Conferences, Lectures, & Seminars
Events for April
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Length and Time Scales of Trapping Processes Associated with CO2 Sequestration
Wed, Apr 02, 2008 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Dr. Hamdi Tchelepi, Stanford University Abstract:
We study the primary CO2 trapping processes in deep saline aquifers:
dissolution and residual trapping. The length and time scales associated with the onset of miscible instability and the long term convective dissolution rates are analyzed using linear stability analysis and high-resolution nonlinear simulations. The migration of CO2 plumes as gravity currents and the effect of residual trapping of the CO2 in the wake of the advancing current are analyzed using a one-dimensional sharp-interface model. We study the behavior of gravity currents in large-scale aquifers with small dip angles, and we discuss issue related to propagation speeds, trapping capacities, and maximum plume migration distances. These preliminary results indicate that CO2 storage in large, deep saline aquifers may be a viable option.Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Interm-scale Testing for Process Understanding, Model Validation & Up-scaling of Flow &Trans
Fri, Apr 04, 2008 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Tissa Illangasekare, PE, DEE, DWREAMAX Distinguished Chair of Environmental Sciences and Engineering
And Professor of Civil Engineering
Director, Center for Experimental Study of Subsurface Environmental Processes (CESEP)
Colorado School of Mines, Golden, Colorado, USAABSTRACTGeologic heterogeneity plays a significant role in water flow and complex behavior of chemicals and waste products in the subsurface. A complete knowledge of the governing processes and how they are affected by the heterogeneity are difficult to obtain at field sites due to cost constraints and limitations of currently available technologies and methods for subsurface characterization. Characterization data limitations and lack of access and control at field sites make it difficult to validate theories and prediction models simulating complex flow and transport processes. Intermediate-scale, physical models provide cost effective alternatives that allows for the generation of accurate and high-resolution data at a range of observational scales, under controlled conditions in synthetically created aquifers that are highly instrumented for automated data acquisition. Examples involving numerical and conceptual model validation, soft and hard data assimilation in model calibration, evaluation of remediation technologies, up-scaling from laboratory to field systems and development of new sensor technologies for subsurface monitoring will be presented.Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Application of Omics-Based Tools and Microarrays to Optimize Bioremediation
Wed, Apr 09, 2008 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Lisa Alvarez-Cohen
Professor and Chair of Civil and Environmental Engineering Department, UC Berkeley This talk will focus on the application of omics-based molecular tools to understand and optimize the bioremediation of environmental contaminants by naturally occurring microorganisms. Bioremediation is a process that often relies upon mixed microbial communities to catalyze important biodegradation pathways. In order to improve our understanding of bioremediation processes, there is a need to develop rapid, quantitative, non-culture based molecular and microbiological assays for use in characterizing microbial communities and activities in subsurface soils. This talk will describe a variety of detection and quantification techniques applied to both genes and transcripts of interest, including quantitative PCR (qPCR), reverse transcription qPCR and whole-genome microarrays for comprehensive comparative genomics and transcriptomics with subsequent confirmation by proteomics. In addition, application of phylogenetic microarrays for identification of specific organisms in complex communities will be described. We have applied these tools to both laboratory samples for fundamental research, and to field samples for applied research in bioremediation of conventional and emerging contaminants.Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Low-Cost High-Efficiency Distributed Hydrogen Production for Combined Heat and Power
Fri, Apr 11, 2008 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Dr. Durai Swamy, Intelligent Energy, Inc.Intelligent Energy is developing a new-generation 1-10 kWe CHP unit that achieves the high efficiency, high durability and low cost targets simultaneously includes a bold optimization and integration of existing IE technology platforms. The CHP unit will be based on IE's open architecture integration philosophy that maintains a high purity hydrogen interface between the hydrogen generation and fuel cell subsystems. The fuel cell subsystem will be derived from IE's 2kWe CHP platform and its advanced 10kWe auxiliary power unit platform that achieves 60% efficiency on pure hydrogen. An innovative hydrogen generation subsystem will be developed to support the aggressive costs and performance targets, but will leverage IE's experience from two validated technology platforms: - IE's 100 to 500We membrane reformer that achieves 99.9+% purity on seven different fuel types, and its 10kWe steam reformer integrated with a fast cycle pressure swing adsorption hydrogen purification system. Both of these H2 generation platforms achieve only efficiencies in the range of 60-65% currently. IE plans to investigate significant improvements in these technologies to increase the H2 generation efficiency over 75%.
