News & EventsDepartment Events
Events
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Oct23
EVENT DETAILS
lessAbstract: Steel plate girder bridges with concrete slab decks are prevalent in the U.S. highway system, with many nearing or exceeding 45 years of service. Currently, around 26% of these bridges are structurally deficient due to concrete slab delamination, excessive cracking, and steel girder corrosion, which leads to costly rehabilitations and reduced load ratings. This study focuses on predicting the effects of corrosion on steel girders and proposing a novel solution to extend bridge service life without full replacement or load rating reduction. Experimental investigations assessed corrosion morphology and its impact on mechanical performance under varying chloride concentrations, temperature conditions, and the presence of mill scale. Results showed that mill scale can initiate corrosion even in chloride-free environments and that corrosion morphology significantly affects ductility, rendering simplified design approaches based on average area loss inaccurate. To mitigate load reductions caused by corrosion, the study proposes replacing conventional reinforced concrete slabs with lighter Ultra-High Performance Concrete (UHPC) slabs, reducing dead load by over 20%. A case study on a 43-year-old bridge in Pennsylvania demonstrated that this method allows the bridge to maintain full live load capacity without rehabilitating the steel girders. Additionally, a new method for casting UHPC slabs with preferential fiber orientation was developed to enhance structural strength. Finally, the interaction between steel fiber volume fraction and reinforcing rebars was studied in UHPC beams with prismatic cross-sections.
Bio: Shady Gomaa holds a Ph.D. in Civil Engineering (2020) from Rensselaer Polytechnic Institute, along with an M.S. in Structural Engineering and a B.Sc. in Civil Engineering from Zagazig University in Egypt. He is currently a postdoctoral scholar in the Department of Civil and Environmental Engineering at Northwestern University. His research focuses on additive manufacturing of Ultra-High Performance Concrete (UHPC), with broader interests in steel corrosion, sustainability, concrete mechanics, and deterioration mechanisms in materials and structures. Shady is an active member of ACI Committees, including Committee 564 on 3D Printing with Cementitious Materials and Committee 239 on Ultra-HighPerformance Concrete.
TIME Wednesday, October 23, 2024 at 11:00 AM - 12:00 PM
LOCATION A230, Technological Institute map it
CONTACT Andrew Liguori andrew.liguori@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering (CEE)
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Oct24
EVENT DETAILS
lessAbstract: Energetic materials are solids that can release significant energy upon stimuli. They can constitute propellants, explosives, fuels, and pyrotechnics used in aerospace, mining, and defense industries. To reduce the sensitivity of the materials and enhance safety, energy materials are often manufactured as two-phase composites, with a softer binder as the host matrix that holds the explosive crystals, such as HMX (High-melting Explosive) in place. This design, referred to as Polymer-bonded explosives (PBX), enables the molding, shaping, and uniformity of the materials, leading to improved predictable performance. Nevertheless, the characterization of the energy localization often requires a material model capable of handling extremely large deformation of phase transformation. This talk reports recent progress on forward and inverse problems for modeling the HMX and PBX enabled by machine learning. For the forward modeling problems, we attempt to create mathematical models of HMX expressed in symbolic form. To avoid the difficulty of training the Kolmogorov-Arnold network, we introduce an alternative technique to learn neural additive basis in projected feature space to control the expressivity-speed trade-off. For the inverse problem, we introduce a generative AI that enables us to create highly realistic PBX microstructures as well as the granular microstructures of crystals by separately handling the generation of grain geometry and topology of the granular structures via conditional latent diffusion and graph recurrent neural network. Benchmark numerical examples of material point simulations for shock loading in b-HMX are performed to assess the practicality of using the discovered machine learning models for high-fidelity simulations.
Bio: Dr. Sun has been an associate professor at Columbia University since 2020. He obtained his BS from UC Davis (2005), MS in civil engineering (geomechanics) from Stanford (2007), MA (Civil Engineering) from Princeton (2008), and Ph.D. in theoretical and applied mechanics from Northwestern (2011). Sun’s research focuses on theoretical, computational, and data-driven mechanics for porous and energetic materials. He is the recipient of a few awards, including the Walter Huber Civil Engineering Research Prize (2023), the IACM John Argyris Award (2020), the EMI Leonardo da Vinci Award (2018), the Zienkiewicz Numerical Methods Engineering Prize (2017), and early career awards from NSF, AFOSR, and ARO.
