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Note: This page contains sample records for the topic "logit fuel-sharing equations" from the National Library of EnergyBeta (NLEBeta).
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1

Analysis of fuel shares in the industrial sector  

SciTech Connect

These studies describe how fuel shares have changed over time; determine what factors are important in promoting fuel share changes; and project fuel shares to the year 1995 in the industrial sector. A general characterization of changes in fuel shares of four fuel types - coal, natural gas, oil and electricity - for the industrial sector is as follows. Coal as a major fuel source declined rapidly from 1958 to the early 1970s, with oil and natural gas substituting for coal. Coal's share of total fuels stabilized after the oil price shock of 1972-1973, and increased after the 1979 price shock. In the period since 1973, most industries and the industrial sector as a whole appear to freely substitute natural gas for oil, and vice versa. Throughout the period 1958-1981, the share of electricity as a fuel increased. These observations are derived from analyzing the fuel share patterns of more than 20 industries over the 24-year period 1958 to 1981.

Roop, J.M.; Belzer, D.B.

1986-06-01T23:59:59.000Z

2

Residential Self Selection and Rail Commuting: A Nested Logit Analysis  

E-Print Network (OSTI)

An error was discovered in the original Table 1 of this study. Notably, the Inclusive terms for the upper-nest model were incorrectly calculated thus the theta terms were in error. This revised working paper corrects this error. Also, the corrected upper nest model has a slightly different specification than originally shown in Table 1 in order to satisfy the condition that the theta values lie between 0 and 1. Some additional text is added to the original working paper regarding the new upper level model, however none of the substantive findings or conclusions of the research change as a result. The additional variables added to the upper nest model reveal that low automobile ownership levels tended to be associated with transit-oriented living. We acknowledge that automobile ownership likely both influences and is influenced by transit-oriented living, thus the coefficient on the automobile ownership variables could be subject to endogeneity bias. The revised equation also shows that controlling for other variables in the equation, having individuals 55 years of age and above in a household reduced the likelihood of living near transit. It is also noted that the estimated coefficients in the lower nest binomial logit models for predicting rail commuting (shown in the right-hand

Robert Cervero; Michael Duncan

2002-01-01T23:59:59.000Z

3

Residential Self Selection and Rail Commuting: A Nested Logit Analysis  

E-Print Network (OSTI)

Study of Housing Built Near Rail Transit Stations: NorthernLogit Model Results for Upper Nest (Rail Location Choice)and Lower Nest (Rail Commute Choice). Note: Revised from

Cervero, Robert; Duncan, Michael

2008-01-01T23:59:59.000Z

4

Residential Self Selection and Rail Commuting: A Nested Logit Analysis  

E-Print Network (OSTI)

Study of Housing Built Near Rail Transit Stations: NorthernLogit Model Results for Upper Nest (Rail Location Choice)and Lower Nest (Rail Commute Choice). Note: Revised from

Cervero, Robert; Duncan, Michael

2002-01-01T23:59:59.000Z

5

A Finite Mixture Logit Model to Segment and Predict Electronic Payments System Adoption  

Science Conference Proceedings (OSTI)

Despite much hype about electronic payments systems (EPSs), a 2004 survey establishes that close to 80% of between-business payments are still made using paper-based formats. We present a finite mixture logit model to predict likelihood of EPS adoption ... Keywords: clustering analysis, electronic payments systems, finite mixture model, hierarchical logit regression, logistic regression, market segmentation

Ravi Bapna; Paulo Goes; Kwok Kee Wei; Zhongju Zhang

2011-03-01T23:59:59.000Z

6

Estimating long-term world coal production with logit and probit transforms David Rutledge  

E-Print Network (OSTI)

Estimating long-term world coal production with logit and probit transforms David Rutledge form 27 October 2010 Accepted 27 October 2010 Available online 4 November 2010 Keywords: Coal reserves Coal resources Coal production estimates IPCC Logistic model Cumulative normal model An estimate

Weinreb, Sander

7

Penetration equations  

Science Conference Proceedings (OSTI)

In 1967, Sandia National Laboratories published empirical equations to predict penetration into natural earth materials and concrete. Since that time there have been several small changes to the basic equations, and several more additions to the overall technique for predicting penetration into soil, rock, concrete, ice, and frozen soil. The most recent update to the equations was published in 1988, and since that time there have been changes in the equations to better match the expanding data base, especially in concrete penetration. This is a standalone report documenting the latest version of the Young/Sandia penetration equations and related analytical techniques to predict penetration into natural earth materials and concrete. 11 refs., 6 tabs.

Young, C.W. [Applied Research Associates, Inc., Albuquerque, NM (United States)

1997-10-01T23:59:59.000Z

8

Equational descriptions of languages ?  

E-Print Network (OSTI)

This paper is a survey on the equational descriptions of languages. The first part is devoted to Birkhoff’s and Reiterman’s theorems on equational descriptions of varieties. Eilenberg’s variety theorem and its successive generalizations form the second part. The more recent results on equational descriptions of lattices of languages are presented in the third part of the paper. Equations have been used for a long time in mathematics to provide a concise description of various mathematical objects. This article roughly follows a historical approach to present such equational descriptions for formal languages, ranging over a period of 45 years: from Schützenberger’s characterization of star-free languages [36] to the following recent result of [18]: Every lattice of languages admits an equational description. This evolution was made possible by a gradual abstraction of the notion of equation. The story really starts in 1935 with Birkhoff’s theorem on equational

Jean-éric Pin

2012-01-01T23:59:59.000Z

9

Lanczos's equation to replace Dirac's equation ?  

E-Print Network (OSTI)

Lanczos's quaternionic interpretation of Dirac's equation provides a unified description for all elementary particles of spin 0, 1/2, 1, and 3/2. The Lagrangian formulation given by Einstein and Mayer in 1933 predicts two main classes of solutions. (1) Point like partons which come in two families, quarks and leptons. The correct fractional or integral electric and baryonic charges, and zero mass for the neutrino and the u-quark, are set by eigenvalue equations. The electro-weak interaction of the partons is the same as with the Standard model, with the same two free parameters: e and sin^2 theta. There is no need for a Higgs symmetry breaking mechanism. (2) Extended hadrons for which there is no simple eigenvalue equation for the mass. The strong interaction is essentially non-local. The pion mass and pion-nucleon coupling constant determine to first order the nucleon size, mass and anomalous magnetic moment.

Andre Gsponer; Jean-Pierre Hurni

2001-12-23T23:59:59.000Z

10

TUTORIALS: Copolymer Equation  

Science Conference Proceedings (OSTI)

Aug 17, 2007 ... This JAVA applet plots the copolymer equation and lets you explore the effect of varying the parameters. Theory and references are provided.

11

Partial Differential Equations  

Science Conference Proceedings (OSTI)

Table 3   Linear partial differential equations...fluids, electromagnetic) Damped waves, transmission lines Elliptic (c) Static case 2 Φ = f ( r ) 4th order (b) Elastic vibrations 4th order (c) Static

12

SIMULTANEOUS DIFFERENTIAL EQUATION COMPUTER  

DOE Patents (OSTI)

A description is given for an electronic simulator for a system of simultaneous differential equations, including nonlinear equations. As a specific example, a homogeneous nuclear reactor system including a reactor fluid, heat exchanger, and a steam boiler may be simulated, with the nonlinearity resulting from a consideration of temperature effects taken into account. The simulator includes three operational amplifiers, a multiplier, appropriate potential sources, and interconnecting R-C networks.

Collier, D.M.; Meeks, L.A.; Palmer, J.P.

1960-05-10T23:59:59.000Z

13

On Free Stochastic Differential Equations  

E-Print Network (OSTI)

The paper derives an equation for the Cauchy transform of the solution of a free stochastic differential equation (SDE). This new equation is used to solve several particular examples of free SDEs.

Kargin, Vladsislav

2011-01-01T23:59:59.000Z

14

Information Equation of State  

E-Print Network (OSTI)

Landauer's principle is applied to information in the universe. Once stars began forming, the increasing proportion of matter at high stellar temperatures compensated for the expanding universe to provide a near constant information energy density. The information equation of state was close to the dark energy value, w = -1, for a wide range of redshifts, 10> z >0.8, over one half of cosmic time. A reasonable universe information bit content of only 10^87 bits is sufficient for information energy to account for all dark energy. A time varying equation of state with a direct link between dark energy and matter, and linked to star formation in particular, is clearly relevant to the cosmic coincidence problem.In answering the "Why now?" question we wonder "What next?" as we expect the information equation of state to tend towards w = 0 in the future.

Paul Gough

2007-09-05T23:59:59.000Z

15

Loop Equation in Turbulence  

E-Print Network (OSTI)

The incompressible fluid dynamics is reformulated as dynamics of closed loops $C$ in coordinate space. This formulation allows to derive explicit functional equation for the generating functional $\\Psi[C]$ in inertial range of spatial scales, which allows the scaling solutions. The requirement of finite energy dissipation rate leads then to the Kolmogorov index. We find an exact steady solution of the loop equation in inertial range of the loop sizes. The generating functional decreases as $\\EXP{-A^{\\tt}}$ where $A=\\oint_C r \\wedge dr$ is the area inside the loop. The pdf for the velocity circulation $\\Gamma$ is Lorentzian, with the width $\\bar{\\Gamma} \\propto A^{\\tt} $.

Alexander A. Migdal

1993-03-23T23:59:59.000Z

16

A Master Equation Approach to the `3 + 1' Dirac Equation  

E-Print Network (OSTI)

A derivation of the Dirac equation in `3+1' dimensions is presented based on a master equation approach originally developed for the `1+1' problem by McKeon and Ord. The method of derivation presented here suggests a mechanism by which the work of Knuth and Bahrenyi on causal sets may be extended to a derivation of the Dirac equation in the context of an inference problem.

Keith A. Earle

2011-02-06T23:59:59.000Z

17

Spinor wave equation of photon  

E-Print Network (OSTI)

In this paper, we give the spinor wave equations of free and unfree photon, which are the differential equation of space-time one order. For the free photon, the spinor wave equations are covariant, and the spinors $\\psi$ are corresponding to the the reducibility representations $D^{10}+D^{01}$ and $D^{10}+D^{01}+D^{1/2 1/2}$ of the proper Lorentz group.

Xiang-Yao Wu; Bo-Jun Zhang; Xiao-Jing Liu; Si-Qi Zhang; Jing Wang; Hong Li; Xi-Hui Fan; Jing-Wu Li

2012-12-14T23:59:59.000Z

18

Nonlinear graphene plasmonics: amplitude equation  

E-Print Network (OSTI)

Using perturbation expansion of Maxwell equations, the amplitude equation is derived for nonlinear TM and TE surface plasmon waves supported by graphene. The equation describes interplay between in-plane beam diffraction and nonlinerity due to light intensity induced corrections to graphene conductivity and susceptibility of dielectrics. For strongly localized TM plasmons, graphene is found to bring the superior contribution to the overall nonlinearity. In contrast, nonlinear response of the substrate and cladding dielectrics can become dominant for weakly localized TE plasmons.

Gorbach, A V

2013-01-01T23:59:59.000Z

19

Rational Approximation for a Quasilinear Parabolic Equation  

E-Print Network (OSTI)

Approximation theorems, analogous to known results for linear elliptic equations, are obtained for solutions of the heat equation. Via the Cole-Hopf transformation, this gives rise to approximation theorems for a nonlinear parabolic equation, Burgers' equation.

P. M. Gauthier; N. Tarkhanov

2007-09-22T23:59:59.000Z

20

Iterative solution of differential equations  

E-Print Network (OSTI)

We discuss alternative iteration methods for differential equations. We provide a convergence proof for exactly solvable examples and show more convenient formulas for nontrivial problems.

Paolo Amore; Hakan Ciftci; Francisco M. Fernandez

2006-09-29T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

Conservation laws of semidiscrete canonical Hamiltonian equations  

E-Print Network (OSTI)

There are many evolution partial differential equations which can be cast into Hamiltonian form. Conservation laws of these equations are related to one-parameter Hamiltonian symmetries admitted by the PDEs. The same result holds for semidiscrete Hamiltonian equations. In this paper we consider semidiscrete canonical Hamiltonian equations. Using symmetries, we find conservation laws for the semidiscretized nonlinear wave equation and Schrodinger equation.

Roman Kozlov

2004-02-25T23:59:59.000Z

22

A search on Dirac equation  

E-Print Network (OSTI)

The solutions, in terms of orthogonal polynomials, of Dirac equation with analytically solvable potentials are investigated within a novel formalism by transforming the relativistic equation into a Schrodinger like one. Earlier results are discussed in a unified framework and certain solutions of a large class of potentials are given.

M Kocak; B Gonul

2007-02-15T23:59:59.000Z

23

Entropic corrections to Einstein equations  

SciTech Connect

Considering the general quantum corrections to the area law of black hole entropy and adopting the viewpoint that gravity interprets as an entropic force, we derive the modified forms of Modified Newtonian dynamics (MOND) theory of gravitation and Einstein field equations. As two special cases we study the logarithmic and power-law corrections to entropy and find the explicit form of the obtained modified equations.

Hendi, S. H. [Physics Department, College of Sciences, Yasouj University, Yasouj 75914 (Iran, Islamic Republic of); Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of); Sheykhi, A. [Research Institute for Astronomy and Astrophysics of Maragha (RIAAM), Maragha (Iran, Islamic Republic of); Department of Physics, Shahid Bahonar University, P.O. Box 76175-132, Kerman (Iran, Islamic Republic of)

2011-04-15T23:59:59.000Z

24

Renewal equations for option pricing  

E-Print Network (OSTI)

In this paper we will develop an original approach, based in the use of renewal equations, for obtaining pricing expressions for financial instruments whose underlying asset can be solely described through a simple continuous-time random walk (CTRW). This enhances the potential use of CTRW techniques in finance. We solve these equations for different contract specifications in a particular but exemplifying case. We recover the celebrated results for the Wiener process under certain limits.

Montero, Miquel

2007-01-01T23:59:59.000Z

25

String Field Equations from Generalized Sigma Model  

E-Print Network (OSTI)

I I . i LBNL-39854 String Field Equations fromU C B - P T H - 9 7 / 0 3 String F i e l d Equations fromnew approach for deriving the string field equations from a

Bardakci, K.

2010-01-01T23:59:59.000Z

26

Unified Fractional Kinetic Equation and a Fractional Diffusion Equation  

E-Print Network (OSTI)

In earlier papers Saxena et al. (2002, 2003) derived the solutions of a number of fractional kinetic equations in terms of generalized Mittag-Leffler functions which extended the work of Haubold and Mathai (2000). The object of the present paper is to investigate the solution of a unified form of fractional kinetic equation in which the free term contains any integrable function f(t), which provides the unification and extension of the results given earlier recently by Saxena et al. (2002, 2003). The solution has been developed in terms of the Wright function in a closed form by the method of Laplace transform. Further we derive a closed-form solution of a fractional diffusion equation. The asymptotic expansion of the derived solution with respect to the space variable is also discussed. The results obtained are in a form suitable for numerical computation.

R. K. Saxena; A. M. Mathai; H. J. Haubold

2004-06-22T23:59:59.000Z

27

Parallel Objects and Field Equations  

E-Print Network (OSTI)

This paper considers a generalization of the existing concept of parallel (with respect to a given connection) geometric objects and its possible usage as a suggesting rule in searching for adequate field equations in theoretical physics. The generalization tries to represent mathematically the two-sided nature of the physical objects, the {\\it change} and the {\\it conservation}. The physical objects are presented mathematically by sections $\\Psi$ of vector bundles, the admissible changes $D\\Psi$ are described as a rsult of the action of appropriate differential operators $D$ on these sections, and the conservation propertieis are accounted for by the requirement that suitable projections of $D\\Psi$ on $\\Psi$ and on other appropriate sections must be zero. It is shown that the most important equations of theoretical physics obey this rule. Extended forms of Maxwell and Yang-Mills equations are also considered.

Stoil Donev; Maria Tashkova

2002-05-30T23:59:59.000Z

28

Monte Carlo Methods and Partial Differential Equations ...  

Science Conference Proceedings (OSTI)

... Up, Monte Carlo Methods and Partial Differential Equations: Algorithms and Implications for High-Performance Computing. ...

2013-08-16T23:59:59.000Z

29

Residential Self Selection and Rail Commuting: A Nested Logit Analysis  

E-Print Network (OSTI)

Improvement Program (STIP) funds for each bedroom builtmore than $2.2 million of STIP funds were transferred to

Cervero, Robert; Duncan, Michael

2008-01-01T23:59:59.000Z

30

Residential Self Selection and Rail Commuting: A Nested Logit Analysis  

E-Print Network (OSTI)

Improvement Program (STIP) funds for each bedroom builtmore than $2.2 million of STIP funds were transferred to

Cervero, Robert; Duncan, Michael

2002-01-01T23:59:59.000Z

31

Residential Self Selection and Rail Commuting: A Nested Logit Analysis  

E-Print Network (OSTI)

housing near rail stations, research on self-selection canrail or commuter rail station. Research can also help informfor rail transit to reach their workplaces. This research

Cervero, Robert; Duncan, Michael

2008-01-01T23:59:59.000Z

32

Residential Self Selection and Rail Commuting: A Nested Logit Analysis  

E-Print Network (OSTI)

housing near rail stations, research on self-selection canrail or commuter rail station. Research can also help informfor rail transit to reach their workplaces. This research

Cervero, Robert; Duncan, Michael

2002-01-01T23:59:59.000Z

33

Residential Self Selection and Rail Commuting: A Nested Logit Analysis  

E-Print Network (OSTI)

Holtzclaw, J. 1994. Using Residential Patterns and TransitOwnership and Use: How Much Does Residential Density Matter?to transit when making residential choices. Table 1. Nested

Cervero, Robert; Duncan, Michael

2008-01-01T23:59:59.000Z

34

Fractional reaction-diffusion equations  

E-Print Network (OSTI)

In a series of papers, Saxena, Mathai, and Haubold (2002, 2004a, 2004b) derived solutions of a number of fractional kinetic equations in terms of generalized Mittag-Leffler functions which provide the extension of the work of Haubold and Mathai (1995, 2000). The subject of the present paper is to investigate the solution of a fractional reaction-diffusion equation. The results derived are of general nature and include the results reported earlier by many authors, notably by Jespersen, Metzler, and Fogedby (1999) for anomalous diffusion and del-Castillo-Negrete, Carreras, and Lynch (2003) for reaction-diffusion systems with L\\'evy flights. The solution has been developed in terms of the H-function in a compact form with the help of Laplace and Fourier transforms. Most of the results obtained are in a form suitable for numerical computation.

R. K. Saxena; A. M. Mathai; H. J. Haubold

2006-04-21T23:59:59.000Z

35

Green Functions of Relativistic Field Equations  

E-Print Network (OSTI)

In this paper, we restudy the Green function expressions of field equations. We derive the explicit form of the Green functions for the Klein-Gordon equation and Dirac equation, and then estimate the decay rate of the solution to the linear equations. The main motivation of this paper is to show that: (1). The formal solutions of field equations expressed by Green function can be elevated as a postulate for unified field theory. (2). The inescapable decay of the solution of linear equations implies that the whole theory of the matter world should include nonlinear interaction.

Ying-Qiu Gu

2006-12-20T23:59:59.000Z

36

Parabolic equations without a minimum principle  

E-Print Network (OSTI)

In this thesis, we consider several parabolic equations for which the minimum principle fails. We first consider a two-point boundary value problem for a one dimensional diffusion equation. We show the uniqueness and ...

Pang, Huadong

2007-01-01T23:59:59.000Z

37

Moisture Tendency Equations in a Tropical Atmosphere  

Science Conference Proceedings (OSTI)

Direct diagnostic evaluation of the moisture tendency in the moisture equation is very difficult in practice because two poorly measured terms, moisture convergence and precipitation, dominate the equation. Using the near constancy in space and ...

C. López Carrillo; D. J. Raymond

2005-05-01T23:59:59.000Z

38

Vorticity Equation Terms for Extratropical Cyclones  

Science Conference Proceedings (OSTI)

All terms of the frictionless, nonlinear, vorticity equation are examined. Traditional scale analysis provides one of several justifications for using the quasigeostrophic (QG) system of equations to model extratropical cyclones. Analysts of ...

Richard Grotjahn

1996-12-01T23:59:59.000Z

39

Feynman Equation in Hamiltonian Quantum Field Theory  

E-Print Network (OSTI)

Functional Schr\\"{o}dinger equations for interacting fields are solved via rigorous non-perturbative Feynman type integrals.

Alexander Dynin

2000-05-26T23:59:59.000Z

40

Linearized gyro-kinetic equation  

SciTech Connect

An ordering of the linearized Fokker-Planck equation is performed in which gyroradius corrections are retained to lowest order and the radial dependence appropriate for sheared magnetic fields is treated without resorting to a WKB technique. This description is shown to be necessary to obtain the proper radial dependence when the product of the poloidal wavenumber and the gyroradius is large (k rho much greater than 1). A like particle collision operator valid for arbitrary k rho also has been derived. In addition, neoclassical, drift, finite $beta$ (plasma pressure/magnetic pressure), and unperturbed toroidal electric field modifications are treated. (auth)

Catto, P.J.; Tsang, K.T.

1976-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

REGULARITY FOR A DOUBLY NONLINEAR PARABOLIC EQUATION  

E-Print Network (OSTI)

REGULARITY FOR A DOUBLY NONLINEAR PARABOLIC EQUATION JUHA KINNUNEN Abstract. This survey focuses on regularity results for certain degenerate doubly nonlinear parabolic equations in the case when the Lebesgue This note focuses on the regularity of nonnegative weak solutions to the doubly nonlinear parabolic equation

Kinnunen, Juha

42

Coupled Parabolic Equations for Wave Propagation  

E-Print Network (OSTI)

Coupled Parabolic Equations for Wave Propagation Kai Huang, Knut Solna and Hongkai Zhao #3; April 30, 2004 Abstract We develop an algorithm using two coupled parabolic equations for numerical simulation of wave propagation over long distances. The coupled parabolic equations are derived from a two

Zhao, Hongkai

43

Tensor transformation technique for the transport equation  

SciTech Connect

A step-wise tensor transformation technique is presented for the transformation of the single energy group transport equation to an arbitrary spatial coordinate system. Both gradient and divergence forms of the equation are given and the same method is applied to the derivation of the diffusion approximation. It is demonstrated that using an orthogonal representation of the propagation vector will simplify the divergence form of the equation. The application of this technique is in the representation of the transport equation in coordinate systems other than the usual rectangular, cylindrical and spherical ones. Its use is demonstrated by transforming the transport equation to a toroidal coordinate system consisting of nested circular toroids. (auth)

Gralnick, S.L.

1975-10-01T23:59:59.000Z

44

Solving metamaterial Maxwell's equations via a vector wave integro-differential equation  

Science Conference Proceedings (OSTI)

In this paper, we discuss the time-domain metamaterial Maxwell's equations. One major contribution of this paper is that after some effort we find that the metamaterial Maxwell's equations can be beautifully reduced to a vector wave integro-differential ... Keywords: Finite element method, Maxwell's equations, Metamaterials, Vector wave equation

Yunqing Huang; Jichun Li; Wei Yang

2012-06-01T23:59:59.000Z

45

Equator Appliance: ENERGY STAR Referral (EZ 3720) | Department...  

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

Equator Appliance: ENERGY STAR Referral (EZ 3720) Equator Appliance: ENERGY STAR Referral (EZ 3720) October 5, 2010 DOE referred Equator Appliance clothes washer EZ 3720 to EPA,...

46

Equator Appliance: ENERGY STAR Referral (EZ 3720 CEE) | Department...  

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

Equator Appliance: ENERGY STAR Referral (EZ 3720 CEE) Equator Appliance: ENERGY STAR Referral (EZ 3720 CEE) October 5, 2010 DOE referred the matter of Equator clothes washer model...

47

Transport equations in axisymmetric toroidal coordinates  

SciTech Connect

A derivation is presented of the conservation law form of the single energy group transport equation in an axisymmetric toroidal coordinate system formed by rotating a nest of smooth, simply closed, plane curves of arbitrary parametric description about an axis which does not intersect the nest. This general equation may be used for generating equations specific to particular cross section geometries, or as the basis of a finite difference equation for the general case. The effect of both the toroidal and poloidal curvatures of the system are investigated, and criteria for the validity of cylindrical and planar approximations are established. The diffusion equation for this geometry is derived, and it is shown to be formally homologous to the ''r-theta'' cylindrical diffusion equation if the coordinate system is orthogonal and if the azimuthal coordinate, phi, is ignorable. (auth)

Gralnick, S.L.

1975-12-01T23:59:59.000Z

48

From Maxwell Stresses to Nonlinear Field Equations  

E-Print Network (OSTI)

This paper aims to show that making use of Newton's view on equations of motion of a physical system and of the Maxwell stress tensor we come to a natural nonlinearization of Maxwell equations in vacuum making use only of nonrelativistic terms. The new equations include all Maxwell solutions plus new ones, among which one may find time-stable and spatially finite ones with photon-like properties and behavior.

Donev, S; Donev, Stoil; Tashkova, Maria

2006-01-01T23:59:59.000Z

49

From Maxwell Stresses to Nonlinear Field Equations  

E-Print Network (OSTI)

This paper aims to show that making use of Newton's view on equations of motion of a physical system and of the Maxwell stress tensor we come to a natural nonlinearization of Maxwell equations in vacuum making use only of nonrelativistic terms. The new equations include all Maxwell solutions plus new ones, among which one may find time-stable and spatially finite ones with photon-like properties and behavior.

Stoil Donev; Maria Tashkova

2006-04-04T23:59:59.000Z

50

A counterexample against the Vlasov equation  

E-Print Network (OSTI)

A simple counterexample against the Vlasov equation is put forward, in which a magnetized plasma is perturbed by an electromagnetic standing wave.

C. Y. Chen

2009-04-19T23:59:59.000Z

51

Coordinate-Independent Computations on Differential Equations  

E-Print Network (OSTI)

This project investigates the computational representation of differentiable manifolds, with the primary goal of solving partial differential equations using multiple coordinate systems on general n- dimensional spaces. ...

Lin, Kevin K.

1998-03-01T23:59:59.000Z

52

Supplementary Backward Equations for the Industrial ...  

Science Conference Proceedings (OSTI)

... of Water and Steam for Fast Calculations of Heat Cycles, Boilers, and Steam ... boundary equations is sufficient for most heat-cycle, boiler, and steam ...

2006-07-20T23:59:59.000Z

53

Stochastic Master Equations in Thermal Environment  

E-Print Network (OSTI)

We derive the stochastic master equations which describe the evolution of open quantum systems in contact with a heat bath and undergoing indirect measurements. These equations are obtained as a limit of a quantum repeated measurement model where we consider a small system in contact with an infinite chain at positive temperature. At zero temperature it is well-known that one obtains stochastic differential equations of jump-diffusion type. At strictly positive temperature, we show that only pure diffusion type equations are relevant.

S Attal; C Pellegrini

2010-04-20T23:59:59.000Z

54

Viscosity and Thermal Conductivity Equations for Nitrogen ...  

Science Conference Proceedings (OSTI)

... that both could be used as reference equations for ... the National Institute of Standards and Technology (NIST). ... of state for air as a pseudo-pure fluid. ...

2004-04-05T23:59:59.000Z

55

Solving Systems of Algebraic Equations, - CECM  

E-Print Network (OSTI)

current complexity of expressions for many types of equations is computed as .... redoing these calculations, we make use of Maple's remember facility. Briefly ...

56

String Field Equations from Generalized Sigma Model  

E-Print Network (OSTI)

beta function computed in the one loop approximation, using the background fieldfield equations are then derived by imposing quantum scale invariance, which amounts to demanding that the beta

Bardakci, K.

2010-01-01T23:59:59.000Z

57

Proper Time Flow Equation for Gravity  

E-Print Network (OSTI)

We analyze a proper time renormalization group equation for Quantum Einstein Gravity in the Einstein-Hilbert truncation and compare its predictions to those of the conceptually different exact renormalization group equation of the effective average action. We employ a smooth infrared regulator of a special type which is known to give rise to extremely precise critical exponents in scalar theories. We find perfect consistency between the proper time and the average action renormalization group equations. In particular the proper time equation, too, predicts the existence of a non-Gaussian fixed point as it is necessary for the conjectured nonperturbative renormalizability of Quantum Einstein Gravity.

Bonanno, A

2005-01-01T23:59:59.000Z

58

Parabolic equations without a minimum principle.  

E-Print Network (OSTI)

??In this thesis, we consider several parabolic equations for which the minimum principle fails. We first consider a two-point boundary value problem for a one… (more)

Pang, Huadong

2007-01-01T23:59:59.000Z

59

Schroedinger Equation of the Schwarzschild Black Hole  

E-Print Network (OSTI)

We describe the gravitational degrees of freedom of the Schwarzschild black hole by one free variable. We introduce an equation which we suggest to be the Schroedinger equation of the Schwarzschild black hole corresponding to this model. We solve the Schroedinger equation explicitly and obtain the mass spectrum of the black hole as such as it can be observed by an observer very far away and at rest relative to the black hole. Our equation implies that there is no singularity inside the Schwarzschild black hole, and that the black hole has a certain ground state in which its mass is non-zero.

Jarmo Makela

1996-02-05T23:59:59.000Z

60

SOURCE TERMS IN THE TRANSIENT SEEPAGE EQUATION  

E-Print Network (OSTI)

Equation; Pore Pressure Generation; Sources; Source Terms)In this paper, sources involving the generation of mass areincludes source terms for both fluid mass generation and

Narasimhan, T.N.

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

New Type of Soliton Equation Described Some Statistical Distributions and Nonlinear Equations Unified Quantum Statistics  

E-Print Network (OSTI)

We proposed a new type of soliton equation, whose solutions may describe some statistical distributions, for example, Cauchy distribution, normal distribution and student distribution, etc. The equation possesses two characters. Further, from an extension of this type of equation we may obtain the exponential distribution, and the Fermi-Dirac distribution in quantum statistics. Moreover, by using the method of the soliton-solution, the nonlinear Klein-Gordon equation and nonlinear Dirac equations may derive Bose-Einstein and Fermi-Dirac distributions, respectively, and both distributions may be unified by the nonlinear equation.

Yi-Fang Chang

2009-02-02T23:59:59.000Z

62

A Fast Spectral Subtractional Solver for Elliptic Equations  

Science Conference Proceedings (OSTI)

The paper presents a fast subtractional spectral algorithm for the solution of the Poisson equation and the Helmholtz equation which does not require an extension of the original domain. It takes O(N2 log N) operations, ... Keywords: equations in complex geometries, fast spectral direct solver, preconditioned iterative algorithm for elliptic equations, the Poisson equation, the modified Helmholtz equation

Elena Braverman; Boris Epstein; Moshe Israeli; Amir Averbuch

2004-08-01T23:59:59.000Z

63

Global Optimization with Nonlinear Ordinary Differential Equations  

Science Conference Proceedings (OSTI)

This paper examines global optimization of an integral objective function subject to nonlinear ordinary differential equations. Theory is developed for deriving a convex relaxation for an integral by utilizing the composition result defined by McCormick ... Keywords: Convex relaxations, dynamic optimization, nonquasimonotone differential equations

Adam B. Singer; Paul I. Barton

2006-02-01T23:59:59.000Z

64

Degenerate Parabolic Stochastic Partial Differential Equations  

E-Print Network (OSTI)

Degenerate Parabolic Stochastic Partial Differential Equations Martina Hofmanov´a Abstract. We study the Cauchy problem for a scalar semilinear degenerate parabolic partial differential equation the notion of kinetic solution which is well suited for degenerate parabolic problems and supplies a good

Paris-Sud XI, Université de

65

Waves along the Equator in the Atlantic  

Science Conference Proceedings (OSTI)

Spectra of two hundred days of data from five inverted echo sounders deployed along the equator in 1983–84 and a thousand days of 30 crossings of the equator by the TOPEX/POSEIDON altimeter in 1993–95 are both found to have enhanced variance of ...

Eli Joel Katz

1997-12-01T23:59:59.000Z

66

Derivation of Maxwell-like equations from the quaternionic Dirac's equation  

E-Print Network (OSTI)

Expanding the ordinary Dirac's equation, $\\frac{1}{c}\\frac{\\partial\\psi}{\\partial t}+\\vec{\\alpha}\\cdot\\vec{\

A. I. Arbab

2013-01-17T23:59:59.000Z

67

Solutions of the Fractional Reaction Equation and the Fractional Diffusion Equation  

E-Print Network (OSTI)

In view of the role of reaction equations in physical problems, the authors derive the explicit solution of a fractional reaction equation of general character, that unifies and extends earlier results. Further, an alternative shorter method based on a result developed by the authors is given to derive the solution of a fractional diffusion equation. Fox functions and Mittag-Leffler functions are used for closed-form representations of the solutions of the respective differential equations.

R. K. Saxena; A. M. Mathai; H. J. Haubold

2010-01-13T23:59:59.000Z

68

Splitting schemes for hyperbolic heat conduction equation  

E-Print Network (OSTI)

Rapid processes of heat transfer are not described by the standard heat conduction equation. To take into account a finite velocity of heat transfer, we use the hyperbolic model of heat conduction, which is connected with the relaxation of heat fluxes. In this case, the mathematical model is based on a hyperbolic equation of second order or a system of equations for the temperature and heat fluxes. In this paper we construct for the hyperbolic heat conduction equation the additive schemes of splitting with respect to directions. Unconditional stability of locally one-dimensional splitting schemes is established. New splitting schemes are proposed and studied for a system of equations written in terms of the temperature and heat fluxes.

Vabishchevich, Petr N

2010-01-01T23:59:59.000Z

69

A Cartesian grid embedded boundary method for the heat equation and Poissons equation in three dimensions  

E-Print Network (OSTI)

A Cartesian grid embedded boundary method for the heat equation and Poisson�s equation in three­85] and extends work of McCorquodale, Colella and Johansen [A Cartesian grid embedded boundary method for the heat and time for the heat equation. Cartesian grid methods for elliptic PDE have a long history beginning with the no

70

From chemical Langevin equations to Fokker-Planck equation: application of Hodge decomposition and Klein-Kramers equation  

E-Print Network (OSTI)

The stochastic systems without detailed balance are common in various chemical reaction systems, such as metabolic network systems. In studies of these systems, the concept of potential landscape is useful. However, what are the sufficient and necessary conditions of the existence of the potential function is still an open problem. Use Hodge decomposition theorem in differential form theory, we focus on the general chemical Langevin equations, which reflect complex chemical reaction systems. We analysis the conditions for the existence of potential landscape of the systems. By mapping the stochastic differential equations to a Hamiltonian mechanical system, we obtain the Fokker-Planck equation of the chemical reaction systems. The obtained Fokker-Planck equation can be used in further studies of other steady properties of complex chemical reaction systems, such as their steady state entropies.

Weihua Mu; Xiaoqing Li; Zhongcan Ou-Yang

2010-09-19T23:59:59.000Z

71

From chemical Langevin equations to Fokker-Planck equation: application of Hodge decomposition and Klein-Kramers equation  

E-Print Network (OSTI)

The stochastic systems without detailed balance are common in various chemical reaction systems, such as metabolic network systems. In studies of these systems, the concept of potential landscape is useful. However, what are the sufficient and necessary conditions of the existence of the potential function is still an open problem. Use Hodge decomposition theorem in differential form theory, we focus on the general chemical Langevin equations, which reflect complex chemical reaction systems. We analysis the conditions for the existence of potential landscape of the systems. By mapping the stochastic differential equations to a Hamiltonian mechanical system, we obtain the Fokker-Planck equation of the chemical reaction systems. The obtained Fokker-Planck equation can be used in further studies of other steady properties of complex chemical reaction systems, such as their steady state entropies.

Mu, Weihua; Ou-Yang, Zhongcan

2010-01-01T23:59:59.000Z

72

On First-Order Generalized Maxwell Equations  

E-Print Network (OSTI)

The generalized Maxwell equations including an additional scalar field are considered in the first-order formalism. The gauge invariance of the Lagrangian and equations is broken resulting the appearance of a scalar field. We find the canonical and symmetrical Belinfante energy-momentum tensors. It is shown that the traces of the energy-momentum tensors are not equal to zero and the dilatation symmetry is broken in the theory considered. The matrix Hamiltonian form of equations is obtained after the exclusion of the nondynamical components. The canonical quantization is performed and the propagator of the fields is found in the first-order formalism.

S. I. Kruglov

2006-10-18T23:59:59.000Z

73

Thin Shell Dynamics and Equations of State  

E-Print Network (OSTI)

A relation between stress-energy and motion is derived for accelerated Israel layers. The relation, for layers between two Schwarzschild manifolds, generalizes the equation of state for geodesic collapse. A set of linked layers is discussed.

J. P. Krisch; E. N. Glass

2008-08-04T23:59:59.000Z

74

A Hamiltonian Approach to the Eikonal Equation  

Science Conference Proceedings (OSTI)

The eikonal equation and variants of it are of significant interest for problems in computer vision and image processing. It is the basis for continuous versions of mathematical morphology, stereo, shape-from-shading and for recent dynamic theories of ...

Kaleem Siddiqi; Allen Tannenbaum; Steven W. Zucker

1999-07-01T23:59:59.000Z

75

Linear Anelastic Equations for Atmospheric Vortices  

Science Conference Proceedings (OSTI)

A linear anelastic-vortex model is derived using assumptions appropriate to waves on vortices with scales similar to tropical cyclones. The equation set is derived through application of a multiple-scaling technique, such that the radial ...

Daniel Hodyss; David S. Nolan

2007-08-01T23:59:59.000Z

76

Free Solutions of the Barotropic Vorticity Equation  

Science Conference Proceedings (OSTI)

Using a variational procedure, we numerically search for steady solutions to the unforced, inviscid barotropic vorticity equation on the sphere. The algorithm produces many states that have extremely small tendencies within the triangular 15 ...

Grant Branstator; J. D. Opsteegh

1989-06-01T23:59:59.000Z

77

Empirical Master Equations. Part I: Numerical Properties  

Science Conference Proceedings (OSTI)

In the atmospheric sciences, master equations are mainly used in a discrete time approximation to provide forecasts of the probability density function in a discretized phase space spanned by a few climate variables. The coefficients of an ...

Mauro Dall’Amico; Joseph Egger

2007-09-01T23:59:59.000Z

78

The n-dimensional Laplace Equation - CECM  

E-Print Network (OSTI)

The n-dimensional Laplace equation is of the form: ... The systems for n = 3..16 can be downloaded here (the files in the archive are named laplace_n). It should  ...

79

Equations of Motion Using Thermodynamic Coordinates  

Science Conference Proceedings (OSTI)

The forms of the primitive equations of motion and continuity are obtained when an arbitrary thermodynamic state variable=mrestricted only to be vertically monotonic=mis used as the vertical coordinate. Natural generalizations of the Montgomery ...

