Warren Distinguished Lecture Series Home

The Warren Distinguished Lecture Series is made possible by a generous, renewing gift by Alice Warren Gaarden in 1961. Since 1989, we have been bringing in accomplished researchers and speakers from around the world to share their work with students, faculty, and friends of CEGE. Please join us for these lectures!

Upcoming Warren Lectures

Overview of the Fall 2022 Season
September 16  Xue Feng, Civil, Environmental, and Geo- Engineering, University of Minnesota
September 23  Three Minute Thesis Contest, Graduate Students, University of Minnesota
September 30  DEXTER LECTURE Constantin Christopoulos, Civil and Mineral Engineering, University of Toronto 
October 7         Carsten Prasse, Environmental Health and Engineering, Johns Hopkins
October 14       Laurel Larsen, Geography, University of California Berkely (online only)
October 21       Pierre Gentine, Earth and Environmental Engineering, Columbia University (online only)
October 28       Roberto Leon, Civil and Environmental, Virginia Tech
November 4     Career panel
November 11   Scott Moura, University of California Berekley 
November 18   Peter Kelemen, Earth and Environmental Sciences, Columbia University
December 2     Wei Chen, Northwestern University (online only)
December 9     Sarah Billington, Civil and Environmental Engineering, Stanford
December 16   Mary Armstrong, Environmental Science and Environmental Studies, Lafayette (online only)

Chemical Exposures: Novel Approaches for the Identification of Toxic Organic Chemicals in Complex Mixtures 

Carsten Prasse
Environmental Health and Engineering
Johns Hopkins University

ABSTRACT:  Exposures to anthropogenic chemicals are a key contributor to the human “exposome”, or the sum of environmental stressors that shape and determine health outcomes. In addition to more 85,000 chemicals in commercial use today, we are exposed to thousands of chemicals formed when anthropogenic and natural organic compounds degrade in the environment and/or engineered systems. Frequently it is exposure to a complex mixture of chemicals that results in additive, adverse health effects. However, engineered systems for human and environmental health protection–like drinking water and wastewater treatment–rely on chemical-by-chemical assessments and regulations that rarely consider complex mixtures. Moreover, approaches that help prioritize identification and treatment of the most toxic chemicals are widely missing. As a result, adverse environmental and human health outcomes, unintended consequences of engineered treatment solutions, and inadequate regulations only become evident years after populations have been exposed. If we want to address this issue, we need to develop approaches that help us identify those chemicals that are of highest concern for human health and the environment. In this seminar, I will discuss the development and application of a novel analytical approach, called reactivity-directed analysis (RDA), which can be used to identify and prioritize those compounds that are of particular health concern. RDA combines approaches from analytical chemistry, molecular toxicology, data science, and environmental engineering to detect and identify toxic organic electrophiles, the largest class of known toxicants. RDA provides a new framework for identifying toxic byproducts and their precursors that can be used to optimize engineered treatment systems and minimize risks from toxic byproducts.

BIO:  Carsten Prasse, PhD is an Assistant Professor in the Department of Environmental Health and Engineering in the Johns Hopkins Whitening School of Engineering and the Bloomberg School of Public Health. Carsten received his Master’s degree in Environmental Sciences from the University of Bayreuth, Germany in 2008. In 2012 he obtained his PhD in Chemistry at the Federal Institute of Hydrology in Koblenz, Germany, under the guidance of Dr. Thomas Ternes for which he was honored with the dissertation award of the German Water Chemistry Society. After completing postdoctoral work at the Federal Institute of Hydrology and the University of California at Berkeley (research group of Dr. David Sedlak), he joined Johns Hopkins University in 2018.

Past Warren Lectures

Warren & Dexter Lecture with Constantin Christopoulos

Why We Need to Redefine Our Infrastructure Design Focus towards Resilience and a Few Examples of Novel Seismic Resilient Systems


Constantin Christopoulos, Ph.D., P.Eng. is Professor and Canada Research Chair in Seismic Resilience of Infrastructure and Director of Structural Testing Facilities, at the Department of Civil and Mineral Engineering, University of Toronto. He is also the Associate Editor, Canadian Journal of Civil Engineering.