TIME Thursday, October 24, 2024 at 11:00 AM - 12:00 PM
LOCATION A230, Technological Institute map it
CONTACT Andrew Liguori andrew.liguori@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering (CEE)
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Oct25
EVENT DETAILS
lessAbstract: Engineered nanomaterials (ENMs) can alter surface properties of cells and disturb cellular functions and gene expression through direct and indirect contact, exerting unintended impacts on human and ecological health. However, the effects of interactions among environmental factors, such as light, surrounding media, and ENM mixtures, on the mechanisms of ENM toxicity, especially at sublethal concentrations, are much less explored and understood. Recent studies have shown that nanoparticles can facilitate bacteriophage infection which contributes to transduction, an understudied yet crucial pathway of antibacterial gene transfer in bacteria. Therefore, we first evaluated cell viability and outer membrane permeability of E. coli as a function of exposure to environmentally relevant concentrations of ENMs, including metal (n-Ag) and metal oxide (n-TiO2, n-Al2O3, n-ZnO, n-CuO, and n-SiO2) nanoparticles under dark and simulated sunlight illumination in MOPS, a synthetic buffer, and Lake Michigan Water (LMW), a freshwater medium. Then we investigated the effects of photoactive ENMs on bacteriophage infection under sublethal concentrations and tried to unravel the mechanisms in gene expression associated with F-pili and membrane proteins. Our results reveal the significant sublethal bacterial stress exerted by ENMs and ENM mixtures at the cell surface in natural environments at low doses, which potentially affects cell susceptibility to toxicants and virus, such as phage infection and eventually causes unpredictable impacts on overall ecological health.
Bio: Shushan Wu is a 6th year PhD student in Professor Kimberly Gray’s group. Her work unveils the sublethal bacterial stress exerted by engineered nanomaterials under environmental conditions using advanced biological techniques. Shushan graduated from Auburn University with a bachelor's degree in civil and environmental engineering before pursuing graduate studies at Northwestern University.
TIME Friday, October 25, 2024 at 2:00 PM - 3:00 PM
LOCATION A230, Technological Institute map it
CONTACT Andrew Liguori andrew.liguori@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering (CEE)
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Nov1
EVENT DETAILS
lessAbstract: Achieving carbon circularity and net zero emissions requires a comprehensive understanding of emissions and re-valorization of waste carbon, while keeping fossil carbon underground. Environmental engineers are uniquely positioned to lead sustainable carbon management as the “circular carbon engineers”. For example, modern wastewater treatment is evolving from “removal-centered” to a “recovery-oriented” approach, and the increasing availability of low-cost renewable electricity presents new opportunities to convert "electrons to molecules". This presentation will highlight recent efforts to address knowledge gaps in the complex GHG emission profiles of the wastewater sector, utilizing both field studies and data science methods. It will also discuss technologies for electrifying treatment processes, co-valorizing wastewater and CO2, performing electrolysis of impaired water, and producing commodity chemicals using electroactive membranes.
Bio: Dr. Zhiyong Jason Ren (https://ren.princeton.edu) is a professor in the department of Civil and Environmental Engineering and the Andlinger Center for Energy and the Environment at Princeton University. He leads the Princeton Water & Energy Technologies (WET) Lab with research focusing on water sector decarbonization and digitalization. His group uses electrochemistry, microbiology, and data science tools to gain insights into the fundamental determining factors, and they develop models and technologies for resource recovery during environmental and chemical processes. Dr. Ren has received numerous recognitions including the Walter J. Weber, Jr. AEESP Frontier in Research Award (2024), the Paul L. Busch Award (2021), and Walter L. Huber Research Prize (2020). He is a Fellow of Royal Society of Chemistry and International Water Association. He is an Associate Editor for Environmental Science & Technology (ES&T) and ES&T Letters. Ren received his Ph.D. in environmental engineering from Penn State University.
TIME Friday, November 1, 2024 at 2:00 PM - 3:00 PM
LOCATION A230, Technological Institute map it
CONTACT Andrew Liguori andrew.liguori@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering (CEE)
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Nov8
EVENT DETAILS
lessTBA
TIME Friday, November 8, 2024 at 2:00 PM - 3:00 PM
LOCATION A230, Technological Institute map it
CONTACT Andrew Liguori andrew.liguori@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering (CEE)
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Nov13
EVENT DETAILS
lessTBA
TIME Wednesday, November 13, 2024 at 11:00 AM - 12:00 PM
LOCATION A230, Technological Institute map it
CONTACT Andrew Liguori andrew.liguori@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering (CEE)
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Nov15
EVENT DETAILS
lessTBA
TIME Friday, November 15, 2024 at 2:00 PM - 3:00 PM
LOCATION A230, Technological Institute map it
CONTACT Andrew Liguori andrew.liguori@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering (CEE)
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Dec4
EVENT DETAILS
lessTBA
TIME Wednesday, December 4, 2024 at 11:00 AM - 12:00 PM
LOCATION 230, Technological Institute map it
CONTACT Andrew Liguori andrew.liguori@northwestern.edu EMAIL
CALENDAR McCormick - Civil and Environmental Engineering (CEE)
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Dec7
EVENT DETAILS
lessFall classes end
TIME Saturday, December 7, 2024
CONTACT Office of the Registrar nu-registrar@northwestern.edu EMAIL
CALENDAR University Academic Calendar
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Dec14
EVENT DETAILS
lessThe ceremony will take place on Saturday, December 14 in Pick-Staiger Concert Hall, 50 Arts Circle Drive.
*No tickets required
TIME Saturday, December 14, 2024 at 4:00 PM - 6:00 PM
LOCATION Pick-Staiger Concert Hall map it
CONTACT Andi Joppie andi.joppie@northwestern.edu EMAIL
CALENDAR McCormick School of Engineering and Applied Science