Conferences, Lectures, & Seminars
Events for March
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Astani CEE Oral Defense
Mon, Mar 03, 2014 @ 11:00 AM - 01:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Armen Derkevorkian , Astani CEE Ph.D. Student
Talk Title: Studies into Data-Driven Approaches for Nonlinear System Identification, Condition Assessment, and Health Monitoring
Abstract:
The recent advancements in computational capabilities and sensing technologies provide an excellent opportunity to develop, test, and validate data-driven mathematical models for system identification, condition assessment, and health monitoring of structural systems that may be vibrating in linear and/or nonlinear ranges. In this study, measurements from various large-scale, complex, experimental systems, as well as full-scale real-life multi-input-multi-output (MIMO) structures are used to develop robust mathematical frameworks for response prediction, change detection, nonlinear damping estimation, in addition to displacement-field and operating-load estimation. The systems under consideration are the Yokohama Bay Bridge which was subjected to the 2011 Great East Japan Earthquake; large-scale experimental soil-foundation-superstructure interaction systems subjected to various earthquake excitations with systematically increasing levels of intensity; swept wing-like experimental aluminum plates developed at the NASA Dryden Flight Research Center and instrumented with state-of-the-art fiber-optic sensors; and a four-story experimental test-bed designed, developed and fabricated at the University of Southern California. The vibration signatures from these systems are used to assess the viability of existing parametric and nonparametric identification approaches, and to propose new hybrid data-driven computational modeling methods that can accurately capture the correct physics of the underlying complex systems. This dissertation is a collection of analytical, computational, and experimental studies that capitalizes on the availability of large datasets to develop tools that can interpret these datasets, and to establish robust frameworks that can extract physically meaningful information, for an informed decision-making.
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Astani CEE Department Seminar
Tue, Mar 04, 2014 @ 10:00 AM - 11:00 AM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Ngai Yin Yip, Yale University
Talk Title: Harnessing Natural Salinity Gradients for Sustainable Power Generation with Pressure Retarded Osmosis
Abstract: The development of alternative power sources is necessary to enable a global shift to a sustainable energy future. Pressure retarded osmosis (PRO) can produce renewable energy from natural salinity gradients by harvesting the free energy of mixing released when fresh river water or brackish water combines with seawater. This presentation will discuss the potential of sustainable power generation with natural salinity gradients, the recent membrane advancements toward realization of the technology, and the challenges that can hinder the implementation of PRO energy production. Firstly, a thermodynamic and energy analysis of PRO is presented to identify the intrinsic limitations and determine the efficiency of the process. The findings are then employed to assess the global potential of power generation with natural salinity gradients. In the second part of the study, the fabrication of thin-film composite membranes capable of achieving high performance in PRO is demonstrated. By thoughtful selection of the fabrication conditions to methodically suppress the detrimental effects that limit productivity, the hand-cast membranes advanced the achievable power densities to ~10 W/m2, twice the benchmark necessary for the technology to be cost-effective. Lastly, the detrimental impact of membrane fouling in PRO is examined and the cleaning efficiency of a quick, chemical-free osmotic backwash is evaluated. The fouling phenomenon and cleaning protocol were systematically analyzed and the implications for PRO power generation with natural salinity gradients are discussed.
Biography: Ngai Yin Yip is a doctoral student in the Department of Chemical and Environmental Engineering at Yale University. He received his bachelor's degree in Environmental and Civil Engineering (First Class Honors) from Nanyang Technological University, Singapore. His dissertation work focuses on novel membrane technologies for the sustainable production of energy and water. He received the ACS Environmental Chemistry Graduate Student Award in 2011 and the C. Ellen Gonter Best Paper Award from ACS in 2013.