Roland A. de Szoeke

2000-11-01T23:59:59.000Z

80

Solving general shallow wave equations on surfaces  

Science Conference Proceedings (OSTI)

We propose a new framework for solving General Shallow Wave Equations (GSWE) in order to efficiently simulate water flows on solid surfaces under shallow wave assumptions. Within this framework, we develop implicit schemes for solving the external forces ...

Huamin Wang; Gavin Miller; Greg Turk

2007-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

Numerical solution of the spray equation  

SciTech Connect

The spray equation has been solved numerically using a statistical approach. The method has been applied to physical systems where all three space coordinates are independent, in an internal combustion engine with asymmetric liquid fuel injection. For physical configurations in which some degree of symmetry exists, the numerical model is simplified, at a considerable savings in computer time. Difference equations are derived for the spray equation in one, two, and three dimensions. In three dimensions the equations are given in Cartesian and cylindrical coordinates. Quantities of physical interest which can be calculated from the droplet distribution function are defined. Coupling terms for use in combined spray-gas phase hydrodynamics models are derived, conserving the total mass, momentum, and energy of the two-phase system. The spray model is extended to allow for denser sprays in which the thin spray approximation is no longer valid.

Westbrook, C.K.

1976-11-01T23:59:59.000Z

82

Semilinear Hyperbolic Equations in Curved Spacetime  

E-Print Network (OSTI)

This is a survey of the author's recent work rather than a broad survey of the literature. The survey is concerned with the global in time solutions of the Cauchy problem for matter waves propagating in the curved spacetimes, which can be, in particular, modeled by cosmological models. We examine the global in time solutions of some class of semililear hyperbolic equations, such as the Klein-Gordon equation, which includes the Higgs boson equation in the Minkowski spacetime, de Sitter spacetime, and Einstein & de Sitter spacetime. The crucial tool for the obtaining those results is a new approach suggested by the author based on the integral transform with the kernel containing the hypergeometric function.\\\\ {\\bf Mathematics Subject Classification (2010):} Primary 35L71, 35L53; Secondary 81T20, 35C15.\\\\ {\\bf Keywords:} \\small {de Sitter spacetime; Klein-Gordon equation; Global solutions; Huygens' principle; Higuchi bound}

Karen Yagdjian

2013-05-19T23:59:59.000Z

83

Proof graphs for parameterised boolean equation systems  

Science Conference Proceedings (OSTI)

Parameterised Boolean equation systems (PBESs) can be used for solving a variety of verification problems such as model checking and equivalence checking problems. The definition of solution for a PBES is notoriously difficult to understand, which makes ...

Sjoerd Cranen, Bas Luttik, Tim A. C. Willemse

2013-08-01T23:59:59.000Z

84

Hierarchy of Mesoscale Flow Assumptions and Equations  

Science Conference Proceedings (OSTI)

The present research proposes a standard nomenclature for mesoscale meteorological concepts and integrates existing concepts of atmospheric space scales, flow assumptions, governing equations, and resulting motions into a hierarchy useful in ...

P. Thunis; R. Bornstein

1996-02-01T23:59:59.000Z

85

A Novel Image Denoising Algorithm Based on Anisotropic Diffusion Equation  

Science Conference Proceedings (OSTI)

This article first give the concept of the scale space, and construct the relationship between the heat conduction equation and the Gaussian scale space, which lead to the partial differential equations. Then the article introduces linear diffusion equation, ... Keywords: Anisotropic diffusion equation, image denoising, partial differential equation

Haozheng Ren Hongbo, Hongbo Yu, Yihua Lan

2013-08-01T23:59:59.000Z

86

Parallel Monte Carlo approach for integration of the rendering equation  

Science Conference Proceedings (OSTI)

This paper is addressed to the numerical solving of the rendering equation in realistic image creation. The rendering equation is integral equation describing the light propagation in a scene accordingly to a given illumination model. The used illumination ...

Ivan T. Dimov; Anton A. Penzov; Stanislava S. Stoilova

2006-08-01T23:59:59.000Z

87

A Method of Solving Certain Nonlinear Diophantine Equations  

E-Print Network (OSTI)

In this paper we propose a method of solving a Nonlinear Diophantine Equation by converting it into a System of Diophantine Linear Equations.

Florentin Smarandache

2009-10-12T23:59:59.000Z

88

Electrolux Gibson Air Conditioner and Equator Clothes Washer...  

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

Electrolux Gibson Air Conditioner and Equator Clothes Washer Fail DOE Energy Star Testing Electrolux Gibson Air Conditioner and Equator Clothes Washer Fail DOE Energy Star Testing...

89

Modified Friedmann scenario from the Wheeler-DeWitt equation  

SciTech Connect

We consider the possible modification of the Friedmann equation due to the operator ordering parameter entering the Wheeler-DeWitt equation.

Maziashvili, Michael [Department of Theoretical Physics, Tbilisi State University, 3 Chavchavadze Avenue, Tbilisi 0128 (Georgia)

2005-01-15T23:59:59.000Z

90

Chemical potential and the gap equation  

E-Print Network (OSTI)

In general the kernel of QCD's gap equation possesses a domain of analyticity upon which the equation's solution at nonzero chemical potential is simply obtained from the in-vacuum result through analytic continuation. On this domain the single-quark number- and scalar-density distribution functions are mu-independent. This is illustrated via two models for the gap equation's kernel. The models are alike in concentrating support in the infrared. They differ in the form of the vertex but qualitatively the results are largely insensitive to the Ansatz. In vacuum both models realise chiral symmetry in the Nambu-Goldstone mode and in the chiral limit, with increasing chemical potential, exhibit a first-order chiral symmetry restoring transition at mu~M(0), where M(p^2) is the dressed-quark mass function. There is evidence to suggest that any associated deconfinement transition is coincident and also of first-order.

Huan Chen; Wei Yuan; Lei Chang; Yu-Xin Liu; Thomas Klahn; Craig D. Roberts

2008-07-17T23:59:59.000Z

91

Maxwell's equations, linear gravity, and twistors  

SciTech Connect

A detailed outline is presented of several convergent points of view connecting the self-dual and anti-self-dual fields with their free data. This is doen for the Maxwell and for linearized gravity as exemplifying the approaches. The Sparling equation provides one tool of great power and characterizes one approach. The twistor theory of Penrose yields another equally powerful point of view. The links between these two basic approaches given in this paper provide a unification that allows workers and others with interest in this area to proceed more readily toward the goal of understanding the full nonlinear Einstein equations.

Kozameh, C.N.; Newman, E.T.; Porter, J.R.

1984-11-01T23:59:59.000Z

92

Weak Solutions for Dislocation Type Equations  

E-Print Network (OSTI)

We describe recent results obtained by G. Barles, P. Cardaliaguet, R. Monneau and the author recently. They are concerned with nonlocal Eikonal equations arising in the study of the dynamics of dislocation lines in crystals. These equations are nonlocal but also non monotone. We use a notion of weak solution to provide solutions for all time. Then, we discuss the link between these weak solutions and the classical viscosity solutions, and state some uniqueness results in particular cases. A counter-example to uniqueness is given.

Ley, Olivier

2008-01-01T23:59:59.000Z

93

Nonlinear conformal-degree preserving Dirac equations  

E-Print Network (OSTI)

Nonlinear Dirac equations in D+1 space-time are obtained by variation of the spinor action whose Lagrangian components have the same conformal degree and the coupling parameter of the self-interaction term is dimensionless. In 1+1 dimension, we show that these requirements result in the "conventional" quartic form of the nonlinear interaction and present the general equation for various coupling modes. These include, but not limited to, the Thirring and Gross-Neveu models. We obtain a numerical solution for the special case of the spin and pseudo-spin symmetric modes..

A. D. Alhaidari

2012-12-25T23:59:59.000Z

94

Large-angle Parabolic Equation Methods James T. Kirby*  

E-Print Network (OSTI)

CHAPTER 32 Large-angle Parabolic Equation Methods James T. Kirby* Large-angle parabolic equation of the parabolic equation method (PEM) to any relevant wave propagation problem implies that a principal is to examine two methods of extending the basic parabolic equation method to include large-angle effects

Kirby, James T.

95

Is There a Nonrecursive Decidable Equational Theory?  

Science Conference Proceedings (OSTI)

The Church-Turing Thesis (CTT) is often paraphrased as ``every computable function is computable by means of a Turing machine.'' The author has constructed a family of equational theories that are not Turing-decidable, that is, given one of the theories, ... Keywords: Church-Turing Thesis, Turing decidability, effective procedure, pseudorecursive theory, quotidian procedure

Benjamin Wells

2002-05-01T23:59:59.000Z

96

THE MULTIGROUP DIFFUSION EQUATIONS OF REACTOR PHYSICS  

SciTech Connect

The partial differential equations of the multigroup diffusion model of reactor physics are shown to have solutions both in the time-independent and timedependent problems, and the usually assumed behavior of these solutions is shown to be mathematically valid. The method of spectral representation is developed for the multigroup diffusion operator. (auth)

Habetler, G.J.; Martino, M.A.

1958-07-28T23:59:59.000Z

97

GALERKIN SPECTRAL SYNTHESIS METHODS FOR DIFFUSION EQUATIONS  

E-Print Network (OSTI)

di#usion approximation to nuclear reactor problems. Such methods consist of all tech­ niques in which An existence and uniqueness theory is developed for the energy dependent, steady state neutron di#usion equation with inhomogeneous oblique boundary conditions im­ posed. Also, a convergence theory is developed

Neta, Beny

98

A numerical methodology for the Painlevé equations  

Science Conference Proceedings (OSTI)

The six Painleve transcendents P"I-P"V"I have both applications and analytic properties that make them stand out from most other classes of special functions. Although they have been the subject of extensive theoretical investigations for about a century, ... Keywords: Chebyshev collocation method, PI equation, Padé approximation, Painlevé transcendents, Taylor series method

Bengt Fornberg; J. A. C. Weideman

2011-07-01T23:59:59.000Z

99

Equation of state and singularities in FLRW cosmological models  

E-Print Network (OSTI)

We consider FLRW cosmological models with standard Friedmann equations, but leaving free the equation of state. We assume that the dark energy content of the universe is encoded in an equation of state $p=f(\\rho)$, which is expressed with most generality in the form of a power expansion. The inclusion of this expansion in Friedmann equations allows us to construct a perturbative solution and to relate the coefficients of the equation of state with the formation of singularities of different types.

L. Fernandez-Jambrina; R. Lazkoz

2010-01-18T23:59:59.000Z

100

Second kind integral equations for the first kind Dirichlet problem of the biharmonic equation in three dimensions  

Science Conference Proceedings (OSTI)

A Fredholm second kind integral equation (SKIE) formulation is constructed for the Dirichlet problem of the biharmonic equation in three dimensions. A fast numerical algorithm is developed based on the constructed SKIE. Its performance is illustrated ... Keywords: Biharmonic equation, Dirichlet problem, Second kind integral equation

Shidong Jiang; Bo Ren; Paul Tsuji; Lexing Ying

2011-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

Reflection in membership equational logic, many-sorted equational logic, Horn logic with equality, and rewriting logic  

Science Conference Proceedings (OSTI)

We show that the generalized variant of formal systems where the underlying equational specifications are membership equational theories, and where the rules are conditional and can have equations, memberships and rewrites in the conditions is reflective. ... Keywords: Maude, Membership equational logic, Reflection, Reflective logics, Reflective programming languages, Rewriting logic, Universal theories

Manuel Clavel; José Meseguer; Miguel Palomino

2007-03-01T23:59:59.000Z

102

A cartesian grid embedded boundary method for the heat equation and poisson's equation in three dimensions  

E-Print Network (OSTI)

A Cartesian grid embedded boundary method for the heatA Cartesian Grid Embedded Boundary Method for the HeatError Grid Size Fig. 17. Solution error for heat equation on

Schwartz, Peter; Barad, Michael; Colella, Phillip; Ligocki, Terry

2004-01-01T23:59:59.000Z

103

Solutions of Jimbo-Miwa Equation and Konopelchenko-Dubrovsky Equations  

Science Conference Proceedings (OSTI)

The Jimbo-Miwa equation is the second equation in the well known KP hierarchy of integrable systems, which is used to describe certain interesting (3+1)-dimensional waves in physics but not pass any of the conventional integrability tests. The Konopelchenko-Dubrovsky ... Keywords: 35C10, 35C15, 35Q51, Jimbo-Miwa, Konopelchenko-Dubrovsky, Logarithmic stable-range, Stable-range

Bintao Cao

2010-11-01T23:59:59.000Z

104

Shape Metamorphism Using p-Laplacian Equation  

SciTech Connect

We present a new approach for shape metamorphism, which is a process of gradually changing a source shape (known) through intermediate shapes (unknown) into a target shape (known). The problem, when represented with implicit scalar function, is under-constrained, and regularization is needed. Using the p-Laplacian equation (PLE), we generalize a series of regularization terms based on the gradient of the implicit function, and we show that the present methods lack additional constraints for a more stable solution. The novelty of our approach is in the deployment of a new regularization term when p --> infinity which leads to the infinite Laplacian equation (ILE). We show that ILE minimizes the supremum of the gradient and prove that it is optimal for metamorphism since intermediate solutions are equally distributed along their normal direction. Applications of the proposed algorithm for 2D and 3D objects are demonstrated.

Cong, Ge; Esser, Mehmet; Parvin, Bahram; Bebis, George

2004-05-19T23:59:59.000Z

105

Solving Partial Differential Equations on Overlapping Grids  

SciTech Connect

We discuss the solution of partial differential equations (PDEs) on overlapping grids. This is a powerful technique for efficiently solving problems in complex, possibly moving, geometry. An overlapping grid consists of a set of structured grids that overlap and cover the computational domain. By allowing the grids to overlap, grids for complex geometries can be more easily constructed. The overlapping grid approach can also be used to remove coordinate singularities by, for example, covering a sphere with two or more patches. We describe the application of the overlapping grid approach to a variety of different problems. These include the solution of incompressible fluid flows with moving and deforming geometry, the solution of high-speed compressible reactive flow with rigid bodies using adaptive mesh refinement (AMR), and the solution of the time-domain Maxwell's equations of electromagnetism.

Henshaw, W D

2008-09-22T23:59:59.000Z

106

Iterative solutions to the Dirac equation  

E-Print Network (OSTI)

We consider a single particle which is bound by a central potential and obeys the Dirac equation in d dimensions. We first apply the asymptotic iteration method to recover the known exact solutions for the pure Coulomb case. For a screened-Coulomb potential and for a Coulomb plus linear potential with linear scalar confinement, the method is used to obtain accurate approximate solutions for both eigenvalues and wave functions.

Hakan Ciftci; Richard L. Hall; Nasser Saad

2005-05-26T23:59:59.000Z

107

Multicomponent Modified Boltzmann Equation and Thermalization  

E-Print Network (OSTI)

The existence of stationary distributions in a multicomponent Boltzmann equation using a non-additive kinetic energy composition rule for binary collisions is discussed. It is found that detailed balance is not achieved when -- in contrast to the case of a single rule -- several different composition rules are considered. The long-time behaviour of a simple momentum space model is explored numerically: saturating, heating and cooling solutions are presented.

M. Horváth; T. S. Biró

2013-09-19T23:59:59.000Z

108

Laguerre method to solve parton evolution equations  

SciTech Connect

The DGLAP evolution equations for non-singlet sector of parton density is solved in x-space based on Laguerre polynomial expansion. High numerical accuracy is achieved by expanding over a set of approximately 30 polynomials. The result of evolved parton densities to high energy scales are in good agreement with phenomenological GRV model. To improve the results we can employ a constituent quark model.

Mirjalili, A. [Physics Department, Yazd University, P.O.B. 89195-741, Yazd (Iran, Islamic Republic of); School of Particles and Accelerators (IPM), Institute for Research in Fundamental Sciences, 19395-5531, Tehran (Iran, Islamic Republic of); Yazdanpanah, M. M. [Physics Department, Shahid-Bahonar University, Kerman (Iran, Islamic Republic of); School of Particles and Accelerators (IPM), Institute for Research in Fundamental Sciences, 19395-5531, Tehran (Iran, Islamic Republic of); Sharifinejad, H. R. [Physics Department, Yazd University, P.O.B. 89195-741, Yazd (Iran, Islamic Republic of)

2011-05-23T23:59:59.000Z

109

Optimal Control of Stochastic Partial Differential Equations  

E-Print Network (OSTI)

In this paper, we prove the necessary and sufficient maximum principles (NSMP in short) for the optimal control of system described by a quasilinear stochastic heat equation with the control domain being convex and all the coefficients containing control variable. For that, the optimal control problem of fully coupled forward-backward doubly stochastic system is studied. We apply our NSMP to solve a kind of forward-backward doubly stochastic linear quadratic optimal control problem as well.

Zhang, Liangquan

2010-01-01T23:59:59.000Z

110

Extensions of the longitudinal envelope equation  

DOE Green Energy (OSTI)

Recently, longitudinal space charge effects have become of increased importance in a variety of dynamical situations. The CEBAF FEL injector beam dynamics shows large space-charge effects, even at 10 MeV ({gamma} {approx} 20). Space-charge dominated longitudinal motion has also been studied in the IUCF ion storage ring. Previously a longitudinal envelope equation with a self-consistent phase-space distribution has been developed, and has been of considerable use in analyzing the motion of these cases. Longitudinal motion in detailed agreement with this envelope equation has been observed at the U. of Maryland Laboratory for Plasma Research, and at the GSI electron cooling storage ring ESR, as well as at the IUCF. However, the initial presentation in ref. 4 used non-relativistic linear-accelerator bunching motion as a simplifying approximation in order to avoid inadvertent errors and minimize misprints, and must be adapted to include relativistic and/or synchrotron effects. In the present note we extend the envelope equation formulae to include relativistic, synchrotron, and acceleration effects, and define the various factors in the equations in explicit detail. The object is to obtain a set of debugged formulae for these extended cases, with all of the various factors defined explicitly, so that the formulae can be used as a reference without repetitive rederivations. The usual ambiguities over emittance definitions and units and {beta}, {gamma}, g factors should be resolved. The reader (or readers) is invited to discover any remaining errors, ambiguities or misprints for removal in the next edition.

Neuffer, David

1997-04-30T23:59:59.000Z

111

Dirac equation in terms of hydrodynamic variables  

E-Print Network (OSTI)

The distributed system $\\mathcal{S}_D$ described by the Dirac equation is investigated simply as a dynamic system, i.e. without usage of quantum principles. The Dirac equation is described in terms of hydrodynamic variables: 4-flux $j^{i}$, pseudo-vector of the spin $S^{i}$, an action $\\hbar \\phi $ and a pseudo-scalar $\\kappa $. In the quasi-uniform approximation, when all transversal derivatives (orthogonal to the flux vector $j^i$) are small, the system $\\mathcal{S}_D$ turns to a statistical ensemble of classical concentrated systems $\\mathcal{S}_{dc}$. Under some conditions the classical system $\\mathcal{S}_{dc}$ describes a classical pointlike particle moving in a given electromagnetic field. In general, the world line of the particle is a helix, even if the electromagnetic field is absent. Both dynamic systems $\\mathcal{S}_D$ and $\\mathcal{S}_{dc}$ appear to be non-relativistic in the sense that the dynamic equations written in terms of hydrodynamic variables are not relativistically covariant with respect to them, although all dynamic variables are tensors or pseudo-tensors. They becomes relativistically covariant only after addition of a constant unit timelike vector $f^{i}$ which should be considered as a dynamic variable describing a space-time property. This "constant" variable arises instead of $\\gamma $-matrices which are removed by means of zero divizors in the course of the transformation to hydrodynamic variables. It is possible to separate out dynamic variables $\\kappa $, $\\kappa ^i$ responsible for quantum effects. It means that, setting $\\kappa ,\\kappa ^i\\equiv 0$, the dynamic system $\\mathcal{S}_D$ described by the Dirac equation turns to a statistical ensemble $\\mathcal{E}_{Dqu}$ of classical dynamic systems $\\mathcal{S}_{dc}$.

Yuri A. Rylov

2011-01-31T23:59:59.000Z

112

The quasicontinuum Fokker-Plank equation  

Science Conference Proceedings (OSTI)

We present a regularized Fokker-Planck equation with more accurate short-time and high-frequency behavior for continuous-time, discrete-state systems. The regularization preserves crucial aspects of state-space discreteness lost in the standard Kramers-Moyal expansion. We apply the method to a simple example of biochemical reaction kinetics and to a two-dimensional symmetric random walk, and suggest its application to more complex systerns.

Alexander, Francis J [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

113

Measuring the dark matter equation of state  

E-Print Network (OSTI)

The nature of the dominant component of galaxies and clusters remains unknown. While the astrophysics community supports the cold dark matter (CDM) paradigm as a clue factor in the current cosmological model, no direct CDM detections have been performed. Faber and Visser 2006 have suggested a simple method for measuring the dark matter equation of state that combines kinematic and gravitational lensing data to test the widely adopted assumption of pressureless dark matter. Following this formalism, we have measured the dark matter equation of state for first time using improved techniques. We have found that the value of the equation of state parameter is consistent with pressureless dark matter within the errors. Nevertheless, the measured value is lower than expected because typically the masses determined with lensing are larger than those obtained through kinematic methods. We have tested our techniques using simulations and we have also analyzed possible sources of error that could invalidate or mimic our results. In the light of this result, we can now suggest that the understanding of the nature of dark matter requires a complete general relativistic analysis.

Ana Laura Serra; Mariano Javier de León Domínguez Romero

2011-03-28T23:59:59.000Z

114

Guiding Center Equations for Ideal Magnetohydrodynamic Modes  

SciTech Connect

Guiding center simulations are routinely used for the discovery of mode-particle resonances in tokamaks, for both resistive and ideal instabilities and to find modifications of particle distributions caused by a given spectrum of modes, including large scale avalanches during events with a number of large amplitude modes. One of the most fundamental properties of ideal magnetohydrodynamics is the condition that plasma motion cannot change magnetic topology. The conventional representation of ideal magnetohydrodynamic modes by perturbing a toroidal equilibrium field through ?~B = ? X (? X B) however perturbs the magnetic topology, introducing extraneous magnetic islands in the field. A proper treatment of an ideal perturbation involves a full Lagrangian displacement of the field due to the perturbation and conserves magnetic topology as it should. In order to examine the effect of ideal magnetohydrodynamic modes on particle trajectories the guiding center equations should include a correct Lagrangian treatment. Guiding center equations for an ideal displacement ? are derived which perserve the magnetic topology and are used to examine mode particle resonances in toroidal confinement devices. These simulations are compared to others which are identical in all respects except that they use the linear representation for the field. Unlike the case for the magnetic field, the use of the linear field perturbation in the guiding center equations does not result in extraneous mode particle resonances.

Roscoe B. White

2013-02-21T23:59:59.000Z

115

Conservation laws for self-adjoint ?rst order evolution equations  

E-Print Network (OSTI)

In this work we consider the problem on group classification and conservation laws of the general first order evolution equations. We obtain the subclasses of these general equations which are quasi-self-adjoint and self-adjoint. By using the recent Ibragimov's Theorem on conservation laws, we establish the conservation laws of the equations admiting self-adjoint equations. We illustrate our results applying them to the inviscid Burgers' equation. In particular an infinite number of new symmetries of these equations are found and their corresponding conservation laws are established.

Igor Leite Freire

2010-02-21T23:59:59.000Z

116

Traversable wormholes supported by cosmic accelerated expanding equations of state  

E-Print Network (OSTI)

We explore the possibility that traversable wormholes be supported by specific equations of state responsible for the present accelerated expansion of the Universe, namely, phantom energy, the generalized Chaplygin gas, and the van der Waals quintessence equation of state.

Francisco S. N. Lobo

2006-11-29T23:59:59.000Z

117

Structural Stability of the Coalescence/Breakup Equation  

Science Conference Proceedings (OSTI)

An analysis of the structural stability of the coalescence/breakup equation is performed to determine the degree to which changes in the equation's formulation can affect the solution. The work was motivated by speculation in various quarters ...

Philip S. Brown Jr.

1995-11-01T23:59:59.000Z

118

Row-Action Inversion of the Barrick–Weber Equations  

Science Conference Proceedings (OSTI)

The Barrick–Weber equations describe the interaction of radar signals with the dynamic ocean surface, and so provide a mathematical basis for oceanic remote sensing. This report considers the inversion of these equations with several of the row-...

J. J. Green; L. R. Wyatt

2006-03-01T23:59:59.000Z

119

A Simple Equation for Regional Climate Change and Associated Uncertainty  

Science Conference Proceedings (OSTI)

Simple equations are developed to express regional climate changes for the twenty-first century and associated uncertainty in terms of the global temperature change (GTC) without a dependence on the underlying emission pathways. The equations are ...

Filippo Giorgi

2008-04-01T23:59:59.000Z

120

Iterative solution of elliptic difference equations using fast direct methods  

Science Conference Proceedings (OSTI)

In recent years, fast direct methods have been developed for the numerical solution of the Poisson equation on a rectangle. By taking advantage of the special block structure of the approximating discrete equation on a uniform rectangular mesh, these ...

Paul Concus

1972-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

Another Look at the Thermodynamic Equation For Deep Convection  

Science Conference Proceedings (OSTI)

The study considers deep moist convection involving only a liquid-vapor phase change. An alternative form of the classical thermodynamic equation for reversible saturated flow is derived. Four approximate forms of this equation are obtained and ...

Frank B. Lipps; Richard S. Hemler

1980-01-01T23:59:59.000Z

122

Axisymmetric, Primitive Equation, Spectral Tropical Cyclone Model. Part I: Formulation  

Science Conference Proceedings (OSTI)

Beginning with the nine nonlinear governing equations for the simplest three-layer, axisymmetric, primitive equation, tropical cyclone model, we first introduce a vertical transform which decouples the linear part of the dynamics into three sets (...

Wayne H. Schubert; Mark DeMaria

1985-06-01T23:59:59.000Z

123

Notes 01. The fundamental assumptions and equations of lubrication theory  

E-Print Network (OSTI)

The fundamental assumption in Lubrication Theory. Derivation of thin film flow equations from Navier-Stokes equations. Importance of fluid inertia effects in thin film flows. Some fluid physical properties

San Andres, Luis

2009-01-01T23:59:59.000Z

124

Runge-Kutta Discontinuous Galerkin method for the Boltzmann equation  

E-Print Network (OSTI)

In this thesis we investigate the ability of the Runge-Kutta Discontinuous Galerkin (RKDG) method to provide accurate and efficient solutions of the Boltzmann equation. Solutions of the Boltzmann equation are desirable in ...

Lui, Ho Man

2006-01-01T23:59:59.000Z

125

Derivation of new 3D discrete ordinate equations  

Science Conference Proceedings (OSTI)

The Sn equations have been the workhorse of deterministic radiation transport calculations for many years. Here we derive two new angular discretizations of the 3D transport equation. The first set of equations, derived using Lagrange interpolation and collocation, retains the classical Sn structure, with the main difference being how the scattering source is calculated. Because of the formal similarity with the classical S n equations, it should be possible to modify existing computer codes to take advantage of the new formulation. In addition, the new S n-like equations correctly capture delta function scattering. The second set of equations, derived using a Galerkin technique, does not retain the classical Sn structure because the streaming term is not diagonal. However, these equations can be cast into a form similar to existing methods developed to reduce ray effects. Numerical investigation of both sets of equations is under way. (authors)

Ahrens, C. D. [Colorado School of Mines, Dept. of Applied Mathematics and Statistics, Program in Nuclear Science and Engineering, Golden, CO 80401-1887 (United States)

2012-07-01T23:59:59.000Z

126

New Equations for Computing Vapor Pressure and Enhancement Factor  

Science Conference Proceedings (OSTI)

Equations are presented which relate saturation vapor pressure to temperature for moist air. The equations are designed to be easily implemented on a calculator or computer and can be used to convert in either direction. They are more accurate ...

Arden L. Buck

1981-12-01T23:59:59.000Z

127

A Convergent Method for Solving the Balance Equation  

Science Conference Proceedings (OSTI)

A well known method for the solution of the balance equation is analyzed. It is shown that the method is convergent, provided that under-relaxation is used and that the approximate solutions satisfy the ellipticity criteria of the equation.

Trond Iversen; Thor Erik Nordeng

1982-10-01T23:59:59.000Z

128

Transformations of Heun's equation and its integral relations  

E-Print Network (OSTI)

We find transformations of variables which preserve the form of the equation for the kernels of integral relations among solutions of the Heun equation. These transformations lead to new kernels for the Heun equation, given by single hypergeometric functions (Lambe-Ward-type kernels) and by products of two hypergeometric functions (Erd\\'elyi-type). Such kernels, by a limiting process, also afford new kernels for the confluent Heun equation.

Léa Jaccoud El-Jaick; Bartolomeu D. B. Figueiredo

2010-02-24T23:59:59.000Z

129

The theory of relaxation oscillations for Hutchinson's equation  

SciTech Connect

Hutchinson's equation is a scalar equation with time delay which is well known in ecology. In this paper a complete asymptotic representation is constructed for a stable relaxation cycle of this equation, in the form of series in integer powers of a certain small parameter. The techniques of asymptotic integration developed on the way are then applied to analyse the question of attractors for a system of circularly interrelated Hutchinson equations. Bibliography: 8 titles.

Kolesov, Andrei Yu; Rozov, Nikolai Kh

2011-06-30T23:59:59.000Z

130

Group classification for the nonlinear heat conductivity equation  

E-Print Network (OSTI)

Symmetry properties of the nonlinear heat conductivity equations of the general form $u_t=[E(x,u)u_x]_x + H(x,u)$ is studied. The point symmetry analysis of these equations is considered as well as an equivalence classification which admits an extension by one dimension of the principal Lie algebra of the equation. The invariant solutions of equivalence transformations and classification of the nonlinear heat conductivity equations among with additional operators are also given.

Mahdipour-Shirayeh, Ali

2009-01-01T23:59:59.000Z

131

The equation of motion of an electron  

SciTech Connect

We review the current status of understanding of the equation of motion of an electron. Classically, a consistent, linearized theory exists for an electron of finite extent, as long as the size of the electron is larger than the classical electron radius. Nonrelativistic quantum mechanics seems to offer a fine theory even in the point particle limit. Although there is as yet no convincing calculation, it is probable that a quantum electrodynamical result will be at least as well-behaved as is the nonrelativistic quantum mechanical results. {copyright} {ital 1999 American Institute of Physics.}

Kim, K. [Argonne National Laboratory, Argonne, Illinois 60439 and The University of Chicago, Chicago, Illinois 60637 (United States); Sessler, A.M. [Lawrence Berkeley National Laboratory, Berkeley, California 94720 (United States)

1999-07-01T23:59:59.000Z

132

The equation of motion of an electron.  

SciTech Connect

We review the current status of understanding of the equation of motion of an electron. Classically, a consistent linearized theory exists for an electron of finite extent, as long as the size of the electron is larger than the classical electron radius. Nonrelativistic quantum mechanics seems to offer a fine theory even in the point particle limit. Although there is as yet no convincing calculation, it is probable that a quantum electrodynamical result will be at least as well-behaved as is the nonrelativistic quantum mechanical results.

Kim, K.-J.

1998-09-02T23:59:59.000Z

133

Numerical Schemes for Rough Parabolic Equations  

SciTech Connect

This paper is devoted to the study of numerical approximation schemes for a class of parabolic equations on (0,1) perturbed by a non-linear rough signal. It is the continuation of Deya (Electron. J. Probab. 16:1489-1518, 2011) and Deya et al. (Probab. Theory Relat. Fields, to appear), where the existence and uniqueness of a solution has been established. The approach combines rough paths methods with standard considerations on discretizing stochastic PDEs. The results apply to a geometric 2-rough path, which covers the case of the multidimensional fractional Brownian motion with Hurst index H>1/3.

Deya, Aurelien, E-mail: deya@iecn.u-nancy.fr [Universite de Nancy 1, Institut Elie Cartan Nancy (France)

2012-04-15T23:59:59.000Z

134

Lorentz Transformation Equations in Galilean Form  

E-Print Network (OSTI)

Using the notion, developed in an earlier paper, of "representation" of "position" by a vector in a vector space with an inner product, we show that the Lorentz Transformation Equations relating positions in two different reference frames can be put in a particularly simple form which could be said to be "Galilean". We emphasize that two different reference frames can use a common vector space for representation but with two different inner products. The inner products are defined through the observational set-up of each frame.

S. D. Agashe

2010-02-03T23:59:59.000Z

135

Stability of Partial Functional Integro-Differential Equations  

Science Conference Proceedings (OSTI)

Using the Fourier method of separation of variables and a procedure proposed in this paper, namely, reducing integrodifferential equations to systems of ordinary differential equations, the exponential stability of partial functional integro-differential ... Keywords: Cauchy matrix, Functional differential equations, exponential stability, phase transition model

R. P. Agarwal; A. Domoshnitsky; Ya. Goltser

2006-01-01T23:59:59.000Z

136

FINITE DIFFERENCE METHODS FOR THE WIDE-ANGLE `PARABOLIC' EQUATION  

E-Print Network (OSTI)

FINITE DIFFERENCE METHODS FOR THE WIDE-ANGLE `PARABOLIC' EQUATION GEORGIOS AKRIVIS Abstract. We consider a model initial and boundary value problem for the wide-angle `parabolic' equation Lur = icu, the wide-angle `parabolic'equation of underwater acoustics. Given R > 0, µ 0, > 0, , and q real

Akrivis, Georgios

137

Algebraic Approaches to the geopotential Forecast and Nonlinear MHD Equations  

E-Print Network (OSTI)

In this paper, we use various anstazes motivated from our earlier works on transonic gas flows, boundary layer problems and Navier-Stokes equations to find new explicit exact solutions with multiple parameter functions for the equation of geopotential forecast and the equations of nonlinear magnetohydrodynamics.

Xiaoping Xu

2008-11-23T23:59:59.000Z

138

Effective equations for the quantum pendulum from momentous quantum mechanics  

SciTech Connect

In this work we study the quantum pendulum within the framework of momentous quantum mechanics. This description replaces the Schroedinger equation for the quantum evolution of the system with an infinite set of classical equations for expectation values of configuration variables, and quantum dispersions. We solve numerically the effective equations up to the second order, and describe its evolution.

Hernandez, Hector H.; Chacon-Acosta, Guillermo [Universidad Autonoma de Chihuahua, Facultad de Ingenieria, Nuevo Campus Universitario, Chihuahua 31125 (Mexico); Departamento de Matematicas Aplicadas y Sistemas, Universidad Autonoma Metropolitana-Cuajimalpa, Artificios 40, Mexico D. F. 01120 (Mexico)

2012-08-24T23:59:59.000Z

139

Building Blocks for Computer Vision with Stochastic Partial Differential Equations  

Science Conference Proceedings (OSTI)

We discuss the basic concepts of computer vision with stochastic partial differential equations (SPDEs). In typical approaches based on partial differential equations (PDEs), the end result in the best case is usually one value per pixel, the "expected" ... Keywords: Error propagation, Image processing, Polynomial chaos, Random fields, Stochastic Galerkin method, Stochastic finite element method, Stochastic partial differential equations

Tobias Preusser; Hanno Scharr; Kai Krajsek; Robert M. Kirby

2008-12-01T23:59:59.000Z

140

Using the scalable nonlinear equations solvers package  

SciTech Connect

SNES (Scalable Nonlinear Equations Solvers) is a software package for the numerical solution of large-scale systems of nonlinear equations on both uniprocessors and parallel architectures. SNES also contains a component for the solution of unconstrained minimization problems, called SUMS (Scalable Unconstrained Minimization Solvers). Newton-like methods, which are known for their efficiency and robustness, constitute the core of the package. As part of the multilevel PETSc library, SNES incorporates many features and options from other parts of PETSc. In keeping with the spirit of the PETSc library, the nonlinear solution routines are data-structure-neutral, making them flexible and easily extensible. This users guide contains a detailed description of uniprocessor usage of SNES, with some added comments regarding multiprocessor usage. At this time the parallel version is undergoing refinement and extension, as we work toward a common interface for the uniprocessor and parallel cases. Thus, forthcoming versions of the software will contain additional features, and changes to parallel interface may result at any time. The new parallel version will employ the MPI (Message Passing Interface) standard for interprocessor communication. Since most of these details will be hidden, users will need to perform only minimal message-passing programming.

Gropp, W.D.; McInnes, L.C.; Smith, B.F.

1995-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

Generalized finite element method for Helmholtz equation  

E-Print Network (OSTI)

This dissertation presents the Generalized Finite Element Method (GFEM) for the scalar Helmholtz equation, which describes the time harmonic acoustic wave propagation problem. We introduce several handbook functions for the Helmholtz equation, namely the planewave, wave-band, and Vekua functions, and we use these handbook functions to enrich the Finite Element space via the Partition of Unity Method to create the GFEM space. The enrichment of the approximation space by these handbook functions reduces the pollution effect due to wave number and we are able to obtain a highly accurate solution with a much smaller number of degrees-of-freedom compared with the classical Finite Element Method. The q-convergence of the handbook functions is investigated, where q is the order of the handbook function, and it is shown that asymptotically the handbook functions exhibit the same rate of exponential convergence. Hence we can conclude that the selection of the handbook functions from an admissible set should be dictated only by the ease of implementation and computational costs. Another issue addressed in this dissertation is the error coming from the artificial truncation boundary condition, which is necessary to model the Helmholtz problem set in the unbounded domain. We observe that for high q, the most significant component of the error is the one due to the artificial truncation boundary condition. Here we propose a method to assess this error by performing an additional computation on the extended domain using GFEM with high q.

Hidajat, Realino Lulie

2007-05-01T23:59:59.000Z

142

Integral equations for the H- X- and Y-functions  

E-Print Network (OSTI)

We come back to a non linear integral equation satisfied by the function H, which is distinct from the classical H-equation. Established for the first time by Busbridge (1955), it appeared occasionally in the literature since then. First of all, this equation is generalized over the whole complex plane using the method of residues. Then its counterpart in a finite slab is derived; it consists in two series of integral equations for the X- and Y-functions. These integral equations are finally applied to the solution of the albedo problem in a slab.

B. Rutily; L. Chevallier; J. Bergeat

2006-01-16T23:59:59.000Z

143

On k-jet field approximations of geodesic deviation equations  

E-Print Network (OSTI)

Let M be a smooth manifold and S a spray defined on the convex cone C of the tangent bundle TM. It is proved that the only non-trivial k-jet approximation of the exact geodesic deviation equation of S, linear on the deviation functions and invariant under arbitrary local coordinate transformations corresponds to the Jacobi equation. However, if linearity in the deviation functions is not required, there are differential equations whose solutions admit k-jet approximations and are invariant under arbitrary coordinate transformations. As an example of higher order geodesic deviation equations we study the first and second order jet geodesic deviation equations for a Finsler spray.

