Conferences, Lectures, & Seminars
Events for February
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Astani CEE Ph.D. Seminar
Fri, Feb 07, 2014 @ 04:00 PM - 05:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Professor Emile A. Okal , Northwestern University, Ullinois
Talk Title: The implosive component of the 2013 Okhotsk Sea deep earthquake: Evidence from radial modes and constraints from geodetic data
Abstract: Ever since Bridgman's (1945) original suggestion, the presence of an implosive component in the source of deep earthquakes has long been a passionately debated subject, which is re-openened by the occurrence of the 2013 Sea of Okhotsk earthquake, the largest ever recorded deep event.
The analysis of the fundamental and first overtone radial modes, 0s0 and 1s0, allows the resolution of such a component without trade-off with the relevant deviatoric component. We document the presence of an implosive component valued at 2 percent of the scalar moment tensor (but 9 percent of the deviatoric component exciting radial modes). The implosive component is also resolved
by CMT inversion when the zero-trace constraint is relaxed, but with a significantly larger amplitude (8 percent of the scalar moment).
The near field of three-dimensional static deformation by the earthquake is reconstructed from data at permanent GPS stations in the epicentral area, with maximum observed deformations on the order of 1 cm (horizontal) to 2 cm (vertical). Preliminary modeling indicates that the influence of the proposed imnplosive components (especially as derived from CMT inversion) may be resolvable from this dataset at critically located GPS stations, of which a full investigation will be presented.
We further show that a small tsunami from this very deep earthquake was detected at two regional DART buoys, and that its amplitude (3 to 4 mm peak-to-peak) is well accounted for by a number of crude, back of the envelope calculations.
Host: Prof. Costas Synolakis
Location: John Stauffer Science Lecture Hall (SLH) - 102
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Astani CEE Seminar
Thu, Feb 13, 2014 @ 10:00 AM - 11:00 AM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Xing Xie, Stanford University
Talk Title: Advanced Materials and Nanotechnology for Environmental Applications
Abstract: Advanced materials and nanotechnology are powerful tools that have been changing our lives dramatically. However, we are still facing very challenging environmental issues, such as water contamination, air pollution, and climate change. To tackle these environmental issues, my research focuses on applying advanced materials and nanotechnology to enhance the performance of existing environmental technologies, and to develop new technologies that can provide better solution to various environmental issues. In this presentation, I will introduce two different environmental applications. One is about nano-enhanced microbial electrochemical cells for wastewater treatment and energy recovery. I have developed 3D bio-electrodes for microbial electrochemical cells with superior performance. I also have invented a new microbial electrochemical device, named “microbial battery”, achieving higher than 30% energy efficiency. The other application is about nano-assisted new technologies for efficient water disinfection. In one example, strong electric field generated near the tips of nanowire structures is applied to kill bacteria and viruses in water. Removal efficiencies higher than 6-log have been achieved with retention times less than one second. In another example, water disinfection is realized by employing silver nanoscavengers, which are nanodisks with magnetic cores and silver capping layers. The silver nanoscavengers can be separated from treated water effectively after treatment and reused for thousands of times.
Biography: Xing Xie received his B.S. (2006) and M.S. (2008) degrees from Tsinghua University, and he is currently a Ph.D. candidate in the Department of Civil and Environmental Engineering at Stanford University and a Henry Fan Fellow supported by the Stanford Interdisciplinary Graduate Fellowship. His research mainly focuses on applying advanced materials and nanotechnology for environmental applications. He has worked on many projects related to microbial electrochemical cells, water disinfection, water reuse, algae control, mixing entropy batteries, electrochemical capacitors, and Li-ion batteries. He has published more than 20 peer-reviewed articles in leading journals, including PNAS, Nature Communications, Nano Letters, Energy & Environmental Science, and ACS Nano. He received the Larry C. K. Yung Fellowship in 2008-2009, the David and Lucile Packard Foundation Fellowship in 2009-2011, and the Graduate Student Award in Environmental Chemistry from the American Chemical Society in 2012.