Host: Astani CEE Department
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Cassie Cremeans
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Astani CEE Ph.D. Seminar
Fri, Mar 07, 2014 @ 04:00 PM - 05:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Pedram Oskouie, Astani CEE Ph.D. Students
Talk Title: A framework for automated monitoring and movement analysis of highway retaining walls using 3D laser scanners
Abstract: The architecture engineering and construction (AEC) industry has adopted innovative and novel alternative methods to ensure faster, more economical, and higher quality project delivery. Recently, there has been an increase in the use of laser scanners in the industry to create as-built models for accurate (millimeters) and rapid assessment of progress, productivity, and quality assurance. As part of this research, the data from an ongoing highway construction project are processed and analyzed. The project uses 3D laser scanners for regular monitoring of mechanically stabilized earth (MSE) walls that retain the soil supporting the highway alignment. In order to start up processing the generated point clouds (3D as-built points), the accuracy of scans in terms of capturing all the geometrical features and details has to be verified. Additionally, the point clouds have to be cleaned from unwanted objects as well as noises. Once the point clouds are pre-processed, the vertical settlements and lateral displacements of the walls are calculated by comparing point clouds from different dates. This research aims to fill the current research and practice gaps by (1) Defining an automated scan plan and data collection framework to minimize scanning and point cloud registration- related errors (2) Defining an automated point cloud cleaning and noise removal process (3) Improving the quality and efficiency of change detection and movement analysis using 3-D laser scanners.
Location: John Stauffer Science Lecture Hall (SLH) - 102
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Astani CEE Department Seminar
Mon, Mar 10, 2014 @ 11:00 AM - 12:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Debora F. Rodrigues , University of Houston
Talk Title: Environmental Engineering Implications and Applications of Carbon-Based Nanomaterials
Abstract: Carbon-based nanomaterials, such as carbon nanotubes, graphene, and graphene oxide, have unique antimicrobial, physical, chemical, electrical, optical and mechanical properties that make them very valuable materials for materials science, high-energy physics, and a wide range of technological applications. In fact, the market for carbon-based nanomaterial products is projected to reach nearly $675 million by 2020, hence it is expected that large quantities of graphene-based wastes will be generated by then. If nanomaterials are to be widely utilized, they will find their way into the environment through human activities, wastewater discharge, industrial effluents, and runoff from nearby contaminated land. Aquatic systems are expected to be the ultimate repository for nanomaterials, which poses a special concern because aquatic systems are composed of diverse microorganisms that keep the aquatic environment ecologically balanced. These microorganisms are also responsible for removing unwanted wastes released into the wastewater treatment system through various biogeochemical cycles, such as nitrogen, phosphorous, sulfur, and carbon cycles. The theme of my research is to understand the toxicological mechanisms and effects on microbial biogeochemical cycles of emerging graphene-based nanomaterials. Additionally, I investigate alternative solutions to reduce the use of these nanomaterials, and therefore reduce their release into the environment. The approach used by my research group is the utilization of polymers, such as polyvinyl-N-carbazole (PVK), to develop nanocomposites that contain small amounts of carbon-based nanomaterials as fillers. The PVK polymer was selected to generate carbon-based nanocomposites since it stabilizes the dispersion of the nanomaterials in any solution chemistry due to the ( ) stacking interaction of the PVK carbazole group with the aromatic rings of the carbon-based nanomaterials. The well-dispersed nanocomposite can, then, be easily used to modify membranes for water purification. These modified membranes are much more effective in the inactivation and removal of viruses and bacteria from water than unmodified ones.
Biography: Debora F. Rodrigues received her BS and MS in Biology and Microbiology, respectively, from the University of Sao Paulo, Brazil, and her PhD in Microbiology and Molecular Genetics from Michigan State University in 2007 under the supervision of Prof. James Tiedje. In her MS research she demonstrated the presence of genes involved in the degradation of polychlorinated biphenyls (PCBs) and hydrocarbons in Brazilian estuaries. Her PhD work focused on the physiology and diversity of microorganisms in the Siberian permafrost. She was a postdoctoral associate in the Environmental Engineering Program at Yale University in the group of Prof. Menachem Elimelech from 2007 to June 2010. Her research at Yale dealt with toxicity of carbon nanotubes to microorganisms as well as the effect of bacterial surface structures on bacterial adhesion and biofilm formation and maturation. She is currently an Assistant Professor at the University of Houston in the Department of Civil and Environmental Engineering. Her research interests involve investigation of the toxicological effects of carbon-based nanomaterials and polymer nanocomposites
Host: Astani CEE Department
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Cassie Cremeans
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Astani CEE Department Seminar
Wed, Mar 12, 2014 @ 10:00 AM - 11:00 AM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Ioannis A. Kougioumtzoglou , University of Liverpool
Talk Title: Wavelet Techniques & Path Integral Methods for Diverse Civil Engineering Applications
Abstract: Limitations pertaining to available information and the interpretation of underlying mechanisms, as well as inherent uncertainty and nonlinearity of critical engineering problems, have necessitated the study of nonlinear systems with stochastic parameters, input and initial/boundary conditions. In such cases, a stochastic approach constitutes a rational basis for modeling, analysis, design, monitoring and maintenance of resilient complex engineering systems. Further, stochastic dynamics has been the focus of diverse engineering and scientific disciplines for more than a century. Consequently, theoretical research has already led to seminal advancements towards analyzing and predicting the stochastic behavior of complex nonlinear dynamic phenomena. Nevertheless, the development of novel mathematical tools and of potent signal processing techniques, originating from computer science, applied mathematics and theoretical physics, offers a new framework for addressing complex problems for the first time and even posing new challenging questions.
In this regard, in the first part of the seminar talk, recent work related to the development of signal processing techniques for spectral analysis, stochastic modeling, and nonlinear system joint time/space-frequency response determination and parameter identification will be presented. A common denominator of the above techniques is the use of wavelets, and in particular, generalized harmonic wavelets which have proven to be particularly useful for engineering dynamics/mechanics related applications due to their non-overlapping, box-shaped frequency spectrum, their orthogonality properties, and the convenience of combining harmonic balance with statistical linearization techniques. Further, ongoing work related to the development of signal processing techniques which couple the localization capabilities of wavelets with compressive sensing methodology features for handling cases where available/measured data are highly sparse/incomplete will be delineated as well. Current and potential applications include translating (limited/incomplete/sparse and non-stationary) raw data into engineering load models and system/material properties, vibration diagnostics and mitigation, damage detection/assessment, cost-efficient structural health monitoring, and real-time risk optimization and decision making towards addressing the big challenge of analysis/design and operation of resilient and intelligent complex systems and civil infrastructure.
In the second part of the seminar talk, recent work related to the development of uncertainty quantification techniques for efficient response determination and reliability assessment of complex nonlinear systems will be presented. A common denominator of the above techniques is the use of path integrals. In this regard, it is noted that although path integrals have revolutionized the field of theoretical physics, the engineering community has neglected their potential as a potent uncertainty quantification tool. Current and potential applications include response analysis and reliability assessment of engineering systems following the versatile Preisach (hysteretic) model (e.g. smart materials), or modelled using fractional derivative elements (e.g. viscoelastic materials), as well as the determination of the capsizing probability of a ship model. Overall, it is shown that the path integral constitutes a versatile tool which can treat complex engineering problems and potentially address current and future challenges in engineering mechanics, such as nonlinearity and stochasticity at a multi-physics/scale level.
Biography: Dr. Ioannis Kougioumtzoglou (IK) is a Lecturer (Assistant Professor equivalent) in Uncertainty & Engineering, and a member of the Institute for Risk and Uncertainty and of the Centre for Engineering Sustainability in the School of Engineering, University of Liverpool, UK. He obtained his M.Sc. (2009) and Ph.D. (2011) degrees from the Civil and Environmental Engineering department of Rice University, TX, USA, under the supervision of Professor Pol D. Spanos. He also holds a five-year Diploma (2007) in Civil Engineering from the National Technical University of Athens (NTUA), Greece.
IK's primary research interests focus on the general area of Uncertainty Quantification and Modeling/Analysis of Complex Systems with applications mainly in Civil/Mechanical Engineering & Engineering Mechanics, and in diverse disciplines such as Financial Mathematics. Specifically, the development of numerical and/or analytical techniques for Stochastic Engineering Dynamics/Mechanics constitutes one of the main research themes. Systems exhibiting nonlinear/hysteretic behavior and/or exposed to hazard/risk inducing conditions are of particular interest.
IK has been awarded several scholarships for outstanding academic performance from the National State Scholarships Foundation (Greece), the Eugenides Foundation (Greece) and the Hellenic Professional Society of Texas (USA). He has also received an invited Visiting Professor appointment at the Structural Engineering Department, University of Sao Paulo, sponsored by the Sao Paulo State Research Funding Agency (Brazil). He is a member of the Engineering Mechanics Institute (EMI), an associate member of the American Society of Civil Engineers (ASCE), and a Registered (Licensed/Chartered) Professional Civil Engineer in Greece. He is the co-Editor of the Encyclopedia of Earthquake Engineering (Springer) and currently serves as a Guest Editor for two Special Issues in the Journal of Probabilistic Engineering Mechanics and in the International Journal of Reliability and Safety. He currently supervises and co-supervises nine PhD students, many of them in multi/cross-disciplinary topics.
Host: Astani CEE Department
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Cassie Cremeans
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Astani CEE Department
Thu, Mar 13, 2014 @ 10:00 AM - 11:00 AM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Kyle Doudrick, Arizona State University
Talk Title: Environmentally Responsible Use of Nanomaterials for the Photocatalytic Reduction of Nitrate in Water
Abstract: Nitrate is the most prevalent water pollutant limiting the use of groundwater as a potable water source. Current technologies available for treating nitrate in drinking water do not meet green principles and are ineffective as long-term solutions. Photocatalysis is emerging as a sustainable technology for treating contaminants that are difficult to remove using traditional treatment methods (e.g., nitrate). In this presentation, I will discuss research that leverages advances in nanotechnology to improve nitrate photocatalysis, the effect of charge transfer kinetics and pH, and the development of a framework for a nitrate-specific photocatalyst. I will also demonstrate the responsible use of nanomaterials by ensuring that appropriate detection methods are in place for the nanomaterials tested. While methods existed for the metals and metal oxides examined, there were none available for carbon nanotubes (CNTs). Acknowledging that risk assessment encompasses dose-response and exposure, new analytical methods were developed for extracting and quantifying CNTs in complex environmental (e.g., urban air) and biological matrices (e.g. rat lungs).
Biography: Kyle Doudrick is currently an NSF/ASEE Small Business Postdoctoral Research Diversity Fellow at Integrated Surface Technologies and an Adjunct Researcher at Arizona State University. He received B.S. and M.S. degrees from the University of Memphis in Civil Engineering and a Ph.D. from Arizona State University in Environmental Engineering. Dr. Doudrickââ¬â¢s research is focused on the development of sustainable water treatment technologies and the impact these technologies have on human health and the environment. Within this scope, his expertise lie in photoelectrochemical water treatment systems and quantification of nanomaterials in complex environmental and biological matrices.
Host: Astani CEE Department
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Cassie Cremeans
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Astani CEE Oral Dissertation Defense
Fri, Mar 14, 2014 @ 01:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Lesley Ewing, Astani CEE Ph.D. Student
Talk Title: Community Resilience to Coastal Disasters
Abstract:
Coastal communities are some of the major economic centers in both the US and the world, and coastal hazards make these areas prone to disasters. Resilience is joining the more traditional approaches available to communities for reducing the consequences of hazard events, which include erosion, inundation, flooding and wave impacts. Traditionally community resilience has covered both the extent to which a hazard event damages a community as well as the subsequent recovery; however, no method has been developed to assess community resilience resulting from various protection options.
The Coastal Community Hazard Protection Resilience Index (CCHPR Index) provides a measure of the resilience of a community’s existing coastal protection and opportunities to compare the changes community resilience brought on by different modifications or additions to coastal protection systems. This research describes the development of this index. It starts with an analysis of the key services of a community and the interdependencies of these services. The research then establishes four phases of a disaster â the pre-event phase, the event phase, the recovery phase, and the on-going activities phase. The key community services are characterized within these four disaster phases as are aspects of coastal hazard events. Lessons about coastal protection are discussed, based on field investigations of recent disasters. Coastal protection options are identified and evaluated for their effects on resilience throughout the four phases of a disaster, and these effects on resilience are used as inputs to the CCHPR Index.
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Astani CEE Ph.D. Seminar
Fri, Mar 14, 2014 @ 04:00 PM - 05:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Aycut Ayca and Nikos Kalligeris, Astani CEE Ph.D. Student
Talk Title: Current-Based Hazard Mapping in California Ports and Harbors
Abstract: First Presenter-Aycut Ayca
4:00-4:20pm(10 minutes Q&A)
As observed by recent tsunamis in California, maritime communities are the initial and primary communities to be impacted by tsunamis. These recent events which put portions of California’s coast into either an Tsunami Advisory or Warning levelâ¦2006 Kuril Islands, 2009 Samoa, 2010 Chile, 2011 Japan, and 2012 British Columbiaâ¦have caused over $100M in damages to over two dozen maritime communities in California.
In this presentation, the well-established approaches of coupling tsunami generation to seismic seafloor motion and the following trans-oceanic wave propagation will be briefly introduced. The focus of the discussion will be on the complex transformation of the tsunami as it approaches very shallow water, as well as how these possibly large and fast-moving water waves interact with coastal infrastructure. Most of the hydrodynamic results presented in this study come from the application of the âMethod of Splitting Tsunami’ (MOST) numerical model. The MOST model was developed in USC and has been used extensively for tsunami hazard assessments in the United States and is currently in operational use at NOAA’s Pacific Marine Environmental Laboratory (PMEL).
First part of this study will be current based hazard mapping. This will include predicting maximum current speeds in a particular port/harbor because of a tsunami and probabilistic assessment of tsunami-induced nearshore currents. The objective of this effort is to develop a set of probabilistic current maps (PCM’s) in a specific harbor. Output will be current maps at specific recurrence levels. The use of PCM’s would primarily be for planning and engineering design â mitigation of tsunami impacts. In addition, once the current-based hazard maps are developed, it becomes feasible to quantify risk and make informed decisions regarding existing and future development.
Then the modelling of debris and sediment movement and modeling updated mitigation measures within pilot study areas will be conducted. Then these would help with the development of 1) guidance for harbors to use with regard to debris and sediment movement, and 2) fragility curves for tsunami damage within harbors. This will be achieved by coupling MOST with a sediment transport model.
Second Presenter: Nikos Kalligeris
4:30-4:50 (10 minutes Q&A)
Location: John Stauffer Science Lecture Hall (SLH) - 102
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Astani CEE Ph.D. Seminar
Mon, Mar 17, 2014 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Mohammad Javad Abdolhosseini Qomi, Massachusetts Institute of Technology
Talk Title: A Multi-scale Approach to Sustainable infrastructure
Abstract: The fledgling state of civil infrastructure can be observed in many fronts including performance, longevity, durability, resilience, and sustainability. We produce 40% of global annual CO2 emissions in buildings, about half of which is related to space heating and cooling, and still about 1 billion people live in slums. Production of concrete, the most used man-made materials on earth with 1 cubic meter per capita per annum, is responsible for 5 to 8% of global carbon emissions; and yet it suffers from excessive aging and low durability.
Standing on the intersection of engineering and physics, I use tools from statistical physics and probabilistic mechanics to study problems ranging from the molecular structure of cement paste to retrofitability of cities. At the atomic level, I discuss the interplay between chemistry and physical properties by generating a realistic database of C-S-H (the glue of concrete) molecular structures. By screening the database against Maxwell and Lagrange constraint theory, I comment on the similarity between glass physics and cement science that provides a new venue for design of cementitious materials starting from nan-scale. At the city-scale, I explain a new Big Data approach designed to find the optimal path to reduce energy consumptions. To this end, I combine data analysis and heat transfer modeling to identify buildings with the highest energy saving potentials. Overall, I present a multi-scale mechanophysical approach toward sustainable infrastructure and discuss how this defines the outline of my future research directions. "
Biography: Mr. Abdolhosseini is a PhD-candidate in the department of Civil and Environmental Engineering at Massachusetts Institute of Technology. He did his undergraduate studies in Civil engineering at Tehran University and earned master degree in structural engineering from Sharif University of Technology. He is the recipient of MITââ¬â¢s Schoettler scholarship and Tavakkoli prize for distinguished research. His focus is on quantitative sustainability of complex materials and systems at nano- and mega-scale.
Host: Astani CEE Department
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Cassie Cremeans
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Astani CEE Department Seminar
Tue, Mar 25, 2014 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Chiara Villani , Purdue University
Talk Title: Transport Processes in Partially Saturated Concrete: Testing and Influence of Liquid Properties
Abstract: The interest of the scientific community in transport properties of cementitious materials is motivated by their relevance in the service life prediction, an attractive instrument to move towards more sustainable construction practices. This aspect has encouraged the development of several transport tests. However, designing a transport test that is sensitive, robust, easy to perform, that provides a material property seems to be a real challenge in the case of concrete. Permeability tests have been proved to be highly sensitive to several parameters. In this context, this study aimed at investigating existing gas transport tests comparing their performance in terms of repeatability and variability. The influence of several parameters was investigated such as moisture content, mixture proportions and gas flow. A closer look to the influence of pressure revealed an anomalous trend of permeability with respect to pressure. An alternative calculation is proposed in an effort to move towards the determination of intrinsic material properties.
The impact of deicing salts exposure was also analyzed with respect to gas transport of cementitious materials focusing on their alteration of the drying processes. Limited information were previously available on liquid properties such as surface tension, viscosity, water activity in presence of deicing salts over a wide range of concentrations. To overcome this limitation, this study quantified those properties in a broad concentration range and at different temperatures. Existing models were applied to predict the change of fluid properties during drying. Desorption tests were performed to investigate the influence of deicing salts presence on the non-linear moisture diffusion coefficient. In an effort to predict moisture profiles semi-empirical models were applied to quantify the initiation and the rate of drying using liquid properties and pore structure information as inputs. Concrete exposed to deicing salts resulted to have a reduced gas transport due to the higher degree of saturation (DOS). This is believed to contribute to the premature deterioration observed in concrete pavements exposed to deicing salts.
Biography: Chiara Villani is a Ph.D. candidate at Purdue University. She received her B.S. and M.S. in Civil Engineering from the Polytechnic of Turin. Prior to Purdue University, she worked as a researcher in the CEMEX Research Group AG characterizing low carbon footprint fiber-reinforced self-compacting composites. While at Purdue, she investigated limitations and potentials of existing and new transport tests for permeability evaluations. She analyzed the deterioration mechanisms associated with deicing salts presence focusing on their influence on the drying process of cementitious materials. She has also contributed to the mechanical and microstructural characterization of sustainable composites containing supplementary cementitious materials and of composites cured with carbon dioxide. Her research interests include development and characterization of sustainable cementitious materials, drying processes in cementitious composites and durability of concrete structures.
Host: Astani CEE Department
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Cassie Cremeans
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Astani CEE Department Seminar
Thu, Mar 27, 2014 @ 10:00 AM - 11:00 AM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Charles-Francois de Lannoy , Duke University
Talk Title: The Environmental Applications and Implications New Composite Materials
Abstract: Increasing our potable water supply, improving the efficiency and effectiveness of water/wastewater treatment, and decontaminating natural water systems are all cyclically dependent. Addressing future water concerns requires that we investigate all components of this water-health nexus simultaneously. As water sources are further strained, long-term solutions to efficient and effective ways of dealing with our water problems will become increasingly vital to our society. Among the many current approaches is the development and novel use of new materials. Nanocomposite materials, in particular, are leading the way towards highly effective solutions to these challenging environmental problems.
I have developed a suite of novel nanomaterials with direct environmental applications. These materials take the form of electrically conductive membrane coatings, active separation surfaces, catalytic nanomaterials for environmental decontaminations, and reactive adsorbents. In all forms, we are cognizant of the environmental implications of nanomaterials, and strive towards sustainable material development and responsible environmental use.
In this talk I will focus on two approaches: 1) new strategies for water/wastewater treatment and 2) degradation of aquatic environmental contaminants. In the former case I will introduce the development and application of our novel electrically conductive active membrane surfaces. Membrane technologies, while efficient and effective methods to treat water and wastewater, are plagued by several problems, in particular biofouling. Our active membrane surfaces demonstrate superior biofouling resistance in challenging environments and over long-term studies. The second topic of my talk will explore new nanocomposite reductive adsorbents for environmental decontamination. These nanocomposites have high reductive potential for rapid and effective degradation of emerging environmental contaminants, high transport properties for large site area coverage, and environmentally inert byproducts for safe in-situ application.
The nanocomposite materials that I have developed and the various platforms we have tested have the potential to pave the way for indiscriminately broad-scoped solutions to dynamically evolving global environmental problems.
Biography: Dr. Charles-François de Lannoy received his Ph.D. in Civil and Environmental Engineering and Certificate in Nanoscience from Duke University in 2014 under Prof. Mark Wiesner, and his B.Sc. in Honours Physics with High Distinction from McGill University. He is currently a post-doctoral research associate at CEINT (Center for the Environmental Implications of Nanotechnology) an NSF-EPA supported center at Duke University. His research is focused on the investigation of nanocomposite materials and their application and implication to environmental systems. In his Ph.D., Charles developed, characterized, and tested polymer-carbon nanotube composite membranes for diverse applications in water purification and desalination technologies. He is among the pioneers in a new field in electrically conductive polymer membrane surfaces, which have wide applications to biofouling resistant surfaces, catalytic surfaces for contaminant degradation, and active separation surfaces for charged particle separation. He has published several papers in ES&T, Langmuir, and the Journal of Membrane Science, his work has been awarded several awards at national and international conferences, and he has two provisional patent filings at Duke University for two of the materials that he has developed.
Host: Astani CEE Department
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Cassie Cremeans
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Astani CEE Ph.D. Seminar
Fri, Mar 28, 2014 @ 04:00 PM - 05:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Esther S. Lee, USC Career Center
Talk Title: USC Career
Location: John Stauffer Science Lecture Hall (SLH) - 102
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Astani CEE Department Seminar
Mon, Mar 31, 2014 @ 10:00 AM - 11:00 AM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Jun Li , California Institute of Technology
Talk Title: Time and Temperature Dependent Large Deformation of Membranes for Sustainable Technology Applications
Abstract: Membranes are becoming increasingly important and widely used in sustainable technology including deployable and lightweight structures, environmental protection and purification systems, and energy conversion and storage devices. Understanding the mechanics of membranes that exhibit time and temperature dependent large deformation behavior is critical to ensure long-term viability in applications. However, the nonlinear viscoelasticity of polymers coupled with the thinness of membranes pose challenges in characterization and modeling. In this talk, I will describe a hybrid method (experimental + computational) to develop nonlinear orthotropic viscoelastic models for the linear low density polyethylene (LLDPE) membranes used in the NASA Ultra Long Duration Balloon. I will first discuss their linear viscoelastic characterization through creep tests and harmonic oscillation tests to obtain master curves of creep compliance. I will show that the master curves obtained from these approaches are not equivalent due to the semi-crystalline nature of LLDPE and one has to be careful to choose between the two approaches. A large deformation model based on the free volume theory couples the through-plane strain to the in-plane deformation of the membrane, but in practice the through-plane properties are difficult to measure. I will present a two-step computational scheme combining an evolutionary algorithm and a simplex optimization to extract model parameters through inverse analysis of experimental results. The validity of the model is then demonstrated on tests at different temperatures and strain rates. Finally, I will discuss possible avenues of future development. Effective constitutive models permit the integration with finite element models to study more complicated mechanics problems involving stress concentrations, wrinkling, structural instabilities and failure. The inclusion of other internal parameters will extend the applicability to multiphysics problems of coupled thermo-photo-chemo-electro-magneto mechanics in diverse applications.
Biography: Dr. Jun Li is a postdoctoral scholar in the Graduate Aerospace Laboratories at the California Institute of Technology. He received his Ph.D. in Mechanical Engineering from the University of Illinois at Urbana-Champaign (UIUC) in 2012, as well as M.S. in Mathematics and in Theoretical and Applied Mechanics. At UIUC, he contributed to the mechanics of fractal and random materials resulting in over 10 journal publications. He delivered a keynote at the 10th US National Congress on Computational Mechanics and received the best poster award of ââ¬ÅEmerging Researchers in Biomedical Engineeringââ¬Â at 2011 ASME International Mechanical Engineering Congress and Exposition. Prior to UIUC, he obtained B.S. in Mechanical Engineering with a minor in Mathematics from Shanghai Jiaotong University in 2005. His research interest is to develop theoretical analysis tools integrated with computational techniques and experimental characterizations for the design, optimization, and assessment of novel materials and structures.
Host: Astani CEE Department
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Cassie Cremeans