Torromé, Ricardo Gallego

2013-01-01T23:59:59.000Z

144

A Hierarchy of Approximations of the Master Equation Scaled by a Size Parameter  

Science Conference Proceedings (OSTI)

Solutions of the master equation are approximated using a hierarchy of models based on the solution of ordinary differential equations: the macroscopic equations, the linear noise approximation and the moment equations. The advantage with the approximations ... Keywords: Linear noise approximation, Master equation, Moment equations, Reaction rate equations

Lars Ferm; Per Lötstedt; Andreas Hellander

2008-02-01T23:59:59.000Z

145

Bounding biomass in the Fisher equation  

E-Print Network (OSTI)

The FKPP equation with a variable growth rate and advection by an incompressible velocity field is considered as a model for plankton dispersed by ocean currents. If the average growth rate is negative then the model has a survival-extinction transition; the location of this transition in the parameter space is constrained using variational arguments and delimited by simulations. The statistical steady state reached when the system is in the survival region of parameter space is characterized by integral constraints and upper and lower bounds on the biomass and productivity that follow from variational arguments and direct inequalities. In the limit of zero-decorrelation time the velocity field is shown to act as Fickian diffusion with an eddy diffusivity much larger than the molecular diffusivity and this allows a one-dimensional model to predict the biomass, productivity and extinction transitions. All results are illustrated with a simple growth and stirring model.

Daniel A. Birch; Yue-Kin Tsang; William R. Young

2007-03-17T23:59:59.000Z

146

Emergence of wave equations from quantum geometry  

SciTech Connect

We argue that classical geometry should be viewed as a special limit of noncommutative geometry in which aspects which are inter-constrained decouple and appear arbitrary in the classical limit. In particular, the wave equation is really a partial derivative in a unified extra-dimensional noncommutative geometry and arises out of the greater rigidity of the noncommutative world not visible in the classical limit. We provide an introduction to this 'wave operator' approach to noncommutative geometry as recently used[27] to quantize any static spacetime metric admitting a spatial conformal Killing vector field, and in particular to construct the quantum Schwarzschild black hole. We also give an introduction to our related result that every classical Riemannian manifold is a shadow of a slightly noncommutative one wherein the meaning of the classical Ricci tensor becomes very natural as the square of a generalised braiding.

Majid, Shahn [School of Mathematical Sciences, Queen Mary University of London, 327 Mile End Rd, London E1 4NS (United Kingdom)

2012-09-24T23:59:59.000Z

147

Bounding biomass in the Fisher equation  

E-Print Network (OSTI)

The FKPP equation with a variable growth rate and advection by an incompressible velocity field is considered as a model for plankton dispersed by ocean currents. If the average growth rate is negative then the model has a survival-extinction transition; the location of this transition in the parameter space is constrained using variational arguments and delimited by simulations. The statistical steady state reached when the system is in the survival region of parameter space is characterized by integral constraints and upper and lower bounds on the biomass and productivity that follow from variational arguments and direct inequalities. In the limit of zero-decorrelation time the velocity field is shown to act as Fickian diffusion with an eddy diffusivity much larger than the molecular diffusivity and this allows a one-dimensional model to predict the biomass, productivity and extinction transitions. All results are illustrated with a simple growth and stirring model.

Birch, Daniel A; Young, William R

2007-01-01T23:59:59.000Z

148

Assessment of UF6 Equation of State  

SciTech Connect

A common assumption in the mathematical analysis of flows of compressible fluids is to treat the fluid as a perfect gas. This is an approximation, as no real fluid obeys the perfect gas relationships over all temperature and pressure conditions. An assessment of the validity of treating the UF{sub 6} gas flow field within a gas centrifuge with perfect gas relationships has been conducted. The definition of a perfect gas is commonly stated in two parts: (1) the gas obeys the thermal equation of state, p = {rho}RT (thermally perfect), and, (2) the gas specific heats are constant (calorically perfect). Analysis indicates the thermally perfect assumption is valid for all flow conditions within the gas centrifuge, including shock fields. The low operating gas pressure is the primary factor in the suitability of the thermally perfect equation of state for gas centrifuge computations. UF{sub 6} is not calorically perfect, as the specific heats vary as a function of temperature. This effect is insignificant within the bulk of the centrifuge gas field, as gas temperatures vary over a narrow range. The exception is in the vicinity of shock fields, where temperature, pressure, and density gradients are large, and the variation of specific heats with temperature should be included in the technically detailed analyses. Results from a normal shock analysis incorporating variable specific heats is included herein, presented in the conventional form of shock parameters as a function of inlet Mach Number. The error introduced by assuming constant specific heats is small for a nominal UF{sub 6} shock field, such that calorically perfect shock relationships can be used for scaling and initial analyses. The more rigorous imperfect gas analysis should be used for detailed analyses.

Brady, P; Chand, K; Warren, D; Vandersall, J

2009-02-11T23:59:59.000Z

149

Consistent description of kinetic equation with triangle anomaly  

SciTech Connect

We provide a consistent description of the kinetic equation with a triangle anomaly which is compatible with the entropy principle of the second law of thermodynamics and the charge/energy-momentum conservation equations. In general an anomalous source term is necessary to ensure that the equations for the charge and energy-momentum conservation are satisfied and that the correction terms of distribution functions are compatible to these equations. The constraining equations from the entropy principle are derived for the anomaly-induced leading order corrections to the particle distribution functions. The correction terms can be determined for the minimum number of unknown coefficients in one charge and two charge cases by solving the constraining equations.

Pu Shi; Gao Jianhua; Wang Qun [Interdisciplinary Center for Theoretical Study and Department of Modern Physics, University of Science and Technology of China, Hefei 230026 (China)

2011-05-01T23:59:59.000Z

150

Non-autonomous stochastic evolution equations and applications to stochastic partial differential equations  

E-Print Network (OSTI)

In this paper we study the following non-autonomous stochastic evolution equation on a UMD Banach space $E$ with type 2, \\begin{equation}\\label{eq:SEab}\\tag{SE} {\\begin{aligned} dU(t) & = (A(t)U(t) + F(t,U(t))) dt + B(t,U(t)) dW_H(t), \\quad t\\in [0,T], U(0) & = u_0. \\end{aligned}. \\end{equation} Here $(A(t))_{t\\in [0,T]}$ are unbounded operators with domains $(D(A(t)))_{t\\in [0,T]}$ which may be time dependent. We assume that $(A(t))_{t\\in [0,T]}$ satisfies the conditions of Acquistapace and Terreni. The functions $F$ and $B$ are nonlinear functions defined on certain interpolation spaces and $u_0\\in E$ is the initial value. $W_H$ is a cylindrical Brownian motion on a separable Hilbert space $H$. Under Lipschitz and linear growth conditions we show that there exists a unique mild solution of \\eqref{eq:SEab}. Under assumptions on the interpolation spaces we extend the factorization method of Da Prato, Kwapie\\'n, and Zabczyk, to obtain space-time regularity results for the solution $U$ of \\eqref{eq:SEab...

Veraar, Mark

2008-01-01T23:59:59.000Z

151

Bistability in the sine-Gordon equation: The ideal switch  

SciTech Connect

The sine-Gordon equation, used as the representative nonlinear wave equation, presents a bistable behavior resulting from nonlinearity and generating hysteresis properties. We show that the process can be understood in a comprehensive analytical formulation and that it is a generic property of nonlinear systems possessing a natural band gap. The approach allows one to discover that the sine-Gordon equation can work as an ideal switch by reaching a transmissive regime with vanishing driving amplitude.

Khomeriki, R. [Laboratoire de Physique Theorique et Astroparticules CNRS-UMR5207, Universite Montpellier 2, 34095 Montpellier (France); Physics Department, Tbilisi State University, 0128 Tbilisi (Georgia); Leon, J. [Laboratoire de Physique Theorique et Astroparticules CNRS-UMR5207, Universite Montpellier 2, 34095 Montpellier (France)

2005-05-01T23:59:59.000Z

152

A Quick Derivation of the Loop Equations for Random Matrices  

E-Print Network (OSTI)

The "loop equations" of random matrix theory are a hierarchy of equations born of attempts to obtain explicit formulae for generating functions of map enumeration problems. These equations, originating in the physics of 2-dimensional quantum gravity, have lacked mathematical justification. The goal of this paper is to provide a complete and short proof, relying on a recently established complete asymptotic expansion for the random matrix theory partition function.

N. M. Ercolani; K. D. T-R McLaughlin

2006-09-18T23:59:59.000Z

153

Power-law Spatial Dispersion from Fractional Liouville Equation  

E-Print Network (OSTI)

A microscopic model in the framework of fractional kinetics to describe spatial dispersion of power-law type is suggested. The Liouville equation with the Caputo fractional derivatives is used to obtain the power-law dependence of the absolute permittivity on the wave vector. The fractional differential equations for electrostatic potential in the media with power-law spatial dispersion are derived. The particular solutions of these equations for the electric potential of point charge in this media are considered.

Vasily E. Tarasov

2013-07-18T23:59:59.000Z

154

On the Fundamental Solution of a Homogeneous Linearized Coagulation Equation  

E-Print Network (OSTI)

In this paper we study the fundamental solution of the equation obtained by the linearisation of the Smoluchowski coagulation equation with the multiplicative kernel $(x y)^{\\lambda/2}$ with $\\lambda\\in (1, 2)$ around the steady state $f(x)=x^{-(3+\\lambda)/2}$. An explicit representation formula as well as detailed estimates on its asymptotics are obtained. We also describe in a detailed form particle fluxes between different sizes for this linearised equation.

M. Escobedo; J. J. L. Velazquez

2009-11-06T23:59:59.000Z

155

Description of collisionless plasmas by classical field equations  

SciTech Connect

Classical field equations are derived from quantum fields to obtain a different and possibly simpler description of a collisionless plasma. The method is to take the simultaneous limit, Dirac constant, e, m $Yields$ 0, of charged scalar fields and the electromagnetic field. Laplace transforms for perturbations in a uniform relativistic plasma are compared with corresponding results from the Maxwell--Vlasov equations. For the nonlinear case, a distribution function defined on the classical fields is shown to satisfy the Vlasov equation. (auth)

Fraley, G.S.

1975-10-01T23:59:59.000Z

156

A class of gauges for the Einstein equations  

E-Print Network (OSTI)

A class of gauges for the Einstein vacuum equations is introduced, along with three symmetric hyperbolic systems. The first implies the local realizability of the gauge. The second is the dynamical subset of the field equations. The third is used to show that the constraints propagate. The gauges are for an orthonormal frame formalism, with first order, quadratically nonlinear equations. The unknowns are 16 frame components and 28 connection components. After gauge-fixing, a total of 33 remain.

Michael Reiterer; Eugene Trubowitz

2011-04-26T23:59:59.000Z

157

An Equation for Moist Entropy in a Precipitating and Icy Atmosphere  

Science Conference Proceedings (OSTI)

This paper addresses an equation for moist entropy in the framework of cloud-resolving models. After rewriting the energy equation with moist entropy in the place of temperature, an equation for moist entropy is obtained. The equation expresses ...

Xiping Zeng; Wei-Kuo Tao; Joanne Simpson

2005-12-01T23:59:59.000Z

158

Stochastic point kinetics equations in nuclear reactor dynamics.  

E-Print Network (OSTI)

??A system of Itô stochastic differential equations is derived that model the dynamics of the neutron density and the delayed neutron precursors in a point… (more)

Hayes, James G.

2005-01-01T23:59:59.000Z

159

Interpretations of Space-Time Spectral Energy Equations  

Science Conference Proceedings (OSTI)

Interpretations are given of two different formulations of space-time spectral energy equations derived by Kao (1968) and Hayashi (1980).

Yoshikazu Hayashi

1982-03-01T23:59:59.000Z

160

A Rate Equation for the Nocturnal Boundary-Layer Height  

Science Conference Proceedings (OSTI)

A rate equation is derived which describes the development of the boundary-layer height under stable conditions as a function of time.

F. T. M. Nieuwstadt; H. Tennekes

1981-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

SCIENCE ON SATURDAY- "Disastrous Equations: The Role of Mathematics...  

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

On Saturday MBG Auditorium SCIENCE ON SATURDAY- "Disastrous Equations: The Role of Mathematics in Understanding Tsunami" Professor J. Douglas Wright, Associate Professor...

162

On Global Regularity of 2D Generalized Magnetohydrodynamic Equations  

E-Print Network (OSTI)

In this article we study the global regularity of 2D generalized magnetohydrodynamic equations (2D GMHD), in which the dissipation terms are $- \

Tran, Chuong V; Zhai, Zhichun

2013-01-01T23:59:59.000Z

163

Solution of a Linearized Model of Heisenberg's Fundamental Equation II  

E-Print Network (OSTI)

A linearized version of Heisenberg's fundamental equation is solved, and the solutions satisfy the axioms of a relativistic quantum field theory with a fundamental length.

E. Brüning; S. Nagamachi

2008-04-11T23:59:59.000Z

164

New renormalization group equations and the naturalness problem  

Science Conference Proceedings (OSTI)

Looking for an observable manifestation of the so-called unnaturalness of scalar fields, we introduce a seemingly new set of differential equations for connected Green functions. These equations describe the momentum dependence of the Green functions and are close relatives to the previously known renormalization group equations. Applying the new equations to the theory of scalar field with {phi}{sup 4} interaction, we identify a relation between the four-point Green function and the propagator that expresses the unnaturalness of the scalar field. Possible manifestations of the unnaturalness at low momenta are briefly discussed.

Pivovarov, Grigorii [Institute for Nuclear Research of Russian Academy of Sciences, 117312 Moscow (Russian Federation)

2010-04-01T23:59:59.000Z

165

Solution of Nonlinear Equations via Optimization [rev. 4  

E-Print Network (OSTI)

bound technique that can find all the solutions of nonlinear equation systems; Van Hentenryck, McAllester &. Kapur [28] who present a branch-and-prune ...

166

A Maxwell formulation for the equations of a plasma  

SciTech Connect

In light of the analogy between the structure of electrodynamics and fluid dynamics, the fluid equations of motion may be reformulated as a set of Maxwell equations. This analogy has been explored in the literature for incompressible turbulent flow and compressible flow but has not been widely explored in relation to plasmas. This letter introduces the analogous fluid Maxwell equations and formulates a set of Maxwell equations for a plasma in terms of the species canonical vorticity and its cross product with the species velocity. The form of the source terms is presented and the magnetohydrodynamic (MHD) limit restores the typical variety of MHD waves.

Thompson, Richard J.; Moeller, Trevor M. [Department of Mechanical, Aerospace and Biomedical Engineering, University of Tennessee Space Institute, Tullahoma, Tennessee 37388 (United States)

2012-01-15T23:59:59.000Z

167

Nonlocal Operators, Parabolic-type Equations, and Ultrametric Random Walks  

E-Print Network (OSTI)

In this article we introduce a new type of nonlocal operators and study the Cauchy problem for certain parabolic-type pseudodifferential equations naturally associated to these operators. Some of these equations are the p-adic master equations of certain models of complex systems introduced by Avetisov et al. The fundamental solutions of these parabolic-type equations are transition functions of random walks on the n-dimensional vector space over the field of p-adic numbers. We study some properties of these random walks, including the first passage time.

L. F. Chacón-Cortes; W. A. Zúńiga-Galindo

2013-08-22T23:59:59.000Z

168

New Renormalization Group Equations and the Naturalness Problem  

E-Print Network (OSTI)

Looking for an observable manifestation of the so-called unnaturalness of scalar fields we introduce a seemingly new set of differential equations for connected Green functions. These equations describe the momentum dependence of the Green functions and are close relatives to the previously known renormalization group equations. Applying the new equations to the theory of scalar field with $\\phi^4$ interaction we identify a relation between the four-point Green function and the propagator which expresses the unnaturalness of the scalar field. Possible manifestations of the unnaturalness at low momenta are briefly discussed.

Pivovarov, Grigorii

2010-01-01T23:59:59.000Z

169

Simplest Potential Conservation Laws of Linear Evolution Equations  

E-Print Network (OSTI)

Every simplest potential conservation law of any (1+1)-dimensional linear evolution equation of even order proves induced by a local conservation law of the same equation. This claim is true also for linear simplest potential conservation laws of (1+1)-dimensional linear evolution equations of odd order, which are related to linear potential systems. We also derive an effective criterion for checking whether a quadratic conservation law of a simplest linear potential system is a purely potential conservation law of a (1+1)-dimensional linear evolution equation of odd order.

Boyko, Vyacheslav M

2010-01-01T23:59:59.000Z

170

Universal equations and constants of turbulent motion  

E-Print Network (OSTI)

This paper presents a parameter-free theory of shear-generated turbulence at asymptotically high Reynolds numbers in incompressible fluids. It is based on a two-fluids concept. Both components are materially identical and inviscid. The first component is an ensemble of quasi-rigid dipole-vortex tubes as quasi-particles in chaotic motion. The second is a superfluid performing evasive motions between the tubes. The local dipole motions follow Helmholtz' law. The vortex radii scale with the energy-containing length scale. Collisions between quasi-particles lead either to annihilation (likewise rotation, turbulent dissipation) or to scattering (counterrotation, turbulent diffusion). There are analogies with birth and death processes of population dynamics and their master equations. For free homogeneous decay the theory predicts the TKE to follow 1/t. With an adiabatic condition at the wall it predicts the logarithmic law with von Karman's constant as 1/\\sqrt{2 pi} = 0.399. Likewise rotating couples form dissipative patches almost at rest ($\\rightarrow$ intermittency) wherein the spectrum evolves like an "Apollonian gear" as discussed first by Herrmann, 1990. On this basis the prefactor of the 3D-wavenumber spectrum is predicted as (1/3)(4 pi)^{2/3}=1.8; in the Lagrangian frequency spectrum it is simply 2. The results are situated well within the scatter range of observational, experimental and DNS results.

Helmut Z. Baumert

2012-03-22T23:59:59.000Z

171

Equations of state for hydrogen and deuterium.  

DOE Green Energy (OSTI)

This report describes the complete revision of a deuterium equation of state (EOS) model published in 1972. It uses the same general approach as the 1972 EOS, i.e., the so-called 'chemical model,' but incorporates a number of theoretical advances that have taken place during the past thirty years. Three phases are included: a molecular solid, an atomic solid, and a fluid phase consisting of both molecular and atomic species. Ionization and the insulator-metal transition are also included. The most important improvements are in the liquid perturbation theory, the treatment of molecular vibrations and rotations, and the ionization equilibrium and mixture models. In addition, new experimental data and theoretical calculations are used to calibrate certain model parameters, notably the zero-Kelvin isotherms for the molecular and atomic solids, and the quantum corrections to the liquid phase. The report gives a general overview of the model, followed by detailed discussions of the most important theoretical issues and extensive comparisons with the many experimental data that have been obtained during the last thirty years. Questions about the validity of the chemical model are also considered. Implications for modeling the 'giant planets' are also discussed.

Kerley, Gerald Irwin (Kerley Technical Services, Appomattox, VA)

2003-12-01T23:59:59.000Z

172

Complete Mie-Gruneisen Equation of State  

SciTech Connect

The Mie-Gruneisen equation of state (EOS) is frequently used in hydro simulations to model solids at high pressure (up to a few Mb). It is an incomplete EOS characterized by a Gruneisen coefficient, {Lambda} = -V({partial_derivative}{sub e}P){sub V}, that is a function of only V. Expressions are derived for isentropes and isotherms. This enables the extension to a complete EOS. Thermodynamic consistency requires that the specific heat is a function of a single scaled temperature. A complete extension is uniquely determined by the temperature dependence of the specific heat at a fixed reference density. In addition we show that if the domain of the EOS extends to T = 0 and the specific heat vanishes on the zero isotherm then {Lambda} a function of only V is equivalent to a specific heat with a single temperature scale. If the EOS domain does not include the zero isotherm, then a specific heat with a single temperature scale leads to a generalization of the Mie-Gruneisen EOS in which the pressure is linear in both the specific energy and the temperature. Such an EOS has previously been used to model liquid nitromethane.

Menikoff, Ralph [Los Alamos National Laboratory

2012-06-28T23:59:59.000Z

173

Scalar evolution equations for shear waves in incompressible solids: A simple derivation of the Z, ZK, KZK, and KP equations  

E-Print Network (OSTI)

We study the propagation of two-dimensional finite-amplitude shear waves in a nonlinear pre-strained incompressible solid, and derive several asymptotic amplitude equations in a simple, consistent, and rigorous manner. The scalar Zabolotskaya (Z) equation is shown to be the asymptotic limit of the equations of motion for all elastic generalized neo-Hookean solids (with strain energy depending only on the first principal invariant of Cauchy-Green strain). However, we show that the Z equation cannot be a scalar equation for the propagation of two-dimensional shear waves in general elastic materials (with strain energy depending on the first and second principal invariants of strain). Then we introduce dispersive and dissipative terms to deduce the scalar Kadomtsev-Petviashvili (KP), Zabolotskaya-Khokhlov (ZK) and Khokhlov-Zabolotskaya-Kuznetsov (KZK) equations of incompressible solid mechanics.

Michel Destrade; Alain Goriely; Giuseppe Saccomandi

2013-02-01T23:59:59.000Z

174

A Cartesian Grid Embedded Boundary Method for the Heat Equation and Poisson's  

E-Print Network (OSTI)

A Cartesian Grid Embedded Boundary Method for the Heat Equation and Poisson's Equation in Three's equation, and second-order accurate in space and time for the heat equation. Cartesian grid methods present an algorithm for solving Poisson's equation and the heat equation on irregular domains in three

175

Numerical Regularized Moment Method of Arbitrary Order for Boltzmann-BGK Equation  

Science Conference Proceedings (OSTI)

We introduce a numerical method for solving Grad's moment equations or regularized moment equations for an arbitrary order of moments. In our algorithm, we do not explicitly need the moment equations. Instead, we directly start from the Boltzmann equation ... Keywords: Boltzmann-BGK equation, Grad's moment method, regularized moment-equations

Zhenning Cai; Ruo Li

2010-08-01T23:59:59.000Z

176

DISCRETE SYMMETRIES OF THE BLACK-SCHOLES EQUATION  

E-Print Network (OSTI)

DISCRETE SYMMETRIES OF THE BLACK-SCHOLES EQUATION Gheorghe Silberberg Abstract The paper computes the full automorphism group of the Lie al- gebra associated to the Black-Scholes equation and determines symmetries. The present paper applies the whole procedure to the famous Black- Scholes partial differential

177

MIB method for elliptic equations with multi-material interfaces  

Science Conference Proceedings (OSTI)

Elliptic partial differential equations (PDEs) are widely used to model real-world problems. Due to the heterogeneous characteristics of many naturally occurring materials and man-made structures, devices, and equipments, one frequently needs to solve ... Keywords: Elliptic equations, Ghost fluid method, Immersed boundary method, Immersed interface method, Matched interface and boundary, Multiple material interfaces, Triple-junctions

Kelin Xia; Meng Zhan; Guo-Wei Wei

2011-06-01T23:59:59.000Z

178

A uniformly second order fast sweeping method for eikonal equations  

Science Conference Proceedings (OSTI)

A uniformly second order method with a local solver based on the piecewise linear discontinuous Galerkin formulation is introduced to solve the eikonal equation with Dirichlet boundary conditions. The method utilizes an interesting phenomenon, referred ... Keywords: Discontinuous Galerkin method, Eikonal equations, Fast sweeping method, Superconvergence, Uniformly second order

Songting Luo

2013-05-01T23:59:59.000Z

179

A Taylor polynomial approach for solving differential-difference equations  

Science Conference Proceedings (OSTI)

The purpose of this study is to give a Taylor polynomial approximation for the solution of mth-order linear differential-difference equations with variable coefficients under the mixed conditions about any point. For this purpose, Taylor matrix method ... Keywords: 39A10, 41A10, 65Q05, Differential-difference equations, Taylor matrix method, Taylor polynomial solutions, Taylor polynomials and series

Mustafa Gülsu; Mehmet Sezer

2006-02-01T23:59:59.000Z

180

Mixed-hybrid discretization methods for the P1 equations  

Science Conference Proceedings (OSTI)

We consider mixed-hybrid discretization methods for the linear Boltzmann transport equation which is extensively used in computational neutron transport. Mixed-hybrid methods combine attractive features of both mixed and hybrid methods, namely the simultaneous ... Keywords: 02.60.Cb, 02.70.Dh, 65N12, 65N30, Linear Boltzmann transport equation, Mixed-hybrid discretization methods, P1 approximation

S. Van Criekingen; R. Beauwens

2007-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

A constitutive equation for ceramic materials used in lightweight armors  

Science Conference Proceedings (OSTI)

A constitutive model to simulate the behavior of ceramic materials under impact loading is proposed in order to achieve a better representation of the damage process due to the material fragmentation. To integrate the proposed constitutive equations, ... Keywords: Armor, Ceramic, Constitutive equation, Damage, Impact, Return mapping algorithm

D. Fernández-Fdz; R. Zaera; J. Fernández-Sáez

2011-12-01T23:59:59.000Z

182

Regularity results for the Primitive Equations of the ocean  

E-Print Network (OSTI)

We consider the linear Primitive Equations of the ocean in the three dimensional space, with horizontal periodic and vertical Dirichlet boundary conditions. Thanks to Fourier transforms we are able to calculate explicitly the pressure term. We then state existence, unicity and regularity results for the linear time-depending Primitive Equations, with low-regularity right-hand side.

Nodet, Maëlle

2008-01-01T23:59:59.000Z

183

Regularity results for the Primitive Equations of the ocean  

E-Print Network (OSTI)

We consider the linear Primitive Equations of the ocean in the three dimensional space, with horizontal periodic and vertical Dirichlet boundary conditions. Thanks to Fourier transforms we are able to calculate explicitly the pressure term. We then state existence, unicity and regularity results for the linear time-depending Primitive Equations, with low-regularity right-hand side.

Maëlle Nodet

2008-04-06T23:59:59.000Z

184

A modified boundary integral evolution formulation for the wave equation  

Science Conference Proceedings (OSTI)

We apply a modified boundary integral formulation otherwise known as the Green element method (GEM) to the solution of the two-dimensional scalar wave equation. GEM essentially combines three techniques namely: (a) finite difference approximation of ... Keywords: Boundary element method, Green element method, Overhauser elements, Wave equation

Okey Oseloka Onyejekwe

2009-07-01T23:59:59.000Z

185

Exact null controllability of degenerate evolution equations with scalar control  

SciTech Connect

Necessary and sufficient conditions for the exact null controllability of a degenerate linear evolution equation with scalar control are obtained. These general results are used to examine the exact null controllability of the Dzektser equation in the theory of seepage. Bibliography: 13 titles.

Fedorov, Vladimir E; Shklyar, Benzion

2012-12-31T23:59:59.000Z

186

A Lyapunov approach to the stability of fractional differential equations  

Science Conference Proceedings (OSTI)

Lyapunov stability of fractional differential equations is addressed in this paper. The key concept is the frequency distributed fractional integrator model, which is the basis for a global state space model of FDEs. Two approaches are presented: the ... Keywords: Fractional differential equations, Fractional integrator, Lyapunov stability, Nonlinear FDEs, State space models

J. C. Trigeassou; N. Maamri; J. Sabatier; A. Oustaloup

2011-03-01T23:59:59.000Z

187

Solving Systems of Linear Equations with Relaxed Monte Carlo Method  

Science Conference Proceedings (OSTI)

The problem of solving systems of linear algebraic equations by parallel Monte Carlo numerical methods is considered. A parallel Monte Carlo method with relaxation is presented. This is a report of a research in progress, showing the effectiveness of ... Keywords: Monte Carlo method, linear solver, parallel algorithms, systems of linear algebraic equations

Chih Jeng Kenneth Tan

2002-05-01T23:59:59.000Z

188

Nonhomogeneos Boundary-Value Problem for Semilinear Hyperbolic Equation. Stability  

Science Conference Proceedings (OSTI)

We discuss the solvability of the nonhomogeneous boundary-value problem for the semilinear equation of the vibrating string x tt (t, ... Keywords: 35L20, Primary 35L05, Secondary 58J45, Wave equations, nonconvex duality, variational method, weak solutions

Andrzej Nowakowski

2008-10-01T23:59:59.000Z

189

Joint mixed logit models of stated and revealed preferences for alternative-fuel vehicles  

E-Print Network (OSTI)

sports car Constant for CNG Constant for methanol Std. dev.Gasoline Std. dev. EV Std. dev. CNG Std. dev. methanol Std.wagon Constant for EV Constant for CNG Constant for methanol

Brownstone, David; Bunch, David S; Train, Kenneth

1999-01-01T23:59:59.000Z

190

Joint mixed logit models of stated and revealed preferences for alternative-fuel vehicles  

E-Print Network (OSTI)

EV Electric truck Electric sports car Constant for CNGmethanol Electric truck Electric sports car College ´ EV SPEV Electric truck Electric sports car Constant for CNG

Brownstone, David; Bunch, David S; Train, Kenneth

1999-01-01T23:59:59.000Z

191

Residential mobility and location choice: a nested logit model with sampling of alternatives  

E-Print Network (OSTI)

Waddell, P. : Modeling residential location in UrbanSim. In:D. (eds. ) Modelling Residential Location Choice. Springer,based model system and a residential location model. Urban

Lee, Brian H.; Waddell, Paul

2010-01-01T23:59:59.000Z

192

PRISM 2.0: Mixed Logit Consumer Vehicle Choice Modeling Using Revealed Preference Data  

Science Conference Proceedings (OSTI)

Predicting the penetration of electric vehicles into the automotive market is challenging because these vehicles do not exist in the market today and therefore consumer reaction is largely unknown. One way to estimate consumer demand for electric vehicles is to model the attribute bundles of vehicles that are present in the market today and predict market share using state-of-the-art discrete choice demand models.This research develops a choice-based demand model to extract consumer ...

2013-09-30T23:59:59.000Z

193

A logit model for predicting wetland location using ASTER and GIS  

Science Conference Proceedings (OSTI)

Data from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) were used to develop a logistic regression model to predict the location of wetlands in the Coastal Plain of Virginia. We used the first five bands from two ASTER scenes ...

E. Pantaleoni; R. H. Wynne; J. M. Galbraith; J. B. Campbell

2009-01-01T23:59:59.000Z

194

Joint mixed logit models of stated and revealed preferences for alternative-fuel vehicles  

E-Print Network (OSTI)

electric, methanol, and compressed natural gas vehicles withinclude electric, compressed natural gas (CNG), and methanoltypes: gasoline, compressed natural gas (CNG), methanol, and

Brownstone, David; Bunch, David S; Train, Kenneth

1999-01-01T23:59:59.000Z

195

Electrolux Gibson Air Conditioner and Equator Clothes Washer Fail DOE  

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

Electrolux Gibson Air Conditioner and Equator Clothes Washer Fail Electrolux Gibson Air Conditioner and Equator Clothes Washer Fail DOE Energy Star Testing Electrolux Gibson Air Conditioner and Equator Clothes Washer Fail DOE Energy Star Testing October 6, 2010 - 10:08am Addthis DOE testing in support of the ENERGY STAR program has revealed that an Electrolux Gibson air conditioner (model GAH105Q2T1) and an Equator clothes washer (model EZ 3720 CEE), both of which claimed ENERGY STAR ratings, do not meet the ENERGY STAR requirements. Specifically, the test results for the Electrolux Gibson model show that, when tested in accordance with DOE's test procedures, it consumed 6.1 percent more energy than the Energy Star requirement. Test results for the Equator model show that it exceeds Energy Star's water factor requirements by 12.3 percent.

196

Nonlinear thermodynamic quantum master equation: Properties and examples  

Science Conference Proceedings (OSTI)

The quantum master equation obtained from two different thermodynamic arguments is seriously nonlinear. We argue that, for quantum systems, nonlinearity occurs naturally in the step from reversible to irreversible equations and we analyze the nature and consequences of the nonlinear contribution. The thermodynamic nonlinearity naturally leads to canonical equilibrium solutions and extends the range of validity to lower temperatures. We discuss the Markovian character of the thermodynamic quantum master equation and introduce a solution strategy based on coupled evolution equations for the eigenstates and eigenvalues of the density matrix. The general ideas are illustrated for the two-level system and for the damped harmonic oscillator. Several conceptual implications of the nonlinearity of the thermodynamic quantum master equation are pointed out, including the absence of a Heisenberg picture and the resulting difficulties with defining multitime correlations.

Oettinger, Hans Christian [ETH Zuerich, Department of Materials, Polymer Physics, HCI H 543, CH-8093 Zuerich (Switzerland)

2010-11-15T23:59:59.000Z

197

Nonlinear stability analysis of the Emden-Fowler equation  

E-Print Network (OSTI)

In this paper we qualitatively study radial solutions of the semilinear elliptic equation $\\Delta u + u^n = 0$ with $u(0)=1$ and $u'(0)=0$ on the positive real line, called the Emden-Fowler or Lane-Emden equation. This equation is of great importance in Newtonian astrophysics and the constant $n$ is called the polytropic index. By introducing a set of new variables, the Emden-Fowler equation can be written as an autonomous system of two ordinary differential equations which can be analyzed using linear and nonlinear stability analysis. We perform the study of stability by using linear stability analysis, the Jacobi stability analysis (Kosambi-Cartan-Chern theory) and the Lyapunov function method. Depending on the values of $n$ these different methods yield different results. We identify a parameter range for $n$ where all three methods imply stability.

Christian G. Boehmer; Tiberiu Harko

2009-02-06T23:59:59.000Z

198

Electrolux Gibson Air Conditioner and Equator Clothes Washer Fail DOE  

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

Electrolux Gibson Air Conditioner and Equator Clothes Washer Fail Electrolux Gibson Air Conditioner and Equator Clothes Washer Fail DOE Energy Star Testing Electrolux Gibson Air Conditioner and Equator Clothes Washer Fail DOE Energy Star Testing October 6, 2010 - 10:08am Addthis DOE testing in support of the ENERGY STAR program has revealed that an Electrolux Gibson air conditioner (model GAH105Q2T1) and an Equator clothes washer (model EZ 3720 CEE), both of which claimed ENERGY STAR ratings, do not meet the ENERGY STAR requirements. Specifically, the test results for the Electrolux Gibson model show that, when tested in accordance with DOE's test procedures, it consumed 6.1 percent more energy than the Energy Star requirement. Test results for the Equator model show that it exceeds Energy Star's water factor requirements by 12.3 percent.

199

Changing the Equation in STEM Education | Department of Energy  

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

Equation in STEM Education Equation in STEM Education Changing the Equation in STEM Education September 20, 2010 - 11:34am Addthis Katelyn Sabochik Editor's Note: This is a cross post of an announcement that the White House featured on its blog last week. Check out the video below for Secretary Chu's thoughts on how an education in math and science helps students understand the world and deal with the pressing issues of our time. Today, President Obama announced the launch of Change the Equation, a CEO-led effort to dramatically improve education in science, technology, engineering, and math (STEM), as part of his "Educate to Innovate" campaign. Change the Equation is a non-profit organization dedicated to mobilizing the business community to improve the quality of STEM education

200

An Efficient Hybrid Parabolic Equation --- Integral Equation Method for the Analysis of Wave Propagation in Highly Complex Indoor Communication Environments  

Science Conference Proceedings (OSTI)

An efficient, full-wave computational technique to investigate the electromagnetic wave propagation within a complex building environment, resulting from contemporary indoor communication systems, is proposed. Unlike a standard ray-tracing technique, ... Keywords: indoor communications, integral equations, parabolic equation, ray-tracing, wave propagation

G. K. Theofilogiannakos; T. V. Yioultsis; T. D. Xenos

2007-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

Conservation Laws and Potential Symmetries of Linear Parabolic Equations  

E-Print Network (OSTI)

We carry out an extensive investigation of conservation laws and potential symmetries for the class of linear (1+1)-dimensional second-order parabolic equations. The group classification of this class is revised by employing admissible transformations, the notion of normalized classes of differential equations and the adjoint variational principle. All possible potential conservation laws are described completely. They are in fact exhausted by local conservation laws. For any equation from the above class the characteristic space of local conservation laws is isomorphic to the solution set of the adjoint equation. Effective criteria for the existence of potential symmetries are proposed. Their proofs involve a rather intricate interplay between different representations of potential systems, the notion of a potential equation associated with a tuple of characteristics, prolongation of the equivalence group to the whole potential frame and application of multiple dual Darboux transformations. Based on the tools developed, a preliminary analysis of generalized potential symmetries is carried out and then applied to substantiate our construction of potential systems. The simplest potential symmetries of the linear heat equation, which are associated with single conservation laws, are classified with respect to its point symmetry group. Equations possessing infinite series of potential symmetry algebras are studied in detail.

Roman O. Popovych; Michael Kunzinger; Nataliya M. Ivanova

2007-06-04T23:59:59.000Z

202

Probing the softest region of the nuclear equation of state  

E-Print Network (OSTI)

An attractive, energy-dependent mean-field potential for baryons is introduced in order to generate a soft region in the nuclear equation of state, as suggested by recent lattice QCD calculations of baryon-free matter at finite temperature. Based on a hadronic transport model, we find that although this equation of state has negligible effects on the inclusive hadronic spectra, it leads to a minimum in the energy dependence of the transverse collective flow and a delayed expansion of the compressed matter. In particular, the transverse flow changes its direction as the colliding system passes through the softest region in the equation of state.

Li, Ba; Ko, Che Ming.

1998-01-01T23:59:59.000Z

203

Improved phenomenological equation of state in the chemical picture  

E-Print Network (OSTI)

I present an overview of an equation of state, being developed in the chemical picture, and based on the very successful MHD equation of state. The flexibility of the chemical picture combined with the free-energy minimization procedure, makes it rather straight-forward, albeit laborious, to include new effects in the model free-energy, simply by adding new terms. The most notable additions to the original MHD equation of state, are relativistic effects, quantum effects, improved higher order Coulomb terms and a long list of molecules other than the H2 and H2+ treated so far.

Regner Trampedach

2004-11-12T23:59:59.000Z

204

Harmonic coordinates in the string and membrane equations  

Science Conference Proceedings (OSTI)

In this note, we first show that the solutions to Cauchy problems for two versions of relativistic string and membrane equations are diffeomorphic. Then we investigate the coordinates transformation presented in D. X. Kong and Q. Zhang [Physica D 238, 902 (2009); see (2.20)] which plays an important role in the study on the dynamics of the motion of string in Minkowski space. This kind of transformed coordinates is harmonic coordinates, and the nonlinear relativistic string equations can be straightforwardly simplified into linear wave equations under this transformation.

He Chunlei; Huang Shoujun [Department of Mathematics, Anhui Normal University, Wuhu 241000 (China)

2010-09-15T23:59:59.000Z

205

Hamiltonian form and solitary waves of the spatial Dysthe equations  

E-Print Network (OSTI)

The spatial Dysthe equations describe the envelope evolution of the free-surface and potential of gravity waves in deep waters. Their Hamiltonian structure and new invariants are unveiled by means of a gauge transformation to a new canonical form of the evolution equations. An accurate Fourier-type spectral scheme is used to solve for the wave dynamics and validate the new conservation laws, which are satisfied up to machine precision. Traveling waves are numerically constructed using the Petviashvili method. It is shown that their collision appears inelastic, suggesting the non-integrability of the Dysthe equations.

