Conferences, Lectures, & Seminars
Events for March
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Astani CEE Department Seminar
Mon, Mar 05, 2012 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Kristina M. Wagstrom, Postdoctoral Associate, , Department of Civil Engineering, University of Minnesota
Talk Title: Relating Emissions and Particulate Matter Concentrations in the Complex Ambient Atmosphere
Abstract:
In order for policy makers to effectively regulate emissions, there needs to be a strong understanding of the relationships between emissions and resulting air pollutant concentrations even in the complex mixtures that make up many airsheds. In order to more fully relate sources and ambient pollutant concentrations, I have implemented and evaluated an algorithm capable of tracking the contributions of different sources types and locations to particulate matter concentrations in a three-dimensional atmospheric chemical transport model. I will discuss the details of this algorithm and its utilization to study the origins of particulate matter in the Eastern United States. I used three different approaches in order to create a more complete picture of pollutant origins:
1) I quantified the impacts of emissions from large source regions on the particulate matter concentrations in surrounding areas as pollutants are transported out of those areas into surrounding regions.
2) I studied the contributions from transported pollutants on local air quality problems by identifying the distance pollutants are transported before arriving in regions of interest.
3) I estimated the average age of particulate matter in the atmosphere by tracking when pollutants were emitted. Knowing the age of particulate matter gives us insight into the relative importance of many processes in the atmosphere.
This work has increased our understanding of the impacts of emissions and pollutant transport on particulate matter concentrations. Our studies have suggested that a large fraction of the ground level concentrations of primary (directly emitted) particulate matter in urban areas tend to be from local emissions while the concentrations of secondary species (formed in the atmosphere) such as sulfate or secondary organic particulate matter are more likely to result from regional sources. I found that the distance, direction and amount of particulate matter transport occurring from large source regions was highly variable in time and dependant on particulate matter species. The ages found for particulate matter species were highly variable in time, space (both horizontally and vertically) and by species. Primary species were found to have ages on the order of one to two days while secondary species had ages ranging from one to several days. These results provide information about the relative importance of different reactions and pollutant transport processes in the atmosphere which provides insight for future model development and guidance for policymakers.
Location: Kaprielian Hall (KAP) - 209 Conference Room
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Astani Civil and Environmental Engineering Seminar
Wed, Mar 07, 2012 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: George Ban-Weiss, Postdoctoral Research Associate , Lawrence Berkeley National Lab
Talk Title: Aerosols: From the Tailpipe to Climate Change
Abstract:
Aerosols are fine suspensions of liquid droplets and solid particles that exist in a vast variety of shapes, sizes, and compositions in Earthâs atmosphere. Aerosols can cause adverse health effects, degrade visibility, soil buildings and materials, damage crops, and alter Earthâs energy balance leading to climate change.
Aerosols are known to be an important cause of climate change, but the magnitude of the change is highly uncertain. The effect of aerosols on climate depends on many factors; some particle species cause global warming and some cause cooling. Black carbon aerosols absorb solar radiation and are widely thought to be the second most important cause of global warming after CO2. I will use results from global climate model simulations to show that the climate effect of black carbon is highly dependent on its altitude in the atmosphere. Black carbon at some altitudes can even cause global cooling despite the fact that they increase atmospheric absorption of sunlight.
Motor vehicle emissions are an important source of aerosols. Quantifying vehicle emissions using traditional laboratory methods can be challenging due to the need to extrapolate from a small sample of vehicles to the entire in-use population. This seminar will discuss measured aerosol emissions from a large sample of individual on-road heavy-duty diesel trucks. The statistical distribution of aerosol emissions from diesel trucks (i.e. the relative importance of high-emitters as a source of vehicle-related pollution), and the potential climate implications of diesel particle filter retrofit programs will be explored.
Location: Kaprielian Hall (KAP) - 209 Conference Room
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Astani Civil and Environmental Engineering Seminar
Thu, Mar 08, 2012 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Lu-Maan Chang, Professor Emeritus, Purdue University , Professor and Director, High-Tech Facility Research Center, Department of Civil Engineering, National Taiwan University
Talk Title: HIGH-TECH FACILITY ENGINEERING IN NT ERA
Abstract:
Key Words: Cleanroom, Construction, Green Building, High-Tech, Microelectronics, Nanotechnology, Semiconductor, Vibration
Nanotechnology (NT) will not only improve the technology for understanding the foundation of matter at the atomic, molecular, and supermolecular levels but will have as profound an impact on our economy, quality of life, and education as the information technology (IT) has had in the last two decades.
