SUNMONTUEWEDTHUFRISAT
Conferences, Lectures, & Seminars
Events for February
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Uptake and Methylation of Mercury in Planktonic and Biofilm Cultures of Sulfate-Reducing Bacteria
Fri, Feb 01, 2008 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Dr. Chu-Ching Lin, Research Associate, Department of Civil and Environmental Engineering,
University of California, Los AngelesAbstract:
Mercury (Hg) methylation is the most critical Hg transformation in nature because the end product, methylmercury (MeHg), is a potent neurotoxin that can be effectively bioaccumulatd and biomagnified through food chains to become a level of a threat to human health and wildlife reproduction. It is well accepted that the dominant environmental Hg methylation process is mediated biologically, and sulfate-reducing bacteria (SRB) have been identified as the primary Hg methylators in a wide range of aquatic systems. While all previous Hg methylation studies to date have been conducted with planktonic SRB cultures, it is generally believed that the majority of bacteria in the environment live in surface-attached communities, or biofilms. Little work has been undertaken to investigate the role of biofilms in Hg cycling, particularly in the formation of MeHg. In this seminar, the effects of chemical speciation on uptake and methylation of Hg in both planktonic and biofilm cultures of the model microorganisms (E. coli and Desulfovibrio desulfuricans) will be discussed. Also, pathways of Hg methylation that caused the observation of differential Hg methylation capacity between planktonic and biofilm cultures of SRB will be touched.
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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New remote sensing tools for study of the solid Earth
Thu, Feb 07, 2008 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Dr. Tom Farr, Earth and Space Sciences Division, Jet Propulsion Laboratory, Pasadena, CAAbstract:
Last year the National Academy released a report: Earth Science and Applications from Space (http://www.nap.edu/catalog.php?record_id=11820) which provided a blueprint for Earth science missions over the next decade and beyond. These include missions to study Earth's cryosphere, vegetation, soil moisture, and oceans. The missions oriented toward the solid Earth will be described, including the technical challenges and applications.Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Microbial Biofilms : Our Under-Used Allies in Oil Recovery and Bioremediation
Fri, Feb 08, 2008 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Dr. Bill Costerton,
Director, Center for Biofilms, Dentistry, University of Southern,
California - Los Angeles, CAAbstract:Microbiology impacts the formation of oil, the recovery of oil, and the effects of oil recovery operations on the environment. The science of Microbiology is undergoing a radical transformation, from dependence on cultures to a new era in which bacteria are characterized by molecular techniques and studied directly in situ in the ecosystems in which they operate. Bill will discuss the roles that bacteria play in reservoir souring and reservoir plugging, as well as the beneficial role they can play in profile modification and Microbially Enhanced Oil Recovery (MEOR). Bill will also discuss modern methods for the determination of the impact of oil recovery on environmental systems, whose conclusions differ radically from those of the conventional methods used heretofore, and the impact that these new perceptions have on such large issues as the Athabasca Tar Sands operations and the routing of oil from the North Slope to the Continental USA.Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Multiscale Design System
Wed, Feb 13, 2008 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Dr. Jacob Fish, The Rosalind and John J. Redfern Chaired Professor of Engineering; Director, Multiscale Science and Engineering Center, Renssalaer Polytechnic Institute"Multiscale Design System"The first integrated design system for composite materials and structures has been developed and validated at Rensselaer. The multiscale design system (MDS) is a complete environment for analysis and design of structural components made of composites (CMCs, PMCs or MMCs), polycrystals, concrete, soil or any other material system involving microstructure. The MDS consists of the state-of-the-art multiscale analysis tools integrated with the commercial finite element analysis engine and optimization package for model calibration (or parameter identification) and validation. The MDS has been successfully applied to design of polymer matrix based composite cars developed by a consortium of GM, FORD and Chrysler, life prediction of CMC-based JSF components (Rolls-Royce design) and hybrid steel-composite naval ships.
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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A Chemical Perspective of Nano-Cosmetics
Fri, Feb 15, 2008 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Prof. Chang-Chin Kwan,
Department of Applied Chemistry,
Providence University, TaiwanAbstract:Nano-cosmetics have recently raised environmental hazard concerns as nano particles have the ability to be absorbed into skin cells. As the growth of the science becomes enormous, so does the danger and long term risk involved in their use. Nano-cosmetics generally includes nano-sized materials (zinc oxide, titanium dioxide, nano-gold or nano-silver) and perhaps includes nano-carriers (nano-encapsulation, liposome, fullerene, carbon tube and dentrimer).Titanium dioxide usage in cosmetics is very extensive. The titanium dioxide used in cosmetics products is Rutile (R-type, where the photocatalytic effect is not obvious), but Anatase (R-type, a photo-catalyst) is a contaminant in it. In this study we use salicylic acid as a hydroxyl free radical capture agent or dismutant, to confirm whether the cosmetic grade titanium dioxide will produce free radicals or not. An important segment of Dr. Kwan's research includes relating the surfactant with flow properties. His findings show that suspension flow curves at low shear rate (1-15 s-1 by cone-and-plate method) showed a non-Newtonian behavior. Plastic and relative viscosities, along with the Bingham yield, were derived from these flow curves.Magnesium ascorbyl phosphate is commonly used in the productions of whitening and anti-aging materials. It can prevent from the deactivation of tyrosinase and reduction the oxidized melanin. However, magnesium ascorbyl phosphate, a hydrophilic derivative of ascorbic acid, is not stable in the air.
