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1

CONVERGENCE OF A MULTISCALE FINITE ELEMENT METHOD ...  

E-Print Network [OSTI]

Mar 3, 1999 ... In this paper, we consider solving a class of two-dimensional, second order, el- liptic boundary ... a standard finite element or finite difference method is used to solve the equations, the degrees of ..... terfaces. The result depends on the geometry of the jump interfaces. ...... a measure of the relative error.

1999-04-17T23:59:59.000Z

2

FINITE ELEMENT METHOD IN FLUID MECHANICS & HEAT TRANSFER  

E-Print Network [OSTI]

FINITE ELEMENT METHOD IN FLUID MECHANICS & HEAT TRANSFER AERSP-560 Department : Aerospace element techniques to especially fluid flow and heat transfer problems. A student who successfully method and write full sized application codes for analyzing fluid flow and heat transfer problems

Camci, Cengiz

3

A NONCONFORMING MIXED FINITE ELEMENT METHOD FOR ...  

E-Print Network [OSTI]

of the time-harmonic Maxwell's equations in a three-dimensional, bounded ... tric conductivity from measurements of natural electric and magnetic fields on the .... Let (?s(?) ¡s) and (?s(?) ¡s) indicate standard, complex Sobolev spaces ..... continuity constraints at the centroids of the interfaces between adjacent elements:.

1910-10-30T23:59:59.000Z

4

Generalized finite element method for multiscale analysis  

E-Print Network [OSTI]

by the Partition of Unity Method (PUM). It is shown that the p-version of the Generalized FEM using mesh-based handbook functions is capable of achieving very high accuracy. It is also analyzed that the effect of the main factors affecting the accuracy...

Zhang, Lin

2004-11-15T23:59:59.000Z

5

AN ADAPTIVE SURFACE FINITE ELEMENT METHOD BASED ON VOLUME MESHES  

E-Print Network [OSTI]

makes use of a (standard) outer volume mesh to discretize an equation on a two-dimensional surface, interface, finite element, level set method, adaptivity, error estimator AMS subject classification. 65N15 measure The first author was partially supported by National Science Foundation grant DMS-1016094

Demlow, Alan

6

A finite element method for low-speed compressible flows.  

SciTech Connect (OSTI)

The derivation and justification for various low-speed approximations to the fully compressible, Navier-Stokes equations are presented. A numerical formulation based on the finite element method is developed and implemented as an extension to the standard Boussinesq equations. Example steady and transient flow problems are simulated to examine the performance of the numerical algorithm and the solution differences with the more commonly studied Boussinesq approximation.

Martinez, Mario J.; Gartling, David K.

2003-04-01T23:59:59.000Z

7

SIMULATION OF RADIO-FREQUENCY ABLATION USING COMPOSITE FINITE ELEMENT METHODS  

E-Print Network [OSTI]

with Composite-Finite- Element (CFE) methods2 . CFE methods are characterized by the capa- bility of resolving

Preusser, Tobias

8

Curved finite elements by the method of initial strains  

E-Print Network [OSTI]

, pp. 383-432. 2. Clough, R. W. , "Comparison of Three Dimensional Finite Elements, " Proceedin s of the S osium on A lication of Finite Element Mhd l. t''i~Et f, Vd6'ltUt ty, 1969, pp. 1-26. 3. Stricklin, J. A. , informal proposal submitted to Dr...

Leick, Roger Dale

1974-01-01T23:59:59.000Z

9

Hypersonic heat transfer and anisotropic visualization with a higher order discontinuous Galerkin finite element method .  

E-Print Network [OSTI]

??Higher order discretizations of the Navier-Stokes equations promise greater accuracy than conventional computational aerodynamics methods. In particular, the discontinuous Galerkin (DG) finite element method has… (more)

Quattrochi, Douglas J. (Douglas John)

2006-01-01T23:59:59.000Z

10

Evaluation of Finite Element Method Based Software for Simulation of Hydropower Generator - Power Grid Interaction.  

E-Print Network [OSTI]

?? The accuracy, ease of use, and execution time of the finite element method based software Maxwell coupled to the system simulation software Simplorer was… (more)

Persarvet, Gustav

2011-01-01T23:59:59.000Z

11

An implementation analysis of the linear discontinuous finite element method  

SciTech Connect (OSTI)

This paper provides an implementation analysis of the linear discontinuous finite element method (LD-FEM) that spans the space of (l, x, y, z). A practical implementation of LD includes 1) selecting a computationally efficient algorithm to solve the 4 x 4 matrix system Ax = b that describes the angular flux in a mesh element, and 2) choosing how to store the data used to construct the matrix A and the vector b to either reduce memory consumption or increase computational speed. To analyze the first of these, three algorithms were selected to solve the 4 x 4 matrix equation: Cramer's rule, a streamlined implementation of Gaussian elimination, and LAPACK's Gaussian elimination subroutine dgesv. The results indicate that Cramer's rule and the streamlined Gaussian elimination algorithm perform nearly equivalently and outperform LAPACK's implementation of Gaussian elimination by a factor of 2. To analyze the second implementation detail, three formulations of the discretized LD-FEM equations were provided for implementation in a transport solver: 1) a low-memory formulation, which relies heavily on 'on-the-fly' calculations and less on the storage of pre-computed data, 2) a high-memory formulation, which pre-computes much of the data used to construct A and b, and 3) a reduced-memory formulation, which lies between the low - and high-memory formulations. These three formulations were assessed in the Jaguar transport solver based on relative memory footprint and computational speed for increasing mesh size and quadrature order. The results indicated that the memory savings of the low-memory formulation were not sufficient to warrant its implementation. The high-memory formulation resulted in a significant speed advantage over the reduced-memory option (10-50%), but also resulted in a proportional increase in memory consumption (5-45%) for increasing quadrature order and mesh count; therefore, the practitioner should weigh the system memory constraints against any required runtime constraints to determine which option is more suitable for his or her specific applications. (authors)

Becker, T. L. [Bechtel Marine Propulsion Corporation, Knolls Atomic Power Laboratory, P.O. Box 1072, Schenectady, NY 12301-1072 (United States)

2013-07-01T23:59:59.000Z

12

LOCKING-FREE FINITE ELEMENT METHOD FOR A BENDING MOMENT FORMULATION OF TIMOSHENKO BEAMS  

E-Print Network [OSTI]

LOCKING-FREE FINITE ELEMENT METHOD FOR A BENDING MOMENT FORMULATION OF TIMOSHENKO BEAMS FELIPE LEPE for Timo- shenko beams. It is known that standard finite elements applied to this model lead to wrong results when the thickness of the beam t is small. Here, we consider a mixed formulation in terms

Rodríguez, Rodolfo

13

Hypersonic heat transfer and anisotropic visualization with a higher order discontinuous Galerkin finite element method  

E-Print Network [OSTI]

Higher order discretizations of the Navier-Stokes equations promise greater accuracy than conventional computational aerodynamics methods. In particular, the discontinuous Galerkin (DG) finite element method has O(hP+l) ...

Quattrochi, Douglas J. (Douglas John)

2006-01-01T23:59:59.000Z

14

Nonlinear structural finite element analysis using the preconditioned Lanczos method on serial and parallel computers  

Science Journals Connector (OSTI)

The application of the Lanczos algorithm in Newton-like methods for solving non-linear systems of equations arising in nonlinear structural finite element analysis is presented. It is shown that with appropria...

Th. Rottner; I. Lenhardt; G. Alefeld; K. Schweizerhof

1997-09-01T23:59:59.000Z

15

Simulation of Fuel Oil System in Marine Engine Simulator Based on Finite Element Method  

Science Journals Connector (OSTI)

This paper focuses on the simulation research to fuel oil system. Hydrodynamic analysis to fuel oil system pipelines network is done and the modeling method is using finite element theory. A relative accepted ...

Diyang Li; Yuan Jiang; Boyang Li

2012-01-01T23:59:59.000Z

16

Determination of fracture toughness of AZ31 Mg alloy using the cohesive finite element method  

E-Print Network [OSTI]

Determination of fracture toughness of AZ31 Mg alloy using the cohesive finite element method X Received in revised form 21 June 2012 Accepted 11 August 2012 Keywords: Fracture toughness Cohesive finite is to develop a micromechanical approach for determining the fracture toughness. A phase-field model for grain

Chen, Long-Qing

17

A VECTOR FINITE ELEMENT TIME-DOMAIN METHOD FOR ...  

E-Print Network [OSTI]

gential continuity across interfaces whereas the face elements have normal continuity ..... Example: Numerical dispersion for three-dimensional shear distortion. Let ..... The error measure is the standard L2 relative error shown below,.

SIAM (#1) 1035 2001 Apr 10 12:32:38

2001-08-14T23:59:59.000Z

18

Computing the dynamics of biomembranes by combining conservative level set and adaptive finite element methods  

Science Journals Connector (OSTI)

The numerical simulation of the deformation of vesicle membranes under simple shear external fluid flow is considered in this paper. A saddle-point approach is proposed for the imposition of the fluid incompressibility and the membrane inextensibility ... Keywords: Adaptive finite element method, Fluid mechanics, Helfrich energy, Level set method, Mass conservation, Vesicle dynamics

Aymen Laadhari, Pierre Saramito, Chaouqi Misbah

2014-04-01T23:59:59.000Z

19

Mixed finite element methods for incompressible flow: Stationary ...  

E-Print Network [OSTI]

May 14, 2009 ... 0, (conservation of mass) ... Contract grant sponsor: U.S. Department of Energy by University of California .... We use the standard notations and definitions for the Sobolev ...... minimum residual method applied to the system.

2010-04-14T23:59:59.000Z

20

Computation of incompressible bubble dynamics with a stabilized finite element level set method  

E-Print Network [OSTI]

Computation of incompressible bubble dynamics with a stabilized finite element level set method. 100 (1992) 335­354] was applied in order to account for surface tension effects. To restrict as surface tension. The capability of the resultant algorithm is demonstrated with two and three dimensional

Frey, Pascal

Note: This page contains sample records for the topic "finite element method" 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

Deforming fluid domains within the finite element method: Five mesh-based tracking methods in comparison  

E-Print Network [OSTI]

Fluid flow applications can involve a number of coupled problems. One is the simulation of free-surface flows, which require the solution of a free-boundary problem. Within this problem, the governing equations of fluid flow are coupled with a domain deformation approach. This work reviews five of those approaches: interface tracking using a boundary-conforming mesh and, in the interface capturing context, the level-set method, the volume-of-fluid method, particle methods, as well as the phase-field method. The history of each method is presented in combination with the most recent developments in the field. Particularly, the topics of extended finite elements (XFEM) and NURBS-based methods, such as Isogeometric Analysis (IGA), are addressed. For illustration purposes, two applications have been chosen: two-phase flow involving drops or bubbles and sloshing tanks. The challenges of these applications, such as the geometrically correct representation of the free surface or the incorporation of surface tension ...

Elgeti, Stefanie

2015-01-01T23:59:59.000Z

22

Three dimensional finite element methods: Their role in the design of DC accelerator systems  

SciTech Connect (OSTI)

High Voltage Engineering has designed, built and tested a 2 MV dual irradiation system that will be applied for radiation damage studies and ion beam material modification. The system consists of two independent accelerators which support simultaneous proton and electron irradiation (energy range 100 keV - 2 MeV) of target sizes of up to 300 Multiplication-Sign 300 mm{sup 2}. Three dimensional finite element methods were used in the design of various parts of the system. The electrostatic solver was used to quantify essential parameters of the solid-state power supply generating the DC high voltage. The magnetostatic solver and ray tracing were used to optimize the electron/ion beam transport. Close agreement between design and measurements of the accelerator characteristics as well as beam performance indicate the usefulness of three dimensional finite element methods during accelerator system design.

Podaru, Nicolae C.; Gottdang, A.; Mous, D. J. W. [High Voltage Engineering Europa B.V., P.O. Box 99, 3800 AB, Amersfoort (Netherlands)

2013-04-19T23:59:59.000Z

23

An error analysis of a finite element method for a system of nonlinear advection--diffusion--reaction equations  

Science Journals Connector (OSTI)

In this paper we present an analysis of a finite element method for solving a system of nonlinear advection-diffusion-reaction equations. We prove the existence and uniqueness of the numerical solution, and obtain a prior error estimates optimal in H^1 ... Keywords: Advection--diffusion--reaction, Error estimate, Finite element, Nonlinear

Biyue Liu

2009-08-01T23:59:59.000Z

24

An h-adaptive finite element method for turbulent heat transfer  

SciTech Connect (OSTI)

A two-equation turbulence closure model (k-{omega}) using an h-adaptive grid technique and finite element method (FEM) has been developed to simulate low Mach flow and heat transfer. These flows are applicable to many flows in engineering and environmental sciences. Of particular interest in the engineering modeling areas are: combustion, solidification, and heat exchanger design. Flows for indoor air quality modeling and atmospheric pollution transport are typical types of environmental flows modeled with this method. The numerical method is based on a hybrid finite element model using an equal-order projection process. The model includes thermal and species transport, localized mesh refinement (h-adaptive) and Petrov-Galerkin weighting for the stabilizing the advection. This work develops the continuum model of a two-equation turbulence closure method. The fractional step solution method is stated along with the h-adaptive grid method (Carrington and Pepper, 2002). Solutions are presented for 2d flow over a backward-facing step.

Carriington, David B [Los Alamos National Laboratory

2009-01-01T23:59:59.000Z

25

Higher-order adaptive finite-element methods for Kohn–Sham density functional theory  

SciTech Connect (OSTI)

We present an efficient computational approach to perform real-space electronic structure calculations using an adaptive higher-order finite-element discretization of Kohn–Sham density-functional theory (DFT). To this end, we develop an a priori mesh-adaption technique to construct a close to optimal finite-element discretization of the problem. We further propose an efficient solution strategy for solving the discrete eigenvalue problem by using spectral finite-elements in conjunction with Gauss–Lobatto quadrature, and a Chebyshev acceleration technique for computing the occupied eigenspace. The proposed approach has been observed to provide a staggering 100–200-fold computational advantage over the solution of a generalized eigenvalue problem. Using the proposed solution procedure, we investigate the computational efficiency afforded by higher-order finite-element discretizations of the Kohn–Sham DFT problem. Our studies suggest that staggering computational savings—of the order of 1000-fold—relative to linear finite-elements can be realized, for both all-electron and local pseudopotential calculations, by using higher-order finite-element discretizations. On all the benchmark systems studied, we observe diminishing returns in computational savings beyond the sixth-order for accuracies commensurate with chemical accuracy, suggesting that the hexic spectral-element may be an optimal choice for the finite-element discretization of the Kohn–Sham DFT problem. A comparative study of the computational efficiency of the proposed higher-order finite-element discretizations suggests that the performance of finite-element basis is competing with the plane-wave discretization for non-periodic local pseudopotential calculations, and compares to the Gaussian basis for all-electron calculations to within an order of magnitude. Further, we demonstrate the capability of the proposed approach to compute the electronic structure of a metallic system containing 1688 atoms using modest computational resources, and good scalability of the present implementation up to 192 processors.

Motamarri, P. [Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States)] [Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Nowak, M.R. [Department of Electrical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States)] [Department of Electrical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States); Leiter, K.; Knap, J. [U.S. Army Research Labs, Aberdeen Proving Ground, Aberdeen, MD 21001 (United States)] [U.S. Army Research Labs, Aberdeen Proving Ground, Aberdeen, MD 21001 (United States); Gavini, V., E-mail: vikramg@umich.edu [Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109 (United States)

2013-11-15T23:59:59.000Z

26

Simulation of the ultrasonic array response from real branched cracks using an efficient finite element method  

SciTech Connect (OSTI)

A hybrid model to simulate the ultrasonic array response from stress corrosion cracks is presented. These cracks are branched and difficult to detect so the model is required to enable optimization of an array design. An efficient frequency-domain finite element method is described and selected to simulate the ultrasonic scattering. Experimental validation results are presented, followed by an example of the simulated ultrasonic array response from a real stress corrosion crack whose geometry is obtained from an X-ray Computed Tomography image. A simulation-assisted array design methodology, which includes the model and use of real crack geometries, is proposed.

Felice, Maria V. [Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR, United Kingdom and Rolls-Royce plc., Bristol BS34 7QE (United Kingdom); Velichko, Alexander; Wilcox, Paul D. [Department of Mechanical Engineering, University of Bristol, Bristol BS8 1TR (United Kingdom); Barden, Tim J.; Dunhill, Tony K. [Rolls-Royce plc., Bristol BS34 7QE (United Kingdom)

2014-02-18T23:59:59.000Z

27

Optimal design of switched reluctance motor using two-dimensional finite element method  

Science Journals Connector (OSTI)

Switched reluctance motor (SRM) has some advantages such as low cost high torque density etc. but SRM has essentially high torque ripple due to its salient structure. To apply SRM to the industrial field we have to minimize torque ripple which is the weak point of SRM. This article introduces optimal design process of SRM using a numerical method such as two-dimensional (2D) finite element method. The electrical and geometrical design parameters have been adopted as 2D design variables. From this work we can obtain the optimal design which minimizes the torque ripple. We also can obtain the optimal design which maximizes the average torque. Finally this article presents performance comparison of two optimal designs the minimized torque ripple and the maximized average torque.

Youn-Hyun Kim; Jae-Hak Choi; Sung-In Jung; Sol Kim; Ju Lee; Min-Sik Chu; Kyung-Jin Hong; Dong-Hoon Choi

2002-01-01T23:59:59.000Z

28

A semi-implicit finite element method for viscous lipid membranes  

E-Print Network [OSTI]

We propose a robust simulation method for phospholipid membranes. It is based on a mixed three-field formulation that accounts for tangential fluidity (Boussinesq-Scriven law), bending elasticity (Canham-Helfrich model) and inextensibility. The unknowns are the velocity, vector curvature and surface pressure fields, all of which are interpolated with linear continuous finite elements. The method is semi-implicit - it requires the solution of a single linear system per time step. Conditional time stability is observed, with a time step restriction that scales as the square of the mesh size. Mesh quality and refinement are maintained by adaptively remeshing. Another ingredient is a numerical force that emulates the action of an optical tweezer, allowing for virtual interaction with the membrane. Extensive relaxation experiments are reported. Comparisons to exact shapes reveal the orders of convergence for position (5/3), vector curvature (3/2), surface pressure (1) and bending energy (2). Tweezing experiments a...

Rodrigues, Diego S; Mut, Fernando; Buscaglia, Gustavo C

2014-01-01T23:59:59.000Z

29

Parallel Computations of Natural Convection Flow in a Tall Cavity Using an Explicit Finite Element Method  

SciTech Connect (OSTI)

The Galerkin Finite Element Method was used to predict a natural convection flow in an enclosed cavity. The problem considered was a differentially heated, tall (8:1), rectangular cavity with a Rayleigh number of 3.4 x 10{sup 5} and Prandtl number of 0.71. The incompressible Navier-Stokes equations were solved using a Boussinesq approximation for the buoyancy force. The algorithm was developed for efficient use on massively parallel computer systems. Emphasis was on time-accurate simulations. It was found that the average temperature and velocity values can be captured with a relatively coarse grid, while the oscillation amplitude and period appear to be grid sensitive and require a refined computation.

Dunn, T.A.; McCallen, R.C.

2000-10-17T23:59:59.000Z

30

An angularly refineable phase space finite element method with approximate sweeping procedure  

SciTech Connect (OSTI)

An angularly refineable phase space finite element method is proposed to solve the neutron transport equation. The method combines the advantages of two recently published schemes. The angular domain is discretized into small patches and patch-wise discontinuous angular basis functions are restricted to these patches, i.e. there is no overlap between basis functions corresponding to different patches. This approach yields block diagonal Jacobians with small block size and retains the possibility for S{sub n}-like approximate sweeping of the spatially discontinuous elements in order to provide efficient preconditioners for the solution procedure. On the other hand, the preservation of the full FEM framework (as opposed to collocation into a high-order S{sub n} scheme) retains the possibility of the Galerkin interpolated connection between phase space elements at arbitrary levels of discretization. Since the basis vectors are not orthonormal, a generalization of the Riemann procedure is introduced to separate the incoming and outgoing contributions in case of unstructured meshes. However, due to the properties of the angular discretization, the Riemann procedure can be avoided at a large fraction of the faces and this fraction rapidly increases as the level of refinement increases, contributing to the computational efficiency. In this paper the properties of the discretization scheme are studied with uniform refinement using an iterative solver based on the S{sub 2} sweep order of the spatial elements. The fourth order convergence of the scalar flux is shown as anticipated from earlier schemes and the rapidly decreasing fraction of required Riemann faces is illustrated. (authors)

Kophazi, J.; Lathouwers, D. [Faculty of Applied Sciences, Delft University of Technology, Mekelweg 15, NL-2629 JB Delft (Netherlands)

2013-07-01T23:59:59.000Z

31

Fourier-Finite Element Method with linear basis functions on the sphere: Application to elliptic- and transport-equations  

Science Journals Connector (OSTI)

Fourier-Finite Element Method (FFEM) on the sphere, which performs with operation count of O(N2 log2 N) for 2N × N grids in spherical coordinates, was developed using linear basis functions. Dependent field variables are expanded with the Fourier ...

Hyeong-Bin Cheong; Hae-Jin Kong; Hyun-Gyu Kang; Jae-Deok Lee

32

Application of equivalent elastic methods in three-dimensional finite element structural analysis  

SciTech Connect (OSTI)

This paper describes use of equivalent solid (EQS) modeling to obtain efficient solutions to perforated material problems using three-dimensional finite element analysis (3-D-FEA) programs. It is shown that EQS modeling in 3-D-FEA requires an EQS constitutive relationship with a sufficient number of independent constants to allow the EQS material to respond according to the elastic symmetry of the penetration pattern. It is also shown that a 3-D-FEA submodel approach to calculate peak stresses and ligament stresses from EQS results is very accurate and preferred over more traditional stress multiplier approaches. The method is demonstrated on the problem of a transversely pressurized simply supported plate with a central divider lane separating two perforated regions with circular penetrations arranged in a square pattern. A 3-D-FEA solution for a model that incorporates each penetration explicitly is used for comparison with results from an EQS solution for the plate. Results for deflection and stresses from the EQS solution are within 3% of results from the explicit 3-D-FE model. A solution to the sample problem is also provided using the procedures in the ASME B and PV Code. The ASME B and PV Code formulas for plate deflection were shown to overestimate the stiffening effects of the divider lane and the outer stiffening ring.

Jones, D.P.; Gordon, J.L.; Hutula, D.N.; Holliday, J.E.; Jandrasits, W.G. [Bechtel Bettis, Inc., West Mifflin, PA (United States). Bettis Atomic Power Lab.

1999-08-01T23:59:59.000Z

33

Sensitivity analysis of single-layer graphene resonators using atomic finite element method  

SciTech Connect (OSTI)

Atomic finite element simulation is applied to study the natural frequency and sensitivity of a single-layer graphene-based resonator with CCCC, SSSS, CFCF, SFSF, and CFCF boundary conditions using the commercial code ANSYS. The fundamental frequencies of the graphene sheet are compared with the results of the previous finite element study. In addition, the sensitivity of the resonator is compared with the early work based on nonlocal elasticity theory. The results of the comparison are very good in all considered cases. The sensitivities of the resonator with different boundary conditions are obtained, and the order based on the boundary condition is CCCC > SSSS > CFCF > SFSF > CFFF. The highest sensitivity is obtained when the attached mass is located at the center of the resonator. This is useful for the design of a highly sensitive graphene-based mass sensor.

Lee, Haw-Long; Hsu, Jung-Chang; Lin, Shu-Yu; Chang, Win-Jin [Department of Mechanical Engineering, Kun Shan University, Tainan 71003, Taiwan (China)] [Department of Mechanical Engineering, Kun Shan University, Tainan 71003, Taiwan (China)

2013-09-28T23:59:59.000Z

34

Efficient periodic band diagram computation using a finite element method, Arnoldi eigensolver and sparse linear system solver  

E-Print Network [OSTI]

We present here a Finite Element Method devoted to the simulation of 3D periodic structures of arbitrary geometry. The numerical method based on ARPACK and PARDISO libraries, is discussed with the aim of extracting the eigenmodes of periodical structures and thus establishing their frequency band gaps. Simulation parameters and the computational optimization are the focus. Resolution will be used to characterize EBG (Electromagnetic Band Gap) structures, such as plasma rods and metallic cubes.

Garnier, Romain; Pascal, Olivier

2014-01-01T23:59:59.000Z

35

Dynamic analysis of shells of revolution submerged in an acoustic medium by the finite element method  

E-Print Network [OSTI]

of the spherical shell transformation matrix relating (q} and (u) for an element generalized added mass matrix due to radiated pressure matrix relating (q) and (I) for an element unknown source strength velocity of sound in fluid coupled equivalent nodal load... A method 1s presented for the evaluation of the displacements and the surface pressure which are induced by the harmonic exc1tation of a shell of revolution submerged in an acoustic medium. The method utilizes a source distribution approach...

Ng, Chi Kin

1978-01-01T23:59:59.000Z

36

Virtual dynamic balancing method without trial weights for multi-rotor series shafting based on finite element model analysis  

Science Journals Connector (OSTI)

The traditional influence coefficient dynamic balancing method for multi-rotor series shafting such as turbine-generator sets gas turbines compressor trains and others usually needs to startup many times using trial weights along the rotor. Based on finite element model analysis for the multi-rotor series shafting a virtual dynamic balancing methodology which only needs to collect data of vibration response at operating speed without trial weights is developed in this paper. According to shafting structure and operating parameters the dynamic finite element model was built by using rotor dynamics theory and finite element simulation technology. The shafting dynamic characteristics and weighted influence coefficient matrix can be gotten by exciting virtual unbalance force on the balance place correspondingly. The effectiveness and flexibility of the proposed method have been illustrated by solving a shafting dynamic balancing example with no trial weights requirements. It is believed that the new methods developed in this work will help in reducing the time and cost of the equipment manufacturer or field dynamic balancing procedures.

2014-01-01T23:59:59.000Z

37

Numerical Stochastic Homogenization Method and Multiscale Stochastic Finite Element Method - A Paradigm for Multiscale Computation of Stochastic PDEs  

SciTech Connect (OSTI)

Multiscale modeling of stochastic systems, or uncertainty quantization of multiscale modeling is becoming an emerging research frontier, with rapidly growing engineering applications in nanotechnology, biotechnology, advanced materials, and geo-systems, etc. While tremendous efforts have been devoted to either stochastic methods or multiscale methods, little combined work had been done on integration of multiscale and stochastic methods, and there was no method formally available to tackle multiscale problems involving uncertainties. By developing an innovative Multiscale Stochastic Finite Element Method (MSFEM), this research has made a ground-breaking contribution to the emerging field of Multiscale Stochastic Modeling (MSM) (Fig 1). The theory of MSFEM basically decomposes a boundary value problem of random microstructure into a slow scale deterministic problem and a fast scale stochastic one. The slow scale problem corresponds to common engineering modeling practices where fine-scale microstructure is approximated by certain effective constitutive constants, which can be solved by using standard numerical solvers. The fast scale problem evaluates fluctuations of local quantities due to random microstructure, which is important for scale-coupling systems and particularly those involving failure mechanisms. The Green-function-based fast-scale solver developed in this research overcomes the curse-of-dimensionality commonly met in conventional approaches, by proposing a random field-based orthogonal expansion approach. The MSFEM formulated in this project paves the way to deliver the first computational tool/software on uncertainty quantification of multiscale systems. The applications of MSFEM on engineering problems will directly enhance our modeling capability on materials science (composite materials, nanostructures), geophysics (porous media, earthquake), biological systems (biological tissues, bones, protein folding). Continuous development of MSFEM will further contribute to the establishment of Multiscale Stochastic Modeling strategy, and thereby potentially to bring paradigm-shifting changes to simulation and modeling of complex systems cutting across multidisciplinary fields.

X. Frank Xu

2010-03-30T23:59:59.000Z

38

A Full-wave Model for Wave Propagation and Dissipation in the Inner Magnetosphere Using the Finite Element Method  

SciTech Connect (OSTI)

A wide variety of plasma waves play an important role in the energization and loss of particles in the inner magnetosphere. Our ability to understand and model wave-particle interactions in this region requires improved knowledge of the spatial distribution and properties of these waves as well as improved understanding of how the waves depend on changes in solar wind forcing and/or geomagnetic activity. To this end, we have developed a two-dimensional, finite element code that solves the full wave equations in global magnetospheric geometry. The code describes three-dimensional wave structure including mode conversion when ULF, EMIC, and whistler waves are launched in a two-dimensional axisymmetric background plasma with general magnetic field topology. We illustrate the capabilities of the code by examining the role of plasmaspheric plumes on magnetosonic wave propagation; mode conversion at the ion-ion and Alfven resonances resulting from external, solar wind compressions; and wave structure and mode conversion of electromagnetic ion cyclotron waves launched in the equatorial magnetosphere, which propagate along the magnetic field lines toward the ionosphere. We also discuss advantages of the finite element method for resolving resonant structures, and how the model may be adapted to include nonlocal kinetic effects.

Ernest Valeo, Jay R. Johnson, Eun-Hwa and Cynthia Phillips

2012-03-13T23:59:59.000Z

39

Hypersonic Heat Transfer and Anisotropic Visualization with a Higher Order Discontinuous Galerkin Finite Element Method  

E-Print Network [OSTI]

Hypersonic Heat Transfer and Anisotropic Visualization with a Higher Order Discontinuous Galerkin;Hypersonic Heat Transfer and Anisotropic Visualization with a Higher Order Discontinuous Galerkin Finite used to predict heat transfer to a cylinder in a hypersonic flow. The strong shock is captured

Peraire, Jaime

40

Calculation of demagnetization curves of NdFeB-magnets using the finite-element-method  

SciTech Connect (OSTI)

A method is developed, which allows to investigate the influence of magnetostatic coupling of structural details on the demagnetization curve within a two dimensional model. In contrast to former methods, which assigned to each grain one value of magnetic field and one value of nucleation field only, this method takes into account the spatial distribution of these fields. It considers not only the coupling between adjacent grains but also the effect of distant grains. The nucleation fields along the boundary of the grains are generated by a statistical method. The magnetic field is calculated by FEM.

Binner, A.; Roth, S.; Stiller, C. [Inst. fuer Festkoerper- und Werkstofforschung Dresden e.V (Germany)] [Inst. fuer Festkoerper- und Werkstofforschung Dresden e.V (Germany)

1994-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

The piecewise linear discontinuous finite element method applied to the RZ and XYZ transport equations  

E-Print Network [OSTI]

on our discretized system for both geometries. This analysis predicts that the PWLD method will perform well in this limit for many problems of physical interest with arbitrary polygonal and polyhedral cells. Finally, we run a series of test problems... ......................................... 75 Asymptotic analysis and the thick diffusive limit.......................... 78 Diffusion limit analysis of the boundary cells ............................... 100 Lumping in RZ geometry...

Bailey, Teresa S

2008-10-10T23:59:59.000Z

42

A Matlab mesh generator for the two-dimensional finite element method  

Science Journals Connector (OSTI)

Abstract A new Matlab code for the generation of unstructured (3-node or 6-node) triangular meshes in two dimensions is proposed. The method is based on the Matlab mesh generator distmesh of Persson and Strang (2004). As input, the code takes a signed distance function for the domain geometry. A mesh size function, for the spatial node distribution, is constructed using an approximate medial axis. As outputs, the code generates a 3-node or a 6-node triangular mesh with boundary data (edges and nodes). The approach presented consists of three steps: (1) an initial nodes placement is obtained using a probabilistic node distribution, (2) an iterative smoothing is performed assuming the presence of an attractive/repulsive internode force, and (3) a fast refinement procedure is performed for 6-node triangular meshes or large scale meshes.

Jonas Koko

2015-01-01T23:59:59.000Z

43

Finite element training before real analysis: A personal view  

Science Journals Connector (OSTI)

In finite element structural analysis, we have the dilemma that an engineer can solve a very complex problem using multi-million dollar software on high-technology hardware with beautifully coloured pictures of the results, without knowing the fundamentals of the finite element method. In this paper the author presents a personal view of how this dilemma should be resolved. His solution emphasises the crucial importance of standards, quality assurance, reliability and, above all, education and training in finite element analysis.

John Robinson

1994-01-01T23:59:59.000Z

44

14th Finite Element Workshop --Ulm, July 2007 Finite Element Simulation  

E-Print Network [OSTI]

of Bonn, {martin.rumpf,ole.schwen}@ins.uni-bonn.de 1 #12;CT segment CFE Figure 1: The image based of the composite finite element (CFE) concept first introduced in [22, 23]. The main idea is to incorporate and corresponding geometric multigrid solvers. After a review of related methods, we explain the CFE method

Rumpf, Martin

45

A posteriori error estimates for mixed finite element and finite volume methods for problems coupled through a boundary with nonmatching grids  

Science Journals Connector (OSTI)

......October 2014 research-article Articles A posteriori error estimates for mixed finite...volume methods for problems coupled through a boundary with nonmatching grids T. Arbogast...adjoining domains sharing boundary conditions on a common boundary interface in the important......

T. Arbogast; D. Estep; B. Sheehan; and S. Tavener

2014-10-01T23:59:59.000Z

46

A weighted reverse Cuthill-McKee procedure for finite element method algorithms to solve strongly anisotropic electrodynamic problems  

SciTech Connect (OSTI)

This paper presents a technique for improving the convergence rate of a generalized minimum residual (GMRES) algorithm applied for the solution of a algebraic system produced by the discretization of an electrodynamic problem with a tensorial electrical conductivity. The electrodynamic solver considered in this work is a part of a magnetohydrodynamic (MHD) code in the low magnetic Reynolds number approximation. The code has been developed for the analysis of MHD interaction during the re-entry phase of a space vehicle. This application is a promising technique intensively investigated for the shock mitigation and the vehicle control in the higher layers of a planetary atmosphere. The medium in the considered application is a low density plasma, characterized by a tensorial conductivity. This is a result of the behavior of the free electric charges, which tend to drift in a direction perpendicular both to the electric field and to the magnetic field. In the given approximation, the electrodynamics is described by an elliptical partial differential equation, which is solved by means of a finite element approach. The linear system obtained by discretizing the problem is solved by means of a GMRES iterative method with an incomplete LU factorization threshold preconditioning. The convergence of the solver appears to be strongly affected by the tensorial characteristic of the conductivity. In order to deal with this feature, the bandwidth reduction in the coefficient matrix is considered and a novel technique is proposed and discussed. First, the standard reverse Cuthill-McKee (RCM) procedure has been applied to the problem. Then a modification of the RCM procedure (the weighted RCM procedure, WRCM) has been developed. In the last approach, the reordering is performed taking into account the relation between the mesh geometry and the magnetic field direction. In order to investigate the effectiveness of the methods, two cases are considered. The RCM and WRCM procedures has successfully improved the convergence rate of the GMRES solver. For strong anisotropies, the WRCM procedure appears to have a higher convergence rate. The same behavior is shown when applying the methods to the rebuilding of an hypersonic MHD experiment.

Cristofolini, Andrea; Latini, Chiara; Borghi, Carlo A. [Department of Electrical Engineering, University of Bologna, Viale Risorgimento 2, 40136 Bologna (Italy)

2011-02-01T23:59:59.000Z

47

Mixed finite elements for global tide models  

E-Print Network [OSTI]

We study mixed finite element methods for the linearized rotating shallow water equations with linear drag and forcing terms. By means of a strong energy estimate for an equivalent second-order formulation for the linearized momentum, we prove long-time stability of the system without energy accumulation -- the geotryptic state. A priori error estimates for the linearized momentum and free surface elevation are given in $L^2$ as well as for the time derivative and divergence of the linearized momentum. Numerical results confirm the theoretical results regarding both energy damping and convergence rates.

Cotter, Colin J

2014-01-01T23:59:59.000Z

48

Finite Element Analysis of Marine Diesel Engine Crankshaft  

Science Journals Connector (OSTI)

In this paper, with the ANSYS, stress distribution and safety factor of crankshaft were analyzed by using 3D finite element method. The results show that the exposed destructive position is the transition circ...

Bin Zheng; Yongqi Liu; Ruixiang Liu…

2011-01-01T23:59:59.000Z

49

Climbing elements in finite coxeter groups  

E-Print Network [OSTI]

We define the notion of a climbing element in a finite real reflection group relative to a total order on the reflection set and we characterise these elements in the case where the total order arises from a bipartite Coxeter element.

Brady, Thomas; Watt, And Colum

2010-01-01T23:59:59.000Z

50

Finite element analysis of multilayer coextrusion.  

SciTech Connect (OSTI)

Multilayer coextrusion has become a popular commercial process for producing complex polymeric products from soda bottles to reflective coatings. A numerical model of a multilayer coextrusion process is developed based on a finite element discretization and two different free-surface methods, an arbitrary-Lagrangian-Eulerian (ALE) moving mesh implementation and an Eulerian level set method, to understand the moving boundary problem associated with the polymer-polymer interface. The goal of this work is to have a numerical capability suitable for optimizing and troubleshooting the coextrusion process, circumventing flow instabilities such as ribbing and barring, and reducing variability in layer thickness. Though these instabilities can be both viscous and elastic in nature, for this work a generalized Newtonian description of the fluid is used. Models of varying degrees of complexity are investigated including stability analysis and direct three-dimensional finite element free surface approaches. The results of this work show how critical modeling can be to reduce build test cycles, improve material choices, and guide mold design.

Hopkins, Matthew Morgan; Schunk, Peter Randall; Baer, Thomas A. (Proctor & Gamble Company, West Chester, OH); Mrozek, Randy A. (Army Research Laboratory, Adelphi, MD); Lenhart, Joseph Ludlow (Army Research Laboratory, Adelphi, MD); Rao, Rekha Ranjana; Collins, Robert (Oak Ridge National Laboratory); Mondy, Lisa Ann

2011-09-01T23:59:59.000Z

51

Dynamic finite-strain modelling of the human left ventricle in health and disease using an immersed boundary-finite element method  

Science Journals Connector (OSTI)

......grid-converged results, we use the grid spacing x = 0.156 cm for...dynamics. Advanced Computational Infrastructures for Parallel and Distributed...B. E. & Luo, X. Y. Hybrid finite difference/finite...Mesh Refinement Application Infrastructure. Available at http......

Hao Gao; David Carrick; Colin Berry; Boyce E. Griffith; Xiaoyu Luo

2014-10-01T23:59:59.000Z

52

Gauge invariance and the finite-element solution of the Schwinger model  

Science Journals Connector (OSTI)

We apply the method of finite elements to two-dimensional quantum electrodynamics. We construct gauge-invariant operator difference equations and compute the chiral anomaly in the Schwinger model. The relative error between the exact answer and the finite-element prediction vanishes like M-2, where M is the number of finite elements.

Carl M. Bender; Kimball A. Milton; David H. Sharp

1985-01-15T23:59:59.000Z

53

Quadrilateral/hexahedral finite element mesh coarsening  

DOE Patents [OSTI]

A technique for coarsening a finite element mesh ("FEM") is described. This technique includes identifying a coarsening region within the FEM to be coarsened. Perimeter chords running along perimeter boundaries of the coarsening region are identified. The perimeter chords are redirected to create an adaptive chord separating the coarsening region from a remainder of the FEM. The adaptive chord runs through mesh elements residing along the perimeter boundaries of the coarsening region. The adaptive chord is then extracted to coarsen the FEM.

Staten, Matthew L; Dewey, Mark W; Scott, Michael A; Benzley, Steven E

2012-10-16T23:59:59.000Z

54

Parallelization of the Red-Black Algorithm on Solving the Second-Order PN Transport Equation with the Hybrid Finite Element Method  

SciTech Connect (OSTI)

The Red-Black algorithm has been successfully applied on solving the second-order parity transport equation with the PN approximation in angle and the Hybrid Finite Element Method (HFEM) in space, i.e., the Variational Nodal Method (VNM) [1,2,3,4,5]. Any transport solving techniques, including the Red-Black algorithm, need to be parallelized in order to take the advantage of the development of supercomputers with multiple processors for the advanced modeling and simulation. To our knowledge, an attempt [6] was done to parallelize it, but it was devoted only to the z axis plans in three-dimensional calculations. General parallelization of the Red-Black algorithm with the spatial domain decomposition has not been reported in the literature. In this summary, we present our implementation of the parallelization of the Red-Black algorithm and its efficiency results.

Yaqi Wang; Cristian Rabiti; Giuseppe Palmiotti

2011-06-01T23:59:59.000Z

55

mFES: A Robust Molecular Finite Element Solver for Electrostatic Energy Computations  

Science Journals Connector (OSTI)

We present a robust method for the calculation of electrostatic potentials of large molecular systems using tetrahedral finite elements (FE). Compared to the finite difference (FD) method using a regular simple cubic grid to solve the Poisson equation, ...

I. Sakalli; J. Schöberl; E. W. Knapp

2014-10-09T23:59:59.000Z

56

A high-order implicit finite element method for integrating the two-fluid magnetohydrodynamic equations in two dimensions  

Science Journals Connector (OSTI)

We describe a new method for solving the time-dependent two-fluid magnetohydrodynamic (2F-MHD) equations in two dimensions that has significant advantages over other methods. The stream-function/potential representation of the velocity and magnetic field ...

S. C. Jardin; J. Breslau; N. Ferraro

2007-10-01T23:59:59.000Z

57

Rational Wachspress-type Finite Elements on Regular Hexagons  

Science Journals Connector (OSTI)

......Finite Elements on Regular Hexagons J. L. GOUT Departement de Mathematiques, Universite...Finite Elements on Regular Hexagons J. L. GOUT Departement de Mathematiques, Universite...1975) (see also Apprato, Arcangeli & Gout, 1979a, b; Gout, 1979, 1980a, b......

J. L. GOUT

58

GEO+, a finite element program on a personal computer  

E-Print Network [OSTI]

The following study is the first step toward implementation of a complete finite element analysis package on a personal computer for geotechnical engineering problems. A complete finite element analysis has been written in the C/C++ language...

Guillin, Clement Gerard

2012-06-07T23:59:59.000Z

59

E-Print Network 3.0 - advanced finite element Sample Search Results  

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

Institute and Department of Mathematics Summary: .T. Williams, and E. Woodward 1982. Recent advances in the Galerkin finite-element method as applied... A review of...

60

UNIFIED FINITE ELEMENT DISCRETIZATIONS OF COUPLED DARCY-STOKES FLOW  

E-Print Network [OSTI]

by using standard Stokes elements like the MINI element or the Taylor­Hood element in the entire domain elements like the Taylor­Hood element or the MINI element for the Stokes region. The similar approach], to overcome this problem. This finite element space is defined with respect to a rectangular grid. On each

Winther, Ragnar

Note: This page contains sample records for the topic "finite element method" 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

A new finite element lifting surface technique  

E-Print Network [OSTI]

Element Lifting Surface Technique. (May 1973) James David Kocurek, B. S. , Texas ASM University 1 Directed by: Dr. Balusu M. Rao A numerical lifting surface technique based on discrete vortex loading elements is developed for calculating the steady..., incompress- ; ible, aerodynamic load distribution on a general, nonplanar, ideal- 1 ized body. The method, described as the "Vortex Box" technique, has been applied to general planar wings of arbitrary straight line ' geometry and to annular wings...

Kocurek, James David

2012-06-07T23:59:59.000Z

62

A finite element model for transient thermal/structural analysis of large composite space structures  

E-Print Network [OSTI]

on approximate 6 analysis techniques based on finite elements has begun. Such techniques as reduced basis techniques and generalized transform methods offer hope of solving the finite element 8 equations more efficiently. An integrated thermal/structural... integrated analysis codes. However, Mahaney, Thornton, and Dechaumphai have identified require 5 ments for such thermal/structural programs. They concluded that such analysis methods should have the following five characteristics. First, a common finite...

Lutz, James Delmar

2012-06-07T23:59:59.000Z

63

Finite element modeling of nonlinear vibration behavior of piezo-integrated structures  

Science Journals Connector (OSTI)

This paper aims at finite element modeling of nonlinear vibration behavior of piezo-integrated structures subjected to weak electric field. This nonlinear vibration behavior was observed in the form of dependence of resonance frequency on the vibration ... Keywords: Finite element modeling, Modal reduction, Newmark method, Nonlinear vibration, Piezo-integrated structures

Sandeep Kumar Parashar; Utz Von Wagner; Peter Hagedorn

2013-04-01T23:59:59.000Z

64

CharacteristicGalerkin and Mixed Finite Element Approximation of Contamination by Compressible  

E-Print Network [OSTI]

Characteristic­Galerkin and Mixed Finite Element Approximation of Contamination by Compressible­disposal contamination in porous media is modeled by a coupled system of partial differential equations for the brine, radionuclides, and heat and by a mixed finite element method for the pressure and velocity

Chou, So-Hsiang

65

FINITE-ELEMENT FORMULATIONS FOR PROBLEMS OF LARGE ELASTIC-PLASTIC DEFORMATION  

E-Print Network [OSTI]

FINITE-ELEMENT FORMULATIONS FOR PROBLEMS OF LARGE ELASTIC-PLASTIC DEFORMATION R. M. MCM~EKING and J elastic-plastic flow.The method is based on Hill's variational principle for incremental deformations in a manner which allows any conventions finite element program, for "small strain" elastic-plastic analysis

66

Multiscale finite element analysis of elastic wave scattering from localized defects  

Science Journals Connector (OSTI)

This paper investigates the use of a multiscale finite element approach to study the interaction between elastic waves and localized defects. The analysis of wave-defect interaction is of fundamental importance for the development of ultrasonic non-destructive ... Keywords: Elastic wave scattering, Finite element method, Multiscale analysis

F. Casadei, J. J. Rimoli, M. Ruzzene

2014-10-01T23:59:59.000Z

67

A ThreeDimensional Finite Element Simulation for Transport of Nuclear Waste Contamination in Porous Media  

E-Print Network [OSTI]

A Three­Dimensional Finite Element Simulation for Transport of Nuclear Waste Contamination of South Carolina, Columbia, South Carolina ABSTRACT: Model equations for transport of nuclear­waste based up on the inherent physics. A three­dimensional finite element method for nuclear waste

Ewing, Richard E.

