orthogonal channels can significantly improve network throughput of multi-hop wireless mesh networks (WMNs). In these WMNs where multiple channels are available, channel assignment is done either in a centralized manner, which unfortunately ... Keywords: Channel assignment, Linear programming (LP), Routing, Spatial, Temporal, Throughput, Wireless mesh networks (WMNs)

Yan Jin; Weiping Wang; Yingtao Jiang; Mei Yang

2012-05-01T23:59:59.000Z

443

On the performances of IEEE 802.16(d) mesh CDS-mode networks using Single-Switched-Beam Antennas  

Science Conference Proceedings (OSTI)

The IEEE 802.16(d) mesh coordinated distributed scheduling (CDS) mode is a novel technology for future fixed wireless backbone networks and designed for the use of omnidirectional antennas. The use of Single-Switched-Beam Antennas (SSBAs) may have great ... Keywords: Coordinated distributed scheduling mode, Directional antenna, IEEE 802.16, Mesh network, Switched-beam antenna

Chih-Che Lin; Shie-Yuan Wang; Teng-Wei Hsu

2012-03-01T23:59:59.000Z

444

A cross-layer framework for video-on-demand service in multi-hop WiMax mesh networks  

Science Conference Proceedings (OSTI)

In this work, we introduce a cross-layer framework to favor the video-on-demand service in multi-hop WiMax mesh networks. We first propose a joint solution of admission control and channel scheduling for video streams. The proposed approach guarantees ... Keywords: Cross-layer design, Simulation, Video-on-demand, WiMax, Wireless mesh network

Fei Xie; Kien A. Hua; Ning Jiang

2008-05-01T23:59:59.000Z

445

WiMsh: a simple and efficient tool for simulating IEEE 802.16 wireless mesh networks in ns-2  

Science Conference Proceedings (OSTI)

Wireless mesh networks (WMNs) are two-tier wireless multihop networks. The top tier is made of wireless routers, which provide access to the wireless clients in the bottom tier. One technology for enabling multi-hop communication in the top tier is IEEE ... Keywords: IEEE 802.16, network simulator 2, simulation, wireless mesh networks

Claudio Cicconetti; Ian F. Akyildiz; Luciano Lenzini

2009-03-01T23:59:59.000Z

446

Adaptive sequential controller  

Science Conference Proceedings (OSTI)

An adaptive sequential controller for controlling a circuit breaker or other switching device to substantially eliminate transients on a distribution line caused by closing and opening the circuit breaker. The device adaptively compensates for changes in the response time of the circuit breaker due to aging and environmental effects. A potential transformer provides a reference signal corresponding to the zero crossing of the voltage waveform, and a phase shift comparator circuit compares the reference signal to the time at which any transient was produced when the circuit breaker closed, producing a signal indicative of the adaptive adjustment that should be made. Similarly, in controlling the opening of the circuit breaker, a current transformer provides a reference signal that is compared against the time at which any transient is detected when the circuit breaker last opened. An adaptive adjustment circuit produces a compensation time that is appropriately modified to account for changes in the circuit breaker response, including the effect of ambient conditions and aging. When next opened or closed, the circuit breaker is activated at an appropriately compensated time, so that it closes when the voltage crosses zero and opens when the current crosses zero, minimizing any transients on the distribution line. Phase angle can be used to control the opening of the circuit breaker relative to the reference signal provided by the potential transformer. 15 figs.

El-Sharkawi, M.A.; Xing, J.; Butler, N.G.; Rodriguez, A.

1994-11-01T23:59:59.000Z

447

Plants “remember” drought, adapt  

Science Conference Proceedings (OSTI)

Research carried out at the University of Nebraska-Lincoln (UNL; USA) shows that plants subjected to a previous period of drought learn to deal with the stress owing to their “memories” of the experience. Plants “remember” drought, adapt Inform Magazine

448

Adaptive sequential controller  

DOE Patents (OSTI)

An adaptive sequential controller (50/50') for controlling a circuit breaker (52) or other switching device to substantially eliminate transients on a distribution line caused by closing and opening the circuit breaker. The device adaptively compensates for changes in the response time of the circuit breaker due to aging and environmental effects. A potential transformer (70) provides a reference signal corresponding to the zero crossing of the voltage waveform, and a phase shift comparator circuit (96) compares the reference signal to the time at which any transient was produced when the circuit breaker closed, producing a signal indicative of the adaptive adjustment that should be made. Similarly, in controlling the opening of the circuit breaker, a current transformer (88) provides a reference signal that is compared against the time at which any transient is detected when the circuit breaker last opened. An adaptive adjustment circuit (102) produces a compensation time that is appropriately modified to account for changes in the circuit breaker response, including the effect of ambient conditions and aging. When next opened or closed, the circuit breaker is activated at an appropriately compensated time, so that it closes when the voltage crosses zero and opens when the current crosses zero, minimizing any transients on the distribution line. Phase angle can be used to control the opening of the circuit breaker relative to the reference signal provided by the potential transformer.

