Conferences, Lectures, & Seminars
Events for February
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Materials Science Seminar
Fri, Feb 02, 2007 @ 02:45 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
THE MORK FAMILY DEPARTMENT OF CHEMICAL ENGINEERING AND MATERIALS SCIENCEPresents:Microscale Flow and Transport Problems arising in Surfactant Rheology, Printing Processes, and Polymer ElectrophoresisBy:Professor Satish Kumar
Department of Chemical Engineering and Materials Science
University of MinnesotaAbstractFluid flow and transport processes occurring on length scales of microns or less often involve phenomena which are unimportant at larger length scales. Although such phenomena can complicate our ability to understand and design microscale flow and transport processes, they also offer opportunities to engineer novel and useful effects. Three examples will be presented in this talk in support of this idea. In the first example, we consider an instability that arises when a fluid flows past a soft elastic solid. Experiments and theory suggest that this instability is responsible for certain rheological phenomena observed in surfactant solutions, and that it may also be useful for enhancing mixing in microscale flows. In the second example, we consider the displacement of one thin liquid film by another on a chemically patterned surface. Numerical simulations using a lubrication-theory-based model indicate a mechanism by which one liquid can be emulsified into the other, a step which is known to play a key role in lithographic printing processes. In the third example, we consider polymer electrophoresis through a narrow constriction. Brownian dynamics simulations show that the relationship between chain transit velocity and chain length depends in a sensitive way on the constriction geometry and applied electric field strength, and is controlled by an interplay between three distinct time scales.2:45-3:30 PM
(Refreshments will be served at 2:30 PM)First year MASC students are required to attend.Location: John Stauffer Science Lecture Hall (SLH) - 102
Audiences: Everyone Is Invited
Contact: Petra Pearce
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Lyman L. Handy Colloquium
Thu, Feb 08, 2007 @ 12:45 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
MODELING CHEMICAL REACTIVITY: EFFECTS OF CONFINEMENTKeith E. Gubbins
Center for High Performance Simulation (CHiPS) and
Department of Chemical Engineering, North Carolina State University,
Raleigh, NC 27695, USA A goal of theory is to predict chemical reactivity equilibrium composition, reaction mechanisms and reaction rates, as well as diffusion limitations from first principles. At present our ability to achieve this is quite limited, for a number of reasons. First, ab initio methods are necessary, since electrons are rearranged, but these are computationally very demanding, and with current supercomputers we are quite limited in the length and time scales that can be accessed; moreover, the scaling of the computational burden with the number of electrons is poor. Second, reaction events are rare, and so even if we have the energy landscape for the reaction conventional molecular dynamics simulations are insufficient. A brief review of the most widely used methods to model chemical reactions, at both the electronic and atomistic levels will be presented, with comments on their applicability and a description of their strengths and weaknesses1. In many applications a combination of ab initio and semi-classical atomistic simulations will be needed. Specialized atomistic simulation methods are usually necessary, since the reactions are themselves rare events, and the free energy landscape for the reaction is often rugged with many possible reaction paths. Chemical reactions are often carried out in nano-structured materials, which can enhance reactions due to their large specific surface area, their interactions with the reacting mixture and confinement effects. An experimental investigation of the role of each possible catalytic effect is challenging, since experimental measurements reflect an integration over multiple catalytic effects. In this talk several of the different factors that can influence a chemical reaction in confinement will be considered. We first consider the influence of steric hindrance on the equilibrium and kinetics for the rotational isomerizations of several small hydrocarbons. These examples illustrate how reaction rates can vary doubly exponentially with the dimensions of the confining material (the 'shape-catalytic' effect). As a second example, we consider the unimolecular decomposition of formaldehyde on graphitic carbon pores of various sizes . These results illustrate the influence of electrostatic interactions with the supporting material on the reaction mechanism and equilibrium yield for reactions involving a charge transfer. As a final example, we consider the interaction of a water molecule with a defective carbon substrate as an example of a chemical interaction that can be enhanced through a shape-catalytic effect. We show using ab initio calculations how a vacancy site on a carbon surface can induce the thermal splitting of water at relatively low temperatures . We also examine the dissociation on a vacancy site on a nanotube surface, which shows the shape-catalytic effect of the surface curvature. These results are a first step toward the design of catalytic materials that take advantage of different enhancing effects simultaneously. 1 E. Santiso and K.E. Gubbins, "Multi-Scale Molecular Modeling of Chemical Reactivity", Molecular Simulation, 30, 699-748 (2004).2 M. Kostov, E.E. Santiso, A.M. George, K.E. Gubbins and M. Buongiorno Nardelli, "Catalytic role of defective carbon substrates in the dissociation of water", Physical Review Letters, 95, 136105 (2005).Refreshments will be served after the seminar in the HED Lobby
The Scientific Community is Cordially Invited.
Location: Olin Hall of Engineering (OHE) - 122
Audiences: Everyone Is Invited
Contact: Petra Pearce
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NanoSystems Biology and New Technologies for in vitro and in vivo Diagnostics of Cancer
Wed, Feb 21, 2007 @ 03:30 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
THE MORK FAMILY DEPARTMENT OF CHEMICAL ENGINEERING AND MATERIALS SCIENCEPresents the The First
William G. Spitzer LecturebyProfessor James R. Heath
Department of Chemistry
The California Institute of Technology
Pasadena, CAonNanoSystems Biology and New Technologies for
in vitro and in vivo Diagnostics of Cancer
Wednesday, Feb 21, 2007
3:30 5:00 PM
Andrus Gerontology Center (GER 124)
University Park Campus
The emerging world of personalized, preventative, predictive, and
participatory (P4) medicine will likely be enabled by the developing field of
systems biology. Systems biology and P4 medicine are both data driven and,
accordingly, both require new tools for making large numbers of measurements
rapidly, quantitatively, and inexpensively. Microfluidics, chemical, and
nanotechnologies will revolutionize our ability to generate comprehensive data sets
that span from individual cells to patients, and will allow us to build
multiparameter analysis tools (quantitating genes, proteins, and cells) for achieving
an informative in vitro disease diagnosis, as well as in vivo molecular imaging
probes for spatially localizing specific diseases. Using cancer as a theme, I will
describe the state-of-the-art in terms of network models of human diseases, and I
will describe how those models may be harnessed for information that can impact
clinical care of cancer. I will then describe a suite of in vitro and in vivo
multiparameter diagnostics technologies that we are developing in my lab in
concert with other groups, in the context of both near term and far term
applications.Reception 5:00-5:45 PM
Host: Anupam Madhukar, (213) 740-4325.Location: Ethel Percy Andrus Gerontology Center (GER) - ontology Auditorium, GER 124
Audiences: Everyone Is Invited
Contact: Petra Pearce
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MECHANISMS OF TRANSPORT ACROSS THE ALVEOLAR EPITHELIAL BARRIER: FROM IONS TO NANOPARTICLES
Thu, Feb 22, 2007 @ 12:45 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Mork Family Department of Chemical Enginering and Materials SciencePresents a Distinguished Lecture by Professor Edward CrandallMECHANISMS OF TRANSPORT ACROSS THE ALVEOLAR EPITHELIAL BARRIER: FROM IONS TO NANOPARTICLESAbstract Interest in nanotechnology has greatly expanded in recent years, driven in part by growth in manufacturing and applications that range widely from fabrication of useful nanoscale circuitry and robotics to biological applications of nanomaterials in imaging and transduction at the cellular and molecular levels. Nanoparticles promise to be useful for many biomedicine-related applications, yet their toxicity, trafficking characteristics across cells, and specific pathways and mechanisms of uptake into pneumocytes are not well known. The lung can serve as a portal for entry for nanomaterials (ambient and/or manufactured) into the systemic circulation. Inhaled nanoparticles can be found in heart, bone marrow, blood vessels and other organs, and their most likely route of entry into the circulation is across the epithelia of the lung, especially the alveolar epithelium with its very large surface area and thin barrier thickness. Further knowledge about the mechanisms by which particles injure, interact with and/or are transported across the alveolar epithelium is thus of considerable importance for understanding health effects related to inhalation of nanoparticles in ambient air. Nevertheless, nanoparticle-based drug/gene delivery and other biological applications may be important to pursue, even though biocompatibility and toxicity of such nanomaterials are not yet well defined. To explore interactions with the air-blood barrier of distal lung, nanoparticle injury of, uptake into and trafficking across alveolar epithelial cells were investigated. Polystyrene nanoparticles (PNP) of different surface charge and size were utilized as models of defined manufactured nanomaterials. Results indicate that (1) all PNP are non-toxic to the cells, (2) PNP translocate transcellularly across rat alveolar epithelial cell monolayers, and (3) transepithelial trafficking of PNP is markedly influenced by nanoparticle surface charge density and size. Specific mechanisms underlying these interactions remain to be fully determined.
Location: Olin Hall of Engineering (OHE) - 122
Audiences: Everyone Is Invited
Contact: Petra Pearce
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Stochastic Uncertainty Quantification Approaches for Large Scale Subsurface Problems
Fri, Feb 23, 2007 @ 11:15 AM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Graduate SeminarStochastic Uncertainty Quantification
Approaches for Large Scale Subsurface
ProblemsProfessor Dongxiao Zhang
Petroleum and Geological Engineering
The University of OklahomaAbstract
Prediction of subsurface flow and transport is subject to uncertainties, which can
result from the heterogeneity of the media and our incomplete knowledge about
their properties. Such uncertainties render the model parameters random and the
equations describing flow and transport in the media stochastic. Monte Carlo
simulation method (MCS) is the most common and conceptually straightforward
approach. However, it requires large computational efforts, especially for large scale
problems. Recently, a number of alternative stochastic approaches have been
developed to quantifying prediction uncertainties. This talk discusses four
representative methods: The moment equation method (ME); the Galerkin
polynomial chaos expansion method (PCE); the Karhunen-Loeve based moment
equation method (KLME); and the probabilistic collocation method (PCM). The
efficiency of these methods depends on how the random (probability) space is
approximated. Detailed theoretical analyses and numerical computations are
performed to compare these methods against MCS in terms of accuracy, efficiency,
validity range, and compatibility with existing deterministic simulators. It is found that
the KLME, PCE and PCM are generally more efficient than the MCS and the ME for
larger-scale problems. The expansions in representing the dependent random fields
and the ways for evaluating the expansion coefficients distinguish among the KLME,
PCE and PCM.Friday, February 23, 2007
Seminar at 11:15 a.m.
HED 116The Scientific Community is cordially invited.Location: Hedco Pertroleum and Chemical Engineering Building (HED) - 116
Audiences: Everyone Is Invited
Contact: Petra Pearce
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DEFORMATION AND FAILURE OF COMPOSITE STRUCTURES
Fri, Feb 23, 2007 @ 02:45 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
THE MORK FAMILY DEPARTMENT OF CHEMICAL ENGINEERING AND MATERIALS SCIENCEPRESENTS A JOINT SEMINAR
BYChiara Bisagni
Ph.D., Fulbright FellowDepartment of Mechnical Engineering
Massachusetts Institute of TechnologyDEFORMATION AND FAILURE OF COMPOSITE STRUCTURESABSTRACTAfter a brief presentation of the research activities and experimental facilities of the Department of Aerospace Engineering of Politecnico di Milano, Italy, the lecture will focus on the experimental and numerical investigations carried out by Chiara Bisagni during the last years concerning mainly composite structures under buckling and energy absorption requirements.The first part of the presentation will consider the structural behavior of composite structures under buckling requirements. Some results on stringer stiffened composite panels subjected to buckling under compression and shear will be presented. In particular, the investigation of fuselage panels and of a helicopter tailplane performed during two European projects (POSICOSS, "Improved post-buckling simulation for design of fibre composite stiffened structures", and COCOMAT, "Improved MATerial Exploitation at Safe Design of COmposite Airframe Structures by Accurate Simulation of Collapse") will be presented. Also, the first results of the research now under way will be presented. It considers cyclic buckling tests on composite boxes with combined loads, and the detection of damage propagation during the tests on stiffened buckling structures.The second part of the presentation will consider energy absorption requirements. Indeed, crashworthiness related to composite materials has now become a serious issue, as composite structures have the possibilities to absorb an even superior amount of energy compared to metals, with contained costs. But the crash analysis of composite structures remains particularly challenging due to the complexity and diversity of failure modes that composites exhibit under crushing loads.
The experimental and numerical investigation on the energy absorbing capabilities of intersection elements for helicopter subfloor, and of Formula One car components will be presented. In particular, a building block approach has been used to calibrate the numerical model, analyzing at first coupon testing and tube crushing experiments, and then crash tests of the helicopter and Formula One car componentsFebruary 23, 2007
2:45-3:45 PM
(Refreshments will be served at 2:30 PM)
SLH 102**ALL FIRST YEAR MATERIALS SCIENCE MAJORS ARE REQUIRED TO ATTEND**
Location: John Stauffer Science Lecture Hall (SLH) - 102
Audiences: Everyone Is Invited
Contact: Petra Pearce