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Events for April
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Seminar: Fate and Transport of nano-TiO2 in Aquatic Environments
Mon, Apr 25, 2011 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Sharon L. Walker Associate Professor and the John Babbage Chair in Environmental Engineering University of California Riverside,
Abstract: Fate and transport of nanoparticles in aquatic environments have been investigated utilizing nano-TiO2, as it is one of the most widely used nanomaterials in industry. The project was developed to identify the fundamental mechanisms involved in the transport of nano-TiO2 and the contribution of various environmental parameters including solution chemistry (pH, ionic strength, and ion valence), hydrodynamic effects, and the presence of natural organic matter(NOM). Complementary transport studies have been conducted in both macroscopic (packedbed column) and microscopic (parallel plate flow cell) systems. Additionally, extensive
physical-chemical characterization of the nanoparticles was conducted under these various solution conditions. The combination of these transport and characterization tools has
demonstrated the critical role that pH, ionic strength and valence, NOM, and aggregation state play in the transport. Results from both transport systems and particle characterization will be presented, as well as the proposed transport and retention mechanisms observed. Additionally, a
brief overview of Walkerâs research in bacterial pathogen fate and transport will be discussed as well.
Biography: Sharon Walker received her Ph.D. in Environmental Engineering, from the Department of Chemical Engineering at Yale University in 2004. She earned her M.S. in Chemical and Environmental Engineering from Yale in 2000 and two Bachelor of Science degrees from the University of Southern California in Environmental Engineering and Environmental Studies in 1998. She is a member of the American Chemical Society (ACS), American Institute of Chemical Engineers (AIChE), American Society of Microbiology (ASM), Association for Environmental Engineering and Science Professors (AEESP), Air and Waste Management
Association (AWMA), Association of Women in Science (AWIS), and Society of Women Engineers (SWE). She is also a member of Chi Epsilon and Tau Beta Pi. She is currently a faculty advisor to the UC Riverside Alpha Beta chapter of Tau Beta Pi and campus chapter of SWE. She was awarded the 2010 NSF Career Award and she was a Fulbright Scholar at Ben Gurion University of the Negev in Israel during the 2009-2010 school year.
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Oral Defense Dissertation: Enabling Geotechnical Data for Broader Use by the Spatial Data Infrastructures
Mon, Apr 25, 2011 @ 03:00 PM - 05:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Amir Zand, Civil Engineering Ph.D. Candidate,
Abstract: Geotechnical data is one of the most prevalent data types in civil engineering projects. Majority of the civil engineering projects that are in use today are designed using site-specific geotechnical data.
The usage of geotechnical data is not limited to construction projects. This data is used in a wide range of applications, including seismic hazard analysis, planning and zoning studies, risk analysis and other infrastructure development projects. Demand for geotechnical data in this type of applications has increased in the past few decades, due to proliferation of geographic information systems (GIS) and variety of applications that take advantage of GIS and spatial data.
Considering the widespread collection and usage of geotechnical data in various disciplines, one might expect that this data is readily available for most developed areas. However, unlike other types of spatial data that are available in spatial data infrastructures (SDI), geotechnical data is often managed using traditional and ineffective methods. Consequently, for a lot of projects it is difficult to find and acquire this data. This issue is frequently encountered in civil engineering projects, and more importantly, in large-scale multi-disciplinary studies that need large volumes of geotechnical data.
In order to address this problem, the current methods used for management, archiving and distribution of geotechnical data need to be improved upon. The most viable solution is to leverage the existing information technology infrastructure and adopt the methods that are already in use for other types of spatial data. These technologies include geography markup language (GML), spatial databases and web services developed for spatial data exchange.
Following this concept, in the subject dissertation development of a spatial data model for geotechnical data is discussed. The discussion includes an overview of the geotechnical data collection, processing and current methods that are used to archive and exchange this data. The proprietary software and data formats that are used for geotechnical data exchange, including the association of geotechnical and geoenvironmental specialists (AGS) data format, are covered in this review. In addition, the current state of information technology for other types of spatial data is evaluated. This background study includes spatial databases, spatial data infrastructures and various standards that are adopted by the industry and regulating agencies for management and dissemination of spatial data.