El-Sharkawi, Mohamed A. (Renton, WA); Xing, Jian (Seattle, WA); Butler, Nicholas G. (Newberg, OR); Rodriguez, Alonso (Pasadena, CA)

1994-01-01T23:59:59.000Z

449

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

SciTech Connect

This project had goals of advancing the performance capabilities of the numerical general circulation model EULAG and using it to produce a fully operational atmospheric global climate model (AGCM) that can employ either static or dynamic grid stretching for targeted phenomena. The resulting AGCM combined EULAG's advanced dynamics core with the 'physics' of the NCAR Community Atmospheric Model (CAM). Effort discussed below shows how we improved model performance and tested both EULAG and the coupled CAM-EULAG in several ways to demonstrate the grid stretching and ability to simulate very well a wide range of scales, that is, multi-scale capability. We leveraged our effort through interaction with an international EULAG community that has collectively developed new features and applications of EULAG, which we exploited for our own work summarized here. Overall, the work contributed to over 40 peer-reviewed publications and over 70 conference/workshop/seminar presentations, many of them invited.

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

2012-04-09T23:59:59.000Z

450

Table 6. U.S. Refiner Motor Gasoline Prices by Grade and Sales ...  

U.S. Energy Information Administration (EIA)

17 U.S. Energy Information Administration/Petroleum Marketing Monthly February 2012 Table 6. U.S. Refiner Motor Gasoline Prices by Grade and Sales Type

451

Table 3a. Imported Refiner Acquisition Cost of Crude Oil, Projected...  

U.S. Energy Information Administration (EIA) Indexed Site

a. Imported Refiner Acquisition Cost of Crude Oil, Projected vs. Actual" "Projected Price in Constant Dollars" " (constant dollars per barrel in ""dollar year"" specific to each...

452

Real-time Imaging of the Grain Refinement Process of Aluminum ...  

Science Conference Proceedings (OSTI)

K2: Microstructural Development of Plutonium Alloys via Cooling Curve Analysis · K3: Preparation of High Purity Tellurium by Zone Refining Process.

453

Table 47. Refiner Residual Fuel Oil and No. 4 Fuel Volumes by...  

Gasoline and Diesel Fuel Update (EIA)

Information Administration Petroleum Marketing Annual 1996 Table 47. Refiner Residual Fuel Oil and No. 4 Fuel Volumes by PAD District (Thousand Gallons per Day) - Continued...

454

Table 47. Refiner Residual Fuel Oil and No. 4 Fuel Volumes by...  

Gasoline and Diesel Fuel Update (EIA)

Information AdministrationPetroleum Marketing Annual 1999 Table 47. Refiner Residual Fuel Oil and No. 4 Fuel Volumes by PAD District (Thousand Gallons per Day) - Continued...

455

Energy efficiency in the South Africa crude oil refining industry drivers, barriers and opportunities.  

E-Print Network (OSTI)

??Includes abstract. This study has explored a range of barriers, drivers and opportunities to improving energy performance in the South African crude oil refining industry,… (more)

Bergh, Caitlin.

2012-01-01T23:59:59.000Z

456

Regional differences for cost of crude oil to refiners widened in ...  

U.S. Energy Information Administration (EIA)

Glossary For Teachers. Energy Explained. ... Source: U.S. Energy Information Administration, Petroleum Marketing Monthly, Refiner Acquisition Cost of Crude Oil.

457

Table 6. U.S. Refiner Motor Gasoline Prices by Grade and ...  

U.S. Energy Information Administration (EIA)

17 U.S. Energy Information Administration/Petroleum Marketing Monthly December 2013 Table 6. U.S. Refiner Motor Gasoline Prices by Grade and Sales ...

458

Table A2. Refiner/Reseller Prices of Aviation Fuels, Propane...  

Annual Energy Outlook 2012 (EIA)

Marketing Annual 1995 467 Table A2. RefinerReseller Prices of Aviation Fuels, Propane, and Kerosene, by PAD District, 1983-Present (Cents per Gallon Excluding Taxes) -...

459

Table A2. Refiner/Reseller Prices of Aviation Fuels, Propane...  

Gasoline and Diesel Fuel Update (EIA)

Marketing Annual 1999 421 Table A2. RefinerReseller Prices of Aviation Fuels, Propane, and Kerosene, by PAD District, 1983-Present (Cents per Gallon Excluding Taxes) -...

460

Adaptation and adaptability : expectant design for resilience in coastal urbanity  

E-Print Network (OSTI)

What is the nature of and possibility for urban resiliency through adaptation? Adaptation implies responsiveness to phenomena that are disruptive to a system's functioning; it is a willful evolution in response to changed ...