68

A mixed finite-element scheme of a semiconductor energy-transport model  

E-Print Network [OSTI]

A mixed finite-element scheme of a semiconductor energy-transport model using dual entropy variables Stephan Gadau, Ansgar J¨ungel, and Paola Pietra Abstract. One-dimensional stationary energy employing a mixed-hybrid finite- element method which has the advantage to fulfill current conser- vation

Hanke-Bourgeois, Martin

69

Algebraic multigrid for stabilized finite element discretizations of the Navier Stokes equation  

E-Print Network [OSTI]

A multilevel method for the solution of systems of equations generated by stabilized Finite Element discretizations of the Euler and Navier Stokes equations on generalized unstructured grids is described. The method is ...

Okusanya, Tolulope Olawale, 1972 -

2002-01-01T23:59:59.000Z

70

Finite element analysis of substation composite insulators  

Science Journals Connector (OSTI)

Composite insulators are rapidly replacing their porcelain counterparts in electrical substation applications. These insulators consist of a glass-reinforced polymer (GRP) rod, with two metal end fittings radially crimped onto the ends of the rod during assembly. In this paper, axisymmetric finite element models are developed to evaluate the mechanical performance of composite insulators under externally applied axial compression. The analyses are performed by assuming both a perfectly bonded interface between the composite rod and the end fittings, and an imperfect interface which permits large relative sliding with Coulomb friction. Results indicate that the perfect interface model is unrealistic since it predicts singular stresses at the interface comer and an overall linear structural response. On the other hand, the imperfect interface model is found to simulate accurately the structural non-linearity caused by relative sliding of the GRP rod within the end fittings. The imperfect interface model has therefore been used to evaluate the effects of interface friction, and the extent of crimping, on the maximum load-bearing capacity of substation composite insulators.

A. Bansal; A. Schubert; M.V. Balakrishnan; M. Kumosa

1995-01-01T23:59:59.000Z

71

Probabilistic finite element modeling of waste rollover  

SciTech Connect (OSTI)

Stratification of the wastes in many Hanford storage tanks has resulted in sludge layers which are capable of retaining gases formed by chemical and/or radiolytic reactions. As the gas is produced, the mechanisms of gas storage evolve until the resulting buoyancy in the sludge leads to instability, at which point the sludge ``rolls over`` and a significant volume of gas is suddenly released. Because the releases may contain flammable gases, these episodes of release are potentially hazardous. Mitigation techniques are desirable for more controlled releases at more frequent intervals. To aid the mitigation efforts, a methodology for predicting of sludge rollover at specific times is desired. This methodology would then provide a rational basis for the development of a schedule for the mitigation procedures. In addition, a knowledge of the sensitivity of the sludge rollovers to various physical and chemical properties within the tanks would provide direction for efforts to reduce the frequency and severity of these events. In this report, the use of probabilistic finite element analyses for computing the probability of rollover and the sensitivity of rollover probability to various parameters is described.

Khaleel, M.A. [Pacific Northwest Lab., Richland, WA (United States); Cofer, W.F.; Al-fouqaha, A.A. [Washington State Univ., Pullman, WA (United States). Dept. of Civil and Environmental Engineering

1995-09-01T23:59:59.000Z

72

Parallel Finite Element Simulation of Tracer Injection in Oil Reservoirs  

E-Print Network [OSTI]

Parallel Finite Element Simulation of Tracer Injection in Oil Reservoirs Alvaro L.G.A. Coutinho In this work, parallel finite element techniques for the simulation of tracer injection in oil reservoirs. Supercomputers have made it possible to consider global reservoir effects which can not be represented using

Coutinho, Alvaro L. G. A.

73

Adaptive strategies using standard and mixed finite elements for wind field adjustment  

SciTech Connect (OSTI)

In order to find a map of wind velocities, this study tries to obtain an incompressible wind field that adjusts to an experimental one: also verifying the corresponding boundary conditions of physical interest. This problem has been solved by several authors using finite differences or standard finite element techniques. In this paper, this problem is solved by two different adaptive finite element methods. The first makes use of standard finite element techniques, using linear interpolation of a potential function. In the second, a direct computation of the velocity field is undertaken by means of a mixed finite element method. Several error indicators are proposed for both formulations together with an adaptive strategy. We have applied both methods to several typical test problems, as well as to realistic data corresponding to the Island of Fuerteventura, with satisfactory results from a numerical point of view. 13 refs., 16 figs., 1 tab.

Winter, G.; Montero, G.; Montenegro, R. [Univ. of Las Palmas de Gran Canaria, FL (United States)] [Univ. of Las Palmas de Gran Canaria, FL (United States)

1995-01-01T23:59:59.000Z

74

An artificial-neural-network method for the identification of saturated turbogenerator parameters based on a coupled finite-element/state-space computational algorithm  

SciTech Connect (OSTI)

An artificial neural network (ANN) is used in the identification of saturated synchronous machine parameters under diverse operating conditions. The training data base for the ANN is generated by a time-stepping coupled finite-element/state-space (CFE-SS) modeling technique which is used in the computation of the saturated parameters of a 20-kV, 733-MVA, 0.85 pf (lagging) turbogenerator at discrete load points in the P-Q capability plane for three different levels of terminal voltage. These computed parameters constitute a learning data base for a multilayer ANN structure which is successfully trained using the back-propagation algorithm. Results indicate that the trained ANN can identify saturated machine reactances for arbitrary load points in the P-Q plane with an error less than 2% of those values obtained directly from the CFE-SS algorithm. Thus, significant savings in computational time are obtained in such parameter computation tasks.

Chaudhry, S.R.; Ahmed-Zaid, S. [Clarkson Univ., Potsdam, NY (United States). Electrical and Computer Engineering Dept.] [Clarkson Univ., Potsdam, NY (United States). Electrical and Computer Engineering Dept.; Demerdash, N.A. [Marquette Univ., Milwaukee, WI (United States). Electrical and Computer Engineering Dept.] [Marquette Univ., Milwaukee, WI (United States). Electrical and Computer Engineering Dept.

1995-12-01T23:59:59.000Z

75

The representation of boundary currents in a finite element shallow water model  

E-Print Network [OSTI]

We evaluate the influence of local resolution, eddy viscosity, coastline structure, and boundary conditions on the numerical representation of boundary currents in a finite element shallow-water model. The use of finite element discretization methods offers a higher flexibility compared to finite difference and finite volume methods, that are mainly used in previous publications. This is true for the geometry of the coast lines and for the realization of boundary conditions. For our investigations we simulate steady separation of western boundary currents from idealized and realistic coast lines. The use of grid refinement allows a detailed investigation of boundary separation at reasonable numerical cost.

Düben, Peter D

2015-01-01T23:59:59.000Z

76

B-spline finite elements for plane elasticity problems  

E-Print Network [OSTI]

. The k-refinement is reported to be much more efficient and robust than the standard h or p- refinement used in the conventional FEM models. Besides the use of B-spline functions for structural problems, they have been used in some other fields as well... and convergence behavior. The paper reports a reduction in the numerical cost using B-spline FEM. The use of the B-spline finite element method for the thermistor problem [29,30] and for a numerical solution of Burger?s equation[31- 33] has been successfully...

Aggarwal, Bhavya

2007-04-25T23:59:59.000Z

77

An operator-customized wavelet-finite element approach for the adaptive solution of second-order partial differential equations on unstructured meshes  

E-Print Network [OSTI]

The Finite Element Method (FEM) is a widely popular method for the numerical solution of Partial Differential Equations (PDE), on multi-dimensional unstructured meshes. Lagrangian finite elements, which preserve C? continuity ...

D'Heedene, Stefan F., 1977-

2005-01-01T23:59:59.000Z

78

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

E-Print Network [OSTI]

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

Gaddamanugu, Dhatri

2010-07-14T23:59:59.000Z

79

Finite element decomposition and grid generation for brain modeling and visualization  

E-Print Network [OSTI]

Numerical grid generation is used to provide a framework for brain and neuron visualization. Smoothing spline surfaces are fit to contour data to generate 3D solid model reconstruction of brain tissues. Finite element methods are then used...

Batte, David Allan

2012-06-07T23:59:59.000Z

80

Finite Element Analysis of Ballistic Penetration of Plain Weave Twaron CT709® Fabrics: A Parametric Study  

E-Print Network [OSTI]

The ballistic impact of Twaron CT709® plain weave fabrics is studied using an explicit finite element method. Many existing approximations pertaining to woven fabrics cannot adequately represent strain rate-dependent behavior exhibited by the Twaron...

Gogineni, Sireesha

2011-10-21T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

FEHM (Finite Element Heat and Mass Transfer Code)  

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

FEHM (Finite Element Heat and Mass Transfer Code) FEHM (Finite Element Heat and Mass Transfer Code) FEHM (Finite Element Heat and Mass Transfer Code) FEHM is used to simulate groundwater and contaminant flow and transport in deep and shallow, fractured and un-fractured porous media throughout the US DOE complex. June 29, 2013 software FEHM is used to simulate groundwater and contaminant flow and transport in deep and shallow, fractured and un-fractured porous media throughout the US DOE complex. Available for thumbnail of Feynman Center (505) 665-9090 Email FEHM (Finite Element Heat and Mass Transfer Code) FEHM is used to simulate groundwater and contaminant flow and transport in deep and shallow, fractured and un-fractured porous media throughout the US DOE complex. FEHM has proved to be a valuable asset on a variety of

82

Finite-element modelling: a new tool for the biologist  

Science Journals Connector (OSTI)

...problem that excessive distortion of the applied skin will prevent adequate adhesion...Finite-element techniques have already been applied to problems associated with cochlear mechanics...position at the University Hospital, Utrecht, The Netherlands, he moved to Bristol...

2000-01-01T23:59:59.000Z

83

Accelerated finite element elastodynamic simulations using the GPU  

SciTech Connect (OSTI)

An approach is developed to perform explicit time domain finite element simulations of elastodynamic problems on the graphical processing unit, using Nvidia's CUDA. Of critical importance for this problem is the arrangement of nodes in memory, allowing data to be loaded efficiently and minimising communication between the independently executed blocks of threads. The initial stage of memory arrangement is partitioning the mesh; both a well established ‘greedy’ partitioner and a new, more efficient ‘aligned’ partitioner are investigated. A method is then developed to efficiently arrange the memory within each partition. The software is applied to three models from the fields of non-destructive testing, vibrations and geophysics, demonstrating a memory bandwidth of very close to the card's maximum, reflecting the bandwidth-limited nature of the algorithm. Comparison with Abaqus, a widely used commercial CPU equivalent, validated the accuracy of the results and demonstrated a speed improvement of around two orders of magnitude. A software package, Pogo, incorporating these developments, is released open source, downloadable from (http://www.pogo-fea.com/) to benefit the community. -- Highlights: •A novel memory arrangement approach is discussed for finite elements on the GPU. •The mesh is partitioned then nodes are arranged efficiently within each partition. •Models from ultrasonics, vibrations and geophysics are run. •The code is significantly faster than an equivalent commercial CPU package. •Pogo, the new software package, is released open source.

Huthwaite, Peter, E-mail: p.huthwaite@imperial.ac.uk

2014-01-15T23:59:59.000Z

84

Surface photovoltage measurements and finite element modeling of SAW devices.  

SciTech Connect (OSTI)

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

Donnelly, Christine

2012-03-01T23:59:59.000Z

85

Approximation of vector fields using discrete div-rot variational splines in a finite element space  

Science Journals Connector (OSTI)

This paper deals with an approximation problem concerning vector fields through the new notion of div-rot variational splines. The minimizing problem is addressed in a finite element space through the choice of some semi-norms based on decomposition ... Keywords: 65D05, 65D07, 65D10, 65D17, Approximation of vector fields, Discrete problem, Finite element, Smoothing, Spline, Variational method

A. Kouibia; M. Pasadas

2014-01-01T23:59:59.000Z

86

A Mixed Finite-Element Discretization of the Energy-Transport Model for Semiconductors  

E-Print Network [OSTI]

A Mixed Finite-Element Discretization of the Energy-Transport Model for Semiconductors Stefan Holst #12;tting mixed #12;nite-element method is used to discretize the stationary energy. Energy-transport models describe the ow of electrons through a semi- conductor device, in uenced by di

Pietra, Paola

87

Finite element structural study of the VGOT wind turbine  

Science Journals Connector (OSTI)

We analyse the implementation of the finite element method to simulate the structural behaviour of the blade-wagons of variable-geometry oval-trajectory (VGOT) Darrieus wind turbines. The key feature of a VGOT machine is that each blade, instead of rotating around a central vertical axis, slides over rails mounted on a wagon formed by a tubular reticulated structure supported by standard train bogies. The structure should be designed to absorb the efforts in the vertical and traverse directions of the railroad due to the aerodynamic loads, the weight of the components and the centrifugal acceleration along the curved tracks. We show some results for the tip deflection and the tip torsion of the blade, the frontal and lateral angle variations in the blade bottom and the Von Misses tensions of five sample beams, all of them in function of the trajectory-length parameter; and some examples of the deformed configuration of the reticulated structure.

Alejandro D. Otero; Fernando L. Ponta

2004-01-01T23:59:59.000Z

88

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

E-Print Network [OSTI]

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

Boyer, Edmond

89

Modified Mini finite element for the Stokes problem in ?2 or ?3  

Science Journals Connector (OSTI)

We analyze a modified version of the Mini finite element (or the Mini* finite element) for the Stokes problem...2 or ?3. The cross?grid element of order one in ?3 is also analyzed. The stability is verified with ...

Yongdeok Kim; Sungyun Lee

90

Dennis, Eberhart, Dulikravich & Radons FINITE ELEMENT SIMULATION OF COOLING  

E-Print Network [OSTI]

). The simulations performed in this study consider ice packs applied to head and neck as well as using a head-cooling1 Dennis, Eberhart, Dulikravich & Radons FINITE ELEMENT SIMULATION OF COOLING OF REALISTIC 3-D Rapid cooling of the brain in the first minutes following the onset of cerebral ischemia

Dennis, Brian

91

Finite element analysis of controlled laser coagulation experiments  

E-Print Network [OSTI]

A mathematical model to predict the effect of laser and tissue parameters on the zone of thermal injury by laser interaction on beef liver is presented. The heat transfer and coagulation process was modeled using a non-linear finite-element model...

Tolat, Nimish Prabodh

2012-06-07T23:59:59.000Z

92

Finite Element Discretization Strategies for the Inverse Electrocardiographic (ECG) Problem  

E-Print Network [OSTI]

Finite Element Discretization Strategies for the Inverse Electrocardiographic (ECG) Problem Dafang electrocardiographic (ECG) problems re- quires the ability to both quantify and minimize approxi- mation errors specifically for the inverse ECG prob- lem. By quantitatively analyzing the connection between the ill

Utah, University of

93

Finite-element method simulation of effects of microstructure, stress state, and interface strength on flow localization and constraint development in Nb/Cr{sub 2}Nb in situ composites  

SciTech Connect (OSTI)

The effects of volume fraction of particles, stress state, and interface strength on the yield strength, flow localization, plastic constraint, and damage development in Nb/Cr{sub 2}Nb in situ composites were investigated by the finite-element method (FEM). The microstructure of the in situ composite was represented in terms of a unit rectangular or square cell containing Cr{sub 2}Nb particles embedded within a solid-solution-alloy matrix. The hard particles were considered to be elastic and isotropic, while the matrix was elastic-plastic, obeying the Ramberg-Osgood constitutive relation. The FEM model was utilized to compute the composite strength, local hydrostatic stress, and plastic strain distributions as functions of volume fraction of particles, stress state, and interface strength. The results were used to elucidate the influence of volume fracture of particles, stress state, and interface property on the development of plastic constraint and damage in Nb/Cr{sub 2}Nb composites.

Lin, G.; Chan, K.S.

1999-12-01T23:59:59.000Z

94

Time-independent hybrid enrichment for finite element solution of transient conduction–radiation in diffusive grey media  

SciTech Connect (OSTI)

We investigate the effectiveness of the partition-of-unity finite element method for transient conduction–radiation problems in diffusive grey media. The governing equations consist of a semi-linear transient heat equation for the temperature field and a stationary diffusion approximation to the radiation in grey media. The coupled equations are integrated in time using a semi-implicit method in the finite element framework. We show that for the considered problems, a combination of hyperbolic and exponential enrichment functions based on an approximation of the boundary layer leads to improved accuracy compared to the conventional finite element method. It is illustrated that this approach can be more efficient than using h adaptivity to increase the accuracy of the finite element method near the boundary walls. The performance of the proposed partition-of-unity method is analyzed on several test examples for transient conduction–radiation problems in two space dimensions.

Mohamed, M. Shadi, E-mail: m.s.mohamed@durham.ac.uk [School of Engineering and Computing Sciences, University of Durham, South Road, Durham DH1 3LE (United Kingdom); Seaid, Mohammed; Trevelyan, Jon [School of Engineering and Computing Sciences, University of Durham, South Road, Durham DH1 3LE (United Kingdom)] [School of Engineering and Computing Sciences, University of Durham, South Road, Durham DH1 3LE (United Kingdom); Laghrouche, Omar [Institute for Infrastructure and Environment, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)] [Institute for Infrastructure and Environment, Heriot-Watt University, Edinburgh EH14 4AS (United Kingdom)

2013-10-15T23:59:59.000Z

95

Calibration under uncertainty for finite element models of masonry monuments  

SciTech Connect (OSTI)

Historical unreinforced masonry buildings often include features such as load bearing unreinforced masonry vaults and their supporting framework of piers, fill, buttresses, and walls. The masonry vaults of such buildings are among the most vulnerable structural components and certainly among the most challenging to analyze. The versatility of finite element (FE) analyses in incorporating various constitutive laws, as well as practically all geometric configurations, has resulted in the widespread use of the FE method for the analysis of complex unreinforced masonry structures over the last three decades. However, an FE model is only as accurate as its input parameters, and there are two fundamental challenges while defining FE model input parameters: (1) material properties and (2) support conditions. The difficulties in defining these two aspects of the FE model arise from the lack of knowledge in the common engineering understanding of masonry behavior. As a result, engineers are unable to define these FE model input parameters with certainty, and, inevitably, uncertainties are introduced to the FE model.

Atamturktur, Sezer,; Hemez, Francois,; Unal, Cetin

2010-02-01T23:59:59.000Z

96

Beyond first-order finite element schemes in micromagnetics  

SciTech Connect (OSTI)

Magnetization dynamics in ferromagnetic materials is ruled by the Landau–Lifshitz–Gilbert equation (LLG). Reliable schemes must conserve the magnetization norm, which is a nonconvex constraint, and be energy-decreasing unless there is pumping. Some of the authors previously devised a convergent finite element scheme that, by choice of an appropriate test space – the tangent plane to the magnetization – reduces to a linear problem at each time step. The scheme was however first-order in time. We claim it is not an intrinsic limitation, and the same approach can lead to efficient micromagnetic simulation. We show how the scheme order can be increased, and the nonlocal (magnetostatic) interactions be tackled in logarithmic time, by the fast multipole method or the non-uniform fast Fourier transform. Our implementation is called feeLLGood. A test-case of the National Institute of Standards and Technology is presented, then another one relevant to spin-transfer effects (the spin-torque oscillator)

Kritsikis, E., E-mail: kritsikis@math.univ-paris13.fr [Laboratoire d'analyse, géométrie et applications, université Paris 13, CNRS UMR 7539, 93430 Villetaneuse (France); Vaysset, A.; Buda-Prejbeanu, L.D. [SPINTEC, INAC, UMR CEA/CNRS/UJF-Grenoble 1/Grenoble-INP, F-38054 Grenoble (France)] [SPINTEC, INAC, UMR CEA/CNRS/UJF-Grenoble 1/Grenoble-INP, F-38054 Grenoble (France); Alouges, F. [CMAP, CNRS and École polytechnique, F-91128 Palaiseau (France)] [CMAP, CNRS and École polytechnique, F-91128 Palaiseau (France); Toussaint, J.-C. [Institut Néel, CNRS and université Joseph Fourier, F-38042 Grenoble (France)] [Institut Néel, CNRS and université Joseph Fourier, F-38042 Grenoble (France)

2014-01-01T23:59:59.000Z

97

Periodic Boundary Conditions in the ALEGRA Finite Element Code  

SciTech Connect (OSTI)

This document describes the implementation of periodic boundary conditions in the ALEGRA finite element code. ALEGRA is an arbitrary Lagrangian-Eulerian multi-physics code with both explicit and implicit numerical algorithms. The periodic boundary implementation requires a consistent set of boundary input sets which are used to describe virtual periodic regions. The implementation is noninvasive to the majority of the ALEGRA coding and is based on the distributed memory parallel framework in ALEGRA. The technique involves extending the ghost element concept for interprocessor boundary communications in ALEGRA to additionally support on- and off-processor periodic boundary communications. The user interface, algorithmic details and sample computations are given.

AIDUN,JOHN B.; ROBINSON,ALLEN C.; WEATHERBY,JOE R.

1999-11-01T23:59:59.000Z

98

Piezoelectric theory for finite element analysis of ultrasonic motors  

SciTech Connect (OSTI)

The authors present the fundamental equations of piezoelectricity and references. They show how a second form of the equations and a second set of coefficients can be found, through inversions involving the elasticity tensor. They show how to compute the clamped permittivity matrix from the unclamped matrix. The authors list the program pzansys.ftn and present examples of its use. This program does the conversions and calculations needed by the finite element program ANSYS.

Emery, J.D.; Mentesana, C.P.

1997-06-01T23:59:59.000Z

99

Guaranteed Verification of Finite Element Solutions of Heat Conduction  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . . . 1 1.2 Research goals . . . . . . . . . . . . . . . . . . . . . . . . . 3 1.3 Outline of the dissertation . . . . . . . . . . . . . . . . . . 4 II A POSTERIORI ERROR ESTIMATION OF A THERMAL BATTERY PROBLEM WITH HIGH ORTHOTROPY . . . . . 5 2....1 Thermal battery problem and its finite element solution . . 5 2.2 Upper and lower bounds based on residual estimators . . . 12 III ILLUSTRATION OF THE MAIN DIFFICULTY . . . . . . . . 31 3.1 Model problem with boundary layer . . . . . . . . . . . . . 31...

Wang, Delin

2012-07-16T23:59:59.000Z

100

On the role of boundary conditions for CIP stabilization of higher order finite elements  

E-Print Network [OSTI]

On the role of boundary conditions for CIP stabilization of higher order finite elements Friedhelm Schieweck 13.11.2007 Abstract We investigate the Continuous Interior Penalty (CIP) stabilization method even in the limit case where the parameter of the CIP stabilization is zero, i.e., where the standard

Schieweck, Friedhelm

Note: This page contains sample records for the topic "finite element method" 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

3-D Finite Element Analyses of the Egan Cavern Field  

SciTech Connect (OSTI)

Three-dimensional finite element analyses were performed for the two gas-filled storage caverns at the Egan field, Jennings dome, Louisiana. The effects of cavern enlargement on surface subsidence, storage loss, and cavern stability were investigated. The finite element model simulated the leaching of caverns to 6 and 8 billion cubic feet (BCF) and examined their performance at various operating conditions. Operating pressures varied from 0.15 psi/ft to 0.9 psi/ft at the bottom of the lowest cemented casing. The analysis also examined the stability of the web or pillar of salt between the caverns under differential pressure loadings. The 50-year simulations were performed using JAC3D, a three dimensional finite element analysis code for nonlinear quasistatic solids. A damage criterion based on onset of dilatancy was used to evaluate cavern instability. Dilation results from the development of microfractures in salt and, hence, potential increases in permeability onset occurs well before large scale failure. The analyses predicted stable caverns throughout the 50-year period for the range of pressures investigated. Some localized salt damage was predicted near the bottom walls of the caverns if the caverns are operated at minimum pressure for long periods of time. Volumetric cavern closures over time due to creep were moderate to excessive depending on the salt creep properties and operating pressures. However, subsidence above the cavern field was small and should pose no problem, to surface facilities.

Klamerus, E.W.; Ehgartner, B.L.

1999-02-01T23:59:59.000Z

102

Implementation of finite element analysis into the athletic shoe design process  

E-Print Network [OSTI]

Finite element analysis is used by companies throughout the world as a substitution for manually testing prototypes. With the assistance of finite element analysis many companies and industries have decreased the time and ...

Hidalgo, Maria E. (Maria Estela), 1982-

2004-01-01T23:59:59.000Z

103

An evaluation of finite element models of stiffened plates subjected to impulsive loading  

E-Print Network [OSTI]

Different finite element models are evaluated for two very common structures, a cantilever beam and a stiffened plate, subjected to impulsive loading. For the cantilever beam case, the finite element models are one, two ...

Pedatzur, Omri

2004-01-01T23:59:59.000Z

104

On Some Versions of the Element Agglomeration AMGe Method  

SciTech Connect (OSTI)

The present paper deals with element-based AMG methods that target linear systems of equations coming from finite element discretizations of elliptic PDEs. The individual element information (element matrices and element topology) is the main input to construct the AMG hierarchy. We study a number of variants of the spectral agglomerate element based AMG method. The core of the algorithms relies on element agglomeration utilizing the element topology (built recursively from fine to coarse levels). The actual selection of the coarse degrees of freedom (dofs) is based on solving large number of local eigenvalue problems. Additionally, we investigate strategies for adaptive AMG as well as multigrid cycles that are more expensive than the V-cycle utilizing simple interpolation matrices and nested conjugate gradient (CG) based recursive calls between the levels. The presented algorithms are illustrated with an extensive set of experiments based on a matlab implementation of the methods.

Lashuk, I; Vassilevski, P

2007-08-09T23:59:59.000Z

105

We describe predictive load balancing schemes for use with parallel adaptive finite element methods. We provide an overview of an infrastructure suitable  

E-Print Network [OSTI]

balancing methods improve enrichment efficiency and reduce total balancing time by using a priori estimates partition is not sufficient to assure high performance throughout the computation. Dynamic repartitioning is needed to correct for load imbalance introduced by adaptive enrichment. We describe reusable tools

Teresco, James D.

106

Domain decomposition for coupling finite and boundary element methods in EEG Emmanuel Olivi1, Maureen Clerc1 and Theodore Papadopoulo1  

E-Print Network [OSTI]

in the patient head. Yet, the skull anisotropy happens to be highly anisotropic, and must then be modeled.e. for the brain and the scalp). A domain decomposition (DD) framework allows to split the global system. This work presents such a coupling formulation of a 3-DD method solving iteratively a BEM for the brain

Boyer, Edmond

107

NORTHWESTERN UNIVERSITY Finite Element Analysis of TDR Cable-Grout-Soil Mass  

E-Print Network [OSTI]

NORTHWESTERN UNIVERSITY Finite Element Analysis of TDR Cable-Grout-Soil Mass Interaction During Cable Shear Test.................................................................................................................... 9 Cable Types

108

Solving multidimensional reactive flow problems with adaptive finite elements  

E-Print Network [OSTI]

developments in the design and implementation of finite el- ement methods for the compressible Navier. Braack and T. Richter enthalpy, k its molar production rate, and Fk its mass diffusion flux not the most accurate diffusion model. For hydrogen flames, for instance, multicomponent diffusion models

Richter, Thomas

109

Analysis of anelastic flow and numerical treatment via finite elements  

SciTech Connect (OSTI)

In this report, we reconsider the various approximations made to the full equations of motion and energy transport for treating low-speed flows with significant temperature induced property variations. This entails assessment of the development of so-called anelastic for low-Mach number flows outside the range of validity of the Boussinesq equations. An integral part of this assessment is the development of a finite element-based numerical scheme for obtaining approximate numerical solutions to this class of problems. Several formulations were attempted and are compared.

Martinez, M.J.

1994-05-01T23:59:59.000Z

110

Programing the Finite Element Method with Matlab  

E-Print Network [OSTI]

Oct 3, 2002 ... font d denotes a vector or matrix which is of dimension of the ... following Matlab code which sets the row and column of a matrix A to zero.

2002-10-03T23:59:59.000Z

111

AN ADAPTIVE FINITE ELEMENT METHOD FOR THE ...  

E-Print Network [OSTI]

(R2) with Im ? ? 0 and Re ? > 0 whenever Im ? = 0. First, the problem .... tively refining mesh compared with by uniformly refining mesh. Thus, the present.

2014-05-20T23:59:59.000Z

112

PARTIALLY PENALIZED IMMERSED FINITE ELEMENT METHODS ...  

E-Print Network [OSTI]

v+(x, y) = c+. 1 + c+. 2 x + c+. 3 y, if (x, y) ? K+, which satisfies the following jump conditions [38]: v?(D) = v+(D), v?(E) = v+(E), ??. ?v?. ?nDE. = ?+ ?v+. ?nDE.

2014-03-14T23:59:59.000Z

113

Control-volume mixed finite element methods  

E-Print Network [OSTI]

Z. Cai a, J.E. Jones b, S.F. McCormick c and T.F. Russell d a Center for ...... (59). The Darcy equations for “vertical” faces normal to x-fluxes and y-fluxes would be.

1998-01-23T23:59:59.000Z

114

On the stability of bubble functions and a stabilized mixed finite element formulation for the Stokes problem  

E-Print Network [OSTI]

In this paper we investigate the relationship between stabilized and enriched finite element formulations for the Stokes problem. We also present a new stabilized mixed formulation for which the stability parameter is derived purely by the method of weighted residuals. This new formulation allows equal order interpolation for the velocity and pressure fields. Finally, we show by counterexample that a direct equivalence between subgrid-based stabilized finite element methods and Galerkin methods enriched by bubble functions cannot be constructed for quadrilateral and hexahedral elements using standard bubble functions.

Turner, D Z; Hjelmstad, K D

2008-01-01T23:59:59.000Z

115

A Finite Element Model for Simulation of Carbon Dioxide Sequestration  

SciTech Connect (OSTI)

We present a hydro-mechanical model, followed by stress, deformation, and shear-slip failure analysis for geological sequestration of carbon dioxide (CO2). The model considers the poroelastic effects by taking into account of the two-way coupling between the geomechanical response and the fluid flow process. Analytical solutions for pressure and deformation fields were derived for a typical geological sequestration scenario in our previous work. A finite element approach is introduced here for numerically solving the hydro-mechanical model with arbitrary boundary conditions. The numerical approach was built on an open-source finite element code Elmer, and results were compared to the analytical solutions. The shear-slip failure analysis was presented based on the numerical results, where the potential failure zone is identified. Information is relevant to the prediction of the maximum sustainable injection rate or pressure. The effects of caprock permeability on the fluid pressure, deformation, stress, and the shear-slip failure zone were also quantitatively studied. It was shown that a larger permeability in caprock and base rock leads to a larger uplift but a smaller shear-slip failure zone.

Bao, Jie; Xu, Zhijie; Fang, Yilin

2013-11-02T23:59:59.000Z

116

THE FINITE GROUPS WITH NO REAL p-ELEMENTS SILVIO DOLFI, GUNTER MALLE, AND GABRIEL NAVARRO  

E-Print Network [OSTI]

THE FINITE GROUPS WITH NO REAL p-ELEMENTS SILVIO DOLFI, GUNTER MALLE, AND GABRIEL NAVARRO Abstract/Generalitat Valenciana. 1 #12;2 SILVIO DOLFI, GUNTER MALLE, AND GABRIEL NAVARRO Theorem D. Let G be a finite group

Malle, Gunter

117

The Uranium Processing Facility Finite Element Meshing Discussion  

Broader source: Energy.gov (indexed) [DOE]

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

118

FINITE ELEMENT ANALYSIS OF BULK TRITIUM SHIPPING PACKAGE  

SciTech Connect (OSTI)

The Bulk Tritium Shipping Package was designed by Savannah River National Laboratory. This package will be used to transport tritium. As part of the requirements for certification, the package must be shown to meet the scenarios of the Hypothetical Accident Conditions (HAC) defined in Code of Federal Regulations Title 10 Part 71 (10CFR71). The conditions include a sequential 30-foot drop event, 30-foot dynamic crush event, and a 40-inch puncture event. Finite Element analyses were performed to support and expand upon prototype testing. Cases similar to the tests were evaluated. Additional temperatures and orientations were also examined to determine their impact on the results. The peak stress on the package was shown to be acceptable. In addition, the strain on the outer drum as well as the inner containment boundary was shown to be acceptable. In conjunction with the prototype tests, the package was shown to meet its confinement requirements.

Jordan, J.

2010-06-02T23:59:59.000Z

119

Spring-supported thrust bearings used in hydroelectric generators: Finite element analysis of pad deflection  

Science Journals Connector (OSTI)

An iterative solution technique has been developed for fluid film lubrication of large spring-supported thrust bearings subject to hydrodynamic and hydrostatic lubrication using finite element analysis for pad deflection. Oil film pressures are obtained using a control volume formulation of the Reynolds equation while pad deflections are determined with a commercial finite element analysis package. Low rotor speeds are specified so that isothermal conditions prevail. A computer program links these two numerical methods to implement a solution procedure that consists of iterative loops for applied load, input flow rate, and pad deflection. Illustrative solutions have been obtained showing the influence of spring stiffness, lubricant viscosity, load, and location of the hydrostatic supply pocket.

Ms.A.L. Brown; Dr.J.B. Medley; Mr.J.H. Ferguson

2001-01-01T23:59:59.000Z

120

TESLA FEL Report 200602 Finite Element Analyses for RF Photoinjector Gun Cavities  

E-Print Network [OSTI]

TESLA FEL Report 200602 Finite Element Analyses for RF Photoinjector Gun ..............................................................................................................................................................19 3.1. DESY GUN 2..................................................................................................................................................19 3.2. DESY GUN 4

Note: This page contains sample records for the topic "finite element method" 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

An h-Adaptive Finite-Element Technique for Constructing 3D Wind Fields  

Science Journals Connector (OSTI)

An h-adaptive, mass-consistent finite-element model (FEM) has been developed for constructing 3D wind fields over irregular terrain utilizing sparse meteorological tower data. The element size in the computational domain is dynamically controlled ...

Darrell W. Pepper; Xiuling Wang

2009-03-01T23:59:59.000Z

122

Solar Electric Generating System II finite element analysis  

SciTech Connect (OSTI)

On June 2, 1992, Landers` earthquake struck the Solar Electric Generating System II, located in Daggett, California. The 30 megawatt power station, operated by the Daggett Leasing Corporation (DLC), suffered substantial damage due to structural failures in the solar farm. These failures consisted of the separation of sliding joints supporting a distribution of parabolic glass mirrors. At separation, the mirrors fell to the ground and broke. It was the desire of the DLC and the Solar Thermal Design Assistance Center (STDAC) of Sandia National Laboratories (SNL) and to redesign these joints so that, in the event of future quakes, costly breakage will be avoided. To accomplish this task, drawings of collector components were developed by the STDAC, from which a detailed finite element computer model of a solar collector was produced. This nonlinear dynamic model, which consisted of over 8,560 degrees of freedom, underwent model reduction to form a low order nonlinear dynamic model containing only 40 degrees of freedom. This model was then used as a design tool to estimate joint dynamics. Using this design tool, joint configurations were modified, and an acceptable joint redesign determined. The results of this analysis showed that the implementation of metal stops welded to support shafts for the purpose of preventing joint separation is a suitable joint redesign. Moreover, it was found that, for quakes of Landers` magnitude, mirror breakage due to enhanced vibration in the trough assembly is unlikely.

Dohner, J.L.; Anderson, J.R.

1994-04-01T23:59:59.000Z

123

Wear 258 (2005) 17871793 Finite element analysis and experiments of metal/metal  

E-Print Network [OSTI]

of this simulation. © 2004 Published by Elsevier B.V. Keywords: Wear modeling; Finite element analysis 1 Published by Elsevier B.V. doi:10.1016/j.wear.2004.12.014 #12;1788 N.H. Kim et al. / Wear 258 (2005) 1787Wear 258 (2005) 1787­1793 Finite element analysis and experiments of metal/metal wear

Sawyer, Wallace

124

Finite element simulations of hydrodynamic trapping in microfluidic particle-trap array systems  

E-Print Network [OSTI]

Finite element simulations of hydrodynamic trapping in microfluidic particle- trap array systems;Finite element simulations of hydrodynamic trapping in microfluidic particle-trap array systems Xiaoxiao) simulation is a powerful tool in the design and implementation of microfluidic systems, especially

Nehorai, Arye

125

On Smoothing Surfaces in Voxel Based Finite Element Analysis of Trabecular Bone  

E-Print Network [OSTI]

-)finite element analysis based on three-dimen- sional computed tomography (CT) data of human bone takes place finite element (FE) analysis. The approach based on the FE analysis leads to linear systems of equations analysis the computational domain is composed of a multitude of tiny cubes, so-called voxels

Frey, Pascal

126

Finite element solutions of heat transfer in molten polymer flow in tubes with viscous dissipation  

E-Print Network [OSTI]

Finite element solutions of heat transfer in molten polymer flow in tubes with viscous dissipation the results of finite element analysis of a heat transfer problem of flowing polymer melts in a tube­Nusselt problem 1. Introduction Heat transfer to incompressible viscous non-Newto- nian fluids is a problem

Wei, Dongming

127

Measurement and finite element analysis of temperature distribution in arc welding process  

Science Journals Connector (OSTI)

This presentation describes both the experimental measurement and finite element analysis used to study the temperature distribution during a metal inert gas (MIG) welding process, including the cooling down period. Welding was carried out on ... Keywords: FEA, MIG welding, arc welding, cracking, finite element analysis, metal inert gas welding, residual stress, simulation, temperature distribution, weldment temperature

C. K. Lee; J. Candy; C. P. H. Tan

2004-12-01T23:59:59.000Z

128

Finite Element Stent Design P. Mortier, M. De Beule, B. Verhegghe and P. Verdonck  

E-Print Network [OSTI]

of Drug-Eluting Stents (DES) was an enormous step forward in the treatment of narrowed arteries. Compared distribution. Numerical models (e.g. finite element models) provide a suitable tool to study and to improve stainless steel · Trifolded RAPTORTM balloon (nominal diameter 3 mm; Cordis) · Finite element code: ABAQUS

Gent, Universiteit

129

Finite Element Analysis of TDR Cable-Grout-Soil Mass Interaction During Localized Shearing  

E-Print Network [OSTI]

1 Finite Element Analysis of TDR Cable-Grout-Soil Mass Interaction During Localized Shearing By J and laboratory measurement of Time Domain Reflectometry (TDR) cable-grout response to analyze the interaction between the cable, grout, and surrounding soil mass during localized shearing. Finite element (FE) model

130

Finite element meshing approached as a global minimization process  

SciTech Connect (OSTI)

The ability to generate a suitable finite element mesh in an automatic fashion is becoming the key to being able to automate the entire engineering analysis process. However, placing an all-hexahedron mesh in a general three-dimensional body continues to be an elusive goal. The approach investigated in this research is fundamentally different from any other that is known of by the authors. A physical analogy viewpoint is used to formulate the actual meshing problem which constructs a global mathematical description of the problem. The analogy used was that of minimizing the electrical potential of a system charged particles within a charged domain. The particles in the presented analogy represent duals to mesh elements (i.e., quads or hexes). Particle movement is governed by a mathematical functional which accounts for inter-particles repulsive, attractive and alignment forces. This functional is minimized to find the optimal location and orientation of each particle. After the particles are connected a mesh can be easily resolved. The mathematical description for this problem is as easy to formulate in three-dimensions as it is in two- or one-dimensions. The meshing algorithm was developed within CoMeT. It can solve the two-dimensional meshing problem for convex and concave geometries in a purely automated fashion. Investigation of the robustness of the technique has shown a success rate of approximately 99% for the two-dimensional geometries tested. Run times to mesh a 100 element complex geometry were typically in the 10 minute range. Efficiency of the technique is still an issue that needs to be addressed. Performance is an issue that is critical for most engineers generating meshes. It was not for this project. The primary focus of this work was to investigate and evaluate a meshing algorithm/philosophy with efficiency issues being secondary. The algorithm was also extended to mesh three-dimensional geometries. Unfortunately, only simple geometries were tested before this project ended. The primary complexity in the extension was in the connectivity problem formulation. Defining all of the interparticle interactions that occur in three-dimensions and expressing them in mathematical relationships is very difficult.

WITKOWSKI,WALTER R.; JUNG,JOSEPH; DOHRMANN,CLARK R.; LEUNG,VITUS J.

2000-03-01T23:59:59.000Z

131

1100 IEEE TRANSACTIONS ON BIOMEDICAL ENGINEERING, VOL. 50, NO. 9, SEPTEMBER 2003 Finite-Element Time-Domain Algorithms for  

E-Print Network [OSTI]

frequencies in the context of finite-element time-domain (FETD) numerical solutions of electric potential. The new algorithms, which permit treatment of multiple-pole dielectric relaxations, are based on the auxiliary differential equation method and are unconditionally stable. We validate the algorithms

132

Finite-element/progressive-lattice-sampling response surface methodology and application to benchmark probability quantification problems  

SciTech Connect (OSTI)

Optimal response surface construction is being investigated as part of Sandia discretionary (LDRD) research into Analytic Nondeterministic Methods. The goal is to achieve an adequate representation of system behavior over the relevant parameter space of a problem with a minimum of computational and user effort. This is important in global optimization and in estimation of system probabilistic response, which are both made more viable by replacing large complex computer models with fast-running accurate and noiseless approximations. A Finite Element/Lattice Sampling (FE/LS) methodology for constructing progressively refined finite element response surfaces that reuse previous generations of samples is described here. Similar finite element implementations can be extended to N-dimensional problems and/or random fields and applied to other types of structured sampling paradigms, such as classical experimental design and Gauss, Lobatto, and Patterson sampling. Here the FE/LS model is applied in a ``decoupled`` Monte Carlo analysis of two sets of probability quantification test problems. The analytic test problems, spanning a large range of probabilities and very demanding failure region geometries, constitute a good testbed for comparing the performance of various nondeterministic analysis methods. In results here, FE/LS decoupled Monte Carlo analysis required orders of magnitude less computer time than direct Monte Carlo analysis, with no appreciable loss of accuracy. Thus, when arriving at probabilities or distributions by Monte Carlo, it appears to be more efficient to expend computer-model function evaluations on building a FE/LS response surface than to expend them in direct Monte Carlo sampling.

Romero, V.J.; Bankston, S.D.

1998-03-01T23:59:59.000Z

133

Seismic wave propagation in coal seams: finite element modelling and field tests  

Science Journals Connector (OSTI)

In-seam seismic (ISS) refers to methods which utilise artificially generated channel waves trapped in coal seam to locate geologic disturbances and mine voids. It is one of the basic geophysical methods for underground survey. The advantage of ISS is that seismic energy is better preserved in coal seams and seismic waves can travel and be detected over much larger distances in comparison with body waves which radiate three-dimensionally. It is also convenient and reasonable to set up a two-dimensional model to study the wave propagation characteristics. Using a commercial finite element method (FEM) modelling software, both transmission and reflection tests were simulated. Field experiments of the ISS technology have been carried out at underground coal mines. The results demonstrated that two-dimensional FEM modelling appears to be a satisfactory approach for ISS simulation, and if used properly, ISS technology can successfully detect mine voids and geologic discontinuities.

Hongliang Wang; Maochen Ge

2014-01-01T23:59:59.000Z

134

Initial Testing of a Two-Dimensional Finite Element Model for Floodplain Inundation  

Science Journals Connector (OSTI)

8 January 1994 research-article Initial Testing of a Two-Dimensional Finite Element Model for Floodplain...expectations and the need for improved data acquisition for model testing is highlighted. On the basis of these numerical experiments...

1994-01-01T23:59:59.000Z

135

Finite element simulation and parameter optimization of a flexible tactile pressure sensor array  

E-Print Network [OSTI]

A finite element model was developed to optimize design of a flexible tactile sensor. The sensor consists of layers of thin-film copper and PDMS, and the model can be used to determine the effects on sensor sensitivity and ...

Lee, Shira M. (Shira Miriam)

2005-01-01T23:59:59.000Z

136

A FINITE ELEMENT MODEL FOR THE TIME-DEPENDENT JOULE HEATING PROBLEM*  

E-Print Network [OSTI]

.3) 0 system models the electric heating* *ial differential equation describing the electric heating of a conducting body. We prove err* *or A FINITE ELEMENT MODEL FOR THE TIME-DEPENDENT JOULE HEATING PROBLEM

Larsson, Stig

137

TEA - a linear frequency domain finite element model for tidal embayment analysis  

E-Print Network [OSTI]

A frequency domain (harmonic) finite element model is developed for the numerical prediction of depth average circulation within small embayments. Such embayments are often characterized by irregular boundaries and bottom ...

Westerink, Joannes J.

