SUNMONTUEWEDTHUFRISAT
Conferences, Lectures, & Seminars
Events for February
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BIODIESEL COMBUSTION AND EMISSIONS
Wed, Feb 07, 2007 @ 03:30 PM - 04:30 AM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
André Boehman Professor of Fuel ScienceDepartment of Energy and Geo-Environmental EngineeringPennsylvania State UniversityAbstractIn this work, we consider the behavior of biodiesel fuels during diesel combustion, including the injection process, pollutant formation and the characteristics of the pollutants. Topics covered include the unique features of the ignition process for biodiesel fuels, the anomalous "NOx Effect" that is observed in diesel engines running on biodiesel and impacts of biodiesel on the characteristics of diesel soot. Past and ongoing work seeks to relate the nanostructure and oxidative reactivity of soot. This work shows that the initial structure alone does not dictate the reactivity of diesel soot and rather the initial oxygen groups have a strong influence on the oxidation rate. A comparison of the complete oxidation behavior and burning mode was made to address the mechanism by which biodiesel soot enhances oxidation. Diesel soot derived from neat biodiesel (B100) is far more reactive during oxidation than soot from neat Fischer-Tropsch diesel fuel (FT100). B100 soot undergoes a unique oxidation process leading to capsule-type oxidation and eventual formation of graphene ribbon structures. Incorporation of greater surface oxygen functionality in the B100 soot provides the means for more rapid oxidation and drastic structural transformation during the oxidation process. These characteristics of diesel soot have implications for the operation and regeneration of diesel particulate filters and, as a consequence of the coupling that can arise between particulate and NOx controls, for the operation of urea-selective catalytic reduction of NOx.
Location: Seaver Science Library, Rm 150
Audiences: Everyone Is Invited
Contact: April Mundy
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Biological Materials, Biomaterials and Biomimetics
Thu, Feb 08, 2007 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Ulrike G.K. WegstMax-Planck-Institut für Metallforschung, Stuttgart, GermanyLawrence Berkeley National Laboratory, Berkeley, CAAbstract: Biological materials and their skilled use have played a key role in the development of mankind and technology, and the course of history. After millions of years, they are still of great importance today and used both as low cost, high volume materials and as materials for high-tech applications. One reason for their success is that they have properties which cannot easily be emulated by man-made materials, yet. Their striking mechanical efficiency is primarily due to their hierarchical structure which provides them with the potential of optimisation at each structural level, resulting in stiff, strong and tough composites even though, from a mechanical point of view, there is nothing very special about the individual components. The considerable advantage which we have over our ancestors today is that we cannot only use biological materials in their "native" state, but that we have the tools to investigate and test them at almost all levels of their structural hierarchy. With an informed evaluation of their structure, properties and function, principles of optimisation may thus be identified that allow for the development of new or improved man-made materials. Illustrated in this talk will be how the mechanical efficiency and optimisation of biological materials, ranging from bone to seaweed and from mollusc shell to bamboo, can be evaluated and compared with engineering materials. A variety of methods for the structural characterisation of biological materials and their hierarchical composite structure, ranging from synchrotron-based x-ray microtomography to a novel method for in situ mechanical testing in an SEM or FIB, will be presented. Finally, an example for a systematic knowledge transfer from nature to technology that resulted in the successful development of a biomimetic bone-substitute material will be given.
Location: Von Kleinsmid Center For International & Public Affairs (VKC) - 256
Audiences: Everyone Is Invited
Contact: April Mundy
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Nonlinear Dynamics of Multi-Mesh Gear Systems
Wed, Feb 14, 2007 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Prof. Robert ParkerDepartment of Mechanical EngineeringOhio State UniversityGear vibration dominates helicopter cabin noise, which can exceed 110 dB. Gear vibration is a major concern in numerous other applications including aerospace, automotive, wind turbines, high-speed machinery, manufacturing, and more. Despite gears' long history, scientific study of their dynamics has been concentrated in the last 40 years, and the pervasive impact of nonlinearities and parametric instability in gear vibration has been realized only in the last decade. Mathematical models are emerging to incorporate these critical aspects. Planetary gears and other systems having multiple interacting tooth meshes exhibit especially interesting dynamics that remain largely unexplored. Nonlinearity from tooth contact loss and parametric instability from varying contact conditions as the gears rotate are essential features of complex phenomena observed in practice. After giving industrial examples motivating the research, the presentation will focus on modeling and analysis of the nonlinear dynamics of planetary gears using asymptotic and finite element/contact mechanics methods. In addition to illustrating and explaining the rich range of nonlinear dynamics that emerge, the analytical approximations generate results with clear practical implications. An ambitious $2.1M experimental gear dynamics program with specialized facilities that are unique worldwide will also be discussed.Professor Robert Parker has been at the Ohio State Department of Mechanical Engineering since 1996. He received his M.S. and Ph.D. degrees from the University of California, Berkeley. His research investigates problems on the dynamics, vibration, and stability of mechanical systems with particular focus on high-speed devices. He has held visiting research appointments at INSA Lyon (France), Risoe National Lab (Denmark), NASA Glenn Research Center, the University of Technology-Sydney, and Tokyo University. He worked for two years in the Spacecraft Dynamics division of The Aerospace Corporation in Los Angeles. He consults internationally on vibration problems in numerous industries.Prof. Parker has received over $5M of research funding from the National Science Foundation, U.S. Army Research Office, NASA, National Rotorcraft Technology Center, General Motors, Ford, Boeing, Sikorsky, and other companies. Prof. Parker is a Fellow of ASME and AAAS. He was one of a select group invited to National Academy of Engineering Frontiers of Engineering Symposia in the US and Germany. He received the Presidential Early Career Award for Scientists and Engineers (PECASE) in 1999, which is "the highest honor awarded by the U.S. government to scientific researchers early in their careers," as well as the NSF CAREER and Army Young Investigator Awards.