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Investigation of Physico-Chemical Characteristics of Particulate Matter from Vehicular Sources
Tue, Feb 19, 2008 @ 02:30 PM - 05:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Doctoral Dissertation:
Subhasis Biswas,
Sonny Astani Department of Civil and Environmental EngineeringAbstract:
Particles from vehicular sources have drawn public attention for their potential to cause health risks. Beside chemical composition of these particles, their physical attributes are considered to be critical in eliciting adverse health outcomes. This thesis provides valuable information on particle physico-chemical properties with special focus on physical parameters such as size distribution, volatility, effective density, fractal dimension, surface area etc. Particle effective density and fractal dimensions were measured near a gasoline and a mixed freeway with significant diesel fleet. Diesel vehicles emit higher fraction of low density chain agglomerates compared to gasoline vehicles. Particle density at a receptor site showed interesting diurnal trend with peaks during sunny afternoons. Overall, particles demonstrated an inverse relation between size and density. Particle volatility, an important parameter to infer exposure to commuters, was measured near a pure gasoline and diesel dominated mixed-traffic freeway. Diesel particulates were associated with higher content of non-volatiles than those generated from gasoline engines and correlated excellently with the refractory elemental carbon emissions. Particle mixing characteristics not only depend on the fleet composition but also on environmental factors. Thus, to investigate the effect of meteorological conditions on particle characteristics experimental campaigns were designed to capture seasonal and diurnal variability. Although the daytime seasonal influences on particle volatility were minimal, strong diurnal changes were observed during winter. Finally, the physical characteristics of particles from diesel vehicles retrofitted with advanced emission control technologies were determined by controlled studies with a dynamomter set-up. These after treatment devices were efficient in removing solid particles, but were less effective in controlling volatile species which formed fresh nucleation mode particles. Particle volatility, density, surface diameter and extent of agglomeration were determined and compared with respect to a baseline vehicle. Our results indicate that vehicles with strong nucleation mode particles are associated with higher volatility and density and lower agglomeration.Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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MODELING AND SIMULATION OF MULTIPHYSICAL PROCESSES IN PARTICULATE MEDIA
Wed, Feb 20, 2008 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Dr. Tarek Zohdi, California State University-BerkleyAbstract:
Recently, several applications, primarily driven
by micro-technology, have emerged where a successful
analysis requires the simulation of flowing particulate media involving simultaneous near-field interaction between charged particles and momentum exchange through mechanical contact. For example, industrial processes such as Chemical Mechanical Planarization (CMP), which involves using chemically-reacting particles embedded in fluid (gas or liquid) to ablate rough small-scale surfaces flat, have become important for the success of many micro- and nano- technologies. Charged material can lead to inconsistent ``clean'' manufacturing processes, for example, due to difficulties with dust control, although intentional charging of particulate material can be quite useful in some applications, for example involving electrostatic copiers, inkjet printers, powder coating machines, etc. The presence of near-field interaction forces can produce particulate flows that are significantly different than purely contact-driven scenarios. The determination of the dynamics of such materials is important for the accurate description of the flow of powders, which form the basis of micro-fabrication. Near-field forces can lead to particle clustering, resulting in inconsistent fabrication quality.
Therefore, neglecting such near-field effects can lead to a gross miscalculation of the characteristics of such flows.
Thus, an issue of overriding importance to the successful characterization of such flows is the development of models and reliable computational techniques to simulate the dynamics of multibody particulate systems involving near-field interaction and contact simultaneously (including thermal effects).Ideally, in an attempt to reduce laboratory expenses, one would like to make predictions of a complex particulate flow's behavior by numerical
simulations, with the primary goal being to minimize time-consuming
trial and error experiments. A central objective of this presentation is to provide basic models and numerical solution strategies for the direct simulation of flowing particulate media that can be achieved within a relatively standard desktop or laptop computing environment. Also, if time permits, the closely related topic of ``swarms'' is discussed.
The topics to be touched upon are:(1) Particulate flows(2) Related problems in swarm modeling(3) Optical (electromagnetic energy) propagation(4) Acoustical (mechanical energy) propagation(5) Degradation/aging of particulate continua and(6) Related problems in electromagnetic materialsLocation: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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A Co-rotational Kinematic Framework for Large Deformation Analysis
Wed, Feb 27, 2008 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Dr. Arif Masud, Department of Civil and Environmental Engineering, The University of Illinois at Urbana-ChampaignThis talk presents a hierarchical approach to the modeling of multi-layered composites with arbitrary ply lay-up sequences and orientations. The approach is applicable to flat as well as curved geometric configurations. The model is based on a co-rotational procedure that is derived consistently from the updated Lagrangian framework. The underlying variational formulation is based on an assumed strain method. Displacements and rotations are assumed finite while the strains are infinitesimal. The close relationship between the co-rotational procedure and its underlying updated Lagrangian framework is presented to highlight the cost reduction for large and complicated geometric configurations. Some simple but mathematically consistent procedures for updating element stresses and calculating the internal force vector are also discussed.
An elastoplastic damage model is incorporated in this co-rotational framework to accommodate material degradation in each individual laminate. The model is based on irreversible thermodynamics with the damage surface defined in terms of an internal damage variable of energy, along with a set of rate-independent elastoplastic constitutive equations that are defined in an effective stressâ€"strain space. Employing the operator splitting methodology, a three-step predictor/multi-corrector algorithm is developed that includes an elastic predictor, a plastic corrector, and a damage corrector.
Several representative numerical simulations of materially and geometrically nonlinear analysis are presented to show the accuracy and the range of applicability of the model. The model is then applied to the design of a co-axial laminated system.Vita: Professor Arif Masud received Ph.D. in Computational Mechanics from Stanford University in April 1993. He joined the University of Illinois at Urbana-Champaign in August 2006, after having served on the faculty of University of Illinois at Chicago from 1994-2006. Dr. Masud is working on the development of multi-scale finite element methods for application in nonlinear solid and fluid mechanics. He has delivered several Keynote Lectures at International Conferences, and organized more than ten International Symposia on Multiscale & Stabilized Finite Element Methods. He is co-editor of the book The Finite Element Method: 1970s and Beyond that appeared in 2004. In 1999 he was awarded the Teaching Recognition Award by the Council for Excellence in Teaching at UIC, and in 2002 he was awarded the Faculty Distinguished Research Award by the College of Engineering at UIC. Dr. Masud serves on the Editorial Boards of five International Journals. He is Chair of the Computational Mechanics Committee of ASCE, and Vice-Chair of the Fluid Mechanics Committee of ASME. Dr. Masud serves as an Associate Editor of the ASCE Journal of Engineering Mechanics, and an Associate Editor of the ASME Journal of Applied Mechanics. In 2006 he was elected Fellow of the International Association of Computational Mechanics (IACM).
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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EFFICIENT INTEGRATION OF NONLINEAR SITE RESPONSE
Thu, Feb 28, 2008 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Dominic Assimaki-Professor
School of Civil and Environmental Engineering - Georgia TechABSTRACT:
While the quantification of site effects is of great significance in seismic hazard mitigation, there currently exists a large degree of uncertainty concerning the mathematical model to be employed for the efficient evaluation of these effects, and the site investigation program for evaluation of the associated input parameters. Towards the development of a comprehensive framework for credible and efficient integration of site response predictions in rupture scenaria simulations that addresses these issues, we here combine downhole observations and broadband ground motion synthetics for characteristic profiles in the Los Angeles Basin, and investigate the variability in ground motion introduced by the site response assessment methodology and uncertainty in nonlinear model parameter description. Regional velocity and attenuation structures are initially compiled using geotechnical data and the crustal velocity structure at three sites in Southern California. Broadband ground motion simulations are next conducted for scenaria of weak, medium and large magnitude events, and three component seismograms are computed on a surface station grid at distances 1km-75km from the surface projection of the fault. Elastic, equivalent linear and nonlinear site response simulations at multiple levels of complexity are then evaluated, and the coefficient of variation (COV) of site amplification factors is evaluated, defined as the ratio of the predicted peak ground acceleration (PGA) and spectral acceleration (SA) at short and long periods to the corresponding ground motion intensity measure on rock-outcrop. A frequency index is developed to identify the site conditions and ground motion characteristics where the high COV of free-field response implies that incremental nonlinear analyses should be employed in lieu of approximate methodologies. Next, the parametric uncertainty of nonlinear models is assessed by defining fixed- and free-parameters for each model and systematically randomizing the latter. Results show that site nonlinearity susceptibility and optimal nonlinear model complexity may be quantified by the proposed intensity-frequency index pair representation of site conditions and ground motion characteristics, while development of the target generalized computational framework for site response analyses is conditioned on the collection a statistically significant number of ground motion observations and synthetics at a wide spectrum of site conditions.Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Monitoring Water for People Projects in Malawi
Fri, Feb 29, 2008 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Environmental Engineering Seminar:Joyce.T.Lee,
Environmental Engineer,
MWH Americas, Inc.,
Arcadia, CA 91007AbstractWater For People has been working in Malawi since 2000, helping to provide more than 150,000 people with safe drinking water and/or improved sanitation. As part of a WFP Water Corps Team, Joyce T. Lee recently conducted a Monitoring Study in Malawi. The study involved follow-up research on previously installed water and sanitation projects funded by Water for People including borehole wells, hand-dug shallow wells, Afridev hand pumps, rainwater catchment tanks, community tap stands and pit latrines. The team conducted water committee and user interviews, reviewed operations, data and revenue collection, sanitation and hygiene education. Data were entered into the Water for People database for future site monitoring and follow-up. A complete report from the monitoring study should be available shortly on the Water for People website. During this talk, Joyce shares her experience as a member of the team that conducted the 2007 Monitoring Study in Malawi.
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