Ruskeepää, Laura A. Delaney (Laura Ashley Delaney)

2011-01-01T23:59:59.000Z

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


461

Parallel adaptive Cartesian upwind methods for shock-driven multiphysics simulation  

SciTech Connect

The multiphysics fluid-structure interaction simulation of shock-loaded thin-walled structures requires the dynamic coupling of a shock-capturing flow solver to a solid mechanics solver for large deformations. By combining a Cartesian embedded boundary approach with dynamic mesh adaptation a generic software framework for such flow solvers has been constructed that allows easy exchange of the specific hydrodynamic finite volume upwind scheme and coupling to various explicit finite element solid dynamics solvers. The paper gives an overview of the computational approach and presents first simulations that couple the software to the general purpose solid dynamics code DYNA3D.

Deiterding, Ralf [ORNL

2011-01-01T23:59:59.000Z

462

Extending a CAD-Based Cartesian Mesh Generator for the Lattice Boltzmann Method  

SciTech Connect

This paper describes the development of a custom preprocessor for the PaRAllel Thermal Hydraulics simulations using Advanced Mesoscopic methods (PRATHAM) code based on an open-source mesh generator, CartGen [1]. PRATHAM is a three-dimensional (3D) lattice Boltzmann method (LBM) based parallel flow simulation software currently under development at the Oak Ridge National Laboratory. The LBM algorithm in PRATHAM requires a uniform, coordinate system-aligned, non-body-fitted structured mesh for its computational domain. CartGen [1], which is a GNU-licensed open source code, already comes with some of the above needed functionalities. However, it needs to be further extended to fully support the LBM specific preprocessing requirements. Therefore, CartGen is being modified to (i) be compiler independent while converting a neutral-format STL (Stereolithography) CAD geometry to a uniform structured Cartesian mesh, (ii) provide a mechanism for PRATHAM to import the mesh and identify the fluid/solid domains, and (iii) provide a mechanism to visually identify and tag the domain boundaries on which to apply different boundary conditions.

Cantrell, J Nathan [ORNL; Inclan, Eric J [ORNL; Joshi, Abhijit S [ORNL; Popov, Emilian L [ORNL; Jain, Prashant K [ORNL

2012-01-01T23:59:59.000Z

463

Using Variable Resolution Meshes to Model Tropical Cyclones in the Community Atmosphere Model  

Science Conference Proceedings (OSTI)

A statically-nested, variable-mesh option has recently been introduced into the Community Atmosphere Model’s (CAM) Spectral Element (SE) dynamical core that has become the default in CAM version 5.3. This paper presents a series of tests of ...

Colin M. Zarzycki; Christiane Jablonowski; Mark A. Taylor

464

Survey paper: A survey on routing algorithms for wireless Ad-Hoc and mesh networks  

Science Conference Proceedings (OSTI)

Wireless networking technology is evolving as an inexpensive alternative for building federated and community networks (relative to the traditional wired networking approach). Besides its cost-effectiveness, a wireless network brings operational efficiencies, ... Keywords: Ad-Hoc network, Multi-hop network, Routing algorithm, Wireless Mesh Network (WMN)

Eiman Alotaibi; Biswanath Mukherjee

2012-02-01T23:59:59.000Z

465

Lagrangian shock hydrodynamics on tetrahedral meshes: A stable and accurate variational multiscale approach  

Science Conference Proceedings (OSTI)

In the past, a number of attempts have failed to robustly compute highly transient shock hydrodynamics flows on tetrahedral meshes. To a certain degree, this is not a surprise, as prior attempts emphasized enhancing the structure of shock-capturing operators ... Keywords: Lagrangian shock hydrodynamics, Nodal finite element method, Stabilized methods, Tetrahedral grids, Updated Lagrangian formulation, Variational multiscale analysis

G. Scovazzi

2012-10-01T23:59:59.000Z

466

QuRiNet: A Wide-Area Wireless Mesh Testbed for Research and Experimental Evaluations  

E-Print Network (OSTI)

in QuRiNet are powered by solar panels, running with multiple radios. QuRiNet provides the backbone in Figure 1. All nodes, except the gateway nodes, use solar power due to the lack of connectivity as a commu- nity rooftop wireless mesh network [2]. This network has to compete with home wireless networks

California at Davis, University of

467

Mimetic finite difference method for the Stokes problem on polygonal meshes  

Science Conference Proceedings (OSTI)

Various approaches to extend finite element methods to non-traditional elements (general polygons, pyramids, polyhedra, etc.) have been developed over the last decade. The construction of basis functions for such elements is a challenging task and may ... Keywords: Incompressible Stokes equations, Mimetic discretization, Polygonal mesh

L. Beirão da Veiga; V. Gyrya; K. Lipnikov; G. Manzini

2009-10-01T23:59:59.000Z

468

Hybrid rendering of dynamic heightfields using ray-casting and mesh rasterization  

Science Conference Proceedings (OSTI)

This paper presents a flexible hybrid method designed to render heightfield data, such as terrains, on GPU. It combines two traditional techniques, namely mesh-based rendering and per-pixel ray-casting. A heuristic is proposed to dynamically choose between ...