1984-01-01T23:59:59.000Z

138

Finite element analysis of flows in secondary settling tanks D. Kleine 1 B. D. Reddy 2  

E-Print Network [OSTI]

Finite element analysis of flows in secondary settling tanks D. Kleine 1 B. D. Reddy 2 December 7, 2003 Abstract The equations governing unsteady flows in secondary settling tanks, a component settling tanks, and against results obtained from a finite difference code based on an idealized one

Reddy, Batmanathan Dayanand "Daya"

139

A finite element viscous flow analysis in a radial turbine scroll  

E-Print Network [OSTI]

1987 Major Subject: Mechanical Engineering A FINITE ELEMENT VISCOUS FLOW ANALYSIS IN A RADIAL TURBINE SCROLL A Thesis by DONALD LEE HILL JR. Approved as to style snd content by: Dr. Erian A. Baskharone (Chairman of Conunittee) Dr. Alan B azzolo...A FINITE ELEMENT VISCOUS FLOW ANALYSIS IN A RADIAL TURBINE SCROLL A Thesis DONALD LEE HILL JR. Submitted to the Graduate College. of Texas ASM University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE December...

Hill, Donald Lee

1987-01-01T23:59:59.000Z

140

Finite element analysis of conjugate heat transfer in axisymmetric pipe flows  

E-Print Network [OSTI]

FINITE ELEMENT ANALYSIS OF CONJUGATE HEAT TRANSFER IN AXISYMMETRIC PIPE FLOWS A Thesis by ROBERT MILLER FITHEN Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MA STER... OF S CI EN CE August 1987 Major Subject: Mechanical Engineering FINITE ELEMENT ANALYSIS OF CONJUGATE HEAT TRANSFER IN AXISYMMETRIC PIPE FLOWS A Thesis by ROBERT MILLER FITHEN Approved ss to style and content by: N. K. Anand (Chairman of Committee...

Fithen, Robert Miller

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Two dimensional finite element analysis of homogenization and failure in plain weave textile composites  

E-Print Network [OSTI]

TWO DIMENSIONAL FINITE ELEMENT ANALYSIS OF HOMOGENIZATION AND FAILURE IN PLAIN WEAVE TEXTILE COMPOSITES A Thesis by VEERARAGHAVA GOPAL KONDAGUNTA Submitted to the Office of Graduate Studies of Texas ARM University In partial fulffllment... of the requirements for the degree of MASTER OF SCIENCE August 1993 Major Subject: Aerospace Engineering TWO DIMENSIONAL FINITE ELEMENT ANALYSIS OF HOMOGENIZATION AND FAILURE IN PLAIN WEAVE TEXTILE COMPOSITES A Thesis by VEERARAGHAVA GOPAL KONDAGUNTA...

Kondagunta, Veeraraghava Gopal

2012-06-07T23:59:59.000Z

142

Evaluation of new techniques for two dimensional finite element analysis of woven composites  

E-Print Network [OSTI]

EVALUATION OF NEW TECHNIQUES FOR TWO DIMENSIONAL FINITE ELEMENT ANALYSIS OF WOVEN COMPOSITES A Thesis by SITARAM CHOWDARY GUNDAPANENI Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirement for the degree of MASTER OF SCIENCE DECEMBER 1992 Major Subject: Aerospace Engineering EVALUATION OF NEW TECHNIQUES FOR TWO DIMENSIONAL FINITE ELEMENT ANALYSIS OF WOVEN COMPOSITES A Thesis by SITARAM CHOWDARY GUNDAPANENI Approved...

Gundapaneni, Sitaram Chowdary

2012-06-07T23:59:59.000Z

143

A shear deformable, doubly curved finite element for the analysis of laminated composite structures  

E-Print Network [OSTI]

A SHL'AR DEFORMABLE, DOUBLY CURVED FINITE ELEMENT FOR THE ANALYSIS OF LAMINATED COMPOSITE STRUCTURES A Thesis by JOSEPH PATRICK FUEHNE Submitted to the Graduate College of Texas AE-M University in partial fulfiHment of the requirement... for the degree of MASTER OF SCIENCE May 1988 Major Subject: Mechanical Engineering A SHEAR DEFORMABLE, DOUBLY CURVED FINITE ELEMENT FOR THE ANALYSIS OF LAMINATED COMPOSITE STRUCTURES A Thesis by JOSEPH PATRICK FUEHNE Approved as to style and content by...

Fuehne, Joseph Patrick

2012-06-07T23:59:59.000Z

144

A three dimensional finite element code for the analysis of damage in helically wound composite cylinders  

E-Print Network [OSTI]

A THREE DIMENSIONAL FINITE ELEMENT CODE FOR THE ANALYSIS OF DAMAGE IN HELICALLY WOUND COMPOSITE CYLINDERS A Thesis MARVIiN AiNTHONY ZOCHER Submitted to the Office of Graduate Studies of Texas Ag:M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 1990 Major Subject; Aerospace Engineering A THREE DIMENSIONAL FINITE ELEMENT CODE FOR THE ANALYSIS OF DAMAGE IN HELICALLY WOUND COMPOSITE CYLINDERS A Thesis by i%1ARVIN ANTHONY ZOCHER Approved...

Zocher, Marvin Anthony

2012-06-07T23:59:59.000Z

145

Constitutive model effects on finite element modeling of elastomer behavior in radial interference seal configurations  

E-Print Network [OSTI]

CONSTITUTIVE MODEL EFFECTS ON FINITE ELEMENT MODELING OF ELASTOMER BEHAVIOR IN RADIAL INTERFERENCE SEAL CONFIGURATIONS A Thesis by JASON R. JACKSON Subnutted to the Office of Graduate Studies of Texas A&M University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE August 1996 Major Subject: Mechanical Engineering CONSTITUTIVE MODEL EFFECTS ON FINITE ELEMENT MODELING OF ELASTOMER BEHAVIOR IN RADIAL INTERFERENCE SEAL CONFIGURATIONS A Thesis by JASON R. JACKSON...

Jackson, Jason R.

1996-01-01T23:59:59.000Z

146

Finite element modeling of heat and mass transport in aquifers  

E-Print Network [OSTI]

of the grid test problem transient temperature distribution using upstream weighting to the solution of Avdonin (1964)(linear elements). 60 Comparison of the radial test problem transient temperature profile using upstream weighting to the solution... of Avdonin (1964)(linear elements) . . 61 12 13 Comparison of the grid problem transient temperature profile using mass lumping to the solution of Avdonin (1964). Comparison of the grid problem temperature progression using mass lumping to the solution...

Grubaugh, Elston Kent

1980-01-01T23:59:59.000Z

147

Non-periodic finite-element formulation of KohnSham density functional theory  

E-Print Network [OSTI]

Non-periodic finite-element formulation of Kohn­Sham density functional theory Phanish-element formulation for Kohn­Sham density functional theory (KS-DFT). We transform the original variational problem, dislocations and crack tips using density functional theory (DFT) at reasonable computational cost by retaining

Ortiz, Michael

148

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

SciTech Connect (OSTI)

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

149

A piecewise linear finite element discretization of the diffusion equation  

E-Print Network [OSTI]

it discretizes the diffusion equation on an arbitrary polyhedral mesh. We implemented our method in the KULL software package being developed at Lawrence Livermore National Laboratory. This code previously utilized Palmer's method as its diffusion solver, which...

Bailey, Teresa S

2006-10-30T23:59:59.000Z

150

Stress intensity Factors calculated generally by the Finite Element Technique  

Science Journals Connector (OSTI)

... accuracy of the method. Brown, W. F., and Srawley, J. E., ASTM STP 410 (American Society for Testing and Materials, Philadelphia, 1966).

J. R. DIXON; L. P. POOK

1969-10-11T23:59:59.000Z

151

electroseismic monitoring of co2 sequestration: a finite element ...  

E-Print Network [OSTI]

The injection of large amounts of man-produced CO2 in depleted oil wells below ..... [7] SANTOS, J. E., Global and domain-decomposed mixed methods for the ...

Fabio Zyserman

152

Finite element plate formulation including transverse shear effects for representing composite shell structures  

E-Print Network [OSTI]

For Representing Composite Shell Structures. (May 1987) Jsmil M. Hamdallah, B. S. , University of Toledo Chairman of Advisory Committee: Dr. John J. Engblom A finite element formulation for the analysis of thin to moderately thick lam- inated composite shell... in an analysis if delamination is to be avoided. The results obtained in this research confirm the potential use of the element presented as an accurate and eflicient tool in the analysis of thin to moderately thick laminated shell structures. To my parents...

Hamdallah, Jamil M.

2012-06-07T23:59:59.000Z

153

CALIBRATION OFTHE FINITE ELEMENT MODEL OFA TWELVE-SPAN PRESTRESSED CONCRETE BRIDGE USING  

E-Print Network [OSTI]

CALIBRATION OFTHE FINITE ELEMENT MODEL OFA TWELVE-SPAN PRESTRESSED CONCRETE BRIDGE USING AMBIENT health monitoring system was designed and installed in the bridge. As a critical part in the SHM process the implementation of the FE model calibration using ambient vibration data. The initial model of the bridge

Paris-Sud XI, Université de

154

Coupled axisymmetric finite element model of a hydraulically amplified magnetostrictive actuator for active powertrain mounts  

Science Journals Connector (OSTI)

A coupled axisymmetric finite element model is formulated to describe the dynamic performance of a hydraulically amplified magnetostrictive actuator for active powertrain mounts. The formulation is based on the weak form representations of Maxwell's ... Keywords: Active powertrain mount, Actuator, Axisymmetric model, Magnetostriction, Terfenol-D

Suryarghya Chakrabarti; Marcelo J. Dapino

2012-11-01T23:59:59.000Z

155

Finite element-based analysis of shunted piezoelectric structures for vibration damping  

Science Journals Connector (OSTI)

Piezoelectric patches shunted with passive electrical networks can be attached to a host structure for reduction of structural vibrations. This approach is frequently called ''shunted piezo damping'' and has the advantage of guaranteed stability and ... Keywords: Finite element analysis, Passive electrical network, Piezoelectric structure, Vibration damping

Jens Becker; Oliver Fein; Matthias Maess; Lothar Gaul

2006-12-01T23:59:59.000Z

156

How does trench coupling lead to mountain building in the Subandes? A viscoelastoplastic finite element model  

E-Print Network [OSTI]

How does trench coupling lead to mountain building in the Subandes? A viscoelastoplastic finite element model Gang Luo1 and Mian Liu1 Received 10 June 2008; revised 3 December 2008; accepted 2 February cause of the Andean mountain building. The present-day crustal shortening in the Andes is clear from

Liu, Mian

157

A Finite Element Model for Ice Ball Evolution in a Multi-probe Cryosurgery  

E-Print Network [OSTI]

to intracellular ice injury for fast cooling rates, and solution effects injury for slow cooling rates. BasicallyA Finite Element Model for Ice Ball Evolution in a Multi-probe Cryosurgery RICHARD WANa, *, ZHIHONG October 2002; In final form 8 May 2003) The ice formation in a water body is examined for the computation

Wan, Richard G.

158

Thermo-elasto-plastic finite element analysis of quasi-state processes in Eulerian reference  

E-Print Network [OSTI]

Thermo-elasto-plastic finite element analysis of quasi-state processes in Eulerian reference frames ­ Incremental scheme ­ Fine mesh along entire heat source path ­ Lengthy computer runs · Elasto-Plasticity at times ti and ti-1, respectively. Penn State University 5 #12;Elasto-Plasticity Equilibrium: r(r, t) + b

Michaleris, Panagiotis

159

Local Flaps: A Real-Time Finite Element Based Solution to the Plastic Surgery  

E-Print Network [OSTI]

Local Flaps: A Real-Time Finite Element Based Solution to the Plastic Surgery Defect Puzzle fundamental challenges in plastic surgery is the alter- ation of the geometry and topology of the skin for the patient after the procedure is completed. The plastic surgeon must look at the defect created

Liblit, Ben

160

Finite Element Analysis of a Composite Semi-Span Test Article With and Without Discrete Damage  

Science Journals Connector (OSTI)

AS&M, Inc. performed finite element analysis, with and without discrete damage, of a composite semi-span test article that represents the Boeing 220-passenger transport aircraft composite semi-span test article. A NASTRAN bulk data file and drawings ...

Lovejoy Andrew E.

2000-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

On a tensor-based finite element model for the analysis of shell structures  

E-Print Network [OSTI]

In the present study, we propose a computational model for the linear and nonlinear analysis of shell structures. We consider a tensor-based finite element formulation which describes the mathematical shell model in a natural and simple way by using...

Arciniega Aleman, Roman Augusto

2006-04-12T23:59:59.000Z

162

A Finite-Element Model for Simulation of Carbon Dioxide Sequestration  

SciTech Connect (OSTI)

Herein, we present a coupled thermal-hydro-mechanical model for geological sequestration of carbon dioxide followed by the stress, deformation, and shear-slip failure analysis. This fully coupled model considers the geomechanical response, fluid flow, and thermal transport relevant to geological sequestration. Both analytical solutions and numerical approach via finite element model are introduced for solving the thermal-hydro-mechanical model. Analytical solutions for pressure, temperature, deformation, and stress field were obtained for a simplified typical geological sequestration scenario. The finite element model is more general and can be used for arbitrary geometry. It was built on an open-source finite element code, Elmer, and was designed to simulate the entire period of CO2 injection (up to decades) both stably and accurately—even for large time steps. The shear-slip failure analysis was implemented based on the numerical results from the finite element model. The analysis reveals the potential failure zone caused by the fluid injection and thermal effect. From the simulation results, the thermal effect is shown to enhance well injectivity, especially at the early time of the injection. However, it also causes some side effects, such as the appearance of a small failure zone in the caprock. The coupled thermal-hydro-mechanical model improves prediction of displacement, stress distribution, and potential failure zone compared to the model that neglects non-isothermal effects, especially in an area with high geothermal gradient.

Bao, Jie; Xu, Zhijie; Fang, Yilin

2014-09-01T23:59:59.000Z

163

Finite element simulation of three-dimensional free-surface flow problems  

E-Print Network [OSTI]

surface. The technique is illustrated through an implementation for surface-tension-dominated viscous understanding the evolution and stability of free surfaces provides one of the major incentivesFinite element simulation of three-dimensional free-surface flow problems M.A. Walkley1 £, P

Jimack, Peter

164

Stabilized finite element formulations for liquid membranes and their application to droplet contact  

E-Print Network [OSTI]

and liquid coats. The mechanics of liquid membranes is governed by the surface tension of liquids, whichStabilized finite element formulations for liquid membranes and their application to droplet of the curvilinear coordinate system that is used for the surface description of the membrane. Particular emphasize

165

A Mixed Finite Element Approximation for Compressible Flow of Contamination from Nuclear  

E-Print Network [OSTI]

A Mixed Finite Element Approximation for Compressible Flow of Contamination from Nuclear Waste in Porous Media S. H. CHOU AND Q. LI Abstract A compressible nuclear waste disposal contamination in porous the effects of molecular diffusion and dispersion. Secondly, the ``complete compressibility'' case

Chou, So-Hsiang

166

Minimizing EIT image artefacts from mesh variability in Finite Element Models  

E-Print Network [OSTI]

artefacts which occur in electrical impedance tomography (EIT) images due to limitations in finite element R B Lionheart2 1 Systems and Computer Engineering, Carleton University, Ottawa, Canada 2 School of Mathematics, University of Manchester, UK Abstract. Electrical Impedance Tomography solves an inverse problem

Adler, Andy

167

Numerical Simulation of Detonation Initiation by the Space-Time Conservation Element and Solution Element Method.  

E-Print Network [OSTI]

??This dissertation is focused on the numerical simulation of the detonation initiation process. The space-time Conservation Element and Solution Element (CESE) method, a novel numerical… (more)

Wang, Bao

2010-01-01T23:59:59.000Z

168

An Object-Oriented Finite Element Framework for Multiphysics Phase Field Simulations  

SciTech Connect (OSTI)

The phase field approach is a powerful and popular method for modeling microstructure evolution. In this work, advanced numerical tools are used to create a phase field framework that facilitates rapid model development. This framework, called MARMOT, is based on Idaho National Laboratory's finite element Multiphysics Object-Oriented Simulation Environment. In MARMOT, the system of phase field partial differential equations (PDEs) are solved simultaneously with PDEs describing additional physics, such as solid mechanics and heat conduction, using the Jacobian-Free Newton Krylov Method. An object-oriented architecture is created by taking advantage of commonalities in phase fields models to facilitate development of new models with very little written code. In addition, MARMOT provides access to mesh and time step adaptivity, reducing the cost for performing simulations with large disparities in both spatial and temporal scales. In this work, phase separation simulations are used to show the numerical performance of MARMOT. Deformation-induced grain growth and void growth simulations are included to demonstrate the muliphysics capability.

Michael R Tonks; Derek R Gaston; Paul C Millett; David Andrs; Paul Talbot

2012-01-01T23:59:59.000Z

169

Development and applications of two finite element groundwater flow and contaminant transport models: FEWA and FEMA  

SciTech Connect (OSTI)

This paper presents the construction, verification, and application of two groundwater flow and contaminant transport models: A Finite Element Model of Water Flow through Aquifers (FEWA) and A Finite Element Model of Material Transport through Aquifers (FEMA). The construction is based on the finite element approximation of partial differential equations of groundwater flow (FEWA) and of solute movement (FEMA). The particular features of FEWA and FEMA are their versatility and flexibility for dealing with nearly all vertically integrated two-dimensional problems. The models were verified against both analytical solutions and widely used US Geological Survey finite difference approximations. They were then applied for calibration and validation, using data obtained in experiments at the Engineering Test Facility at Oak Ridge National Laboratory. Results indicated that the models are valid for this specific site. To demonstrate the versatility anf flexibility of the models, they were applied to two hypothetical, but realistic, complex problems and three field sites across the United States. In these applications the models yielded good agreement with the field data for all three sites. Finally, the predictive capabilities of the models were demonstrated using data obtained at the Hialeah Preston site in Florida. This case illustrates the capability of FEWA and FEMA as predictive tools and their usefulness in the management of groundwater flow and contaminant transport. 25 refs.

Yeh, G.T.; Wong, K.V.; Craig, P.M.; Davis, E.C.

1985-01-01T23:59:59.000Z

170

Finite element analysis of bending in a threaded connector for a 5 1/2-in. Marine riser  

SciTech Connect (OSTI)

This paper describes the development of a new finite element modelling technique for performing nonlinear bending analysis of tubulars and its application to a threaded connector for a 5-1/2 inch production tubing marine riser. A finite element technique has been developed for analyzing bending loads applied to an axisymmetric geometry. The method uses a Fourier series solution. The first two terms of the series are solved simultaneously, allowing nonlinearities to be included since the method does not use superposition, which normally requires linearity. Existing methods of analysis require either a linear elastic assumption, and axisymmetric approximation of bending loads, or a full three dimensional analysis. The new technique includes nonlinearities in mechanical properties, gapping, and friction. It is more accurate than the method where axisymmetric loads are applied so that pipe OD stresses are the same as those that would result from bending. The model is considerably less complicated to use than a three dimensional model and is also considerably less expensive. The method described above is applied to a 5-1/2 inch threaded connector. The connector is analyzed under make-up, tension, pressure, bending, and shear loads. Predictions include average and reversing stresses in the pin and box wall and at stress concentrations. These predictions can be used to evaluate the fatigue life of the connector.

Allen, M.B.; Eichberger, L.C.

1984-05-01T23:59:59.000Z

171

Finite-element modelling of YBCO fault current limiter with temperature dependent  

Science Journals Connector (OSTI)

In this paper, we present a numerical model which takes into account both the thermal and the electromagnetic aspects of the over-critical current regime for high-temperature superconducting (HTS) materials. The electromagnetic and thermal equations have been implemented in finite-element method (FEM) software in order to obtain a novel model for investigating the behaviour of the materials when the current exceeds Ic and the superconductor material goes to the normal state. The thermal dependence of the electrical parameters, such as the critical current density Jc, has been introduced. This model has been used to analyse the behaviour of strip lines of a YBCO/Au fault current limiter (FCL) on a sapphire substrate. Simulations with currents exceeding Ic have been performed, showing that the current limitation phase can be correctly reproduced. Such a model can be used to study the influence of the geometry on the performance of the FCL. It can replace experiments with currents exceeding Ic which may damage or destroy HTS samples and devices.

J Duron; F Grilli; L Antognazza; M Decroux; B Dutoit; Ø Fischer

2007-01-01T23:59:59.000Z

172

Numerical modeling of buoyancy-driven flows in a rotating cylindrical cavity: Comparison of a finite element model with a spectral model  

SciTech Connect (OSTI)

A finite element model is developed for the prediction of the motion of rotating Boussinesq fluid driven by buoyancy. The computations are performed for the axisymmetric regime in an annular cavity for Reynolds number varying from 0 to 2,500. The results are compared with those of an earlier study of this problem using a spectral Tau-Chebyshev method. The good agreement found assesses the finite element model. Finally, a complementary convergence analysis gives the sensitivity of the model to mesh refinement.

Jaeger, M.; Medale, M.; Randriamanpianina, A. [Centre National de la Recherche Scientifique, Marseille (France)

1996-12-01T23:59:59.000Z

173

Resummation Methods at Finite Temperature: The Tadpole Way  

E-Print Network [OSTI]

We examine several resummation methods for computing higher order corrections to the finite temperature effective potential, in the context of a scalar $\\phi^4$ theory. We show by explicit calculation to four loops that dressing the propagator, not the vertex, of the one-loop tadpole correctly counts ``daisy'' and ``super-daisy'' diagrams.

C. Glenn Boyd; David E. Brahm; Stephen D. H. Hsu

1993-04-15T23:59:59.000Z

174

Enhanced finite element analysis using the PATRAN-G pre- and post processor program  

E-Print Network [OSTI]

the layers of a composite inaterial with nodes and orientation General overview diagram of PATRAN-G svsyteni and interfaces Finite element mesh of 36 element plate with nodes labeled Stress contour plot showing the in-plane stress in the x...-direction for layer 1 Stress contour plot showing the in-plane stress in the y-direction for layer 1 Stress contour plot showing the in-plane xy stress for layer 1 Stress contour plot showing the transverse xz stress for layer 9 Stress contour plot...

Murry, Margaret Lois

2012-06-07T23:59:59.000Z

175

Finite element model-simulation-based characterization of a magnetostrictive gyrosensor  

SciTech Connect (OSTI)

This paper analyzes a prototype microgyrosensor that employs the magnetostrictive alloy Galfenol for transduction of Coriolis-induced forces into an electrical output for quantifying a given angular velocity. The magnetic induction distribution in the Galfenol sensor patch depends on its bending shape and magnetoelastic properties and is investigated using a finite element model. Fluctuations in magnetic induction caused by a sinusoidal rotation of the sensor produce an amplitude modulated voltage in a surrounding coil which is simulated and measured.

Marschner, U. [Institute for Semiconductor and Microsystems Technology, Technische Universitaet Dresden, 01062 Dresden (Germany); Graham, F.; Yoo, J.-H.; Flatau, A. B. [Department of Aerospace Engineering, University of Maryland, College Park, Maryland 20742 (United States); Mudivarthi, C. [Department of Materials Science and Engineering, University of Maryland, College Park, Maryland 20742 (United States); Neubert, H. [Institute for Electromechanical and Electronic Design, Technische Universitaet Dresden, 01062 Dresden (Germany)

2010-05-15T23:59:59.000Z

176

Materials Science and Engineering B 117 (2005) 5361 Finite element analysis-based design of a fluid-flow control nano-valve  

E-Print Network [OSTI]

of a fluid-flow control nano-valve M. Grujicica,, G. Caoa, B. Pandurangana, W.N. Royb a Department A finite element method-based procedure is developed for the design of molecularly functionalized nano-size devices. The procedure is aimed at the single-walled carbon nano-tubes (SWCNTs) used in the construction

Grujicic, Mica

177

Finite element simulation of moisture movement and solute transport in a large caisson  

SciTech Connect (OSTI)

The results of the solute transport experiments performed on compacted, crushed Bandelier Tuff in caisson B of the experimental cluster described by DePoorter (1981) are simulated. Both one- and three-dimensional simulations of solute transport have been performed using two selected finite element codes. Results of bromide and iodide tracer experiments conducted during near-steady flow conditions have been analyzed for pulse additions made on December 6, 1984, and followed over a period of up to 60 days. In addition, a pulse addition of nonconservative strontium tracer on September 28, 1984, during questionably steady flow conditions has been analyzed over a period of 240 days. One-dimensional finite element flow and transport simulations were carried out assuming the porous medium to be homogeneous and the injection source uniformly distributed. To evaluate effects of the nonuniform source distribution and also to investigate effects of inhomogeneous porous medium properties, three dimensional finite element analyses of transport were carried out. Implications of the three-dimensional effects for the design and analysis of future tracer studies are discussed.

Huyakorn, P.S.; Jones, B.G.; Parker, J.C.; Wadsworth, T.D.; White, H.O. Jr.

1987-04-01T23:59:59.000Z

178

Three-dimensional finite-element model for simulating water flow in variability saturated porous media  

SciTech Connect (OSTI)

A three-dimensional finite-element model for simulating water flow in variably saturated porous media is presented. The model formulation is general and capable of accommodating complex boundary conditions associated with seepage faces and infiltration or evaporation on the soil surface. Included in this formulation is an improved Picard algorithm designed to cope with severely nonlinear soil moisture relations. The algorithm is formulated for both rectangular and triangular prism elements. The element matrices are evaluated using an influence coefficient technique that avoids costly numerical integration. Spatial discretization of a three-dimensional regions is performed using a vertical slicing approach designed to accommodate complex geometry with irregular boundaries, layering, and/or lateral discontinuities. Matrix solution is achieved using a slice successive overrelaxation scheme that permits a fairly large number of nodal unknowns (on the order of several thousand) to be handled efficiently on small minicomputers. Six examples are presented to verify and demonstrate the utility of the proposed finite-element model. The first four examples concern one- and two-dimensional flow problems used as sample problems to benchmark the code. The remaining examples concern three-dimensions problems. These problems are used to illustrate the performance of the proposed algorithm in three-dimensional situations involving seepage faces and anisotropic soil media.

Huyakorn, P.S.; Springer, E.P.; Guvanasen, V.; Wadsworth, T.D.

1986-12-01T23:59:59.000Z

179

Electrical-Thermal-Structural Coupled Finite Element Model of High Temperature Superconductor for Resistive Type Fault Current Limiters  

Science Journals Connector (OSTI)

A multi-physics finite element model of high-temperature superconductors (HTS) will be presented in this article. The electrical-thermal model is mainly based on Maxwell’s equation and basic heat transfer equa...

J. Sheng; Y. Chen; B. Lin; L. Ying; Z. Jin…

2014-06-01T23:59:59.000Z

180

Operator-adapted finite element wavelets : theory and applications to a posteriori error estimation and adaptive computational modeling  

E-Print Network [OSTI]

We propose a simple and unified approach for a posteriori error estimation and adaptive mesh refinement in finite element analysis using multiresolution signal processing principles. Given a sequence of nested discretizations ...

Sudarshan, Raghunathan, 1978-

2005-01-01T23:59:59.000Z

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


181

Introduction to finite-difference methods for numerical fluid dynamics  

SciTech Connect (OSTI)

This work is intended to be a beginner`s exercise book for the study of basic finite-difference techniques in computational fluid dynamics. It is written for a student level ranging from high-school senior to university senior. Equations are derived from basic principles using algebra. Some discussion of partial-differential equations is included, but knowledge of calculus is not essential. The student is expected, however, to have some familiarity with the FORTRAN computer language, as the syntax of the computer codes themselves is not discussed. Topics examined in this work include: one-dimensional heat flow, one-dimensional compressible fluid flow, two-dimensional compressible fluid flow, and two-dimensional incompressible fluid flow with additions of the equations of heat flow and the {Kappa}-{epsilon} model for turbulence transport. Emphasis is placed on numerical instabilities and methods by which they can be avoided, techniques that can be used to evaluate the accuracy of finite-difference approximations, and the writing of the finite-difference codes themselves. Concepts introduced in this work include: flux and conservation, implicit and explicit methods, Lagrangian and Eulerian methods, shocks and rarefactions, donor-cell and cell-centered advective fluxes, compressible and incompressible fluids, the Boussinesq approximation for heat flow, Cartesian tensor notation, the Boussinesq approximation for the Reynolds stress tensor, and the modeling of transport equations. A glossary is provided which defines these and other terms.

Scannapieco, E.; Harlow, F.H.

1995-09-01T23:59:59.000Z

182

The Extended Finite Element Method for High Gradient Solutions  

E-Print Network [OSTI]

Outline Enrichment functions for high gradient solutions Motivation High gradient inside the domain (Shocks) High gradient at the boundary (boundary layers) Optimal set of enrichment functions Numerical for high gradient solutions Outline Enrichment functions for high gradient solutions Motivation High

183

Coupling of finite element and boundary integral methods for ...  

E-Print Network [OSTI]

Oct 8, 2009 ... sparse, and banded matrix; ½A12? is an Nn ? Ne rectangular and sparse ... ple MATLAB mesh generator distmesh2d by Persson and Strang [38] is ... 2 shows the graphs of the real part and the imaginary part of the field.

"Peijun Li"

2009-11-09T23:59:59.000Z

184

stabilized finite element methods for coupled geomechanics and ...  

E-Print Network [OSTI]

7.23 Reservoir model with two shale layers . .... Water, oil and natural gas are all fluids that exist within the pore spaces and fractures of natural reservoir rocks.

185

Computable Error Bounds in the Finite-Element Method  

Science Journals Connector (OSTI)

......carefully estimating the integrals is applied by Arcangeli & Gout (1976) and Gout (1977); they used the Taylor series remainder and...D. Thesis. Univ. of Zurich. ARCANGELI, R., & GOUT J. L. 1976 Sur revaluation de l'erreur d'interpolation......

REINHARD LEHMANN

1986-07-01T23:59:59.000Z

186

Finite Element Methods for Nonlinear Acoustics in Fluids  

E-Print Network [OSTI]

could include both material and geometric nonlinearities. However ..... easily be made explicit by an appropriate selection of parameters, see.6. Figures 7, 8, and

187

A finite element method for surface diffusion: the parametric case  

E-Print Network [OSTI]

, 3000 Santa Fe, Argentina (pmorin@math.unl.edu.ar). Partially supported by CONICET of Argentina and NSFS S is the Laplace-Beltrami operator and is the elastic energy density of the bulk (t) enclosed by (t

Nochetto, Ricardo H.

188

AMSC 614 -SPRING 08 MATHEMATICS OF THE FINITE ELEMENT METHOD  

E-Print Network [OSTI]

mainly via MATLAB computer projects. Stokes flow over an L-shaped domain: Pressures and meshes for error to graduate level PDE and MATLAB will be useful but not mandatory. This course may be an excellent complement. Evaluation: Homeworks, both theoretical and computational. Basic MATLAB pro- grams will be distributed

O'Leary, Dianne P.

189

The Finite Volume Element Method for Diffusion Equations on ...  

E-Print Network [OSTI]

Dec 6, 2003 ... and, for all E,, c me, that. lfijW)! S 6'02(1 + C”)lZij13/2 [Vail/2 Mullah,-. By Lemma 1, these inequalities imply that. 1 / a... S We + oh (in... + watts).

190

Analysis of complex viscoelastic flows using a finite element method  

E-Print Network [OSTI]

The field of computational fluid mechanics of viscoelastic flows has been well explored in the three decades since its inception. Still, even with the vast amount of work detailed in the literature, much remains to be done ...

Phillips, Scott David, Ph. D. Massachusetts Institute of Technology

2006-01-01T23:59:59.000Z

191

An application of stochastic finite element method in structural reliabiity  

E-Print Network [OSTI]

to buckling. In particular, it is shown that the higher the frequency of fluctuation of the material uncertainties around their mean values, the less is the effect of these uncertainties on the buckling load. To My Mother, Sneh Lata, and Father, Shiv Gopal... education I have received at Texas A&M University. I do not have words to express my appreciation to my sister, Mons, and my parents, Mrs. Sneh Lata and Mr. Shiv Gopal, for their greatest patience, love and sacrifice over the years. Without their moral...

Agrawal, Sanjay

2012-06-07T23:59:59.000Z

192

Discontinuous finite element methods for particle transport problems  

E-Print Network [OSTI]

), wc obtain: ( Ay ]I?. . . , . . . , , , ~, , i ( rA, +Jt +2/, 2J 1 8a13x ( ~1( ( ? ii2, i ? li2 i+I/2, i ? I, '2 ri+I/2, i+Ij2 r ? 112 iili2) 18crdy) ' ( (ri+I, '2, 1-1;2 r +'3'2, i ? I/2 ri+'t'2 I+I/2 2'i+112 I+112 ) 18crhx ( ( i+li2, 1 ? Ii2 r... +1i2 I ? li2 r +'li2 I+li2 r, +I, '2 I+I/2 ) ( i I+I ( ~1 (ri-lj2, i+li2 ri+I/2, 1+Iir ritl/2, i+3i2 3 ? 132, ii3/2) 18crt5y) + ( Ay ( At+I/2, 1+ll2 At+332, 1 ~ I/2 Pi+le'2, 1+3/2 Pi+I/2. i+ti2) 2, , ? 2 3, ? . . . + a , +I I+I ( r+I/2, I+I/2...

Stone, Hiromi

2012-06-07T23:59:59.000Z

193

Experimental verification of finite element enhancement and MAC methods  

E-Print Network [OSTI]

of Squares Analysis of MAC Matrices for the Pipe Model . . 128 . . 128 69. Creamer's Natural Frequencies - Pipe Model (Group 2) . . 129 LIST OF FIGURES Figure 1. Free-free Shaft Model Page 2. Cantilevered, Vertical Pipe Model 3. Graphic Illustration..., minimum changes are required in the analytical mass and stiffness matrices to produce results that match the measured natural frequency and mode shapes. Then, it is up to the analyst to assess the minimum relative change to determine the validity...

Ibrahim, Syed Azman

1991-01-01T23:59:59.000Z

194

Implementation of B-splines in a Conventional Finite Element Framework  

E-Print Network [OSTI]

continu- ity requirements for classical plate analysis. There is very good agreement between analytical and existing numerical solutions. PengCheng et al. utilized a multivariable spline element method to perform vibration analysis of plates [28... continu- ity requirements for classical plate analysis. There is very good agreement between analytical and existing numerical solutions. PengCheng et al. utilized a multivariable spline element method to perform vibration analysis of plates [28...

Owens, Brian C.

2010-01-16T23:59:59.000Z

195

Finite element analysis of laminar mixed convection in the entrance region of horizontal annular ducts  

SciTech Connect (OSTI)

The laminar mixed convection in the entrance region of horizontal straight ducts of an annular cross section is studied by means of a generally applicable finite element procedure based on the parabolized simplification of the Navier-Stokes and energy equations and on the Boussinesq approximation of the buoyancy term. The procedure is validated through comparisons of computed results with available data from the literature. New results concern annuli with radius ratios equal to 0.25, 0.5, and 0.75 subjected to the fundamental boundary condition of the second and the third kinds, for Prandtl numbers equal to 0.7 and 7, and different values of Grashof number.

Nonino, C.; Giudice, S. del [Univ. di Udine (Italy). Dipt. di Energetica e Macchine

1996-02-23T23:59:59.000Z

196

Modeling of reactor components using FIDAP: a finite element computer code  

E-Print Network [OSTI]

. ? e model are listed in table 1. 19 CHAPTER III FLUID AND THERMAL MIXING IN THE COLD LEG AND DOWNCOMER OF A PWR - A BENCHMARK In order to vahdste the code FIDAP, s, thermal mixing experiment is simulated This is basically a test of the field...MODELING OF REACTOR COMPONENTS USING FIDAP - A FINITE ELEMENT COMPUTE& CODE A Thesrs by ANAND GANGADHARAN Subnutted to the Office of Graduate Stuches of Texs, s ARM University in partial fulfillment of the requirements for the degree...

Gangadharan, Anand

2012-06-07T23:59:59.000Z

197

Three-dimensional finite element modeling of a magnet array spinning above a conductor  

SciTech Connect (OSTI)

Drag forces due to eddy currents induced by the relative motion of a conductor and a magnetic field occur in many practical devices: motors, brakes, magnetic bearings, and magnetically levitated vehicles. Recently, finite element codes have included solvers for 3-D eddy current geometries and have the potential to be very useful in the design and analysis of these devices. In this paper, numerical results from three-dimensional modeling of a magnet array spinning above a conductor are compared to experimental results in order to assess the capabilities of these codes.

Lorimer, W.L.; Lieu, D.K. [Univ. of California, Berkeley, CA (United States). Dept. of Mechanical Engineering; Hull, J.R.; Mulcahy, T.M.; Rossing, T.D. [Argonne National Lab., IL (United States)

1993-12-31T23:59:59.000Z

198

Defmod - Parallel multiphysics finite element code for modeling crustal deformation during the earthquake/rifting cycle  

E-Print Network [OSTI]

In this article, we present Defmod, a fully unstructured, two or three dimensional, parallel finite element code for modeling crustal deformation over time scales ranging from milliseconds to thousands of years. Defmod can simulate deformation due to all major processes that make up the earthquake/rifting cycle, in non-homogeneous media. Specifically, it can be used to model deformation due to dynamic and quasistatic processes such as co-seismic slip or dike intrusion(s), poroelastic rebound due to fluid flow and post-seismic or post-rifting viscoelastic relaxation. It can also be used to model deformation due to processes such as post-glacial rebound, hydrological (un)loading, injection and/or withdrawal of compressible or incompressible fluids from subsurface reservoirs etc. Defmod is written in Fortran 95 and uses PETSc's parallel sparse data structures and implicit solvers. Problems can be solved using (stabilized) linear triangular, quadrilateral, tetrahedral or hexahedral elements on shared or distribut...

Ali, S Tabrez

2014-01-01T23:59:59.000Z

199

An explicit finite element formulation for dynamic strain localization and damage evolution in metals  

SciTech Connect (OSTI)

An explicit finite element formulation, used to study the behavior and failure mechanisms of metallic materials under high strain rate loading, is presented. The formulation is based on the assumed-strain approach of Fish and Belytschko [1988], which allows localization bands to be embedded within an element, thereby alleviating mesh sensitivity and reducing the required computational effort. The behavior of the material outside localization bands (and of the virgin material prior to the onset of strain localization) is represented using a Gurson-type coupled plasticity-damage model based on the work of Johnson and Addessio [1988]. Assuming adiabatic conditions, the response of the localization band material is represented by a set of constitutive equations for large elasticviscoplastic deformations in metals at high strain rates and high homologous temperatures (see Brown et al. [1989]). Computational results are compared to experimental data for different metallic alloys to illustrate the advantages of the proposed modeling strategy.

Mourad, Hashem M [Los Alamos National Laboratory; Bronkhorst, Curt A [Los Alamos National Laboratory; Addessio, Francis L [Los Alamos National Laboratory

2010-12-16T23:59:59.000Z

200

Generalization of the Atkinson-Wilcox Theorem and the Development of a Novel Scaled Boundary Finite Element Formulation for the Numerical Simulation of Electromagnetic Radiation  

E-Print Network [OSTI]

The Scaled Boundary Finite Element Method is a novel semi-analytical method jointly developed by Chongmin Song and John P Wolf to solve problems in elastodynamics and allied problems in civil engineering. This novel method has been recently reformulated for the following categories of problems in electromagnetics: (1) Determination of Eigen values of metallic cavity structures, 2) Full wave analysis of Shielded micro-strip transmission line structures, and Very Large Scale Integrated Circuit (VLSI) interconnects, and 3) Full wave analysis of periodic structures. In this paper, a novel Scaled Boundary Finite Element formulation is developed for the numerical simulation of the time harmonic electromagnetic radiation in free space from metallic structures of arbitrary shape. The development of the novel formulation necessitates the generalization of the familiar Atkinson-Wilcox radiation series expansion so as to be applicable for arbitrary boundary circumscribing the source of radiation.

Rajan, V S P

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Automation of the matrix element reweighting method  

E-Print Network [OSTI]

Matrix element reweighting is a powerful experimental technique widely employed to maximize the amount of information that can be extracted from a collider data set. We present a procedure that allows to automatically evaluate the weights for any process of interest in the standard model and beyond. Given the initial, intermediate and final state particles, and the transfer functions for the final physics objects, such as leptons, jets, missing transverse energy, our algorithm creates a phase-space mapping designed to efficiently perform the integration of the squared matrix element and the transfer functions. The implementation builds up on MadGraph, it is completely automatized and publicly available. A few sample applications are presented that show the capabilities of the code and illustrate the possibilities for new studies that such an approach opens up.

P. Artoisenet; V. Lemaître; F. Maltoni; O. Mattelaer

2010-07-19T23:59:59.000Z

202

Two-dimensional thermo-mechanical finite element model for laser cladding  

SciTech Connect (OSTI)

Temperature and stress fields during Laser Cladding determine, respectively, the microstructure and residual stress induced deformation and crack formation. As laser cladding processes find application in manufacturing, understanding of the temperature and stress fields becomes crucial for development of the relationship between process parameters and service behavior. A two-dimensional model of laser cladding is developed, using the finite element software package ABAQUS. It enables an investigation of the temperature field that develops at the center plane of the material. This temperature field provides the input for a thermal stress analysis, for which generalized plane strain was assumed. The goal of the present paper is to perform a quantitative evaluation of the residual stresses that develop at the two-layered material, as a function of process parameters such as scanning speed, laser power and powder feed rate. Results of the model are presented, as applied to cladding of C95600 on AA333.

Deus, A.M. de; Mazumder, J. [Univ. of Illinois, Urbana-Champaign, IL (United States)

1996-12-31T23:59:59.000Z

203

Finite Element Analysis of the Amontons-Coulomb's Model using Local and Global Friction Tests  

SciTech Connect (OSTI)

In spite of the abundant number of experimental friction tests that have been reported, the contact with friction modeling persists to be one of the factors that determine the effectiveness of sheet metal forming simulation. This difficulty can be understood due to the nature of the friction phenomena, which comprises the interaction of different factors connected to both sheet and tools' surfaces. Although in finite element numerical simulations friction models are commonly applied at the local level, they normally rely on parameters identified based on global experimental tests results. The aim of this study is to analyze the applicability of the Amontons-Coulomb's friction coefficient identified using complementary tests: (i) load-scanning, at the local level and (ii) draw-bead, at the global level; to the numerical simulation of sheet metal forming processes.

Oliveira, M. C.; Menezes, L. F.; Ramalho, A. [CEMUC, Department of Mechanical Engineering, University of Coimbra, Polo II, Rua Luis Reis Santos, Pinhal de Marrocos, 3030-788 Coimbra (Portugal); Alves, J. L. [Department of Mechanical Engineering, University of Minho, Campus de Azurem, 4800-058, Guimaraes (Portugal)

2011-05-04T23:59:59.000Z

204

A new class of finite element variational multiscale turbulence models for incompressible magnetohydrodynamics  

E-Print Network [OSTI]

New large eddy simulation (LES) turbulence models for incompressible magnetohydrodynamics (MHD) derived from the variational multiscale (VMS) formulation for finite element simulations are introduced. The new models include the variational multiscale formulation, a residual-based eddy viscosity model, and a mixed model that combines both of these component models. Each model contains terms that are proportional to the residual of the incompressible MHD equations and is therefore numerically consistent. Moreover, each model is also dynamic, in that its effect vanishes when this residual is small. The new models are tested on the decaying MHD Taylor Green vortex at low and high Reynolds numbers. The evaluation of the models is based on comparisons with available data from direct numerical simulations (DNS) of the time evolution of energies as well as energy spectra at various discrete times. A numerical study, on a sequence of meshes, is presented that demonstrates that the large eddy simulation approaches the ...

Sondak, David; Oberai, Assad A; Pawlowski, Roger P; Cyr, Eric C; Smith, Tom M

2014-01-01T23:59:59.000Z

205

Long range propagation modeling of offshore wind turbine noise using finite element and parabolic equation models  

Science Journals Connector (OSTI)

Noise generated by offshore wind turbines and support structures radiates and propagates through the air water and sediment. Predicting noise levels around wind turbine structures at sea is required to estimate the effects of the noise on marine life. We used Finite Element(FE) and Parabolic Equation (PE) models to predict long range propagation of noise from the construction and operation of offshore wind turbines.FEanalysis produced pressure outputs at short ranges were used as a starting field for a modified PE propagation model. Furthermore we investigated the optimum range for the transition to PE modeling. The effects of various sediment types were also considered determining the pressure starting field. In FEanalysis models we implemented the axisymmetric elements and implicit dynamic analysis with pressureimpact loading and vertical acceleration boundary conditions to simulate pile driving and operational noise radiation. We will present the PE long range pressure field outputs from the offshore pile driving and operation for a shallow water environment around Block Island Rhode Island.

Huikwan Kim; Gopu R. Potty; James H. Miller; Kevin B. Smith; Georges Dossot

2012-01-01T23:59:59.000Z

206

Resolution of grain scale interactions using the Discrete Element Method  

E-Print Network [OSTI]

Granular materials are an integral part of many engineering systems. Currently, a popular tool for numerically investigating granular systems is the Discrete Element Method (DEM). Nearly all implementations of the DEM, ...

Johnson, Scott M. (Scott Matthew), 1978-

2006-01-01T23:59:59.000Z

207

Methods and devices for fabricating and assembling printable semiconductor elements  

DOE Patents [OSTI]

The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

Nuzzo, Ralph G. (Champaign, IL); Rogers, John A. (Champaign, IL); Menard, Etienne (Urbana, IL); Lee, Keon Jae (Savoy, IL); Khang, Dahl-Young (Urbana, IL); Sun, Yugang (Champaign, IL); Meitl, Matthew (Champaign, IL); Zhu, Zhengtao (Urbana, IL)

2009-11-24T23:59:59.000Z

208

Methods and devices for fabricating and assembling printable semiconductor elements  

DOE Patents [OSTI]

The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

Nuzzo, Ralph G; Rogers, John A; Menard, Etienne; Lee, Keon Jae; Khang, Dahl-Young; Sun, Yugang; Meitl, Matthew; Zhu, Zhengtao

2013-05-14T23:59:59.000Z

209

Methods and devices for fabricating and assembling printable semiconductor elements  

DOE Patents [OSTI]

The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

Nuzzo, Ralph G; Rogers, John A; Menard, Etienne; Lee, Keon Jae; Khang, Dahl-Young; Sun, Yugang; Meitl, Matthew; Zhu, Zhengtao

2014-03-04T23:59:59.000Z

210

Methods and devices for fabricating and assembling printable semiconductor elements  

DOE Patents [OSTI]

The invention provides methods and devices for fabricating printable semiconductor elements and assembling printable semiconductor elements onto substrate surfaces. Methods, devices and device components of the present invention are capable of generating a wide range of flexible electronic and optoelectronic devices and arrays of devices on substrates comprising polymeric materials. The present invention also provides stretchable semiconductor structures and stretchable electronic devices capable of good performance in stretched configurations.

Nuzzo, Ralph G. (Champaign, IL); Rogers, John A. (Champaign, IL); Menard, Etienne (Durham, NC); Lee, Keon Jae (Daejeon, KR); Khang, Dahl-Young (Urbana, IL); Sun, Yugang (Champaign, IL); Meitl, Matthew (Raleigh, NC); Zhu, Zhengtao (Urbana, IL)

2011-07-19T23:59:59.000Z

211

Transient finite element analysis of electric double layer using Nernst-Planck-Poisson equations with a modified stern layer  

E-Print Network [OSTI]

Finite element analysis of electric double layer capacitors using a transient nonlinear Nernst-Planck-Poisson (NPP) model and Nernst-Planck-Poisson-modified Stern layer (NPPMS) model are presented in 1D and 2D. The NPP model provided unrealistic ion...

Lim, Jong Il

2007-04-25T23:59:59.000Z

212

A ThreeDimensional Finite Element Simulation for Transport of Nuclear Waste Contamination in Porous Media \\Lambda  

E-Print Network [OSTI]

A Three­Dimensional Finite Element Simulation for Transport of Nuclear Waste Contamination for transport of nuclear­waste contamination in three­dimensional porous media are presented with a description of contamination of groundwater by high­level nuclear waste and a wide variety of other sources makes a proper

Ewing, Richard E.

213

Numerical simulation of borehole acoustic logging in the frequency and time domains with hp-adaptive finite elements  

E-Print Network [OSTI]

Numerical simulation of borehole acoustic logging in the frequency and time domains with hp elasticity Coupled problems hp-adaptive finite elements a b s t r a c t Accurate numerical simulation physical modeling combined with accurate and efficient numerical dis- cretization and solution techniques

Torres-Verdín, Carlos

214

Finite Element Solution of Nonlinear Transient Rock Damage with Application in Geomechanics of Oil and Gas Reservoirs  

E-Print Network [OSTI]

the geomechanics of oil and gas reservoirs. The fragile microstructure of some rocks makes it difficult to predict of Steel, Aluminum, Concrete, etc. Moreover, the pattern of rock damage in oil and gas reservoirsFinite Element Solution of Nonlinear Transient Rock Damage with Application in Geomechanics of Oil

Patzek, Tadeusz W.

215

High order finite difference methods with subcell resolution for stiff multispecies detonation capturing  

E-Print Network [OSTI]

High order finite difference methods with subcell resolution for stiff multispecies detonation words: stiff reaction term, shock capturing, detonation, WENO, ENO subcell resolution, multispecies

Shu, Chi-Wang

216

Utilization of a finite element model to verify spent nuclear fuel storage rack welds  

SciTech Connect (OSTI)

Elastic and plastic finite element analyses were performed for the inner tie block assembly of a 25 port fuel rack designed for installation at the Idaho National Engineering and Environmental Laboratory (INEEL) Idaho Chemical Processing Plant (ICPP). The model was specifically developed to verify the adequacy of certain welds joining components of the fuel storage rack assembly. The work scope for this task was limited to an investigation of the stress levels in the inner tie welds when the rack was subjected to seismic loads. Structural acceptance criteria used for the elastic calculations performed were as defined by the rack`s designer. Structural acceptance criteria used for the plastic calculations performed as part of this effort were as defined in Subsection NF and Appendix F of Section III of the ASME Boiler and Pressure Vessel Code. The results confirm that the welds joining the inner tie block to the surrounding rack structure meet the acceptance criteria. The analysis results verified that the inner tie block welds should be capable of transferring the expected seismic load without structural failure.

Nitzel, M.E.

1998-07-01T23:59:59.000Z

217

Electrical and thermal finite element modeling of arc faults in photovoltaic bypass diodes.  

SciTech Connect (OSTI)

Arc faults in photovoltaic (PV) modules have caused multiple rooftop fires. The arc generates a high-temperature plasma that ignites surrounding materials and subsequently spreads the fire to the building structure. While there are many possible locations in PV systems and PV modules where arcs could initiate, bypass diodes have been suspected of triggering arc faults in some modules. In order to understand the electrical and thermal phenomena associated with these events, a finite element model of a busbar and diode was created. Thermoelectrical simulations found Joule and internal diode heating from normal operation would not normally cause bypass diode or solder failures. However, if corrosion increased the contact resistance in the solder connection between the busbar and the diode leads, enough voltage potentially would be established to arc across micron-scale electrode gaps. Lastly, an analytical arc radiation model based on observed data was employed to predicted polymer ignition times. The model predicted polymer materials in the adjacent area of the diode and junction box ignite in less than 0.1 seconds.

Bower, Ward Isaac; Quintana, Michael A.; Johnson, Jay

2012-01-01T23:59:59.000Z

218

Finite element investigation of multi-phase transformation within carburized carbon steel  

Science Journals Connector (OSTI)

Mechanical components for the automobiles, aircrafts and machines are required to have the higher strength, hardness and wear resistance, when these parts are generally subjected to high load and impact. Such mechanical properties can be obtained from the carburization and quenching processes. Thus, in this study, numerical investigation using three-dimensional finite element technique was made to simulate the carburization and multi-phase transformation processes within the carburized carbon steel during quenching. In order to simulate the carburization process, the second Fick's equation and carbon diffusional equation were adapted. For numerical simulation of the diffusional phase transformation occurred during the non-isothermal quenching process, subdivision of the cooling curve into various small isothermal steps was introduced with the help of various time–temperature–transformation (TTT) diagrams of carbon steel. In addition, Scheil's additive rule and Johnson–Mehl–Avarami–Kolmogorov (JMAK) equation were also solved. On the other hand, Koistinen and Marburger's equation was used to model the diffusionless transformation. Through numerical analyses of carburization and quenching processes, the temperature and volume fraction of each phase were predicted for simple cylindrical specimen and complex geometries considering the latent heat generated during phase transformation. The numerical results compared well with the data available in the literature.

Seong-Hoon Kang; Yong-Taek Im

2007-01-01T23:59:59.000Z

219

Finite element modelling of transport and drift effects in tokamak divertor and SOL  

SciTech Connect (OSTI)

A finite element code is used to simulate transport of a single-species plasma in the edge and divertor of a tokamak. The physical model is based on Braginskii`s fluid equations for the conservation of particles, parallel momentum, ion and electron energy. In modelling recycling, transport of neutral density and energy is treated in the diffusion approximation. The electrostatic potential is obtained from the generalized Ohm`s law. It is used to compute the electric field and the associated E x B drift. In a first approximation, transport is assumed to be ambipolar. The system of equations is discretized on an unstructured triangular mesh, thus permitting good spatial resolution near the X-point and an accurate description of divertor plates of arbitrary shape. Special care must be taken to prevent numerical corruption of the highly anisotropic thermal diffusion. Comparisons will be made between simulations and experimental results from TdeV. This will focus, in particular, on density and temperature profiles at the divertor plates, and on the plasma parallel velocity in the SOL. The asymmetry in the power deposited to the inner and outer divertors and the effect of magnetic field reversal will be considered. Comparisons with B2-Eirene simulation results will also be presented.

Simard, M.; Marchand, R. [INRS-Energie et Materiaux, Varennes, Quebec (Canada); Boucher, C.; Gunn, J.P. [Centre Canadien de Fusion Magnetique, Varennes, Quebec (Canada)] [and others

1996-12-31T23:59:59.000Z

220

Finite element analysis of a crack tip in silicate glass: No evidence for a plastic zone  

Science Journals Connector (OSTI)

Recently, the claim was made that cracks in silicate glasses propagate by the nucleation, growth, and coalescence of cavities at crack tips, which is the same way as in metals but at a much smaller scale. This hypothesis for crack growth is based in part on the measurement of surface displacements near the tip of an emerging crack, which is the point at which a crack front intersects the side surface of the specimen. Surface displacements measured by atomic force microscopy were less than theoretically predicted. The difference between the theoretical and experimental displacements was attributed to a plastic zone surrounding the tip of the moving crack. In this paper, we show that the theoretical analysis used earlier was based on an incorrect assumption about the functional dependence of the displacement with distance from the crack tip. We use a full three-dimensional finite element analysis combined with an asymptotic solution of the crack geometry to obtain a solution to the surface displacement problem. We show that the calculated displacements are fully consistent with those experimentally measured by using an atomic force microscope. No divergence from elastic behavior is observed. Our results support the view that crack propagation in glass is entirely brittle. No evidence for plasticity at the crack tips is obtained.

T. Fett, G. Rizzi, D. Creek, S. Wagner, J. P. Guin, J. M. López-Cepero, and S. M. Wiederhorn

2008-05-15T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Failure of Mineralized Collagen Microfibrils Using Finite Element Simulation Coupled to Mechanical Quasi-brittle Damage  

E-Print Network [OSTI]

Bone is a multiscale heterogeneous materiel of which principal function is to support the body structure and to resist mechanical loading and fractures. Bone strength does not depend only on the quantity and quality of bone which is characterized by the geometry and the shape of bones but also on the mechanical proprieties of its compounds, which have a significant influence on its deformation and failure. This work aim to use a 3D nano-scale finite element model coupled to the concept of quasi-brittle damage with the behaviour law isotropic elasticity to investigate the fracture behaviour of composite materiel collagen-mineral (mineralized collagen microfibril). Fracture stress-number of cross-links and damping capacity-number of cross-links curves were obtained under tensile loading conditions at different densities of the mineral phase. The obtained results show that number of cross-links as well as the density of mineral has an important influence on the strength of microfibrils which in turn clarify the ...

Barkaoui, Abdelwahed; Hambli, Ridha; 10.1016/j.proeng.2011.04.526

2011-01-01T23:59:59.000Z

222

Quantum-corrected drift-diffusion models: Solution fixed point map and finite element approximation  

SciTech Connect (OSTI)

This article deals with the analysis of the functional iteration, denoted Generalized Gummel Map (GGM), proposed in [C. de Falco, A.L. Lacaita, E. Gatti, R. Sacco, Quantum-Corrected Drift-Diffusion Models for Transport in Semiconductor Devices, J. Comp. Phys. 204 (2) (2005) 533-561] for the decoupled solution of the Quantum Drift-Diffusion (QDD) model. The solution of the problem is characterized as being a fixed point of the GGM, which permits the establishment of a close link between the theoretical existence analysis and the implementation of a numerical tool, which was lacking in previous non-constructive proofs [N.B. Abdallah, A. Unterreiter, On the stationary quantum drift-diffusion model, Z. Angew. Math. Phys. 49 (1998) 251-275, R. Pinnau, A. Unterreiter, The stationary current-voltage characteristics of the quantum drift-diffusion model, SIAM J. Numer. Anal. 37 (1) (1999) 211-245]. The finite element approximation of the GGM is illustrated, and the main properties of the numerical fixed point map (discrete maximum principle and order of convergence) are discussed. Numerical results on realistic nanoscale devices are included to support the theoretical conclusions.

Falco, Carlo de [School of Mathematical Sciences, Dublin City University, Glasnevin, Dublin 9 (Ireland); Jerome, Joseph W. [Department of Mathematics, Northwestern University, 2033 Sheridan Road, Evanston, IL 60208-2730 (United States); Sacco, Riccardo [Dipartimento di Matematica 'F.Brioschi', Politecnico di Milano, via Bonardi 9, 20133 Milano (Italy)], E-mail: riccardo.sacco@polimi.it

2009-03-20T23:59:59.000Z

223

Finite element modeling of the temperature rise due to the propagation of ultrasonic waves in viscoelastic materials and experimental validation  

Science Journals Connector (OSTI)

The ultrasound stimulated thermography method is usually used to detect the temperature rise at a defect position. The temperature rise can be due to the friction between the edges of the defect and/or the plastic deformation around the defect. This paper presents another aspect of the method when the ultrasounds are propagating in a viscoelasticanisotropicmaterial such as polymers or fiber-reinforced polymers. The attenuation of the waves produces a distributed temperature field. Therefore even a defect that does not produce some heat can be detected the ultrasonic field is modified. A finite element model is used for computing the temperature field and for predicting the possibility for an infrared camera of detecting the temperature rise and its modification due to a defect. The model computes the stress and displacement fields associated with the propagation and the loss of energy. Then the heat equation is solved with this loss as a source of heating. An experiment is done with a sonotrode that excites a PVC plate. The ultrasonic displacement at the top of the plate is measured with a laser velocimeter and introduced in the model. Finally the model result is compared to the image produced by the camera.

B. Hosten; C. Bacon; C. Biateau

2008-01-01T23:59:59.000Z

224

Direct Forcing Immersed Boundary Methods: Finite Element Versus Finite Volume Approach  

E-Print Network [OSTI]

-facing step, two-dimensional flow past a stationary circular cylinder, three-dimensional flow past a sphere and two and three-dimensional natural convection in an enclosure with/without immersed body. The numerical results obtained with the discussed IFEM...

Frisani, Angelo 1980-

2012-12-07T23:59:59.000Z

225

Method and system for high power reflective optical elements  

DOE Patents [OSTI]

A method of repairing damage in an optical element includes providing a laser system including at least one optical element having a coating layer having an incident light surface and directing a laser pulse from the laser system to impinge on the incident light surface. The method also includes sustaining damage to a portion of the incident light surface and melting the damaged portion of the incident light surface and a region adjacent to the damaged portion. The method further includes flowing material from the region adjacent the damaged portion to the damaged portion and solidifying the material in the damaged portion and the region adjacent to the damaged portion.

Demos, Stavros G.; Rubenchik, Alexander M.; Negres, Raluca A.

2013-03-12T23:59:59.000Z

226

Stochastic finite difference lattice Boltzmann method for steady incompressible viscous flows  

SciTech Connect (OSTI)

With the advent of state-of-the-art computers and their rapid availability, the time is ripe for the development of efficient uncertainty quantification (UQ) methods to reduce the complexity of numerical models used to simulate complicated systems with incomplete knowledge and data. The spectral stochastic finite element method (SSFEM) which is one of the widely used UQ methods, regards uncertainty as generating a new dimension and the solution as dependent on this dimension. A convergent expansion along the new dimension is then sought in terms of the polynomial chaos system, and the coefficients in this representation are determined through a Galerkin approach. This approach provides an accurate representation even when only a small number of terms are used in the spectral expansion; consequently, saving in computational resource can be realized compared to the Monte Carlo (MC) scheme. Recent development of a finite difference lattice Boltzmann method (FDLBM) that provides a convenient algorithm for setting the boundary condition allows the flow of Newtonian and non-Newtonian fluids, with and without external body forces to be simulated with ease. Also, the inherent compressibility effect in the conventional lattice Boltzmann method, which might produce significant errors in some incompressible flow simulations, is eliminated. As such, the FDLBM together with an efficient UQ method can be used to treat incompressible flows with built in uncertainty, such as blood flow in stenosed arteries. The objective of this paper is to develop a stochastic numerical solver for steady incompressible viscous flows by combining the FDLBM with a SSFEM. Validation against MC solutions of channel/Couette, driven cavity, and sudden expansion flows are carried out.

Fu, S.C., E-mail: mm.scfu@polyu.edu.h [Mechanical Engineering Department, Hong Kong Polytechnic University, Hung Hom (Hong Kong); So, R.M.C. [Building Services Engineering Department, Hong Kong Polytechnic University, Hung Hom (Hong Kong); Mechanical Engineering Department, Purdue University, West Lafayette, IN 47907 (United States); Leung, W.W.F. [Research Institute of Innovative Products and Technologies, Hong Kong Polytechnic University, Hung Hom (Hong Kong)

2010-08-20T23:59:59.000Z

227

Finite element analysis and design of large diameter flexible vertical pipes subjected to incremental compacted backfill loads and creep effects  

E-Print Network [OSTI]

FINITE ELEMENT ANALYSIS AND DESiGN OF LARGE DIANETER FLEXIBLE VERTICAL PIPES SUBJECTED TO INCREMENTAL COMPACTED BACKFILL LOADS AND CREEP EFFECTS A Thesis by MOHAMMAD KABIR HOSSAIN Submitted to the Office of Graduate Studies of Texas A... BACKFILL LOADS AND CREEP EFFECTS A Thesis by MOHAMMAD KABIR HOSSAIN Approved as to sty1e and content by: R be+r L. Lytton (Chair of Committee) Ozden 0. Ochoa (Member) Derek V. Morris (Member) ames T P Yao (Head of rtment) ABSTRACT Finite...

Hossain, Mohammad Kabir

2012-06-07T23:59:59.000Z

228

Nonlinear acceleration of a continuous finite element discretization of the self-adjoint angular flux form of the transport equation  

SciTech Connect (OSTI)

Nonlinear acceleration of a continuous finite element (CFE) discretization of the transport equation requires a modification of the transport solution in order to achieve local conservation, a condition used in nonlinear acceleration to define the stopping criterion. In this work we implement a coarse-mesh finite difference acceleration for a CFE discretization of the second-order self adjoint angular flux (SAAF) form of the transport equation and use a post processing to enforce local conservation. Numerical results are given for one-group source calculations of one-dimensional slabs. We also give a formal derivation of the boundary conditions for the SAAF. (authors)

Sanchez, R. [Commissariat a l'Energie Atomique et Aux Energies Alternatives, Service des Etudes des Reacteurs et de Mathematiques Appliquees, CEA DEN/DM2S/SERMA, 91191 Gif-sur-Yvettes Cedex (France); Rabiti, C.; Wang, Y. [Idaho National Laboratory, 2525 Fremont Avenue, Idaho Falls, ID 83415 (United States)

2012-07-01T23:59:59.000Z

229

Higher-order finite volume methods II: Inf-sup condition and uniform local ellipticity  

Science Journals Connector (OSTI)

The main purpose of this paper is to study the construction of higher-order finite volume methods (FVMs) of triangle meshes. We investigate the relationship of the three theoretical notions crucial in the construction of FVMs: the uniform ellipticity ... Keywords: 65N12, 65N30, Finite volume methods, Uniform local ellipticity

Zhongying Chen, Yuesheng Xu, Yuanyuan Zhang

2014-08-01T23:59:59.000Z

230

Stress development and shape change during press-hardening process using phase-transformation-based finite element analysis  

Science Journals Connector (OSTI)

Abstract Elastically driven shape change, or springback, in a press-hardened U-channel part made from a tailor-welded blank (TWB) was simulated using a fully coupled thermo-mechanical–metallurgical finite element (FE) method. The TWB consists of boron steel and high-strength low-alloy steel, which have significantly different hardenabilities. A combined implicit–explicit three-step simulation consisting of air cooling, forming and die quenching, and springback was used for computational efficiency. All the required material models such as the modified phase-transformation kinetics and phase-transformation-related stress-update scheme were implemented in the FE software ABAQUS with the user-defined subroutines UMAT, VUMAT, and HETVAL. The developed FE procedure, including the material models, satisfactorily predicted the experimentally measured shape changes of the TWB part. Here we present an in-depth analysis of the residual stress development during forming and die quenching using different material modeling schemes. It should be noted that the stress evolution of the two materials with high and low hardenabilities were significantly different depending on the phase transformation kinetics during forming and quenching. Moreover, in order to enhance the prediction capability of the press-hardening simulations, it was essential to include the phase-transformation-related strains in the material model.

H.H. Bok; J.W. Choi; D.W. Suh; M.G. Lee; F. Barlat

2014-01-01T23:59:59.000Z

231

AN UPWIND FINITE-DIFFERENCE METHOD FOR TOTAL ...  

E-Print Network [OSTI]

A standard approach, as first suggested in [28], is to regularize the BV seminorm and ..... The result applied to our (finite-dimensional) problem gives the following: if 0 .... We did a series of experiments (a) to measure the ..... sets in the plane by the minimizing total variation flow, Interfaces Free Bound., 7 (2005), pp. 29–53.

2010-09-17T23:59:59.000Z

232

Rotordynamic analysis with shell elements for the transfer matrix method  

E-Print Network [OSTI]

Committee) Al B. elazzo1o (Member) John T. Tielki g (Member) Michael J. Rabins (Head of Department) August 1989 111 ABSTRACT Rotordynamic Analysis with Shell Elements for the Transi'er Matrix Method. (August 1989) Edward Anthony L'Antigua, B. M... theory. There have been recent publications proposing various methods for solving this problem of inaccuracy due to the beam modeling used in the transfer matrix approach. Rouch and Kao (1979), Nelson (1980), To (1981), Greenhill et al. , (1985...

L'Antigua, Edward Anthony

2012-06-07T23:59:59.000Z

233

Brueckner—Hartree—Fock Methods for Nuclear Matter and Finite Nuclei  

Science Journals Connector (OSTI)

In the present chapter we consider some methods developed during recent years for considering correlations in the relativistic description of the properties of nuclear matter and finite nuclei. First of all, w...

Professor Lev N. Savushkin…

2004-01-01T23:59:59.000Z

234

Mid-rise Building Progressive Collapse Finite Element Modeling with Consideration of Occupant Egress.  

E-Print Network [OSTI]

??A progressive collapse is characterized by initial local damage to a structural element leading to collapse of a large portion of the structure. Recently, investigation… (more)

Gabay, Zachary

2012-01-01T23:59:59.000Z

235

Efficient numerical methods for capacitance extraction based on boundary element method  

E-Print Network [OSTI]

algorithms based on boundary element methods (BEM) and to compute the capacitance extraction in the presence of floating dummy conductors. We propose the PHiCap algorithm, which is based on a hierarchical refinement algorithm and the wavelet transform. Unlike...

Yan, Shu

2006-04-12T23:59:59.000Z

236

A 2D finite element with through the thickness parabolic temperature distribution for heat transfer simulations including welding  

Science Journals Connector (OSTI)

Abstract The arc welding process involves thermal cycles that cause the appearance of undesirable residual stresses. The determination of this thermal cycle is the first step to a thermomechanical analysis that allows the numerical calculation of residual stresses. This study describes the formulation of a 2D finite element with through the thickness parabolic temperature distribution, including an element estabilization procedure. The 2D element described in this paper can be used to perform thermal analysis more economically than 3D elements, especially in plates, because the number of degrees of freedom through the thickness will always be three. A numerical model of a tungsten arc welding (GTAW) setup was made based on published experimental results. Size and distribution of the heat source input, thermal properties dependent on temperature, surface heat losses by convection and latent heat during phase change were considered. In parallel the same setup was modeled using ANSYS software with 3D elements (SOLID70) to compare against 2D numerical results. The results obtained by 2D model, 3D model and experimental data showed good agreement.

Darlesson Alves do Carmo; Alfredo Rocha de Faria

2015-01-01T23:59:59.000Z

237

Parallel Solution of the Wave Equation Using Higher Order Finite Elements  

E-Print Network [OSTI]

by stability constraints. One wants to do the same when solving with fi­ nite elements. However, except for preserving the stability of the scheme. We describe the new elements, referring the reader to [3] or [12 b = â?? 1 â?? 2 â?? 3 is a ``bubble'' function. The additional degree of freedom is the function value

Kern, Michel

238

Assessment of ground vibration impact from automotive and transit sources on future biotechnology research center using finite element analysis (FEA)  

Science Journals Connector (OSTI)

A new science and biotechnology research center was to be built in a metropolitan industrial area. There was concern that ground vibration from a nearby freeway street traffic and trains on an adjacent railroad would impact vibration sensitive research equipment inside the building. Ground vibration was measured at the project site prior to construction. Finite Element Analysis(FEA) was used to develop a computer simulation of the building structure using the measured ground vibration as input to the FEAmodel. The study determined the building floor vibration due to exterior sources would achieve the project’s criteria for the building structure as designed.

James E. Phillips

2007-01-01T23:59:59.000Z

239

Incorporation and modification of a shear deformable finite element into MARC  

E-Print Network [OSTI]

Calculation. Failure Progression Prediction. 2 4 6 8 9 10 QHD40 ELEMENT FUNDAMENTALS . . Review of QHD40 Element Displacement Field. Constitutive Relations. Interlaminar Stresses. 12 12 15 16 TAPER FORMULATION. 20 Taper Capabilities... 42 Cantilevered tapered plate . Page 65 43 Cross-sectional view of tapered laminate 44 Cantilevered plate with Sxg mesh and boundary conditions . . . . . 68 45 Tapered vs. flat plate deflection. . 69 46 Tapered plate transverse displacement. 47...

Hofman, Brad Burdell

2012-06-07T23:59:59.000Z

240

Development of a three-dimensional finite element model of a horse's foot  

E-Print Network [OSTI]

of a horse's foot and attempt to validate it using experimentally obtamed strain results. A Suite element model was constructed using geometric data &om traced outlines of slices cut lrom an actual foot. The model was analyzed using the ABAQUS Suite... element analysis code and strain results were obtamed which were found to difFer signi6cantly &om experimental resuhs. Based on iinformation from the literature, it was determmed that the structure of the model is essentially sound and discrepancies...

Hanft, Joseph Thomas

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

THE DENSITY OF STATES METHOD AT FINITE CHEMICAL POTENTIAL.  

SciTech Connect (OSTI)

We study the density of states method to explore the phase diagram of the chiral transition on the temperature and quark chemical potential plane. Four quark flavors are used in the analysis. Though the method is quite expensive small lattices show an indication for a triple-point connecting three different phases on the phase diagram.

SCHMIDT, C.; FODOR, Z.; KATZ, S.

2005-08-02T23:59:59.000Z

242

CIP/multi-moment finite volume method with arbitrary order of accuracy  

E-Print Network [OSTI]

This paper presents a general formulation of the CIP/multi-moment finite volume method (CIP/MM FVM) for arbitrary order of accuracy. Reconstruction up to arbitrary order can be built on single cell by adding extra derivative moments at the cell boundary. The volume integrated average (VIA) is updated via a flux-form finite volume formulation, whereas the point-based derivative moments are computed as local derivative Riemann problems by either direct interpolation or approximate Riemann solvers.

Xiao, Feng

2012-01-01T23:59:59.000Z

243

Fast finite-element calculation of gravity anomaly in complex geological regions  

Science Journals Connector (OSTI)

......accuracy of the FFEM in handling problems where the geometry...distribution of the material body are both far from...heterogeneity in the material body on the accuracy...Fig. 2). Figure 2 Diagram showing the geometry...The dimensions of the material body elements, empty......

Yongen Cai; Chi-yuen Wang

2005-09-01T23:59:59.000Z

244

Orientation dependent tensile deformation behavior of two-phase laminate composites: Model analysis and finite element results  

SciTech Connect (OSTI)

A model is presented which allows the distribution of stresses and strains within a two-phase laminate to be determined as a function of the angle between the normal vector to the laminate interfaces and the tensile axis during elastic and elastic-plastic deformation. The model is applied to {alpha}{sub 2}(Ti{sub 3}Al)/{gamma}(TiAl) and, for comparison, to Al/Al{sub 2}O{sub 3} laminates in order to study (a) the transfer of stresses between the two phases due to the mutual deformation constraint at the interphase boundaries and (b) the dependence of the yield stress on the orientation of the lamellae with respect to the tensile axis. The model predictions are in good agreement with the results of finite element computations within the composite except for certain boundary layers at the outer surfaces.

Mertins, H.; Lahann, H.J. [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Werkstofforschung] [GKSS-Forschungszentrum Geesthacht GmbH (Germany). Inst. fuer Werkstofforschung

1996-03-01T23:59:59.000Z

245

A Finite Element-Multibody Dynamics Co-simulation Methodology Applied to FAST  

E-Print Network [OSTI]

6 6 4 (Qv)R (Qv) (Qv)f 3 7 7 7 7 5 (2.7) The assembly is accomplished using a Boolean transformation matrix [24] which 23 identi es the connectivity conditions between the elements. The mass and sti ness matrix is given by the rst... external forces and Qv is the quadratic velocity vector. The detailed expression for the terms in the matrices is given by Shabana [24]. For the studies herein, the turbine rotation con ned to the rotor plane is assumed. Also, the blades are assumed...

Suryakumar, Vishvas Samuel

2013-05-02T23:59:59.000Z

246

Studying fast wave propagation and absorption at any cyclotron harmonic using a 2D finite element area coordinates wave equation solver  

SciTech Connect (OSTI)

Fourier analysis in the poloidal direction is a standard ingredient in present-day 2D wave equation solvers describing radio frequency waves in hot tokamak plasmas. Although a powerful and elegant technique, Fourier analysis has the disadvantage that a large number of modes is needed to describe the field pattern on a magnetic surface if a short wavelength mode exists on any - even very small - subpart of the particle trajectory. The present paper examines the potential of a method that does not suffer from this drawback: a finite element technique relying on simple linear or cubic area base functions that are defined on irregular elementary surfaces of triangular shape. The wave equation is solved in its weak Galerkin variational form and for realistic 2D tokamak geometry, accounting for the toroidal curvature but assuming the toroidal angle is ignorable, allowing to study the wave pattern for each of the independent toroidal modes excited by the antenna individually.The locally uniform full hot plasma dielectric tensor to all orders in finite Larmor radius was adopted. As the main intended application is the study of fast wave behavior (heating and current drive) at arbitrary harmonics, the wave vector complex amplitude appearing in the dielectric tensor is determined through a local dispersion root evaluation. High frequency fast wave propagation and damping is provided as an illustration in view of possible application of this type of current drive in future high density reactor-like tokamaks.

Lerche, Ernesto; Van Eester, Dirk [LPP-ERM/KMS, Association Euratom-'Belgian State', TEC Partner, Brussels (Belgium)

2011-12-23T23:59:59.000Z

247

One Time-step Finite Element Discretization of the Equation of Motion of Two-fluid Flows  

E-Print Network [OSTI]

at the boundary and at the interface between the two fluids. We discretize this system with the "mini boundary; "mini-element" INTRODUCTION This work is devoted to the numerical solution of the equations, an Arbitrary Lagrangian-Eulerian method of approximation (ALE), which is based on a grid that moves

Maury, Bertrand

248

On simple and accurate finite element models for nonlinear bending analysis of beams and plates  

E-Print Network [OSTI]

T x; dQTxx dx = ¡q(x) MTxx = Dxxd` T dx ; Q T x = AxzKs `T + dw T 0 dx ¶ (2.5a) 16 † The Reddy Beam Theory (RBT) dMRxx dx = Q R x +fi dPxx dx ¡flRx (2.6a) dQRx dx = q(x)+fl dRxx dx ¡fi d2Pxx dx2 (2.6b) MRxx = Dxxd` R dx ¡fiFxx d`R dx + d2wR0 dx2... >: ˆT for TBT U = „Dxx`RD xx ¡fiFxxdw R 0dx for simplifled RBT (2.12) A = 8 >>>> >> >: Dxx AxzKs for TBT ^Dxx „Axz for simplifled RBT (2.13) 18 B = 8> >>> >> >: 0 for TBT ^Dxx „Axz for simplifled RBT (2.14) II.2.3. A unifled flnite element model...

Urthaler Lapeira, Yetzirah Yksya

2007-09-17T23:59:59.000Z

249

Finite-difference time domain method for light scattering by small ice  

E-Print Network [OSTI]

can be employed to produce the scattering and ab- sorption characteristics of hexagonal ice particlesFinite-difference time domain method for light scattering by small ice crystals in three for the solution of light scattering by nonspherical particles has been developed for small ice crystals

Liou, K. N.

250

Finite Difference Methods for the Heat Equation MATH 418, PDE LAB Spring 2013  

E-Print Network [OSTI]

Finite Difference Methods for the Heat Equation MATH 418, PDE LAB Spring 2013 Lab #5 We seek numerical solutions of the heat equation u t = c2 2 u x2 , 0 0 (1) with boundary conditions u(0) Here x = L/(N + 1). The collection of points (4), (5) is called the computational grid. The matrix-grid

Bardsley, John

251

Stability Analysis for a Saline Boundary Layer Formed by Uniform Up ow Using Finite Elements  

E-Print Network [OSTI]

density in the deeper underground and high salt water density at the boundary layer), gravitation plays and Darcy's law. In this report we #12;rst give an overview of semi-analytical methods to analyse

Eindhoven, Technische Universiteit

252

E-Print Network 3.0 - atomic physics methods Sample Search Results  

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

element method in multiscale computation with applications to carbon nanotubes Summary: -dimensional atomic chain. ATOMIC-SCALE FINITE ELEMENT METHOD IN... PHYSICAL REVIEW B 72,...

253

Finite Element Modelling of the Sawing of DC Cast AA2024 Aluminium Alloy Slabs  

SciTech Connect (OSTI)

In the semi-continuous casting of large cross-section rolling sheet ingots of high-strength aluminum alloys (2xxx and 7xxx series), the control of the residual (internal) stresses generated by the non-uniform cooling becomes a necessity. These stresses must be relieved by a thermal treatment before the head and foot of the ingot can be cut. Otherwise, the saw can be caught owing to compressive stresses or cut parts may be ejected thus injuring people or damaging equipment. These high added-value ingots need to be produced in secure conditions. Moreover, a better control of the sawing procedure could allow the suppression of the thermal treatment and therefore save time and energy. By studying the stress build-up during casting and the stress relief during sawing, key parameters for the control and optimization of the processing steps, can be derived. To do so, the direct chill (DC) casting of the AA2024 alloy is modeled with ABAQUS 6.5 with special attention to the thermo-mechanical properties of the alloy. The sawing operation is then simulated by removing mesh elements so as to reproduce the progression of the saw in the ingot. Preliminary results showing the stress relief during sawing accompanied by the risk of saw blocking due to compression or initiating a crack ahead of the saw, are analyzed with an approach based on the rate of strain energy release.

Drezet, J.-M. [Computational Materials Laboratory, School of Engineering, Ecole Polytechnique Federale de Lausanne, Station 12, CH-1015 Lausanne (Switzerland); Ludwig, O. [Calcom-ESI SA, PSE-A, CH-1015 Lausanne (Switzerland); Heinrich, B. [Alcan Aluminium Valais SA, CH3960 Sierre (Switzerland)

2007-04-07T23:59:59.000Z

254

Rapid, automated imaging of mouse articular cartilage by microCT for early detection of osteoarthritis and finite element modelling of joint mechanics  

Science Journals Connector (OSTI)

SummaryObjective Mouse articular cartilage (AC) is mostly assessed by histopathology and its mechanics is poorly characterised. In this study: (1) we developed non-destructive imaging for quantitative assessment of AC morphology and (2) evaluated the mechanical implications of AC structural changes. Methods Knee joints obtained from naïve mice and from mice with osteoarthritis (OA) induced by destabilization of medial meniscus (DMM) for 4 and 12 weeks, were imaged by phosphotungstic acid (PTA) contrast enhanced micro-computed tomography (PTA-CT) and scored by conventional histopathology. Our software (Matlab) automatically segmented tibial AC, drew two regions centred on each tibial condyle and evaluated the volumes included. A finite element (FE) model of the whole mouse joint was implemented to evaluate AC mechanics. Results Our method achieved rapid, automated analysis of mouse AC (structural parameters in simulations estimated that AC thinning at early-stages in the DMM model (4 weeks) increases contact pressures (+39%) and Tresca stresses (+43%) in AC. Conclusion PTA-CT imaging is a fast and simple method to assess OA in murine models. Once applied more extensively to confirm its robustness, our approach will be useful for rapidly phenotyping genetically modified mice used for OA research and to improve the current understanding of mouse cartilage mechanics.

P. Das Neves Borges; A.E. Forte; T.L. Vincent; D. Dini; M. Marenzana

2014-01-01T23:59:59.000Z

255

APPLICATION OF BOUNDARY ELEMENT METHOD TO STREAMLINE GENERATION  

E-Print Network [OSTI]

Jitendra Kikani July 1989 Reservoir Simulation Industrial Affiliates #12;APPLICATION OF BOUNDARY ELEMENT injection, C02flooding, in-situ combustion). In addition impermeable barriers of any shape and orientation

Stanford University

256

Improved detection of rough defects for ultrasonic NDE inspections based on finite element modeling of elastic wave scattering  

SciTech Connect (OSTI)

Defects which posses rough surfaces greatly affect ultrasonic wave scattering behaviour, often reducing the magnitude of reflected signals. Ultrasonic inspections rely upon this response for detecting and sizing flaws. For safety critical components reliable characterisation is crucial. Therefore, providing an accurate means to predict reductions in signal amplitude is essential. An extension of Kirchhoff theory has formed the basis for the UK power industry inspection justifications. However, it is widely recognised that these predictions are pessimistic owing to analytical approximations. A numerical full field modelling approach does not fall victim to such limitations. Here, a Finite Element model is used to aid in setting a non-conservative reporting threshold during the inspection of a large pressure vessel forging that might contain embedded rough defects. The ultrasonic response from multiple rough surfaces defined by the same statistical class is calculated for normal incident compression waves. The approach is validated by comparing coherent scattering with predictions made by Kirchhoff theory. At lower levels of roughness excellent agreement is observed, whilst higher values confirm the pessimism of Kirchhoff theory. Furthermore, the mean amplitude in the specular direction is calculated. This represents the information obtained during an inspection, indicating that reductions due to increasing roughness are significantly less than the coherent component currently being used.

Pettit, J. R. [Rolls-Royce Nuclear, PO BOX 2000, Derby, UK, DE21 7XX and Research Centre for NDE, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom); Walker, A. [Rolls-Royce Nuclear, PO BOX 2000, Derby DE21 7XX (United Kingdom); Lowe, M. J. S. [Research Centre for NDE, Imperial College London, Exhibition Road, London SW7 2AZ (United Kingdom)

2014-02-18T23:59:59.000Z

257

Experimental and finite-element study of residual stresses in Zircaloy-4(R) and OFHC copper tubes  

SciTech Connect (OSTI)

Nonhomogeneous plastic deformation associated with metal-forming operations results in a state of residual stress in the final product. In the experimental phase of this study, residual stress distribution in Zr-4(R) and copper tubes is determined by electropolishing the outer (or inner) and surface of the tubes while measuring the developed strains at the inner (or outer) surface. Material removal by electropolishing proved to be an efficient and suitable technique due to its constant mass removal rate under conditions which do not alter the patter of residual stresses in the specimen. In the case of Zr-4(R) specimens, experiments were conducted on the as-received (stress relieved) as well as specimens annealed at 500 C for one hour. The effect of various degrees of cold working on the residual stress patterns of drawn copper tubing is determined by performing similar experiments on soft, 1/4-hard, 1/2-hard, and hard temper, OFHC copper specimens. In the second phase of this investigation, an elastic-plastic finite-element code (ABAQUS) is employed in a parametric study to determined the optimum processing conditions for drawing copper tubes.

Rasty, J.

1987-01-01T23:59:59.000Z

258

Numerical simulation of wind resonance of a circular profile by means of the vortex element method  

Science Journals Connector (OSTI)

The problem regarding the numerical simulation of a circular profile motion in a ... element method is used. The phenomenon of wind resonance has been examined. The investigation has...

I. K. Marchevskii; O. I. Ivanov

2009-10-01T23:59:59.000Z

259

Experimental and finite element analysis research on cold-formed steel lipped channel beams under web crippling  

Science Journals Connector (OSTI)

Abstract This article presents the results of an investigation into web crippling behavior of cold-formed steel lipped channel beams subjected to end-one-flange (EOF), interior-one-flange (IOF), end-two-flange (ETF), and interior-two-flange (ITF) loading conditions. A total of 48 cold-formed steel lipped channel beams with different boundary conditions, loading conditions, bearing lengths, and section heights were tested. The experimental scheme, failure modes, concentrated load-general vertical deformation and strain intensity distribution curves are presented in the article. The effect of boundary condition, loading condition, bearing length and section height on web crippling ultimate capacity and ductility of cold-formed steel lipped channel beams was also studied. Results of these tests show that the effect of bearing length on the web crippling ultimate capacity in EOF and ETF loading conditions is more obvious than those in IOF and ITF loading conditions. When bearing length is 50, 100, and 150 mm, web crippling ultimate capacity of cold-formed steel lipped channel beams with web slenderness=78 reaches its peak. The middle web enters plasticity and form plastic hinge zone. The values of web crippling ultimate capacity in interior-flange loading conditions are larger than those in end-flange loading conditions. It is shown that the specimens in the interior-flange loading conditions have higher ultimate capacity, larger initial stiffness and better ductility than those of specimens in the end-flange loading conditions. Finite element analysis can simulate experimental failure mode and web crippling ultimate capacity. The calculation equations of web crippling ultimate capacity put forward in the article can accurately predict experimental value.

Yu Chen; Xixiang Chen; Chaoyang Wang

2015-01-01T23:59:59.000Z

260

Investigation of water and CO2 (carbon dioxide) flooding using micro-CT (micro-computed tomography) images of Berea sandstone core using finite element simulations  

Science Journals Connector (OSTI)

The present study reports a numerical investigation of water and CO2 (carbon dioxide) flooding at the pore scale of a porous medium. We use high resolution micro-computed tomography (micro-CT) images of Berea sandstone core to obtain the pore geometry. The numerical solution used for the simulation was carried out by a finite element based software package. Level Set method is used to determine the position of the interface between two immiscible fluids when oil is displaced by water and CO2, respectively. The present formulation is validated against single-phase flow through the porous structure. It is found that, fluid flow inside the pore space takes place through preferential inlet and outlet pores. For two-phase flow, it is observed that continuous displacement of oil occurs during water flooding but CO2 is able to displace oil at certain locations in the pores. Also, the separation of flow front is observed in the case of CO2 flooding. A quantitative comparison of the results obtained in two types of flooding simulations suggests that water displaces a higher volume of oil than CO2 in the time period for which the simulations are performed.

Akshay C. Gunde; Bijoyendra Bera; Sushanta K. Mitra

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

An advanced 3D boundary element method for characterizations of composite materials  

E-Print Network [OSTI]

An advanced 3D boundary element method for characterizations of composite materials X.L. Chena , Y developments in the modeling of composite materials using the boundary element method (BEM) are presented in dealing with nearly-singular integrals, which arise in the BEM modeling of composite materials

Liu, Yijun

262

STEIN'S METHOD, HEAT KERNEL, AND TRACES OF POWERS OF ELEMENTS OF COMPACT LIE GROUPS  

E-Print Network [OSTI]

STEIN'S METHOD, HEAT KERNEL, AND TRACES OF POWERS OF ELEMENTS OF COMPACT LIE GROUPS JASON FULMAN Abstract. Combining Stein's method with heat kernel techniques, we show that the trace of the jth power There is a large literature on the traces of powers of random elements of compact Lie groups. One of the earliest

Fulman, Jason

263

STEIN'S METHOD, HEAT KERNEL, AND TRACES OF POWERS OF ELEMENTS OF COMPACT LIE GROUPS  

E-Print Network [OSTI]

STEIN'S METHOD, HEAT KERNEL, AND TRACES OF POWERS OF ELEMENTS OF COMPACT LIE GROUPS JASON FULMAN Abstract. Combining Stein's method with heat kernel techniques, we show that the trace of the jth power on the traces of powers of random elements of compact Lie groups. One of the earliest results is due to Diaconis

Fulman, Jason

264

Determination of the effect of part orientation to the strength value on additive manufacturing FDM for end-use parts by physical testing and validation via three-dimensional finite element analysis  

Science Journals Connector (OSTI)

Determining the mechanical properties of the parts manufactured from additive manufacturing (AM) technology is important for manufacture end-use functional parts, known as rapid manufacturing (RM). It is important, within RM design, to verify to some degree of confidence that a part designed to be manufactured using this technology will be suitable and fit to function as intended, prior to committing to manufacture. The method of doing this is to perform physical testing on fabricated parts and validate via finite element analysis (FEA) on the parts.

R.H. Hambali; P. Smith; A.E.W. Rennie

2012-01-01T23:59:59.000Z

265

Computational upscaled modeling of heterogeneous porous media flow utilizing finite volume method  

E-Print Network [OSTI]

-Gupta (Member) Al Boggess (Head of Department) May 2004 Major Subject: Mathematics iii ABSTRACT Computational Upscaled Modeling of Heterogeneous Porous Media Flow Utilizing Finite Volume Method. (May 2004) Victor Eralingga Ginting, B.S., Institute of Technology... of L2 norm of solution error for =h = 0:64, and n = 16. 39 3.6 Comparison of L2 norm of solution error for N = 32. : : : : : : : : : 39 3.7 Results for anisotropic case, lx1 = 0:40, lx2 = 0:01, = 1:0. : : : : : : 41 3.8 Results for anisotropic case...