Location: Seaver Science Library, Rm 150
Audiences: Everyone Is Invited
Contact: April Mundy
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The Mechanics of Cell Migration and the Cytoskeleton
Tue, Feb 20, 2007 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Juan Carlos del Alamo Mechanical and Aerospace Engineering DepartmentUniversity of California at San DiegoSan Diego, CA Motility of eukaryotic cells is essential for many biological processes such as embryonic development or tissue renewal, as well as for the function of the immune and nervous systems. If misregulated, motility plays an important part in diverse diseases such as cancer, osteoporosis, and mental retardation. Cell migration over surfaces is an integrated chemical and physical process involving the cytoskeleton and its mechanical interaction with the substrate through discrete adhesion regions. Precise quantitative knowledge of the bio-physical processes involved in cell migration is limited. Better measurements are needed to ultimately build models with predictive capabilities. The free-living soil amoeba Dictyostelium has proven to be a valuable model system for the investigation of cell motility with extensive similarities to higher eukaryotes in general, and leukocytes in particular. We present an improved force cytometry method and apply it to the analysis of the dynamics of the chemotactic migration of the amoeboid form of Dictyostelium discoideum. Our explicit calculation of the adhesion force field takes into account the finite thickness of the elastic substrate and improves the accuracy and resolution compared to previous methods. This enables us to quantitatively study the differences in the mechanics of the migration of wild-type and mutant cell lines up a chemoattractant gradient. The time evolution of the elastic energy exerted by the crawling cells on their substrate is quasi-periodic and can be used as a simple indicator of the different phases of the cell crawling cycle. We find that the period of the elastic energy cycle correlates strongly with the mean velocity of migration regardless of cell type. Furthermore, we show that when cells adhere to the substrate, the exert opposing pole forces that are orders of magnitude higher than the force required to overcome the resistance from their environment.
Location: Von Kleinsmid Center (VKC) Room 101
Audiences: Everyone Is Invited
Contact: April Mundy
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Collective Motion and Decision-Making in Animal Groups
Wed, Feb 21, 2007 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Iain Couzin Royal Society University Research Fellow
Department of Zoology
University of Oxford
Oxford, UK and Visiting Research Fellow
Pew Program in Biocomplexity
Princeton University Princeton, NJ 08544 Our research focuses on understanding collective behavior; how large-scale biological patterns result from the actions and interactions of the individual components of a system. We study self-organised pattern formation in a wide range of biological systems, including ants, fish schools, bird flocks, locust / cricket swarms and human crowds.Location: Seaver Science Library (SSL) Room 150
Audiences: Everyone Is Invited
Contact: April Mundy
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How Do You Count Individual Biological Bonds
Thu, Feb 22, 2007 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Todd Sulchek Staff ScientistBiosecurity and Nanosciences LaboratoryLawrence Livermore National Laboratory My research program focuses on the measurement and prediction of how multiple individual biological bonds produce a coordinated function within molecular and cellular systems. In particular I focus on two complementary goals. The first is to understand the kinetics of multivalent pharmaceuticals during their targeting of disease markers. The second is to quantify the host cell signal transduction resulting from pathogen invasion. We develop and employ several tools to accomplish these goals. The primary platform for study is the atomic force microscope (AFM), which controls the 3D positioning of biologically functionalized micro- and nanoscale mechanical probes. This talk will describe our method of using single molecule dynamic force spectroscopy to determine the binding strength of antibody- protein complexes as a function of binding valency in a direct and simple measurement. We used the atomic force microscope to measure the force required to rupture a single complex formed by the MUC1 protein, a cancer indicator, and therapeutic antibodies that target MUC1. We will show that nanomechanical polymer tethers can be used in a completely novel manner to count the number of biological bonds formed. Mechanical work (on the scale of a few kBT!) will disrupt these bonds and can quantify the overall kinetics. This ability to form, count and dissociate biological bonds with nanomechanical forces provides a powerful method to study the physical laws governing the interactions of the biological molecules.
Location: Troyland Apartments (TAP) - er Hall of Humanities, (THH) Rm 116
Audiences: Everyone Is Invited
Contact: April Mundy
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Ion Mobility Analysis of Gaseous and Particulate Pollutants
Wed, Feb 28, 2007 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
ANTHONY S. WEXLERDepartment of Mechanical and Aeronautical EngineeringDepartment of Civil and Environmental EngineeringDepartment of Land, Air and Water ResourcesUniversity of California, DavisAbstract:USC faculty, staff and students have played a leading roll internationally in elucidating the physical and chemical constituents in the atmosphere and the health effects that they elicit. But like investigators everywhere, this work has been limited by the spatial resolution of the instruments that are available. Usually, a few measurements in a vast urban area such as Los Angeles must suffice due to instrument costs even though there are tremendous spatial inhomogeneities for many of the toxic pollutants. This talk will present a nascent effort at UC Davis to design and build an inexpensive, easily manufactured ion mobility spectrometer that is suitable for analyzing many common pollutants, especially the organic ones.Location: Seaver Science Library (SSL) Room 150
Audiences: Everyone Is Invited
Contact: April Mundy