To cope with the new challenges ahead, many academic institutes and industrial companies around the world have invested heavily in pursuing Nano-R&D and Nano-Manufacturing (Nano-R&D&M) in recent years. Predictably, the demand for high-tech facilities and the corresponding skillful engineers will be strong and inevitable. Presently, there is no university in Asia offering high-tech facility engineering program specifically for Nano-R&D&M. To facilitate the advancement of Nano-R&D&M, and to meet the potential demand of the engineers, the Civil Engineering Department of National Taiwan University initiated a High-Tech Facility Research Center in fall 2006 and is offering a High-Tech Facility Design course in spring 2007.
This paper will begin with the introduction of NT and its impact on facility design and construction following by the discussion of the sensitivity in micro-vibration of high performance nano-scopes. Since most of the Nano-R&D&M processes must be done in a stringently controlled cleanroom, without a proper cleanroom, the Nano-R&D&M can neither be performed well nor advanced further. Therefore, the paper will then focus on the fundamentals in cleanroom design. Finally, the NTU High-Tech Research Center and the High-Tech Facility Design course will be briefly presented.
This paper was published in CECI engineering technology, CECI, Taipei, Taiwan, April 2007, Vol.74, pp.22-37
Location: Kaprielian Hall (KAP) - 209 Conference Room
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Astani Civil and Environmental Engineering Seminar
Wed, Mar 21, 2012 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Scott C. James, Principal Member of the Technical Staff, Sandia National Laboratories
Talk Title: Reactive Flow and Transport in Environmental Systems: Energy Considerations
Abstract: This presentation is a compilation of some of my research interests that span the fields of groundwater hydrology, surface-water hydrology, and renewable energy (e.g., algal biofuels and marine hydrokinetic energy). More specifically, my research developments in the areas of (a) colloid transport in fractured formations, (b) computational fluid dynamics simulations for marine hydrokinetic energy, and (c) optimizing algae growth in open-channel raceways for biofuel production will be presented.
Analytical, theoretical, and computational investigations examining fate and transport of colloid and contaminant plumes in fractured porous media were conducted. Initially, analytical solutions to the mathematical model describing the transport of finitely sized colloids in a uniform-aperture fracture subject to several different boundary conditions were developed. A novel particle tracking algorithm was verified through comparisons to newly developed analytical solutions. This particle-tracking algorithm was used to examine general transport characteristics of polydisperse colloid plumes in a uniform aperture fracture, focusing on the effects of their finite size. Finally, because natural fractures are rough, the particle tracking algorithm was extended to examine colloid and contaminant co-transport within a quasi-three-dimensional spatially-variable-aperture fracture.
Marine hydrokinetic (MHK) energy research was conducted to gain a better understanding of how to convert energy (momentum) from a system with minimum impact on the marine environment. The EPAâs Environmental Fluid Dynamics (EFDC) code was modified to represent
MHK devices as momentum sinks with commensurate adjustments to the turbulent k- terms. Turbulence equation coefficients were calibrated to ensure that simulated wakes from a turbine in a laboratory flume matched the experimental data. Also, the sediment dynamics algorithms were updated to include a unified treatment of cohesive and noncohesive sediments as well as effects of bedslope and consolidation. Removing energy from a system can result in changes to circulation including decreased water-level ranges and increased residence times. The model helps determine an appropriate amount of energy that can be generated from an MHK site â an amount that prevents environmental degradation while also suggesting device locations that optimize energy capture.
Significant research on algae growth in open-channel raceways was conducted to better understand the important parameters affecting biomass production with the goal of achieving cost-competitive biofuels. Water-quality algorithms in EFDC were modified and improved to be applicable to high-density algal systems and to account for the effects of growth limitation as a function of CO2 concentrations and pH fluctuations. The model faithfully reproduced a few simple algae growth test problems and was easily extended to accurately simulate the data collected from an algae growth experiment conducted in a greenhouse. Working in conjunction with industry partners, the model is currently employed for the simulation of algae growth in various conceptual models of open-channel raceways.
Fluid dynamics research is integral to developing alternative energy platforms. Water and energy are inextricably coupled; it is virtually impossible to consider one independently from the other. Given the emphasis on energy and the environment, an environmental engineer must employ broad civil and mechanical engineering skills to tackle this multidisciplinary field.
Host: Sonny Astani Department of Civil and Environmental Engineering
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Cassie Cremeans