Ginting, Victor Eralingga

2005-08-29T23:59:59.000Z

266

Vocal tract changes caused by phonation into a tube: A case study using computer tomography and finite-element modeling  

Science Journals Connector (OSTI)

Phonation into a glass tube is a voice training and therapy method that leads to beneficial effects in voice production. It has not been known however what changes occur in the vocal tract during and after the phonation into a tube. This pilot study examined the vocal tract shape in a female subject before during and after phonation into a tube using computer tomography(CT). Three-dimensional finite-elementmodels (FEMs) of the vocal tract were derived from the CTimages and used to study changes in vocal tract input impedance. When phonating on vowel [a:] the data showed tightened velopharyngeal closure and enlarged cross-sectional areas of the oropharyngeal and oral cavities during and after the tube-phonation. FEM calculations revealed an increased input inertance of the vocal tract and an increased acoustic energy radiated out of the vocal tract after the tube-phonation. The results indicate that the phonation into a tube causes changes in the vocal tract which remain also when the tube is removed. These effects may help improving voice production in patients and voice professionals.

Tomáš Vampola; Anne-Maria Laukkanen; Jaromír Horá?ek; Jan G. Švec

2011-01-01T23:59:59.000Z

267

Methods for making a porous nuclear fuel element  

SciTech Connect (OSTI)

Porous nuclear fuel elements for use in advanced high temperature gas-cooled nuclear reactors (HTGR's), and to processes for fabricating them. Advanced uranium bi-carbide, uranium tri-carbide and uranium carbonitride nuclear fuels can be used. These fuels have high melting temperatures, high thermal conductivity, and high resistance to erosion by hot hydrogen gas. Tri-carbide fuels, such as (U,Zr,Nb)C, can be fabricated using chemical vapor infiltration (CVI) to simultaneously deposit each of the three separate carbides, e.g., UC, ZrC, and NbC in a single CVI step. By using CVI, the nuclear fuel may be deposited inside of a highly porous skeletal structure made of, for example, reticulated vitreous carbon foam.

Youchison, Dennis L; Williams, Brian E; Benander, Robert E

2014-12-30T23:59:59.000Z

268

Physiological observations validate finite element models for estimating subject-specific electric field distributions induced by transcranial magnetic stimulation of the human motor cortex  

Science Journals Connector (OSTI)

Abstract Recent evidence indicates subject-specific gyral folding patterns and white matter anisotropy uniquely shape electric fields generated by TMS. Current methods for predicting the brain regions influenced by TMS involve projecting the TMS coil position or center of gravity onto realistic head models derived from structural and functional imaging data. Similarly, spherical models have been used to estimate electric field distributions generated by TMS pulses delivered from a particular coil location and position. In the present paper we inspect differences between electric field computations estimated using the finite element method (FEM) and projection-based approaches described above. We then more specifically examined an approach for estimating cortical excitation volumes based on individualistic FEM simulations of electric fields. We evaluated this approach by performing neurophysiological recordings during MR-navigated motormapping experiments. We recorded motor evoked potentials (MEPs) in response to single pulse TMS using two different coil orientations (45° and 90° to midline) at 25 different locations (5 × 5 grid, 1 cm spacing) centered on the hotspot of the right first dorsal interosseous (FDI) muscle in left motor cortex. We observed that motor excitability maps varied within and between subjects as a function of TMS coil position and orientation. For each coil position and orientation tested, simulations of the TMS-induced electric field were computed using individualistic FEM models and compared to MEP amplitudes obtained during our motormapping experiments. We found FEM simulations of electric field strength, which take into account subject-specific gyral geometry and tissue conductivity anisotropy, significantly correlated with physiologically observed MEP amplitudes (rmax = 0.91, p = 1.8 × 10-5 rmean = 0.81, p = 0.01). These observations validate the implementation of individualistic FEM models to account for variations in gyral folding patterns and tissue conductivity anisotropy, which should help improve the targeting accuracy of TMS in the mapping or modulation of human brain circuits.

Alexander Opitz; Wynn Legon; Abby Rowlands; Warren K. Bickel; Walter Paulus; William J. Tyler

2013-01-01T23:59:59.000Z

269

FINITE GROUPS WITH TWO CONJUGACY CLASSES OF p-ELEMENTS AND RELATED QUESTIONS FOR p-BLOCKS  

E-Print Network [OSTI]

K¨ULSHAMMER, GABRIEL NAVARRO, BENJAMIN SAMBALE, AND PHAM HUU TIEP Abstract. We prove that a finite:01:25 BST Version 2 - Submitted to BLMS #12;2 K¨ULSHAMMER, NAVARRO, SAMBALE, AND TIEP Theorem A can

270

Method for the removal of elemental mercury from a gas stream  

DOE Patents [OSTI]

A method is provided to remove elemental mercury from a gas stream by reacting the gas stream with an oxidizing solution to convert the elemental mercury to soluble mercury compounds. Other constituents are also oxidized. The gas stream is then passed through a wet scrubber to remove the mercuric compounds and oxidized constituents.

Mendelsohn, Marshall H. (Downers Grove, IL); Huang, Hann-Sheng (Darien, IL)

1999-01-01T23:59:59.000Z

271

CONVERGENCE OF AN IMPLICIT FINITE ELEMENT METHOD FOR THE LANDAU-LIFSHITZ-GILBERT EQUATION  

E-Print Network [OSTI]

is based on a reformation of (1.1) by Gilbert (see, e.g. [5]), mt - m Ã? mt = (1 + 2 ) m Ã? m . Given

Bartels, Soeren

272

Decoupled Modeling of Chilled Water Cooling Coils Using a Finite Element Method  

E-Print Network [OSTI]

&M University Abstract Chilled water cooling coils are important components in air handling unit systems. Generally the cooling coil removes both moisture and sensible heat from entering air. Since the sensible and latent heat transfer modes are coupled... and the saturation humidity ratio vs. temperature curve on the psychrometric chart is non-linear, it is very difficult to solve cooling coil heat transfer differential equations across the entire coil. However, the sensible and latent heat transfer modes can...

Wang, G.; Liu, M.

2005-01-01T23:59:59.000Z

273

Deformation Effects in One and Two Chiral Bags Studied with Use of the Finite Element Method  

Science Journals Connector (OSTI)

......Current interest on nuclear forces is focused on...understanding from the sub-nuclear level. With such a motivation...6) with use of low energy effective models of QCD...shown that the lowest energy solu- tion has a doughnut...and the members of his nuclear theory group for their......

Shin-ichi Nawa

1991-08-01T23:59:59.000Z

274

k - Version of Finite Element Method for Polymer flows using Giesekus Constitutive Model  

E-Print Network [OSTI]

. It is shown that in the hpk framework when hd goes to 0 and k goes to infinity, physics is approached where the lid meets the stationary vertical walls. Various numerical studies are presented upto deborah number of 2.4 for hd = 0.1 and 0.05. The converged...

Deshpande, Kedar M.

2008-01-31T23:59:59.000Z

275

Prediction of fluid flow in curved pipe using the finite element method  

E-Print Network [OSTI]

by Boussinesq, equation (1), with two additional equations, one for turbulent kinetic energy (k) and one for dissipation (e). Using equation (1), the Reynolds stress term in the momentum equation, equation (19), can be written ss: (20) If we define the total... by Boussinesq, equation (1), with two additional equations, one for turbulent kinetic energy (k) and one for dissipation (e). Using equation (1), the Reynolds stress term in the momentum equation, equation (19), can be written ss: (20) If we define the total...

Maitin, Christopher Benjamin

2012-06-07T23:59:59.000Z

276

Modeling Slag Penetration and Refractory Degradation Using the Finite Element Method  

SciTech Connect (OSTI)

Refractory degradation due to slag penetration can significantly reduce the service life of gasifier refractory linings. This paper describes a modeling approach that was developed to predict refractory spalling as a function of operating temperature, coal feedstock and refractory type. The model simulates the coupled thermal, diffusion, and mechanical interactions of coal slag with refractory ceramics. The heat transfer and slag diffusion solutions are directly coupled through a temperature-dependent effective diffusivity for slag penetration. The effective diffusivity is defined from slag penetration tests conducted in our laboratories on specific coal slag and refractory combinations. Chemically-induced swelling of the refractory and the build-up of mechanical stresses are functions of the slag penetration. The model results are compared with analytical spalling models and validated by experimental data in order to develop an efficient refractory degradation model for implementation in a systems level gasifier model. The ultimate goal of our research is to provide a tool that will help optimize gasifier performance by balancing conversion efficiency with refractory life.

Johnson, Kenneth I.; Williford, Ralph E.; Matyas, Josef; Pilli, Siva Prasad; Sundaram, S. K.; Korolev, Vladimir N.

2008-09-01T23:59:59.000Z

277

A Finite-element Front-tracking Enthalpy Method for Stefan Problems  

Science Journals Connector (OSTI)

......IC. u(x,0)=f{x), 0 0, Define the enthalpy ff by u > 0 , ), = 0, .C2u, u dx+\\H4>dx+\\ Hdx......

CHIN HSIEN LI

1983-01-01T23:59:59.000Z

278

Thermo-Poroelastic Modeling of Reservoir Stimulation and Microseismicity Using Finite Element Method with Damage Mechanics  

E-Print Network [OSTI]

Stress and permeability variations around a wellbore and in the reservoir are of much interest in petroleum and geothermal reservoir development. Water injection causes significant changes in pore pressure, temperature, and stress in hot reservoirs...

Lee, Sang Hoon

2012-02-14T23:59:59.000Z

279

A parallel finite-element method for three-dimensional controlled-source electromagnetic forward modelling  

Science Journals Connector (OSTI)

......of classical QMR), but have minimal storage requirements. A variation of QMR for...of them do not require computation and storage. The construction of this pre-conditioner...geometry: two half-spaces that represent seawater (sigma0 = 3.3Sm 1) and sediments......

Vladimir Puzyrev; Jelena Koldan; Josep de la Puente; Guillaume Houzeaux; Mariano Vázquez; José María Cela

2013-01-01T23:59:59.000Z

280

Two Fluid Space-Time Discontinuous Galerkin Finite Element Method. Part I: Numerical Algorithm  

E-Print Network [OSTI]

, due to surface tension and other effects. In addition, the density and pressure differences across. Small cells arising from the cut-cell refinement are merged to improve the stability and performance, liquids and solids and have many applications in nature and industry. Examples include flows with bubbles

Al Hanbali, Ahmad

Note: This page contains sample records for the topic "finite element method" 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

Space-Time Discontinuous Galerkin Finite Element Method for Two-Fluid Flows.  

E-Print Network [OSTI]

different fluids, due to surface tension and other effects. In addition, the density and pressure arising from the cut-cell refinement are merged to improve the stability and performance. The interface flows with bubbles, droplets or solid particles, wave-structure interactions, dam breaking, bed

Al Hanbali, Ahmad

282

Detecting and modeling cement failure in high pressure/ high temperature wells using finite-element method  

E-Print Network [OSTI]

. In the event that high-pressure and high-temperature (HPHT) conditions are encountered, we must attempt to achieve permeability in the set cement to prevent gas migration and to prevent any other fluid passing through to collapse the entire structure. Therefore...

Shahri, Mehdi Abbaszadeh

2006-04-12T23:59:59.000Z

283

Studies on Nano-Indentation of Polymeric Thin Films Using Finite Element Methods  

E-Print Network [OSTI]

In this paper, the numerical simulation for nano-indentation is performed to measure time-dependent behavior of polymeric films. The possibility to extract the relaxed shear modulus of the polymer is evaluated using a rigid ...

Shen, Xiaojun

284

Evolving crack patterns in thin films with the extended finite element method  

E-Print Network [OSTI]

-exist in the film. To describe subcritical crack growth, we prescribe a kinetic law that relates the crack velocity is susceptible to subcritical cracking, obeying a kinetic law that relates the velocity of each crack to its Elsevier Science Ltd. All rights reserved. Keywords: Crack patterns; Subcritical cracking; Thin films

Suo, Zhigang

285

Apparatus for and method of monitoring for breached fuel elements  

DOE Patents [OSTI]

This invention teaches improved apparatus for the method of detecting a breach in cladded fuel used in a nuclear reactor. The detector apparatus uses a separate bypass loop for conveying part of the reactor coolant away from the core, and at least three separate delayed-neutron detectors mounted proximate this detector loop. The detectors are spaced apart so that the coolant flow time from the core to each detector is different, and these differences are known. The delayed-neutron activity at the detectors is a function of the dealy time after the reaction in the fuel until the coolant carrying the delayed-neutron emitter passes the respective detector. This time delay is broken down into separate components including an isotopic holdup time required for the emitter to move through the fuel from the reaction to the coolant at the breach, and two transit times required for the emitter now in the coolant to flow from the breach to the detector loop and then via the loop to the detector. At least two of these time components are determined during calibrated operation of the reactor. Thereafter during normal reactor operation, repeated comparisons are made by the method of regression approximation of the third time component for the best-fit line correlating measured delayed-neutron activity against activity that is approximated according to specific equations. The equations use these time-delay components and known parameter values of the fuel and of the part and emitting daughter isotopes.

Gross, Kenny C. (Lemont, IL); Strain, Robert V. (Woodbridge, IL)

1983-01-01T23:59:59.000Z

286

Accurate, finite-volume methods for 3D MHD on unstructured Lagrangian meshes  

SciTech Connect (OSTI)

Previous 2D methods for magnetohydrodynamics (MHD) have contributed both to development of core code capability and to physics applications relevant to AGEX pulsed-power experiments. This strategy is being extended to 3D by development of a modular extension of an ASCI code. Extension to 3D not only increases complexity by problem size, but also introduces new physics, such as magnetic helicity transport. The authors have developed a method which incorporates all known conservation properties into the difference scheme on a Lagrangian unstructured mesh. Because the method does not depend on the mesh structure, mesh refinement is possible during a calculation to prevent the well known problem of mesh tangling. Arbitrary polyhedral cells are decomposed into tetrahedrons. The action of the magnetic vector potential, A {center_dot} {delta}l, is centered on the edges of this extended mesh. For ideal flow, this maintains {del} {center_dot} B = 0 to round-off error. Vertex forces are derived by the variation of magnetic energy with respect to vertex positions, F = {minus}{partial_derivative}W{sub B}/{partial_derivative}r. This assures symmetry as well as magnetic flux, momentum, and energy conservation. The method is local so that parallelization by domain decomposition is natural for large meshes. In addition, a simple, ideal-gas, finite pressure term has been included. The resistive diffusion part is calculated using the support operator method, to obtain an energy conservative, symmetric method on an arbitrary mesh. Implicit time difference equations are solved by preconditioned, conjugate gradient methods. Results of convergence tests are presented. Initial results of an annular Z-pinch implosion problem illustrate the application of these methods to multi-material problems.

Barnes, D.C.; Rousculp, C.L.

1998-10-01T23:59:59.000Z

287

Solving transient conduction and radiation heat transfer problems using the lattice Boltzmann method and the finite volume method  

SciTech Connect (OSTI)

The lattice Boltzmann method (LBM) was used to solve the energy equation of a transient conduction-radiation heat transfer problem. The finite volume method (FVM) was used to compute the radiative information. To study the compatibility of the LBM for the energy equation and the FVM for the radiative transfer equation, transient conduction and radiation heat transfer problems in 1-D planar and 2-D rectangular geometries were considered. In order to establish the suitability of the LBM, the energy equations of the two problems were also solved using the FVM of the computational fluid dynamics. The FVM used in the radiative heat transfer was employed to compute the radiative information required for the solution of the energy equation using the LBM or the FVM (of the CFD). To study the compatibility and suitability of the LBM for the solution of energy equation and the FVM for the radiative information, results were analyzed for the effects of various parameters such as the scattering albedo, the conduction-radiation parameter and the boundary emissivity. The results of the LBM-FVM combination were found to be in excellent agreement with the FVM-FVM combination. The number of iterations and CPU times in both the combinations were found comparable.

Mishra, Subhash C. [Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039 (India)]. E-mail: scm_iitg@yahoo.com; Roy, Hillol K. [Department of Mechanical Engineering, Indian Institute of Technology Guwahati, Guwahati 781039 (India)

2007-04-10T23:59:59.000Z

288

Three-dimensional thermo-elastic–plastic finite element modeling of quenching process of plain-carbon steel in couple with phase transformation  

Science Journals Connector (OSTI)

This study focuses on finite element investigations of quenching process which is commonly applied to improve mechanical properties such as strength, hardness, and wear/fatigue resistances, etc. During the quenching process, various kinds of microstructures evolve depending on the cooling rate and temperature variation within the steel. This microstructural evolution has a significant effect on the final dimension and geometry of the mechanical parts. In order to investigate the effect of temperature variation and phase transformation on the dimensional change and stress distribution, thermo-elastic–plastic constitutive equation coupled with the mechanical strain, thermal strain, phase transformation strain, and transformation induced plasticity is described in detail. Using the constitutive equation introduced, a finite element program was developed and used to predict distributions of the temperature, volume fraction of each phase transformed, and stress and dimensional change of the cylindrical specimen, shaft with key groove, and cam-lobe made of carbon steel. It was found out that numerically obtained values such as temperature history and stress distribution were in good agreement with the data available in the literature for the cylindrical carbon steel specimen. The developed program can be used for better understanding of mechanics involved with the quenching process.

Seong-Hoon Kang; Yong-Taek Im

2007-01-01T23:59:59.000Z

289

Finite-frequency sensitivity kernels for global seismic wave propagation based upon adjoint methods  

Science Journals Connector (OSTI)

......wave. P-wave energy enters the shadow...generally has a lower frequency content compared...simulate the seismic response of 2D and 3D geological...2006. Finite-frequency Kernels based upon...2004. Finite-frequency tomography reveals...Circumventing storage limitations in variational......

Qinya Liu; Jeroen Tromp

2008-07-01T23:59:59.000Z

290

The Method of Lines for the Analysis of Microstrip Lines on the Finite Width Substrate  

Science Journals Connector (OSTI)

A full-wave analysis of the electrical characteristics of the microstrip lines on the finite width substrate is presented. The substrate layer of the microstrip line must be treated as an inhomogeneous layer. ......

Bo Gao; Ling Tong; Xun Gong

2009-06-01T23:59:59.000Z

291

Finite-Temperature Non-equilibrium Quasicontinuum Method based on Langevin Dynamics  

SciTech Connect (OSTI)

The concurrent bridging of molecular dynamics and continuum thermodynamics presents a number of challenges, mostly associated with energy transmission and changes in the constitutive description of a material across domain boundaries. In this paper, we propose a framework for simulating coarse dynamic systems in the canonical ensemble using the Quasicontinuum method (QC). The equations of motion are expressed in reduced QC coordinates and are strictly derived from dissipative Lagrangian mechanics. The derivation naturally leads to a classical Langevin implementation where the timescale is governed by vibrations emanating from the finest length scale occurring in the computational cell. The equations of motion are integrated explicitly via Newmark's ({beta} = 0; {gamma} = 1/2) method, leading to a robust numerical behavior and energy conservation. In its current form, the method only allows for wave propagations supported by the less compliant of the two meshes across a heterogeneous boundary, which requires the use of overdamped dynamics to avoid spurious heating due to reflected vibrations. We have applied the method to two independent crystallographic systems characterized by different interatomic potentials (Al and Ta) and have measured thermal expansion in order to quantify the vibrational entropy loss due to homogenization. We rationalize the results in terms of system size, mesh coarseness, and nodal cluster diameter within the framework of the quasiharmonic approximation. For Al, we find that the entropy loss introduced by mesh coarsening varies linearly with the element size, and that volumetric effects are not critical in driving the anharmonic behavior of the simulated systems. In Ta, the anomalies of the interatomic potential employed result in negative and zero thermal expansion at low and high temperatures, respectively.

Marian, J; Venturini, G; Hansen, B; Knap, J; Ortiz, M; Campbell, G

2009-05-08T23:59:59.000Z

292

Development of fatigue stress spectrum and fatigue life prediction of endless winder sheave for wind turbine lift using finite element analysis  

Science Journals Connector (OSTI)

This paper aims to develop the fatigue stress spectrum and predicted fatigue life of the endless winder sheave using finite element (FE) analysis which is utilized in wind turbine lift. First we identified the fatigue critical location (FCL) of endless winder sheave through a static FE analysis. And the lifting velocity was measured using the non-contact velocity dectector. Based on the measured lifting velocity and compressive loads by traction of endless winder sheave the compressive load-angle of rotation history at the FCL was determined. According to the compressive load-angle of rotation time history total 230 FE analyses were performed with the interval of the angle of rotation of 15° we eventually obtained the fatigue stress spectrum at the FCL. These results were processed using the rainflow cycle counting and the Goodman equation. Finally the fatigue life of sheave was evaluated using the linear damage cumulative rule.

2014-01-01T23:59:59.000Z

293

Sequential separation of actinide elements from highly radioactive Hanford waste by ion exchange methods  

SciTech Connect (OSTI)

A simple, rapid method has been developed for the sequential separation of actinide elements from samples with high salt content such as these resulting from efforts to characterize Hanford storage tank waste. Actinide elements in 9M HC1 solution are introduced into an anion exchange column. U(VI), Np(IV) and Pu(IV) are retained on the column while Am(III) passes through. Plutonium is eluted first, reductively; after which neptunium and then uranium are eluted with mixtures of HC1 and HF. The Am(III) is purified by cation exchange in a nitric acid system. 14 refs., 2 tabs.

Maiti, T.C.; Kaye, J.H.; Kozelisky, A.E.

1991-04-01T23:59:59.000Z

294

An Adaptive Fast Multipole Higher Order Boundary Element Method for Power Frequency Electric Field of Substation  

Science Journals Connector (OSTI)

An adaptive fast multipole higher order boundary element method combining fast multipole (FM) with a higher order boundary element method is studied to solve the power frequency electric field (PFEF) of substations. In this new technique, the iterative equation solver GMRES is used in the FM, where matrix-vector multiplications are calculated using fast multipole expansions. The coefficients in the preconditioner for GMRES are stored and are used repeatedly in the direct evaluations of the near-field contributions. Then a 500kV outdoor substation is modeled and the PFEF of the substation is analyzed by the novel algorithm and other conventional methods. The results show that, in computational cost and the storages capability aspects, the algorithm proposed in this study has obvious advantages. It is suitable for the calculation of the large-scale PFEF in complex substations and the design of electromagnetic compatibility.

Zhang Zhan-Long; Deng Jun; Xiao Dong-Ping; He Wei; Tang Ju

2010-01-01T23:59:59.000Z

295

Matrix elements of the tight?binding method for lattices with D 14 4h symmetry (part 2)  

Science Journals Connector (OSTI)

We have evaluated the matrix elements of the Hamiltonian in the LCAO method for all the crystals with D 14 4h symmetry.

C. Jouanin; J. P. Albert; C. Gout; N. Daude

1975-01-01T23:59:59.000Z

296

Geomechanical Simulations of CO2 Storage Integrity using the Livermore Distinct Element Method  

SciTech Connect (OSTI)

Large-scale carbon capture and sequestration (CCS) projects involving annual injections of millions of tons of CO{sub 2} are a key infrastructural element needed to substantially reduce greenhouse gas emissions. The large rate and volume of injection will induce pressure and stress gradients within the formation that could activate existing fractures and faults, or drive new fractures through the caprock. We will present results of an ongoing investigation to identify conditions that will activate existing fractures/faults or make new fractures within the caprock using the Livermore Distinct Element Code (LDEC). LDEC is a multiphysics code, developed at LLNL, capable of simulating dynamic fracture of rock masses under a range of conditions. As part of a recent project, LDEC has been extended to consider fault activation and dynamic fracture of rock masses due to pressurization of the pore-space. We will present several demonstrations of LDEC functionality and applications of LDEC to CO{sub 2} injection scenarios including injection into an extensively fractured rockmass. These examples highlight the advantages of explicitly including the geomechanical response of each interface within the rockmass. We present results from our investigations of Teapot Dome using LDEC to study the potential for fault activation during injection. Using this approach, we built finite element models of the rock masses surrounding bounding faults and explicitly simulated the compression and shear on the fault interface. A CO{sub 2} injection source was introduced and the area of fault activation was predicted as a function of injection rate. This work presents an approach where the interactions of all locations on the fault are considered in response to specific injection scenarios. For example, with LDEC, as regions of the fault fail, the shear load is taken up elsewhere on the fault. The results of this study are consistent with previous studies of Teapot Dome and indicate significantly elevated pore pressures are required to activate the bounding faults, given the assumed in situ stress state on the faults.

Morris, J P; Johnson, S M; Friedmann, S J

2008-07-11T23:59:59.000Z

297

Geomechanical Simulations of Caprock Integrity Using the Livermore Distinict Element Method  

SciTech Connect (OSTI)

Large-scale carbon capture and sequestration (CCS) projects involving annual injections of millions of tons of CO2 are a key infrastructural element needed to substantially reduce greenhouse gas emissions. The large rate and volume of injection will induce pressure and stress gradients within the formation that could activate existing fractures and faults, or drive new fractures through the caprock. We will present results of an ongoing investigation to identify conditions that will activate existing fractures/faults or make new fractures within the caprock using the Livermore Distinct Element Code (LDEC). LDEC is a multiphysics code, developed at LLNL, capable of simulating dynamic fracture of rock masses under a range of conditions. As part of a recent project, LDEC has been extended to consider fault activation and dynamic fracture of rock masses due to pressurization of the pore-space. We will present several demonstrations of LDEC functionality and an application of LDEC to a CO2 injection scenario. We present results from our investigations of Teapot Dome using LDEC to study the potential for fault activation during injection. Using this approach, we built finite element models of the rock masses surrounding bounding faults and explicitly simulated the compression and shear on the fault interface. A CO2 injection source was introduced and the area of fault activation was predicted as a function of injection rate. This work presents an approach where the interactions of all locations on the fault are considered in response to specific injection scenarios. For example, with LDEC, as regions of the fault fail, the shear load is taken up elsewhere on the fault. The results of this study are consistent with previous studies of Teapot Dome and indicate significantly elevated pore pressures are required to activate the bounding faults, given the assumed in situ stress state on the faults.

Morris, J; Johnson, S; Friedmann, S J

2008-04-17T23:59:59.000Z

298

DYNA3D: A nonlinear, explicit, three-dimensional finite element code for solid and structural mechanics, User manual. Revision 1  

SciTech Connect (OSTI)

This report is the User Manual for the 1993 version of DYNA3D, and also serves as a User Guide. DYNA3D is a nonlinear, explicit, finite element code for analyzing the transient dynamic response of three-dimensional solids and structures. The code is fully vectorized and is available on several computer platforms. DYNA3D includes solid, shell, beam, and truss elements to allow maximum flexibility in modeling physical problems. Many material models are available to represent a wide range of material behavior, including elasticity, plasticity, composites, thermal effects, and rate dependence. In addition, DYNA3D has a sophisticated contact interface capability, including frictional sliding and single surface contact. Rigid materials provide added modeling flexibility. A material model driver with interactive graphics display is incorporated into DYNA3D to permit accurate modeling of complex material response based on experimental data. Along with the DYNA3D Example Problem Manual, this document provides the information necessary to apply DYNA3D to solve a wide range of engineering analysis problems.

Whirley, R.G.; Engelmann, B.E.

1993-11-01T23:59:59.000Z

299

Progressive Damage Analysis of Laminated Composite (PDALC)-A Computational Model Implemented in the NASA COMET Finite Element Code  

Science Journals Connector (OSTI)

A method for analysis of progressive failure in the Computational Structural Mechanics Testbed is presented in this report. The relationship employed in this analysis describes the matrix crack damage and fiber fracture via kinematics-based volume-averaged ...

Lo David C.; Coats Timothy W.; Harris Charles E.; Allen David H.

1996-11-01T23:59:59.000Z

300

A spectral-element discontinuous Galerkin lattice Boltzmann method for incompressible flows.  

SciTech Connect (OSTI)

We present a spectral-element discontinuous Galerkin lattice Boltzmann method for solving nearly incompressible flows. Decoupling the collision step from the streaming step offers numerical stability at high Reynolds numbers. In the streaming step, we employ high-order spectral-element discontinuous Galerkin discretizations using a tensor product basis of one-dimensional Lagrange interpolation polynomials based on Gauss-Lobatto-Legendre grids. Our scheme is cost-effective with a fully diagonal mass matrix, advancing time integration with the fourth-order Runge-Kutta method. We present a consistent treatment for imposing boundary conditions with a numerical flux in the discontinuous Galerkin approach. We show convergence studies for Couette flows and demonstrate two benchmark cases with lid-driven cavity flows for Re = 400-5000 and flows around an impulsively started cylinder for Re = 550-9500. Computational results are compared with those of other theoretical and computational work that used a multigrid method, a vortex method, and a spectral element model.

Min, M.; Lee, T.; Mathematics and Computer Science; City Univ. of New York

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Stability and Convergence of a Finite Volume Method for a Reaction-Diffusion system of  

E-Print Network [OSTI]

accounts for the dynamics of the trans-membrane ionic currents Iion and difference of potential u. It writes du dt = 2 · ( u) + Iion, (1) #12;Finite Volume and Electrocardiology 3 and can be obtained through an homogenization process [FRA 02]. The total ionic current Iion is controlled both by the trans

Pierre, Charles

302

An Upwind Finite-Difference Method for Total Variation–Based ...  

E-Print Network [OSTI]

standard approach, as first suggested in [28], is to regularize the BV seminorm and consider ..... The result applied to our (finite-dimensional) problem gives the following: if .... We did a series of experiments (a) to measure the effectiveness ..... plane by the minimizing total variation flow, Interfaces Free Bound., 7 (2005), pp.

2011-03-17T23:59:59.000Z

303

An adaptively refined phase-space element method for cosmological simulations and collisionless dynamics  

E-Print Network [OSTI]

Dark matter numerical simulations and the N-body method are essential for understanding how structure forms and evolves in the Universe. However, the discrete nature of N-body simulations can affect its accuracy when modelling collisionless systems. We introduce a new approach to simulate the gravitational evolution of cold collisionless fluids by solving the Vlasov-Poisson equations in terms of adaptively refineable "Lagrangian phase space elements". These geometrical elements are piecewise smooth maps between three-dimensional Lagrangian space and six-dimensional Eulerian phase space and approximate the continuum structure of the distribution function. They allow for dynamical adaptive splitting to follow the evolution even in regions of very strong mixing. We discuss various test problems which demonstrate the correctness and performance of our method. We show that it has several advantages compared to standard N-body algorithms by i) explicitly tracking the fine-grained distribution function, ii) naturall...

Hahn, Oliver

2015-01-01T23:59:59.000Z

304

Algebraic multigrid preconditioning within parallel finite-element solvers for 3-D electromagnetic modelling problems in geophysics  

Science Journals Connector (OSTI)

......These methods have low requirements for storage capacity, which is, in addition, fixed...of two half-spaces, which represent seawater (sigma0-=-3.3 S-m1) and sediments...of two half-spaces, which represent seawater (sigma0-=-3.3 S-m1) and sediments......

Jelena Koldan; Vladimir Puzyrev; Josep de la Puente; Guillaume Houzeaux; José María Cela

2014-01-01T23:59:59.000Z

305

Stein's method, heat kernel, and traces of powers of elements of compact Lie groups  

E-Print Network [OSTI]

Combining Stein's method with heat kernel techniques, we show that the trace of the jth power of an element of U(n,C), USp(n,C) or SO(n,R) has a normal limit with error term of order j/n. In contrast to previous works, here j may be growing with n. The technique should prove useful in the study of the value distribution of approximate eigenfunctions of Laplacians.

Jason Fulman

2010-05-07T23:59:59.000Z

306

Parallel, Multigrid Finite Element Simulator for Fractured/Faulted and Other Complex Reservoirs based on Common Component Architecture (CCA)  

SciTech Connect (OSTI)

Black-oil, compositional and thermal simulators have been developed to address different physical processes in reservoir simulation. A number of different types of discretization methods have also been proposed to address issues related to representing the complex reservoir geometry. These methods are more significant for fractured reservoirs where the geometry can be particularly challenging. In this project, a general modular framework for reservoir simulation was developed, wherein the physical models were efficiently decoupled from the discretization methods. This made it possible to couple any discretization method with different physical models. Oil characterization methods are becoming increasingly sophisticated, and it is possible to construct geologically constrained models of faulted/fractured reservoirs. Discrete Fracture Network (DFN) simulation provides the option of performing multiphase calculations on spatially explicit, geologically feasible fracture sets. Multiphase DFN simulations of and sensitivity studies on a wide variety of fracture networks created using fracture creation/simulation programs was undertaken in the first part of this project. This involved creating interfaces to seamlessly convert the fracture characterization information into simulator input, grid the complex geometry, perform the simulations, and analyze and visualize results. Benchmarking and comparison with conventional simulators was also a component of this work. After demonstration of the fact that multiphase simulations can be carried out on complex fracture networks, quantitative effects of the heterogeneity of fracture properties were evaluated. Reservoirs are populated with fractures of several different scales and properties. A multiscale fracture modeling study was undertaken and the effects of heterogeneity and storage on water displacement dynamics in fractured basements were investigated. In gravity-dominated systems, more oil could be recovered at a given pore volume of injection at lower rates. However, if oil production can be continued at high water cuts, the discounted cumulative production usually favors higher production rates. The workflow developed during the project was also used to perform multiphase simulations in heterogeneous, fracture-matrix systems. Compositional and thermal-compositional simulators were developed for fractured reservoirs using the generalized framework. The thermal-compositional simulator was based on a novel 'equation-alignment' approach that helped choose the correct variables to solve depending on the number of phases present and the prescribed component partitioning. The simulators were used in steamflooding and in insitu combustion applications. The framework was constructed to be inherently parallel. The partitioning routines employed in the framework allowed generalized partitioning on highly complex fractured reservoirs and in instances when wells (incorporated in these models as line sources) were divided between two or more processors.

Milind Deo; Chung-Kan Huang; Huabing Wang

2008-08-31T23:59:59.000Z

307

A Freestream-Preserving High-Order Finite-Volume Method for Mapped Grids with Adaptive-Mesh Refinement  

SciTech Connect (OSTI)

A fourth-order accurate finite-volume method is presented for solving time-dependent hyperbolic systems of conservation laws on mapped grids that are adaptively refined in space and time. Novel considerations for formulating the semi-discrete system of equations in computational space combined with detailed mechanisms for accommodating the adapting grids ensure that conservation is maintained and that the divergence of a constant vector field is always zero (freestream-preservation property). Advancement in time is achieved with a fourth-order Runge-Kutta method.

Guzik, S; McCorquodale, P; Colella, P

2011-12-16T23:59:59.000Z

308

Inverse transonic wing design using finite-volume methods in curvilinear coordinates  

E-Print Network [OSTI]

&U)i j k = (Ui~h j~b k+ Ui+Q j Q k + Ui Q j+Q k+ Ui h j h k)/4 etc. When extended to the other flux components and to averaging over cube surfaces in three dimensions, the numerical potential equation is of the form: @&f6'(PhU) + @[f6?(PhV) + Pf 6f...(PhW) = 0 Figure 2. Finite-Volume Cell Location To find the flux quantities phU, phV, and phW at the finite volume cell vertices (i. e. points a, b, c, and d for the two dimensional case), it is necessary to evaluate Equations (2) through (4...

Gally, Thomas Anthony

2012-06-07T23:59:59.000Z

309

Optical sensing elements for nitrogen dioxide (NO.sub.2) gas detection, a sol-gel method for making the sensing elements and fiber optic sensors incorporating nitrogen dioxide gas optical sensing elements  

DOE Patents [OSTI]

A sensing element, a method of making a sensing element, and a fiber optic sensor incorporating the sensing element are described. The sensor can be used for the quantitative detection of NO.sub.2 in a mixture of gases. The sensing element can be made by incorporating a diazotizing reagent which reacts with nitrous ions to produce a diazo compound and a coupling reagent which couples with the diazo compound to produce an azo dye into a sol and allowing the sol to form an optically transparent gel. The sensing element changes color in the presence of NO.sub.2 gas. The temporal response of the absorption spectrum at various NO.sub.2 concentrations has also been recorded and analyzed. Sensors having different design configurations are described. The sensing element can detect NO.sub.2 gas at levels of parts per billion.

Mechery, Shelly John (Mississippi State, MS); Singh, Jagdish P. (Starkville, MS)

2007-07-03T23:59:59.000Z

310

Failure analysis of reinforced polyurethane foam-based LNG insulation structure using damage-coupled finite element analysis  

Science Journals Connector (OSTI)

Abstract The primary aim of this study was to develop a unified anisotropic elasto-viscoplastic-damage model that describes the material nonlinear behavior and damage/crack growth of a reinforced polyurethane foam-based liquefied natural gas carrier insulation system. A Bodner–Partom unified elasto-viscoplastic model independent of the yield surface and loading history was expanded to an anisotropic unified model. To predict the damage growth and the crack initiation/growth of reinforced polyurethane foam, a Bodner–Chan damage model was applied to the proposed unified elasto-viscoplastic-damage model. The developed mechanical model was implicitly formulated and implemented into an ABAQUS user-defined material subroutine. To validate the proposed numerical method, the simulation results were compared with the results of a series of static uniaxial tests and dynamic cyclic tests conducted on the reinforced polyurethane foam and the liquefied natural gas carrier insulation system, respectively.

Chi-Seung Lee; Jae-Myung Lee

2014-01-01T23:59:59.000Z

311

Spectral distribution method for neutrinoless double-beta decay nuclear transition matrix elements: Binary correlation results  

E-Print Network [OSTI]

Neutrinoless double-beta decay nuclear transition matrix elements are generated by an effective two-body transition operator and it consists of Gamow-Teller like and Fermi like (also tensor) operators. Spectral distribution method for the corresponding transition strengths (squares of the transition matrix elements) involves convolution of the transition strength density generated by the non-interacting particle part of the Hamiltonian with a spreading function generated by the two-body part of the Hamiltonian. Extending the binary correlation theory for spinless embedded $k$-body ensembles to ensembles with proton-neutron degrees of freedom, we establish that the spreading function is a bivariate Gaussian for transition operators $\\co(k_\\co)$ that change $k_\\co$ number of neutrons to $k_\\co$ number of protons. Towards this end, we have derived the formulas for the fourth-order cumulants of the spreading function and calculated their values for some heavy nuclei; they are found to vary from $\\sim -0.4$ to -0.1. Also for nuclei from $^{76}$Ge to $^{238}$U, the bivariate correlation coefficient is found to vary from $\\sim 0.6 - 0.8$ and these values can be used as a starting point for calculating nuclear transition matrix elements using the spectral distribution method.

Manan Vyas; V. K. B. Kota

2011-06-02T23:59:59.000Z

312

Coupled numerical approach combining finite volume and lattice Boltzmann methods for multi-scale multi-physicochemical processes  

SciTech Connect (OSTI)

A coupled (hybrid) simulation strategy spatially combining the finite volume method (FVM) and the lattice Boltzmann method (LBM), called CFVLBM, is developed to simulate coupled multi-scale multi-physicochemical processes. In the CFVLBM, computational domain of multi-scale problems is divided into two sub-domains, i.e., an open, free fluid region and a region filled with porous materials. The FVM and LBM are used for these two regions, respectively, with information exchanged at the interface between the two sub-domains. A general reconstruction operator (RO) is proposed to derive the distribution functions in the LBM from the corresponding macro scalar, the governing equation of which obeys the convection–diffusion equation. The CFVLBM and the RO are validated in several typical physicochemical problems and then are applied to simulate complex multi-scale coupled fluid flow, heat transfer, mass transport, and chemical reaction in a wall-coated micro reactor. The maximum ratio of the grid size between the FVM and LBM regions is explored and discussed. -- Highlights: •A coupled simulation strategy for simulating multi-scale phenomena is developed. •Finite volume method and lattice Boltzmann method are coupled. •A reconstruction operator is derived to transfer information at the sub-domains interface. •Coupled multi-scale multiple physicochemical processes in micro reactor are simulated. •Techniques to save computational resources and improve the efficiency are discussed.

Chen, Li; He, Ya-Ling [Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)] [Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China); Kang, Qinjun [Computational Earth Science Group (EES-16), Los Alamos National Laboratory, Los Alamos, NM (United States)] [Computational Earth Science Group (EES-16), Los Alamos National Laboratory, Los Alamos, NM (United States); Tao, Wen-Quan, E-mail: wqtao@mail.xjtu.edu.cn [Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)] [Key Laboratory of Thermo-Fluid Science and Engineering of MOE, School of Energy and Power Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi 710049 (China)

2013-12-15T23:59:59.000Z

313

Transient analysis of printed lines using finite-difference time-domain method  

SciTech Connect (OSTI)

Comprehensive studies of ultra-wideband pulses and electromagnetic coupling on printed coupled lines have been performed using full-wave 3D finite-difference time-domain analysis. Effects of unequal phase velocities of coupled modes, coupling between line traces, and the frequency dispersion on the waveform fidelity and crosstalk have been investigated in detail. To discriminate the contributions of different mechanisms into pulse evolution, single and coupled microstrip lines without (?r?=?1) and with (?r?>?1) dielectric substrates have been examined. To consistently compare the performance of the coupled lines with substrates of different permittivities and transients of different characteristic times, a generic metric similar to the electrical wavelength has been introduced. The features of pulse propagation on coupled lines with layered and pedestal substrates and on the irregular traces have been explored. Physical interpretations of the simulation results are discussed in the paper.

Ahmed, Shahid [JLAB

2013-01-01T23:59:59.000Z

314

Finite-orbit method for dynamic analysis of mirror fusion systems  

SciTech Connect (OSTI)

A model (FOREMD) is described which treats plasma buildup in small mirror fusion devices where finite gyroradius effects are important to the dynamic evolution of the density and energy profiles. An energy-dependent group technique is employed, but unlike conventional point-kinetic diffusion models, the local density is calculated by a summing over orbits passing through the volume of interest. This treatment is particularly important during buildup via neutral beam injection where charge-exchange losses near the surface affect the inner-volume density distribution through loss of large orbit ions. As an example of the use of FOREMD, buildup processes in two experimental devices (2X-IIB and TMX) are examined.

Campbell, M.M.; Miley, G.H.

1981-01-01T23:59:59.000Z

315

Boundary elements method for microfluidic two-phase flows in shallow channels  

E-Print Network [OSTI]

In the following work we apply the boundary element method to two-phase flows in shallow microchannels, where one phase is dispersed and does not wet the channel walls. These kinds of flows are often encountered in microfluidic Lab-on-a-Chip devices and characterized by low Reynolds and low capillary numbers. Assuming that these channels are homogeneous in height and have a large aspect ratio, we use depth-averaged equations to describe these two-phase flows using the Brinkman equation, which constitutes a refinement of Darcy's law. These partial differential equations are discretized and solved numerically using the boundary element method, where a stabilization scheme is applied to the surface tension terms, allowing for a less restrictive time step at low capillary numbers. The convergence of the numerical algorithm is checked against a static analytical solution and on a dynamic test case. Finally the algorithm is applied to the non-linear development of the Saffman-Taylor instability and compared to expe...

Nagel, Mathias

2014-01-01T23:59:59.000Z

316

Method and an apparatus for non-invasively determining the quantity of an element in a body organ  

DOE Patents [OSTI]

An apparatus and a method for determining in a body organ the amount of an element with the aid of a gaseous gamma ray source, where the element and the source are paired in predetermined pairs, and with the aid of at least one detector selected from the group consisting of Ge(Li) and NaI(Tl). Gamma rays are directed towards the organ, thereby resonantly scattering the gamma rays from nuclei of the element in the organ; the intensity of the gamma rays is detected by the detector; and the amount of the element in the organ is then substantially proportional to the detected intensity of the gamma rays.

Vartsky, D.; Ellis, K.J.; Cohn, S.H.

1980-06-27T23:59:59.000Z

317

A bridge-functional-based classical mapping method for predicting the correlation functions of uniform electron gases at finite temperature  

SciTech Connect (OSTI)

Efficient and accurate prediction of the correlation functions of uniform electron gases is of great importance for both practical and theoretical applications. This paper presents a bridge-functional-based classical mapping method for calculating the correlation functions of uniform spin-unpolarized electron gases at finite temperature. The bridge functional is formulated by following Rosenfeld's universality ansatz in combination with the modified fundamental measure theory. The theoretical predictions are in good agreement with recent quantum Monte Carlo results but with negligible computational cost, and the accuracy is better than a previous attempt based on the hypernetted-chain approximation. We find that the classical mapping method is most accurate if the effective mass of electrons increases as the density falls.

Liu, Yu; Wu, Jianzhong, E-mail: jwu@engr.ucr.edu [Department of Chemical and Environmental Engineering and Department of Mathematics, University of California, Riverside, California 92521 (United States)] [Department of Chemical and Environmental Engineering and Department of Mathematics, University of California, Riverside, California 92521 (United States)

2014-02-28T23:59:59.000Z

318

Top Quark Mass Measurement in the Lepton plus Jets Channel Using a Modified Matrix Element Method  

SciTech Connect (OSTI)

The authors report a measurement of the top quark mass, m{sub t}, obtained from p{bar p} collisions at {radical}s = 1.96 TeV at the Fermilab Tevatron using the CDF II detector. They analyze a sample corresponding to an integrated luminosity of 1.9 rfb{sup -1}. They select events with an electron or muon, large missing transverse energy, and exactly four high-energy jets in the central region of the detector, at least one of which is tagged as coming from a b quark. They calculate a signal likelihood using a matrix element integration method, where the matrix element is modified by using effective propagators to take into account assumptions on event kinematics. The event likelihood is a function of m{sub t} and a parameter JES that determines in situ the calibration of the jet energies. They use a neural network discriminant to distinguish signal from background events. They also apply a cut on the peak value of each event likelihood curve to reduce the contribution of background and badly reconstructed events. Using the 318 events that pass all selection criteria, they find m{sub t} = 172.7 {+-} 1.8 (stat. + JES) {+-} 1.2(syst.) GeV/c{sup 2}.

Aaltonen, T.; /Helsinki Inst. of Phys.; Adelman, J.; /Chicago U., EFI; Akimoto, T.; /Tsukuba U.; Alvarez Gonzalez, B.; /CSIC, Catalunya; Amerio, S.; /INFN, Padua; Amidei, D.; /Michigan U.; Anastassov, A.; /Northwestern U.; Annovi, A.; /Frascati; Antos, J.; /Comenius U.; Apollinari, G.; /Fermilab; Apresyan, A.; /Purdue U. /Waseda U.

2008-12-01T23:59:59.000Z

319

A Pin Power Reconstruction Method for CANDU Reactor Cores Based on Coarse-Mesh Finite Difference Calculations  

SciTech Connect (OSTI)

A reconstruction method has been developed for recovering pin powers from Canada deuterium uranium (CANDU) reactor core calculations performed with a coarse-mesh finite difference diffusion approximation and single-assembly lattice calculations. The homogeneous intranodal distributions of group fluxes are efficiently computed using polynomial shapes constrained to satisfy the nodal information approximated from the node-average fluxes. The group fluxes of individual fuel pins in a heterogeneous fuel bundle are determined using these homogeneous intranodal flux distributions and the form functions obtained from the single-assembly lattice calculations. The pin powers are obtained using these pin fluxes and the pin power cross sections generated by the single-assembly lattice calculation. The accuracy of the reconstruction schemes has been estimated by performing benchmark calculations for partial core representation of a natural uranium CANDU reactor. The results indicate that the reconstruction schemes are quite accurate, yielding maximum pin power errors of less than {approx}3%. The main contribution to the reconstruction error is made by the errors in the node-average fluxes obtained from the coarse-mesh finite difference diffusion calculation; the errors due to the reconstruction schemes are <1%.

Lee, Hyung-Seok [Chosun University (Korea, Republic of); Yang, Won Sik [Chosun University (Korea, Republic of); Na, Man Gyun [Chosun University (Korea, Republic of); Choi, Hangbok [Korea Atomic Energy Research Institute (Korea, Republic of)

2000-04-15T23:59:59.000Z

320

A high-order finite-volume method for hyperbolic conservation laws on locally-refined grids  

SciTech Connect (OSTI)

We present a fourth-order accurate finite-volume method for solving time-dependent hyperbolic systems of conservation laws on Cartesian grids with multiple levels of refinement. The underlying method is a generalization of that in [5] to nonlinear systems, and is based on using fourth-order accurate quadratures for computing fluxes on faces, combined with fourth-order accurate Runge?Kutta discretization in time. To interpolate boundary conditions at refinement boundaries, we interpolate in time in a manner consistent with the individual stages of the Runge-Kutta method, and interpolate in space by solving a least-squares problem over a neighborhood of each target cell for the coefficients of a cubic polynomial. The method also uses a variation on the extremum-preserving limiter in [8], as well as slope flattening and a fourth-order accurate artificial viscosity for strong shocks. We show that the resulting method is fourth-order accurate for smooth solutions, and is robust in the presence of complex combinations of shocks and smooth flows.

McCorquodale, Peter; Colella, Phillip

2011-01-28T23:59:59.000Z

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


321

A Second Order Thermal and Momentum Immersed Boundary Method for Conjugate Heat Transfer in a Cartesian Finite Volume Solver  

E-Print Network [OSTI]

A conjugate heat transfer (CHT) immersed boundary (IB and CHTIB) method is developed for use with laminar and turbulent flows with low to moderate Reynolds numbers. The method is validated with the canonical flow of two co-annular rotating cylinders at $Re=50$ which shows second order accuracy of the $L_{2}$ and $L_{\\infty}$ error norms of the temperature field over a wide rage of solid to fluid thermal conductivities, $\\kappa_{s}/\\kappa_{f} = \\left(9-100\\right)$. To evaluate the CHTIBM with turbulent flow a fully developed, heated, turbulent channel $\\left(Re_{u_{\\tau}}=150\\text{ and } \\kappa_{s}/\\kappa_{f}=4 \\right)$ is used which shows near perfect correlation to previous direct numerical simulation (DNS) results. The CHTIB method is paired with a momentum IB method (IBM), both of which use a level set field to define the wetted boundaries of the fluid/solid interfaces and are applied to the flow solver implicitly with rescaling of the difference operators of the finite volume (FV) method (FVM).

Crocker, Ryan; Desjardins, Olivier

2014-01-01T23:59:59.000Z

322

A graphical preprocessing interface for non-conforming spectral element solvers  

E-Print Network [OSTI]

Page 1 Left: Discretization of a square using 50?50 1 st order elements by FEM. Right: Discretizations of a square using 50 th -order single domain with SM... representative numerical technique of this kind is the Finite Element Method (FEM) [2]. It uses small finite number of elements with low order approximation functions (Fig. 1 left). When engineering models have complex geometry, FEM discretizes the geometry (e...

Kim, Bo Hung

2009-06-02T23:59:59.000Z

323

Solutions of turbulent backward-facing step flow with heat transfer using the finite volume method  

SciTech Connect (OSTI)

The heated turbulent flow over a backward-facing step is numerically solved using the commercial computational fluid dynamics program FLUENT. The methods used here consist of the default power-law upwinding scheme, default multigrid equation solution method and a standard k-{var_epsilon} turbulence model with wall functions. A total of four separate cases are reported. The four cases consist of combinations of partially and fully developed flow at the inlet with uniform or developed temperature profiles. Three mesh refinements are reported for each flow.

Horstman, R.H. [Boeing Commercial Airplane, Seattle, WA (United States). Environmental Control Systems R& D; Cochran, R.J. [Sandia National Labs., Albuquerque, NM (United States); Emergy, A.F. [Univ. of Washington, Seattle, WA (United States). Dept. of Mechanical Engineering

1995-12-31T23:59:59.000Z

324

Calculation of large ion densities under HVdc transmission lines by the finite difference method  

SciTech Connect (OSTI)

A calculation method for large ion densities (charged aerosols) under HVdc transmission lines was developed considering both the charging mechanism of aerosols by small ions and the drifting process by wind. Large ion densities calculated by this method agreed well with the ones measured under the Shiobara HVdc test line on the lateral profiles at ground level up to about 70m downwind from the line. Measured values decreased more quickly than calculated ones farther downwind from the line. Considering the effect of point discharge from ground cover (earth corona) improved the agreement in the farther downwind region.

Suda, Tomotaka; Sunaga, Yoshitaka [Central Research Institute of Electrical Power Industry, Komae, Tokyo (Japan)] [Central Research Institute of Electrical Power Industry, Komae, Tokyo (Japan)

1995-10-01T23:59:59.000Z

325

A posteriori error estimates for mixed finite element and finite volume methods for problems coupled through a boundary with nonmatching grids  

Science Journals Connector (OSTI)

......often rationalized using a combination of ad hoc formal stability and/or accuracy arguments combined with high performance computing expe- diences. Moreover, in the situation in which legacy codes are used to solve either component, there......

T. Arbogast; D. Estep; B. Sheehan; S. Tavener

2014-10-01T23:59:59.000Z

326

Investigations of ?-helix??-sheet transition pathways in a miniprotein using the finite-temperature string method  

SciTech Connect (OSTI)

A parallel implementation of the finite-temperature string method is described, which takes into account the invariance of coordinates with respect to rigid-body motions. The method is applied to the complex ?-helix??-sheet transition in a ?-hairpin miniprotein in implicit solvent, which exhibits much of the complexity of conformational changes in proteins. Two transition paths are considered, one derived from a linear interpolant between the endpoint structures and the other derived from a targeted dynamics simulation. Two methods for computing the conformational free energy (FE) along the string are compared, a restrained method, and a tessellation method introduced by E. Vanden-Eijnden and M. Venturoli [J. Chem. Phys. 130, 194103 (2009)]. It is found that obtaining meaningful free energy profiles using the present atom-based coordinates requires restricting sampling to a vicinity of the converged path, where the hyperplanar approximation to the isocommittor surface is sufficiently accurate. This sampling restriction can be easily achieved using restraints or constraints. The endpoint FE differences computed from the FE profiles are validated by comparison with previous calculations using a path-independent confinement method. The FE profiles are decomposed into the enthalpic and entropic contributions, and it is shown that the entropy difference contribution can be as large as 10 kcal/mol for intermediate regions along the path, compared to 15–20 kcal/mol for the enthalpy contribution. This result demonstrates that enthalpic barriers for transitions are offset by entropic contributions arising from the existence of different paths across a barrier. The possibility of using systematically coarse-grained representations of amino acids, in the spirit of multiple interaction site residue models, is proposed as a means to avoid ad hoc sampling restrictions to narrow transition tubes.

Ovchinnikov, Victor, E-mail: ovchinnv@georgetown.edu [Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States)] [Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States); Karplus, Martin, E-mail: marci@tammy.harvard.edu [Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States) [Department of Chemistry and Chemical Biology, Harvard University, Cambridge, Massachusetts 02138 (United States); Laboratoire de Chimie Biophysique, ISIS, Université de Strasbourg, 67000 Strasbourg (France)

2014-05-07T23:59:59.000Z

327

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

E-Print Network [OSTI]

diffusion schemes. xuthus, a 2-D AMR transport code implementing these findings, has been developed for unstructured triangular meshes....

Wang, Yaqi

2010-01-16T23:59:59.000Z

328

Numerical Modeling of Hydraulic Fracture Propagation Using Thermo-hydro-mechanical Analysis with Brittle Damage Model by Finite Element Method  

E-Print Network [OSTI]

Better understanding and control of crack growth direction during hydraulic fracturing are essential for enhancing productivity of geothermal and petroleum reservoirs. Structural analysis of fracture propagation and impact on fluid flow is a...

Min, Kyoung

2013-07-16T23:59:59.000Z

329

A high-order, adaptive, discontinuous Galerkin finite element method for the Reynolds-Averaged Navier-Stokes equations  

E-Print Network [OSTI]

This thesis presents high-order, discontinuous Galerkin (DG) discretizations of the Reynolds-Averaged Navier-Stokes (RANS) equations and an output-based error estimation and mesh adaptation algorithm for these discretizations. ...

Oliver, Todd A., 1980-

2008-01-01T23:59:59.000Z

330

Shock capturing with PDE-based artificial viscosity for an adaptive, higher-order discontinuous Galerkin finite element method  

E-Print Network [OSTI]

The accurate simulation of supersonic and hypersonic flows is well suited to higher-order (p > 1), adaptive computational fluid dynamics (CFD). Since these cases involve flow velocities greater than the speed of sound, an ...

Barter, Garrett E. (Garrett Ehud), 1979-

2008-01-01T23:59:59.000Z

331

Shock Capturing with PDE-Based Artificial Viscosity for an Adaptive, Higher-Order Discontinuous Galerkin Finite Element Method  

E-Print Network [OSTI]

The accurate simulation of supersonic and hypersonic flows is well suited to higher-order (p > 1), adaptive computational fluid dynamics (CFD). Since these cases involve flow velocities greater than the speed of sound, an ...

Barter, Garrett Ehud

332

Supporting material for the paper 'Analysis of an interface stabilised finite element method: The advection-diffusion-reaction equation'  

E-Print Network [OSTI]

compilation of the form parameters.optimize = True # Define boundary of domain class Boundary(SubDomain): def inside(self, x, on_boundary): return on_boundary def solve(mesh, order, model): # Advective velocity V_b = VectorFunctionSpace(mesh, "CG", order+6) b... , V: Constant(V.mesh(), (4.0/5.0, 3.0/5.0)) tmp0 = "(cos((pi*(1+x[0])*(1+x[1])*(1+x[1])/8))*pi*(1+x[1])*(1+x[1])/8)" tmp1 = "(cos((pi*(1+x[0])*(1+x[1])*(1+x[1])/8))*2*pi*(1+x[0])*(1+x[1])/8)" source = "(4.0/5.0)*tmp0 + (3.0/5.0)*tmp1 + 1 + sin((pi*(1+x...

Wells, G N

2009-10-28T23:59:59.000Z

333

International Conference on Extended Finite Element Methods Recent Developments and Applications T.P. Fries and A. Zilian (Eds)  

E-Print Network [OSTI]

XFEM 2009 T.P. Fries and A. Zilian (Eds) c RWTH Aachen, Germany, 2009 A SYSTEMATIC STUDY OF DIFFERENT) with standard FE shape functions NFEM i . I is the set of all nodes in the domain. We adopt an iso- parametric

334

Proper orthogonal decomposition approach and error estimation of mixed finite element methods for the tropical Pacific Ocean  

E-Print Network [OSTI]

for the tropical Pacific Ocean reduced gravity model Zhendong Luo a , Jiang Zhu b , Ruiwen Wang b , I.M. Navon c Available online 8 May 2007 Abstract In this paper, the tropical Pacific Ocean reduced gravity model and the insufficient knowledge of air­sea exchange processes. The tropical Pacific Ocean reduced gravity model

Navon, Michael

335

An iterative finite element time-domain method for simulating three-dimensional electromagnetic diffusion in earth  

E-Print Network [OSTI]

of an axially symmetric earth for vertical magnetic dipoleDevelopment Grants from Earth Sciences Division. Editor Dr.electromagnetic diffusion in earth Evan Schankee Um, 1 Jerry

Um, E.S.

2013-01-01T23:59:59.000Z

336

Study on small-strain behaviours of methane hydrate sandy sediments using discrete element method  

SciTech Connect (OSTI)

Methane hydrate bearing soil has attracted increasing interest as a potential energy resource where methane gas can be extracted from dissociating hydrate-bearing sediments. Seismic testing techniques have been applied extensively and in various ways, to detect the presence of hydrates, due to the fact that hydrates increase the stiffness of hydrate-bearing sediments. With the recognition of the limitations of laboratory and field tests, wave propagation modelling using Discrete Element Method (DEM) was conducted in this study in order to provide some particle-scale insights on the hydrate-bearing sandy sediment models with pore-filling and cementation hydrate distributions. The relationship between shear wave velocity and hydrate saturation was established by both DEM simulations and analytical solutions. Obvious differences were observed in the dependence of wave velocity on hydrate saturation for these two cases. From the shear wave velocity measurement and particle-scale analysis, it was found that the small-strain mechanical properties of hydrate-bearing sandy sediments are governed by both the hydrate distribution patterns and hydrate saturation.

Yu Yanxin; Cheng Yipik [Department of Civil, Environmental and Geomatic Engineering, University College London (UCL), Gower Street, London, WC1E 6BT (United Kingdom); Xu Xiaomin; Soga, Kenichi [Geotechnical and Environmental Research Group, Department of Engineering, University of Cambridge, Trumpington Street, Cambridge, CB2 1PZ (United Kingdom)

2013-06-18T23:59:59.000Z

337

Method And Apparatus For Coupling Optical Elements To Optoelectronic Devices For Manufacturing Optical Transceiver Modules  

DOE Patents [OSTI]

A process is provided for aligning and connecting at least one optical fiber to at least one optoelectronic device so as to couple light between at least one optical fiber and at least one optoelectronic device. One embodiment of this process comprises the following steps: (1) holding at least one optical element close to at least one optoelectronic device, at least one optical element having at least a first end; (2) aligning at least one optical element with at least one optoelectronic device; (3) depositing a first non-opaque material on a first end of at least one optoelectronic device; and (4) bringing the first end of at least one optical element proximate to the first end of at least one optoelectronic device in such a manner that the first non-opaque material contacts the first end of at least one optoelectronic device and the first end of at least one optical element. The optical element may be an optical fiber, and the optoelectronic device may be a vertical cavity surface emitting laser. The first non-opaque material may be a UV optical adhesive that provides an optical path and mechanical stability. In another embodiment of the alignment process, the first end of at least one optical element is brought proximate to the first end of at least one optoelectronic device in such a manner that an interstitial space exists between the first end of at least one optoelectronic device and the first end of at least one optical element.

Anderson, Gene R. (Albuquerque, NM); Armendariz, Marcelino G. (Albuquerque, NM); Bryan, Robert P. (Albuquerque, NM); Carson, Richard F. (Albuquerque, NM); Chu, Dahwey (Albuquerque, NM); Duckett, III, Edwin B. (Albuquerque, NM); Giunta, Rachel Knudsen (Albuquerque, NM); Mitchell, Robert T. (Albuquerque, NM); McCormick, Frederick B. (Albuquerque, NM); Peterson, David W. (Sandia Park, NM); Rising, Merideth A. (Santa Fe, NM); Reber, Cathleen A. (Corrales, NM); Reysen, Bill H. (Lafayette, CO)

2005-06-14T23:59:59.000Z

338

GOMA 6.0 : a full-Newton finite element program for free and moving boundary problems with coupled fluid/solid momentum, energy, mass, and chemical species transport : user%3CU%2B2019%3Es guide.  

SciTech Connect (OSTI)

Goma 6.0 is a finite element program which excels in analyses of multiphysical processes, particularly those involving the major branches of mechanics (viz. fluid/solid mechanics, energy transport and chemical species transport). Goma is based on a full-Newton-coupled algorithm which allows for simultaneous solution of the governing principles, making the code ideally suited for problems involving closely coupled bulk mechanics and interfacial phenomena. Example applications include, but are not limited to, coating and polymer processing flows, super-alloy processing, welding/soldering, electrochemical processes, and solid-network or solution film drying. This document serves as a user's guide and reference.

Schunk, Peter Randall; Rao, Rekha Ranjana; Chen, Ken Shuang; Labreche, Duane A.; Sun, Amy Cha-Tien; Hopkins, Matthew Morgan; Moffat, Harry K.; Roach, Robert Allen; Hopkins, Polly L.; Notz, Patrick K.; Roberts, Scott Alan; Sackinger, Philip A.; Subia, Samuel Ramirez; Wilkes, Edward Dean; Baer, Thomas A.; Noble, David R.; Secor, Robert B. [3M Engineering Systems and Technology, St. Paul, MN] [3M Engineering Systems and Technology, St. Paul, MN

2013-07-01T23:59:59.000Z

339

Finite-size lattice method and the roughening transition Service de Physique Thorique, CEN Saclay, BP n 2, 91190 Gif sur Yvette, France  

E-Print Network [OSTI]

L-275 Finite-size lattice method and the roughening transition J. M. Luck Service de Physique'ordre infini, ce que pré- voient des arguments d'universalité. Abstract. 2014 The roughening transition. - It has been shown that the roughening transition, which was introduced in solid state physics, also plays

Boyer, Edmond

340

A few new (?) facts about infinite elements  

E-Print Network [OSTI]

Keywords: Helmholtz equation; Infinite element; hp finite elements; Echo Area. 1. .... ¼ g :¼ ? ouinc on . ?2.1?. The Sommerfeld radiation condition represents a ...

2006-04-24T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Apparatus and method for heterodyne-generated two-dimensional detector array using a single element detector  

DOE Patents [OSTI]

Apparatus and method for heterodyne-generated, two-dimensional detector array using a single detector. Synthetic-array heterodyne detection, permits a single-element optical detector to behave as though it were divided into an array of separate heterodyne detector elements. A fifteen-element synthetic array has successfully been experimentally realized on a single-element detector, permitting all of the array elements to be read out continuously and in parallel from one electrical connection. A CO.sub.2 laser and a single-element HgCdTe photodiode are employed. A different heterodyne local oscillator frequency is incident upon the spatially resolvable regions of the detector surface. Thus, different regions are mapped to different heterodyne beat frequencies. One can determine where the photons were incident on the detector surface even though a single electrical connection to the detector is used. This also prevents the destructive interference that occurs when multiple speckles are imaged (similar to spatial diversity), In coherent LIDAR this permits a larger field of view. An acoustooptic modulator generates the local oscillator frequencies and can achieve adequate spatial separation of optical frequencies of the order of a megahertz apart.

Strauss, Charlie E. (Santa Fe, NM)

1997-01-01T23:59:59.000Z

342

Apparatus and method for heterodyne-generated two-dimensional detector array using a single element detector  

DOE Patents [OSTI]

Apparatus and method are disclosed for heterodyne-generated, two-dimensional detector array using a single detector. Synthetic-array heterodyne detection, permits a single-element optical detector to behave as though it were divided into an array of separate heterodyne detector elements. A fifteen-element synthetic array has successfully been experimentally realized on a single-element detector, permitting all of the array elements to be read out continuously and in parallel from one electrical connection. A CO{sub 2} laser and a single-element HgCdTe photodiode are employed. A different heterodyne local oscillator frequency is incident upon the spatially resolvable regions of the detector surface. Thus, different regions are mapped to different heterodyne beat frequencies. One can determine where the photons were incident on the detector surface even though a single electrical connection to the detector is used. This also prevents the destructive interference that occurs when multiple speckles are imaged (similar to spatial diversity), In coherent LIDAR this permits a larger field of view. An acoustooptic modulator generates the local oscillator frequencies and can achieve adequate spatial separation of optical frequencies of the order of a megahertz apart. 4 figs.

Strauss, C.E.

1997-11-18T23:59:59.000Z

343

Prediction of potential and current density distribution using the boundary element method  

E-Print Network [OSTI]

boundary. 12 7. Discontinuous 2D boundary elements in intrinsic coordinate system. . . . . 25 8. Discontinuous 3D linear (boundary) element (a) global coordinates (b) intrinsic coordinates. 30 9. A simple galvanic corrosion couple (potential field... in two dimensions). . . 35 10. Potential distribution along the surface of the electrodes (i. e. , at yW). . . . 38 11. A simple problem of a cube (potential field in three dimensions). . . , . . . 41 12. Corrosion cell (a) perspective (b) cross...

Pakalapati, Surya Narayana Raju

1992-01-01T23:59:59.000Z

344

On the better performance of the coarse-mesh finite-difference method for CANDU-type reactors  

Science Journals Connector (OSTI)

Recent assessment results indicate that the coarse-mesh finite-difference method (FDM) gives consistently smaller percent differences in channel powers than the fine-mesh FDM when compared to the reference MCNP solution for CANDU-type reactors. However, there is an impression that the fine-mesh FDM should always give more accurate results than the coarse-mesh FDM in theory. To answer the question if the better performance of the coarse-mesh FDM for CANDU-type reactors was just a coincidence (cancelation of error) or caused by the use of heavy water or the use of lattice-homogenized cross sections for the cluster fuel geometry in the diffusion calculation, three benchmark problems with three different fuel lattices (CANDU, HWR and PWR) were designed with the reference solution provided by the Monte-Carlo code SERPENT in this paper. The analysis of these benchmark problems confirm that the better performance of the coarse-mesh FDM for CANDU-type reactors is mainly caused by the use of lattice-homogenized cross sections for the sub-meshes of the cluster fuel geometry in the core-diffusion calculation. When lattice-homogenized cross sections are used in the core-diffusion calculation, it is appropriate to use the fine-mesh FDM for reactors (such as PWR) with uniformly-distributed fuel pins; however, it is inappropriate to use the fine-mesh FDM to analyze CANDU-type reactors with the cluster fuel geometry because the lattice-homogenized cross sections assigned to each sub-mesh are not physically meaningful. It is recommended to use the coarse-mesh (2 × 2 meshes per lattice) to analyze CANDU-type reactors when lattice-homogenized cross sections are used in the core-diffusion calculation.

W. Shen

2012-01-01T23:59:59.000Z

345

Separation of transplutonium elements by the method of emulsion membrane extraction  

SciTech Connect (OSTI)

A study is made of the kinetics of extraction of transplutonium elements by liquid emulsions of the type water and oil, containing di-2-ethylhexylphosphoric acid as the carrier and span-80 as the emulsifier. Conditions of efficient extraction and separation of three-valence americium, curium, and californium from solutions of diethylenetriaminepentaacetic acid are identified.

Novikov, A.P.; Myasoedov, B.F.

1988-05-01T23:59:59.000Z

346

Monolithic amplifier with stable, high resistance feedback element and method for fabricating the same  

DOE Patents [OSTI]

A monolithic amplifier includes a stable, high resistance feedback circuit and a dynamic bias circuit. The dynamic bias circuit is formed with active elements matched to those in the amplifier and feedback circuit to compensate for variations in the operating and threshold voltages thereby maintaining a stable resistance in the feedback circuit. 11 figs.

O`Connor, P.

1998-08-11T23:59:59.000Z

347

Spectral element formulation for dynamic analysis of a coupled piezoelectric wafer and beam system  

Science Journals Connector (OSTI)

A spectral element model is developed to represent the dynamic response of a coupled piezoelectric wafer and beam system (CPBS) in which either a single or collocated piezoelectric wafers are bonded to a base beam. The Mindlin-Herrmann rod theory and ... Keywords: A coupled piezoelectric wafer and beam system (CPBS), Collocated piezoelectric wafers, Electro-mechanical interaction, Finite element method, Lamb waves, Spectral element method

Hyun Woo Park; Eun Jin Kim; Ki Lyong Lim; Hoon Sohn

2010-05-01T23:59:59.000Z

348

Method of manufacturing iron aluminide by thermomechanical processing of elemental powders  

DOE Patents [OSTI]

A powder metallurgical process of preparing iron aluminide useful as electrical resistance heating elements having improved room temperature ductility, electrical resistivity, cyclic fatigue resistance, high temperature oxidation resistance, low and high temperature strength, and/or resistance to high temperature sagging. The iron aluminide has an entirely ferritic microstructure which is free of austenite and can include, in weight %, 20 to 32% Al, and optional additions such as .ltoreq.1% Cr, .gtoreq.05% Zr or ZrO.sub.2 stringers extending perpendicular to an exposed surface of the heating element, .ltoreq.2% Ti, .ltoreq.2% Mo, .ltoreq.1% Zr, .ltoreq.1% C, .ltoreq.0.1% B, .ltoreq.30% oxide dispersoid and/or electrically insulating or electrically conductive covalent ceramic particles, .ltoreq.1 % rare earth metal, .ltoreq.1% oxygen, and/or .ltoreq.3% Cu. The process includes forming a mixture of aluminum powder and iron powder, shaping the mixture into an article such as by cold rolling the mixture into a sheet, and sintering the article at a temperature sufficient to react the iron and aluminum powders and form iron aluminide. The sintering can be followed by hot or cold rolling to reduce porosity created during the sintering step and optional annealing steps in a vacuum or inert atmosphere.

Deevi, Seetharama C. (Midlothian, VA); Lilly, Jr., A. Clifton (Chesterfield, VA); Sikka, Vinod K. (Oak Ridge, TN); Hajaligol, Mohammed R. (Richmond, VA)

2000-01-01T23:59:59.000Z

349

FCMLab: A finite cell research toolbox for MATLAB  

Science Journals Connector (OSTI)

Abstract The recently introduced Finite Cell Method combines the fictitious domain idea with the benefits of high-order finite elements. Although previous publications demonstrated the method’s excellent applicability in various contexts, the implementation of a three-dimensional Finite Cell code is challenging. To lower the entry barrier, this work introduces the object-oriented MATLAB toolbox \\{FCMLab\\} allowing for an easy start into this research field and for rapid prototyping of new algorithmic ideas. The paper reviews the essentials of the methods applied and explains in detail the class structure of the framework. Furthermore, the usage of the toolbox is discussed by means of different two- and three-dimensional examples demonstrating all important features of \\{FCMLab\\} (http://fcmlab.cie.bgu.tum.de/).

N. Zander; T. Bog; M. Elhaddad; R. Espinoza; H. Hu; A. Joly; C. Wu; P. Zerbe; A. Düster; S. Kollmannsberger; J. Parvizian; M. Ruess; D. Schillinger; E. Rank

2014-01-01T23:59:59.000Z

350

A Moving Mesh Numerical Method for Hyperbolic Conservation Laws  

E-Print Network [OSTI]

Aug 3, 2005 ... 173 (Jan., 1986), 59-69. ... PAGES 59-69 ..... S. F. DAVIS & J. E. FLAHERTY, “An adaptive finite element method for initial-value problems for.

351

SH wave scattering from 2-D fractures using boundary element method with linear slip boundary condition  

Science Journals Connector (OSTI)

......guiding the development of geothermal energy reservoirs. This is because...complexity and computational cost of this method could be...there is no additional cost to calculate multiple...Project within the Eni-MIT Energy Initiative Founding Member......

Tianrun Chen; Michael Fehler; Xinding Fang; Xuefeng Shang; Daniel Burns

2012-01-01T23:59:59.000Z

352

A measurement of the top quark mass with a matrix element method  

SciTech Connect (OSTI)

The authors present a measurement of the mass of the top quark. The event sample is selected from proton-antiproton collisions, at 1.96 TeV center-of-mass energy, observed with the CDF detector at Fermilab's Tevatron. They consider a 318 pb{sup -1} dataset collected between March 2002 and August 2004. They select events that contain one energetic lepton, large missing transverse energy, exactly four energetic jets, and at least one displaced vertex b tag. The analysis uses leading-order t{bar t} and background matrix elements along with parameterized parton showering to construct event-by-event likelihoods as a function of top quark mass. From the 63 events observed with the 318 pb{sup -1} dataset they extract a top quark mass of 172.0 {+-} 2.6(stat) {+-} 3.3(syst) GeV/c{sup 2} from the joint likelihood. The mean expected statistical uncertainty is 3.2 GeV/c{sup 2} for m{sub t} = 178 GTeV/c{sup 2} and 3.1 GeV/c{sup 2} for m{sub t} = 172.5 GeV/c{sup 2}. The systematic error is dominated by the uncertainty of the jet energy scale.

Gibson, Adam Paul; /UC, Berkeley

2006-12-01T23:59:59.000Z

353

It's Elemental - The Element Phosphorus  

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

Silicon Silicon Previous Element (Silicon) The Periodic Table of Elements Next Element (Sulfur) Sulfur The Element Phosphorus [Click for Isotope Data] 15 P Phosphorus 30.973762 Atomic Number: 15 Atomic Weight: 30.973762 Melting Point: 317.30 K (44.15°C or 111.47°F) Boiling Point: 553.65 K (280.5°C or 536.9°F) Density: 1.82 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Non-metal Period Number: 3 Group Number: 15 Group Name: Pnictogen What's in a name? From the Greek word for light bearing, phosphoros. Say what? Phosphorus is pronounced as FOS-fer-es. History and Uses: In what is perhaps the most disgusting method of discovering an element, phosphorus was first isolated in 1669 by Hennig Brand, a German physician and alchemist, by boiling, filtering and otherwise processing as many as 60

354

Passive electrically switchable circuit element having improved tunability and method for its manufacture  

DOE Patents [OSTI]

A resistive switching device and methods for making the same are disclosed. In the above said device, a resistive switching layer is interposed between opposing electrodes. The resistive switching layer comprises at least two sub-layers of switchable insulative material characterized by different ionic mobilities.

Mickel, Patrick R; James, Conrad D

2014-09-16T23:59:59.000Z

355

Three-dimensional coupled ground water flow, thermal transport and/or migration of nuclides analysis by boundary element method  

SciTech Connect (OSTI)

In the safety analyses of radioactive waste disposal, it is important and indispensable to analyze coupled problems of ground water flow, thermal transport and/or migration of nuclides. The three-dimensional coupled problems is solved by boundary element method in this paper. The results of this method are compared with those experiments of JAERI and STRIPA SWEDEN on the thermal problem, and with those analyses of analytical and FEM results on the migration problem. In this formulation, natural convection is considered by Boussinesq approximation. An example of coupled ground water flow and migration of nuclides with decay chain U{sup 234} {yields} Th{sup 230} {yields} Ra{sup 226} is also tried.

Kawamura, Ryuji [Information and Mathematical Science Lab., Inc., Kanagawa (Japan)

1994-12-31T23:59:59.000Z

356

Method for quantitative determination and separation of trace amounts of chemical elements in the presence of large quantities of other elements having the same atomic mass  

DOE Patents [OSTI]

Photoionization via autoionizing atomic levels combined with conventional mass spectroscopy provides a technique for quantitative analysis of trace quantities of chemical elements in the presence of much larger amounts of other elements with substantially the same atomic mass. Ytterbium samples smaller than 10 ng have been detected using an ArF* excimer laser which provides the atomic ions for a time-of-flight mass spectrometer. Elemental selectivity of greater than 5:1 with respect to lutetium impurity has been obtained. Autoionization via a single photon process permits greater photon utilization efficiency because of its greater absorption cross section than bound-free transitions, while maintaining sufficient spectroscopic structure to allow significant photoionization selectivity between different atomic species. Separation of atomic species from others of substantially the same atomic mass is also described.

Miller, C.M.; Nogar, N.S.

1982-09-02T23:59:59.000Z

357

Massively Parallel Spectral Element Large Eddy Simulation of a Turbulent Channel Using Wall Models  

E-Print Network [OSTI]

the strength and ability to push forward and succeed. I owe you guys everything and nobody could ask for a better family. I love you all. iv NOMENCLATURE CFD Computational Fluid Dynamics DNS Direct Numerical Simulation RANS Reynolds Averaged Navier...-Stokes LES Large Eddy Simulation FEM Finite Element Method SEM Spectral Element Method SGS Sub-Grid Scale TLM Two Layer Method Re Reynolds Number Re Friction Reynolds Number U1 Characteristic Velocity GLL Gauss-Lobatto-Legendre Cs Smagorinski Coe...

Rabau, Joshua I

2013-05-01T23:59:59.000Z

358

It's Elemental - The Element Copper  

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

Nickel Nickel Previous Element (Nickel) The Periodic Table of Elements Next Element (Zinc) Zinc The Element Copper [Click for Isotope Data] 29 Cu Copper 63.546 Atomic Number: 29 Atomic Weight: 63.546 Melting Point: 1357.77 K (1084.62°C or 1984.32°F) Boiling Point: 2835 K (2562°C or 4644°F) Density: 8.933 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 4 Group Number: 11 Group Name: none What's in a name? From the Latin word cuprum, which means "from the island of Cyprus." Say what? Copper is pronounced as KOP-er. History and Uses: Archaeological evidence suggests that people have been using copper for at least 11,000 years. Relatively easy to mine and refine, people discovered methods for extracting copper from its ores at least 7,000 years ago. The

359

It's Elemental - The Element Hafnium  

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

Lutetium Lutetium Previous Element (Lutetium) The Periodic Table of Elements Next Element (Tantalum) Tantalum The Element Hafnium [Click for Isotope Data] 72 Hf Hafnium 178.49 Atomic Number: 72 Atomic Weight: 178.49 Melting Point: 2506 K (2233°C or 4051°F) Boiling Point: 4876 K (4603°C or 8317°F) Density: 13.3 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 6 Group Number: 4 Group Name: none What's in a name? From the Latin word for the city of Copenhagen, Hafnia. Say what? Hafnium is pronounced as HAF-neeem. History and Uses: Hafnium was discovered by Dirk Coster, a Danish chemist, and Charles de Hevesy, a Hungarian chemist, in 1923. They used a method known as X-ray spectroscopy to study the arrangement of the outer electrons of atoms in

360

Development of a failure prediction method for grout filled damaged tubular members  

E-Print Network [OSTI]

B ? METHOD FOR DETERMINING THE BUCKLING CAPACITY OF AN UNDENTED/UNGROUTED STEEL TUBULAR 86 APPENDIX C ? METHOD FOR DETERMINING THE BUCKLING CAPACITY OF AN UNDENTED/GROUTED STEEL TUBULAR 99 APPENDIX D ? ABAQUS INPUT FILE FOR FINITE ELEMENT... MODEL ?I 114 APPENDIX E ? ABAQUS INPUT FILE FOR FINITE ELEMENT MODEL //2 APPENDIX F - LISTING OF BUCKLE FORTRAN PROGRAM 122 130 APPENDIX G ? METHOD FOR DETERMINING THE BUCKLING CAPACITY OF A DENTED/GROUTED STEEL TUBULAR 135 VITA . . 157 Table...

Schank, Paul Edward

1993-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Modeling of underwater noise from pile driving using coupled finite element and parabolic equation model with improved parabolic equation starting field  

Science Journals Connector (OSTI)

An offshore wind farm will be constructed in the Yellow Sea west of Korean Peninsula where there are extensive fishing activity and numerous fishery farms. To study the effect of underwater piling noise on fishing and marine lives we model the pile driving noise propagation using coupled FE and PE model. The near-field noise is computed by FE model considering detailed specifications of the pile driving system. We apply 2D axis-symmetric geometry and utilize acoustic structure interaction analysis in the frequency domain. The FE results are used to compose the starting field for PE model where appropriate range selection is an important factor to cover most of the contributing ray paths. Extrapolation technique to compensate the lack of FE data and the numerical filtering method to smooth the FE result are discussed. In the far-field the noise propagation is modeled by the split step Pade PE algorithm. The improved PE starting field seems to give refined result than previous coupled model.

Jungyong Park

2013-01-01T23:59:59.000Z

362

Elements & Compounds Atoms (Elements)  

E-Print Network [OSTI]

#12;Elements & Compounds #12;Atoms (Elements) Molecules (Compounds) Cells Elements & Compounds #12;Nucleus Electrons Cloud of negative charge (2 electrons) Fig. 2.5: Simplified model of a Helium (He) Atom He 4.002602 2 Helium Mass Number (~atomic mass) = number of Neutrons + Protons = 4 for Helium Atomic

Frey, Terry

363

Finite Element Approximation of Coupled Seismic and ...  

E-Print Network [OSTI]

negative sign) is balanced by adsorbed positive ions of the surrounding fluid, setting ... Further from the surface there exists a distribution of mobile counter ions, ...

2009-02-15T23:59:59.000Z

364

Finite element decomposition of the human neocortex  

E-Print Network [OSTI]

. . . . . . . . . . . . . . . . . . . . . ?. .. . , . . . . . C. Application of Software Tools to the Human Neocortex. . . . . . . . 72 . . . . 72 . . . . 74 VIII RESULTS. . . . . 77 A. B. C. D. E. F. Contour Extraction . , Solid Model Reconstruction of the Right Hemisphere. . . . Extraction.... Summary. B. Future Work. . . . . . 101 . . . . . 101 REFERENCES. , . . . . . 105 . . . . . 110 LIST OF FIGURES FIGURE Page 1 Reconstruction stages. . . . . . 2 Voronoi diagram and Delaunay triangulation . . . . . 13 3 IVS and EVS of two contours...

Chow, Seeling

2012-06-07T23:59:59.000Z

365

Finite element analysis of shells with layers  

E-Print Network [OSTI]

It is well established that thin shell structures frequently feature narrow bands of strain concentration and localized displacement irregularities referred to as boundary and internal layers. It is crucial to capture these ...

Hiller, Jean-François, 1974-

2002-01-01T23:59:59.000Z

366

Finite element simulation of electrorheological fluids  

E-Print Network [OSTI]

Electrorheological (ER) fluids change their flow properties dramatically when an electric field is applied. These fluids are usually composed of dispersions of polarizable particles in an insulating base fluid or composed ...

Rhyou, Chanryeol, 1973-

2005-01-01T23:59:59.000Z

367

Finite element approximation of coupled seismic and ...  

E-Print Network [OSTI]

Facultad de Ciencias Astronómicas y Geof? sicas, Universidad Nacional de La Plata and Department of Mathematics, Purdue University. Joint work with Fabio I.

368

An AMR Capable Finite Element Diffusion Solver  

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

hydrocodes have been used extensively at the National Ignition Facility (NIF) to model ignition target behavior during 1 and after the delivery of laser power 23. Over the...

369

Construction of Higher Order Finite Element with  

E-Print Network [OSTI]

accuracy, stability Previous work: ffl Cohen, Joly, Tordjman (2D, construction, analysis, performance) ffl \\Gamma4 [b] with b = â?? 1 â?? 2 â?? 3 â?? 4 (bubble function), and b f a iface bubblej function. Accuracy

Kern, Michel

370

Hierarchical strategy for rapid finite element analysis  

E-Print Network [OSTI]

that is being researched quite extensively due to its high strength and stiffness. But it is hard to model because other phenomena like quantum mechanics come into play in the nano-scale and conventional continuum mechanics is not valid at such scales. So... that is being researched quite extensively due to its high strength and stiffness. But it is hard to model because other phenomena like quantum mechanics come into play in the nano-scale and conventional continuum mechanics is not valid at such scales. So...

Varghese, Julian

2004-09-30T23:59:59.000Z

371

linear-elements-code.scm  

E-Print Network [OSTI]

(o Linear-finite-element-operator)) ;; initialize various fields that depend on the space ;; if coefficients is not defined, we set it to arrays of floating-point ;; zeros ...

372

BLT-EC (Breach, Leach Transport, and Equilibrium Chemistry), a finite-element model for assessing the release of radionuclides from low-level waste disposal units: Background, theory, and model description  

SciTech Connect (OSTI)

Performance assessment models typically account for the processes of sorption and dissolution-precipitation by using an empirical distribution coefficient, commonly referred to as K{sub d} that combines the effects of all chemical reactions between solid and aqueous phases. In recent years, however, there has been an increasing awareness that performance assessments based solely on empirically based K{sub d} models may be incomplete, particularly for applications involving radionuclides having sorption and solubility properties that are sensitive to variations in the in-situ chemical environment. To accommodate variations in the in-situ chemical environment, and to assess its impact on radionuclide mobility, it is necessary to model radionuclide release, transport, and chemical processes in a coupled fashion. This modeling has been done and incorporated into the two-dimensional, finite-element, computer code BLT-EC (Breach, Leach, Transport, Equilibrium Chemistry). BLT-EC is capable of predicting container degradation, waste-form leaching, and advective-dispersive, multispecies, solute transport. BLT-EC accounts for retardation directly by modeling the chemical processes of complexation, sorption, dissolution-precipitation, ion-exchange, and oxidation-reduction reactions. In this report we: (1) present a detailed description of the various physical and chemical processes that control the release and migration of radionuclides from shallow land LLW disposal facilities; (2) formulate the mathematical models that represent these processes; (3) outline how these models are incorporated and implemented in BLT-EC; and (4) demonstrate the application of BLT-EC on a set of example problems.

MacKinnon, R.J.; Sullivan, T.M. [Brookhaven National Lab., Upton, NY (United States); Simonson, S.A. [Massachusetts Inst. of Technology, Cambridge, MA (United States); Suen, C.J. [California State Univ., Fresno, CA (United States)

1995-08-01T23:59:59.000Z

373

Methods and computer executable instructions for rapidly calculating simulated particle transport through geometrically modeled treatment volumes having uniform volume elements for use in radiotherapy  

DOE Patents [OSTI]

Methods and computer executable instructions are disclosed for ultimately developing a dosimetry plan for a treatment volume targeted for irradiation during cancer therapy. The dosimetry plan is available in "real-time" which especially enhances clinical use for in vivo applications. The real-time is achieved because of the novel geometric model constructed for the planned treatment volume which, in turn, allows for rapid calculations to be performed for simulated movements of particles along particle tracks there through. The particles are exemplary representations of neutrons emanating from a neutron source during BNCT. In a preferred embodiment, a medical image having a plurality of pixels of information representative of a treatment volume is obtained. The pixels are: (i) converted into a plurality of substantially uniform volume elements having substantially the same shape and volume of the pixels; and (ii) arranged into a geometric model of the treatment volume. An anatomical material associated with each uniform volume element is defined and stored. Thereafter, a movement of a particle along a particle track is defined through the geometric model along a primary direction of movement that begins in a starting element of the uniform volume elements and traverses to a next element of the uniform volume elements. The particle movement along the particle track is effectuated in integer based increments along the primary direction of movement until a position of intersection occurs that represents a condition where the anatomical material of the next element is substantially different from the anatomical material of the starting element. This position of intersection is then useful for indicating whether a neutron has been captured, scattered or exited from the geometric model. From this intersection, a distribution of radiation doses can be computed for use in the cancer therapy. The foregoing represents an advance in computational times by multiple factors of time magnitudes.

Frandsen, Michael W. (Helena, MT); Wessol, Daniel E. (Bozeman, MT); Wheeler, Floyd J. (Idaho Falls, ID)

2001-01-16T23:59:59.000Z

374

Introduction Positive finite rank . . .  

E-Print Network [OSTI]

Introduction Positive finite rank . . . Positive finite rank . . . Positive finite rank . . . ¯� I qixf1981@sxu.edu.cn #12;Introduction Positive finite rank . . . Positive finite rank . . . Positive finite rank . . . ¯� I K 12 19 £ ¶w« ' 4 ò � 1 Introduction · In quantum mechanics, a quantum system

Li, Chi-Kwong

375

Assessment of Delaware and Groningen effects on dual-laterolog measurements with a self-adaptive hp finite-element method  

E-Print Network [OSTI]

Assessment of Delaware and Groningen effects on dual-laterolog measurements with a self-adaptive hp and Groningen effects. Both effects give rise to abnormally high readings of DLL measurements under extreme laterolog mea- surements, generating the so-called Groningen effect. INTRODUCTION The electrical resistivity

Torres-Verdín, Carlos

376

An analysis of the effect of coupling between temperature rise and light distribution in laser irradiated tissue using finite element and Monte-Carlo methods  

E-Print Network [OSTI]

, there are not many changes in Q with time because, as Figure 7 shows, it takes too long to reach the desired damage index 23 Axial (r, z'+I) r rO O~ Ti+l, i+I ri+I, Zi+I ) r, z) +1, 1 f4 (ri, z) (ri+I, zi) Radial Pig. 9. Diagram for interpolation between..., there are not many changes in Q with time because, as Figure 7 shows, it takes too long to reach the desired damage index 23 Axial (r, z'+I) r rO O~ Ti+l, i+I ri+I, Zi+I ) r, z) +1, 1 f4 (ri, z) (ri+I, zi) Radial Pig. 9. Diagram for interpolation between...

Kim, Beop-Min

2012-06-07T23:59:59.000Z

377

Simulation of millisecond catalytic partial oxidation of methane in a monolithic reactor for the production of hydrogen using finite element methods.  

E-Print Network [OSTI]

??Hydrogen can be the key solution of all our energy needs in the future and to face climate change while reducing greenhouse gases. Syngas, H… (more)

Flynn, Julie.

2006-01-01T23:59:59.000Z

379

Dynamics of multiphase flows via spectral boundary elements and parallel computations  

E-Print Network [OSTI]

acceleration is g, while the surface tension is assumed constant. Far from the droplet, the flow approaches. 1. INTRODUCTION The dynamics of droplets and bubbles in infinite media or in restricted geometries convergence and numerical stability) and the versatility of the finite element method (i.e. the ability

Dimitrakopoulos, Panagiotis

380

Partitioning of radionuclides and trace elements in phosphogypsum and its source materials based on sequential extraction methods  

Science Journals Connector (OSTI)

Phosphogypsum is a waste produced by the phosphate fertilizer industry. Although phosphogypsum is mainly calcium sulphate dihydrate, it contains elevated levels of impurities, which originate from the source phosphate rock used in the phosphoric acid production. Among these impurities, radionuclides from 238U and 232Th decay series are of most concern due to their radiotoxicity. Other elements, such as rare earth elements (REE) and Ba are also enriched in the phosphogypsum. The bioavailability of radionuclides (226Ra, 210Pb and 232Th), rare earth elements and Ba to the surrounding aquatic system was evaluated by the application of sequential leaching of the phosphogypsum samples from the Brazilian phosphoric acid producers. The sequential extraction results show that most of the radium and lead are located in the “iron oxide” (non-CaSO4) fraction, and that only 13–18% of these radionuclides are distributed in the most labile fraction. Th, REE and Ba were found predominantly in the residual phase, which corresponds to a small fraction of the phosphate rock or monazite that did not react and to insoluble compounds such as sulphates, phosphates and silicates. It can be concluded that although all these elements are enriched in the phosphogypsum samples they are not associated with CaSO4 itself and therefore do not represent a threat to the surrounding aquatic environment.

A.J.G. Santos; B.P. Mazzilli; D.I.T. Fávaro; P.S.C. Silva

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Peculiarities of a method for ex-reactor heating of electrodes and obtaining voltage-current characteristics of multi-cell thermionic fuel elements  

SciTech Connect (OSTI)

The paper discusses principle of operation and applications of a pulse method of heating multi-cell thermionic fuel elements. Some experimental results are given for a cylindrical single-cell thermionic energy converter that simulates conditions close to that of multi-cell TFE operation. Basic requirements for technical parameters are stated that should be observed when testing TFE on thermal facilities. The means to improve the method are described, including both a computer-aided experiment and modifications in individual components of the test facility. {copyright} {ital 1996 American Institute of Physics.}

Kalandarishvili, A.G. [Sukhumi Institute of Physics and Engineering, Tbilisi 380008 Republic of (Georgia); Drozdov, A.A. [RRC ``Kurchatov Institute``, Moscow 123182 (Russia); Stepennov, B.S. [INERTEK, Moscow 123182 (Russia)

1996-03-01T23:59:59.000Z

382

Programmatic Elements  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

The Guide provides acceptable methods of meeting the requirements of DOE O 151.1C for programmatic elements that sustain the emergency management program and maintain the readiness of the program to respond to an emergency. Cancels DOE G 151.1-1, Volume 5-1, DOE G 151.1-1, Volume 5-2, DOE G 151.1-1, Volume 5-3, DOE G 151.1-1, Volume 5-4, DOE G 151.1-1, Volume 7-1, and DOE G 151.1-1, Volume 7-3.

2007-07-11T23:59:59.000Z

383

The interior penalty discontinuous Galerkin method for elastic wave ...  

E-Print Network [OSTI]

SUMMARY. Recently, there has been an increased interest in applying the discontinuous Galerkin method ... methods to approximate the propagation of acoustic and elastic waves in the ...... the SEM that it can handle non-conforming finite-element meshes ... and Technology (CONACYT) and a PhD summer support by the.

Ambika p PrasadTECHBOOKS

2008-09-16T23:59:59.000Z

384

Method and system for laser-based formation of micro-shapes in surfaces of optical elements  

DOE Patents [OSTI]

A method of forming a surface feature extending into a sample includes providing a laser operable to emit an output beam and modulating the output beam to form a pulse train having a plurality of pulses. The method also includes a) directing the pulse train along an optical path intersecting an exposed portion of the sample at a position i and b) focusing a first portion of the plurality of pulses to impinge on the sample at the position i. Each of the plurality of pulses is characterized by a spot size at the sample. The method further includes c) ablating at least a portion of the sample at the position i to form a portion of the surface feature and d) incrementing counter i. The method includes e) repeating steps a) through d) to form the surface feature. The sample is free of a rim surrounding the surface feature.

Bass, Isaac Louis; Guss, Gabriel Mark

2013-03-05T23:59:59.000Z

385

Evaluation of Wet Chemical ICP-AES Elemental Analysis Methods usingSimulated Hanford Waste Samples-Phase I Interim Report  

SciTech Connect (OSTI)

The wet chemistry digestion method development for providing process control elemental analyses of the Hanford Tank Waste Treatment and Immobilization Plant (WTP) Melter Feed Preparation Vessel (MFPV) samples is divided into two phases: Phase I consists of: (1) optimizing digestion methods as a precursor to elemental analyses by ICP-AES techniques; (2) selecting methods with the desired analytical reliability and speed to support the nine-hour or less turnaround time requirement of the WTP; and (3) providing baseline comparison to the laser ablation (LA) sample introduction technique for ICP-AES elemental analyses that is being developed at the Savannah River National Laboratory (SRNL). Phase II consists of: (1) Time-and-Motion study of the selected methods from Phase I with actual Hanford waste or waste simulants in shielded cell facilities to ensure that the methods can be performed remotely and maintain the desired characteristics; and (2) digestion of glass samples prepared from actual Hanford Waste tank sludge for providing comparative results to the LA Phase II study. Based on the Phase I testing discussed in this report, a tandem digestion approach consisting of sodium peroxide fusion digestions carried out in nickel crucibles and warm mixed-acid digestions carried out in plastic bottles has been selected for Time-and-Motion study in Phase II. SRNL experience with performing this analytical approach in laboratory hoods indicates that well-trained cell operator teams will be able to perform the tandem digestions in five hours or less. The selected approach will produce two sets of solutions for analysis by ICP-AES techniques. Four hours would then be allocated for performing the ICP-AES analyses and reporting results to meet the nine-hour or less turnaround time requirement. The tandem digestion approach will need to be performed in two separate shielded analytical cells by two separate cell operator teams in order to achieve the nine-hour or less turnaround time. Because of the simplicity of the warm mixed-acid method, a well-trained cell operator team may in time be able to perform both sets of digestions. However, having separate shielded cells for each of the methods is prudent to avoid overcrowding problems that would impede a minimal turnaround time.

Coleman, Charles J.; Edwards, Thomas B.

2005-04-30T23:59:59.000Z

386

Summary compilation of shell element performance versus formulation.  

SciTech Connect (OSTI)

This document compares the finite element shell formulations in the Sierra Solid Mechanics code. These are finite elements either currently in the Sierra simulation codes Presto and Adagio, or expected to be added to them in time. The list of elements are divided into traditional two-dimensional, plane stress shell finite elements, and three-dimensional solid finite elements that contain either modifications or additional terms designed to represent the bending stiffness expected to be found in shell formulations. These particular finite elements are formulated for finite deformation and inelastic material response, and, as such, are not based on some of the elegant formulations that can be found in an elastic, infinitesimal finite element setting. Each shell element is subjected to a series of 12 verification and validation test problems. The underlying purpose of the tests here is to identify the quality of both the spatially discrete finite element gradient operator and the spatially discrete finite element divergence operator. If the derivation of the finite element is proper, the discrete divergence operator is the transpose of the discrete gradient operator. An overall summary is provided from which one can rank, at least in an average sense, how well the individual formulations can be expected to perform in applications encountered year in and year out. A letter grade has been assigned albeit sometimes subjectively for each shell element and each test problem result. The number of A's, B's, C's, et cetera assigned have been totaled, and a grade point average (GPA) has been computed, based on a 4.0-system. These grades, combined with a comparison between the test problems and the application problem, can be used to guide an analyst to select the element with the best shell formulation.

Heinstein, Martin Wilhelm; Hales, Jason Dean (Idaho National Laboratory, Idaho Falls, ID); Breivik, Nicole L.; Key, Samuel W. (FMA Development, LLC, Great Falls, MT)

2011-07-01T23:59:59.000Z

387

Cohesive-zone-model formulation and implementation using the symmetric Galerkin boundary element method for homogeneous solids  

Science Journals Connector (OSTI)

A new symmetric boundary integral formulation for cohesive cracks growing in the interior of homogeneous linear elastic isotropic media with a known crack path is developed and implemented in a numerical code. A crack path can be known due to some symmetry ... Keywords: Arc-length method, Cohesive zone model, Crack growth, Fracture mechanics, Symmetric boundary integral equation

Luis Távara; Vladislav Manti?; Alberto Salvadori; Leonard J. Gray; Federico París

2013-04-01T23:59:59.000Z

388

Response Elements  

Broader source: Directives, Delegations, and Requirements [Office of Management (MA)]

The Guide provides acceptable methods for meeting the requirement of DOE O 151.1C for response elements that respond or contribute to response as needed in an emergency. Cancels DOE G 151.1-1, Volume 3-1, DOE G 151.1-1, Volume 3-2, DOE G 151.1-1, Volume 3-3, DOE G 151.1-1, Volume 3-4, DOE G 151.1-1, Volume 4-1, DOE G 151.1-1, Volume 4-2, DOE G 151.1-1, Volume 4-3, DOE G 151.1-1, Volume 4-4, DOE G 151.1-1, Volume 4-5, and DOE G 151.1-1, Volume 4-6.

2007-07-11T23:59:59.000Z

389

E-Print Network 3.0 - anisotropic hexahedra finite Sample Search...  

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

especially with respect to finite element... analyses within highly elastic, and plas- tic, structural domains. However, because hexahedral ... Source: Utah, University of -...

390

A Generalized Finite Source Calibration Factor: A Natural Improvement to the Finite Source Correction Factor for Uranium Holdup Measurements  

SciTech Connect (OSTI)

This paper proposes refinements to the finite source correction factor used in holdup measurements. Specifically it focuses on a more general method to estimate the average detector response for a finite source. This proposed method for the average detector response is based directly on the Generalized Geometry Holdup (GGH) assay method. First, the finite source correction factor as originally proposed is reviewed in this paper. Following this review the GGH assay method is described. Lastly, a new finite area calibration factor based on GGH is then proposed for finite point and line sources. As an alternative to the direct use of the finite arca calibration factor, finite source correction factors are also derived from this calibration factor. This new correction factor can be used in a manner similar to the finite source correction factor as currently implemented.

Gunn, C.A.; Oberer, R.B.; chiang, L.G.; Ceo, R.N.

2003-01-28T23:59:59.000Z

391

A Finite Landscape?  

E-Print Network [OSTI]

We present evidence that the number of string/$M$ theory vacua consistent with experiments is a finite number. We do this both by explicit analysis of infinite sequences of vacua and by applying various mathematical finiteness theorems.

Bobby S Acharya; Michael R Douglas

2006-06-21T23:59:59.000Z

392

It's Elemental - The Element Europium  

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

Samarium Samarium Previous Element (Samarium) The Periodic Table of Elements Next Element (Gadolinium) Gadolinium The Element Europium [Click for Isotope Data] 63 Eu Europium 151.964 Atomic Number: 63 Atomic Weight: 151.964 Melting Point: 1095 K (822°C or 1512°F) Boiling Point: 1802 K (1529°C or 2784°F) Density: 5.24 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 6 Group Number: none Group Name: Lanthanide What's in a name? Named after the continent of Europe. Say what? Europium is pronounced as yoo-RO-pee-em. History and Uses: Europium was discovered by Eugène-Antole Demarçay, a French chemist, in 1896. Demarçay suspected that samples of a recently discovered element, samarium, were contaminated with an unknown element. He was able to produce

393

It's Elemental - The Element Potassium  

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

Argon Argon Previous Element (Argon) The Periodic Table of Elements Next Element (Calcium) Calcium The Element Potassium [Click for Isotope Data] 19 K Potassium 39.0983 Atomic Number: 19 Atomic Weight: 39.0983 Melting Point: 336.53 K (63.38°C or 146.08°F) Boiling Point: 1032 K (759°C or 1398°F) Density: 0.89 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 4 Group Number: 1 Group Name: Alkali Metal What's in a name? From the English word potash. Potassium's chemical symbol comes from the Latin word for alkali, kalium. Say what? Potassium is pronounced as poh-TASS-ee-em. History and Uses: Although potassium is the eighth most abundant element on earth and comprises about 2.1% of the earth's crust, it is a very reactive element

394

It's Elemental - The Element Sulfur  

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

Phosphorus Phosphorus Previous Element (Phosphorus) The Periodic Table of Elements Next Element (Chlorine) Chlorine The Element Sulfur [Click for Isotope Data] 16 S Sulfur 32.065 Atomic Number: 16 Atomic Weight: 32.065 Melting Point: 388.36 K (115.21°C or 239.38°F) Boiling Point: 717.75 K (444.60°C or 832.28°F) Density: 2.067 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Non-metal Period Number: 3 Group Number: 16 Group Name: Chalcogen What's in a name? From the Sanskrit word sulvere and the Latin word sulphurium. Say what? Sulfur is pronounced as SUL-fer. History and Uses: Sulfur, the tenth most abundant element in the universe, has been known since ancient times. Sometime around 1777, Antoine Lavoisier convinced the rest of the scientific community that sulfur was an element. Sulfur is a

395

It's Elemental - The Element Magnesium  

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Sodium Sodium Previous Element (Sodium) The Periodic Table of Elements Next Element (Aluminum) Aluminum The Element Magnesium [Click for Isotope Data] 12 Mg Magnesium 24.3050 Atomic Number: 12 Atomic Weight: 24.3050 Melting Point: 923 K (650°C or 1202°F) Boiling Point: 1363 K (1090°C or 1994°F) Density: 1.74 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 3 Group Number: 2 Group Name: Alkaline Earth Metal What's in a name? For Magnesia, a district in the region of Thessaly, Greece. Say what? Magnesium is pronounced as mag-NEE-zhi-em. History and Uses: Although it is the eighth most abundant element in the universe and the seventh most abundant element in the earth's crust, magnesium is never found free in nature. Magnesium was first isolated by Sir Humphry Davy, an

396

It's Elemental - The Element Nitrogen  

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Carbon Carbon Previous Element (Carbon) The Periodic Table of Elements Next Element (Oxygen) Oxygen The Element Nitrogen [Click for Isotope Data] 7 N Nitrogen 14.0067 Atomic Number: 7 Atomic Weight: 14.0067 Melting Point: 63.15 K (-210.00°C or -346.00°F) Boiling Point: 77.36 K (-195.79°C or -320.44°F) Density: 0.0012506 grams per cubic centimeter Phase at Room Temperature: Gas Element Classification: Non-metal Period Number: 2 Group Number: 15 Group Name: Pnictogen What's in a name? From the Greek words nitron and genes, which together mean "saltpetre forming." Say what? Nitrogen is pronounced as NYE-treh-gen. History and Uses: Nitrogen was discovered by the Scottish physician Daniel Rutherford in 1772. It is the fifth most abundant element in the universe and makes up

397

It's Elemental - The Element Sodium  

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Neon Neon Previous Element (Neon) The Periodic Table of Elements Next Element (Magnesium) Magnesium The Element Sodium [Click for Isotope Data] 11 Na Sodium 22.98976928 Atomic Number: 11 Atomic Weight: 22.98976928 Melting Point: 370.95 K (97.80°C or 208.04°F) Boiling Point: 1156 K (883°C or 1621°F) Density: 0.97 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 3 Group Number: 1 Group Name: Alkali Metal What's in a name? From the English word soda and from the Medieval Latin word sodanum, which means "headache remedy." Sodium's chemical symbol comes from the Latin word for sodium carbonate, natrium. Say what? Sodium is pronounced as SO-dee-em. History and Uses: Although sodium is the sixth most abundant element on earth and comprises

398

It's Elemental - The Element Francium  

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Radon Radon Previous Element (Radon) The Periodic Table of Elements Next Element (Radium) Radium The Element Francium [Click for Isotope Data] 87 Fr Francium 223 Atomic Number: 87 Atomic Weight: 223 Melting Point: 300 K (27°C or 81°F) Boiling Point: Unknown Density: Unknown Phase at Room Temperature: Solid Element Classification: Metal Period Number: 7 Group Number: 1 Group Name: Alkali Metal Radioactive What's in a name? Named for the country of France. Say what? Francium is pronounced as FRAN-see-em. History and Uses: Francium was discovered by Marguerite Catherine Perey, a French chemist, in 1939 while analyzing actinium's decay sequence. Although considered a natural element, scientists estimate that there is no more than one ounce of francium in the earth's crust at one time. Since there is so little

399

It's Elemental - The Element Cerium  

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Lanthanum Lanthanum Previous Element (Lanthanum) The Periodic Table of Elements Next Element (Praseodymium) Praseodymium The Element Cerium [Click for Isotope Data] 58 Ce Cerium 140.116 Atomic Number: 58 Atomic Weight: 140.116 Melting Point: 1071 K (798°C or 1468°F) Boiling Point: 3697 K (3424°C or 6195°F) Density: 6.770 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 6 Group Number: none Group Name: Lanthanide What's in a name? Named for the asteroid Ceres. Say what? Cerium is pronounced as SER-ee-em. History and Uses: Cerium was discovered by Jöns Jacob Berzelius and Wilhelm von Hisinger, Swedish chemists, and independently by Martin Heinrich Klaproth, a German chemist, in 1803. Cerium is the most abundant of the rare earth elements

400

It's Elemental - The Element Indium  

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Cadmium Cadmium Previous Element (Cadmium) The Periodic Table of Elements Next Element (Tin) Tin The Element Indium [Click for Isotope Data] 49 In Indium 114.818 Atomic Number: 49 Atomic Weight: 114.818 Melting Point: 429.75 K (156.60°C or 313.88°F) Boiling Point: 2345 K (2072°C or 3762°F) Density: 7.31 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 5 Group Number: 13 Group Name: none What's in a name? Named after the bright indigo line in its spectrum. Say what? Indium is pronounced as IN-dee-em. History and Uses: Indium was discovered by the German chemists Ferdinand Reich and Hieronymus Theodor Richter in 1863. Reich and Richter had been looking for traces of the element thallium in samples of zinc ores. A brilliant indigo line in

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401

It's Elemental - The Element Neon  

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

Fluorine Fluorine Previous Element (Fluorine) The Periodic Table of Elements Next Element (Sodium) Sodium The Element Neon [Click for Isotope Data] 10 Ne Neon 20.1797 Atomic Number: 10 Atomic Weight: 20.1797 Melting Point: 24.56 K (-248.59°C or -415.46°F) Boiling Point: 27.07 K (-246.08°C or -410.94°F) Density: 0.0008999 grams per cubic centimeter Phase at Room Temperature: Gas Element Classification: Non-metal Period Number: 2 Group Number: 18 Group Name: Noble Gas What's in a name? From the Greek word for new, neos. Say what? Neon is pronounced as NEE-on. History and Uses: Neon was discovered by Sir William Ramsay, a Scottish chemist, and Morris M. Travers, an English chemist, shortly after their discovery of the element krypton in 1898. Like krypton, neon was discovered through the

402

It's Elemental - The Element Technetium  

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Molybdenum Molybdenum Previous Element (Molybdenum) The Periodic Table of Elements Next Element (Ruthenium) Ruthenium The Element Technetium [Click for Isotope Data] 43 Tc Technetium 98 Atomic Number: 43 Atomic Weight: 98 Melting Point: 2430 K (2157°C or 3915°F) Boiling Point: 4538 K (4265°C or 7709°F) Density: 11 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 5 Group Number: 7 Group Name: none Radioactive and Artificially Produced What's in a name? From the Greek word for artificial, technetos. Say what? Technetium is pronounced as tek-NEE-she-em. History and Uses: Technetium was the first artificially produced element. It was isolated by Carlo Perrier and Emilio Segrè in 1937. Technetium was created by bombarding molybdenum atoms with deuterons that had been accelerated by a

403

It's Elemental - The Element Cobalt  

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Iron Iron Previous Element (Iron) The Periodic Table of Elements Next Element (Nickel) Nickel The Element Cobalt [Click for Isotope Data] 27 Co Cobalt 58.933195 Atomic Number: 27 Atomic Weight: 58.933195 Melting Point: 1768 K (1495°C or 2723°F) Boiling Point: 3200 K (2927°C or 5301°F) Density: 8.86 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 4 Group Number: 9 Group Name: none What's in a name? From the German word for goblin or evil spirit, kobald and the Greek word for mine, cobalos. Say what? Cobalt is pronounced as KO-bolt. History and Uses: Cobalt was discovered by Georg Brandt, a Swedish chemist, in 1739. Brandt was attempting to prove that the ability of certain minerals to color glass blue was due to an unknown element and not to bismuth, as was commonly

404

It's Elemental - The Element Bromine  

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Selenium Selenium Previous Element (Selenium) The Periodic Table of Elements Next Element (Krypton) Krypton The Element Bromine [Click for Isotope Data] 35 Br Bromine 79.904 Atomic Number: 35 Atomic Weight: 79.904 Melting Point: 265.95 K (-7.2°C or 19.0°F) Boiling Point: 331.95 K (58.8°C or 137.8°F) Density: 3.11 grams per cubic centimeter Phase at Room Temperature: Liquid Element Classification: Non-metal Period Number: 4 Group Number: 17 Group Name: Halogen What's in a name? From the Greek word for stench, bromos. Say what? Bromine is pronounced as BRO-meen. History and Uses: The only nonmetallic element that is a liquid at normal room temperatures, bromine was produced by Carl Löwig, a young chemistry student, the summer before starting his freshman year at Heidelberg. When he showed his

405

It's Elemental - The Element Oxygen  

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Nitrogen Nitrogen Previous Element (Nitrogen) The Periodic Table of Elements Next Element (Fluorine) Fluorine The Element Oxygen [Click for Isotope Data] 8 O Oxygen 15.9994 Atomic Number: 8 Atomic Weight: 15.9994 Melting Point: 54.36 K (-218.79°C or -361.82°F) Boiling Point: 90.20 K (-182.95°C or -297.31°F) Density: 0.001429 grams per cubic centimeter Phase at Room Temperature: Gas Element Classification: Non-metal Period Number: 2 Group Number: 16 Group Name: Chalcogen What's in a name? From the greek words oxys and genes, which together mean "acid forming." Say what? Oxygen is pronounced as OK-si-jen. History and Uses: Oxygen had been produced by several chemists prior to its discovery in 1774, but they failed to recognize it as a distinct element. Joseph

406

It's Elemental - The Element Manganese  

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Chromium Chromium Previous Element (Chromium) The Periodic Table of Elements Next Element (Iron) Iron The Element Manganese [Click for Isotope Data] 25 Mn Manganese 54.938045 Atomic Number: 25 Atomic Weight: 54.938045 Melting Point: 1519 K (1246°C or 2275°F) Boiling Point: 2334 K (2061°C or 3742°F) Density: 7.3 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 4 Group Number: 7 Group Name: none What's in a name? From the Latin word for magnet, magnes. Say what? Manganese is pronounced as MAN-ge-nees. History and Uses: Proposed to be an element by Carl Wilhelm Scheele in 1774, manganese was discovered by Johan Gottlieb Gahn, a Swedish chemist, by heating the mineral pyrolusite (MnO2) in the presence of charcoal later that year.

407

It's Elemental - The Element Titanium  

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Scandium Scandium Previous Element (Scandium) The Periodic Table of Elements Next Element (Vanadium) Vanadium The Element Titanium [Click for Isotope Data] 22 Ti Titanium 47.867 Atomic Number: 22 Atomic Weight: 47.867 Melting Point: 1941 K (1668°C or 3034°F) Boiling Point: 3560 K (3287°C or 5949°F) Density: 4.5 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 4 Group Number: 4 Group Name: none What's in a name? From the Greek word Titans, the mythological "first sons of the Earth." Say what? Titanium is pronounced as tie-TAY-nee-em. History and Uses: Titanium was discovered in 1791 by the Reverend William Gregor, an English pastor. Pure titanium was first produced by Matthew A. Hunter, an American metallurgist, in 1910. Titanium is the ninth most abundant element in the

408

Finiteness properties and profinite completions  

Science Journals Connector (OSTI)

......finite or of finite index, [14, Chapter...PROPERTIES AND PROFINITE COMPLETIONS 107 Finally, by...every finite index subgroup of a finitely...the profinite completion of a finitely generated...for every finite index subgroup...same pronilpotent completion they also have the......

Alexander Lubotzky

2014-02-01T23:59:59.000Z

409

Measurement of the Top Quark Mass at D0 Run II with the Matrix Element Method in the Lepton+Jets Final State  

SciTech Connect (OSTI)

The mass of the top quark is a fundamental parameter of the Standard Model. Its precise knowledge yields valuable insights into unresolved phenomena in and beyond the Standard Model. A measurement of the top quark mass with the matrix element method in the lepton+jets final state in D0 Run II is presented. Events are selected requiring an isolated energetic charged lepton (electron or muon), significant missing transverse energy, and exactly four calorimeter jets. For each event, the probabilities to originate from the signal and background processes are calculated based on the measured kinematics, the object resolutions and the respective matrix elements. The jet energy scale is known to be the dominant source of systematic uncertainty. The reference scale for the mass measurement is derived from Monte Carlo events. The matrix element likelihood is defined as a function of both, m{sub top} and jet energy scale JES, where the latter represents a scale factor with respect to the reference scale. The top mass is obtained from a two-dimensional correlated fit, and the likelihood yields both the statistical and jet energy scale uncertainty. Using a dataset of 320 pb{sup -1} of D0 Run II data, the mass of the top quark is measured to be: m{sub top}{sup {ell}+jets} = 169.5 {+-} 4.4(stat. + JES){sub -1.6}{sup +1.7}(syst.) GeV; m{sub top}{sup e+jets} = 168.8 {+-} 6.0(stat. + JES){sub -1.9}{sup +1.9}(syst.) GeV; m{sub top}{sup {mu}+jets} = 172.3 {+-} 9.6(stat.+JES){sub -3.3}{sup +3.4}(syst.) GeV. The jet energy scale measurement in the {ell}+jets sample yields JES = 1.034 {+-} 0.034, suggesting good consistency of the data with the simulation. The measurement forecasts significant improvements to the total top mass uncertainty during Run II before the startup of the LHC, as the data sample will grow by a factor of ten and D0's tracking capabilities will be employed in jet energy reconstruction and flavor identification.

Schieferdecker, Philipp; /Munich U.; ,

2005-08-01T23:59:59.000Z

410

It's Elemental - The Element Astatine  

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Polonium Polonium Previous Element (Polonium) The Periodic Table of Elements Next Element (Radon) Radon The Element Astatine [Click for Isotope Data] 85 At Astatine 210 Atomic Number: 85 Atomic Weight: 210 Melting Point: 575 K (302°C or 576°F) Boiling Point: Unknown Density: about 7 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Semi-metal Period Number: 6 Group Number: 17 Group Name: Halogen Radioactive What's in a name? From the Greek word for unstable, astatos. Say what? Astatine is pronounced as AS-teh-teen or as AS-teh-ten. History and Uses: Astatine was produced by Dale R. Carson, K.R. MacKenzie and Emilio Segrè by bombarding an isotope of bismuth, bismuth-209, with alpha particles that had been accelerated in a device called a cyclotron. This created

411

It's Elemental - The Element Gadolinium  

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Europium Europium Previous Element (Europium) The Periodic Table of Elements Next Element (Terbium) Terbium The Element Gadolinium [Click for Isotope Data] 64 Gd Gadolinium 157.25 Atomic Number: 64 Atomic Weight: 157.25 Melting Point: 1586 K (1313°C or 2395°F) Boiling Point: 3546 K (3273°C or 5923°F) Density: 7.90 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 6 Group Number: none Group Name: Lanthanide What's in a name? Named for the mineral gadolinite which was named after Johan Gadolin, a Finnish chemist. Say what? Gadolinium is pronounced as GAD-oh-LIN-ee-em. History and Uses: Spectroscopic evidence for the existence of gadolinium was first observed by the Swiss chemist Jean Charles Galissard de Marignac in the minerals

412

It's Elemental - The Element Mercury  

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Gold Gold Previous Element (Gold) The Periodic Table of Elements Next Element (Thallium) Thallium The Element Mercury [Click for Isotope Data] 80 Hg Mercury 200.59 Atomic Number: 80 Atomic Weight: 200.59 Melting Point: 234.32 K (-38.83°C or -37.89°F) Boiling Point: 629.88 K (356.73°C or 674.11°F) Density: 13.5336 grams per cubic centimeter Phase at Room Temperature: Liquid Element Classification: Metal Period Number: 6 Group Number: 12 Group Name: none What's in a name? Named after the planet Mercury. Mercury's chemical symbol comes from the Greek word hydrargyrum, which means "liquid silver." Say what? Mercury is pronounced as MER-kyoo-ree. History and Uses: Mercury was known to the ancient Chinese and Hindus and has been found in 3500 year old Egyptian tombs. Mercury is not usually found free in nature

413

It's Elemental - The Element Boron  

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Beryllium Beryllium Previous Element (Beryllium) The Periodic Table of Elements Next Element (Carbon) Carbon The Element Boron [Click for Isotope Data] 5 B Boron 10.811 Atomic Number: 5 Atomic Weight: 10.811 Melting Point: 2348 K (2075°C or 3767°F) Boiling Point: 4273 K (4000°C or 7232°F) Density: 2.37 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Semi-metal Period Number: 2 Group Number: 13 Group Name: none What's in a name? From the Arabic word Buraq and the Persian word Burah, which are both words for the material "borax." Say what? Boron is pronounced as BO-ron. History and Uses: Boron was discovered by Joseph-Louis Gay-Lussac and Louis-Jaques Thénard, French chemists, and independently by Sir Humphry Davy, an English chemist,

414

It's Elemental - The Element Thorium  

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Actinium Actinium Previous Element (Actinium) The Periodic Table of Elements Next Element (Protactinium) Protactinium The Element Thorium [Click for Isotope Data] 90 Th Thorium 232.03806 Atomic Number: 90 Atomic Weight: 232.03806 Melting Point: 2023 K (1750°C or 3182°F) Boiling Point: 5061 K (4788°C or 8650°F) Density: 11.72 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 7 Group Number: none Group Name: Actinide Radioactive What's in a name? Named for the Scandinavian god of war, Thor. Say what? Thorium is pronounced as THOR-ee-em or as THO-ree-em. History and Uses: Thorium was discovered by Jöns Jacob Berzelius, a Swedish chemist, in 1828. He discovered it in a sample of a mineral that was given to him by the Reverend Has Morten Thrane Esmark, who suspected that it contained an

415

It's Elemental - The Element Chromium  

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Vanadium Vanadium Previous Element (Vanadium) The Periodic Table of Elements Next Element (Manganese) Manganese The Element Chromium [Click for Isotope Data] 24 Cr Chromium 51.9961 Atomic Number: 24 Atomic Weight: 51.9961 Melting Point: 2180 K (1907°C or 3465°F) Boiling Point: 2944 K (2671°C or 4840°F) Density: 7.15 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 4 Group Number: 6 Group Name: none What's in a name? From the Greek word for color, chroma. Say what? Chromium is pronounced as KROH-mee-em. History and Uses: Chromium was discovered by Louis-Nicholas Vauquelin while experimenting with a material known as Siberian red lead, also known as the mineral crocoite (PbCrO4), in 1797. He produced chromium oxide (CrO3) by mixing

416

It's Elemental - The Element Iron  

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Manganese Manganese Previous Element (Manganese) The Periodic Table of Elements Next Element (Cobalt) Cobalt The Element Iron [Click for Isotope Data] 26 Fe Iron 55.845 Atomic Number: 26 Atomic Weight: 55.845 Melting Point: 1811 K (1538°C or 2800°F) Boiling Point: 3134 K (2861°C or 5182°F) Density: 7.874 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 4 Group Number: 8 Group Name: none What's in a name? From the Anglo-Saxon word iron. Iron's chemical symbol comes from the Latin word for iron, ferrum. Say what? Iron is pronounced as EYE-ern. History and Uses: Archaeological evidence suggests that people have been using iron for at least 5000 years. Iron is the cheapest and one of the most abundant of all metals, comprising nearly 5.6% of the earth's crust and nearly all of the

417

It's Elemental - The Element Molybdenum  

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Niobium Niobium Previous Element (Niobium) The Periodic Table of Elements Next Element (Technetium) Technetium The Element Molybdenum [Click for Isotope Data] 42 Mo Molybdenum 95.96 Atomic Number: 42 Atomic Weight: 95.96 Melting Point: 2896 K (2623°C or 4753°F) Boiling Point: 4912 K (4639°C or 8382°F) Density: 10.2 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 5 Group Number: 6 Group Name: none What's in a name? From the Greek word for lead, molybdos. Say what? Molybdenum is pronounced as meh-LIB-deh-nem. History and Uses: Molybdenum was discovered by Carl Welhelm Scheele, a Swedish chemist, in 1778 in a mineral known as molybdenite (MoS2) which had been confused as a lead compound. Molybdenum was isolated by Peter Jacob Hjelm in 1781. Today,

418

It's Elemental - The Element Cesium  

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Xenon Xenon Previous Element (Xenon) The Periodic Table of Elements Next Element (Barium) Barium The Element Cesium [Click for Isotope Data] 55 Cs Cesium 132.9054519 Atomic Number: 55 Atomic Weight: 132.9054519 Melting Point: 301.59 K (28.44°C or 83.19°F) Boiling Point: 944 K (671°C or 1240°F) Density: 1.93 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 6 Group Number: 1 Group Name: Alkali Metal What's in a name? From the Latin word for sky blue, caesius. Say what? Cesium is pronounced as SEE-zee-em. History and Uses: Cesium was discovered by Robert Wilhelm Bunsen and Gustav Robert Kirchhoff, German chemists, in 1860 through the spectroscopic analysis of Durkheim mineral water. They named cesium after the blue lines they observed in its

419

It's Elemental - The Element Iridium  

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Osmium Osmium Previous Element (Osmium) The Periodic Table of Elements Next Element (Platinum) Platinum The Element Iridium [Click for Isotope Data] 77 Ir Iridium 192.217 Atomic Number: 77 Atomic Weight: 192.217 Melting Point: 2719 K (2446°C or 4435°F) Boiling Point: 4701 K (4428°C or 8002°F) Density: 22.42 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 6 Group Number: 9 Group Name: none What's in a name? From the Latin word for rainbow, iris. Say what? Iridium is pronounced as i-RID-ee-em. History and Uses: Iridium and osmium were discovered at the same time by the British chemist Smithson Tennant in 1803. Iridium and osmium were identified in the black residue remaining after dissolving platinum ore with aqua regia, a mixture

420

It's Elemental - The Element Platinum  

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Iridium Iridium Previous Element (Iridium) The Periodic Table of Elements Next Element (Gold) Gold The Element Platinum [Click for Isotope Data] 78 Pt Platinum 195.084 Atomic Number: 78 Atomic Weight: 195.084 Melting Point: 2041.55 K (1768.4°C or 3215.1°F) Boiling Point: 4098 K (3825°C or 6917°F) Density: 21.46 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 6 Group Number: 10 Group Name: none What's in a name? From the Spainsh word for silver, platina. Say what? Platinum is pronounced as PLAT-en-em. History and Uses: Used by the pre-Columbian Indians of South America, platinum wasn't noticed by western scientists until 1735. Platinum can occur free in nature and is sometimes found in deposits of gold-bearing sands, primarily those found in

Note: This page contains sample records for the topic "finite element method" 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

It's Elemental - The Element Arsenic  

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Germanium Germanium Previous Element (Germanium) The Periodic Table of Elements Next Element (Selenium) Selenium The Element Arsenic [Click for Isotope Data] 33 As Arsenic 74.92160 Atomic Number: 33 Atomic Weight: 74.92160 Melting Point: 1090 K (817°C or 1503°F) Boiling Point: 887 K (614°C or 1137°F) Density: 5.776 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Semi-metal Period Number: 4 Group Number: 15 Group Name: Pnictogen What's in a name? From the Latin word arsenicum, the Greek word arsenikon and the Arabic word Az-zernikh. Say what? Arsenic is pronounced as AR-s'n-ik. History and Uses: Although arsenic compounds were mined by the early Chinese, Greek and Egyptian civilizations, it is believed that arsenic itself was first identified by Albertus Magnus, a German alchemist, in 1250. Arsenic occurs

422

It's Elemental - The Element Barium  

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Cesium Cesium Previous Element (Cesium) The Periodic Table of Elements Next Element (Lanthanum) Lanthanum The Element Barium [Click for Isotope Data] 56 Ba Barium 137.327 Atomic Number: 56 Atomic Weight: 137.327 Melting Point: 1000 K (727°C or 1341°F) Boiling Point: 2170 K (1897°C or 3447°F) Density: 3.62 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 6 Group Number: 2 Group Name: Alkaline Earth Metal What's in a name? From the Greek word for heavy, barys. Say what? Barium is pronounced as BAR-ee-em. History and Uses: Barium was first isolated by Sir Humphry Davy, an English chemist, in 1808 through the electrolysis of molten baryta (BaO). Barium is never found free in nature since it reacts with oxygen in the air, forming barium oxide

423

It's Elemental - The Element Gold  

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

Platinum Platinum Previous Element (Platinum) The Periodic Table of Elements Next Element (Mercury) Mercury The Element Gold [Click for Isotope Data] 79 Au Gold 196.966569 Atomic Number: 79 Atomic Weight: 196.966569 Melting Point: 1337.33 K (1064.18°C or 1947.52°F) Boiling Point: 3129 K (2856°C or 5173°F) Density: 19.282 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 6 Group Number: 11 Group Name: none What's in a name? From the Sanskrit word Jval and the Anglo-Saxon word gold. Gold's chemical symbol comes from the the latin word for gold, aurum. Say what? Gold is pronounced as GOLD. History and Uses: An attractive and highly valued metal, gold has been known for at least 5500 years. Gold is sometimes found free in nature but it is usually found

424

It's Elemental - The Element Rhenium  

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

Tungsten Tungsten Previous Element (Tungsten) The Periodic Table of Elements Next Element (Osmium) Osmium The Element Rhenium [Click for Isotope Data] 75 Re Rhenium 186.207 Atomic Number: 75 Atomic Weight: 186.207 Melting Point: 3459 K (3186°C or 5767°F) Boiling Point: 5869 K (5596°C or 10105°F) Density: 20.8 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 6 Group Number: 7 Group Name: none What's in a name? From the Latin word for the Rhine River, Rhenus. Say what? Rhenium is pronounced as REE-nee-em. History and Uses: Rhenium was discovered by the German chemists Ida Tacke-Noddack, Walter Noddack and Otto Carl Berg in 1925. They detected rhenium spectroscopically in platinum ores and in the minerals columbite ((Fe, Mn, Mg)(Nb, Ta)2O6),

425

It's Elemental - The Element Osmium  

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

Rhenium Rhenium Previous Element (Rhenium) The Periodic Table of Elements Next Element (Iridium) Iridium The Element Osmium [Click for Isotope Data] 76 Os Osmium 190.23 Atomic Number: 76 Atomic Weight: 190.23 Melting Point: 3306 K (3033°C or 5491°F) Boiling Point: 5285 K (5012°C or 9054°F) Density: 22.57 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 6 Group Number: 8 Group Name: none What's in a name? From the Greek word for a smell, osme. Say what? Osmium is pronounced as OZ-mee-em. History and Uses: Osmium and iridium were discovered at the same time by the British chemist Smithson Tennant in 1803. Osmium and iridium were identified in the black residue remaining after dissolving platinum ore with aqua regia, a mixture

426

It's Elemental - The Element Antimony  

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

Tin Tin Previous Element (Tin) The Periodic Table of Elements Next Element (Tellurium) Tellurium The Element Antimony [Click for Isotope Data] 51 Sb Antimony 121.760 Atomic Number: 51 Atomic Weight: 121.760 Melting Point: 903.78 K (630.63°C or 1167.13°F) Boiling Point: 1860 K (1587°C or 2889°F) Density: 6.685 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Semi-metal Period Number: 5 Group Number: 15 Group Name: Pnictogen What's in a name? From the Greek words anti and monos, which together mean "not alone." Antimony's chemical symbol comes from its historic name, Stibium. Say what? Antimony is pronounced as AN-the-MOH-nee. History and Uses: Antimony has been known since ancient times. It is sometimes found free in nature, but is usually obtained from the ores stibnite (Sb2S3) and

427

Three-dimensional seismic tomography with tetrahedra element on isoparametric mapping  

Science Journals Connector (OSTI)

The author has developed a method of three-dimensional seismic tomography on concrete structures. This method is based on ray-trace and identification technique, and the distribution of slowness or energy dissipation is identified based on simultaneously iterative reconstruction technique (SIRT) or the other kind of statistical identification technique. This kind of technique was originally developed for investigation of underground that is called geotomography, however, this technique was difficult to apply to concrete structures because the structures generally have irregular shape. A hexahedral element was implemented by the author to overcome this difficulty based on the idea of isoparametric mapping of hexahedral element on finite element analysis, however, it is still difficult to apply the method to the structures that have highly irregular shape. In this respect, an implementation of tetrahedral element is proposed for the three-dimensional seismic tomography on concrete structures to solve the difficulty in this paper. This implementation is based on the idea of isoparametric mapping as well as the case of hexahedral element and it enables to apply the method to structures of complex shape that is insufficient to represent by hexahedral elements. The validity of the proposed method is checked by some numerical example.

Yoshikazu Kobayashi

2012-01-01T23:59:59.000Z

428

INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN FLUIDS Int. J. Numer. Meth. Fluids 2004; 00:16 Prepared using fldauth.cls [Version: 2002/09/18 v1.01  

E-Print Network [OSTI]

John Wiley & Sons, Ltd. KEY WORDS: Finite element method; free-surface flow; surface tension; dynamic and stability of free surfaces provides one of the major incentives for their mathematical and computational with the chosen elements (this is of particular significance when surface-tension effects are dominant), and

Jimack, Peter

429

It's Elemental - The Element Zinc  

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

Copper Copper Previous Element (Copper) The Periodic Table of Elements Next Element (Gallium) Gallium The Element Zinc [Click for Isotope Data] 30 Zn Zinc 65.38 Atomic Number: 30 Atomic Weight: 65.38 Melting Point: 692.68 K (419.53°C or 787.15°F) Boiling Point: 1180 K (907°C or 1665°F) Density: 7.134 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 4 Group Number: 12 Group Name: none What's in a name? From the German word zink. Say what? Zinc is pronounced as ZINK. History and Uses: Although zinc compounds have been used for at least 2,500 years in the production of brass, zinc wasn't recognized as a distinct element until much later. Metallic zinc was first produced in India sometime in the 1400s by heating the mineral calamine (ZnCO3) with wool. Zinc was rediscovered by

430

It's Elemental - The Element Chlorine  

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

Sulfur Sulfur Previous Element (Sulfur) The Periodic Table of Elements Next Element (Argon) Argon The Element Chlorine [Click for Isotope Data] 17 Cl Chlorine 35.453 Atomic Number: 17 Atomic Weight: 35.453 Melting Point: 171.65 K (-101.5°C or -150.7°F) Boiling Point: 239.11 K (-34.04°C or -29.27°F) Density: 0.003214 grams per cubic centimeter Phase at Room Temperature: Gas Element Classification: Non-metal Period Number: 3 Group Number: 17 Group Name: Halogen What's in a name? From the Greek word for greenish yellow, chloros. Say what? Chlorine is pronounced as KLOR-een or as KLOR-in. History and Uses: Since it combines directly with nearly every element, chlorine is never found free in nature. Chlorine was first produced by Carl Wilhelm Scheele, a Swedish chemist, when he combined the mineral pyrolusite (MnO2) with

431

It's Elemental - The Element Fluorine  

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

Oxygen Oxygen Previous Element (Oxygen) The Periodic Table of Elements Next Element (Neon) Neon The Element Fluorine [Click for Isotope Data] 9 F Fluorine 18.9984032 Atomic Number: 9 Atomic Weight: 18.9984032 Melting Point: 53.53 K (-219.62°C or -363.32°F) Boiling Point: 85.03 K (-188.12°C or -306.62°F) Density: 0.001696 grams per cubic centimeter Phase at Room Temperature: Gas Element Classification: Non-metal Period Number: 2 Group Number: 17 Group Name: Halogen What's in a name? From the Latin and French words for flow, fluere. Say what? Fluorine is pronounced as FLU-eh-reen or as FLU-eh-rin. History and Uses: Fluorine is the most reactive of all elements and no chemical substance is capable of freeing fluorine from any of its compounds. For this reason, fluorine does not occur free in nature and was extremely difficult for

432

It's Elemental - The Element Lead  

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

Thallium Thallium Previous Element (Thallium) The Periodic Table of Elements Next Element (Bismuth) Bismuth The Element Lead [Click for Isotope Data] 82 Pb Lead 207.2 Atomic Number: 82 Atomic Weight: 207.2 Melting Point: 600.61 K (327.46°C or 621.43°F) Boiling Point: 2022 K (1749°C or 3180°F) Density: 11.342 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Metal Period Number: 6 Group Number: 14 Group Name: none What's in a name? From the Anglo-Saxon word lead. Lead's chemical symbol comes from the Latin word for waterworks, plumbum. Say what? Lead is pronounced as LED. History and Uses: Lead has been known since ancient times. It is sometimes found free in nature, but is usually obtained from the ores galena (PbS), anglesite (PbSO4), cerussite (PbCO3) and minum (Pb3O4). Although lead makes up only

433

It's Elemental - The Element Iodine  

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

Tellurium Tellurium Previous Element (Tellurium) The Periodic Table of Elements Next Element (Xenon) Xenon The Element Iodine [Click for Isotope Data] 53 I Iodine 126.90447 Atomic Number: 53 Atomic Weight: 126.90447 Melting Point: 386.85 K (113.7°C or 236.7°F) Boiling Point: 457.55 K (184.4°C or 364.0°F) Density: 4.93 grams per cubic centimeter Phase at Room Temperature: Solid Element Classification: Non-metal Period Number: 5 Group Number: 17 Group Name: Halogen What's in a name? From the Greek word for violet, iodes. Say what? Iodine is pronounced as EYE-eh-dine or as EYE-eh-din. History and Uses: Iodine was discovered by the French chemist Barnard Courtois in 1811. Courtois was extracting sodium and potassium compounds from seaweed ash. Once these compounds were removed, he added sulfuric acid (H2SO4) to

434

A Method to Increase Current Density in a Mono Element Internal Tin Processed Superconductor Utilizing Zr Oxide to Refine Grain Size  

SciTech Connect (OSTI)

The effect of Oxygen on (Nb1Zr)3Sn multifilament conductors manufactured by the Mono Element Internal Tin (MEIT) process was explored to improve the current density by refining the grain size. This followed work first done by General Electric on the Nb3Sn tape process. Techniques to fabricate the more difficult Nb1Zr composites are described and allowed fabrication of long lengths of .254 mm diameter wire from an 88.9 mm diameter billet. Oxygen was incorporated through the use of SnO2 mixed with tin powder and incorporated into the core. These were compared to samples with Ti+Sn and Cu+Sn cores. Heat treatments covered the range of 700 C to 1000 C. Current density vs. H, grain size, and reaction percentages are provided for the materials tested. The Oxygen gave superior results in the temperature range of 815-1000 C. It also stabilized the filament geometry of the array in comparison to the other additions at the higher temperatures. At 815 C a peak in layer Jc yielded values of 2537 A/mm2 at 12 T and 1353 A/mm2 at 15T, 8-22% and 30-73% greater respectively than 700 C values. Results with Oxygen at high temperature show the possibility of high speed continuous reaction of the composite versus the current batch or react in place methods. In general the Ti additions gave superior results at the lower reaction temperature. Future work is suggested to determine if the 815 C reaction temperature can lead to higher current density in high tin (Nb1Zr+Ox)3Sn conductors. A second technique incorporated oxygen directly into the Nb1Zr rods through heat treatment with Nb2O5 at 1100 C for 100 hours in vacuum prior to extrusion. The majority of the filaments reduced properly in the composite but some local variations in hardness led to breakage at smaller diameters.

Bruce A. Zeitlin, Eric Gregory

2008-04-07T23:59:59.000Z

435

An outgoing energy flux boundary condition for finite difference ICRP antenna models  

SciTech Connect (OSTI)

For antennas at the ion cyclotron range of frequencies (ICRF) modeling in vacuum can now be carried out to a high level of detail such that shaping of the current straps, isolating septa, and discrete Faraday shield structures can be included. An efficient approach would be to solve for the fields in the vacuum region near the antenna in three dimensions by finite methods and to match this solution at the plasma-vacuum interface to a solution obtained in the plasma region in one dimension by Fourier methods. This approach has been difficult to carry out because boundary conditions must be imposed at the edge of the finite difference grid on a point-by-point basis, whereas the condition for outgoing energy flux into the plasma is known only in terms of the Fourier transform of the plasma fields. A technique is presented by which a boundary condition can be imposed on the computational grid of a three-dimensional finite difference, or finite element, code by constraining the discrete Fourier transform of the fields at the boundary points to satisfy an outgoing energy flux condition appropriate for the plasma. The boundary condition at a specific grid point appears as a coupling to other grid points on the boundary, with weighting determined by a kemel calctdated from the plasma surface impedance matrix for the various plasma Fourier modes. This boundary condition has been implemented in a finite difference solution of a simple problem in two dimensions, which can also be solved directly by Fourier transformation. Results are presented, and it is shown that the proposed boundary condition does enforce outgoing energy flux and yields the same solution as is obtained by Fourier methods.

Batchelor, D.B.; Carter, M.D.

1992-11-01T23:59:59.000Z

436

Lattice Boltzmann method on irregular meshes  

Science Journals Connector (OSTI)

A finite-volume scheme for the lattice Boltzmann method (FVLBM) is described. The scheme uses a finite-volume formulation based on triangular elements in two dimensions and is implemented assuming that velocity space is isotropically discretized at each node in position space. The accuracy of the finite-volume scheme is numerically demonstrated by comparing the computed macroscopic velocity field with the exact solution of the Navier-Stokes equations for the flow of an incompressible fluid between two relatively rotating cylinders. The FVLBM scheme is applicable to irregular two-dimensional regions which contain both exterior and interior boundaries of arbitrary shape. Thus, the range of applicability of systems to which the FVLBM may be applied is seen to be significantly extended.

Gongwen Peng; Haowen Xi; Comer Duncan; So-Hsiang Chou

1998-10-01T23:59:59.000Z

437

Finite element modeling of SHTE and PSVTM electroseismics  

E-Print Network [OSTI]

ties of the presented methodology to detect gas (oil) saturated thin layers are shown. ... In geophysical exploration, the electro-osmosis phenomenon is known as .... between electromagnetic and mechanical processes is represented in the above ...... developments suggest viable applications in exploration and production.

zyserman

438

One dimensional electroseismic modeling using the finite element ...  

E-Print Network [OSTI]

The symbols ?i,j, i=b,t, j=B,M denote the bottom and top boundaries, ...... suggest viable applications in exploration and production”, 75th SEG Annual Meeting,.

2013-01-30T23:59:59.000Z

439

A Comparison of Iterative Multilevel Finite Element Solvers  

E-Print Network [OSTI]

de Janeiro, RJ 21945­970, Brazil Abstract A comparison is made of two iterative algorithms on the energy variation of the incremental correction through the iterative process, which seems to be a more of choice. The increasing computing power reached with vector and parallel computers has renewed

Coutinho, Alvaro L. G. A.

440

Least-squares finite elements and constrained evolution systems  

E-Print Network [OSTI]

in?nitesimal) generator of T is the linear operator A : D(and Generators Let X be a Banach space with norm X , A : D(A) ? X ? X be a lineara linear operator. Then, A is the in?nitesimal generator of

Szypowski, Ryan

2008-01-01T23:59:59.000Z

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


441

Finite Element Modeling of the Fastening Systems and the Concrete  

E-Print Network [OSTI]

Sleeper and Ballast 0 500 1000 1500 2000 2500 3000 3500 4000 0.0000 0.0002 0.0004 0.0006 0.0008 0 of strands Rail seat area is between 0.39 m to 0.67 m Rail Seat Area Component Modeling: Concrete Sleeper Seat Area Position of concrete surface strain lt = 0.48 m Component Modeling: Concrete Sleeper

Barkan, Christopher P.L.

442

Computational wind engineering using finite element package ADINA  

E-Print Network [OSTI]

Design of tall and long span structures is governed by the wind forces. Inadequate research in the field of wind dynamics has forced engineers to rely on design codes or wind tunnel tests for sufficient data. The present ...

Bajoria, Ankur

2008-01-01T23:59:59.000Z

443

FINITE ELEMENT ANALYSIS OF STEEL WELDED COVERPLATE INCLUDING COMPOSITE DOUBLERS  

E-Print Network [OSTI]

With the increasing focus on welded bridge members resulting in crack initiation and propagation, there is a large demand for creative solutions. One of these solutions includes the application of composite doublers over the critical weld. In order...

Petri, Brad

2008-05-15T23:59:59.000Z

444

Finite element based inversion for time-harmonic electromagnetic problems  

Science Journals Connector (OSTI)

......water scenario. In shallow water the air wave dominates the...recovered as well as in our deep water study which can be seen as...A Quality Tetrahedral Mesh Generator and 3D Delaunay Triangulator...Department of Earth, Ocean and Atmospheric Sciences Vancouver, BC Canada......

Christoph Schwarzbach; Eldad Haber

2013-01-01T23:59:59.000Z

445

Parallel Adaptive Finite Element Software for Semiconductor Device Simulation*  

E-Print Network [OSTI]

.9 million grid problem run on the Intel Delta machine achieved 20% efficiency using 512 nodes and con was created. Quad­ and oct­tree utilities were developed and used to support the gridding of complex IC are computationally demanding and to date the infrastructure to support large scale 3D models has been insufficient

Dutton, Robert W.

446

A Mixed Finite Element Framework for Modeling Coupled Fluid Flow ...  

E-Print Network [OSTI]

such as recovery from compaction drive, waterflooding, surface subsidence, seal in- tegrity ...... and for rocks and concrete it is in the range of 0.4-0.6. ...... incorporate into the programs an automatic, self-adaptive, procedure which adjusts.

Birendra Jha

2005-10-03T23:59:59.000Z

447

Finite Element Analysis of Three-Phase Piezoelectric Nanocomposites  

E-Print Network [OSTI]

on performance. The nanocomposite consisted of a polyimide matrix, beta-CN APB/ODPA, enhanced with single wall carbon nanotubes and PZT-5A particles. The polyimide and nan- otube phases were modeled as a single homogenized phase. This results in a two...

Maxwell, Kevin S.

2010-10-12T23:59:59.000Z

448

Finite element analysis of a coiled composite tubular  

E-Print Network [OSTI]

This study presents the design and stress analysis of a composite tubular that can be coiled onto large spools for ease of storage and installation on offshore platforms. The tube is analyzed under working pressure and tensile loads, as well...

Judice, David Roy

2012-06-07T23:59:59.000Z

449

Finite element modeling of hydraulic fracturing in 3D  

E-Print Network [OSTI]

Mar 22, 2013 ... Two examples of hydraulic fracturing are given. when the pressure buildup ... Hydraulic fracturing is the coupled dynamics of frac- ture and ?uid ...

2013-03-22T23:59:59.000Z

450

Finite-element modelling: a new tool for the biologist  

Science Journals Connector (OSTI)

...distributed computing 1. Introduction Car manufacturers do not destroy thousands...be used to either replace their defective counterparts or to perform entirely...application is in the design of car crash- worthiness. Cars must both protect the occupants...

2000-01-01T23:59:59.000Z

451

Heat Transport in Groundwater Systems--Finite Element Model  

E-Print Network [OSTI]

into groundwater aquifers for long term energy storage. Analytical solutions are available that predict water temperatures as hot water is injected into a groundwater aquifer, but little field and laboratory data are available to verify these models. The objectives...

Grubaugh, E. K.; Reddell, D. L.

452

Rayleigh's Principle in Finite Element Calculations of Seismic Wave Response  

Science Journals Connector (OSTI)

......of Seismic Wave Response Warwick D. Smith...resulting error in frequency is of second order...conserve computer storage for large models...estimatesof the seismic response of irregular Earth...complex one, and this frequency is then accurate...to the potential energy and the denominator......

Warwick D. Smith; Bruce A. Bolt

1958-12-01T23:59:59.000Z

453

Rayleigh's Principle in Finite Element Calculations of Seismic Wave Response  

Science Journals Connector (OSTI)

......resulting error in frequency is of second order...conserve computer storage for large models...of Seismic Wave Response Warwick D. Smith...resulting error in frequency is of second order...conserve computer storage for large models...potential and kinetic energies of the system in......

Warwick D. Smith; Bruce A. Bolt

1976-06-01T23:59:59.000Z

454

Finite Element Studies of Colloidal Mixtures Influenced by Electric Fields  

E-Print Network [OSTI]

A further understanding of colloidal mixture behavior under applied electric fields would greatly benefit the design of smart material systems such as electrorheological fluidic devices and microfluidic reconfigurable antennas. This thesis presents...

Drummond, Franklin Jerrel

2011-10-21T23:59:59.000Z

455

Blank optimization in sheet metal forming using finite element simulation  

E-Print Network [OSTI]

The present study aims to determine the optimum blank shape design for the deep drawing of arbitrary shaped cups with a uniform trimming allowance at the flange i.e. cups without ears. This earing defect is caused by planar anisotropy in the sheet...

Goel, Amit

2006-04-12T23:59:59.000Z

456

THERMAL PROPERTY PREDICTION VIA FINITE-ELEMENT SIMULATIONS  

E-Print Network [OSTI]

of gas turbine parts Ã? Optimization of k during TBC material development Ã? New lower k TBC materials properties are difficult, costly, and time-consuming to measure directly, an alternate strategy is to develop development Ã? used sparingly by turbine part designers Ã? typically not included in production qualification

Fuller, Edwin R.

457

Experimental validation of finite element codes for welding deformations  

E-Print Network [OSTI]

Institute for Energy Technology, N-2027 Kjeller, Norway. Abstract A single pass Metal Inert Gas welding. Hamidec , H. G. Fjærd , A. Moa , M. Belletc a SINTEF Materials Technology, N-0314 Oslo, Norway. b University of Oslo, N-0316 Oslo, Norway. c CEMEF Ecole des Mines de Paris, Sophia Antipolis, France. d

Boyer, Edmond

458

Parallel finite element modeling of earthquake ground response and liquefaction  

E-Print Network [OSTI]

Machines Corporation (IBM). Arduino, P. , Kramer, S. , and2000; Shao and Desai 2000; Arduino et al. 2001). Currently,

Lu, Jinchi

2006-01-01T23:59:59.000Z

459

Stochastic Finite Element Framework for Cardiac Kinematics Function  

E-Print Network [OSTI]

Pengcheng Shi and Huafeng Liu Biomedical Research Laboratory Department of Electrical and Electronic Engineering Hong Kong University of Science and Technology Clear Water Bay, Kowloon, Hong Kong {pengcheng

Shi, Pengcheng

460

The Finite Element Analusis of Ventilative Motorcycle Helmets.  

E-Print Network [OSTI]

??In Taiwan, a motorcycle is the most important and general transportation. It is no denying that wearing a motorcycle helmet could prevent the rider from… (more)

Shen, Jhuo-ying

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" 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

Finite Volume Methods and their Analysis  

Science Journals Connector (OSTI)

......rectangular mesh. Then the residual over a typical quadrilateral...the approximation, the residual reduces to the simple...of an ideal, inviscid gas take the form (2.1...through two-dimensional gas turbine cascades. ASME paper......

K. W. MORTON; E. SULI

1991-04-01T23:59:59.000Z

462

Quantum Mechanics associated with a Finite Group  

E-Print Network [OSTI]

I describe, in the simplified context of finite groups and their representations, a mathematical model for a physical system that contains both its quantum and classical aspects. The physically observable system is associated with the space containing elements fxf for f an element in the regular representation of a given finite group G. The Hermitian portion of fxf is the Wigner distribution of f whose convolution with a test function leads to a mathematical description of the quantum measurement process. Starting with the Jacobi group that is formed from the semidirect product of the Heisenberg group with its automorphism group SL(2,F{N}) for N an odd prime number I show that the classical phase space is the first order term in a series of subspaces of the Hermitian portion of fxf that are stable under SL(2,F{N}). I define a derivative that is analogous to a pseudodifferential operator to enable a treatment that parallels the continuum case. I give a new derivation of the Schrodinger-Weil representation of the Jacobi group. Keywords: quantum mechanics, finite group, metaplectic. PACS: 03.65.Fd; 02.10.De; 03.65.Ta.

Robert W. Johnson

2006-04-20T23:59:59.000Z

463

Relationships of important elements of the student teaching experience and methods of student teaching placement to the quality of experience of student teachers  

E-Print Network [OSTI]

educator respondents indicated that the number one placement practice for placing student teachers was that of the cooperating teacher having at least three years teaching experience (mean = 4.61). Teacher educator respondents indicated that a... cooperating center having access to the World Wide Web (mean = 4.79) was the most important element of a cooperating center. Additionally, teacher educators indicated that a cooperating teacher who iv supports other school activities was the most...

Morrish, Douglas Glenn

2004-09-30T23:59:59.000Z

464

This paper appears (edited in form only) in Computer Methods in Biomechanics and Biomedical Engineering (Taylor and Francis  

E-Print Network [OSTI]

to a particular simulation method in the interest of focusing on automation of model preparation (rather than), prohibiting manual intervention in the model preparation process. This paper provides a pipeline for rapid (preparing solid meshes from surface models), automated calibration of models to finite element reference

Salisbury, Kenneth

465

Finite generation conjectures for cohomology over finite fields.  

E-Print Network [OSTI]

We construct an intermediate cohmology between motivic cohomology and Weil-etale cohomology. Using this, the Bass conjecture on finite generation of motivic cohomology, and the Beilinson-Tate on the finite generation of Weil-etale cohomology are related.

Thomas H Geisser

466

Finite volume renormalization scheme for fermionic operators  

SciTech Connect (OSTI)

We propose a new finite volume renormalization scheme. Our scheme is based on the Gradient Flow applied to both fermion and gauge fields and, much like the Schr\\"odinger functional method, allows for a nonperturbative determination of the scale dependence of operators using a step-scaling approach. We give some preliminary results for the pseudo-scalar density in the quenched approximation.

Monahan, Christopher; Orginos, Kostas [JLAB

2013-11-01T23:59:59.000Z

467

A MIXED FINITE ELEMENT--FINITE VOLUME FORMULATION OF THE BLACKOIL MODEL #  

E-Print Network [OSTI]

three independent components (oil, gas, and water) form the three phases (liquid, vapor, and aqua. The two chemical components, oil and gas, represent ideal mean hydrocarbons. At standard pressure and temperature (``stock­tank'' conditions or STC), the ``oil'' hydrocarbon will be present in the liquid phase

Bergamaschi, Luca

468

Comparasion of finite difference and finite element hydrodynamic models applied to the Laguna Madre Estuary, Texas  

E-Print Network [OSTI]

Station. Calibrated Velocity at the Humble Channd Station. . Calibrated Vdocity at the GIWW at JFK Causeway Station . . Calibrated Velocity at the GIWW Marker 199 Station. Calibrated Velocity at the North of Bagm Bay Station. Calibrated Velocity... Station. . . . . . . . . . Comparison of Velocity at the Humble Channel Station . Page 63 63 67 67 67 68 68 71 71 71 72 72 72 73 73 74 79 80 82 82 82 83 83 &3 LIST OF FIGURES - continued 61 62 63 65 66 67 68 Comparison...

McArthur, Karl Edward

2012-06-07T23:59:59.000Z

469

Finite generators for countable group actions; Finite index pairs of equivalence relations; Complexity measures for recursive programs  

E-Print Network [OSTI]

Finite generators on comeagerconnections with finite generators and finitely additive30 Constructing finite generators using i-traveling

Tserunyan, Anush

2013-01-01T23:59:59.000Z

470

Numerical Simulation of Liquid-Solid, Solid-Liquid Phase Change Using Finite Element Method in h,p,k Framework with Space-Time Variationally Consistent Integral Forms  

E-Print Network [OSTI]

: cp@T@t r (krTs) = 0 8(x;t) 2 sxt = sx t = sx (0; ) (2.1) Liquid Phase: cp@T@t r (krTl) = 0 8(x;t) 2 lxt = lx t = lx (0; ) (2.2) At the interface: Lfvn = [( krTs) ( krTl)] n 8(x;t) 2 x;t = x t (2.3) 10 in which sx and lx are solid... and liquid spatial domains, x(t) = sxT lx is the interface between the two phases, Lf is the latent heat of fusion,n is the unit exterior normal from the solid phase at the interface, and vn is the normal velocity of the interface. Subscripts s and l...

Truex, Michael

2010-07-21T23:59:59.000Z

471

Numerical Methods of Computational Electromagnetics for Complex Inhomogeneous Systems  

SciTech Connect (OSTI)

Understanding electromagnetic phenomena is the key in many scientific investigation and engineering designs such as solar cell designs, studying biological ion channels for diseases, and creating clean fusion energies, among other things. The objectives of the project are to develop high order numerical methods to simulate evanescent electromagnetic waves occurring in plasmon solar cells and biological ion-channels, where local field enhancement within random media in the former and long range electrostatic interactions in the latter are of major challenges for accurate and efficient numerical computations. We have accomplished these objectives by developing high order numerical methods for solving Maxwell equations such as high order finite element basis for discontinuous Galerkin methods, well-conditioned Nedelec edge element method, divergence free finite element basis for MHD, and fast integral equation methods for layered media. These methods can be used to model the complex local field enhancement in plasmon solar cells. On the other hand, to treat long range electrostatic interaction in ion channels, we have developed image charge based method for a hybrid model in combining atomistic electrostatics and continuum Poisson-Boltzmann electrostatics. Such a hybrid model will speed up the molecular dynamics simulation of transport in biological ion-channels.

Cai, Wei

2014-05-15T23:59:59.000Z

472

A toolbox for a class of discontinuous Petrov-Galerkin methods using trilinos.  

SciTech Connect (OSTI)

The class of discontinuous Petrov-Galerkin finite element methods (DPG) proposed by L. Demkowicz and J. Gopalakrishnan guarantees the optimality of the solution in an energy norm and produces a symmetric positive definite stiffness matrix, among other desirable properties. In this paper, we describe a toolbox, implemented atop Sandia's Trilinos library, for rapid development of solvers for DPG methods. We use this toolbox to develop solvers for the Poisson and Stokes problems.

Roberts, Nathaniel David (University of Texas at Austin, Austin, TX); Bochev, Pavel Blagoveston; Demkowicz, Leszek D. (University of Texas at Austin, Austin, TX); Ridzal, Denis

2011-09-01T23:59:59.000Z

473

On Finite Index Subgroups of Linear Groups  

Science Journals Connector (OSTI)

......the pro-finite completion of F, is infinite...then every finite index subgroup is of p-power...subgroup T' of finite index in F, a finitely...the pro-finite completion of the ring A...denotes the m-adic completion of A with respect...ON FINITE INDEX SUBGROUPS OF LINEAR......

Alexander Lubotzky

1987-07-01T23:59:59.000Z

474

A finite-patch model of a flexible plate via Kane's dynamics  

Science Journals Connector (OSTI)

Military hardware must undergo extensive shock-response analysis to predict survivability to mechanical shock. Although finite element modelling is commonly used to model such hardware, alternative methods which offer the possibility of shorter modelling, modification, or simulation times continue to be desirable. This research effort applies Kane's dynamics to the problem of plate modelling, toward shock-response analysis of homogeneous plates having various geometries and boundary conditions. Analytical equations of motion are found for a continuous flexible plate that is discretised in checkerboard fashion as a patchwork of rigid rectangular patches connected by flexible springs and damped modally. A MATLAB implementation is used to validate the model against pertinent analytical and numerical benchmark analyses, for a variety of boundary conditions. The model is then reduced by applying non-holonomic constraints directly using Kane's method, and revalidated via MATLAB for a rectangular plate in simple support.

R. David Hampton

2012-01-01T23:59:59.000Z

475

Examination of Granular Material Behavior in a Laminar-type Direct Simple Shear Device using Laboratory Validated Discrete Element Method Simulations  

E-Print Network [OSTI]

4.3.1 Influence of Ring Size on Response . . . . . . 263 4.3.2 Influence of Number of Particles on Response 265 4.3.3 Influence of Interparticle Friction on Response 268 4.4 Additional Studies . . . . . . . . . . . . . . . . . . . 270 4....4.1 Influence of Ring Wall Friction on Response . 270 4.4.2 Influence of DEM Sample Preparation Method on Response 271 4.5 Conclusions . . . . . . . . . . . . . . . . . . . 274 5. VALIDATION AND DISCUSSION OF RESULTS. 275 5.1 Validation of DEM...

Bernhardt, Michelle Lee

2013-08-29T23:59:59.000Z

476

Performance of a Stirling engine regenerator having finite mass  

SciTech Connect (OSTI)

The performance of a Stirling engine regenerator subjected to sinusoidal mass flow rate and pressure variation is analyzed. It is shown that cyclic variations in the temperature of the matrix due to its finite mass lead to an increase in the apparent regenerator effectiveness, but a decrease in engine power. Approximate closed-form expressions for both of these effects are deduced. The results of this analysis are compared with the predictions of a finite-element system model, and good agreement is found.

Jones, J.D.

1986-10-01T23:59:59.000Z

477

Computer modeling of single-cell and multicell thermionic fuel elements  

SciTech Connect (OSTI)

Modeling efforts are undertaken to perform coupled thermal-hydraulic and thermionic analysis for both single-cell and multicell thermionic fuel elements (TFE). The analysis--and the resulting MCTFE computer code (multicell thermionic fuel element)--is a steady-state finite volume model specifically designed to analyze cylindrical TFEs. It employs an interactive successive overrelaxation solution technique to solve for the temperatures throughout the TFE and a coupled thermionic routine to determine the total TFE performance. The calculated results include temperature distributions in all regions of the TFE, axial interelectrode voltages and current densities, and total TFE electrical output parameters including power, current, and voltage. MCTFE-generated results compare experimental data from the single-cell Topaz-II-type TFE and multicell data from the General Atomics 3H5 TFE to benchmark the accuracy of the code methods.

Dickinson, J.W.; Klein, A.C. [Oregon State Univ., Corvallis, OR (United States). Dept. of Nuclear Engineering

1996-05-01T23:59:59.000Z

478

Elemental and structural analysis of silicon forms in herbal drugs using silicon-29 MAS NMR and WD-XRF spectroscopic methods  

Science Journals Connector (OSTI)

The objective of this work was to study concentration of silicon and its structural forms present in herbal drugs. Equisetum arvense and Urtica dioica L. from teapot bags, dietary supplements (tablets and capsules) containing those herbs, dry extract obtained from a teapot bag of E. arvense, and samples of the latter herb harvested in wild habitat over four months were studied using wavelength dispersive X-ray spectroscopy (WD-XRF) and high-resolution solid-state 29Si NMR. The highest concentration of Si, ca. 27 mg/g, was found in the herbal material from the teapot bags containing E. arvense. The Si content in natural E. arvense (whole plants) increased from May to August by ca. 7 mg/g, reaching value 26 mg/g. Three different silicon forms were detected in the studied herbal samples: Si(OSi)4 (Q4), Si(OH)(OSi)3 (Q3) and Si(OH)2(OSi)2 (Q2). Those sites were populated in E. arvense in the following order: Q4 ? Q3 > Q2. A dramatic, ca. 50-fold decrease of the Si concentration during the infusion process was observed. The infusion process and the subsequent drying procedure augmented population of the Q4 sites at the cost of the Q2 sites. The WD-XRF and 29Si NMR methods occurred useful and complementary in the study of herbal materials.

L. Pajchel; P. Nykiel; W. Kolodziejski

2011-01-01T23:59:59.000Z

479

Finite generation of Tate cohomology.  

E-Print Network [OSTI]

Let G be a finite group and let k be a field of characteristic p. Given a finitely generated indecomposable non-projective kG-module M, we conjecture that if the Tate cohomology $\\HHHH^*(G, M)$ of G with coefficients in M is finitely generated over the Tate cohomology ring $\\HHHH^*(G, k)$, then the support variety V_G(M) of M is equal to the entire maximal ideal spectrum V_G(k). We prove various results which support this conjecture. The converse of this conjecture is established for modules in the connected component of k in the stable Auslander-Reiten quiver for kG, but it is shown to be false in general. It is also shown that all finitely generated kG-modules over a group G have finitely generated Tate cohomology if and only if G has periodic cohomology.

Jon F. Carlson; Sunil K. Chebolu; Jan Minac.; 15 (2011) 244-257

480

Calculating the binding free energies of charged species based on explicit-solvent simulations employing lattice-sum methods: An accurate correction scheme for electrostatic finite-size effects  

SciTech Connect (OSTI)

The calculation of a protein-ligand binding free energy based on molecular dynamics (MD) simulations generally relies on a thermodynamic cycle in which the ligand is alchemically inserted into the system, both in the solvated protein and free in solution. The corresponding ligand-insertion free energies are typically calculated in nanoscale computational boxes simulated under periodic boundary conditions and considering electrostatic interactions defined by a periodic lattice-sum. This is distinct from the ideal bulk situation of a system of macroscopic size simulated under non-periodic boundary conditions with Coulombic electrostatic interactions. This discrepancy results in finite-size effects, which affect primarily the charging component of the insertion free energy, are dependent on the box size, and can be large when the ligand bears a net charge, especially if the protein is charged as well. This article investigates finite-size effects on calculated charging free energies using as a test case the binding of the ligand 2-amino-5-methylthiazole (net charge +1 e) to a mutant form of yeast cytochrome c peroxidase in water. Considering different charge isoforms of the protein (net charges ?5, 0, +3, or +9 e), either in the absence or the presence of neutralizing counter-ions, and sizes of the cubic computational box (edges ranging from 7.42 to 11.02 nm), the potentially large magnitude of finite-size effects on the raw charging free energies (up to 17.1 kJ?mol{sup ?1}) is demonstrated. Two correction schemes are then proposed to eliminate these effects, a numerical and an analytical one. Both schemes are based on a continuum-electrostatics analysis and require performing Poisson-Boltzmann (PB) calculations on the protein-ligand system. While the numerical scheme requires PB calculations under both non-periodic and periodic boundary conditions, the latter at the box size considered in the MD simulations, the analytical scheme only requires three non-periodic PB calculations for a given system, its dependence on the box size being analytical. The latter scheme also provides insight into the physical origin of the finite-size effects. These two schemes also encompass a correction for discrete solvent effects that persists even in the limit of infinite box sizes. Application of either scheme essentially eliminates the size dependence of the corrected charging free energies (maximal deviation of 1.5 kJ?mol{sup ?1}). Because it is simple to apply, the analytical correction scheme offers a general solution to the problem of finite-size effects in free-energy calculations involving charged solutes, as encountered in calculations concerning, e.g., protein-ligand binding, biomolecular association, residue mutation, pK{sub a} and redox potential estimation, substrate transformation, solvation, and solvent-solvent partitioning.

Rocklin, Gabriel J. [Department of Pharmaceutical Chemistry, University of California San Francisco, 1700 4th St., San Francisco, California 94143-2550, USA and Biophysics Graduate Program, University of California San Francisco, 1700 4th St., San Francisco, California 94143-2550 (United States)] [Department of Pharmaceutical Chemistry, University of California San Francisco, 1700 4th St., San Francisco, California 94143-2550, USA and Biophysics Graduate Program, University of California San Francisco, 1700 4th St., San Francisco, California 94143-2550 (United States); Mobley, David L. [Departments of Pharmaceutical Sciences and Chemistry, University of California Irvine, 147 Bison Modular, Building 515, Irvine, California 92697-0001, USA and Department of Chemistry, University of New Orleans, 2000 Lakeshore Drive, New Orleans, Louisiana 70148 (United States)] [Departments of Pharmaceutical Sciences and Chemistry, University of California Irvine, 147 Bison Modular, Building 515, Irvine, California 92697-0001, USA and Department of Chemistry, University of New Orleans, 2000 Lakeshore Drive, New Orleans, Louisiana 70148 (United States); Dill, Ken A. [Laufer Center for Physical and Quantitative Biology, 5252 Stony Brook University, Stony Brook, New York 11794-0001 (United States)] [Laufer Center for Physical and Quantitative Biology, 5252 Stony Brook University, Stony Brook, New York 11794-0001 (United States); Hünenberger, Philippe H., E-mail: phil@igc.phys.chem.ethz.ch [Laboratory of Physical Chemistry, Swiss Federal Institute of Technology, ETH, 8093 Zürich (Switzerland)

2013-11-14T23:59:59.000Z

Note: This page contains sample records for the topic "finite element method" from the National Library of EnergyBeta (NLEBeta).
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481

Area-transformation method for designing invisible cloaks  

Science Journals Connector (OSTI)

By means of area-transformation method the material parameters of the invisible cloaks in elliptic-cylindrical and spherical coordinates were obtained. The material parameters of the invisible cloaks are nonsingular and the cloaks can operate in a wide bandwidth due to the area-transformation rather than the point-transformation. The invisible properties of the cloaks are nearly perfect when the original area is small enough compared with its counterpart in the transformed space. Full wave simulations based on finite element method verified the designed cloaks.

Xinhua Wang; Shaobo Qu; Xiang Wu; Jiafu Wang; Zhuo Xu; Hua Ma

2010-01-01T23:59:59.000Z

482

4. OpenFst: An Open-Source, Weighted Finite-State Transducer Library and its Applications to Speech and Language  

E-Print Network [OSTI]

and Language Michael Riley, Cyril Allauzen, and Martin Jansche, Google Inc. Finite-state methods are well

Tomkins, Andrew

483

A virtual element method with arbitrary regularity  

Science Journals Connector (OSTI)

......Cottrell et al., 2009), but at the cost of using tensor-product meshes or resorting...integer s 0, we define the functional space Bs(P) := {v L2 (P) : v|e Ps(e...was partially supported by the National Nuclear Security Administration of the U.S......

Lourenco Beirão da Veiga; Gianmarco Manzini

2014-04-01T23:59:59.000Z

484

FDM Helmholtz modeling of finite grating and waveguide width effects on resonant subwavelength grating reflectivity.  

SciTech Connect (OSTI)

Resonant subwavelength gratings (RSGs) may be used as narrow-band wavelength and angular reflectors. Rigorous coupled wave analysis (RCWA) predicts 100% reflectivity at the resonant frequency of an incident plane wave from an RSG of infinite extent. For devices of finite extent or for devices illuminated with a finite beam, the peak reflectivity drops, coupled with a broadening of the peak. More complex numerical methods are required to model these finite effects. We have modeled finite devices and finite beams with a two-dimensional finite difference Helmholtz equation. The effect of finite grating aperture and finite beam size are investigated. Specific cases considered include Gaussian beam illumination of an infinite grating, Gaussian illumination of a finite grating, and plane wave illumination of an apertured grating. For a wide grating with a finite Gaussian beam, it is found that the reflectivity is an exponential function of the grating width. Likewise, for an apertured grating the reflectivity shows an exponential decay with narrowing aperture size. Results are compared to other methods, including plane wave decomposition of Gaussian beams using RCWA for the case of a finite input beam, and a semi-analytical techniques for the case of the apertured grating.

Kemme, Shanalyn A.; Peters, David William; Hadley, G. Ronald

2003-07-01T23:59:59.000Z

485

It's Elemental - Isotopes of the Element Magnesium  

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

Sodium Sodium Previous Element (Sodium) The Periodic Table of Elements Next Element (Aluminum) Aluminum Isotopes of the Element Magnesium [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 24 78.99% STABLE 25 10.00% STABLE 26 11.01% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 19 4.0 picoseconds Double Proton Emission 100.00% 20 90.8 milliseconds Electron Capture 100.00% Electron Capture with delayed Proton Emission ~ 27.00% 21 122 milliseconds Electron Capture 100.00% Electron Capture with delayed Proton Emission 32.60% Electron Capture with delayed Alpha Decay < 0.50%

486

It's Elemental - Isotopes of the Element Chlorine  

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

Sulfur Sulfur Previous Element (Sulfur) The Periodic Table of Elements Next Element (Argon) Argon Isotopes of the Element Chlorine [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 35 75.76% STABLE 37 24.24% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 28 No Data Available Proton Emission (suspected) No Data Available 29 < 20 nanoseconds Proton Emission No Data Available 30 < 30 nanoseconds Proton Emission No Data Available 31 150 milliseconds Electron Capture 100.00% Electron Capture with delayed Proton Emission 0.70% 32 298 milliseconds Electron Capture 100.00%

487

It's Elemental - Isotopes of the Element Potassium  

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

Argon Argon Previous Element (Argon) The Periodic Table of Elements Next Element (Calcium) Calcium Isotopes of the Element Potassium [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 39 93.2581% STABLE 40 0.0117% 1.248×10+9 years 41 6.7302% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 32 No Data Available Proton Emission (suspected) No Data Available 33 < 25 nanoseconds Proton Emission No Data Available 34 < 25 nanoseconds Proton Emission No Data Available 35 178 milliseconds Electron Capture 100.00% Electron Capture with delayed Proton Emission 0.37% 36 342 milliseconds Electron Capture 100.00%

488

It's Elemental - Isotopes of the Element Phosphorus  

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

Silicon Silicon Previous Element (Silicon) The Periodic Table of Elements Next Element (Sulfur) Sulfur Isotopes of the Element Phosphorus [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 31 100% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 24 No Data Available Electron Capture (suspected) No Data Available Proton Emission (suspected) No Data Available 25 < 30 nanoseconds Proton Emission 100.00% 26 43.7 milliseconds Electron Capture 100.00% Electron Capture with delayed Proton Emission No Data Available 27 260 milliseconds Electron Capture 100.00% Electron Capture with

489

It's Elemental - Isotopes of the Element Francium  

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

Radon Radon Previous Element (Radon) The Periodic Table of Elements Next Element (Radium) Radium Isotopes of the Element Francium [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Francium has no naturally occurring isotopes. Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 199 12 milliseconds Alpha Decay > 0.00% Electron Capture No Data Available 200 49 milliseconds Alpha Decay 100.00% 201 62 milliseconds Alpha Decay 100.00% 201m 19 milliseconds Alpha Decay 100.00% 202 0.30 seconds Alpha Decay 100.00% 202m 0.29 seconds Alpha Decay 100.00% 203 0.55 seconds Alpha Decay <= 100.00% 204 1.8 seconds Alpha Decay 92.00%

490

It's Elemental - Isotopes of the Element Oxygen  

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

Nitrogen Nitrogen Previous Element (Nitrogen) The Periodic Table of Elements Next Element (Fluorine) Fluorine Isotopes of the Element Oxygen [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 16 99.757% STABLE 17 0.038% STABLE 18 0.205% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 12 1.139×10-21 seconds Proton Emission No Data Available 13 8.58 milliseconds Electron Capture 100.00% Electron Capture with delayed Proton Emission 100.00% 14 70.620 seconds Electron Capture 100.00% 15 122.24 seconds Electron Capture 100.00% 16 STABLE - - 17 STABLE - - 18 STABLE - - 19 26.88 seconds Beta-minus Decay 100.00%

491

It's Elemental - Isotopes of the Element Gallium  

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

Zinc Zinc Previous Element (Zinc) The Periodic Table of Elements Next Element (Germanium) Germanium Isotopes of the Element Gallium [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 69 60.108% STABLE 71 39.892% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 56 No Data Available Proton Emission (suspected) No Data Available 57 No Data Available Proton Emission (suspected) No Data Available 58 No Data Available Proton Emission (suspected) No Data Available 59 No Data Available Proton Emission (suspected) No Data Available 60 70 milliseconds Electron Capture 98.40%

492

It's Elemental - Isotopes of the Element Sodium  

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

Neon Neon Previous Element (Neon) The Periodic Table of Elements Next Element (Magnesium) Magnesium Isotopes of the Element Sodium [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 23 100% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 18 1.3×10-21 seconds Proton Emission 100.00% 19 < 40 nanoseconds Proton Emission No Data Available 20 447.9 milliseconds Electron Capture with delayed Alpha Decay 20.05% Electron Capture 100.00% 21 22.49 seconds Electron Capture 100.00% 22 2.6027 years Electron Capture 100.00% 23 STABLE - - 24 14.997 hours Beta-minus Decay 100.00%

493

It's Elemental - Isotopes of the Element Neon  

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

Fluorine Fluorine Previous Element (Fluorine) The Periodic Table of Elements Next Element (Sodium) Sodium Isotopes of the Element Neon [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 20 90.48% STABLE 21 0.27% STABLE 22 9.25% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 16 9×10-21 seconds Double Proton Emission 100.00% 17 109.2 milliseconds Electron Capture with delayed Alpha Decay No Data Available Electron Capture 100.00% Electron Capture with delayed Proton Emission 100.00% 18 1.6670 seconds Electron Capture 100.00% 19 17.22 seconds Electron Capture 100.00% 20 STABLE - -

494

It's Elemental - Isotopes of the Element Copper  

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

Nickel Nickel Previous Element (Nickel) The Periodic Table of Elements Next Element (Zinc) Zinc Isotopes of the Element Copper [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 63 69.15% STABLE 65 30.85% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 52 No Data Available Proton Emission No Data Available 53 < 300 nanoseconds Electron Capture No Data Available Proton Emission No Data Available 54 < 75 nanoseconds Proton Emission No Data Available 55 27 milliseconds Electron Capture 100.00% Electron Capture with delayed Proton Emission 15.0% 56 93 milliseconds Electron Capture 100.00%

495

It's Elemental - Isotopes of the Element Boron  

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

Beryllium Beryllium Previous Element (Beryllium) The Periodic Table of Elements Next Element (Carbon) Carbon Isotopes of the Element Boron [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 10 19.9% STABLE 11 80.1% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 6 No Data Available Double Proton Emission (suspected) No Data Available 7 3.255×10-22 seconds Proton Emission No Data Available Alpha Decay No Data Available 8 770 milliseconds Electron Capture 100.00% Electron Capture with delayed Alpha Decay 100.00% 9 8.439×10-19 seconds Proton Emission 100.00% Double Alpha Decay 100.00%

496

It's Elemental - Isotopes of the Element Tungsten  

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

Tantalum Tantalum Previous Element (Tantalum) The Periodic Table of Elements Next Element (Rhenium) Rhenium Isotopes of the Element Tungsten [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 180 0.12% >= 6.6×10+17 years 182 26.50% STABLE 183 14.31% > 1.3×10+19 years 184 30.64% STABLE 186 28.43% > 2.3×10+19 years Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 157 275 milliseconds Electron Capture No Data Available 158 1.25 milliseconds Alpha Decay 100.00% 158m 0.143 milliseconds Isomeric Transition No Data Available Alpha Decay No Data Available 159 7.3 milliseconds Alpha Decay ~ 99.90%

497

It's Elemental - Isotopes of the Element Radon  

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

Astatine Astatine Previous Element (Astatine) The Periodic Table of Elements Next Element (Francium) Francium Isotopes of the Element Radon [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Radon has no naturally occurring isotopes. Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 193 1.15 milliseconds Alpha Decay 100.00% 194 0.78 milliseconds Alpha Decay 100.00% 195 6 milliseconds Alpha Decay 100.00% 195m 5 milliseconds Alpha Decay 100.00% 196 4.4 milliseconds Alpha Decay 99.90% Electron Capture ~ 0.10% 197 53 milliseconds Alpha Decay 100.00% 197m 25 milliseconds Alpha Decay 100.00% 198 65 milliseconds Alpha Decay No Data Available

498

It's Elemental - Isotopes of the Element Carbon  

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

Boron Boron Previous Element (Boron) The Periodic Table of Elements Next Element (Nitrogen) Nitrogen Isotopes of the Element Carbon [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 12 98.93% STABLE 13 1.07% STABLE Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 8 1.981×10-21 seconds Proton Emission 100.00% Alpha Decay No Data Available 9 126.5 milliseconds Electron Capture 100.00% Electron Capture with delayed Proton Emission 61.60% Electron Capture with delayed Alpha Decay 38.40% 10 19.308 seconds Electron Capture 100.00% 11 20.334 minutes Electron Capture 100.00% 12 STABLE - -

499

It's Elemental - Isotopes of the Element Rhenium  

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

Tungsten Tungsten Previous Element (Tungsten) The Periodic Table of Elements Next Element (Osmium) Osmium Isotopes of the Element Rhenium [Click for Main Data] Most of the isotope data on this site has been obtained from the National Nuclear Data Center. Please visit their site for more information. Naturally Occurring Isotopes Mass Number Natural Abundance Half-life 185 37.40% STABLE 187 62.60% 4.33×10+10 years Known Isotopes Mass Number Half-life Decay Mode Branching Percentage 159 No Data Available No Data Available No Data Available 160 0.82 milliseconds Proton Emission 91.00% Alpha Decay 9.00% 161 0.44 milliseconds Proton Emission 100.00% Alpha Decay <= 1.40% 161m 14.7 milliseconds Alpha Decay 93.00% Proton Emission 7.00% 162 107 milliseconds Alpha Decay 94.00% Electron Capture 6.00%

500

Sign elements in symmetric groups Jrn B. Olsson  

E-Print Network [OSTI]

;Introduction Work in progress Question by G. Navarro about characters in symmetric groups, related to a paper characters · The Isaacs-Navarro question · Sign elements/classes in finite groups and their relation groups · Answering the Isaacs-Navarro question · A general result about sign classes in symmetric groups

Takahashi, Ryo

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