Lucas Ammann; Olivier Génevaux; Jean-Michel Dischler

2010-05-01T23:59:59.000Z

469

Improvement security for RuBee radio-WiMAX mesh networks  

Science Conference Proceedings (OSTI)

Next generation communication standard integrate various access networks technology to become mesh networks. One of air interface standard is metropolitan area wireless broadband service. IEEE 802.16 is the basis for Worldwide Interoperability for Microwave ... Keywords: AAA, RuBee (IEEE 1902.1), WiMAX, gateway access point, group identity key

Tin-Yu Wu; Jhong-Ci Wu; Wei-Fang Weng

2008-09-01T23:59:59.000Z

470

Evaluation of Rugged Wireless Mesh Nodes for Use In Emergency Response  

SciTech Connect

During the summer of 2007, engineers at the Idaho National Laboratory (INL) conducted a two-day evaluation of commercially available battery powered, wireless, self-forming mesh nodes for use in emergency response. In this paper, the author describes the fundamentals of this emerging technology, applciations for emergency response and specific results of the technology evaluation conducted at the Idaho National Laboratory.

Kevin L Young; Alan M Snyder

2007-11-01T23:59:59.000Z

471

IEEE/ACM TRANSACTIONS ON NETWORKING 1 Optimizing 802.11 Wireless Mesh Networks Based  

E-Print Network (OSTI)

IEEE/ACM TRANSACTIONS ON NETWORKING 1 Optimizing 802.11 Wireless Mesh Networks Based on Physical channel state, for example, by com- paring the measured on-air received energy in a channel against Manuscript received August 15, 2007; revised April 11, 2008 and April 11, 2008; approved by IEEE/ACM

Roy, Sumit

472

Assuring QoS in wireless mesh networks with misbehaving users  

Science Conference Proceedings (OSTI)

This paper deals with the problem of QoS provisioning in wireless mesh networks in the presence of misbehaving users. To mitigate the impact of such users, a misbehavior-aware QoS architecture is proposed. The results of simulation studies show the most ...

Szymon Szott

2009-04-01T23:59:59.000Z

473

Development of a Mesh Generation Code with a Graphical Front-End: A Case Study  

Science Conference Proceedings (OSTI)

Scientists and engineers are increasingly developing software to enable them to do their work. A number of characteristics differentiate the software development environment in which a scientist or engineer works from the development environment in which ... Keywords: Computational Engineering, Lessons Learned, Mesh-generation Code, Software Development, Software Engineering

Jeffrey Carver

2011-10-01T23:59:59.000Z

474

An efficient centralized scheduling algorithm for IEEE 802.16 multi-radio mesh networks  

Science Conference Proceedings (OSTI)

In centralized scheduling for IEEE 802.16 mesh networks, all packets should be transported through the BS (Base Station). The links to or from the BS become the system's bottleneck and the throughput is heavily impacted by the interference. To solve ... Keywords: WiMax, multi-radios, routing, scheduling

Jun Wang; Weijia Jia; Liusheng Huang

2008-01-01T23:59:59.000Z

475

Performance evaluation of scheduling in IEEE 802.16 based wireless mesh networks  

Science Conference Proceedings (OSTI)

IEEE 802.16 employs TDMA (Time Division Multiple Access) as the access method and the policy for selecting scheduled links in a given time slot will definitely impact the system performance. We propose a collision-free centralized scheduling algorithm ... Keywords: IEEE 802.16, Link scheduling, Relay model, Wireless access networks, Wireless mesh networks

Bo Han; Weijia Jia; Lidong Lin

2007-02-01T23:59:59.000Z

476

Adaptive Constraints for Feature Tracking  

Science Conference Proceedings (OSTI)

In this paper extensions to an existing tracking algorithm are described. These extensions implement adaptive tracking constraints in the form of regional upper-bound displacements and an adaptive track smoothness constraint. Together, these ...

K. I. Hodges

1999-06-01T23:59:59.000Z

477

Comparative Omics-Driven Genome Annotation Refinement: Application across Yersiniae  

SciTech Connect

Genome sequencing continues to be a rapidly evolving technology, yet most downstream aspects of genome annotation pipelines remain relatively stable or are even being abandoned. To date, the perceived value of manual curation for genome annotations is not offset by the real cost and time associated with the process. In order to balance the large number of sequences generated, the annotation process is now performed almost exclusively in an automated fashion for most genome sequencing projects. One possible way to reduce errors inherent to automated computational annotations is to apply data from 'omics' measurements (i.e. transcriptional and proteomic) to the un-annotated genome with a proteogenomic-based approach. This approach does require additional experimental and bioinformatics methods to include omics technologies; however, the approach is readily automatable and can benefit from rapid developments occurring in those research domains as well. The annotation process can be improved by experimental validation of transcription and translation and aid in the discovery of annotation errors. Here the concept of annotation refinement has been extended to include a comparative assessment of genomes across closely related species, as is becoming common in sequencing efforts. Transcriptomic and proteomic data derived from three highly similar pathogenic Yersiniae (Y. pestis CO92, Y. pestis pestoides F, and Y. pseudotuberculosis PB1/+) was used to demonstrate a comprehensive comparative omic-based annotation methodology. Peptide and oligo measurements experimentally validated the expression of nearly 40% of each strain's predicted proteome and revealed the identification of 28 novel and 68 previously incorrect protein-coding sequences (e.g., observed frameshifts, extended start sites, and translated pseudogenes) within the three current Yersinia genome annotations. Gene loss is presumed to play a major role in Y. pestis acquiring its niche as a virulent pathogen, thus the discovery of many translated pseudogenes underscores a need for functional analyses to investigate hypotheses related to divergence. Refinements included the discovery of a seemingly essential ribosomal protein, several virulence-associated factors, and a transcriptional regulator, among other proteins, most of which are annotated as hypothetical, that were missed during annotation.