Fedele, Francesco

2011-01-01T23:59:59.000Z

206

Quasi-Lie schemes and Emden--Fowler equations  

E-Print Network (OSTI)

The recently developed theory of quasi-Lie schemes is studied and applied to investigate several equations of Emden type and a scheme to deal with them and some of their generalisations is given. As a first result we obtain t-dependent constants of the motion for particular instances of Emden equations by means of some of their particular solutions. Previously known results are recovered from this new perspective. Finally some t-dependent constants of the motion for equations of Emden type satisfying certain conditions are recovered.

J. F. Carińena; P. G. L. Leach; J. de Lucas

2009-08-16T23:59:59.000Z

207

Role of retardation in 3-D relativistic equations  

E-Print Network (OSTI)

Equal-time Green's function is used to derive a three-dimensional integral equation from the Bethe-Salpeter equation. The resultant equation, in the absence of anti-particles, is identical to the use of time-ordered diagrams, and has been used within the framework of $\\phi^2\\sigma$ coupling to study the role of energy dependence and non-locality when the two-body potential is the sum of $\\sigma$-exchange and crossed $\\sigma$ exchange. The results show that non-locality and energy dependence make a substantial contribution to both the on-shell and off-shell amplitudes.

A. D. Lahiff; I. R. Afnan

1997-08-20T23:59:59.000Z

208

Photonic equation of motion with application to the Lamb shift  

DOE Green Energy (OSTI)

A photonic equation of motion is proposed which is the scalar product of four-vectors and therefore a Lorentz invariant. A photonic equation of motion, which has not been heretofore established in quantum electrodynamics (QED), would capture the quantum nature of light but yet not have the standard field-operator form, thereby making practical calculations easier to perform. The equation of motion proposed here is applied to the Lamb shift. No divergences exist, and the result agrees with the observed Lamb shift for the 1S{sub 1/2} state of hydrogen within experimental error.

Ritchie, A B

2006-12-21T23:59:59.000Z

209

Convective Interaction with Dynamics in a Linear Primitive Equation Model  

Science Conference Proceedings (OSTI)

A new global atmosphere model purpose designed for climate studies is introduced. The model is solved in terms of the normal modes of the linearized primitive equations on a sphere, which allows use of long time steps without introducing ...

Richard Seager; Stephen E. Zebiak

1994-05-01T23:59:59.000Z

210

Modeling Supercritical Systems With Tough2- The Eoslsc Equation...  

Open Energy Info (EERE)

| Sign Up Search Page Edit with form History Facebook icon Twitter icon Modeling Supercritical Systems With Tough2- The Eoslsc Equation Of State Module And A Basin And Range...

211

Parameter Sensitivity of Primitive Equation Ocean General Circulation Models  

Science Conference Proceedings (OSTI)

Experiments with a low resolution, primitive equation ocean general circulation model with idealized basin geometry and surface forcing have been carried out in order to identify the processes controlling the climatically important aspects of the ...

Frank Bryan

1987-07-01T23:59:59.000Z

212

Towards multiscale simulation of moist flows with soundproof equations  

Science Conference Proceedings (OSTI)

This paper discusses incorporation of phase changes of the water substance that accompany moist atmospheric flows into the all-scale atmospheric model based on soundproof equations. Specific issue concerns developing a theoretical basis and ...

Marcin J. Kurowski; Wojciech W. Grabowski; Piotr K. Smolarkiewicz

213

A Simplified System of Equations for Simulation of Tropical Cyclones  

Science Conference Proceedings (OSTI)

A simplified system of equations which can simulate the development and mature stages of tropical cyclones is presented. The model is similar to that presented by Ooyama, except that the assumption of incompressible fluid layers is relaxed. ...

Mark DeMaria; John D. Pickle

1988-05-01T23:59:59.000Z

214

Direct Elliptic Equation Solvers with Low Memory Requirements  

Science Conference Proceedings (OSTI)

Several simple modifications of the Lindzen-Kuo Gaussian elimination algorithm for solving elliptic differential equations are derived. These modifications greatly decrease the auxiliary memory requirements with only some increase in computation, ...

Mark R. Schoeberl

1980-09-01T23:59:59.000Z

215

An Extremum Solution of the Monin–Obukhov Similarity Equations  

Science Conference Proceedings (OSTI)

An extremum hypothesis of turbulent transport in the atmospheric surface layer is postulated. The hypothesis has led to a unique solution of Monin–Obukhov similarity equations in terms of simple expressions linking shear stress (momentum flux) ...

Jingfeng Wang; Rafael L. Bras

2010-02-01T23:59:59.000Z

216

An Alternative Leapfrog Scheme for Surface Gravity Wave Equations  

Science Conference Proceedings (OSTI)

An alternative leapfrog scheme using a staggered time grid system is proposed to solve surface gravity wave equations. In addition to the nondissipative second-order accuracy scheme that is inherent in the standard leapfrog scheme, the ...

Weidong Zhou

2002-09-01T23:59:59.000Z

217

Exact Vacuum Solutions of Jordan, Brans-Dicke Field Equations  

E-Print Network (OSTI)

We present the static spherically symmetric vacuum solutions of the Jordan, Brans-Dicke field equations. The new solutions are obtained by considering a polar Gaussian, isothermal and radial hyperbolic metrics.

Sergey Kozyrev

2005-12-04T23:59:59.000Z

218

Why the ITCZ Is Mostly North of the Equator  

Science Conference Proceedings (OSTI)

Although the distribution of sunshine is symmetrical about the equator, the earth's climate is not. Climatic asymmetries are prominent in the eastern tropical Pacific and Atlantic Oceans where the regions of maximum sea surface temperature, ...

S. G. H. Philander; D. Gu; G. Lambert; T. Li; D. Halpern; N-C. Lau; R. C. Pacanowski

1996-12-01T23:59:59.000Z

219

Bunches of differential forms and the Einstein equation  

SciTech Connect

A technique is developed for investigating the vacuum Einstein equation by the use of bunches of differential forms. A connection is established between this method and the twistors of Penrose and the wrench functions of Plebanski.

Gindikin, S.G.

1982-08-01T23:59:59.000Z

220

On the Deformation Term in the Quasigeostrophic Omega Equation  

Science Conference Proceedings (OSTI)

It is a common diagnostic, synoptic practice to consider the Trenberth–Sutcliffe approximation to the quasigeostrophic (QG) omega equation, which relates upward vertical motion to regions of cyclonic vorticity advection by the thermal wind. Use ...

Jonathan E. Martin

1998-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

Parabolic Equations and Markov Processes Over p-adic Fields  

E-Print Network (OSTI)

We construct and study a fundamental solution of Cauchy's problem for p-adic parabolic equations of a certain the type. The fundamental solution is the transition density of a p-adic Markov process.

W. A. Zuniga-Galindo

2006-12-11T23:59:59.000Z

222

The Hydrostatic Equation in the Evaluation Algorithm for Radiosonde Data  

Science Conference Proceedings (OSTI)

In upper-air observations, height data are normally computed from pressure and virtual temperature by resort of the hydrostatic equation. Errors in the primary variables affect the accuracy of height data depending on how the integration of the ...

Hans Richner; Pierre Viatte

1995-06-01T23:59:59.000Z

223

Gravitation and Thermodynamics: The Einstein Equation of State Revisited  

E-Print Network (OSTI)

We perform an analysis where Einstein's field equation is derived by means of very simple thermodynamical arguments. Our derivation is based on a consideration of the properties of a very small, spacelike two-plane in a uniformly accelerating motion.

Jarmo Makela; Ari Peltola

2006-12-13T23:59:59.000Z

224

High accuracy periodic solutions to the Sivashinsky equation  

Science Conference Proceedings (OSTI)

The aim of this work is the accurate calculation of periodic solutions to the Sivashinsky equation, which models dynamics of the long wave instability of laminar premixed flame. A highly accurate computational algorithm was developed in both one and ...

V. Karlin; V. Maz'ya; G. Schmidt

2003-06-01T23:59:59.000Z

225

Constitutive equations for meeting elevated-temperature-design needs  

SciTech Connect

Constitutive equations for representing the inelastic behavior of structural alloys at temperatures in the creep regime are discussed from the viewpoint of advances made over the past decade. An emphasis is placed on the progress that has been made in meeting the needs of the program whose design process is based in part on a design-by-inelastic-analysis approach. In particular, the constitutive equations that have been put into place for current use in design analyses are discussed along with some material behavior background information. Equations representing short-term plastic and long-term creep behaviors are considered. Trends towards establishing improved equations for use in the future are also described. Progress relating to fundamentals of continuum mechanics, physical modeling, phenomenological modeling, and implementation is addressed.

Pugh, C.E.; Robinson, D.N.

1981-01-01T23:59:59.000Z

226

The Scaling Group of the Radiative Transfer Equation  

Science Conference Proceedings (OSTI)

We show that the equation of radiative transfer is invariant under a group of simultaneous transformations of the scale (i.e., the optical thickness) and the phase function. In this way, we provide a unified explanation of various empirical ...

Bruce H. J. McKellar; Michael A. Box

1981-05-01T23:59:59.000Z

227

The Lorentz Condition is Equivalent to Maxwell Equations  

E-Print Network (OSTI)

It is shown that the Lorentz condition which is a conservation law on the electromagnetic four-vector-density A, plus the Lorentz transformation, taken together, are equivalent to the microscopic Maxwell's equations.

Edmund A. Di Marzio

2008-11-26T23:59:59.000Z

228

The Buoyancy Budget with a Nonlinear Equation of State  

Science Conference Proceedings (OSTI)

The nonlinear equation of state of seawater introduces a sink or source of buoyancy when water parcels of unequal salinities and temperatures are mixed. This article contains quantitative estimates of these nonlinear effects on the buoyancy budget ...

Magnus Hieronymus; Jonas Nycander

2013-01-01T23:59:59.000Z

229

Multidomain spectral method for the helically reduced wave equation  

Science Conference Proceedings (OSTI)

We consider the 2+1 and 3+1 scalar wave equations reduced via a helical Killing field, respectively referred to as the 2-dimensional and 3-dimensional helically reduced wave equation (HRWE). The HRWE serves as the fundamental model for the mixed-type ... Keywords: 35L05, 35M10, 5L20, 65M70, 83C35, Gravitational waves, Helical symmetry, Mixed PDE, Spectral methods

Stephen R. Lau; Richard H. Price

2007-12-01T23:59:59.000Z

230

International Conference on Multiscale Methods and Partial Differential Equations.  

SciTech Connect

The International Conference on Multiscale Methods and Partial Differential Equations (ICMMPDE for short) was held at IPAM, UCLA on August 26-27, 2005. The conference brought together researchers, students and practitioners with interest in the theoretical, computational and practical aspects of multiscale problems and related partial differential equations. The conference provided a forum to exchange and stimulate new ideas from different disciplines, and to formulate new challenging multiscale problems that will have impact in applications.

Thomas Hou

2006-12-12T23:59:59.000Z

231

Reflection-Transmission Quantum Yang-Baxter Equations  

E-Print Network (OSTI)

We explore the reflection-transmission quantum Yang-Baxter equations, arising in factorized scattering theory of integrable models with impurities. The physical origin of these equations is clarified and three general families of solutions are described in detail. Explicit representatives of each family are also displayed. These results allow to establish a direct relationship with the different previous works on the subject and make evident the advantages of the reflection-transmission algebra as an universal approach to integrable systems with impurities.

V. Caudrelier; M. Mintchev; E. Ragoucy; P. Sorba

2004-12-15T23:59:59.000Z

232

Mpemba effect, Newton cooling law and heat transfer equation  

E-Print Network (OSTI)

In this work we suggest a simple theoretical solution of the Mpemba effect in full agreement with known experimental data. This solution follows simply as an especial approximation (linearization) of the usual heat (transfer) equation, precisely linearization of the second derivation of the space part of the temperature function (as it is well-known Newton cooling law can be considered as the effective approximation of the heat (transfer) equation for constant space part of the temperature function).

Vladan Pankovic; Darko V. Kapor

2010-05-06T23:59:59.000Z

233

General Solutions to Static Plane Symmetric Einstein's Equations  

E-Print Network (OSTI)

A general formula for the metric as an explicit function of the generic energy-momentum tensor is given which satisfies static plane symmetric Einstein's equations with cosmological constant.In order to illustrate it, the solutions for the vacuum with cosmological constant, the perfect fluid with a linear equation of state and the electrically charged plane are derived and compared with known results. The general solution with a linear relation among the energy-momentum tensor components is also obtained.

Leandro G. Gomes

2013-08-23T23:59:59.000Z

234

Quantum theory of rotational isomerism and Hill equation  

SciTech Connect

The process of rotational isomerism of linear triatomic molecules is described by the potential with two different-depth minima and one barrier between them. The corresponding quantum-mechanical equation is represented in the form that is a special case of the Hill equation. It is shown that the Hill-Schroedinger equation has a Klein's quadratic group symmetry which, in its turn, contains three invariant subgroups. The presence of these subgroups makes it possible to create a picture of energy spectrum which depends on a parameter and has many merging and branch points. The parameter-dependent energy spectrum of the Hill-Schroedinger equation, like Mathieu-characteristics, contains branch points from the left and from the right of the demarcation line. However, compared to the Mathieu-characteristics, in the Hill-Schroedinger equation spectrum the 'right' points are moved away even further for some distance that is the bigger, the bigger is the less deep well. The asymptotic wave functions of the Hill-Schroedinger equation for the energy values near the potential minimum contain two isolated sharp peaks indicating a possibility of the presence of two stable isomers. At high energy values near the potential maximum, the height of two peaks decreases, and between them there appear chaotic oscillations. This form of the wave functions corresponds to the process of isomerization.

Ugulava, A.; Toklikishvili, Z.; Chkhaidze, S.; Abramishvili, R. [I. Javakhishvili Tbilisi State University, 3, I. Chavchavadze Avenue, 0179 Tbilisi (Georgia); Chotorlishvili, L. [Institut fuer Physik, Martin-Luther Universitat Halle-Wittenberg, Heinrich-Damerow-Str. 4, 06120 Halle (Germany)

2012-06-15T23:59:59.000Z

235

Approximate Controllability for Linear Stochastic Differential Equations in Infinite Dimensions  

SciTech Connect

The objective of the paper is to investigate the approximate controllability property of a linear stochastic control system with values in a separable real Hilbert space. In a first step we prove the existence and uniqueness for the solution of the dual linear backward stochastic differential equation. This equation has the particularity that in addition to an unbounded operator acting on the Y-component of the solution there is still another one acting on the Z-component. With the help of this dual equation we then deduce the duality between approximate controllability and observability. Finally, under the assumption that the unbounded operator acting on the state process of the forward equation is an infinitesimal generator of an exponentially stable semigroup, we show that the generalized Hautus test provides a necessary condition for the approximate controllability. The paper generalizes former results by Buckdahn, Quincampoix and Tessitore (Stochastic Partial Differential Equations and Applications, Series of Lecture Notes in Pure and Appl. Math., vol. 245, pp. 253-260, Chapman and Hall, London, 2006) and Goreac (Applied Analysis and Differential Equations, pp. 153-164, World Scientific, Singapore, 2007) from the finite dimensional to the infinite dimensional case.

Goreac, D. [Universite Paris-Est, LAMA, UMR 8050 (France)], E-mail: dan.goreac@univ-mlv.fr

2009-08-15T23:59:59.000Z

236

Retrieval of Thermodynamic Fields from Multiple-Doppler Radar Data Using the Equations of Motion and the Thermodynamic Equation  

Science Conference Proceedings (OSTI)

A new method is proposed to determine completely the thermodynamic fields from the relative pressure and temperature perturbations, retrieved from the processing of multiple-Doppler radar data through the equations of motion. A simplified ...

Frank Roux

1985-12-01T23:59:59.000Z

237

Application of the Spectral Method to Solve the Meridional Circulation Equation in Spherical-Sigma Coordinates  

Science Conference Proceedings (OSTI)

The equation governing the zonally averaged meridional circulation (W?, v? in spherical-sigma coordinates is formulated including the semigeostrophic terms. This equation and the mass continuity equation are spectrally transformed in terms of ...

H-I. Lu; R. L. Pfeffer

1985-11-01T23:59:59.000Z

238

A Comparison of Primitive and Balance Equation Simulations of Baroclinic Waves  

Science Conference Proceedings (OSTI)

The balance equations are an approximate set of equations that reduce to gradient wind balance under steady, circular flow conditions on an f plane. Scale analysis indicates that these equations are potentially quite accurate over a wide variety ...

Jeffrey S. Whitaker

1993-06-01T23:59:59.000Z

239

A Rate Equation for the Inversion Height in a Nocturnal Boundary Layer  

Science Conference Proceedings (OSTI)

The application of a self-similar profile in the integration of the temperature equation across the stable boundary layer leads to a rate equation for the inversion height. An analytic solution of the resulting equation is derived. Its behavior ...

F. T. M. Nieuwstadt

1980-12-01T23:59:59.000Z

240

Nonlinear Klein-Gordon equation fot nanoscale heat and mass transport  

E-Print Network (OSTI)

In this paper nonlinear Klein-Gordon equation for heat and mass transport in nanoscale was proposed and solved. It was shown that for ultra-short laser pulses nonlinear Klein-Gordon equation is reduced to nonlinear d`Alembert equation. The implicit solution of the d`Alembert equation for ultrashort laser pulses was obtained Key words: nonlinear Klein-Gordon equation, d`Alembert equation, nanoscale transport

Janina Kozlowska; Miroslaw Kozlowski; Magdalena Pelc

2006-11-26T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

A Langevin equation description of dynamic nuclear deformation  

SciTech Connect

A model of dynamic nuclear deformation is developed in which the collective degrees of freedom of a nucleus are coupled to subcollective degrees of freedom by means of friction and fluctuation forces in the equations of motion for the collective degrees of freedom. The Langevin equation is a stochastic differential equation that includes friction and fluctuation terms, so it is used as the equation of motion in this model. The necessary inertia and friction parameters are obtained using the Werner-Wheeler approximation, and the fluctuation parameter is obtained by applying the fluctuation-dissipation theorem. It is shown that a second order Runge-Kutta method for numerical solution of the Langevin equation is much better than the commonly employed Euler method. Poor random number generators are shown to have serious negative effects in a Langevin simulation. Several case studies are described, including a model employing the (c, h, [alpha]) shape parameterization with h set equal to zero to reduce it to two dimensions. This parameterization allows scission into fragments of varying relative sizes, providing a suitable model for study for mass distributions, transient times, and the importance of dynamics on distributions and scission rates.

Roeth, N.L.

1992-01-01T23:59:59.000Z

242

Handbook of Industrial Engineering Equations, Formulas, and Calculations  

SciTech Connect

The first handbook to focus exclusively on industrial engineering calculations with a correlation to applications, Handbook of Industrial Engineering Equations, Formulas, and Calculations contains a general collection of the mathematical equations often used in the practice of industrial engineering. Many books cover individual areas of engineering and some cover all areas, but none covers industrial engineering specifically, nor do they highlight topics such as project management, materials, and systems engineering from an integrated viewpoint. Written by acclaimed researchers and authors, this concise reference marries theory and practice, making it a versatile and flexible resource. Succinctly formatted for functionality, the book presents: Basic Math Calculations; Engineering Math Calculations; Production Engineering Calculations; Engineering Economics Calculations; Ergonomics Calculations; Facility Layout Calculations; Production Sequencing and Scheduling Calculations; Systems Engineering Calculations; Data Engineering Calculations; Project Engineering Calculations; and Simulation and Statistical Equations. It has been said that engineers make things while industrial engineers make things better. To make something better requires an understanding of its basic characteristics and the underlying equations and calculations that facilitate that understanding. To do this, however, you do not have to be computational experts; you just have to know where to get the computational resources that are needed. This book elucidates the underlying equations that facilitate the understanding required to improve design processes, continuously improving the answer to the age-old question: What is the best way to do a job?

Badiru, Adedeji B [ORNL; Omitaomu, Olufemi A [ORNL

2011-01-01T23:59:59.000Z

243

Integro-differential equation for Bose-Einstein condensates  

Science Conference Proceedings (OSTI)

We use the assumption that the potential for the A-boson system can be written as a sum of pairwise acting forces to decompose the wave function into Faddeev components that fulfill a Faddeev type equation. Expanding these components in terms of potential harmonic (PH) polynomials and projecting on the potential basis for a specific pair of particles results in a two-variable integro-differential equations suitable for A-boson bound-state studies. The solution of the equation requires the evaluation of Jacobi polynomials P{sub K}{sup {alpha},{beta}}(x) and of the weight function W(z) which give severe numerical problems for very large A. However, using appropriate limits for A{yields}{infinity} we obtain a variant equation which depends only on the input two-body interaction, and the kernel in the integral part has a simple analytic form. This equation can be readily applied to a variety of bosonic systems such as microclusters of noble gasses. We employ it to obtain results for A(set-membership sign)(10-100) {sup 87}Rb atoms interacting via interatomic interactions and confined by an externally applied trapping potential V{sub trap}(r). Our results are in excellent agreement with those previously obtained using the potential harmonic expansion method (PHEM) and the diffusion Monte Carlo (DMC) method.

Adam, R. M. [South African Nuclear Energy Corporation, P.O. Box 582, Pretoria 0001 (South Africa); Sofianos, S. A. [Physics Department, University of South Africa, P.O. Box 392, Pretoria 0001 (South Africa)

2010-11-15T23:59:59.000Z

244

Residential electricity demand: a suggested appliance stock equation  

Science Conference Proceedings (OSTI)

The author develops a simple appliance stock equation for estimating seasonal patterns of power demand elasticity. The equation relates an index of appliances (estimates of typical use) to marginal price per kWh, to income, to average price of alternative fuels, to climate (cooling degree days and heating degree days), to age of the household head, to family size, and to race. Price elasticity is -0.785 for the winter and 0.493 for the summer, with all estimates significant to 0.001. The appliance stock coefficient is 0.801 for the winter and 0.971 for the summer. The equation may be useful in studies that do not require elaborate disaggregation of appliance stock. 7 references, 2 tables.

Garbacz, C.

1984-04-01T23:59:59.000Z

245

Boussinesq approximation of the Cahn-Hilliard-Navier-Stokes equations  

E-Print Network (OSTI)

We study the interactions between the thermodynamic transition and hydrodynamic flows which would characterise a thermo- and hydro-dynamic evolution of a binary mixture in a dissolution/nucleation process. The primary attention is given to the slow dissolution dynamics. The Cahn-Hilliard approach is used to model the behaviour of evolving and diffusing interfaces. An important peculiarity of the full Cahn-Hilliard-Navier-Stokes equations is the use of the full continuity equation required even for a binary mixture of incompressible liquids, firstly, due to dependence of mixture density on concentration and, secondly, due to strong concentration gradients at liquids' interfaces. Using the multiple-scale method we separate the physical processes occurring on different time scales and, ultimately, provide a strict derivation of the Boussinesq approximation for the Cahn-Hilliard-Navier-Stokes equations. This approximation forms a universal theoretical model that can be further employed for a thermo/hydro-dynamic ...

Vorobev, Anatoliy

2010-01-01T23:59:59.000Z

246

Universal estimate of the gradient for parabolic equations  

E-Print Network (OSTI)

We suggest a modification of the estimate for weighted Sobolev norms of solutions of parabolic equations such that the matrix of the higher order coefficients is included into the weight for the gradient. More precisely, we found the upper limit estimate that can be achieved by variations of the zero order coefficient. As an example of applications, an asymptotic estimate was obtained for the gradient at initial time. The constant in the estimates is the same for all possible choices of the dimension, domain, time horizon, and the coefficients of the parabolic equation. As an another example of application, existence and regularity results are obtained for parabolic equations with time delay for the gradient.

Nikolai Dokuchaev

2007-09-06T23:59:59.000Z

247

Field theoretic renormalization group for a nonlinear diffusion equation  

E-Print Network (OSTI)

The paper is an attempt to relate two vast areas of the applicability of the renormalization group (RG): field theoretic models and partial differential equations. It is shown that the Green function of a nonlinear diffusion equation can be viewed as a correlation function in a field-theoretic model with an ultralocal term, concentrated at a spacetime point. This field theory is shown to be multiplicatively renormalizable, so that the RG equations can be derived in a standard fashion, and the RG functions (the $\\beta$ function and anomalous dimensions) can be calculated within a controlled approximation. A direct calculation carried out in the two-loop approximation for the nonlinearity of the form $\\phi^{\\alpha}$, where $\\alpha>1$ is not necessarily integer, confirms the validity and self-consistency of the approach. The explicit self-similar solution is obtained for the infrared asymptotic region, with exactly known exponents; its range of validity and relationship to previous treatments are briefly discussed.

N. V. Antonov; Juha Honkonen

2002-07-02T23:59:59.000Z

248

Gravitation and Spacetime: The Einstein Equation of State Revisited  

E-Print Network (OSTI)

We perform an analysis where Einstein's field equation is derived from two simple thermodynamical relations. First, we assume that the fundamental thermodynamical relation, $\\delta Q = TdS$, is valid at any accelerating spacelike two-plane which moves very close to its local Rindler horizon. The heat flow through the plane, $\\delta Q$, is interpreted here as the boost energy of matter which flows across the past Rindler horizon and which is measured by an observer moving along with the plane. The temperature $T$, in turn, is the Unruh temperature experienced by the observer. Secondly, we assume that when matter flows through the accelerating two-plane, the plane shrinks and the entropy content of matter increases in such a way that the maximum increase in the entropy is, in natural units, exactly one-half of the decrease in the area of the plane. Our analysis supports the view that Einstein's field equation is just a thermodynamical equation of state.

Makela, J; Makela, Jarmo; Peltola, Ari

2006-01-01T23:59:59.000Z

249

Hierarchy of Conservation Laws of Diffusion–Convection Equations  

E-Print Network (OSTI)

We introduce notions of equivalence of conservation laws with respect to Lie symmetry groups for fixed systems of differential equations and with respect to equivalence groups or sets of admissible transformations for classes of such systems. We also revise the notion of linear dependence of conservation laws and define the notion of local dependence of potentials. To construct conservation laws, we develop and apply the most direct method which is effective to use in the case of two independent variables. Admitting possibility of dependence of conserved vectors on a number of potentials, we generalize the iteration procedure proposed by Bluman and Doran-Wu for finding nonlocal (potential) conservation laws. As an example, we completely classify potential conservation laws (including arbitrary order local ones) of diffusion–convection equations with respect to the equivalence group and construct an exhaustive list of locally inequivalent potential systems corresponding to these equations. 1

Roman O. Popovych; Nataliya M. Ivanova

2005-01-01T23:59:59.000Z

250

Quantum-hard-sphere system equations of state revisited  

SciTech Connect

Analytical equations of state for boson and fermion hard-sphere fluids ranging from very low to very high densities are constructed. Such equations of state serve as a zero-order (reference) state upon which to build so-called quantum-thermodynamic-perturbation corrections in describing real but simple quantum fluids at zero temperature. The fluid branch extrapolations from the exact low-density series expansions for the energy are carried out by incorporating various physical arguments, such as close packing densities and residues. Modified London equations of state for the high-density crystalline branch agree very well with computer simulations, and at close packing with certain experimental results at high pressure. Copyright {copyright} 1996 Academic Press, Inc.

Keller, C. [Physics Department, University of South Dakota, Vermillion, South Dakota 57069 (United States); de Llano, M. [Physics Department, North Dakota State University, Fargo, North Dakota 58105 (United States); Ren, S.Z. [Physics Department, University of South Dakota, Vermillion, South Dakota 57069 (United States); Solis, M.A. [Instituto de Fisica, Universidad Nacional Autonoma de Mexico, Apdo. Postal 20-364, 01000 Mexico, DF. (Mexico); Baker, G.A. Jr. [Theoretical Division, University of California, Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

1996-10-01T23:59:59.000Z

251

Solving Potential Scattering Equations without Partial Wave Decomposition  

E-Print Network (OSTI)

Considering two-body integral equations we show how they can be dimensionally reduced by integrating exactly over the azimuthal angle of the intermediate momentum. Numerical solution of the resulting equation is feasible without employing a partial-wave expansion. We illustrate this procedure for the Bethe-Salpeter equation for pion-nucleon scattering and give explicit details for the one-nucleon-exchange term in the potential. Finally, we show how this method can be applied to pion photoproduction from the nucleon with $\\pi N$ rescattering being treated so as to maintain unitarity to first order in the electromagnetic coupling. The procedure for removing the azimuthal angle dependence becomes increasingly complex as the spin of the particles involved increases.

George Caia; Vladimir Pascalutsa; Louis E. Wright

2003-12-08T23:59:59.000Z

252

Generalized Relativistic Wave Equations with Intrinsic Maximum Momentum  

E-Print Network (OSTI)

We examine the nonperturbative effect of maximum momentum on the relativistic wave equations. In momentum representation, we obtain the exact eigen-energies and wavefunctions of one-dimensional Klein-Gordon and Dirac equation with linear confining potentials, and the Dirac oscillator. Bound state solutions are only possible when the strength of scalar potential are stronger than vector potential. The energy spectrum of the systems studied are bounded from above, whereby classical characteristics are observed in the uncertainties of position and momentum operators. Also, there is a truncation in the maximum number of bound states that is allowed. Some of these quantum-gravitational features may have future applications.

Chee Leong Ching; Wei Khim Ng

2013-11-15T23:59:59.000Z

253

Equations of State in the Brans-Dicke cosmology  

E-Print Network (OSTI)

We investigate the Brans-Dicke (BD) theory with the potential as cosmological model to explain the present accelerating universe. In this work, we consider the BD field as a perfect fluid with the energy density and pressure in the Jordan frame. Introducing the power-law potential and the interaction with the cold dark matter, we obtain the phantom divide which is confirmed by the native and effective equation of state. Also we can describe the metric $f(R)$ gravity with an appropriate potential, which shows a future crossing of phantom divide in viable $f(R)$ gravity models when employing the native and effective equations of state.

Hyung Won Lee; Kyoung Yee Kim; Yun Soo Myung

2010-10-27T23:59:59.000Z

254

Equation of State measurements of hydrogen isotopes on Nova  

SciTech Connect

High intensity lasers can be used to perform measurements of materials at extremely high pressures if certain experimental issues can be overcome. We have addressed those issues and used the Nova laser to shock-compress liquid deuterium and obtain measurements of density and pressure on the principal Hugoniot at pressures from 300 kbar to more than 2 Mbar. The data are compared with a number of equation of state models. The data indicate that the effect of molecular dissociation of the deuterium into a monatomic phase may have a significant impact on the equation of state near 1 Mbar.

Collins, G. W., LLNL

1997-11-01T23:59:59.000Z

255

Optimized Schwarz waveform relaxation for Primitive Equations of the ocean  

E-Print Network (OSTI)

In this article we are interested in the derivation of efficient domain decomposition methods for the viscous primitive equations of the ocean. We consider the rotating 3d incompressible hydrostatic Navier-Stokes equations with free surface. Performing an asymptotic analysis of the system with respect to the Rossby number, we compute an approximated Dirichlet to Neumann operator and build an optimized Schwarz waveform relaxation algorithm. We establish the well-posedness of this algorithm and present some numerical results to illustrate the method.

Audusse, Emmanuel; Merlet, Benoit

2009-01-01T23:59:59.000Z

256

Global well-posedness for the homogeneous Landau equation  

E-Print Network (OSTI)

Global well-posedness and exponential decay to equilibrium are proved for the homogeneous Landau equation from kinetic theory. The initial distribution is only assumed to be bounded and decaying sufficiently fast at infinity. In particular, discontinuous initial configurations that might be far from equilibrium are covered. Despite the lack of a comparison principle for the equation, the proof of existence relies on barrier arguments and parabolic regularity theory. Uniqueness and decay to equilibrium are then obtained through weighted integral inequalities. Although the focus is on the spatially homogeneous case with Coulomb potential, the methods introduced here may be applied elsewhere in nonlinear kinetic theory.

Maria Gualdani; Nestor Guillen

2013-05-10T23:59:59.000Z

257

Simulation of the Majorana equation in circuit QED  

E-Print Network (OSTI)

We propose a scheme to simulate the 1D Majorana equation with two Cooper pair boxes coupled to a 1D superconducting transmission line resonator, where strong coupling limit can be achieved. With proper chosen of systematic parameters, we are able to engineer different kinds of interaction, which is indispensable in simulating the Majorana equation in an enlarged real Hilbert space. Measurement of the conserved observable of pseudo-helicity via transmission spectrum of the cavity field can verify the simulated Majorana wave function. The measurement results are experimentally resolvable based on our estimation with conservative parameters.

Sheng Liu; Chuan-Jia Shan; Zhi-Ming Zhang; Zheng-Yuan Xue

2013-04-02T23:59:59.000Z

258

Treating some solid state problems with the Dirac equation  

E-Print Network (OSTI)

The ambiguity involved in the definition of effective-mass Hamiltonians for nonrelativistic models is resolved using the Dirac equation. The multistep approximation is extended for relativistic cases allowing the treatment of arbitrary potential and effective-mass profiles without ordering problems. On the other hand, if the Schrodinger equation is supposed to be used, our relativistic approach demonstrate that both results are coincidents if the BenDaniel and Duke prescription for the kinetic-energy operator is implemented. Applications for semiconductor heterostructures are discussed.

R. Renan; M. H. Pacheco; C. A. S. Almeida

1999-11-22T23:59:59.000Z

259

WKB analysis for nonlinear Schrödinger equations with potential  

E-Print Network (OSTI)

We justify the WKB analysis for the semiclassical nonlinear Schr\\"{o}dinger equation with a subquadratic potential. This concerns subcritical, critical, and supercritical cases as far as the geometrical optics method is concerned. In the supercritical case, this extends a previous result by E. Grenier; we also have to restrict to nonlinearities which are defocusing and cubic at the origin, but besides subquadratic potentials, we consider initial phases which may be unbounded. For this, we construct solutions for some compressible Euler equations with unbounded source term and unbounded initial velocity.

Rémi Carles

2006-01-25T23:59:59.000Z

260

Fluid equations in the presence of electron cyclotron current drive  

Science Conference Proceedings (OSTI)

Two-fluid equations, which include the physics imparted by an externally applied radiofrequency source near electron cyclotron resonance, are derived in their extended magnetohydrodynamic forms using the formalism of Hegna and Callen [Phys. Plasmas 16, 112501 (2009)]. The equations are compatible with the closed fluid/drift-kinetic model developed by Ramos [Phys. Plasmas 17, 082502 (2010); 18, 102506 (2011)] for fusion-relevant regimes with low collisionality and slow dynamics, and they facilitate the development of advanced computational models for electron cyclotron current drive-induced suppression of neoclassical tearing modes.

Jenkins, Thomas G.; Kruger, Scott E. [Tech-X Corporation, 5621 Arapahoe Avenue, Boulder, Colorado 80303 (United States)

2012-12-15T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

Conservation Laws of Multidimensional Diffusion-Convection Equations  

E-Print Network (OSTI)

All possible linearly independent local conservation laws for $n$-dimensional diffusion--convection equations $u_t=(A(u))_{ii}+(B^i(u))_i$ were constructed using the direct method and the composite variational principle. Application of the method of classification of conservation laws with respect to the group of point transformations [R.O. Popovych, N.M. Ivanova, J. Math. Phys., 2005, V.46, 043502 (math-ph/0407008)] allows us to formulate the result in explicit closed form. Action of the symmetry groups on the conservation laws of diffusion equations is investigated and generating sets of conservation laws are constructed.

Nataliya M. Ivanova

2006-04-24T23:59:59.000Z

262

Three-dimensional h-adaptivity for the multigroup neutron diffusion equations Yaqi Wang a  

E-Print Network (OSTI)

(Bell and Glasstone, 1970; Duderstadt and Martin, 1979), an equation that is extraordinarily complicated

Bangerth, Wolfgang

263

Solving the two-body, bound-state Bethe-Salpeter equation  

Science Conference Proceedings (OSTI)

By expanding the solution of the the two-body, bound-state Bethe-Salpeter equation in terms of basis functions that obey the boundary conditions, solutions can be obtained to some, if not many, equations that have heretofore proved intractable. The utility ... Keywords: Bethe-Salpeter equation, bound-state equations

G. B. Mainland

2003-11-01T23:59:59.000Z

264

High order accurate particular solutions of the biharmonic equation on general regions  

Science Conference Proceedings (OSTI)

We present a fast, new method for evaluating particular solutions of the biharmonic equation on general two dimensional regions. The cost of our method is essentially twice the cost of solving Poisson's equation on a regular rectangular region in which ... Keywords: biharmonic equations, finite difference method, integral equations

Anita Mayo

2001-08-01T23:59:59.000Z

265

The Hartman-Grobman theorem for Carathéodory-type differential equations in Banach spaces  

Science Conference Proceedings (OSTI)

Keywords: Carathéodory-type equations, Hartman-Grobman theorem, integral manifolds, measurable time dependence, topological equivalence

Bernd Aulbach; Thomas Wanner

2000-04-01T23:59:59.000Z

266

A real space split operator method for the Klein-Gordon equation  

Science Conference Proceedings (OSTI)

The Klein-Gordon equation is a Lorentz invariant equation of motion for spinless particles. We propose a real space split operator method for the solution of the time-dependent Klein-Gordon equation with arbitrary electromagnetic fields. Split operator ... Keywords: 02.70.-c, 02.70.Bf, 03.65.Pm, Klein-Gordon equation, Numerical simulation, Split operator method

Matthias Ruf; Heiko Bauke; Christoph H. Keitel

2009-12-01T23:59:59.000Z

267

Higher-order quadrature-based moment methods for kinetic equations  

Science Conference Proceedings (OSTI)

Kinetic equations containing terms for spatial transport, body forces, and particle-particle collisions occur in many applications (e.g., rarefied gases, dilute granular gases, fluid-particle flows). The direct numerical solution of the kinetic equation ... Keywords: Boltzmann equation, Dilute particle flows, Kinetic equation, Quadrature method of moments, Rarefied gas flows, Velocity distribution function

R. O. Fox

2009-11-01T23:59:59.000Z

268

Entropy Growth and the Dark Energy Equation of State  

E-Print Network (OSTI)

We revisit the conjecture of a generalized second law of thermodynamics which states that the combined entropy of matter and horizons must grow. In an expanding universe a generalized second law restricts the equation of state. In particular, it conflicts with long phases of a phantom, wstate.

Wilfried Buchmuller; Joerg Jaeckel

2006-10-27T23:59:59.000Z

269

QCD Phase Diagram Using Dyson-Schwinger Equations  

Science Conference Proceedings (OSTI)

We describe briefly the Dyson-Schwinger equation approach of QCD and the study of the QCD phase diagram in this approach. The phase diagram in terms of the temperature and chemical potential, and that in the space of coupling strength and current-quark mass are given.