The greatest challenge of the development will be to achieve an optimized balance between increased stack performance (high cell voltage at high current densities), low cost cell components, increased hydrogen generation efficiency (high fuel conversion, lower steam/carbon ratios, maximum recuperation of heat and water vapor, and high hydrogen recovery factors), low parasitic power components and efficient grid connected inverter, and least cost balance of plant in a fully integrated system.
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Multiscale computations for flow and transport in heterogeneous porous media
Wed, Apr 16, 2008 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Dr. Tom Hou, Charles Lee Powell Professor, Caltech Abstract: Many problems of fundamental and practical importance contain multiple scale solutions. Composite materials, flow and transport in heterogeneous porous media, and turbulent flow are examples of this type.
Direct numerical simulations of these multiscale problems are extremely difficult due to the wide range of length scales in the underlying physical problems. In this talk, I describe some of our recent efforts in developing multiscale computational methods to upscale two-phase flows in strongly heterogeneous porous media. For some challenging problems with long range scale interaction arising from engineering applications, we show how to use limited global information to improve the accuracy of the multiscale method. Another important application is how to quantify uncertainty in modeling the heterogeneous random media. We show that by using a coarse multiscale model to precondition the Markov Chain Monte Carlo method, we can significantly improve the efficiency of the MCMC method in generating the probability distribution of the random media subject to some production data. Finally, we introduce a new multiscale analysis for convection dominated incompressible flow with multiscale solutions. Our multiscale analysis provides an important guideline in designing a multiscale method for computing incompressible flow with multiscale solutions.Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Stimulating the indigenous microorganisms to remove heavy metals from marine sediments
Fri, Apr 18, 2008 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Jinjun KanDepartment of Earth Sciences
University of Southern California
Los Angeles CA 90089Microbial activities play critical roles in metal remediation in natural environments. Adding organic or inorganic amendments will stimulate growth of indigenous microorganisms and then the microbes contribute to sorb, degrade, transform or immobilize metals from the environments. In this current study, we evaluated microbial stimulation of adding inorganic (e.g. apatite) and organic (e.g. chitin, acetate) amendments to marine sediments. Significant bacterial biomass and activities were induced by amendments of apatite, chitin and acetate. Molecular fingerprints of bacterial communities by denaturant gradient gel electrophoresis (DGGE) showed that distinct bacterial populations occurred in different amendments, and the stimulated microorganisms contained three major bacterial groups, Alphaproteobacteria (Roseobacter), Gammaproteobacteria and Bacteroidetes. Alphaproteobacteria (Roseobacter) dominated in water columns while Bacteroidetes were predominant population in the sediments. Most probable number (MPN) analyses showed that sulfate-reducing bacteria were significantly induced in the treatments with chitin, apatite+chitin. Testing N-acetylglucosamine and acetate as potential carbon source has also recovered sulfate-reducing bacteria. Sulfide-producing and metal-reducing bacteria were also recovered by using thiosulfate as an electron-acceptor. The results indicate that amendments stimulate geochemically important bacteria and further investigations on their physiological properties are critical to recognize their actual roles in the metal remediation process.Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Green Campus and Education for Sustainability
Thu, Apr 24, 2008 @ 02:00 PM - 03:30 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Al Dorman Distinguished Lecture Series
Speaker: Dr. Jean-Lou Chameau President, Caltech Click link for further information:
http://viterbi.usc.edu/news/events/keynote/dorman/Location: Ronald Tutor Hall of Engineering (RTH) - 526
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Model, Identification & Analysis of Complex Stochastic Systems:
