U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: William L. George (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 26 - 50 of 76

Development of Standard Reference Materials for Cement-Based Materials

January 6, 2014
Author(s)
Chiara F. Ferraris, Nicos Martys, William L. George
Rotational rheometers are routinely used for homogeneous materials, but their usage for characterization of a granular fluid like concrete is a relatively new phenomenon. As measurements with rheometers can involve flow in a complex geometry, it is

Development of Standard Reference Materials for Cement-Based Materials

May 13, 2013
Author(s)
Chiara F. Ferraris, Nicos Martys, William L. George
Rheometers are used to determine the rheological properties of materials ranging from mayonnaise to concrete. While rotational rheometers are routinely used for homogeneous materials such as mayonnaise, their usage for characterization of a granular fluid

Stress propagation in a colloidal suspension under shear

March 1, 2012
Author(s)
William L. George, Pascal Hebraud, Didier Lootens, Mouhamad Khalil, Nicos Martys
The stress propagation in a concentrated attractive colloidal suspension, under shear, is studied using mumerical simulations. A novel way of describing the intercolloidal stress field is proposed and its spatial correlations are studied. An inertia-like

Advancing the materials science of concrete with supercomputers

January 24, 2011
Author(s)
Jeffrey W. Bullard, Edward Garboczi, William L. George, Nicos Martys, Steven G. Satterfield, Judith E. Terrill
Supercomputers are renowned for being used on grand challenge problems like global weather patterns, nuclear device virtual testing, galaxy formation, unraveling molecular structure - and now concrete! Why do the mysteries of concrete form this kind of a

Contact and Stress Anisotropies in Start Up Flows of Collodial Suspensions

September 11, 2009
Author(s)
Nicos Martys, William L. George, Didier Lootens, Pascal Hebraud
Spatio-temporal correlations in start-up flows of attractive colloids are explored by numerical simulations. The suspension is first allowed to flocculate during a time tw, then the stress necessary to induce its flow is computed. Whereas at low volume

Extending Measurement Science to Interactive Visualization Environments

January 30, 2009
Author(s)
Judith E. Terrill, William L. George, Terence J. Griffin, John G. Hagedorn, John T. Kelso, Thomas M. Olano, Adele P. Peskin, Steven G. Satterfield, James S. Sims, Jeffrey W. Bullard, Joy P. Dunkers, Nicos Martys, Agnes A. O'Gallagher, Gillian Haemer
We describe a method for creating a visual laboratory to interactively measure and analyze scientific data. We move the normal activities that scientists perform to understand their data into the visualization environment. The visualization environment is

Spatial-Temporal Correlations at the Onset of Flow in Concentrated Suspensions

July 7, 2008
Author(s)
Nicos Martys, Didier Lootens, William L. George, Steven G. Satterfield, Pascal Hebraud
Spatial-temporal correlations in the startup-up flow of colloidal suspensions composed of attractive spherical particles under static and shear conditions are studied by computer simulation. The evolution of particle organization with time is followed as

Stress chains formation under shear of concentrated suspension

July 7, 2008
Author(s)
Didier Lootens, Nicos Martys, William L. George, Steven G. Satterfield, Pascal Hebraud
Results comparing experiments on a model system of mono-disperse silica-particles with the numerical simulation of highly concentrated suspension of spherical particles subject to a constant rate of strain are presented. Giant fluctuations of the shear

Accelerating Scientific Discovery through Computation and Visualization III. Tight-binding Wave Functions for Quantum Dots

June 2, 2008
Author(s)
James S. Sims, John G. Hagedorn, Steven G. Satterfield, Terence J. Griffin, William L. George, Howard Hung, John T. Kelso, Thomas M. Olano, Adele P. Peskin, Judith E. Terrill, Garnett W. Bryant, Jose G. Diaz
This is the third in a series of articles that describe, through examples, how the Scientific Applications and Visualization Group (SAVG) at NIST has utilized high performance parallel computing, visualization, and machine learning to accelerate scientific

Science at the Speed of Thought

February 1, 2005
Author(s)
J E. Devaney, Steven G. Satterfield, John T. Kelso, Adele Peskin, William L. George, John G. Hagedorn, Terence J. Griffin, Howard Hung, R D. Kriz

Parallel Programming with Interoperable MPI

February 1, 2004
Author(s)
William L. George, John G. Hagedorn, J E. Devaney
In this article we describe IMPI (Interoperable Message Passing Interface), a message passing protocol that allows you to easily run parallel programs across multiple clusters, SMPs (symmetric multiprocessors), parallel machines, personal computers, and