Host: Astani CEE Department
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Cassie Cremeans
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CEE Ph.D. Seminar
Fri, Feb 21, 2014 @ 04:00 AM - 05:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Arian Safari and Arsalan Heydarian, Astani ENE Ph.D. Students
Talk Title: Toxico-chemical properties of size-fractionated airborne particulate matter and implications for human health / Measuring the Impact of Personal Control and Energy Use through the Use of Immersive Virtual Environments.
Abstract: Presenter: Arian Safari
Exposure to atmospheric particulate matter (PM) has been linked to several adverse health effects, including but not limited to respiratory and cardiovascular diseases in addition to neurological disorders. There is growing literature supporting the hypothesis that one of the important pathways underlying these adverse health endpoints is the oxidative stress (e.g. ROS generation) that derives from the interaction of PM with cells. Elevated ROS levels can alter the redox status of the cell and consequently trigger a series of acute and chronic responses such as pulmonary inflammation and mitochondrial damage. This talk would focus on the PM-induced oxidative stress, its temporal and spatial variations, its relationship with chemical composition and PM emission sources and implications for toxicity assessment and human health. Moreover, a summary of the results of our recent studies in the Los Angeles south coast air basin will be discussed.
Presenter: Arsalan Heydarian
Title: Measuring the Impact of Personal Control and Energy Use through the Use of Immersive Virtual Environments.
Absract:
Recent studies have focused on increasing energy efficiency in commercial buildings through technological means (e.g., efficient HVAC systems, sensors and sensing systems). However, most studies underestimate the impact of occupants’ behavioral choices. This presentation focuses on measuring the impact of personal control and energy consumption behaviour through the use of immersive virtual environments. The presentation will focus on two main topics the (1) evaluation of human interaction within immersive virtual environments compared to the physical environments and (2) the impact of personal control on lighting use in office environments. The presentation is broken down into the following components: discussion of the problem statement, use of immersive virtual environments to study alternative designs, brief discussion of the pilot experiments, and future works.
Location: SLH 102
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Astani CEE Ph.D. Seminar
Fri, Feb 28, 2014 @ 04:00 PM - 05:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Wen-Young Liu and Yujing Hu , Astani CEE Ph.D. Students
Talk Title: Diffraction of Elastic Waves Around Layered Strata With Irregular Topography / Seismic Performance of Tilt-Up Structures
Abstract: First Presenter: Wen-Young Liu
Diffraction Around an Irregular Layered Elastic Media â Love and Body SH Waves, Rayleigh and Body P-SV Waves are to be investigated by weighted-residual method along with Fourier half-range wave expressions. Diffracted mode shapes and spectral amplification characteristics of Love and Body SH Waves, Rayleigh waves and P-SV-waves at different frequencies are examined and discussed.
Second Presenter: Yujing Hu
Title: Performance of Tilt-Up Structures
Abstract:
Tilt-up construction is a cost-effective technique which has been widely used in North America, South America and New Zealand. It is estimated that over 15% of all industrial buildings are Tilt-Up in the United States. Although economical to build, this type of structure is vulnerable to strong ground motions. Severe damage to tilt-up structures is reported during past major earthquakes around the world. This research evaluates the effects of moderate and strong ground motions on different types of tilt-up buildings, in order to estimate the potential vulnerability of the structural system. Three dimensional, linear and nonlinear models of three types of tilt-up structures are developed. Nonlinear elements are incorporated for Gluam Beam/Wall connections, Purlin/Wall connections, Panel/Panel connections and roof. Inelastic characteristics for these components are obtained from a series of previous experiments. In addition, cumulative damage of some critical structural components of tilt-up structures is studied by considering low-cycle fatigue problem.
Location: SLH 102
Audiences: Everyone Is Invited
Contact: Evangeline Reyes