Fri, Apr 25, 2008 @ 11:00 AM - 01:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Sonjoy Das- PhD DefenseThe work presented in this dissertation focuses on characterization, identi¯-cation and analysis of stochastic systems. Stochastic systems refer to a physical
phenomena with inherent uncertainty in it, and are generally characterized by
two forms of representation: (1) a governing conservation law or partial dif-ferential equation (PDE) with some of its parameters interpreted as random
processes, and (2) a model-free random matrix operator. In this work, three
data-driven approaches are ¯rst introduced to characterize and construct consis-tent probability models of non-stationary and non-Gaussian random processes
or ¯elds within the polynomial chaos (PC) formalism. The resulting PC rep-resentations would be useful to probabilistically characterize the system input-output relationship for a variety of applications. Second, a novel hybrid physics-and data-based approach is proposed to characterize a complex stochastic sys-tems by using random matrix theory. Application of this approach to multiscale
mechanics problems is also presented. Also discussed in this work is a simple,
computationally e±cient and experiment-friendly coupling scheme based on fre-quency response function. This coupling scheme would be useful for analysis of
a complex stochastic system consisting of several subsystems characterized by,
e.g., stochastic PDEs or/and model-free random matrix operators.Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Role of ammonia and water vapor on the formation of secondary organic aerosols in alkene/ozone react
Fri, Apr 25, 2008 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Dr. Kwangsam NaBourns College of Engineering¡XCenter for Environmental Research and Technology (CE-CERT), University of California, RiversideAbstractThis study deals with the influence of ammonia (NH3) on secondary organic aerosol (SOA) formation from the Ñ-pinene/ozone systems in the dry and humid conditions. The effect of different OH scavengers on SOA formation is briefly described. The aerosol yield differed depending on which OH scavenger was used. Yield was the highest using CO, followed by cyclohexane and 2-butanol. It was found that the number and volume concentrations were quickly increased by 15% and 8%, respectively when NH3 was added after the reaction ceased. An increase in number concentration indicates the formation of new particles resulting from gas-to-particle conversion. Moreover, average size of particles increased from 242 nm to 248 nm. The resulting particles may be ammonium salts formed by the reaction between organic acids and NH3. When NH3 was added to an aerosolized cis-pinonic acid in the chamber reactor, a dramatic increase in both number and volume concentrations of cis-pinonic acid was observed. This is evidence that NH3 drives gas-phase organic acids into condensable salts, leading to elevated SOA formation. Initially present NH3 significantly enhanced aerosol yield in Ñ-pinene-ozone reactions, regardless of the presence of water vapor. However, the enhancing effect of NH3 on SOA formation was found to diminish in humid conditions. The degree of the increase in SOA yield in the presence of NH3 was higher in the humid condition than in the dry condition. The role of NH3 on SOA formation in the dry and humid conditions was further explained and discussed in terms of a theoretical modeling study.
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Understanding Solute Transport in Extremely Heterogeneous Subsurface Media: A Field Perspective
Mon, Apr 28, 2008 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Dr.Chunmiao Zheng- Department of Geological Sciences, University of AlabamaField studies at well-instrumented sites have played a preeminent role in our efforts to better understand and characterize solute transport processes in geologic media. In particular, several field tracer tests conducted at well-known sites such as those in Borden, Canada (MacKay et al., 1986), Mobile, Alabama (Molz et al., 1986), Twin Lake, Minnesota (Killey and Moltyaner, 1988), Cape Cod, Massachusetts (LeBlanc et al., 1991) and Columbus, Mississippi (Boggs et al., 1992) have provided new insights and extensive data sets for development and testing of transport theories and mathematical models. This presentation focuses on the Columbus, Mississippi site, more commonly known as the Macrodispersion Experiment (MADE) site.
