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Search Publications by: James A. Warren (Fed)

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Displaying 51 - 75 of 181

The Effect of Substrate Material on Silver Nanoparticle Antimicrobial Efficacy

December 1, 2010
Author(s)
Benita Dair, Dave M. Saylor, T. E. Cargal, Grace R. French, Kristen M. Kennedy, Rachel S. Casas, Jonathan E. Guyer, James A. Warren, Steven K. Pollack
With the advent of Nanotechnology, silver nanoparticles increasingly are being used in coatings, especially in medical device applications, to capitalize on their antimicrobial properties. The increased antimicrobial efficacy of nanoparticulate silver

Effect of Phase Change and Solute Diffusion on Spreading on a Dissolving Substrate

October 1, 2010
Author(s)
Walter Villanueva, William J. Boettinger, James A. Warren, Gustav Amberg
Dissolutive wetting is investigated numerically using a diffuse-interface model that incorporates fluid flow, solute diffusion, and phase change. A range of materials parameters are investigated that: 1) permits recovery of the hydrodynamic limit by

Predicting Microstructure Development During Casting of Drug Eluting Coatings

September 19, 2010
Author(s)
David M. Saylor, Jonathan E. Guyer, Daniel Wheeler, James A. Warren
We have devised a novel diffuse interface formulation to model the development of chem- ical and physical inhomogeneities, i.e. microstructure, during the process of casting drug eluting coatings. These inhomogeneities, which depend on the coating

Modeling Reactive Wetting when Inertial Effects are Dominant

June 30, 2010
Author(s)
Daniel Wheeler, James A. Warren, William J. Boettinger
Recent experimental studies of molten metal droplets wetting and spreading on high temperature reactive substrates have established that the majority of triple-line motion occurs when inertial effects are dominant. In light of these studies, this paper

A Multicomponent and Multiphase Model of Reactive Wetting

June 4, 2010
Author(s)
Walter Villanueva, William J. Boettinger, Geoffrey B. McFadden, James A. Warren
A diffuse-interface model of reactive wetting with intermetallic formation is presented. The model incorporates fluid flow, solute diffusion, and phase change that are based on the total molar Gibbs energy of a ternary system with four phases. Numerical

Grain boundaries exhibit the dynamics of glass-forming liquids

May 12, 2009
Author(s)
James A. Warren, Jack F. Douglas, Xuhang Tong, David J. Srolovitz
Polycrystalline materials are composites of crystalline particles or grains separated by thin amorphous grain boundaries (GBs). Although GBs have been exhaustively investigated at low temperatures, at which these regions are relatively ordered, much less

FiPy: PDEs in Python

February 23, 2009
Author(s)
Jonathan E. Guyer, Daniel Wheeler, James A. Warren
Partial differential equations (PDEs) are ubiquitous to the mathematical description of physical phenomena. They describe the relationships between functions of more than one independent variable and partial derivatives with respect to those variables

Phase Field Approach to Heterogeneous Crystal Nucleation in Alloys

January 11, 2009
Author(s)
James A. Warren, T Pusztai, L Kornyei, L Granasy
We extend the phase field model of heterogeneous crystal nucleation developed recently [L. Granasy, T. Pusztai, D. Saylor, and J. A. Warren, Phys. Rev. Lett. 98, 035703 (2007)] to binary alloys. Three approaches are considered to incorporate foreign walls

A Finite Volume PDE Solver Using Python (FiPy)

October 16, 2008
Author(s)
Jonathan E. Guyer, Daniel Wheeler, James A. Warren
We present an object oriented partial differential equation (PDE) solver written in Python based on a standard finite volume (FV) approach.The solution of coupled sets of PDEs is ubuquitous in the numerical simulation of science problems. Numerous PDE

Computational Materials Science and Industrial R&D: Accelerating Progress

October 16, 2008
Author(s)
S C. Glotzer, James A. Warren
Computtional materials research has made major advances over the past decade in accelerating the design, processing and performance of technologically important materials. materials simulation is, however, still in its infancy, as the nature of mateirals

Nature Materials News and Views on T. Haxhimali et al

October 16, 2008
Author(s)
James A. Warren
Simulations of dendritic solidification by T. Haxhimali et al. [1] for a pure material and comparisons with experiments in an A1Zn alloy system have shown that a standard theoretical rule of thumb for predicting solidification growth forms can dramatically