Liu Yuxin; Qin Sixue; Chang Lei [Department of Physics, Center for High Energy Physics and the State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China); Roberts, Craig D. [Physics Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Department of Physics, Center for High Energy Physics and the State Key Laboratory of Nuclear Physics and Technology, Peking University, Beijing 100871 (China)

2011-05-24T23:59:59.000Z

270

Choosing an Approximation to the Equation of Radiative Transfer  

Science Conference Proceedings (OSTI)

We examine the accuracy of the PL, approximation to the equation of radiative transfer in the presence of scattering/absorbing clouds of various optical thicknesses. We find that very accurate net fluxes can be obtained with the P1, (two-stream) ...

James A. Fillmore; Alan H. Karp

1980-08-01T23:59:59.000Z

271

An improved CSPC equation of state for pure fluids  

Science Conference Proceedings (OSTI)

The three-parameter Cubic Simplified Perturbed Hard-Chain (CSPHC) equation of state (EOS) developed by Wang and Guo (1993) is improved by applying the classical critical point constraints, modifying the attractive term, and introducing the volume translation ... Keywords: CSPHC EOS, phase density, phase equilibrium, pure substance, volume translation

Chang-Yu Sun; Li-Sheng Wang; Guang-Jin Chen; Tian-Min Guo

2002-08-01T23:59:59.000Z

272

Alternative Discrete Energy Solutions to the Free Particle Dirac Equation  

E-Print Network (OSTI)

The usual method of solving the free particle Dirac equation results in the so called continuum energy solutions. Here, we take a different approach and find a set of solutions with quantized energies which are proportional to the total angular momentum.

Brennan, Thomas Edward

2011-01-01T23:59:59.000Z

273

Nonlinear analysis of a reaction-diffusion system: Amplitude equations  

Science Conference Proceedings (OSTI)

A reaction-diffusion system with a nonlinear diffusion term is considered. Based on nonlinear analysis, the amplitude equations are obtained in the cases of the Hopf and Turing instabilities in the system. Turing pattern-forming regions in the parameter space are determined for supercritical and subcritical instabilities in a two-component reaction-diffusion system.

Zemskov, E. P., E-mail: zemskov@ccas.ru [Russian Academy of Sciences, Dorodnicyn Computing Center (Russian Federation)

2012-10-15T23:59:59.000Z

274

An Unconditionally Stable Scheme for the Shallow Water Equations  

Science Conference Proceedings (OSTI)

A finite-difference scheme for solving the linear shallow water equations in a bounded domain is described. Its time step is not restricted by a Courant–Friedrichs–Levy (CFL) condition. The scheme, known as Israeli–Naik–Cane (INC), is the ...

Moshe Israeli; Naomi H. Naik; Mark A. Cane

2000-03-01T23:59:59.000Z

275

National Lab Uses OGJ Data to Develop Cost Equations  

Science Conference Proceedings (OSTI)

For the past 30 years, the Oil and Gas Journal (OGJ) has published data on the costs of onshore and offshore oil and gas pipelines and related equipment. This article describes the methodology employed and resulting equations developed for conceptual capital cost estimating of onshore pipelines. Also described are cost trends uncovered during the course of the analysis.

Brown, Daryl R.; Cabe, James E.; Stout, Tyson E.

2011-01-03T23:59:59.000Z

276

Generalized equation of state for cold superfluid neutron stars  

SciTech Connect

Mature neutron stars are expected to contain various kinds of superfluids in their interiors. Modeling such stars requires the knowledge of the mutual entrainment couplings between the different condensates. We present a unified equation of state describing the different regions of a neutron star with superfluid neutrons and superconducting protons in its core.

Chamel, N.; Goriely, S. [Institut d'Astronomie et d'Astrophysique, Universite Libre de Bruxelles, B-1050 Brussels (Belgium); Pearson, J. M. [Departement de Physique, Universite de Montreal, Montreal (Quebec), H3C 3J7 (Canada)

2011-09-21T23:59:59.000Z

277

Probabilistic relaxation labelling using the Fokker-Planck equation  

Science Conference Proceedings (OSTI)

In this paper we develop a new formulation of probabilistic relaxation labelling using the theory of diffusion processes on graphs. Our aim is to tackle the problem of labelling objects consistently and unambiguously using information concerning label ... Keywords: Data clustering, Diffusion process, Feature correspondence matching, Fokker-Planck equation, Graph theory, Relaxation labelling, Scene labelling

Hongfang Wang; Edwin R. Hancock

2008-11-01T23:59:59.000Z

278

Alternative Discrete Energy Solutions to the Free Particle Dirac Equation  

E-Print Network (OSTI)

The usual method of solving the free particle Dirac equation results in the so called continuum energy solutions. Here, we take a different approach and find a set of solutions with quantized energies which are proportional to the total angular momentum.

Thomas Edward Brennan

2011-10-27T23:59:59.000Z

279

The Green's Function of the Supersymmetric D=1 Heat Equation  

E-Print Network (OSTI)

A rigorous treatment is given of the Green's function of the N=1 supersymmetric heat equation in one spatial dimension with a distribution initial value. The asymptotic expansion of the supersymmetric Green's function as t tends to 0+ is also derived. The coefficients of the expansion generate all the members of the supersymmetric N=1 KdV hierarchy.

S. Andrea; A. Restuccia; A. Sotomayor

2004-01-28T23:59:59.000Z

280

Application of the GRP scheme to open channel flow equations  

Science Conference Proceedings (OSTI)

The GRP (generalized Riemann problem) scheme, originally conceived for gasdynamics, is reformulated for the numerical integration of the shallow water equations in channels of rectangular cross-section, variable width and bed profile, including a friction ... Keywords: Generalized Riemann problem (GRP), Hydraulic jump, Hyperbolic conservation laws, Open channel, Quasi-1D flow, Second-order scheme, Shallow water

A. Birman; J. Falcovitz

2007-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

Formal verification of compiler transformations on polychronous equations  

Science Conference Proceedings (OSTI)

In this paper, adopting the translation validation approach, we present a formal verification process to prove the correctness of compiler transformations on systems of polychronous equations. We encode the source programs and the transformations with ... Keywords: formal verification, multi-clocked synchronous programs, polychronous model, translation validation, validated compiler

Van Chan Ngo; Jean-Pierre Talpin; Thierry Gautier; Paul Le Guernic; Loďc Besnard

2012-06-01T23:59:59.000Z

282

A Weakly Nonlinear Primitive Equation Baroclinic Life Cycle  

Science Conference Proceedings (OSTI)

A weakly nonlinear baroclinic life cycle is examined with a spherical, multilevel, primitive equation model. The structure of the initial zonal jet is chosen so that the disturbance grows very slowly, that is, linear growth rate less than 0.1 day?...

Steven B. Feldstein

1994-01-01T23:59:59.000Z

283

An improved front tracking method for the Euler equations  

Science Conference Proceedings (OSTI)

An improved front tracking method for hyperbolic conservation laws is presented. The improved method accurately resolves discontinuities as well as continuous phenomena. The method is based on an improved front interaction model for a physically more ... Keywords: 35L65, 35L67, 65M12, 76L05, 76N15, Euler equations, Front tracking, Gas dynamics, Hyperbolic conservation laws

J. A. S. Witteveen; B. Koren; P. G. Bakker

2007-06-01T23:59:59.000Z

284

General equations for Biomass Properties Nadge Richard1,2  

E-Print Network (OSTI)

1 General equations for Biomass Properties Nadège Richard1,2 , Henrik Thunman1 1 Department of biomass fuels. The following properties were selected: - the amount of char (Ychar) - the composition: - the temperature of devolatilisation reactor (T) - the heating value of biomass (Hwood) - the ash content

285

Optimal control of the heat equation in an inhomogeneous body  

Science Conference Proceedings (OSTI)

In this paper we consider a heat flow in an inhomogeneous body without internal source. There exists special initial and boundary conditions in this system and we intend to find a convenient coefficient of heat conduction for this body so that body cool ... Keywords: approximation theory, heat equation, linear programming, measure theory

A. H. Borzabadi; A. V. Kamyad; M. H. Farahi

2004-05-01T23:59:59.000Z

286

A Note Basis Properties for Fractional Hydrogen Atom Equation  

E-Print Network (OSTI)

In this paper, spectral analysis of fractional Sturm Liouville problem defined on (0,1], having the singularity of type at zero and research the fundamental properties of the eigenfunctions and eigenvalues for the operator. We show that the eigenvalues and eigenfunctions of the problem are real and orthogonal, respectively. Furthermore,we give some important theorems and lemmas for fractional hydrogen atom equation.

E. Bas; F. Metin

2013-03-12T23:59:59.000Z

287

Scattering of Woods-Saxon Potential in Schrodinger Equation  

E-Print Network (OSTI)

The scattering solutions of the one-dimensional Schrodinger equation for the Woods-Saxon potential are obtained within the position-dependent mass formalism. The wave functions, transmission and reflection coefficients are calculated in terms of Heun's function. These results are also studied for the constant mass case in detail.

Altug Arda; Oktay Aydogdu; Ramazan Sever

2010-09-27T23:59:59.000Z

288

On the solutions of generalized discrete Poisson equation  

E-Print Network (OSTI)

The set of common numerical and analytical problems is introduced in the form of the generalized multidimensional discrete Poisson equation. It is shown that its solutions with square-summable discrete derivatives are unique up to a constant. The proof uses the Fourier transform as the main tool. The necessary condition for the existence of the solution is provided.

Roman Werpachowski

2007-06-19T23:59:59.000Z

289

Dyson-Schwinger equations in the theory of computation  

E-Print Network (OSTI)

Following Manin's approach to renormalization in the theory of computation, we investigate Dyson-Schwinger equations on Hopf algebras, operads and properads of flow charts, as a way of encoding self-similarity structures in the theory of algorithms computing primitive and partial recursive functions and in the halting problem.

Colleen Delaney; Matilde Marcolli

2013-02-20T23:59:59.000Z

290

Numerical calculation of the moments of the population balance equation  

Science Conference Proceedings (OSTI)

The combined CFD-PBM (population balance models) are computationally intensive, so a possibility is to calculate only a few moments of the probability density function (PDF) of the PBM minimizing the computational costs. However, this formulation results ... Keywords: least squares method, population balance equation, quadrature approximation

C. A. Dorao; H. A. Jakobsen

2006-11-01T23:59:59.000Z

291

From Baking a Cake to Solving the Schrodinger Equation  

E-Print Network (OSTI)

The primary emphasis of this study has been to explain how modifying a cake recipe by changing either the dimensions of the cake or the amount of cake batter alters the baking time. Restricting our consideration to the genoise, one of the basic cakes of classic French cuisine, we have obtained a semi-empirical formula for its baking time as a function of oven temperature, initial temperature of the cake batter, and dimensions of the unbaked cake. The formula, which is based on the Diffusion equation, has three adjustable parameters whose values are estimated from data obtained by baking genoises in cylindrical pans of various diameters. The resulting formula for the baking time exhibits the scaling behavior typical of diffusion processes, i.e. the baking time is proportional to the (characteristic length scale)^2 of the cake. It also takes account of evaporation of moisture at the top surface of the cake, which appears to be a dominant factor affecting the baking time of a cake. In solving this problem we have obtained solutions of the Diffusion equation which are interpreted naturally and straightforwardly in the context of heat transfer; however, when interpreted in the context of the Schrodinger equation, they are somewhat peculiar. The solutions describe a system whose mass assumes different values in two different regions of space. Furthermore, the solutions exhibit characteristics similar to the evanescent modes associated with light waves propagating in a wave guide. When we consider the Schrodinger equation as a non-relativistic limit of the Klein-Gordon equation so that it includes a mass term, these are no longer solutions.

Edward A. Olszewski

2005-03-28T23:59:59.000Z

292

Post-Newtonian Celestial Dynamics in Cosmology: Field Equations  

E-Print Network (OSTI)

The present paper outlines theoretical principles of the post-Newtonian mechanics in the expanding universe. It is based upon the gauge-invariant theory of the Lagrangian perturbations of cosmological manifold caused by an isolated astronomical N-body system. We postulate that the background manifold is described by Friedman-Lemaitre-Robertson-Walker (FLRW) metric governed by two primary components - the dark matter and the dark energy. The dark matter is treated as an ideal fluid. The dark energy is described by a single scalar field with a potential which is hold unspecified as long as the theory permits. The Lagrangian of the dark matter and that of the scalar field are formulated in terms of the field variables. We use variational calculus to derive the gauge-invariant field equations of the post-Newtonian celestial mechanics of an isolated astronomical system in an expanding universe. These equations generalize the field equations of the post-Newtonian theory in asymptotically-flat spacetime by taking into account the cosmological effects explicitly. We introduce a new cosmological gauge which generalizes the harmonic gauge of the post-Newtonian theory in asymptotically-flat spacetime. This gauge significantly simplifies the gravitational field equations and allows finding out the approximations where the field equations can be fully decoupled and solved analytically. The residual gauge freedom is explored. The results of the present paper can be useful in the solar system for calculating more precise ephemerides of the solar system bodies on extremely long time intervals, in galactic astronomy to study the dynamics of clusters of galaxies, and in gravitational wave astronomy for discussing the impact of cosmology on generation and propagation of gravitational waves emitted by coalescing binaries and/or merging galactic nuclei.

Sergei Kopeikin; Alexander Petrov

2013-01-24T23:59:59.000Z

293

Inverse Modeling of the Action-Balance Equation. Part I: Source Expansion and Adjoint-Model Equations  

Science Conference Proceedings (OSTI)

In this paper a series of numerical experiments is defined to explore the inverse modeling of the action-balance equation governing the evolution of the surface gravity wave field, using the adjoint data-assimation model-optimization procedure of ...

R. L. Snyder; L. M. Lawson; R. B. Long

1992-12-01T23:59:59.000Z

294

Effective integration of the Nonlinear Vector Schrödinger Equation  

E-Print Network (OSTI)

A comprehensive algebro-geometric integration of the two component Nonlinear Vector Schr\\"odinger equation (Manakov system) is developed. The allied spectral variety is a trigonal Riemann surface, which is described explicitly and the solutions of the equations are given in terms of theta-functions of the surface. The final formulae are effective in that sense that all entries like transcendental constants in exponentials, winding vectors etc. are expressed in terms of prime-form of the curve and well algorithmized operations on them. That made the result available for direct calculations in applied problems implementing the Manakov system. The simplest solutions in Jacobian theta-functions are given as particular case of general formulae and discussed in details.

J. N. Elgin; V. Z. Enolskii; A. R. Its

2005-01-30T23:59:59.000Z

295

NREL: News Feature - Green Computing Helps in Zero Energy Equation  

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

Green Computing Helps in Zero Energy Equation Green Computing Helps in Zero Energy Equation April 14, 2010 Photo of two men watching as a third man goes over blueprints in the data center of NREL's Research Support Facility. Enlarge image Kevin Donovan, data center manager for NREL's Research Support Facility, goes over blueprints with NREL IT project manager Craig Robben and NREL Data Center Coordinator Justin Peltz in the building's data center. The building's cooling system, taking advantage of Colorado's cool nights, is considered key to achieving net-zero energy use when the facility opens this summer. Credit: Pat Corkery It's a daunting challenge erecting the largest net-zero-energy office building in the world. It's especially daunting when that building will be full of people computing, teleconferencing, and generating teraflops of information about

296

Some comments on `Equation for the second virial coefficient`  

E-Print Network (OSTI)

The second viral coefficient calculated using the equation suggested in the paper of Kaplun A.B., Meshalkin A.B. Equation for the second virial coefficient published in High temperature high pressure, 1999, Volume 31, pages 253-258 is compared with experimental data for helium, hydrogen, neon, argon, krypton, xenon, carbon dioxide, water, ammonia, methane, ethylene. It is shown the formula cannot describe the temperature dependence of the experimental data on the second virial coefficient for the all above substances within the experimental error over the investigated temperature interval. The latter is in controversy with the derivations of the paper mentioned above. It is also shown the formula cannot describe the recommended data for the second virial coefficient within their uncertainties for helium, hydrogen, neon, argon, krypton and methane.

Umirzakov, I H

2013-01-01T23:59:59.000Z

297

Control and Stabilization of the Nonlinear Schroedinger Equation on Rectangles  

E-Print Network (OSTI)

This paper studies the local exact controllability and the local stabilization of the semilinear Schr\\"odinger equation posed on a product of $n$ intervals ($n\\ge 1$). Both internal and boundary controls are considered, and the results are given with periodic (resp. Dirichlet or Neumann) boundary conditions. In the case of internal control, we obtain local controllability results which are sharp as far as the localization of the control region and the smoothness of the state space are concerned. It is also proved that for the linear Schr\\"odinger equation with Dirichlet control, the exact controllability holds in $H^{-1}(\\Omega)$ whenever the control region contains a neighborhood of a vertex.

Rosier, Lionel

2010-01-01T23:59:59.000Z

298

Charged anisotropic matter with linear equation of state  

E-Print Network (OSTI)

We consider the general situation of a compact relativistic body with anisotropic pressures in the presence of the electromagnetic field. The equation of state for the matter distribution is linear and may be applied to strange stars with quark matter. Three classes of new exact solutions are found to the Einstein-Maxwell system. This is achieved by specifying a particular form for one of the gravitational potentials and the electric field intensity. We can regain anisotropic and isotropic models from our general class of solution. A physical analysis indicates that the charged solutions describe realistic compact spheres with anisotropic matter distribution. The equation of state is consistent with dark energy stars and charged quark matter distributions. The masses and central densities correspond to realistic stellar objects in the general case when anisotropy and charge are present.

S. Thirukkanesh; S. D. Maharaj

2008-10-21T23:59:59.000Z

299

On Kinetic Equations Modeling Evolution of Systems in Mathematical Biology  

E-Print Network (OSTI)

We develop a rigorous formalism for the description of the kinetic evolution of interacting entities modeling systems in mathematical biology within the framework of the evolution of marginal observables. For this purpose we construct the mean field asymptotic behavior of a solution of the Cauchy problem of the dual BBGKY hierarchy for marginal observables of the dynamical systems based on the Markov jump processes, exhibiting the intrinsic properties of the living entities. The constructed scaling limit is governed by the set of recurrence evolution equations, namely by the dual Vlasov-type hierarchy. Moreover, the relationships of the dual Vlasov hierarchy for the limit marginal observables with the Vlasov-type kinetic equation is established.

Yu. Yu. Fedchun; V. I. Gerasimenko

2013-08-21T23:59:59.000Z

300

Vorticity Preserving Flux Corrected Transport Scheme for the Acoustic Equations  

SciTech Connect

Long term research goals are to develop an improved cell-centered Lagrangian Hydro algorithm with the following qualities: 1. Utilizes Flux Corrected Transport (FCT) to achieve second order accuracy with multidimensional physics; 2. Does not rely on the one-dimensional Riemann problem; and 3. Implements a form of vorticity control. Short term research goals are to devise and implement a 2D vorticity preserving FCT solver for the acoustic equations on an Eulerian mesh: 1. Develop a flux limiting mechanism for systems of governing equations with symmetric wave speeds; 2. Verify the vorticity preserving properties of the scheme; and 3. Compare the performance of the scheme to traditional MUSCL-Hancock and other algorithms.

Lung, Tyler B. [Los Alamos National Laboratory; Roe, Phil [University of Michigan; Morgan, Nathaniel R. [Los Alamos National Laboratory

2012-08-15T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
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301

Equation of state for Entanglement in a Fermi gas  

E-Print Network (OSTI)

Entanglement distance is the maximal separation between two entangled electrons in a degenerate electron gas. Beyond that distance, all entanglement disappears. We relate entanglement distance to degeneracy pressure both for extreme relativistic and non-relativistic systems, and estimate the entanglement distance in a white dwarf. Treating entanglement as a thermodynamical quantity, we relate the entropy of formation and concurrence to relative electron distance, pressure, and temperature, to form a new equation of state for entanglement.

Christian Lunkes; Caslav Brukner; Vlatko Vedral

2004-10-21T23:59:59.000Z

302

U.S. Natural Gas Supply Equation and Price Envelope  

Science Conference Proceedings (OSTI)

This report presents a composite assessment of U.S. natural gas supply and demand balance for the time period 2005 to 2011. The key elements in this outlook, or equation, are changes in supply (rapidly increasing LNG [liquefied natural gas] imports, modest U.S. supply growth, and declining imports from Canada) and in demand (notably, growth for electric power generation and small increases in other sectors). Uncertainties concerning each component are identified and analyzed. While LNG will account for t...

2007-11-05T23:59:59.000Z

303

Nuclear Shadowing and Antishadowing in a Unitarized BFKL Equation  

E-Print Network (OSTI)

The nuclear shadowing and antishadowing effects are explained by a unitarized BFKL equation. The $Q^2$- and $x$-variations of the nuclear parton distributions are detailed based on the level of the unintegrated gluon distribution. In particular, the asymptotical behavior of the unintegrated gluon distribution near the saturation limit in nuclear targets is studied. Our results in the nuclear targets are insensitive to the input distributions if the parameters are fixed by the data of a free proton.

Jianhong Ruan; Zhenqi Shen; Wei Zhu

2008-01-22T23:59:59.000Z

304

Large deviation principles for the stochastic quasigeostrophic equations  

E-Print Network (OSTI)

, University of Bielefeld, D­33615 Bielefeld, Germany E­mail: weiliu@math.uni­bielefeld.de Michael R@mathematik.uni­bielefeld.de Xiang­Chan Zhu School of Science, Beijing Jiaotong University, Beijing 100044, China Department­geostrophic equation in the periodic domain T 2 = R 2 /(2#Z) 2 : ##(t, x) #t = - (t, x) · ##(t, x) - (-#) # #(t, x

Moeller, Ralf

305

Kinetic surface roughening for the Mullins-Herring equation  

E-Print Network (OSTI)

Using the linearity property of the Mullins-Herring equation when the velocity is zero with a Gaussian noise, we obtain an analytic form for the global mean-square surface width and height-height correlation function. This can be used to read the critical exponents in any dimension. In particular for d=1 we show that although the surface is super rough the system exhibits Family-Vicsek scaling behavior.

Esmat Darvish; Amir Ali Masoudi

2008-05-27T23:59:59.000Z

306

A B-spline Galerkin method for the Dirac equation  

E-Print Network (OSTI)

The B-spline Galerkin method is investigated for the simple eigenvalue problem, $y^{\\prime\\prime} = -\\lambda^2 y$. Special attention is give to boundary conditions. From this analysis, we propose a stable method for the Dirac equation and evaluate its accuracy by comparing the computed and exact R-matrix for a wide range of nuclear charges $Z$ and angular quantum numbers $\\kappa$. No spurious solutions were found and excellent agreement was obtained for the R-matrix.

Fischer, Charlotte Froese

2008-01-01T23:59:59.000Z

307

The Nuclear Equation of State at high densities  

E-Print Network (OSTI)

Ab inito calculations for the nuclear many-body problem make predictions for the density and isospin dependence of the nuclear equation-of-state (EOS) far away from the saturation point of nuclear matter. I compare predictions from microscopic and phenomenological approaches. Constraints on the EOS derived from heavy ion reactions, in particular from subthreshold kaon production, as well as constraints from neutron stars are discussed.

Christian Fuchs

2006-10-10T23:59:59.000Z

308

The Dirac equation in Rindler space: A pedagogical introduction  

E-Print Network (OSTI)

A pedagogical introduction to the Dirac equation for massive particles in Rindler space is presented. The spin connection coefficients are explicitly derived using techniques from general relativity. We then apply the Lagrange-Green identity to greatly simplify calculation of the inner products needed to normalize the states. Finally, the Bogolubov coefficients relating the Rindler and Minkowski modes are derived in an intuitive manner. These derivations are useful for students interested in learning about quantum field theory in a curved space-time.

David McMahon; Paul M. Alsing; Pedro Embid

2006-01-03T23:59:59.000Z

309

1-D Dirac Equation, Klein Paradox and Graphene  

E-Print Network (OSTI)

Solutions of the one dimensional Dirac equation with piece-wise constant potentials are presented using standard methods. These solutions show that the Klein Paradox is non-existent and represents a failure to correctly match solutions across a step potential. Consequences of this exact solution are studied for the step potential and a square barrier. Characteristics of massless Dirac states and the momentum linear band energies for Graphene are shown to have quite different current and momentum properties.

S. P. Bowen

2008-07-23T23:59:59.000Z

310

Hamiltonian Dynamics for an alternative action describing Maxwell's equations  

E-Print Network (OSTI)

We develop a complete Dirac's canonical analysis for an alternative action that yields Maxwell's four-dimensional equations of motion. We study in detail the full symmetries of the action by following all steps of Dirac's method in order to obtain a detailed description of symmetries. Our results indicate that such an action does not have the same symmetries than Maxwell theory, namely, the model is not a gauge theory and the number of physical degrees of freedom are different.

Alberto Escalante; Omar Rodríguez Tzompantzi

2013-01-03T23:59:59.000Z

311

Wavepacket Solutions of the Klein-Gordon Equation  

E-Print Network (OSTI)

We find dispersion-free wavepacket solutions to the Klein-Gordon equation, with the only free parameter being the wavepacket velocity $ {\\bf v} $. These wavefunctions are eigenvectors of a velocity operator with commuting components which is symmetric in a certain scalar product space. We show that this velocity operator corresponds to a classical generator which may be obtained by a canonical tranformation from $ {\\bf x}, {\\bf k} $.

Shaun N. Mosley

2007-07-23T23:59:59.000Z

312

Dirac Equation in Noncommutative Space for Hydrogen Atom  

E-Print Network (OSTI)

We consider the energy levels of a hydrogen-like atom in the framework of $\\theta $-modified, due to space noncommutativity, Dirac equation with Coulomb field. It is shown that on the noncommutative (NC) space the degeneracy of the levels $2S_{1/2}, 2P_{1/2}$ and $ 2P_{3/2}$ is lifted completely, such that new transition channels are allowed.

T. C. Adorno; M. C. Baldiotti; M. Chaichian; D. M. Gitman; A. Tureanu

2009-04-18T23:59:59.000Z

313

Thermodynamic Consistency of a Pseudoincompressible Approximation for General Equations of State  

Science Conference Proceedings (OSTI)

In soundproof model equations for geophysical fluid dynamics, the momentum and mechanical energy budgets decouple from the thermodynamics for adiabatic flows. In applying such models to nonadiabatic flows of fluids with general equations of state, ...

Rupert Klein; Olivier Pauluis

2012-03-01T23:59:59.000Z

314

Derivation of Generalized Thomas-Bargmann-Michel-Telegdi Equation for a Particle with Electric Dipole Moment  

E-Print Network (OSTI)

General classical equation of spin motion is explicitly derived for a particle with magnetic and electric dipole moments in electromagnetic fields. Equation describing the spin motion relatively the momentum direction in storage rings is also obtained.

Takeshi Fukuyama; Alexander J. Silenko

2013-08-07T23:59:59.000Z

315

Spectral Transform Methods for Solving the Shallow-Water Equations on the Sphere  

Science Conference Proceedings (OSTI)

The accuracy of computed solutions to several formulations of the shallow-water equations is compared. The shallow-water equations can be written in a number of different forms that are obtained by (a) combining terms into differential ...

Paul N. Swarztrauber

1996-04-01T23:59:59.000Z

316

Oscillation Criteria in First Order Neutral Delay Impulsive Differential Equations with Constant Coefficients  

Science Conference Proceedings (OSTI)

This paper is dealing with the oscillatory properties of first order neutral delay impulsive differential equations and corresponding to them inequalities with constant coefficients. The established sufficient conditions ensure the oscillation of every solution of this type of equations.

Dimitrova, M. B.; Donev, V. I. [Dept. of Mathematics, Technical University of Sofia, branch Sliven, 8800 Sliven (Bulgaria)

2008-10-30T23:59:59.000Z

317

Comments on “The Three-Dimensional Current and Surface Wave Equations  

Science Conference Proceedings (OSTI)

The lowest order sigma-transformed momentum equation given by Mellor takes into account a phase-averaged wave forcing based on Airy wave theory. This equation is shown to be generally inconsistent because of inadequate approximations of the wave ...

Fabrice Ardhuin; Alastair D. Jenkins; Konstadinos A. Belibassakis

2008-06-01T23:59:59.000Z

318

The Contour-Advective Semi-Lagrangian Algorithm for the Shallow Water Equations  

Science Conference Proceedings (OSTI)

A new method for integrating shallow water equations, the contour-advective semi-Lagrangian (CASL) algorithm, is presented. This is the first implementation of a contour method to a system of equations for which exact potential vorticity ...

David G. Dritschel; Lorenzo M. Polvani; Ali R. Mohebalhojeh

1999-07-01T23:59:59.000Z

319

Hadley Cell Dynamics in a Primitive Equation Model. Part I: Axisymmetric Flow  

Science Conference Proceedings (OSTI)

A strategy is adopted that applies the mean meridional circulation (MMC) equation to two different steady states of a primitive equation model. This allows for the investigation of the mechanisms behind the sensitivity of the Hadley cell ...

Hyun-kyung Kim; Sukyoung Lee

2001-10-01T23:59:59.000Z

320

The Liouville Equation and Its Potential Usefulness for the Prediction of Forecast Skill. Part II: Applications  

Science Conference Proceedings (OSTI)

The Liouville equation represents the consistent and comprehensive framework for the treatment of the uncertainty inherent in meteorological forecasts. By its very nature, consideration of the Liouville equation avoids problems that are inherent ...

Martin Ehrendorfer

1994-04-01T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

The Liouville Equation and Its Potential Usefulness for the Prediction of Forecast Skill. Part I: Theory  

Science Conference Proceedings (OSTI)

The Liouville equation provides the framework for the consistent and comprehensive treatment of the uncertainty inherent in meteorological forecasts. This equation expresses the conservation of the phase-space integral of the number density of ...

Martin Ehrendorfer

1994-04-01T23:59:59.000Z

322

CCD noise filtering based on 3-dimensional nonlinear partial differential equation  

Science Conference Proceedings (OSTI)

A three dimensional anisotropic diffusion equation is proposed to remove noise in video sequences. The three dimensional anisotropic diffusion equation utilizes the fact that consecutive frames of high correlation can be obtained in video sequences. ...

Suk Ho Lee; Moon Gi Kang; Kyu Tae Park

1998-08-01T23:59:59.000Z

323

On language equations XXK = XXL and XM = N over a unary alphabet  

Science Conference Proceedings (OSTI)

It is shown that the recently discovered computational universality in systems of language equations over a unary alphabet occurs already in systems of the simplest form, with one unknown X and two equations XXK = XXL and XM = N, ...

Tommi Lehtinen; Alexander Okhotin

2010-08-01T23:59:59.000Z

324

DISCRETE TRANSPARENT BOUNDARY CONDITIONS FOR WIDE ANGLE PARABOLIC EQUATIONS IN UNDERWATER  

E-Print Network (OSTI)

DISCRETE TRANSPARENT BOUNDARY CONDITIONS FOR WIDE ANGLE PARABOLIC EQUATIONS IN UNDERWATER ACOUSTICS "parabolic" equations (WAPEs) in underwater acoustics (assuming cylindrical symmetry). Existing the discretization of transparent bottom boundary conditions. In oceanography one wants to calculate the underwater

Ehrhardt, Matthias

325

Empirical Master Equations. Part II: Application to Stratospheric QBO, Solar Cycle, and Northern Annular Mode  

Science Conference Proceedings (OSTI)

Time series of stratospheric climate variables are used to derive master equations in the discretized phase space spanned by three variables. The empirical master equation (EME) predicts the probability density function (PDF) in this phase space. ...

Mauro Dall’Amico; Joseph Egger

2007-09-01T23:59:59.000Z

326

Exponential Mixing of the 3D Stochastic Navier-Stokes Equations Driven by Mildly Degenerate Noises  

SciTech Connect

We prove the strong Feller property and exponential mixing for 3D stochastic Navier-Stokes equation driven by mildly degenerate noises (i.e. all but finitely many Fourier modes being forced) via a Kolmogorov equation approach.

Albeverio, Sergio [Bonn University, Department of Applied Mathematics (Germany); Debussche, Arnaud, E-mail: arnaud.debussche@bretagne.ens-cachan.fr [ENS Cachan Bretagne and IRMAR Campus de Ker Lann (France); Xu Lihu, E-mail: Lihu.Xu@brunel.ac.uk [Brunel University, Mathematics Department (United Kingdom)

2012-10-15T23:59:59.000Z

327

Representation of Eddies in Primitive Equation Models by a PV Flux  

Science Conference Proceedings (OSTI)

The parametric representation of buoyancy and momentum transport by baroclinic eddies in a primitive equation “? plane” channel is studied through a transformation of the governing equations. Adoption of the“transformed Eulerian mean” and the ...

Richard Wardle; John Marshall

2000-10-01T23:59:59.000Z

328

On the Use of Potential Vorticity Tendency Equations for Diagnosing Atmospheric Dynamics in Numerical Models  

Science Conference Proceedings (OSTI)

This study critically assesses potential vorticity (PV) tendency equations used for analyzing atmospheric convective systems. A generic PV tendency format is presented to provide a framework for comparing PV tendency equations, which isolates the ...

K. J. Tory; J. D. Kepert; J. A. Sippel; C. M. Nguyen

2012-03-01T23:59:59.000Z

329

A NOTE ON THE REGULARITY OF SOLUTIONS OF INFINITE DIMENSIONAL RICCATI EQUATIONS  

Science Conference Proceedings (OSTI)

This note is concerned with the regularity of solutions of algebraic Riccati equations arising from infinite dimensional LQR and LQG control problems. We show that distributed parameter systems described by certain parabolic partial differential equations ...

John A. Burns; Belinda B. King

1994-03-01T23:59:59.000Z

330

Prognostic Equation for Radar Radial Velocity Derived by Considering Atmospheric Refraction and Earth Curvature  

Science Conference Proceedings (OSTI)

The prognostic equation for the radial velocity field observed with a Doppler radar is derived to include the effects of atmospheric refraction and earth curvature on radar-beam height and slope angle. The derived equation, called the radial ...

Qin Xu; Li Wei

2013-10-01T23:59:59.000Z

331

The Deep-Atmosphere Euler Equations in a Generalized Vertical Coordinate  

Science Conference Proceedings (OSTI)

Previous analysis of the hydrostatic primitive equations using a generalized vertical coordinate is extended to the deep-atmosphere nonhydrostatic Euler equations, and some special vertical coordinates of interest are noted. Energy and axial ...

Andrew Staniforth; Nigel Wood

2003-08-01T23:59:59.000Z

332

Efficient Calculation of Infrared Fluxes and Cooling Rates Using the Two-Stream Equations  

Science Conference Proceedings (OSTI)

The calculation of infrared radiative fluxes and cooling rates using the two-stream equations is discussed. It is argued that at infrared wavelengths the two-stream equations are best viewed as an approximation to the differential radiance, the ...

J. M. Edwards

1996-07-01T23:59:59.000Z

333

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

334

Erroneous Use of the Modified Kohler Equation in Cloud and Aerosol Physics Applications  

Science Conference Proceedings (OSTI)

The phase equilibrium equation between water vapor and a liquid droplet is an important tool of cloud physics. Although several different forms of the modified Kohler equation were derived in the past, the authors show that a thermodynamically ...

Petr Chýlek; J. G. D. Wong

1998-04-01T23:59:59.000Z

335

Kadomtsev-Petviashvili equation: Nonlinear self-adjointness and conservation laws  

E-Print Network (OSTI)

The method of nonlinear self-adjointness is applied to the Kadomtsev-Petviashvili equation. The infinite set of conservation laws associated with the infinite algebra of Lie point symmetry of the KP equation is constructed.

Nail H. Ibragimov

2011-10-16T23:59:59.000Z

336

A Pseudoenergy Conservation Law for the Two-Dimensional Primitive Equations  

Science Conference Proceedings (OSTI)

Unbalanced frontogenesis studies frequently employ a mathematical model known as the two-dimensional primitive equations, a reduction of the full three-dimensional primitive equations made by ignoring variations in the meridional direction. Such ...

Murray D. MacKay

1998-07-01T23:59:59.000Z

337

A Non-Iterative Procedure for the Time Integration of the Balance Equations  

Science Conference Proceedings (OSTI)

Recent work by Gent and McWilliams (1982) suggests that of all models intermediate in complexity between quasi-geostrophic (QG) and primitive equation (PE), the balance equations (BE) have the best performance when compared with the standard of ...

Roger Daley

1982-12-01T23:59:59.000Z

338

Equations of magnetodynamics of incompressible thermo-Bingham's fluid under the gravity effect  

Science Conference Proceedings (OSTI)

Keywords: astrophysics, generalized magnetodynamics, geodynamics, global gravity and geomagnetic models of the Earth, partial differential equations, variational inequalities, viscoplasticity

Ji?í Nedoma

1995-04-01T23:59:59.000Z

339

$C^{1,\\al}$ regularity of solutions to parabolic Monge-Amp\\'ere equations  

E-Print Network (OSTI)

We study interior $C^{1, \\al}$ regularity of viscosity solutions of the parabolic Monge-Amp\\'ere equation

Daskalopoulos, Panagiota

2009-01-01T23:59:59.000Z

340

Modified Murnaghan equation of state applied to shock compression of silica, basalt, and dolomite  

DOE Green Energy (OSTI)

An equation of state previously used by the author is developed further and applied to geologic media. The equation is of the same form as the Murnaghan equation of state, but with the elastic constant terms replaced by the cohesive energy density (internal pressure), and the exponential term given as a sum of the Gruneisen parameter and the gaseous adiabatic exponent. Data for shock compression of silica, basalt, and dolomite are analyzed according to the equation.

Rogers, L.A.

1965-12-20T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

Approximate analytical solutions for nonlinear Emden-Fowler type equations by differential transform method  

E-Print Network (OSTI)

In this paper, approximate analytical solutions of nonlinear Emden-Fowler type equations are obtained by the differential transform method (DTM). The DTM is a numerical as well as analytical method for solving integral equations, ordinary and partial diferential equations. To show the efficiency of the DTM, some examples are presented. Comparisons with exact solution show that the DTM is a powerful method for the solution of the nonlinear Emden-Fowler type equations.

Birol Ibis

2012-11-15T23:59:59.000Z

342

Some a priori estimates for a singular evolution equation arising in thin-film dynamics  

Science Conference Proceedings (OSTI)

Keywords: finite extinction time, global Harnack inequality, ill-posed problem, porous-medium equation, thin-film dynamics

Stephen H. Davis; Emmanuele DiBenedetto; David J. Diller

1996-05-01T23:59:59.000Z

343

Numerical solutions of differential equations on FPGA-enhanced computers  

E-Print Network (OSTI)

Conventionally, to speed up scientific or engineering (S&E) computation programs on general-purpose computers, one may elect to use faster CPUs, more memory, systems with more efficient (though complicated) architecture, better software compilers, or even coding with assembly languages. With the emergence of Field Programmable Gate Array (FPGA) based Reconfigurable Computing (RC) technology, numerical scientists and engineers now have another option using FPGA devices as core components to address their computational problems. The hardware-programmable, low-cost, but powerful “FPGA-enhanced computer” has now become an attractive approach for many S&E applications. A new computer architecture model for FPGA-enhanced computer systems and its detailed hardware implementation are proposed for accelerating the solutions of computationally demanding and data intensive numerical PDE problems. New FPGAoptimized algorithms/methods for rapid executions of representative numerical methods such as Finite Difference Methods (FDM) and Finite Element Methods (FEM) are designed, analyzed, and implemented on it. Linear wave equations based on seismic data processing applications are adopted as the targeting PDE problems to demonstrate the effectiveness of this new computer model. Their sustained computational performances are compared with pure software programs operating on commodity CPUbased general-purpose computers. Quantitative analysis is performed from a hierarchical set of aspects as customized/extraordinary computer arithmetic or function units, compact but flexible system architecture and memory hierarchy, and hardwareoptimized numerical algorithms or methods that may be inappropriate for conventional general-purpose computers. The preferable property of in-system hardware reconfigurability of the new system is emphasized aiming at effectively accelerating the execution of complex multi-stage numerical applications. Methodologies for accelerating the targeting PDE problems as well as other numerical PDE problems, such as heat equations and Laplace equations utilizing programmable hardware resources are concluded, which imply the broad usage of the proposed FPGA-enhanced computers.

He, Chuan

2007-05-01T23:59:59.000Z

344

Modified definition of group velocity and electromagnetic energy conservation equation  

E-Print Network (OSTI)

The classical definition of group velocity has two flaws: (a) the group velocity can be greater than the phase velocity in a non-dispersive medium; (b) the definition is not consistent with the principle of relativity. To remove the flaws, a modified definition is proposed. A criterion is set up to identify the justification of group velocity definition. A "superluminal power flow" is constructed to show that the electromagnetic energy conservation equation cannot uniquely define the power flow if the principle of Fermat is not taken into account.

Changbiao Wang

2013-06-13T23:59:59.000Z

345

Real-time nonlinear optimization as a generalized equation.  

SciTech Connect

We establish results for the problem of tracking a time-dependent manifold arising in real-time optimization by casting this as a parametric generalized equation. We demonstrate that if points along a solution manifold are consistently strongly regular, it is possible to track the manifold approximately by solving a single linear complementarity problem (LCP) at each time step. We derive sufficient conditions guaranteeing that the tracking error remains bounded to second order with the size of the time step even if the LCP is solved only approximately. We use these results to derive a fast, augmented Lagrangian tracking algorithm and demonstrate the developments through a numerical case study.

Zavala, V. M.; Anitescu, M. (Mathematics and Computer Science)

2010-11-11T23:59:59.000Z

346

Maxwell Equation for the Coupled Spin-Charge Wave Propagation  

SciTech Connect

We show that the dissipationless spin current in the ground state of the Rashba model gives rise to a reactive coupling between the spin and charge propagation, which is formally identical to the coupling between the electric and the magnetic fields in the 2 + 1 dimensional Maxwell equation. This analogy leads to a remarkable prediction that a density packet can spontaneously split into two counter propagation packets, each carrying the opposite spins. In a certain parameter regime, the coupled spin and charge wave propagates like a transverse 'photon'. We propose both optical and purely electronic experiments to detect this effect.

Bernevig, B.Andrei; Yu, Xiaowei; Zhang, Shou-Cheng; /Stanford U., Phys. Dept.

2010-01-15T23:59:59.000Z

347

Phenomenology of ageing in the Kardar-Parisi-Zhang equation  

E-Print Network (OSTI)

We study ageing during surface growth processes described by the one-dimensional Kardar-Parisi-Zhang equation. Starting from a flat initial state, the systems undergo simple ageing in both correlators and linear responses and its dynamical scaling is characterised by the ageing exponents a=-1/3, b=-2/3, lambda_C=lambda_R=1 and z=3/2. The form of the autoresponse scaling function is well described by the recently constructed logarithmic extension of local scale-invariance.

Malte Henkel; Jae Dong Noh; Michel Pleimling

2011-09-23T23:59:59.000Z

348

Chiral symmetry breaking revisited: the gap equation with lattice ingredients  

Science Conference Proceedings (OSTI)

We study chiral symmetry breaking in QCD, using as ingredients in the quark gap equation recent lattice results for the gluon and ghost propagators. The Ansatz employed for the quark-gluon vertex is purely non-Abelian, introducing a crucial dependence on the ghost dressing function and the quark-ghost scattering amplitude. The numerical impact of these quantities is considerable: the need to invoke confinement explicitly is avoided, and the dynamical quark masses generated are of the order of 300 MeV. In addition, the pion decay constant and the quark condensate are computed, and are found to be in good agreement with phenomenology.

Aguilar, Arlene C. [Federal University of ABC, CCNH, Rua Santa Adelia 166, CEP 09210-170, Santo Andre (Brazil)

2011-05-23T23:59:59.000Z

349

Heart simulation with surface equations for using on MCNP code  

Science Conference Proceedings (OSTI)

External photon beam radiotherapy is carried out in a way to achieve an 'as low as possible' a dose in healthy tissues surrounding the target. One of these surroundings can be heart as a vital organ of body. As it is impossible to directly determine the absorbed dose by heart, using phantoms is one way to acquire information around it. The other way is Monte Carlo method. In this work we have presented a simulation of heart geometry by introducing of different surfaces in MCNP code. We used 14 surface equations in order to determine human heart modeling. Those surfaces are borders of heart walls and contents.

Rezaei-Ochbelagh, D.; Salman-Nezhad, S. [Department of Physics, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil (Iran, Islamic Republic of); Asadi, A. [Department of biology, University of Mohaghegh Ardabili, P.O. Box 179, Ardabil (Iran, Islamic Republic of); Rahimi, A. [Razi Hospital, Rasht (Iran, Islamic Republic of)

2011-12-26T23:59:59.000Z

350

Equation of State Measurements in Liquid Deuterium to 70 Gpa  

DOE Green Energy (OSTI)

Using intense magnetic pressure, a method was developed to launch flyer plates to velocities in excess of 20 km/s. This technique was used to perform plate-impact, shock wave experiments on cryogenic liquid deuterium (LD{sub 2}) to examine its high-pressure equation of state (EOS). Using an impedance matching method, Hugoniot measurements were obtained in the pressure range of 30-70 GPa. The results of these experiments disagree with previously reported Hugoniot measurements of LD{sub 2} in the pressure range above {approx}40 GPa, but are in good agreement with first principles, ab-initio models for hydrogen and its isotopes.

KNUDSON, MARCUS D.; HANSON, DAVID L.; BAILEY, JAMES E.; HALL, CHARLES AINSLEY; ASAY, JAMES R.

2001-12-01T23:59:59.000Z

351

Integral equation for gauge invariant quark Green's function  

E-Print Network (OSTI)

We consider gauge invariant quark two-point Green's functions in which the gluonic phase factor follows a skew-polygonal line. Using a particular representation for the quark propagator in the presence of an external gluon field, functional relations between Green's functions with different numbers of segments of the polygonal lines are established. An integral equation is obtained for the Green's function having a phase factor along a single straight line. The related kernels involve Wilson loops with skew-polygonal contours and with functional derivatives along the sides of the contours.

H. Sazdjian

2008-06-20T23:59:59.000Z

352

Numerical methods for systems of highly oscillatory ordinary differential equations  

E-Print Network (OSTI)

) of the Jacobian or an approx- imation to it, inside the numerical method. Various methods have been developed for the differential equation y(t) = f(y(t)) = Ly(t) +N(y(t)) with y(tn) = yn. 7 1.3 Exponential integrators The first paper to construct what are now... ?(t) = f(yn?1) + f ?(yn?1)(y ? yn?1). The exact solution to this linearised problem is yn = yn?1 + h?1(hf ?(yn?1))f(yn?1), where the function ?1 , is defined as ?1(z) = ez ? 1 z . This method is of order two, for general problems of the form f...

Khanamiryan, Marianna

2010-06-08T23:59:59.000Z

353

Equations of state for self-excited MHD generator studies  

DOE Green Energy (OSTI)

We have constructed a state-of-the-art equation of state (EOS) for argon covering the temperature density range attainable by currently proposed self-excited MHD generators. The EOS for conditions in the flow channel was obtained primarily by a non-ideal plasma code (ACTEX) that is based on a many body activity expansion. For conditions in the driver chamber the EOS was primarily obtained from a fluid code (HDFP) that calculates the fluid properties from perturbation theory based on the insulator interatomic pair potential but including electronic excitations. The results are in agreement with several sets of experimental data in the 0.6 - 91 GPa pressure range.

Rogers, F.J.; Ross, M.; Haggin, G.L.; Wong, L.K.

1980-02-26T23:59:59.000Z

354

On the global solutions of the Higgs boson equation  

E-Print Network (OSTI)

In this article we study global in time (not necessarily small) solutions of the equation for the Higgs boson in the Minkowski and in the de Sitter spacetimes. We reveal some qualitative behavior of the global solutions. In particular, we formulate sufficient conditions for the existence of the zeros of global solutions in the interior of their supports, and, consequently, for the creation of the so-called bubbles, which have been studied in particle physics and inflationary cosmology. We also give some sufficient conditions for the global solution to be an oscillatory in time solution.

Karen Yagdjian

2010-09-16T23:59:59.000Z

355

Inhomogeneous parabolic equations on unbounded metric measure spaces  

E-Print Network (OSTI)

We study inhomogeneous semilinear parabolic equations with source term f independent of time u_{t}={\\Delta}u+u^{p}+f(x) on a metric measure space, subject to the conditions that f(x)\\geq 0 and u(0,x)=\\phi(x)\\geq 0. By establishing Harnack-type inequalities in time t and some powerful estimates, we give sufficient conditions for non-existence, local existence, and global existence of weak solutions. This paper generalizes previous results on Euclidean spaces to general metric measure spaces.

Kenneth J. Falconer; Jiaxin Hu; Yuhua Sun

2011-03-29T23:59:59.000Z

356

Parallel implementation of the Dirac equation in three Cartesian dimensions  

SciTech Connect

We describe the numerical methods used to solve the time-dependent Dirac equation on a three-dimensional Cartesian lattice. Efficient algorithms are required for computationally intensive studies of vacuum-pair production in relativistic heavy-ion collisions. Discretization is achieved through the lattice-collocation method. All numerical procedures reduce to a series of matrix-vector operations which we perform on the Intel iPSC/860 hypercube, making full use of parallelism. We discuss our solutions to the problems of limited node memory and node-to-node communication overhead inherent in using distributed-memory, multiple-instruction, multiple-data stream parallel computers.

Wells, J.C.; Strayer, M.R. [Oak Ridge National Lab., TN (United States); Oberacker, V.E.; Umar, A.S. [Oak Ridge National Lab., TN (United States)]|[Vanderbilt Univ., Nashville, TN (United States). Dept. of Physics and Astronomy

1994-09-01T23:59:59.000Z

357

A scattering view of the Bogoliubov-de Gennes equations  

SciTech Connect

We advocate the use of the T -matrix of the pair potential to study the properties of ultracold Fermi gases in the mean-field approximation. Our approach does not require renormalization procedures even in the limit of contact interaction, and it provides a rigorous definition of the range of the potential. We also rewrite the Bogoliubov-de Gennes equation for the pairing function as a function of the T-matrix, and use it to investigate finite-range effects on the main thermodynamic observables in a gas of {sup 6}Li atoms at unitarity, calculating the pair potential with ab initio quantum chemical methods.

Simonucci, Stefano; Garberoglio, Giovanni; Taioli, Simone [Department of Physics, University of Camerino, via Madonna delle Carceri 9, 62032 Camerino, Italy and Istituto Nazionale di Fisica Nucleare, Sezione di Perugia (Italy); Interdisciplinary Laboratory for Computational Science (LISC), FBK-CMM and University of Trento, via Sommarive 18, I-38123 Trento (Italy); Interdisciplinary Laboratory for Computational Science (LISC), FBK-CMM and University of Trento, via Sommarive 18, I-38123 Trento (Italy) and Department of Physics, University of Trento, Via Sommarive 14, I-38123, Trento, Italy and Istituto Nazionale (Italy)

2012-09-26T23:59:59.000Z

358

A POSTERIORI ESTIMATES FOR THE CAHN--HILLIARD EQUATION WITH OBSTACLE FREE ENERGY  

E-Print Network (OSTI)

A POSTERIORI ESTIMATES FOR THE CAHN--HILLIARD EQUATION WITH OBSTACLE FREE ENERGY L'UBOMĂŤR BA#AS 1 of the standard Cahn--Hilliard equation with a double obstacle free energy. The derived estimates are robust and e algorithm. Keywords: Cahn--Hilliard equation, obstacle free energy, linear finite elements, a posteriori

Banas, Lubomir

359

A Mathematical Method for Exact Analytical Solution of the Schroedinger Equation with Non-central Potential  

Science Conference Proceedings (OSTI)

In this paper, we have studied the Schroedinger equation with central and non-central potential. We have solved the Schroedinger equation in spherical coordinate analytically by using supersymmetric and shape invariance methods. Then we have found the radial and angular parts of wavefunction. Finally the energy eigenvalues of the Schroedinger equation with non-central potential are obtained.

Shojaei, M. R.; Rajabi, A. A. [Department of physics, Shahrood University of Technology (Iran, Islamic Republic of); Momen, Y. [Department of physics, Payamnoor University of Fariman (Iran, Islamic Republic of)

2011-12-26T23:59:59.000Z

360

Short note: Note on coefficient matrices from stochastic Galerkin methods for random diffusion equations  

Science Conference Proceedings (OSTI)

In a recent work by Xiu and Shen [D. Xiu, J. Shen, Efficient stochastic Galerkin methods for random diffusion equations, J. Comput. Phys. 228 (2009) 266-281], the Galerkin methods are used to solve stochastic diffusion equations in random media, where ... Keywords: Galerkin methods, Matrix properties, Stochastic diffusion equations

Tao Zhou; Tao Tang

2010-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

A Legendre--Petrov--Galerkin and Chebyshev Collocation Method for Third-Order Differential Equations  

Science Conference Proceedings (OSTI)

A Legendre--Petrov--Galerkin (LPG) method for the third-order differential equation is developed. By choosing appropriate base functions, the method can be implemented efficiently. Also, this new approach enables us to derive an optimal rate of convergence ... Keywords: Korteweg--de Vries equation, Legendre--Petrov--Galerkin and Chebyshev collocation, third-order differential equation

Heping Ma; Weiwei Sun

2000-10-01T23:59:59.000Z

362

A direct matrix method for computing analytical Jacobians of discretized nonlinear integro-differential equations  

Science Conference Proceedings (OSTI)

In this article, we present a simple direct matrix method for analytically computing the Jacobian of nonlinear algebraic equations that arise from the discretization of nonlinear integro-differential equations. The method is based on a formulation of ... Keywords: Analytical Jacobian, Integro-differential equations, Matrix calculus, Newton's method, Numerical methods

Kevin T. Chu

2009-08-01T23:59:59.000Z

363

A general framework for surface modeling using geometric partial differential equations  

Science Conference Proceedings (OSTI)

In this paper, a general framework for surface modeling using geometric partial differential equations (PDEs) is presented. Starting with a general integral functional, we derive an Euler-Lagrange equation and then a geometric evolution equation (also ... Keywords: Geometric PDEs, Surface modeling, Triangular surface mesh

Guoliang Xu; Qin Zhang

2008-03-01T23:59:59.000Z

364

A fast iterative solver for the variable coefficient diffusion equation on a disk  

Science Conference Proceedings (OSTI)

We present an efficient iterative method for solving the variable coefficient diffusion equation on a unit disk. The equation is written in polar coordinates and is discretized by the standard centered difference approximation under the grid arrangement ... Keywords: Ginzburg-Landau vortices, iterative method, polar coordinates, variable diffusion equation

Ming-Chih Lai; Yu-Hou Tseng

2005-09-01T23:59:59.000Z

365

Parabolic equation modeling of high frequency acoustic transmission with an evolving sea surface  

E-Print Network (OSTI)

Parabolic equation modeling of high frequency acoustic transmission with an evolving sea surface J is combined with a rough surface formulation of a parabolic equation model for predicting time an approximation of the time-varying acoustic field. The wide-angle parabolic equation model manages the rough sea

Archer, Cristina Lozej

366

Elastic parabolic equation solutions for underwater acoustic problems using seismic sources  

E-Print Network (OSTI)

Elastic parabolic equation solutions for underwater acoustic problems using seismic sources Scott D theoretic methods, and attempts to model them with fluid-bottom parabolic equation solu- tions suggest between elastic and acoustic waves, current elastic parabolic equation solutions must be modified to allow

367

ERROR ESTIMATES FOR FINITE DIFFERENCE METHODS FOR A WIDE-ANGLE `PARABOLIC' EQUATION  

E-Print Network (OSTI)

ERROR ESTIMATES FOR FINITE DIFFERENCE METHODS FOR A WIDE-ANGLE `PARABOLIC' EQUATION G. D. AKRIVIS-value problem for a third-order p.d.e., a wide-angle `parabolic' equation frequently used in underwater. wide-angle `parabolic' equation, Underwater Acoustics, finite difference error esti- mates, interface

Akrivis, Georgios

368

Two parabolic equations for propagation in layered poro-elastic media  

E-Print Network (OSTI)

Two parabolic equations for propagation in layered poro-elastic media Adam M. Metzlera) Applied 10 October 2012; revised 26 March 2013; accepted 9 May 2013) Parabolic equation methods for fluid. A previous parabolic equation solution for one model of range-independent poro-elastic media [Collins et al

369

MLPG method for two-dimensional diffusion equation with Neumann's and non-classical boundary conditions  

Science Conference Proceedings (OSTI)

In this paper, a meshless local Petrov-Galerkin (MLPG) method is presented to treat parabolic partial differential equations with Neumann's and non-classical boundary conditions. A difficulty in implementing the MLPG method is imposing boundary conditions. ... Keywords: Finite differences, Heat equation, MLPG method, Neumann's boundary conditions, Non-classical integral boundary condition, Parabolic partial differential equations

S. Abbasbandy; A. Shirzadi

2011-02-01T23:59:59.000Z

370

Multilinear Volterra equations of the first kind and some problems of control  

Science Conference Proceedings (OSTI)

Elements of the theory of the multilinear Volterra equations of the first kind relying on the notion of corresponding majorant (integral, differential, functional) equations were set forth. The relation between the simplest majorant equations and special ... Keywords: 02.30.Rz

A. S. Apartsin

2008-04-01T23:59:59.000Z

371

Darboux transformations for (1+2)-dimensional Fokker-Planck equations with constant diffusion matrix  

SciTech Connect

We construct a Darboux transformation for (1+2)-dimensional Fokker-Planck equations with constant diffusion matrix. Our transformation is based on the two-dimensional supersymmetry formalism for the Schroedinger equation. The transformed Fokker-Planck equation and its solutions are obtained in explicit form.

Schulze-Halberg, Axel [Department of Mathematics and Actuarial Science, Indiana University Northwest, 3400 Broadway, Gary, Indiana 46408 (United States)

2012-10-15T23:59:59.000Z

372

Physics 214 Winter 2013 The Poisson equation and the inverse Laplacian  

E-Print Network (OSTI)

and its solution We wish to solve the Poisson equation, 2 = -4 , (1) given a known charge distribution (r surface). The solution will take the form, (r) = p(r) + c(r) , (2) where p(r) is a particular solution to the Poisson equation and c(r) is the (comple- mentary) solution to the Laplace equation, 2 c(r) = 0

California at Santa Cruz, University of

373

Felix Bloch, Nuclear Induction, Bloch Equations, Bloch Theorem, Bloch  

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

Felix Bloch, Nuclear Induction, and Bloch Equations Felix Bloch, Nuclear Induction, and Bloch Equations Resources with Additional Information Stressing "the importance both of demonstrating the neutron's magnetic moment and of determining its magnitude", Felix Bloch began his research on neutron physics at Stanford [University] in early 1936. "Using mostly X-ray and microwave equipment from the physics labs, he and Norris Bradbury ... built [a neutron] source ... . (Bloch later pointed out that this equipment was more important as a source of inspiration than of neutrons.) Eventually, he extended his use of neutron sources to studies of neutron polarisation, a link to his earlier research in ferromagnetism. Felix Bloch Courtesy Stanford University Archives These studies served as a basis for a collaborative effort with Luis Alvarez ... . In the fall of 1938, Alvarez and Bloch began working with Berkeley's 37" cyclotron to determine the magnetic moment of the neutron. ... By the summer of 1939 ... they were able to publish very precise results. This experiment was, in fact, one of the first important uses of Ernest Lawrence's cyclotron. ..

374

Equation of state and phase diagram of FeO  

Science Conference Proceedings (OSTI)

Wuestite, Fe{sub 1-x}O, is an important component in the mineralogy of Earth's lower mantle and may also be a component in the core. Therefore the high pressure, high temperature behavior of FeO, including its phase diagram and equation of state, is essential knowledge for understanding the properties and evolution of Earth's deep interior. We performed X-ray diffraction measurements using a laser-heated diamond anvil cell to achieve simultaneous high pressures and temperatures. Wuestite was mixed with iron metal, which served as our pressure standard, under the assumption that negligible oxygen dissolved into the iron. Our data show a positive slope for the subsolidus phase boundary between the B1 and B8 structures, indicating that the B1 phase is stable at the P-T conditions of the lower mantle and core. We have determined the thermal equation of state of B1 FeO to 156 GPa and 3100 K, finding an isothermal bulk modulus K{sub 0} = 149.4 {+-} 1.0 GPa and its pressure derivative K'{sub 0} = 3.60 {+-} 0.4. This implies that 7.7 {+-} 1.1 wt.% oxygen is required in the outer core to match the seismologically-determined density, under the simplifying assumption of a purely Fe-O outer core.

Fischer, Rebecca A.; Campbell, Andrew J.; Shofner, Gregory A.; Lord, Oliver T.; Dera, Przemyslaw; Prakapenka, Vitali B. (Bristol); (Maryland); (UC)

2012-04-11T23:59:59.000Z

375

Dyson-Schwinger Equations: Density, Temperature and Continuum Strong QCD  

E-Print Network (OSTI)

Continuum strong QCD is the application of models and continuum quantum field theory to the study of phenomena in hadronic physics, which includes; e.g., the spectrum of QCD bound states and their interactions; and the transition to, and properties of, a quark gluon plasma. We provide a contemporary perspective, couched primarily in terms of the Dyson-Schwinger equations but also making comparisons with other approaches and models. Our discourse provides a practitioners' guide to features of the Dyson-Schwinger equations [such as confinement and dynamical chiral symmetry breaking] and canvasses phenomenological applications to light meson and baryon properties in cold, sparse QCD. These provide the foundation for an extension to hot, dense QCD, which is probed via the introduction of the intensive thermodynamic variables: chemical potential and temperature. We describe order parameters whose evolution signals deconfinement and chiral symmetry restoration, and chronicle their use in demarcating the quark gluon plasma phase boundary and characterising the plasma's properties. Hadron traits change in an equilibrated plasma. We exemplify this and discuss putative signals of the effects. Finally, since plasma formation is not an equilibrium process, we discuss recent developments in kinetic theory and its application to describing the evolution from a relativistic heavy ion collision to an equilibrated quark gluon plasma.

C. D. Roberts; S. M. Schmidt

2000-05-24T23:59:59.000Z

376

Methods for Diffusive Relaxation in the $P_N$ Equations  

Science Conference Proceedings (OSTI)

This study will investigate several numerical methods for modeling the transfer of neutral particles through a material medium, such as neutrons within a nuclear reactor. In a kinetic description, the particle evolution is governed by a transport equation, generally of the form (1.1) {partial_derivative}{sub t}F + v {center_dot} {del}{sub x}F = C(F). Here x {element_of} {Omega} {contained_in} R{sup 3} is a spatial coordinate, v {element_of} R{sup 3} is a velocity coordinate, t {ge} 0 is time, and the function F = F(x, v, t) is the non-negative distribution of particles in position-velocity phase space. The left-hand side of (1.1) describes the evolution of F along inertial trajectories, while the collision operator C on the right-hand side describes particle interactions with the medium via scattering and absorption/emission processes. Typically, there exists a diffusion limit for (1.1) in which F is approximated by a non-negative scalar function of space and time that satisfies a standard diffusion equation. This approximation is valid when collision processes dominate; i.e., when the mean free path between collisions is small compared to macroscopic variations in the system. Because collisions drive particles into equilibrium with the surrounding medium, long time scales (relative to the collision process) are required in order to observe diffusion dynamics. A common approach to solving (1.1) is with moment methods. In the moment approach, one tracks the evolution of a finite number of velocity moments of F. These moments, which are functions of space and time only, can then be used to reconstruct an approximation of F. Their evolution is approximated by a system of partial differential equations that are derived directly from (1.1). The exact form of these equations and the reconstruction of F is known as the closure problem. A basic requirement of any closure is that the resulting moment system has the same diffusion limit as the transport equation (1.1). Moment equations play an important role in so-called transition regimes, where collisions are frequent enough to impose macroscopic structure onto a particle system, but not frequent enough to validate the diffusion limit. Roughly speaking, as the number of particle interactions decreases, the system becomes less organized and more moments are needed for an accurate approximation of F. Thus simulations of multiscale transport phenomena can use moment equations in three fundamental ways: (1) As stand-alone models, with the flexibility to improve accuracy by adding more moments; (2) As preconditioners for more complicated models that may suffer from numerical stiffness; (3) In hybrid schemes that select components from a hierarchy of models in such a way as to maximize efficiency for a given level of accuracy. Thus additional moments, which can become computationally expensive, are used only in regimes where they are needed. For numerical simulations, the hyperbolic nature of many moment systems and the parabolic nature of the diffusion approximation are not always compatible. In such cases, the simulation of multi-scale problems with multiple temporal and spatial scales can be a challenge. In practice, there is a need for hyperbolic solvers that can handle shocks and discontinuities associated with streaming regimes (when the collisions are less frequent), but also behave like standard diffusion solvers in diffusive regimes. In particular, a hyperbolic solver should, in a specific asymptotic limit, reduce to a discretization of the relevant diffusion equation. This is the so-called asymptotic preserving property [27]. Unfortunately, hyperbolic solvers use numerical dissipation to capture discontinuities, and unless formulated carefully, this dissipation increases as the system approaches the diffusion limit. At some point in this limit process, the numerical dissipation dominates the actual physical diffusion in the system. Consequently, one may generate results which appear very well resolved, but are far from accurate. Another drawback of conventional hyperbolic so

Hauck, Cory D [ORNL; Lowrie, Robert B. [Los Alamos National Laboratory (LANL); Ryan, McClarren [Texas A& M University

2009-01-01T23:59:59.000Z

377

The OPAL Equation of State and Low Metallicity Isochrones  

E-Print Network (OSTI)

The Yale stellar evolution code has been modified to use the OPAL equation of state tables (Rogers 1994). Stellar models and isochrones were constructed for low metallicity systems ($-2.8 \\le [Fe/H] \\le -0.6$). Above $M\\sim 0.7\\,\\msun$, the isochrones are very similar to those which are constructed using an equation of state which includes the analytical Debye-Huckel correction at high temperatures. The absolute magnitude of the main sequence turn-off (\\mvto) with the OPAL or Debye-Huckel isochrones is about 0.06 magnitudes fainter, at a given age, than \\mvto derived from isochrones which do not include the Debye-Huckel correction. As a consequence, globular clusters ages derived using \\mvto are reduced by 6 -- 7\\% as compared to the ages determined from the standard isochrones. Below $M\\sim 0.7\\,\\msun$, the OPAL isochrones are systematically hotter (by approximately 0.04 in B-V) at a given magnitude as compared to the standard, or Debye-Huckel isochrones. However, the lower mass models fall out of the OPAL table range, and this could be the cause of the differences in the location of the lower main-sequences.

Brian Chaboyer; Yong --Cheol Kim

1995-06-19T23:59:59.000Z

378

Sonoluminescence test for equation of state in warm dense matter  

SciTech Connect

In experiments of Single-bubble Sonoluminescence (SBSL), the bubble is heated to temperatures of a few eV in the collapse phase of the oscillation. Our hydrodynamic simulations show that the density inside the bubble can go up to the order of 1 g/cm3, and the electron density due to ionization is 1021 /cm3. So the plasma coupling constant is found to be around 1 and the gas inside the bubble is in the Warm Dense Matter (WDM) regime. We simulate the light emission of SL with an optical model for thermal radiation which takes the finite opacity of the bubble into consideration. The numerical results obtained are compared to the experimental data and found to be very sensitive to the equation of state used. As theories for the equation of state, as well as the opacity data, in the WDM regime are still very uncertain, we propose that SL may be a good low-cost experimental check for the EOS and the opacity data for matter in the WDM regime.

Ng, Siu-Fai; Barnard, J.J.; Leung, P.T.; Yu, S.S.

2008-08-01T23:59:59.000Z

379

Minimal Liouville Gravity correlation numbers from Douglas string equation  

E-Print Network (OSTI)

We continue the study of $(q,p)$ Minimal Liouville Gravity with the help of Douglas string equation. We generalize the results of \\cite{Moore:1991ir}, \\cite{Belavin:2008kv}, where Lee-Yang series $(2,2s+1)$ was studied, to $(3,3s+p_0)$ Minimal Liouville Gravity, where $p_0=1,2$. We demonstrate that there exist such coordinates $\\tau_{m,n}$ on the space of the perturbed Minimal Liouville Gravity theories, in which the partition function of the theory is determined by the Douglas string equation. The coordinates $\\tau_{m,n}$ are related in a non-linear fashion to the natural coupling constants $\\lambda_{m,n}$ of the perturbations of Minimal Lioville Gravity by the physical operators $O_{m,n}$. We find this relation from the requirement that the correlation numbers in Minimal Liouville Gravity must satisfy the conformal and fusion selection rules. After fixing this relation we compute three- and four-point correlation numbers when they are not zero. The results are in agreement with the direct calculations in Minimal Liouville Gravity available in the literature \\cite{Goulian:1990qr}, \\cite{Zamolodchikov:2005sj}, \\cite{Belavin:2006ex}.

Alexander Belavin; Boris Dubrovin; Baur Mukhametzhanov

2013-10-21T23:59:59.000Z

380

The QCD phase diagram from Schwinger-Dyson Equations  

E-Print Network (OSTI)

We study the phase diagram of quantum chromodynamics (QCD). For this purpose we employ the Schwinger-Dyson equations (SDEs) technique and construct a truncation of the infinite tower of equations by demanding a matching with the lattice results for the quark-anti-quark condensate at finite temperature (T), for zero quark chemical potential (mu), that is, the region where lattice calculations are expected to provide reliable results. We compute the evolution of the phase diagram away from T=0 for increasing values of the chemical potential by following the evolution of the heat capacity as a function of T and mu. The behavior of this thermodynamic variable clearly demonstrates the existence of a cross-over for mu less than a critical value. However, the heat capacity develops a singularity near mu approx 0.22 GeV marking the onslaught of a first order phase transition characterized by the existence of a critical point. The critical line continues until mu approx 0.53 GeV where Tc=0 and thus chiral symmetry is finally restored.

Enif Gutierrez; Aftab Ahmad; Alejandro Ayala; Adnan Bashir; Alfredo Raya

2013-04-30T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

Boundary conditions for Einstein's field equations: Analytical and numerical analysis  

E-Print Network (OSTI)

Outer boundary conditions for strongly and symmetric hyperbolic formulations of 3D Einstein's field equations with a live gauge condition are discussed. The boundary conditions have the property that they ensure constraint propagation and control in a sense made precise in this article the physical degrees of freedom at the boundary. We use Fourier-Laplace transformation techniques to find necessary conditions for the well posedness of the resulting initial-boundary value problem and integrate the resulting three-dimensional nonlinear equations using a finite-differencing code. We obtain a set of constraint-preserving boundary conditions which pass a robust numerical stability test. We explicitly compare these new boundary conditions to standard, maximally dissipative ones through Brill wave evolutions. Our numerical results explicitly show that in the latter case the constraint variables, describing the violation of the constraints, do not converge to zero when resolution is increased while for the new boundary conditions, the constraint variables do decrease as resolution is increased. As an application, we inject pulses of ``gravitational radiation'' through the boundaries of an initially flat spacetime domain, with enough amplitude to generate strong fields and induce large curvature scalars, showing that our boundary conditions are robust enough to handle nonlinear dynamics. We expect our boundary conditions to be useful for improving the accuracy and stability of current binary black hole and binary neutron star simulations, for a successful implementation of characteristic or perturbative matching techniques, and other applications. We also discuss limitations of our approach and possible future directions.

Olivier Sarbach; Manuel Tiglio

2004-12-22T23:59:59.000Z

382

Equations for static vacuum solutions arising from trace dynamics modifications to gravitation  

E-Print Network (OSTI)

We derive the equations governing static, spherically symmetric vacuum solutions to the Einstein equations as modified by the frame-dependent effective action arising from trace dynamics. We give several equivalent forms of the master second order, nonlinear differential equation implied by the trace dynamics effective action, and calculate the leading perturbative correction to the Schwarzschild metric. We then analyze the master equation in the regimes $r \\to 0$, $r \\to \\infty$, and $0symmetric case, we calculate the leading effective action corrections to the spatial components of the Einstein equations, which furnish the starting point for a similar analysis (yet to be done) of the static, axially symmetric case.

Stephen L. Adler

2013-08-07T23:59:59.000Z

383

Global Dissipativity and Inertial Manifolds for Diffusive Burgers Equations with Low-Wavenumber Instability  

E-Print Network (OSTI)

Global well-posedness, existence of globally absorbing sets and existence of inertial manifolds is investigated for a class of diffusive Burgers equations. The class includes diffusive Burgers equation with nontrivial forcing, the Burgers-Sivashinsky equation and the Quasi-Stedy equation of cellular flames. The global dissipativity is proven in 2D for periodic boundary conditions. For the proof of the existence of inertial manifolds, the spectral-gap condition, which Burgers-type equations do not satisfy in its original form is circumvented by the Cole-Hopf transform. The procedure is valid in both one and two space dimensions.

Jesenko Vukadinovic

2009-05-09T23:59:59.000Z

384

Alterations of the Climate of a Primitive Equation Model produced by Filtering Approximations and Subsequent Tuning and Stochastic Forcing  

Science Conference Proceedings (OSTI)

The simulated climates of highly truncated nonlinear models based on the primitive equations (PE), balance equations (BE) and quasi-geostrophic (QG) equations are compared, in order to determine the effects of the filtering approximations. The ...

Ross N. Hoffman

1981-03-01T23:59:59.000Z

385

(I,J) similar solutions to Euler and Navier-Stokes equations  

E-Print Network (OSTI)

In this paper we introduce (I,J) similar method for incompressible two and three dimensional Euler equations and Navier-Stokes equations, obtain a series of explicit (I,J) similar solutions to the incompressible two dimensional Euler equations, they include all of twin wave solutions, some new singularity solutions, and some global smooth solutions with finite energy. We also discover that twin wave solution and affine solution to two dimensional incompressible Euler equations are respectively plane wave and constant vector. Finally, we supply some explicit piecewise smooth solutions to incompressible three dimensional Euler and an example to incompressible three dimensional Navier-Stokes equations which indicates that viscosity limit of a solution to Navier-Stokes equations does not need to be a solution to Euler equations.

Ganshan Yang

2013-07-13T23:59:59.000Z

386

New Improved Equations For Na-K, Na-Li And Sio2 Geothermometers By Outlier  

Open Energy Info (EERE)

Improved Equations For Na-K, Na-Li And Sio2 Geothermometers By Outlier Improved Equations For Na-K, Na-Li And Sio2 Geothermometers By Outlier Detection And Rejection Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: New Improved Equations For Na-K, Na-Li And Sio2 Geothermometers By Outlier Detection And Rejection Details Activities (1) Areas (1) Regions (0) Abstract: We present new improved equations for three still widely used Na/K, Na/Li and SiO2 geothermometers (obtained by statistical treatment of the data and application of outlier detection and rejection as well as theory of error propagation) and compare them with those by Fournier and others. New equations are also developed for estimating errors associated with the use of these new geothermometric equations and comparing them with the performance of the original equations. The errors in the use of the new

387

Transport in the spatially tempered, fractional Fokker-Planck equation  

SciTech Connect

A study of truncated Levy flights in super-diffusive transport in the presence of an external potential is presented. The study is based on the spatially tempered, fractional Fokker-Planck (TFFP) equation in which the fractional diffusion operator is replaced by a tempered fractional diffusion (TFD) operator. We focus on harmonic (quadratic) potentials and periodic potentials with broken spatial symmetry. The main objective is to study the dependence of the steady-state probability density function (PDF), and the current (in the case of periodic potentials) on the level of tempering, lambda, and on the order of the fractional derivative in space, alpha. An expansion of the TFD operator for large lambda is presented, and the corresponding equation for the coarse grained PDF is obtained. The steady-state PDF solution of the TFFP equation for a harmonic potential is computed numerically. In the limit lambda -> infinity, the PDF approaches the expected Boltzmann distribution. However, nontrivial departures from this distribution are observed for finite (lambda > 0) truncations, and alpha not equal 2. In the study of periodic potentials, we use two complementary numerical methods: a finite-difference scheme based on the Grunwald-Letnikov discretization of the truncated fractional derivatives and a Fourier-based spectral method. In the limit lambda -> infinity, the PDFs converges to the Boltzmann distribution and the current vanishes. However, for alpha not equal 2, the PDF deviates from the Boltzmann distribution and a finite non-equilibrium ratchet current appears for any lambda > 0. The current is observed to converge exponentially in time to the steady-state value. The steady-state current exhibits algebraical decay with lambda, as J similar to lambda(-zeta), for alpha >= 1.75. However, for alpha <= 1.5, the steady-state current decays exponentially with lambda, as J similar to e(-xi lambda). In the presence of an asymmetry in the TFD operator, the tempering can lead to a current reversal. A detailed numerical study is presented on the dependence of the current on lambda and the physical parameters of the system.

Kullberg, A. [University of California, Los Angeles; Del-Castillo-Negrete, Diego B [ORNL

2012-01-01T23:59:59.000Z

388

Disastrous Equations J. Douglas Wright Drexel University Department  

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

Disastrous Disastrous Equations J. Douglas Wright Drexel University Department of Mathematics Science on Saturday 1 Earthquakes far out in the ocean gener- ate massive water waves called tsunami. When such waves hit coastlines they can cause massive damage. 2 The 2004 Indian Ocean Tsunami: 100' waves. 230,000 deaths. (photo by David Rydevik) 3 The 2011 TÂŻ ohoku Tsunami: 130' waves. 15,000 deaths + Nuclear accidents. (photo from National Geographic) 4 The 2011 TÂŻ ohoku Tsunami: 130' waves. 15,000 deaths + Nuclear accidents. (photo from National Geographic) 5 6 7 8 Tsunami behavior The waves which leave from the quake zone: 1. are NOT very high, around five feet; 2. are extremely wide, around one hundred miles; 3. move very fast, order of 500 mph; 4. go long distances, like halfway around the world, and do not "disperse" as they travel. 9 Tsunami behavior So long as they are in deep water,

389

A Master equation approach to modeling an artificial protein motor  

E-Print Network (OSTI)

Linear bio-molecular motors move unidirectionally along a track by coordinating several different processes, such as fuel (ATP) capture, hydrolysis, conformational changes, binding and unbinding from a track, and center-of-mass diffusion. A better understanding of the interdependencies between these processes, which take place over a wide range of different time scales, would help elucidate the general operational principles of molecular motors. Artificial molecular motors present a unique opportunity for such a study because motor structure and function are a priori known. Here we describe use of a Master equation approach, integrated with input from Langevin and molecular dynamics modeling, to stochastically model a molecular motor across many time scales. We apply this approach to a specific concept for an artificial protein motor, the Tumbleweed.

Kuwada, Nathan J; Linke, Heiner

2010-01-01T23:59:59.000Z

390

A Master equation approach to modeling an artificial protein motor  

E-Print Network (OSTI)

Linear bio-molecular motors move unidirectionally along a track by coordinating several different processes, such as fuel (ATP) capture, hydrolysis, conformational changes, binding and unbinding from a track, and center-of-mass diffusion. A better understanding of the interdependencies between these processes, which take place over a wide range of different time scales, would help elucidate the general operational principles of molecular motors. Artificial molecular motors present a unique opportunity for such a study because motor structure and function are a priori known. Here we describe use of a Master equation approach, integrated with input from Langevin and molecular dynamics modeling, to stochastically model a molecular motor across many time scales. We apply this approach to a specific concept for an artificial protein motor, the Tumbleweed.

Nathan J. Kuwada; Gerhard A. Blab; Heiner Linke

2010-04-07T23:59:59.000Z

391

Solar Models: Influence of Equation of State and Opacity  

E-Print Network (OSTI)

Solar models through evolutionary phases of gravitational contraction, pre-main sequence and MS phases, up to current age 4.5E9 yr. and 4.57E9 yr., were studied adopting different prescriptions for the equation of state (EOS) and different opacity tables. The results are compared with solar models we computed with different radiative opacities (Cox & Stewart 1970) and different EOS, as with models computed by other authors. Finally we provide the internal run of the thermodynamic quantities of our preferred solar model which possesses the following characteristics: age 4.50E9 yr., initial He abundance by mass 0.285, parameter of the mixing length alpha=1.82, radius and temperature at the bottom of the convective envelope are R(bottom)=0.724 Rsun and T(bottom)=2.14E6 K, respectively.

M. Yildiz; N. Kiziloglu

1997-06-23T23:59:59.000Z

392

High explosive systems for equation-of-state studies  

Science Conference Proceedings (OSTI)

Experimental and calculational studies were made to specify a suite of explosive impactor systems to be used in high pressure equation-of-state (EOS) measurements. 316 stainless steel (SS) was used as the driver or impactor. The investigation included some systems where the high explosive (HE) driving the plate to be used as the impactor was preshocked by another thicker SS plate. The effect of lateral confinement, either by HE or iron rings constituted part of the study. The effect of separating the HE and driver was also studied. The velocity range encompassed was from less than 4 km/s to over 9 km/s, which was observed in a two-stage experiment. 4 figs., 1 tab.

McQueen, R.G.; Marsh, S.P.

1987-01-01T23:59:59.000Z

393

Adsorption of a fluid in an aerogel: integral equation approach  

E-Print Network (OSTI)

We present a theoretical study of the phase diagram and the structure of a fluid adsorbed in high-porosity aerogels by means of an integral-equation approach combined with the replica formalism. To simulate a realistic gel environment, we use an aerogel structure factor obtained from an off-lattice diffusion-limited cluster-cluster aggregation process. The predictions of the theory are in qualitative agreement with the experimental results, showing a substantial narrowing of the gas-liquid coexistence curve (compared to that of the bulk fluid), associated with weak changes in the critical density and temperature. The influence of the aerogel structure (nontrivial short-range correlations due to connectedness, long-range fractal behavior of the silica strands) is shown to be important at low fluid densities. I.

V. Krakoviack; E. Kierlik; M. -l. Rosinberg; G. Tarjus

2008-01-01T23:59:59.000Z

394

Central equation of state in spherical characteristic evolutions  

Science Conference Proceedings (OSTI)

We study the evolution of a perfect-fluid sphere coupled to a scalar radiation field. By ensuring a Ricci invariant regularity as a conformally flat spacetime at the central world line we find that the fluid coupled to the scalar field satisfies the equation of state {rho}{sub c}+3p{sub c}=const at the center of the sphere, where the energy {rho}{sub c} density and the pressure p{sub c} do not necessarily contain the scalar field contribution. The fluid can be interpreted as anisotropic and radiant because of the scalar field, but it becomes perfect and nonradiative at the center of the sphere. These results are currently being considered to build up a numerical relativistic hydrodynamic solver.

Barreto, W.; Castillo, L.; Barrios, E. [Centro de Fisica Fundamental, Facultad de Ciencias, Universidad de Los Andes, Merida 5101, Estado Merida (Venezuela, Bolivarian Republic of); Departamento de Fisica, Escuela de Ciencias, Nucleo de Sucre, Universidad de Oriente, Cumana 6101, Estado Sucre (Venezuela, Bolivarian Republic of); Postgrado en Fisica Fundamental, Facultad de Ciencias, Universidad de Los Andes, Merida 5101, Estado Merida (Venezuela, Bolivarian Republic of)

2009-10-15T23:59:59.000Z

395

Stochastic Integrals and Evolution Equations with Gaussian Random Fields  

SciTech Connect

The paper studies stochastic integration with respect to Gaussian processes and fields. It is more convenient to work with a field than a process: by definition, a field is a collection of stochastic integrals for a class of deterministic integrands. The problem is then to extend the definition to random integrands. An orthogonal decomposition of the chaos space of the random field, combined with the Wick product, leads to the Ito-Skorokhod integral, and provides an efficient tool to study the integral, both analytically and numerically. For a Gaussian process, a natural definition of the integral follows from a canonical correspondence between random processes and a special class of random fields. Also considered are the corresponding linear stochastic evolution equations.

Lototsky, S.V., E-mail: lototsky@math.usc.edu; Stemmann, K. [USC, Department of Mathematics (United States)], E-mail: stemmann@usc.edu

2009-04-15T23:59:59.000Z

396

Optimal Control of a Parabolic Equation with Dynamic Boundary Condition  

SciTech Connect

We investigate a control problem for the heat equation. The goal is to find an optimal heat transfer coefficient in the dynamic boundary condition such that a desired temperature distribution at the boundary is adhered. To this end we consider a function space setting in which the heat flux across the boundary is forced to be an L{sup p} function with respect to the surface measure, which in turn implies higher regularity for the time derivative of temperature. We show that the corresponding elliptic operator generates a strongly continuous semigroup of contractions and apply the concept of maximal parabolic regularity. This allows to show the existence of an optimal control and the derivation of necessary and sufficient optimality conditions.

Hoemberg, D., E-mail: hoemberg@wias-berlin.de; Krumbiegel, K., E-mail: krumbieg@wias-berlin.de [Weierstrass Institute for Applied Mathematics and Stochastics, Nonlinear Optimization and Inverse Problems (Germany); Rehberg, J., E-mail: rehberg@wias-berlin.de [Weierstrass Institute for Applied Mathematics and Stochastics, Partial Differential Equations (Germany)

2013-02-15T23:59:59.000Z

397

Thermodynamics of apparent horizon and modified Friedman equations  

E-Print Network (OSTI)

Starting from the first law of thermodynamics, $dE=T_hdS_h+WdV$, at apparent horizon of a FRW universe, and assuming that the associated entropy with apparent horizon has a quantum corrected relation, $S=\\frac{A}{4G}-\\alpha \\ln \\frac{A}{4G}+\\beta \\frac{4G}{A}$, we derive modified Friedmann equations describing the dynamics of the universe with any spatial curvature. We also examine the time evolution of the total entropy including the quantum corrected entropy associated with the apparent horizon together with the matter field entropy inside the apparent horizon. Our study shows that, with the local equilibrium assumption, the generalized second law of thermodynamics is fulfilled in a region enclosed by the apparent horizon.

Ahmad Sheykhi

2010-12-02T23:59:59.000Z

398

The reduced basis method for the electric field integral equation  

Science Conference Proceedings (OSTI)

We introduce the reduced basis method (RBM) as an efficient tool for parametrized scattering problems in computational electromagnetics for problems where field solutions are computed using a standard Boundary Element Method (BEM) for the parametrized electric field integral equation (EFIE). This combination enables an algorithmic cooperation which results in a two step procedure. The first step consists of a computationally intense assembling of the reduced basis, that needs to be effected only once. In the second step, we compute output functionals of the solution, such as the Radar Cross Section (RCS), independently of the dimension of the discretization space, for many different parameter values in a many-query context at very little cost. Parameters include the wavenumber, the angle of the incident plane wave and its polarization.

Fares, M., E-mail: fares@cerfacs.f [2 Avenue Gaspard Coriolis, 31057 Toulouse Cedex 01 (France); Hesthaven, J.S., E-mail: Jan_Hesthaven@Brown.ed [Division of Applied Mathematics, Brown University, Box F, Providence, RI 02912 (United States); Maday, Y., E-mail: maday@ann.jussieu.f [Laboratoire Jacques-Louis Lions, Universite Pierre et Marie Curie, Boite courrier 18, 75252 Paris Cedex 05 (France); Stamm, B., E-mail: stamm@math.berkeley.ed [Department of Mathematics, University of California, Berkeley, CA 94720 (United States)

2011-06-20T23:59:59.000Z

399

Krylov methods for the incompressible Navier-Stokes equations  

Science Conference Proceedings (OSTI)

Methods are presented for time evolution, steady-state solving and linear stability analysis for the incompressible Navier-Stokes equations at low to moderate Reynolds numbers. The methods use Krylov subspaces constructed by the Arnoldi process from actions of the explicit Navier-Stokes right-hand side and of its Jacobian, without inversion of the viscous operator. Time evolution is performed by a nonlinear extension of the method of exponential propagation. Steady states are calculated by inexact Krylov-Newton iteration using ORTHORES and GMRES. Linear stability analysis is carried out using an implicitly restarted Arnoldi process with implicit polynomial filters. A detailed implementation is described for a pseudospectral calculation of the stability of Taylor vortices with respect to wavy vortices in the Couette-Taylor problems. 61 refs., 10 figs., 1 tab.

Edwards, W.S.; Tuckerman, L.S. (Univ. of Texas, Austin (United States)); Friesner, R.A. (Columbia Univ., New York, NY (United States)); Sorensen, D.C. (Rice Univ., Houston, TX (United States))

1994-01-01T23:59:59.000Z

400

Momentum Scale Expansion of Sharp Cutoff Flow Equations  

E-Print Network (OSTI)

We show how the exact renormalization group for the effective action with a sharp momentum cutoff, may be organised by expanding one-particle irreducible parts in terms of homogeneous functions of momenta of integer degree (Taylor expansions not being possible). A systematic series of approximations -- the $O(p^M)$ approximations -- result from discarding from these parts, all terms of higher than the $M^{\\rm th}$ degree. These approximations preserve a field reparametrization invariance, ensuring that the field's anomalous dimension is unambiguously determined. The lowest order approximation coincides with the local potential approximation to the Wegner-Houghton equations. We discuss the practical difficulties with extending the approximation beyond $O(p^0)$.

Tim R. Morris

1995-08-04T23:59:59.000Z

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401

Co-relation of Variables Involved in the Occurrence of Crane Accidents in U.S. through Logit Modeling.  

E-Print Network (OSTI)

One of the primary reasons of the escalating rates of injuries and fatalities in the construction industry is the ever so complex, dynamic and continually changing nature of construction work. Use of cranes has become imperative to overcome technical challenges, which has lead to escalation of danger on a construction site. Data from OSHA show that crane accidents have increased rapidly from 2000 to 2004. By analyzing the characteristics of all the crane accident inspections, we can better understand the significance of the many variables involved in a crane accident. For this research, data were collected from the U.S. Department of Labor website via the OSHA database. The data encompass crane accident inspections for all the states. The data were divided into categories with respect to accident types, construction operations, degree of accident, fault, contributing factors, crane types, victim’s occupation, organs affected and load. Descriptive analysis was performed to compliment the previous studies, the only difference being that both fatal and non-fatal accidents have been considered. Multinomial regression has been applied to derive probability models and correlation between different accident types and the factors involved for each crane accident type. A log likelihood test as well as chi-square test was performed to validate the models. The results show that electrocution, crane tip over and crushed during assembly/disassembly have more probability of occurrence than other accident types. Load is not a significant factor for the crane accidents, and manual fault is more probable a cause for crane accident than is technical fault. Construction operations identified in the research were found to be significant for all the crane accident types. Mobile crawler crane, mobile truck crane and tower crane were found to be more susceptible. These probability models are limited as far as the inculcation of unforeseen variables in construction accidents are concerned. In fact, these models utilize the past to portray the future, and therefore significant change in the variables involved is required to be added to attain correct and expedient results.

Bains, Amrit Anoop Singh

2010-08-01T23:59:59.000Z

402

Multi-symplectic relative equilibria, multi-phase wavetrains and coupled NLS equations  

E-Print Network (OSTI)

The paper begins with a geometric formulation of 2-phase wavetrain solutions of coupled nonlinear Schrodinger equations. It is shown that these solutions come in natural 4-parameter families, associated with symmetry, and a geometric instability condition can be deduced from the parameter structure which generalizes Roskes' instability criterion. It is then shown that this geometric structure is universal in the sense that it does not depend on the particular equation, only on the structure of the equations. The theory also extends to the case without symmetry, where small divisors may be present, but gives a new formal geometric framework for multi-phase wavetrains. 1 Introduction This paper has three interrelated parts. It starts by considering a system of coupled nonlinear Schrodinger (cNLS) equations as motivation. Coupled NLS equations are model PDEs which appear in a wide range of wave phenomena, including plasma physics, optics and water waves. The cNLS equations have a basic...

Thomas J. Bridges; Fiona E. Laine-pearson

2000-01-01T23:59:59.000Z

403

Generalized Forchheimer Equation for Two-Phase Flow Based on Hybrid Mixture Theory  

E-Print Network (OSTI)

In this paper, we derive a Forchheimer-type equation for two-phase flow through an isotropic porous medium using hybrid mixture theory. Hybrid mixture theory consists of classical mixture theory applied to a multiphase system with volume averaged equations. It applies to media in which the characteristic length of each phase is "small" relative to the extent of the mixture. The derivation of a Forchheimer equation for single phase flow has been obtained elsewhere. These results are extended to include multiphase swelling materials which have non-negligible interfacial thermodynamic properties. Key words. Porous media, swelling porous media, high velocity flow, non-Darcy flow, two-phase flow, multi-phase flow, mixture theory, Forchheimer equation. 1 Introduction Darcy-type equations are used to describe the flow of a single-phase fluid through porous media in a number of situations. The classical Darcy equation, first derived experimentally in 1856, states that the flux is pro...

Lynn Schreyer Bennethum; Tizian Giorgi

1996-01-01T23:59:59.000Z

404

Comparative study of eight equations of state for predicting hydrocarbon volumetric phase behavior  

Science Conference Proceedings (OSTI)

The objective of this study is to present a review of eight equations of state and compare their ability to predict the volumetric and phase equilibria of gas condensate systems. Included in the study are the Peng-Robinson, the Soave-Redlich-Kwong, the Schmidt-Wenzel, the Usdin-McAuliffe, the Heyen, the Kubic, the Adachi-Lu, and the Patel-Teja equations of state. The Schmidt and Wenzel equation exhibits a superior predictive capability for volumetric properties of condensate systems. The Peng-Robinson equation is found to accurately represent the phase equilibrium behavior of condensate systems. In terms of compressibiity factors, the Schmidt-Wenzel and Patel-Teja equations give better predictions than other equations.

Ahmed, T.H.

1986-01-01T23:59:59.000Z

405

A generalized lens equation for light deflection in weak gravitational fields  

E-Print Network (OSTI)

A generalized lens equation for weak gravitational fields in Schwarzschild metric and valid for finite distances of source and observer from the light deflecting body is suggested. The magnitude of neglected terms in the generalized lens equation is estimated to be smaller than or equal to 15 Pi/4 (m/d')^2, where m is the Schwarzschild radius of massive body and d' is Chandrasekhar's impact parameter. The main applications of this generalized lens equation are extreme astrometrical configurations, where 'Standard post-Newtonian approach' as well as 'Classical lens equation' cannot be applied. It is shown that in the appropriate limits the proposed lens equation yields the known post-Newtonian terms, 'enhanced' post-post-Newtonian terms and the Classical lens equation, thus provides a link between these both essential approaches for determining the light deflection.

Sven Zschocke

2011-05-18T23:59:59.000Z

406

Iterative solutions to large sparse finite element equations  

E-Print Network (OSTI)

Iterative methods are widely used to solve sparse linear systems due to the improvements which can be achieved in reducing the solution time and increasing the size of the problem which can be solved on a given computer compared to traditional direct solvers. The theory behind the convergence rate relationship and storage requirements for the preconditioned conjugate gradient methods using the diagonal scaling, incomplete Cholesky decomposition and SSOR preconditioners is explained in detail in this study. Sparse matrix storage techniques, such as profile, element-by-element, and compact row storage, are described along with the redefined matrix operations for each storage technique which must be used to eliminate the operations on zero elements. A procedure to directly assemble the global stiffness in compact row storage format from element stiffness matrices is introduced. Numerical studies have been performed to compare the storage requirements, the convergence rate, and the solution time for the direct and PCG methods using various storage formats. Effects of different material properties and external loading on the convergence rate and solution time are also analyzed. The test problems for this study are based on the three-dimensional linear elasticity finite element equations. The physical memory of 64 MB of RAM of the IBM RISC/6000 Model 355 workstation was the limiting factor for the size of the sparse linear system that could be solved in this study. The diagonal preconditioned conjugate gradient method with the compact row storage has solved a three-dimensional finite element problem up to a maximum of 50,000 equations on an IBM RISC/6000 Model 355 workstation with 64 MB of RAM. To apply adaptive mesh refinement on certain regions of a coarse mesh, the modeling error over a coarse mesh must be estimated. This thesis will show that the modeling error from an intermediate unconverged coarse mesh solution will closely match the modeling error from the converged solution. This result may lead to quicker solution times for a highly accurate mesh based on adaptive mesh refinement iterative methods.

Wang, Hongbing

1995-01-01T23:59:59.000Z

407

Lattice Boltzmann equation simulations of turbulence, mixing, and combustion  

E-Print Network (OSTI)

We explore the capability of lattice Boltzmann equation (LBE) method for complex fluid flows involving turbulence, mixing, and reaction. In the first study, LBE schemes for binary scalar mixing and multi-component reacting flow with reactions are developed. Simulations of initially non-premixed mixtures yield scalar probability distribution functions that are in good agreement with numerical data obtained from Navier-Stokes (NS) equation based computation. One-dimensional chemically-reacting flow simulation of a premixed mixture yields a flame speed that is consistent with experimentally determined value. The second study involves direct numerical simulation (DNS) and large-eddy simulation (LES) of decaying homogenous isotropic turbulence (HIT) with and without frame rotation. Three categories of simulations are performed: (i) LBE-DNS in both inertial and rotating frames; (ii) LBE-LES in inertial frame; (iii) Comparison of the LBE-LES vs. NS-LES. The LBE-DNS results of the decay exponents for kinetic energy k and dissipation rate ?, and the low wave-number scaling of the energy spectrum agree well with established classical results. The LBE-DNS also captures rotating turbulence physics. The LBE-LES accurately captures low-wave number scaling, energy decay and large scale structures. The comparisons indicate that the LBE-LES simulations preserve flow structures somewhat more accurately than the NS-LES counterpart. In the third study, we numerically investigate the near-field mixing features in low aspect-ratio (AR) rectangular turbulent jets (RTJ) using the LBE method. We use D3Q19 multiple-relaxation-time (MRT) LBE incorporating a subgrid Smagorinsky model for LES. Simulations of four jets which characterized by AR, exit velocity, and Reynolds number are performed. The investigated near-field behaviors include: (1) Decay of mean streamwise velocity (MSV) and inverse MSV; (2) Spanwise and lateral profiles of MSV; (3) Half-velocity width development and MSV contours; and (4) Streamwise turbulence intensity distribution and spanwise profiles of streamwise turbulence intensity. The computations are compared against experimental data and the agreement is good. We capture both unique features of RTJ: the saddle-back spanwise profile of MSV and axis-switching of long axis from spanwise to lateral direction. Overall, this work serves to establish the feasibility of the LBE method as a viable tool for computing mixing, combustion, and turbulence.

Yu, Huidan

2004-12-01T23:59:59.000Z

408

New Kinetic Equations and Bogolyubov Energy Spectrum in a Fermi Quantum Plasma  

SciTech Connect

New type of quantum kinetic equations of the Fermi particles are derived. The Bogolyubov's type of dispersion relation, which is valid for the Bose fluid, is disclosed. Model of neutral Bose atoms in dense strongly coupled plasmas with attractive interaction is discussed. A set of fluid equations describing the quantum plasmas is obtained. Furthermore, the equation of the internal energy of degenerate Fermi plasma particles is derived.

Tsintsadze, Nodar L. [Department of Plasma Physics, E. Andronikashvili Institute of Physics, Tbilisi (Georgia); Tsintsadze, Levan N. [Graduate School of Science, Hiroshima University, Higashi-Hiroshima (Japan)

2009-10-08T23:59:59.000Z

409

Uniqueness of solutions for elliptic systems and fourth order equations involving a parameter  

E-Print Network (OSTI)

We examine the equation \\[\\Delta^2 u = \\lambda f(u) \\qquad \\Omega, \\] with either Navier or Dirichlet boundary conditions. We show some uniqueness results under certain constraints on the parameter $ \\lambda$. We obtain similar results for the sytem {equation*} \\{{array}{rrl} -\\Delta u &=& \\lambda f(v) \\qquad \\Omega, -\\Delta v &=& \\gamma g(u) \\qquad \\Omega, u&=& v = 0 \\qquad \\partial Omega. {array}. {equation*}

Cowan, Craig

2011-01-01T23:59:59.000Z

410

Stability in terms of two measures for a class of semilinear impulsive parabolic equations  

SciTech Connect

The problem of stability in terms of two measures is considered for semilinear impulsive parabolic equations. A new version of the comparison method is proposed, and sufficient conditions for stability in terms of two measures are obtained on this basis. An example of a hybrid impulsive system formed by a system of ordinary differential equations coupled with a partial differential equation of parabolic type is given. The efficiency of the described approaches is demonstrated. Bibliography: 24 titles.

Dvirnyj, Aleksandr I; Slyn'ko, Vitalij I

2013-04-30T23:59:59.000Z

411

Schwarzschild Solution of the Generally Covariant Quaternionic Field Equations of Sachs  

E-Print Network (OSTI)

Sachs has derived quaternion field equations that fully exploit the underlying symmetry of the principle of general relativity, one in which the fundamental 10 component metric field is replaced by a 16 component four-vector quaternion. Instead of the 10 field equations of Einstein's tensor formulation, these equations are 16 in number corresponding to the 16 analytic parametric functions {\\partial}x^{{\\mu}'}/{\\partial}x^{{\

Horace W. Crater; Jesse Labello; Steve Rubenstein

2010-10-18T23:59:59.000Z

412

On the balance equations for a dilute binary mixture in special relativity  

Science Conference Proceedings (OSTI)

In this work we study the properties of a relativistic mixture of two non-reacting species in thermal local equilibrium. We use the full Boltzmann equation (BE) to find the general balance equations. Following conventional ideas in kinetic theory, we use the concept of chaotic velocity. This is a novel approach to the problem. The resulting equations will be the starting point of the calculation exhibiting the correct thermodynamic forces and the corresponding fluxes; these results will be published elsewhere.

Moratto, Valdemar [Departamento de Fisica, Universidad Autonoma Metropolitana-Iztapalapa, Mexico D.F. (Mexico); Garcia-Perciante, A. L. [Departamento de Matematicas Aplicadas y Sistemas, Universidad Autonoma Metropolitana-Cuajimalpa, Mexico D.F. (Mexico); Garcia-Colin, L. S. [Departamento de Fisica, Universidad Autonoma Metropolitana-Iztapalapa, Mexico D.F. (Mexico); El Colegio Nacional, Mexico D.F. (Mexico)

2010-12-14T23:59:59.000Z

413

Equation of State in Relativistic Magnetohydrodynamics: variable versus constant adiabatic index  

E-Print Network (OSTI)

The role of the equation of state for a perfectly conducting, relativistic magnetized fluid is the main subject of this work. The ideal constant $\\Gamma$-law equation of state, commonly adopted in a wide range of astrophysical applications, is compared with a more realistic equation of state that better approximates the single-specie relativistic gas. The paper focus on three different topics. First, the influence of a more realistic equation of state on the propagation of fast magneto-sonic shocks is investigated. This calls into question the validity of the constant $\\Gamma$-law equation of state in problems where the temperature of the gas substantially changes across hydromagnetic waves. Second, we present a new inversion scheme to recover primitive variables (such as rest-mass density and pressure) from conservative ones that allows for a general equation of state and avoids catastrophic numerical cancellations in the non-relativistic and ultrarelativistic limits. Finally, selected numerical tests of astrophysical relevance (including magnetized accretion flows around Kerr black holes) are compared using different equations of state. Our main conclusion is that the choice of a realistic equation of state can considerably bear upon the solution when transitions from cold to hot gas (or viceversa) are present. Under these circumstances, a polytropic equation of state can significantly endanger the solution.

A. Mignone; Jonathan C. McKinney

2007-04-13T23:59:59.000Z

414

A Method for Constructing a Lax Pair for the Ernst Equation  

E-Print Network (OSTI)

A systematic construction of a Lax pair and an infinite set of conservation laws for the Ernst equation is described. The matrix form of this equation is rewritten as a differential ideal of gl(2,R)-valued differential forms, and its symmetry condition is expressed as an exterior equation which is linear in the symmetry characteristic and has the form of a conservation law. By means of a recursive process, an infinite collection of such laws is then obtained, and the conserved "charges" are used to derive a linear exterior equation whose components constitute a Lax pair.

C. J. Papachristou; B. Kent Harrison

2008-05-09T23:59:59.000Z

415

On the relation between the Einstein field equations and the Jacobi-Ricci-Bianchi system  

E-Print Network (OSTI)

The 1+3 covariant equations, embedded in an extended tetrad formalism and describing a space-time with an arbitrary energy-momentum distribution, are reconsidered. It is shown that, provided the 1+3 splitting is performed with respect to a generic timelike congruence with tangent vector u, the Einstein field equations can be regarded as the integrability conditions for the Jacobi and Bianchi equations together with the Ricci equations for u. The same conclusion holds for a generic null congruence in the Newman-Penrose framework.

Norbert Van den Bergh

2013-02-26T23:59:59.000Z

416

Generalized Lorentz-Dirac Equation for a Strongly Coupled Gauge Theory  

SciTech Connect

We derive a semiclassical equation of motion for a 'composite' quark in strongly coupled large-N{sub c} N=4 super Yang-Mills theory, making use of the anti-de Sitter space/conformal field theory correspondence. The resulting nonlinear equation incorporates radiation damping, and reduces to the standard Lorentz-Dirac equation for external forces that are small on the scale of the quark Compton wavelength, but has no self-accelerating or preaccelerating solutions. From this equation one can read off a nonstandard dispersion relation for the quark, as well as a Lorentz-covariant formula for its radiation rate.

Chernicoff, Mariano; Garcia, J. Antonio; Gueijosa, Alberto [Departamento de Fisica de Altas Energias, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, Mexico Distrito Federal 04510 (Mexico)

2009-06-19T23:59:59.000Z

417

A branch-point approximant for the equation of state of hard spheres  

E-Print Network (OSTI)

Using the first seven known virial coefficients and forcing it to possess two branch-point singularities, a new equation of state for the hard-sphere fluid is proposed. This equation of state predicts accurate values of the higher virial coefficients, a radius of convergence smaller than the close-packing value, and it is as accurate as the rescaled virial expansion and better than the Pad\\'e [3/3] equations of state. Consequences regarding the convergence properties of the virial series and the use of similar equations of state for hard-core fluids in $d$ dimensions are also pointed out.

Andrés Santos; Mariano López de Haro

2009-03-23T23:59:59.000Z

418

New Improved Equations For Na-K, Na-Li And Sio2 Geothermometers...  

Open Energy Info (EERE)

Improved Equations For Na-K, Na-Li And Sio2 Geothermometers By Outlier Detection And Rejection Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: New...

419

Conjugate Spinor Solution of the Dirac Equation for the Hydrogen Atom  

E-Print Network (OSTI)

It is shown the central field Dirac equation can be simplified through the use of real conjugate spinors to substitute for the upper and lower components of the bi-spinor eigensolutions. This substitution reduces the Dirac equation for the hydrogen atom to the problem of solving a single second order differential equation similar to a Klein-Gordon equation but containing additional terms to take account of the spin on the electron. The bi-spinor wave functions are readily constructed once the solution is known in terms of the conjugate spinors.

Robert J. Ducharme

2011-04-18T23:59:59.000Z

420

CORTICAL PHASE TRANSITIONS, NONEQUILIBRIUM THERMODYNAMICS AND THE TIME-DEPENDENT GINZBURG LANDAU EQUATION  

E-Print Network (OSTI)

Nonequilibrium Thermodynamics and Time-Dependent GL EquationNONEQUILIBRIUM THERMODYNAMICS AND THE TIME-DEPENDENTour attention on the thermodynamics of the nonequilibrium

Freeman, Walter J.; Livi, Robert; Obinata, Masashi; Vitiello, Giuseppe

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
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to obtain the most current and comprehensive results.


421

Initial-value problem for a linear ordinary differential equation of noninteger order  

Science Conference Proceedings (OSTI)

An initial-value problem for a linear ordinary differential equation of noninteger order with Riemann-Liouville derivatives is stated and solved. The initial conditions of the problem ensure that (by contrast with the Cauchy problem) it is uniquely solvable for an arbitrary set of parameters specifying the orders of the derivatives involved in the equation; these conditions are necessary for the equation under consideration. The problem is reduced to an integral equation; an explicit representation of the solution in terms of the Wright function is constructed. As a consequence of these results, necessary and sufficient conditions for the solvability of the Cauchy problem are obtained. Bibliography: 7 titles.

Pskhu, Arsen V [Scientific Research Institute of Applied Mathematics and Automation, Kabardino-Balkar Scientific Centre of the Russian Academy of Sciences, Nalchik (Russian Federation)

2011-04-30T23:59:59.000Z

422

Exact momentum conservation laws for the gyrokinetic Vlasov-Poisson equations  

Science Conference Proceedings (OSTI)

The exact momentum conservation laws for the nonlinear gyrokinetic Vlasov-Poisson equations are derived by applying the Noether method on the gyrokinetic variational principle [A. J. Brizard, Phys. Plasmas 7, 4816 (2000)]. From the gyrokinetic Noether canonical-momentum equation derived by the Noether method, the gyrokinetic parallel momentum equation and other gyrokinetic Vlasov-moment equations are obtained. In addition, an exact gyrokinetic toroidal angular-momentum conservation law is derived in axisymmetric tokamak geometry, where the transport of parallel-toroidal momentum is related to the radial gyrocenter polarization, which includes contributions from the guiding-center and gyrocenter transformations.

Brizard, Alain J. [Department of Chemistry and Physics, Saint Michael's College, Colchester, Vermont 05439 (United States); Tronko, Natalia [Centre de Physique Theorique, Campus de Luminy, Case 907, 13288 Marseille cedex 9 (France); Centre for Fusion, Space and Astrophysics, Department of Physics, University of Warwick, Coventry CV4 7AL (United Kingdom)

2011-08-15T23:59:59.000Z

423

A New Look at the Airy Equation with Fences and Funnels - CECM  

E-Print Network (OSTI)

For example, the differential equation yields power series solutions that represent ... The Riccati transformation describes the evolution of the slope of the line ...

424

On inverse scattering at high energies for the multidimensional Newton equation in electromagnetic field  

E-Print Network (OSTI)

We consider the multidimensional (nonrelativistic) Newton equation in a static electromagnetic field $$\\ddot x = F(x,\\dot x), F(x,\\dot x)=-\

Alexandre Jollivet

2007-09-29T23:59:59.000Z

425

Concerning the equation of state for partially ionized system  

DOE Green Energy (OSTI)

I will discuss the expansion of various thermodynamic quantities about the ideal gas in powers of the electric charge, and I will discuss some cellular models. The first type of cellular model is appropriate for hydrogen. The second type is for Z > 1. It has the independent electron approximation within the atoms. These models are cross compared and minimal regions of validity are determined. The actual region of validity is expected to be larger. In the cellular models, the phase boundaries for liquid-gas transitions are found. For the second type of cellular model, in the part of the low-temperature, low-density region where there is not much expectation of validity of these methods, a non-thermodynamic region is found. I have devised a construction, similar in spirit to the Maxwell construction, to bridge this region so as to leave a thermodynamically valid equation of state. The non-thermodynamic region does not occur in hydrogen and it seems to be due to the inadequacy of the aforementioned approximation in that region.

Baker, Jr, George A [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

426

Modern integral equation techniques for quantum reactive scattering theory  

SciTech Connect

Rigorous calculations of cross sections and rate constants for elementary gas phase chemical reactions are performed for comparison with experiment, to ensure that our picture of the chemical reaction is complete. We focus on the H/D+H{sub 2} {yields} H{sub 2}/DH + H reaction, and use the time independent integral equation technique in quantum reactive scattering theory. We examine the sensitivity of H+H{sub 2} state resolved integral cross sections {sigma}{sub v{prime}j{prime},vj}(E) for the transitions (v = 0,j = 0) to (v{prime} = 1,j{prime} = 1,3), to the difference between the Liu-Siegbahn-Truhlar-Horowitz (LSTH) and double many body expansion (DMBE) ab initio potential energy surfaces (PES). This sensitivity analysis is performed to determine the origin of a large discrepancy between experimental cross sections with sharply peaked energy dependence and theoretical ones with smooth energy dependence. We find that the LSTH and DMBE PESs give virtually identical cross sections, which lends credence to the theoretical energy dependence.

Auerbach, S.M.

1993-11-01T23:59:59.000Z

427

Massless Dirac equation as a special case of Cosserat elasticity  

E-Print Network (OSTI)

We suggest an alternative mathematical model for the massless neutrino. Consider an elastic continuum in 3-dimensional Euclidean space and assume that points of this continuum can experience no displacements, only rotations. This framework is a special case of the so-called Cosserat theory of elasticity. Rotations of points of the continuum are described by attaching to each point an orthonormal basis which gives a field of orthonormal bases called the coframe. As the dynamical variables (unknowns) of our theory we choose a coframe and a density. We write down a potential energy which is conformally invariant and then incorporate time in the standard Newtonian way, by subtracting kinetic energy. Finally, we rewrite the resulting nonlinear variational problem in terms of an unknown spinor field. We look for quasi-stationary solutions, i.e. solutions that harmonically oscillate in time. We prove that in the quasi-stationary setting our model is equivalent to a pair of massless Dirac equations. The crucial element of the proof is the observation that our Lagrangian admits a factorisation.

Olga Chervova; Dmitri Vassiliev

2009-02-07T23:59:59.000Z

428

Nuclear Density Functional Theory and the Equation of State  

E-Print Network (OSTI)

A nuclear density functional can be used to find the binding energy and shell structure of nuclei and the energy gap in superconducting nuclear matter. In this paper, we study the possible application of a nuclear density functional theory to nuclear astrophysics. From energy density functional theory, we can deduce the interaction between nucleons to find a rough estimate of the charge radius of the specific nuclei. Compared to the Finite-Range Thomas Fermi model, we include three-body forces, which might be important at densities several times that of nuclear matter density. We also add the momentum dependent interaction to take into account the effective mass of the nucleons. We study matter in the neutron star crust using the Wigner-Seitz cell method. By constructing the mass-radius relation of neutron stars and investigating lepton-rich nuclear matter in proto-neutron stars, we find that the density functional can be used to construct an equation of state of hot dense matter.

Yeunhwan Lim

2011-04-06T23:59:59.000Z

429

Nuclear Density Functional Theory and the Equation of State  

E-Print Network (OSTI)

A nuclear density functional can be used to find the binding energy and shell structure of nuclei and the energy gap in superconducting nuclear matter. In this paper, we study the possible application of a nuclear density functional theory to nuclear astrophysics. From energy density functional theory, we can deduce the interaction between nucleons to find a rough estimate of the charge radius of the specific nuclei. Compared to the Finite-Range Thomas Fermi model, we include three-body forces, which might be important at densities several times that of nuclear matter density. We also add the momentum dependent interaction to take into account the effective mass of the nucleons. We study matter in the neutron star crust using the Wigner-Seitz cell method. By constructing the mass-radius relation of neutron stars and investigating lepton-rich nuclear matter in proto-neutron stars, we find that the density functional can be used to construct an equation of state of hot dense matter.

Lim, Yeunhwan

2011-01-01T23:59:59.000Z

430

Controlled Nonlinear Stochastic Delay Equations: Part I: Modeling and Approximations  

SciTech Connect

This two-part paper deals with 'foundational' issues that have not been previously considered in the modeling and numerical optimization of nonlinear stochastic delay systems. There are new classes of models, such as those with nonlinear functions of several controls (such as products), each with is own delay, controlled random Poisson measure driving terms, admissions control with delayed retrials, and others. There are two basic and interconnected themes for these models. The first, dealt with in this part, concerns the definition of admissible control. The classical definition of an admissible control as a nonanticipative relaxed control is inadequate for these models and needs to be extended. This is needed for the convergence proofs of numerical approximations for optimal controls as well as to have a well-defined model. It is shown that the new classes of admissible controls do not enlarge the range of the value functions, is closed (together with the associated paths) under weak convergence, and is approximatable by ordinary controls. The second theme, dealt with in Part II, concerns transportation equation representations, and their role in the development of numerical algorithms with much reduced memory and computational requirements.

Kushner, Harold J., E-mail: hjk@dam.brown.edu [Brown University, Applied Math (United States)

2012-08-15T23:59:59.000Z

431

Reformulation of nonlinear integral magnetostatic equations for rapid iterative convergence  

SciTech Connect

The integral equations of magnetostatics, conventionally given in terms of the field variables M and H, are reformulated with M and B. Stability criteria and convergence rates of the eigenvectors of the linear iteration matrices are evaluated. The relaxation factor ..beta.. in the MH approach varies inversely with permeability ..mu.., and nonlinear problems with high permeability converge slowly. In contrast, MB iteration is stable for ..beta.. < 2, and nonlinear problems converge rapidly, at a rate essentially independent of ..mu... For a permeability of 10/sup 3/, the number of iterations is reduced by two orders of magnitude over the conventional method, and at higher permeabilities the reduction is proportionally greater. The dependence of MB convergence rate on ..beta.., degree of saturation, element aspect ratio, and problem size is found numerically. An analytical result for the MB convergence rate for small nonlinear problems is found to be accurate for ..beta..less than or equal to1.2. The results are generally valid for two- and three-dimensional integral methods and are independent of the particular discretization procedures used to compute the field matrix.

Bloomberg, D.S.; Castelli, V.

1985-03-01T23:59:59.000Z

432

Test plan for validation of the radiative transfer equation.  

SciTech Connect

As the capabilities of numerical simulations increase, decision makers are increasingly relying upon simulations rather than experiments to assess risks across a wide variety of accident scenarios including fires. There are still, however, many aspects of fires that are either not well understood or are difficult to treat from first principles due to the computational expense. For a simulation to be truly predictive and to provide decision makers with information which can be reliably used for risk assessment the remaining physical processes must be studied and suitable models developed for the effects of the physics. A set of experiments are outlined in this report which will provide soot volume fraction/temperature data and heat flux (intensity) data for the validation of models for the radiative transfer equation. In addition, a complete set of boundary condition measurements will be taken to allow full fire predictions for validation of the entire fire model. The experiments will be performed with a lightly-sooting liquid hydrocarbon fuel fire in the fully turbulent scale range (2 m diameter).

Ricks, Allen Joseph; Grasser, Thomas W.; Kearney, Sean Patrick; Jernigan, Dann A.; Blanchat, Thomas K.

2010-09-01T23:59:59.000Z

433

Post-Newtonian gravitational radiation and equations of motion via direct integration of the relaxed Einstein equations. III. Radiation reaction for binary systems with spinning bodies  

E-Print Network (OSTI)

Using post-Newtonian equations of motion for fluid bodies that include radiation-reaction terms at 2.5 and 3.5 post-Newtonian (PN) order (O[(v/c)^5] and O[(v/c)^7] beyond Newtonian order), we derive the equations of motion for binary systems with spinning bodies. In particular we determine the effects of radiation-reaction coupled to spin-orbit effects on the two-body equations of motion, and on the evolution of the spins. For a suitable definition of spin, we reproduce the standard equations of motion and spin-precession at the first post-Newtonian order. At 3.5PN order, we determine the spin-orbit induced reaction effects on the orbital motion, but we find that radiation damping has no effect on either the magnitude or the direction of the spins. Using the equations of motion, we find that the loss of total energy and total angular momentum induced by spin-orbit effects precisely balances the radiative flux of those quantities calculated by Kidder et al. The equations of motion may be useful for evolving inspiraling orbits of compact spinning binaries.

Clifford M. Will

2005-02-09T23:59:59.000Z

434

Wormholes with a space- and time-dependent equation of state  

E-Print Network (OSTI)

The discovery that the Universe is undergoing an accelerated expansion has suggested the existence of an evolving equation of state. This paper discusses various wormhole solutions in a spherically symmetric spacetime with an equation of state that is both space and time dependent. The solutions obtained are exact and generalize earlier results on static wormholes supported by phantom energy.

Peter K. F. Kuhfittig

2007-07-31T23:59:59.000Z

435

Soliton Kinetic Equations with Non-Kolmogorovian Structure: A New Tool for Biological Modeling?  

E-Print Network (OSTI)

is nonlinear kinetics of a chemical type). Another application is a simple two-qubit system whose evolution-Kolmogorovian aspects of chemical kinetics. Next, we briefly discuss the links between kinetic equations and their Lax equations becomes then especially clear. NON-KOLMOGOROVIAN ASPECTS OF CHEMICAL KINETICS Consider

Aerts, Diederik

436

Generalized Forchheimer Equation for Two-Phase Flow Based on Hybrid Mixture Theory  

Science Conference Proceedings (OSTI)

In this paper, we derive a Forchheimer-type equation for two-phase flow through an isotropic porous medium using hybrid mixture theory. Hybrid mixture theory consists of classical mixture theory applied to a multiphase system with volume averaged equations. ...

Lynn S Bennethum; Tizian Giorgi

1996-11-01T23:59:59.000Z

437

Finite difference schemes for the Schrodinger-Maxwell equations (with a general non-linear term)  

Science Conference Proceedings (OSTI)

In this paper, the Numerical Solution of the system of PDEs of Schrodinger-Maxwell equations (with a general nonlinear term) via an appropriate Finite Difference Scheme is introduced. The Existence and Uniqueness of the discretization of the system of ... Keywords: Schrodinger-Maxwell equations, finite difference, finite difference schemes

Nikos E. Mastorakis

2009-06-01T23:59:59.000Z

438

Approximate Equations of Motion for Compact Spinning Bodies in General Relativity  

E-Print Network (OSTI)

Approximate equations are derived for the motion of a gyroscope on the earth's gravitational field using the Einstein, Infeld, Hoffmann surface integral method. This method does not require a knowledge of the energy-momentum-stress tensor associated with the gyroscope and uses only its exterior field for its characterization. The resulting equations of motion differ from those of previous derivations.

James L. Anderson

2005-11-16T23:59:59.000Z

439

Lyapunov Equations, Energy Functionals, and Model Order Reduction of Bilinear and Stochastic Systems  

Science Conference Proceedings (OSTI)

We discuss the relation of a certain type of generalized Lyapunov equations to Gramians of stochastic and bilinear systems together with the corresponding energy functionals. While Gramians and energy functionals of stochastic linear systems show a strong ... Keywords: Gramians, Lyapunov equations, balanced truncation, bilinear systems, energy functionals, model order reduction, stochastic systems

Peter Benner; Tobias Damm

2011-03-01T23:59:59.000Z

440

Steam generators two phase flows numerical simulation with liquid and gas momentum equations  

E-Print Network (OSTI)

Steam generators two phase flows numerical simulation with liquid and gas momentum equations M dimensional two-phase (liquid and gas) flows. The main goal is to improve the mod- eling of kinetic imbalance between the phases. We present a method that solves the mix- ture (liquid-gas) mass and enthalpy equations

Paris-Sud XI, Université de

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

A box-type scheme for fractional sub-diffusion equation with Neumann boundary conditions  

Science Conference Proceedings (OSTI)

Combining order reduction approach and L1 discretization, a box-type scheme is presented for solving a class of fractional sub-diffusion equation with Neumann boundary conditions. A new inner product and corresponding norm with a Sobolev embedding inequality ... Keywords: Box-type scheme, Convergence, Energy method, Neumann boundary conditions, Stability, Sub-diffusion equation

Xuan Zhao; Zhi-zhong Sun

2011-07-01T23:59:59.000Z

442

A matrix free implicit scheme for solution of resistive magneto-hydrodynamics equations on unstructured grids  

Science Conference Proceedings (OSTI)

The resistive magneto-hydrodynamics (MHD) governing equations represent eight conservation equations for the evolution of density, momentum, energy and induced magnetic fields in an electrically conducting fluid, typically a plasma. A matrix free implicit ... Keywords: Finite volume methods, Implicit schemes, Lower-Upper Symmetric Gauss Seidel, Magneto-hydrodynamics, Matrix-free, Unstructured grids

H. Sitaraman, L. L. Raja

2013-10-01T23:59:59.000Z

443

Fourth-order alternating direction implicit compact finite difference schemes for two-dimensional Schrödinger equations  

Science Conference Proceedings (OSTI)

In this paper, alternating direction implicit compact finite difference schemes are devised for the numerical solution of two-dimensional Schrodinger equations. The convergence rates of the present schemes are of order O(h^4+@t^2). Numerical experiments ... Keywords: ADI compact difference scheme, Conservation law, Error estimate, Schrödinger equation

Zhen Gao; Shusen Xie

2011-04-01T23:59:59.000Z

444

A Cartesian grid embedded boundary method for the heat equation on irregular domains  

E-Print Network (OSTI)

A Cartesian Grid Embedded Boundary Method for the Heatheat equation on irregular time-dependent domains. It is based on the Cartesian gridHEAT EQUATION FOR FIXED BOUNDARIES Spatial discretization The underlying discretization of space is given by rectangular control volumes on a Cartesian grid:

McCorquodale, Peter; Colella, Phillip; Johansen, Hans

2001-01-01T23:59:59.000Z

445

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

446

Fluid Mechanics Part 1: General (Mechanical) Energy Equation and other topics  

E-Print Network (OSTI)

Fluid Mechanics Part 1: General (Mechanical) Energy Equation and other topics Dene. By writing down a (mechanical) energy conservation equation for this uid element, we nd that: p + u2 2 + gz.g. by a windmill); loss of mechanical energy from friction. All Eq. (1) really says is that the change

Nimmo, Francis

447

STRSCNE: A Scaled Trust-Region Solver for Constrained Nonlinear Equations  

Science Conference Proceedings (OSTI)

In this paper a Matlab solver for constrained nonlinear equations is presented. The code, called STRSCNE, is based on the affine scaling trust-region method STRN, recently proposed by the authors. The approach taken in implementing the key steps of the ... Keywords: constrained equations, global convergence, performance profile, trust-region methods

Stefania Bellavia; Maria Macconi; Benedetta Morini

2004-04-01T23:59:59.000Z

448

Accurate calculation of Green's function of the Schrödinger equation in a block layered potential  

Science Conference Proceedings (OSTI)

In this paper a new algorithm is presented for calculating the Green's function of the Schrodinger equation in the presence of block layered potentials. Such Green's functions have various and practical applications in quantum modelling of electron transport ... Keywords: 34L10, 81Q05, Block layered media, Eigenfunction expansion, Green's function, Sturm-Liouville problem, The Schrödinger equation

Sihong Shao; Wei Cai; Huazhong Tang

2006-12-01T23:59:59.000Z

449

Smoothness criteria for Navier-Stokes equations in terms of regularity along the steam lines  

E-Print Network (OSTI)

This article is devoted to a regularity criteria for solutions of the Navier-Stokes equations in terms of regularity along the stream lines. More precisely, we prove that a suitable weak solution for the Navier-Stokes equations is regular under some constraint on the second derivative of |u| along the stream lines.

Chan, Chi Hin

2007-01-01T23:59:59.000Z

450

Superconvergence of the local discontinuous Galerkin method for the linearized Korteweg-de Vries equation  

Science Conference Proceedings (OSTI)

We study the superconvergence property of the local discontinuous Galerkin (LDG) method for solving the linearized Korteweg-de Vries (KdV) equation. We prove that, if the piecewise P^k polynomials with k>=1 are used, the LDG solution converges to a particular ... Keywords: Error estimates, Korteweg-de Vries equation, Local discontinuous Galerkin method, Superconvergence

Casey Hufford, Yulong Xing

2014-01-01T23:59:59.000Z

451

A high-order discontinuous Galerkin method for the unsteady incompressible Navier-Stokes equations  

Science Conference Proceedings (OSTI)

We present a high-order discontinuous Galerkin discretization of the unsteady incompressible Navier-Stokes equations in convection-dominated flows using triangular and tetrahedral meshes. The scheme is based on a semi-explicit temporal discretization ... Keywords: Algebraic splitting methods, Discontinuous Galerkin methods, High-order methods, Incompressible flows, Navier-Stokes equations

Khosro Shahbazi; Paul F. Fischer; C. Ross Ethier

2007-03-01T23:59:59.000Z

452

A spectral solution of nonlinear mean field dynamo equations: With inertia  

Science Conference Proceedings (OSTI)

This paper presents a numerical solution method for the nonlinear mean field dynamo equations in a rotating fluid spherical shell. A finite amplitude field drives a flow through the Lorentz force in the momentum equation and this flow feeds back on the ... Keywords: Earth's core, Inertial effect, Mean field dynamo, Spectral method, Spherical shell

Mohammad M. Rahman; David R. Fearn

2009-08-01T23:59:59.000Z

453

Multiplicity of positive solutions for nonlinear field equations in $\\R^{N}$  

E-Print Network (OSTI)

In this paper we study the multiplicity of positive solutions for nonlinear elliptic equations on $\\R^N$. The number of solutions is greater or equal than the number of disjoint intervals on which the nonlinear term is negative. Applications are given to multiplicity of standing waves for the nonlinear Schr\\"odinger, Klein-Gordon and Klein-Gordon-Maxwell equations.

Bonanno, Claudio

2009-01-01T23:59:59.000Z

454

Simulation of laser propagation in a plasma with a frequency wave equation  

Science Conference Proceedings (OSTI)

The aim of this work is to perform numerical simulations of the propagation of a laser beam in a plasma. At each time step, one has to solve a Helmholtz equation with variable coefficients in a domain which may contain more than hundred millions of cells. ... Keywords: cyclic reduction method, domain decomposition method, helmholtz equation, non-hermitian linear solver, separable matrix

R. Sentis; S. Desroziers; F. Nataf

2006-06-01T23:59:59.000Z

455

Parabolic equation solution of seismo-acoustics problems involving variations in bathymetry and sediment thickness  

E-Print Network (OSTI)

Parabolic equation solution of seismo-acoustics problems involving variations in bathymetry September 2007; accepted 27 September 2007 Recent improvements in the parabolic equation method are combined to extend this approach to a larger class of seismo-acoustics problems. The variable rotated parabolic

456

Model Problem for Integro-Differential Zakai Equation with Discontinuous Observation Processes  

SciTech Connect

The existence and uniqueness in Hoelder spaces of solutions of the Cauchy problem to a stochastic parabolic integro-differential equation of the order {alpha}{<=}2 is investigated. The equation considered arises in a filtering problem with a jump signal process and a jump observation process.

Mikulevicius, R., E-mail: mikulvcs@math.usc.edu [University of Southern California (United States); Pragarauskas, H. [Vilnius University, Institute of Mathematics and Informatics (Lithuania)

2011-08-15T23:59:59.000Z

457

AN ABSTRACT APPROACH TO DOMAIN PERTURBATION FOR PARABOLIC EQUATIONS AND PARABOLIC  

E-Print Network (OSTI)

AN ABSTRACT APPROACH TO DOMAIN PERTURBATION FOR PARABOLIC EQUATIONS AND PARABOLIC VARIATIONAL Australia Abstract. We study the behaviour of solutions of linear non-autonomous parabolic equations subject of func- tion spaces for non-autonomous parabolic problems is equivalent to Mosco convergence of function

Sydney, University of

458

A Parallel Scheme of the Split-Step Fourier Transform Method for Solving Parabolic Wave Equation  

Science Conference Proceedings (OSTI)

The split-step Fourier transform method for solving the parabolic wave equation is briefly introduced in this paper. To achieve the acceleration of the calculation process, a parallel scheme based on matrix transpose is proposed. Due to some ingenious ... Keywords: Parabolic Wave Equation, Split-Step Fourier Transform Method, Parallel Computing

Liu Shuai; Li Zhi

2012-10-01T23:59:59.000Z

459

Repeated games for eikonal equations, integral curvature flows and non-linear parabolic  

E-Print Network (OSTI)

Repeated games for eikonal equations, integral curvature flows and non-linear parabolic integro works of Kohn and the second author (2006 and 2009): general fully non-linear parabolic integro- surfaces. For parabolic integro-differential equations, players choose smooth functions on the whole space

Paris-Sud XI, Université de

460

A non-hybrid method for the PDF equations of turbulent flows on unstructured grids  

Science Conference Proceedings (OSTI)

In probability density function (PDF) methods of turbulent flows, the joint PDF of several flow variables is computed by numerically integrating a system of stochastic differential equations for Lagrangian particles. A set of parallel algorithms is proposed ... Keywords: Finite element method, Langevin equation, Monte-Carlo method, Particle tracking, Particle-in-cell method, Probability density function method, Scalar dispersion, Turbulent flow, Unstructured grids

J. Bakosi; P. Franzese; Z. Boybeyi

2008-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "logit fuel-sharing equations" 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

Penalty Methods for the Solution of Discrete HJB Equations—Continuous Control and Obstacle Problems  

Science Conference Proceedings (OSTI)

In this paper, we present a novel penalty approach for the numerical solution of continuously controlled HJB equations and HJB obstacle problems. Our results include estimates of the penalization error for a class of penalty terms, and we show that variations ... Keywords: HJB equation, HJB obstacle problem, min-max problem, numerical solution, penalty method, semismooth Newton method, viscosity solution

J. H. Witte; C. Reisinger

2012-03-01T23:59:59.000Z

462

On a numerical subgrid upscaling algorithm for Stokes-Brinkman equations  

Science Conference Proceedings (OSTI)

This paper discusses a numerical subgrid resolution approach for solving the Stokes-Brinkman system of equations, which is describing coupled flow in plain and in highly porous media. Various scientific and industrial problems are described by this system, ... Keywords: Multiscale problems, Numerical upscaling, Stokes-Brinkman equations, Subgrid approach

O. Iliev; Z. Lakdawala; V. Starikovicius

2013-02-01T23:59:59.000Z

463

Data fitting in partial differential algebraic equations: some academic and industrial applications  

Science Conference Proceedings (OSTI)

The paper introduces a numerical method to estimate parameters in systems of one-dimensional partial differential algebraic equations. Proceeding from given experimental data, i.e., observation times and measurements, the minimum least-squares distance ... Keywords: data fitting, least-squares optimization, method of lines, parameter estimation, partial differential algebraic equations

K. Schittkowski

2004-02-01T23:59:59.000Z

464

Algorithm 741: least-squares solution of a linear, bordered, block-diagonal system of equations  

Science Conference Proceedings (OSTI)

A package of Fortran subroutines is presented for the least-squares solution of a system of overdetermined, full-rank, linear equations with single-bordered block-diagonal structure. This structure allows for a natural sequential processing, one block ... Keywords: bordered block-diagonal equations, least-squares solutions, sparse systems

Richard D. Ray

1995-03-01T23:59:59.000Z

465

Self-similar solutions of the G-equation - analytic description of the flame surface  

E-Print Network (OSTI)

The main feature of the flame kinematics can be desribed with the G-equation. We investigate the solutions of the G-equation with the well-known self-similar Ansatz. The results are discussed and the method how to get self-similar solutions is briefly mentioned.

I. F. Barna

2010-10-27T23:59:59.000Z

466

Conservation laws for the Maxwell-Dirac equations with a dual Ohm's law  

E-Print Network (OSTI)

Using a general theorem on conservation laws for arbitrary differential equations proved by Ibragimov, we have derived conservation laws for Dirac's symmetrized Maxwell-Lorentz equations under the assumption that both the electric and magnetic charges obey linear conductivity laws (dual Ohm's law). We find that this linear system allows for conservation laws which are non-local in time.

Nail H. Ibragimov; Raisa Khamitova; Bo Thidé

2007-03-05T23:59:59.000Z

467

Finding all solutions of separable systems of piecewise-linear equations using integer programming  

Science Conference Proceedings (OSTI)

Finding all solutions of nonlinear or piecewise-linear equations is an important problem which is widely encountered in science and engineering. Various algorithms have been proposed for this problem. However, the implementation of these algorithms are ... Keywords: 65H10, 65H20, 65K05, Finding all solutions, Integer programming, Piecewise-linear equations

Kiyotaka Yamamura; Naoya Tamura

2012-05-01T23:59:59.000Z

468

Coupled force-balance and particle-occupation rate equations for high-field electron transport  

SciTech Connect

It is pointed out that in the framework of balance-equation approach, the coupled force-balance and particle-occupation rate equations can be used as a complete set of equations to determine the high-field transport of semiconductors in both strong and weak electron-electron interaction limits. We call to attention that the occupation rate equation conserves the total particle number and maintains the energy balance of the relative electron system, and there is no need to introduce any other term in it. The addition of an energy-drift term in the particle-occupation rate equation [Phys. Rev. B 71, 195205 (2005)] is physically inadequate for the violation of the total particle-number conservation and the energy balance. It may lead to a substantial unphysical increase of the total particle number by the application of a dc electric field.

Lei, X. L. [Department of Physics, Shanghai Jiaotong University, 1954 Huashan Road, Shanghai 200030 (China)

2008-01-15T23:59:59.000Z

469

Aleksandrov-Bakelman-Pucci Type Estimates For Integro-Differential Equations  

E-Print Network (OSTI)

In this work we provide an Aleksandrov-Bakelman-Pucci type estimate for a certain class of fully nonlinear elliptic integro-differential equations and generalizations of both the Monge-Amp\\`ere operator and the convex envelope to a nonlocal, fractional-order setting. This particular elliptic family under consideration is large enough to capture the second order theory as the order of the integro-differential equations tends to 2. Moreover, our estimate is uniform in the order of the equations, resulting in a genuine generalization of the existing ABP estimate. This result also gives a new comparison theorem for viscosity solutions of such equations which only depends on the $L^\\infty$ and $L^n$ norms of the right hand side, in contrast to previous comparison results which utilize the continuity of the right hand side for their conclusions. These results appear to be new even for the linear case of the relevant equations.

Guillen, Nestor

2011-01-01T23:59:59.000Z

470

Comparative study of eight equations of state for predicting hydrocarbon volumetric phase behavior  

Science Conference Proceedings (OSTI)

The objective of this study is to present a review of eight equations of state (EOS's) and compare their ability to predict the volumetric and phase equilibria of gas-condensate systems. Included in the study are the Peng-Robinson (PR), the Soave-Redlich-Kwong (SRK), the Schmidt-Wenzel (SW), the Usdin-McAuliffe (UM), the Heyen, the Kubic, the Adachi-Lu (AL), and the Patel-Teja (PT) EOS's. The SW equation exhibits a superior predictive capability for volumetric properties of condensate systems. The PR equation is found to represent the phase equilibrium behavior of condensate systems accurately. In terms of compressibility factors, the SW and PT equations give better predictions than other equations.

Ahmed, T.H.

1988-02-01T23:59:59.000Z

471

Core-collapse supernova equations of state based on neutron star observations  

E-Print Network (OSTI)

Many of the currently available equations of state for core-collapse supernova simulations give large neutron star radii and do not provide large enough neutron star masses, both of which are inconsistent with some recent neutron star observations. In addition, one of the critical uncertainties in the nucleon-nucleon interaction, the nuclear symmetry energy, is not fully explored by the currently available equations of state. In this article, we construct two new equations of state which match recent neutron star observations and provide more flexibility in studying the dependence on nuclear matter properties. The equations of state are also provided in tabular form, covering a wide range in density, temperature and asymmetry, suitable for astrophysical simulations. These new equations of state are implemented into our spherically symmetric core-collapse supernova model, which is based on general relativistic radiation hydrodynamics with three-flavor Boltzmann neutrino transport. The results are compared with commonly used equations of state in supernova simulations of 15 and 40 solar mass progenitors. We do not find any simple correlations between individual nuclear matter properties at saturation and the outcome of these simulations. However, the new equations of state lead to the most compact neutron stars among the relativistic mean-field models which we considered. The new models also obey the previously observed correlation between the time to black hole formation and the maximum mass of an s=4 neutron star.

Andrew W. Steiner; Matthias Hempel; Tobias Fischer

2012-07-09T23:59:59.000Z

472

Inline Integration: A new mixed symbolic/numeric approach for solving differential-algebraic equation systems  

E-Print Network (OSTI)

This paper presents a new method for solving di erential{algebraic equation systems using a mixed symbolic and numeric approach. Discretization formulae representing the numerical integration algorithm are symbolically inserted into the di erential{algebraic equation model. The symbolic formulae manipulation algorithm of the model translator treats these additional equations in the same way as it treats the physical equations of the model itself, i.e., it looks at the augmented set of algebraically coupled equations and generates optimized code to be used with the underlying simulation run{time system. For implicit integration methods, a large nonlinear system of equations needs to be solved at every time step. It is shown that the presented uniform treatment of model equations and discretization formulae often leads to a signi cant reduction of the number of iteration variables and therefore to a substantial increase in execution speed. In a large mechatronics system consisting of a six degree{of{freedom robot together with its motors, drive trains, and control systems, this approach led to a speedup factor of more than ten.

Hilding Elmqvist; Martin Otter; Francois E. Cellier

1995-01-01T23:59:59.000Z

473

The linear Fokker-Planck equation for the Ornstein-Uhlenbeck process as an (almost) nonlinear kinetic equation for an isolated N-particle system  

E-Print Network (OSTI)

It is long known that the Fokker-Planck equation with prescribed constant coefficients of diffusion and linear friction describes the ensemble average of the stochastic evolutions in velocity space of a Brownian test particle immersed in a heat bath of fixed temperature. Apparently, it is not so well known that the same partial differential equation, but now with constant coefficients which are functionals of the solution itself rather than being prescribed, describes the kinetic evolution (in the infinite particle limit) of an isolated N-particle system with certain stochastic interactions. Here we discuss in detail this recently discovered interpretation.

Michael Kiessling; Carlo Lancellotti

2005-03-30T23:59:59.000Z

474

Equation of State for Supercooled Water Near the Liquid-Liquid Critical Point  

E-Print Network (OSTI)

We have developed a scaled parametric equation of state to describe and predict thermodynamic properties of supercooled water. The equation of state, built on the growing evidence that the critical point of supercooled liquid-liquid water separation exists, is universal in terms of theoretical scaling fields and is shown to belong to the Ising-model class of universality. The theoretical scaling fields are postulated to be analytical combinations of the physical fields, pressure and temperature. The equation of state enables us to accurately locate the "Widom line" (the locus of stability minima) and determine that the critical pressure is considerably lower than predicted by computer simulations.

M. A. Anisimov; D. A. Fuentevilla

2006-09-19T23:59:59.000Z

475

Surface harmonics method equations for solving the time-dependent neutron transport problems and their verification  

Science Conference Proceedings (OSTI)

Finite-difference time-dependent equations of Surface Harmonics method have been obtained for plane geometry. Verification of these equations has been carried out by calculations of tasks from 'Benchmark Problem Book ANL-7416'. The capacity and efficiency of the Surface Harmonics method have been demonstrated by solution of the time-dependent neutron transport equation in diffusion approximation. The results of studies showed that implementation of Surface Harmonics method for full-scale calculations will lead to a significant progress in the efficient solution of the time-dependent neutron transport problems in nuclear reactors. (authors)

Boyarinov, V. F.; Kondrushin, A. E.; Fomichenko, P. A. [National Research Center, Kurchatov Inst., Kurchatov Sq. 1, Moscow (Russian Federation)

2012-07-01T23:59:59.000Z

476

The form of a constitutive equation of plastic deformation compatible with stress relaxation data  

Science Conference Proceedings (OSTI)

Hart's approach to constitutive equations of plasticity and experimental results relevant to his formalism are reanalyzed, with special emphasis on the consequences of the scaling relation observed in the relaxation curves of a large number of materials. Complete constitutive equations containing a single structure variable are proposed which describe the experimentally determined relaxation and tensile test curves. An interpretation of the structure variable is given in terms of the density of obstacles to dislocations. The equations are generalized to include recovery and applied to dislocation creep.

Fortes, M.A.; Rosa, M.E.

1984-05-01T23:59:59.000Z

477

Spherically symmetric solutions of modified field equations in f(R) theories of gravity  

E-Print Network (OSTI)

Spherically symmetric static empty space solutions are studied in f(R) theories of gravity. We reduce the set of modified Einstein's equations to a single equation and show how one can construct exact solutions in different f(R) models. In particular, we show that for a large class models, including e.g. the f(R)=R-\\mu^4/R model, the Schwarzschild-de Sitter metric is an exact solution of the field equations. The significance of these solutions is discussed in light of solar system constraints on $f(R)$ theories of gravity.

Tuomas Multamaki; Iiro Vilja

2006-06-15T23:59:59.000Z

478

On the iterated Crank-Nicolson for hyperbolic and parabolic equations in numerical relativity  

E-Print Network (OSTI)

The iterated Crank-Nicolson is a predictor-corrector algorithm commonly used in numerical relativity for the solution of both hyperbolic and parabolic partial differential equations. We here extend the recent work on the stability of this scheme for hyperbolic equations by investigating the properties when the average between the predicted and corrected values is made with unequal weights and when the scheme is applied to a parabolic equation. We also propose a variant of the scheme in which the coefficients in the averages are swapped between two corrections leading to systematically larger amplification factors and to a smaller numerical dispersion.

Gregor Leiler; Luciano Rezzolla

2006-01-31T23:59:59.000Z

479

Evolution of Raindrop Spectra. Part I: Solution to the Stochastic Collection/Breakup Equation Using the Method of Moments  

Science Conference Proceedings (OSTI)

We present a solution to the stochastic collection/breakup equation (SCE/SBE) using our recently developed method of moments and the Low and List fragment distribution function. We prove that the collisional breakup equation conserves overall ...

Graham Feingold; Shalvn Tzivion (Tzitzvashvili)Zev Leviv

1988-11-01T23:59:59.000Z

480

On conversion of high-frequency soliton solutions to a (1+1)-dimensional nonlinear evolution equation  

E-Print Network (OSTI)

We derive a (1+1)-dimensional nonlinear evolution equation (NLE) which may model the propagation of high-frequency perturbations in a relaxing medium. As a result, this equation may possess three typical solutions depending on a dissipative parameter.

Kuetche Kamgang Victor; Bouetou Bouetou Thomas; Kofane Timoleon Crepin

2007-09-13T23:59:59.000Z

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481

Using Different Formulations of the Transformed Eulerian Mean Equations and Eliassen–Palm Diagnostics in General Circulation Models  

Science Conference Proceedings (OSTI)

Transformed Eulerian mean (TEM) equations and Eliassen–Palm (EP) flux diagnostics are presented for the general nonhydrostatic, fully compressible, deep atmosphere formulation of the primitive equations in spherical geometric coordinates. The TEM ...

Steven C. Hardiman; David G. Andrews; Andy A. White; Neal Butchart; Ian Edmond

2010-06-01T23:59:59.000Z

482

A four-equation two-phase flow model for sodium boiling simulation of LMFBR fuel assemblies  

E-Print Network (OSTI)

A three-dimensional numerical model for the simulation of sodium boiling transients has been developed. The model uses mixture mass and energy equations, while employing a separate momentum equation for each phase. Thermal ...

Schor, Andrei L.

1982-01-01T23:59:59.000Z

483

Diagnostic Pressure Equation as a Weak Constraint in a Storm-Scale Three-Dimensional Variational Radar Data Assimilation System  

Science Conference Proceedings (OSTI)

A diagnostic pressure equation is incorporated into a storm-scale three-dimensional variational data assimilation (3DVAR) system in the form of a weak constraint in addition to a mass continuity equation constraint (MCEC). The goal of this ...

Guoqing Ge; Jidong Gao; Ming Xue

2012-08-01T23:59:59.000Z

484

A New Method for Solving the Quasi-Geostrophic Omega Equation by Incorporating Surface Pressure Tendency Data  

Science Conference Proceedings (OSTI)

A new method for numerically solving the classical quasi-geostrophic omega equation is proposed. The method, in effect, integrates the omega equation upward using two bottom boundary conditions at the top of the boundary layer: ? and ??/?p. The ...

Peter Zwack; Benoit Okossi

1986-04-01T23:59:59.000Z

485

The Constraints of Energy-Conserving Vertical Finite Difference on the Hydrostatic Equations in a NWP Model  

Science Conference Proceedings (OSTI)

In NWP models using energy-conserving finite-difference approximations in the vertical, the imposition of different constraints of the discrete energy equation leads to different forms of the hydrostatic equation. This paper shows, using the ...

Samuel Y. K. Yee

1983-02-01T23:59:59.000Z

486

Equations Governing Space-Time Variability of Liquid Water Path in Stratus Clouds  

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

Equations Governing Space-Time Variability of Equations Governing Space-Time Variability of Liquid Water Path in Stratus Clouds K. Ivanova Pennsylvania State University University Park, Pennsylvania T. P. Ackerman Pacific Northwest National Laboratory Richland, Washington M. Ausloos University of Liège B-4000 Liège, Belgium Abstract We present a method on how to derive an underlying mathematical (statistical or model free) equation for a liquid water path (LWP) signal directly from empirical data. The evolution of the probability density functions (PDFs) from small to large time scales is explicitly derived in the framework of Fokker-Planck equation. A drift and a diffusion term describing the deterministic and stochastic influences on the non-Gaussian fat tails of the liquid water probability distributions are obtained from

487

On the Sensitivity Equations of Four-Dimensional Variational (4D-Var) Data Assimilation  

Science Conference Proceedings (OSTI)

The equations of the forecast sensitivity to observations and to the background estimate in a four-dimensional variational data assimilation system (4D-Var DAS) are derived from the first-order optimality condition in unconstrained minimization. ...

Dacian N. Daescu

2008-08-01T23:59:59.000Z

488

Some Essential Details for Application of Bleck's Method to the Collision-Breakup Equation  

Science Conference Proceedings (OSTI)

Computational problems have been reported in the literature regarding application of Bleck's method to the collision-breakup equation. It is found that straightforward calculation of the Bleck integrals can involve an inordinate number of ...

Philip S. Brown Jr.

1983-04-01T23:59:59.000Z

489

Is the solution to the BCS gap equation continuous in the temperature ?  

E-Print Network (OSTI)

One of long-standing problems in mathematical studies of superconductivity is to show that the solution to the BCS gap equation is continuous in the temperature. In this paper we address this problem. We regard the BCS gap equation as a nonlinear integral equation on a Banach space consisting of continuous functions of both $T$ and $x$. Here, $T (\\geq 0)$ stands for the temperature and $x$ the kinetic energy of an electron minus the chemical potential. We show that the unique solution to the BCS gap equation obtained in our recent paper is continuous with respect to both $T$ and $x$ when $T$ is small enough. The proof is carried out based on the Banach fixed-point theorem.

Shuji Watanabe

2010-08-26T23:59:59.000Z

490

Numerically Converged Solutions of the Global Primitive Equations for Testing the Dynamical Core of Atmospheric GCMs  

Science Conference Proceedings (OSTI)

Solutions of the dry, adiabatic, primitive equations are computed, for the first time, to numerical convergence. These solutions consist of the short-time evolution of a slightly perturbed, baroclinically unstable, midlatitude jet, initially ...

L. M. Polvani; R. K. Scott; S. J. Thomas

2004-11-01T23:59:59.000Z

491

Constraints on Solutions of Long's Equation for Steady, Two-Dimensional, Hydrostatic Flow over a Ridge  

Science Conference Proceedings (OSTI)

Two-dimensional, stratified shear flow over a ridge is considered. The finite-amplitude disturbances are steady and hydrostatic, and solutions are derived from the Boussinesq from the Long's equation. Two limiting solutions are examined; viz., 1) ...

William Blumen

1989-05-01T23:59:59.000Z

492

Mean Circulation and Internal Variability in an Ocean Primitive Equation Model  

Science Conference Proceedings (OSTI)

A primitive equation World Ocean model has been integrated with restoring boundary conditions to reach a steady state. The global distribution of potential temperature, salinity, and meridional streamfunction are consistent with observations. In ...

Sybren Drijfhout; Christoph Heinze; Mojib Latif; Ernst Maier-Reimer

1996-04-01T23:59:59.000Z

493

A Pointwise Energy Diagnostic Scheme for Multilayer, Nonisopycnic, Primitive Equation Ocean Models  

Science Conference Proceedings (OSTI)

Considered is a pointwise energy diagnostic scheme for a multilayer, primitive equation, nonisopycnic ocean model. Both conservative as well as nonconservative energy exchange terms are considered. Moreover, the scheme is worked out for both the ...

Lars Petter Rřed

1999-08-01T23:59:59.000Z

494

Constrained and unconstrained growth : applying the Avrami Equation to the production of materials  

E-Print Network (OSTI)

Production of materials which are limited by the amount available on the earth's surface follow a growth curve similar to the Avrami equation which governs the process of nucleation and growth. This thesis will analyze ...

See, Marianna B. (Marianna Blackman)

2013-01-01T23:59:59.000Z

495

Stability issues in the quasineutral limit of the one-dimensional Vlasov-Poisson equation  

E-Print Network (OSTI)

-Poison equation for ions. . . . . . . . . . . . . . . . . . . 14 2.6 Organization of the following of the paper of Theorems 2.2 and 2.3 27 4.1 Some properties of the Casimir functional HQ

Hauray, Maxime

496

The Primitive Equations in the Stochastic Theory of Adiabatic Stratified Turbulence  

Science Conference Proceedings (OSTI)

The stochastic theory of compressible turbulent fluid transport recently developed by Dukowicz and Smith is applied to the ensemble-mean primitive equations (PEs) for adiabatic stratified flow. The theory predicts a generalized Gent–McWilliams ...

Richard D. Smith

1999-08-01T23:59:59.000Z

497

Analytic Solution of a One-Dimensional Equation for Aerosol and Gas Dispersion in the Stratosphere  

Science Conference Proceedings (OSTI)

The one-dimensional equation for dispersion of an inert tracer in an exponentially stratified fluid with exponential dispersion coefficient admits a simple analytic solution. The solution is a form of the gamma distribution of which the usual ...

J. Ben Liley

1995-09-01T23:59:59.000Z

498

Multicomponent, Multiphase Thermodynamics of Swelling Porous Media with Electroquasistatics: I. Macroscale Field Equations  

E-Print Network (OSTI)

A systematic development of the macroscopic field equations (conservation of mass, linear and angular momentum, energy, and Maxwell’s equations) for a multiphase, multicomponent medium is presented. It is assumed that speeds involved are much slower than the speed of light and that the magnitude of the electric field significantly dominates over the magnetic field so that the electroquasistatic form of Maxwell’s equations applies. A mixture formulation is presented for each phase and then averaged to obtain the macroscopic formulation. Species electric fields are considered, however it is assumed that it is the total electric field which contributes to the electrically induced forces and energy. The relationships between species and bulk phase variables and the macroscopic and microscopic variables are given explicitly. The resulting field equations are of relevance to many practical applications including, but not limited to, swelling clays (smectites), biopolymers, biological membranes, pulsed electrophoresis, and chromatography.

Lynn Schreyer Bennethum; John H. Cushman

2001-01-01T23:59:59.000Z

499

Bubble Convection Experiments with a Semi-implicit Formulation of the Euler Equations  

Science Conference Proceedings (OSTI)

Atmospheric models based on the Euler equations exist and are used occasionally to carry out numerical experiments. Such a model is used here to simulate the motion of warm bubbles in a dry isentropic atmosphere. For the time integration, this ...

André Robert

1993-07-01T23:59:59.000Z

500

Radiative transfer in plane-parallel media and Cauchy integral equations III. The finite case  

E-Print Network (OSTI)

We come back to the Cauchy integral equations occurring in radiative transfer problems posed in finite, plane-parallel media with light scattering taken as monochromatic and isotropic. Their solution is calculated following the classical scheme where a Cauchy integral equation is reduced to a couple of Fredholm integral equations. It is expressed in terms of two auxiliary functions $\\zeta_+$ and $\\zeta_-$ we introduce in this paper. These functions show remarkable analytical properties in the complex plane. They satisfy a simple algebraic relation which generalizes the factorization relation of semi-infinite media. They are regular in the domain of the Fredholm integral equations they satisfy, and thus can be computed accurately. As an illustration, the X- and Y-functions are calculated in the whole complex plane, together with the extension in this plane of the so-called Sobouti's functions.

B. Rutily; L. Chevallier; J. Bergeat

2006-01-16T23:59:59.000Z