Since the 1980s, three large-scale natural-gradient tracer tests and other types of field studies have been conducted at the MADE site located inside the Columbus Air Force Base in Mississippi, southeastern United States. The field data from the MADE site have been used extensively by researchers around the world to investigate and understand contaminant transport processes in highly heterogeneous aquifers. The MADE site has directly or indirectly inspired the development of a number of new and improved theories and computer models aimed at more accurate representation and prediction of contaminant transport affected by extreme aquifer heterogeneity. A great deal of recent and on-going research on contaminant transport in heterogeneous media has been motivated by the findings from the MADE site that suggest the existence of preferential flow paths resulting from small-scale heterogeneities. Since the 1980s, three large-scale natural-gradient tracer tests and other types of field studies have been conducted at the MADE site located inside the Columbus Air Force Base in Mississippi, southeastern United States. The field data from the MADE site have been used extensively by researchers around the world to investigate and understand contaminant transport processes in highly heterogeneous aquifers. The MADE site has directly or indirectly inspired the development of a number of new and improved theories and computer models aimed at more accurate representation and prediction of contaminant transport affected by extreme aquifer heterogeneity. A great deal of recent and on-going research on contaminant transport in heterogeneous media has been motivated by the findings from the MADE site that suggest the existence of preferential flow paths resulting from small-scale heterogeneities. This presentation will provide an overview of the research activities at the MADE site over the past 25 years and discuss how the findings from field studies have motivated various theories and models purported to accommodate so-called non-ideal transport behavior observed at the MADE site. Of particular interest are our recent field campaigns to further test the hypothesis that solute transport at the MADE site is dominated by small-scale preferential flow paths. These field campaigns include forced-gradient tracer tests, soil coring, direct-push hydraulic profiling, and high-resolution resistivity and GPR surveys. The on-going efforts are aimed at building stronger theoretical underpinnings and useful practical tools for modeling solute transport and for designing remedial measures in extremely heterogeneous aquifers such as that encountered at the MADE site.Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Environmental Engineering for Los Angeles County
Wed, Apr 30, 2008 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Alex Mena & Mike Sullivan- Los Angeles County Sanitation DistrictsAbstract:
The Sanitation Districts of Los Angeles County (Districts) lead a regional movement towards environmental sustainability in California by converting waste to vital resources such as water and energy. The Districts have been providing wastewater and solid waste management since the late 1920's, and have been expanding renewable energy recovery options at every opportunity. The Districts currently provide these services for over five million people, and have an average annual budget that exceeds $1 Billion. Facilities include: over 1,300 miles of sanitary sewers; eleven wastewater treatment plants treating over 500 MGD; a reclaimed water reuse program serving over 500 sites directly, as well as replenishing groundwater; three active sanitary landfills handling a total of approximately 20,000 tons per day, including the largest landfill in the nation; three materials recovery facilities/transfer stations; and multiple energy production facilities, generating over 127 Megawatts. Energy recovery operations provide enough renewable energy to power 150,000 homes. The Districts are consistently nationally ranked in the top 3 of the "Top 10 Local Government" Green Power Partners selected by the EPA and are the 20th largest producer of electrical power in California.
If you have more space....Innovative projects in progress include design and construction of a regional 2,800 acre landfill that will accept 100 years of solid waste via rail transport, and the largest indoor and outdoor biosolids composting facilities in the country. The Districts are currently investigating the environmental benefits of constructing a new ocean outfall. If constructed, the $1-2 Billion outfall project would represent one of the most challenging and high profile public works projects in the nation. Engineers are involved in all phases of our work, from conception to operation. Almost all engineering is performed in-house, and the majority of Districts engineers have graduate degrees in civil/environmental engineering. Over 250 Districts engineers work in areas such as: research, air and water quality monitoring, design, geotechnical engineering, hydrogeology, planning, construction, operations, industrial waste, and financial management as well as the specialty areas of electrical, instrumentation, mechanical, and structural engineering.Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes