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Professor Victor Vasquez
University of Nevada, Reno
Mesoscopic Modeling of Complex Systems:
Dissipative Particle Dynamics and Minimal Models
Abstract
Computer simulation of molecular models is a useful and powerful tool to
study the basic physical behavior of complex systems. It can be used as an
analysis tool between theory and experiments. Most of the molecular
simulation of work is performed using Molecular Dynamics (MD) and Monte
Carlo (MC) methods using atomistic models. At a macroscopic level,
computational continuum mechanics is the most common approach in computer
simulation. However, there is a substantial gap (time-wise and lengthwise)
between macroscopic and atomic scales. Important efforts to narrow this gap
have been reported by the research community. Among them, Stokesian Dynamics
(SD), Brownian Dynamics, and more recently, Dissipative Particle Dynamics (DPD).
In this talk, we explore the potential and limitations of DPD for the study
and analysis of complex systems such as reverse micelles and
polymer--surfactant systems. Preliminary simulation results show that the
technique has the potential to provide significant insight on the behavior
of these complex systems. Another way to understand the general behavior of
complex systems is by developing simplified models (minimal models) that
capture the basic physical behavior of the system. Such models have the
potential of explaining phenomenological behavior without getting into the
details of the system. Examples of this type are simple chain models for the
study of folding in biopolymers such as polypeptides andpolynucleotides.
Many of these models are able to predict unique features of complex
biopolymers such as proteins. These include transitions such as
coil-globule, coil-helix, and freezing or locking. In this presentation, we
discuss some preliminary simulation results of a minimal model using a
square--well (SW) chain on which we control the bond length. By controlling
the stiffness of the chain, the model is able to produce different
transitions and behavior typically observed in more sophisticated potential
models.
Biosketch
Victor R. Vasquez is an assistant professor of Chemical Engineering at
University of Nevada, Reno (UNR). He completed his bachelor degree
(Licentiate) in Chemical Engineering from the University of Costa Rica in
1991. Then, he worked as a consultant for the Interamerican Bank of
Development transferring technology--based projects in different countries
in Latin America; he also consulted for several companies in Costa Rica
including the Costa Rican Petroleum Refining Company. He worked as an
instructor and researcher for the University of Costa Rica for several
years. He began graduate studies in Chemical Engineering in 1996 at West
Virginia University and then transferred to University of Nevada, where he
completed his M.S. and Ph.D. degrees, all in Chemical Engineering. His
research interest include uncertainty analysis of thermodynamic models and
process flow-sheets, process synthesis and simulation, parallel computing,
and thermodynamics of complex fluids using molecular simulation methods.
Recent interests involve the robustness and sensitivity analysis of drug
delivery models coupled with model predictive control. Currently, his
research is funded by private companies and the National Science Foundation.
DATE: May 5, 2004
TIME: 10:10—11:00 a.m.
PLACE: Bourns Hall A265
Refreshments are provided |
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