Based on this framework, a data model is proposed for integration of geotechnical data in SDIs. This data model uses the terminology of the AGS geotechnical data exchange format, and combines it with a GML-conformant schema. GML is the industry-standard markup language for modeling spatial data for use in SDIs.
The developed data model is compared with similar proposals from other research groups. The functionality of the data group is verified using several examples involving visualizing the geotechnical data, and using it for analyses such as site response analysis and liquefaction hazard assessment. A case study is presented which demonstrates the potential benefits of these analysis scenarios in real-world studies.
Finally, the achievements of the dissertation are summarized and suggestions are made in order to improve the results of the current study. Also, some related research topics are suggested to continue and further expand the concepts presented in this dissertation.
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Defense Dissertation: Prediction of Extreme Events in Southern California
Thu, Apr 28, 2011 @ 02:00 PM - 04:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Bennington J. Willardson, Ph.D. Candidate, Civil and Environmental Engineering
Abstract: The prediction of extreme runoff events has significant risk and financial implications when dealing with hydraulic infrastructure. This is especially true in highly urbanized areas such as Southern California. Two methods for determining extreme runoff exist: extrapolation of existing runoff data using extreme event probability distributions, or hydrologic modeling using design rainfall events and watershed characteristics to generate an estimate of the extreme runoff event. This research investigates both methods to evaluate usefulness and limitations in providing guidance for risk and financial analysis.
Design of levees and flood protection channels often focuses on providing protection from events with a 50- to 100-year recurrence interval. In many areas of the country, stream gage record sets do not contain records of this length. The effects of record length, probability distribution selection, and the method of parameter estimation are evaluated to determine the impacts on prediction of the extreme runoff event used for levee and channel design.
Design storms are often used with hydrologic models to predict runoff for events larger than those measured through systematic stream gaging. The Probable Maximum Precipitation (PMP) - Probable Maximum Flood (PMF) methodology is widely used. This research evaluates the use of this standard on design for major hydraulic structures such as dam spillways within Southern California. Two standard PMP methodologies are evaluated based on rain gage frequency analysis within Los Angeles County. The effects of soils, watershed characteristics, and wild fire on extreme runoff events are also evaluated using Monte Carlo Simulation of 27 watersheds within the County.
The Monte Carlo Simulations evaluates two design storms, two soil loss methodologies, and the effects of fire within a watershed. The structure and development of the model will be discussed, as well as the results for the different cases in determining extreme runoff events. Conclusions will be drawn regarding prediction of extreme runoff events in Southern California.
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Oral Defense Dissertation: Chromium Remediation in Groundwater Using Integrated Microbial Fuel Cells and Electrokinetic Systems
Fri, Apr 29, 2011 @ 01:00 PM - 04:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Lewis Hsu, Environmental Engineering Ph.D. Candidate
Abstract: Hexavalent chromium (CrVI) is a common metallic carcinogen heavily used in industrial applications such as electroplating and leather tanning. Improper handling and disposal, along with the high solubility of CrVI, have led to widespread contamination of soil and water systems. Several remediation methods have been proposed, including biologically based techniques.
Bioremediation of CrVI is a promising approach due, in part, to the ability of the technique to rapidly lower CrVI concentrations. The research presented here focuses on the development of a CrVI remediation approach based on microbial fuel cell (MFC) technology. MFC technology has been proposed as a source of renewable energy and as a remediation tool. While much work has been done on developing the technology as a renewable energy source, relatively little work has been performed to assess its capabilities as a remediation tool.
To address this shortcoming, the research presented here will showcase several aspects of using an MFC as a remediation tool. These include (i) a predictive modeling approach for biological CrVI remediation, (ii) an evaluation of Shewanella bacteria as biocatalysts, (iii) the selection and analysis of mixed communities in a CrVI-reducting MFC, and (iv) the integration of a CrVI-reducing MFC with an electrokinetic system.
These findings show that CrVI removal to low parts-per-billion concentration levels is possible with MFC systems and that integration with existing technologies is a valuable application to consider when designing remediation strategies.
Location: Charles Lee Powell Hall (PHE) - 333
Audiences: Everyone Is Invited
Contact: Evangeline Reyes