Browsing Scholarly Works, Department of Mathematics by Author "Virginia Tech"
Now showing items 2140 of 123

Asymptotics of the scattering coefficients for a generalized Schrödinger equation
Aktosun, T.; Klaus, M. (AIP Publishing, 199908)The generalized Schrodinger equation d(2)psi/dx(2) + F(k)psi=[ikP(x) + Q(x)]psi is considered, where P and Q are integrable potentials with finite first moments and F satisfies certain conditions. The behavior of the ... 
Canonical dual approach to solving 01 quadratic programming problems
Fang, S. C.; Gao, D. Y.; Sheu, R. L.; Wu, S. Y. (American Institute of Mathematical Sciences, 200802)This paper presents a canonical duality theory for solving nonconvex polynomial programming problems subjected to box constraints. It is proved that under certain conditions, the constrained nonconvex problems can be ... 
Capillarygravity wave drag
Sun, S. M.; Keller, J. B. (AIP Publishing, 200108)Drag due to the production of capillarygravity waves is calculated for an object moving along the surface of a liquid. Both two and three dimensional objects, moving at large Froude and Weber numbers, are treated. (C) ... 
Case eigenfunction expansion for a conservative medium
Greenberg, W.; Zweifel, P. F. (AIP Publishing, 197602)By using the resolvent integration technique introduced by Larsen and Habetler, the one‐speed, isotropic scattering,neutron transport equation is treated in the infinite and semi‐infinite media. It is seen that the results ... 
Cauchyproblem for the linearized version of the Generalized Polynomial KdV equation
Yordanov, R. G. (AIP Publishing, 199206)In the present paper results about the "Generalized Polynomial Kortewegde Vries equation" (GPKdV) are obtained, extending the ones by Sachs [SIAM J. Math. Anal. 14, 674 (1983)] for the Kortewegde Vries (KdV) equation. ... 
Comment on "A numerical study of periodic disturbances on twolayer Couette flow" [Phys. Fluids 10, 3056 (1998)]
Renardy, Yuriko Y.; Li, Jie (AIP Publishing, 199910)The flow of fluids with different viscosities, subjected to an interfacial perturbation, can lead to fingering and migration... 
Computational simulation of typeII superconductivity including pinning phenomena
Du, Q.; Gunzburger, M. D.; Peterson, J. S. (American Physical Society, 19950615)A flexible tool, based on the finiteelement method, for the computational simulation of vortex phenomena in typeII superconductors has been developed. These simulations use refined or newly developed phenomenological ... 
Continuity of the S matrix for the perturbed Hill's equation
Clemence, D. P.; Klaus, M. (AIP Publishing, 199407)The behavior of the scattering matrix associated with the perturbed Hill's equation as the spectral parameter approaches an endpoint of a spectral band is studied. In particular, the continuity of the scattering matrix at ... 
Convergence theorems for intermediate problems. II
Beattie, C. A.; Greenlee, W. M. (Cambridge University Press, 2002)Convergence theorems for the practical eigenvector free methods of Gay and Goerisch are obtained under a variety of hypotheses, so that our theorems apply to both traditional boundaryvalue problems and atomic problems. ... 
Couette flow of a binary gas mixture
Valougeorgis, D. (AIP Publishing, 198803)The linearized binary model described by Hamel [Phys. Fluids 8, 418 (1964)] is used to obtain a set of kinetic equations and boundary conditions for the Couette flow problem. The derived set of two coupled integrodifferential ... 
Coupling constant behavior of eigenvalues of ZakharovShabat systems
Klaus, Martin; Mityagin, Boris (AIP Publishing, 200712)We consider the eigenvalues of the nonselfadjoint ZakharovShabat systems as the coupling constant of the potential is varied. In particular, we are interested in eigenvalue collisions and eigenvalue trajectories in the ... 
Coupling constant thresholds of perturbed periodic Hamiltonians
Fassari, S.; Klaus, M. (AIP Publishing, 199809)We consider Schrodinger operators of the form Hlambda= Delta + V + lambda W on L2(Rv) (v=1, 2, or 3) with V periodic, W short range, and lambda a real nonnegative parameter. Then the continuous spectrum of Hlambda ... 
Deformation of a hydrophobic ferrofluid droplet suspended in a viscous medium under uniform magnetic fields
Afkhami, S.; Tyler, A. J.; Renardy, Yuriko Y.; Renardy, Michael J.; St Pierre, T. G.; Woodward, R. C.; Riffle, Judy S. (Cambridge University Press, 201011)The effect of applied magnetic fields on the deformation of a biocompatible hydrophobic ferrofluid drop suspended in a viscous medium is investigated numerically and compared with experimental data. A numerical formulation ... 
Draw resonance revisited
Renardy, Michael J. (Siam Publications, 2006)We consider the problem of isothermal fiber spinning in a Newtonian fluid with no inertia. In particular, we focus on the effect of the downstream boundary condition. For prescribed velocity, it is well known that an ... 
Effect of inertia on drop breakup under shear
Renardy, Yuriko Y.; Cristini, V. (American Institute of Physics, 200101)A spherical drop, placed in a second liquid of the same density and viscosity, is subjected to shear between parallel walls. The subsequent flow is investigated numerically with a volumeoffluid continuoussurfaceforce ... 
Effect of upstream boundary conditions on stability of fiber spinning in the highly elastic limit
Renardy, Michael J. (AIP Publishing, 200207)We consider fiber spinning for the upperconvected Maxwell fluid in the limit of a high Deborah number. We compare several choices of boundary conditions that may be imposed. In addition to the takeup speed and the upstream ... 
Erratum: "derivation of amplitude equations and analysis of sideband instabilities in twolayer flows" (vol 5, pg 2738, 1993)
Renardy, Michael J.; Renardy, Yuriko Y. (AIP Publishing, 199410)In the amplitude equations, one further term should have been taken into account. This term is formally of higher order when the original scaling of variables is used. However, the analysis of sideband instabilities involves ... 
Exact behavior of Jost functions at low energy
Klaus, M. (AIP Publishing, 198801)For Schrödinger operators with central potential q(r) and angular momentuml, the behavior of the Jost function F l (k) as k→0 is investigated. It is assumed that ∫∞ 0 d r (1+r)σ‖q(r)‖<∞, where σ≥1. Situations where q is ... 
Expansionfree electromagnetic solutions of KerrSchild class
Debney, G. (AIP Publishing, 197407)Starting with the general Kerr_Schild form of the metric tensor,d s2=_+l_l (where l is null and _ is flat space_time), a study is made for those solutions of the Einstein_Maxwell equations in which l is geodesic, shear_free, ... 
Experimental observation and matching numerical simulation for the deformation and breakup of immiscible drops in oscillatory shear
Wannaborworn, S.; Mackley, M. R.; Renardy, Y. (AIP Publishing, 200209)This paper describes experimental results on the way immiscible drops of a Newtonian fluid can deform and breakup when subject to oscillatory shear deformation. The paper also reports a matching threedimensional numerical ...