Rutledge, Alexandra C.; Jones, Marcus B.; Chauhan, Sadhana; Purvine, Samuel O.; Sanford, James; Monroe, Matthew E.; Brewer, Heather M.; Payne, Samuel H.; Ansong, Charles; Frank, Bryan C.; Smith, Richard D.; Peterson, Scott; Motin, Vladimir L.; Adkins, Joshua N.

2012-03-27T23:59:59.000Z

478

FDR3 --A Modern Refinement Checker for CSP Thomas Gibson-Robinson, Philip Armstrong,  

E-Print Network (OSTI)

FDR3 -- A Modern Refinement Checker for CSP Thomas Gibson-Robinson, Philip Armstrong, Alexandre.roscoe}@cs.ox.ac.uk Abstract. FDR3 is a complete rewrite of the CSP refinement checker FDR2, incorporating a significant number describe the new algorithm that FDR3 uses to construct its in- ternal representation of CSP processes

Oxford, University of

479

To appear in EPTCS. A CSP account of Event-B refinement  

E-Print Network (OSTI)

To appear in EPTCS. A CSP account of Event-B refinement Steve Schneider Department of Computing a CSP account of Event-B refinement, with a treatment for the first time of splitting events and of anticipated events. To this end, we define a CSP seman- tics for Event-B and show how the different forms

Doran, Simon J.

480

A refinement-based compositional reasoning framework for pipelined machine verification  

Science Conference Proceedings (OSTI)

We present a refinement-based compositional framework for showing that pipelined machines satisfy the same safety and liveness properties as their non-pipelined specifications. Our framework consists of a set of convenient, easily applicable, and complete ... Keywords: compositional reasoning, pipelined machine verification, refinement

Panagiotis Manolios; Sudarshan K. Srinivasan

2008-04-01T23:59:59.000Z

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


481

Aspects of Western Refining, Inc.'s Proposed Acquisition of Giant Industries, Inc.  

Reports and Publications (EIA)

Presentation of company-level, non-proprietary data and relevant aggregate data for U.S. refinery capacity and gasoline marketing of Western Refining and Giant Industries to inform discussions of Western Refining Inc.'s proposed acquisition of Giant Industries Inc. for a total of $1.5 billion, which was announced August 28, 2006.

Neal Davis

2006-09-12T23:59:59.000Z

482

Public, agencies key players in L. A. refiner's program  

Science Conference Proceedings (OSTI)

In the middle of the world's largest gasoline market, and what is considered the most hostile environment toward refiners, Mobil Oil Corp. runs a lean, efficient, 130,000 b/d refinery. The refinery processes 13--14[degree] API San Joaquin crude oil, converting roughly 85% to gasoline, jet fuel, and diesel fuel. It also makes low-sulfur coke. Located in the Los angeles suburb of Torrance, California, the refinery is literally across the street from residential neighborhoods of medium to high-priced houses. In addition to meeting strict local, state, and federal regulations, the refinery has to make sure its neighbors are satisfied with its operations. To meet this need, the refinery operates a 24-hr hotline that community residents can call to ask questions and voice concerns. The paper discusses agency interaction, department structure, air pollutants, air permits, reporting requirements, the clean air incentives program, NO[sub x] sources, SO[sub x] sources, particulates, fugitive emissions, CO, HF, waste water, groundwater, storm water, soil treatments, and reformulation rules for diesel fuels.

Rhodes, A.K.

1994-05-30T23:59:59.000Z

483

Refinement and Formalization of SemiFormal Use Case Descriptions  

E-Print Network (OSTI)

Behavioral models of computer systems are required for their synthesis, for verification and validation. The system behavior is usually described in requirements specifications. However, most specifications are provided in natural language or in a semi-formal way. Incompleteness and ambiguity inhibit their successful exploitation by tools. In this paper an approach for stepwise refinement and formalization of natural-language or semiformal descriptions is presented. Based on the structure of Use Case descriptions, the formalization of behavioral information is reached by a stepwise transformation of an input text to structured sentences with a well-defined syntax by performing linguistic analyses. The terms of the text are replaced by references to other items, i.e. of the glossary. By providing a tool-supported text output with hypertext-like navigation facilities, a verification of the result by the human experts is provided. The resulting behavioral description is suitable for a derivation of dynamic models, e.g. message-sequence charts and state diagrams.

Matthias Riebisch; Michael Hübner

2004-01-01T23:59:59.000Z

484

Lomov_EulHyd_VE.ppt  

National Nuclear Security Administration (NNSA)

Patch-Based Adaptive Mesh Refinement Patch-Based Adaptive Mesh Refinement for Hydrodynamics Joint Russian-American Five-Laboratory Conference on Computational Mathematics/Physics Vienna, Austria June 19-23 2005 Richard Pember, Jeffrey Greenough AX Division Ben Liu, Ilya Lomov Earth Science Division 5LC 2005 rbp. 2 Overview * "AMR 101" for gas dynamics * Overview of a single material algorithm on a structured Eulerian grid * Issues for multimaterial cells * Assorted results 5LC 2005 rbp. 3 Berger-Oliger-Colella style adaptive mesh refinement * Features of Berger-Oliger-Colella approach - Patch consists of high "error" zones grouped along with some (but not many) low-error zones - Locally refine patches of the domain in space and time - Each patch is a topologically rectangular structured grid

485

Adaptive Detached Eddy Simulation of a High-Lift Wing with Active Flow  

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

Full span view of the flow past a vertical tail assembly of a commercial aircraft with active flow control at Re=360,000. Full span view of the flow past a vertical tail assembly of a commercial aircraft with active flow control at Re=360,000. Full span view of the flow past a vertical tail assembly of a commercial aircraft with active flow control at Re=360,000. This picture highlights the root and tip vortex along with the turbulent structures in the wake of a deflected rudder through isosurface of instantaneous Q criterion colored by speed on a locally adapted unstructured finite element mesh with 1.2 billion elements. Michel Rasquin, Argonne National Laboratory Adaptive Detached Eddy Simulation of a High-Lift Wing with Active Flow Control PI Name: Kenneth Jansen PI Email: jansenke@colorado.edu Institution: University of Colorado Allocation Program: INCITE Allocation Hours at ALCF:

486

Photodegradation of mutagens in solvent-refined coal liquids  

SciTech Connect

The purpose of this investigation was to evaluate any changes in the chemical composition and microbial mutagenicities of two representative solvent-refined coal (SRC) liquids as a function of exposure time to sunlight and air. This information was desired to assess potential health hazards arising from ground spills of these liquids during production, transport and use. Results of microbial mutagenicity assays using Salmonella typhimurium TA98, conducted after exposure, showed that the mutagenicities of both an SRC-II fuel oil blend and an SRC-I process solvent decreased continuously with exposure time to air and that the decrease was accelerated by simultaneous exposure to simulated sunlight. The liquids were exposed as thin layers supported on surfaces of glass, paper, clay or aluminum; but the type of support had little effect on the results. The contrast between these results and the reported increases of mutagenesis in organisms exposed simultaneously to coal liquids and near-ultraviolet light suggested that short-lived mutagenic intermediates, e.g., organic free radicals, were formed in the liquids during exposure to light. The highest activities of microbial mutagenicity in the SRC liquids were found in fractions rich in amino polycyclic aromatic hydrocarbons (amino PAH). After a 36-hour exposure of the fuel oil blend to air in the dark, the mutagenicity of its amine-rich fraction was reduced by 65%; whereas a 36-hour exposure in the light reduced the mutagenicity of this fraction by 92%. Similar rates of reduction in mutagenicity were achieved in exposures of the process solvent. The mutagenicities of other chemical fractions remained low during exposure.

Kalkwarf, D.R.; Stewart, D.L.; Pelroy, R.A.; Weimer, W.C.

1984-04-01T23:59:59.000Z

487

Routing and packet scheduling for throughput maximization in ieee 802.16 mesh networks  

E-Print Network (OSTI)

Abstract — This paper considers the problem of maximizing the system throughput in IEEE 802.16 broadband access networks with mesh topology, and the following results are presented. We first consider a simplified linear network with only uplink traffic and provide an optimal scheduling algorithm and establish an analytical result on the length of the schedule. We then consider the problem of routing and packet scheduling in general topology, and show its NPcompleteness. We also provide an ILP formulation for this problem. Based on our optimal algorithm for linear networks, we propose algorithms that find routes and schedules of packet transmissions in general mesh topologies. The performance of our proposed algorithms is analyzed using the NS-2 simulator. The results show that the suggested algorithms perform significantly better than other existing algorithms.

Fanchun Jin; Amrinder Arora; Jinho Hwang; Hyeong-ah Choi

2007-01-01T23:59:59.000Z

488

Performance evaluation of scheduling in IEEE 802.16 based wireless mesh networks  

E-Print Network (OSTI)

Abstract-We propose an efficient centralized scheduling algorithm in IEEE 802.16 based Wireless Mesh Networks (WMN) to provide high qualified wireless multimedia services. Our algorithm takes special attention on the relay function of the mesh nodes in a transmission tree which is seldom studied in previous research. Some important design metrics, such as fairness, channel utilization and transmission delay are considered in this scheduling algorithm. IEEE 802.16 employs TDMA and the selection policy for scheduled links in a time slot will definitely impact the system performance. We evaluated the proposed algorithm with four selection criteria through extensive simulations and the results are instrumental for improving the performance of IEEE 802.16 based WMNs in terms of link scheduling. I.

Bo Han; Fung Po Tso; Lidong Lin; Weijia Jia

2007-01-01T23:59:59.000Z

489

A Parallel Unstructured-Mesh Methodology for Device-Scale Combustion Calculations  

DOE Green Energy (OSTI)

At Los Alamos we are developing a parallel, unstructured-mesh, finite-volume CFD methodology for the simulation of chemically reactive flows in complex geometries. The methodology is embodied in the CHAD (Computational Hydrodynamics for Advanced Design) code. In this report we give an overview of the CHAD numerical methodology and present parallel scaling results for calculations of flows in a four-valve diesel engine.

O'Rourke, P.J.; Sahota, M.S.; Zhang, S.

1998-12-03T23:59:59.000Z

490

Mesh generation and energy group condensation studies for the jaguar deterministic transport code  

Science Conference Proceedings (OSTI)

The deterministic transport code Jaguar is introduced, and the modeling process for Jaguar is demonstrated using a two-dimensional assembly model of the Hoogenboom-Martin Performance Benchmark Problem. This single assembly model is being used to test and analyze optimal modeling methodologies and techniques for Jaguar. This paper focuses on spatial mesh generation and energy condensation techniques. In this summary, the models and processes are defined as well as thermal flux solution comparisons with the Monte Carlo code MC21. (authors)

Kennedy, R. A.; Watson, A. M.; Iwueke, C. I.; Edwards, E. J. [Knolls Atomic Power Laboratory, Bechtel Marine Propulsion Corporation, P.O. Box 1072, Schenectady, NY 12301-1072 (United States)

2012-07-01T23:59:59.000Z

491

Future Change of Western North Pacific Typhoons: Projections by a 20-km-Mesh Global Atmospheric Model  

Science Conference Proceedings (OSTI)

Projected future changes in tropical cyclone (TC) activity over the western North Pacific (WNP) under the Special Report on Emissions Scenarios (SRES) A1B emission scenario were investigated using a 20-km-mesh, very-high-resolution Meteorological ...

Hiroyuki Murakami; Bin Wang; Akio Kitoh

2011-02-01T23:59:59.000Z

492

A Moving-Mesh Finite Element Method and its Application to the Numerical Solution of Phase-Change  

E-Print Network (OSTI)

School of Computing, University of Leeds, UK R. Mahmood Computer Division, Pakistan Institute of Nuclear Science and Technology (PINSTECH), Islamabad, Pakistan A distributed Lagrangian moving-mesh finite element

Jimack, Peter

493

Photocatalytic destruction of atrazine using TiO{sub 2} mesh  

SciTech Connect

The optimization of a technology for the TiO{sub 2}-mediated solar photocatalysis of atrazine is described. The target users of this technology might be agrochemical dealers, manufacturers, and possibly farmers. Studies were performed to determine the ideal cover material for such a reactor based on UV light transmitting properties. The best cover material was a UV transmitting acrylic. The TiO{sub 2} employed for this technology was bound to fiberglass mesh. The effects of mesh amount, stirring, water impurities, concentration of pesticide, and source of UV light (mercury vapor lamp vs. solar) were also determined. The most efficient photocatalysis was achieved using five layers of mesh, a stirred reaction, water low in carbonate and other ions, a dilute waste stream, and solar irradiation rather than a mercury-vapor lamp. The formation and disappearance of eight intermediates were followed in a 2429 h indoor experiment comparing pure and formulated atrazine. A modified reaction mechanism was proposed based on studies of the detected intermediates.

Pugh, K.C.; Kiserow, D.J.; Sullivan, J.M.; Grinstead, J.H. Jr.

1994-10-01T23:59:59.000Z

494

Design and evaluation of a new MAC protocol for long-distance 802.11 mesh networks  

Science Conference Proceedings (OSTI)

802.11 has been used well beyond its original intended use of WLANs. Of particular interest to us in this paper is its use in long-distance mesh networks being designed/used for low-cost rural connectivity. We describe in detail a new MAC protocol, called ... Keywords: 802.11 mesh networks, MAC design, network topology design, signal-to-interference ratio

Bhaskaran Raman; Kameswari Chebrolu

2005-08-01T23:59:59.000Z

495

,"U.S. Aviation Gasoline Refiner Sales Volumes"  

U.S. Energy Information Administration (EIA) Indexed Site

Aviation Gasoline Refiner Sales Volumes" Aviation Gasoline Refiner Sales Volumes" ,"Click worksheet name or tab at bottom for data" ,"Worksheet Name","Description","# Of Series","Frequency","Latest Data for" ,"Data 1","U.S. Aviation Gasoline Refiner Sales Volumes",2,"Monthly","9/2013","1/15/1983" ,"Release Date:","12/2/2013" ,"Next Release Date:","1/2/2014" ,"Excel File Name:","pet_cons_refoth_c_nus_eppv_mgalpd_m.xls" ,"Available from Web Page:","http://www.eia.gov/dnav/pet/pet_cons_refoth_c_nus_eppv_mgalpd_m.htm" ,"Source:","Energy Information Administration" ,"For Help, Contact:","infoctr@eia.gov"

496

,"Aviation Gasoline Sales to End Users Refiner Sales Volumes"  

U.S. Energy Information Administration (EIA) Indexed Site

Aviation Gasoline Sales to End Users Refiner Sales Volumes" Aviation Gasoline Sales to End Users Refiner Sales Volumes" ,"Click worksheet name or tab at bottom for data" ,"Worksheet Name","Description","# Of Series","Frequency","Latest Data for" ,"Data 1","Aviation Gasoline Sales to End Users Refiner Sales Volumes",60,"Monthly","9/2013","1/15/1983" ,"Release Date:","12/2/2013" ,"Next Release Date:","1/2/2014" ,"Excel File Name:","pet_cons_refoth_a_eppv_vtr_mgalpd_m.xls" ,"Available from Web Page:","http://www.eia.gov/dnav/pet/pet_cons_refoth_a_eppv_vtr_mgalpd_m.htm" ,"Source:","Energy Information Administration"

497

,"U.S. Sales to End Users, Total Refiner Motor Gasoline Sales Volumes"  

U.S. Energy Information Administration (EIA) Indexed Site

Users, Total Refiner Motor Gasoline Sales Volumes" Users, Total Refiner Motor Gasoline Sales Volumes" ,"Click worksheet name or tab at bottom for data" ,"Worksheet Name","Description","# Of Series","Frequency","Latest Data for" ,"Data 1","Products for Refiner Gasoline Volumes",1,"Monthly","9/2013","1/15/1983" ,"Data 2","by Grade",3,"Monthly","9/2013","1/15/1983" ,"Data 3","by Formulation",3,"Monthly","9/2013","1/15/1994" ,"Release Date:","12/2/2013" ,"Next Release Date:","1/2/2014" ,"Excel File Name:","pet_cons_refmg_d_nus_vtr_mgalpd_m.xls"

498

Influence of Aluminum Content on Grain Refinement and Strength of AZ31 Magnesium GTA Weld Metal  

SciTech Connect

The goal is to characterize the effect of Al content on AZ31 weld metal, the grain size and strength, and examine role of Al on grain refinement. The approach is to systematically vary the aluminum content of AZ31 weld metal, Measure average grain size in weld metal, and Measure cross-weld tensile properties and hardness. Conclusions are that: (1) increased Al content in AZ31 weld metal results in grain refinement Reason: higher undercooling during solidification; (2) weld metal grain refinement resulted in increased strength & hardness Reason: grain boundary strengthening; and (3) weld metal strength can be raised to wrought base metal levels.

Babu, N. Kishore [Singapore Institute of Manufacturing Technology; Cross, Carl E. [Los Alamos National Laboratory

2012-06-28T23:59:59.000Z

499

,"U.S. Residual Fuel Oil Refiner Sales Volumes"  

U.S. Energy Information Administration (EIA) Indexed Site

Refiner Sales Volumes" Refiner Sales Volumes" ,"Click worksheet name or tab at bottom for data" ,"Worksheet Name","Description","# Of Series","Frequency","Latest Data for" ,"Data 1","U.S. Residual Fuel Oil Refiner Sales Volumes",2,"Monthly","9/2013","1/15/1983" ,"Release Date:","12/2/2013" ,"Next Release Date:","1/2/2014" ,"Excel File Name:","pet_cons_refres_c_nus_eppr_mgalpd_m.xls" ,"Available from Web Page:","http://www.eia.gov/dnav/pet/pet_cons_refres_c_nus_eppr_mgalpd_m.htm" ,"Source:","Energy Information Administration" ,"For Help, Contact:","infoctr@eia.gov"

500

,"U.S. Motor Gasoline Refiner Sales Volumes"  

U.S. Energy Information Administration (EIA) Indexed Site

Refiner Sales Volumes" Refiner Sales Volumes" ,"Click worksheet name or tab at bottom for data" ,"Worksheet Name","Description","# Of Series","Frequency","Latest Data for" ,"Data 1","U.S. Motor Gasoline Refiner Sales Volumes",6,"Monthly","9/2013","1/15/1983" ,"Release Date:","12/2/2013" ,"Next Release Date:","1/2/2014" ,"Excel File Name:","pet_cons_refmg_c_nus_epm0_mgalpd_m.xls" ,"Available from Web Page:","http://www.eia.gov/dnav/pet/pet_cons_refmg_c_nus_epm0_mgalpd_m.htm" ,"Source:","Energy Information Administration" ,"For Help, Contact:","infoctr@eia.gov"