ABSTRACT: Protecting our infrastructure is fundamentally important to public safety and to all sectors of our economy. Even if loss of life is averted when designing structures following modern codes, major catastrophic events such as earthquakes or hurricanes, may produce significant damage, economic loss, and place major strains on entire nations’ well-being. To address this challenge engineers are evolving their traditional methods of designing “safe” structures to achieving more “resilient” ones; the ultimate goal being to design and build a new generation of infrastructure that remains damageless and fully functional even after major disasters.

In this presentation, an overview of emerging broader risk and resilience analysis and decision-making frameworks will be presented to emphasize the benefits of our design focus shifting towards resilience. The presentation will then provide an overview of structural engineering research over the past 20 years at the University of Toronto that has been aimed at defining and validating a new set of systems that can provide the structural performance that is required in order to achieve resilience goals. The presentation will focus primarily on steel structures, but, given the limited damage that structural elements sustain in these systems, the findings are also applicable to structures constructed using numerous available materials. This research includes large-scale experimental and numerical research and discussions on design aspects. Finally, the presentation concludes with a discussion on how the implementation of these technologies, which has been lackadaisical at best in North America, can be accelerated to achieve a timely mass implementation of resilient structural systems.

Constantin Christopoulos is a Professor in the Department of Civil and Mineral Engineering at the University of Toronto. He completed his undergraduate and Maters degrees at Ecole Polytechnique in Montreal and his Ph.D. at the University of California at San Diego before joining U of T. He is the author of more than 150 technical papers, of two textbooks that are used in graduate courses in numerous countries, and named as an inventor in more than 40 international patents.  

Dr. Christopoulos is an associate member of the CSA-S16 Canadian Steel Code Committee, has been involved in a number of high-profile consulting projects involving the implementation of supplemental damping devices in structures, and has presented numerous lectures on advanced seismic engineering and damping systems with an emphasis on high-performance systems throughout the world.

Over the past 20 years, his research has pioneered the development and implementation of novel resilient self-centering structures. His team has also developed advanced damping technologies for both wind and seismic protection of high-rise buildings. He has also supervised research over the past decade on the use of cast steel in seismic engineering applications, which has led to numerous innovations. Professor Christopoulos has also been active in transferring research into practice through startup companies that he has co-founded with his former students.

Three Minute Thesis Contest

ABSTRACT: An 80,000 word Ph.D. thesis would take 9 hours to present. Their time limit... 3 minutes. The Three Minute Thesis (3MT) competition celebrates the exciting research conducted by graduate students in CEGE. The 3MT competition cultivates students’ academic, presentation, and research communication skills. The competition supports graduate student capacity to effectively explain their research in three minutes, in a language appropriate to a non-specialist audience. The (in-person & online) audience will determine the winner in an online vote. Bring your cell phone or laptop to vote! The winner and runner-up will represent our department at the college level 3MT completion on October 20th.

Featuring: CEGE graduate students from all research areas in the department

Warren Lecture with Xue Feng

Advancing Predictions of Ecosystem Responses through Ecohydrological Feedbacks

Abstract: Many ecosystems around the world are increasingly affected by climate change. The lifeforms within those ecosystems take up, store, and use carbon for growth and maintenance, such as plants that photosynthesize, or microbes that decompose soil carbon. Importantly, their metabolism and function are controlled by water. As a result, the ecohydrological processes that make water accessible to these lifeforms will not only control ecosystem responses, but also their contributions to climate change, by regulating how much carbon is released back into the atmosphere as greenhouse gasses.

My research group aims to quantitatively uncover how water shapes ecosystem response to climate change and use this knowledge to advance Earth system and watershed predictions. Understanding water-carbon interactions at the ecosystem scale is complicated by the variability of water across multiple timescales and the nonlinear responses to water across multiple spatial scales. In this presentation, I elaborate on our work in three contexts: (i) the hydrological controls on peatland carbon emissions, (ii) plant hydraulic regulation and forest responses to drought, and (iii) vegetation impacts on urban hydrology. Using statistical, computational, observational, and analytical tools, our work has shed light on ecohydrological feedbacks at local scales and improved carbon and water flux predictions at ecosystem scales.

Xue Feng is a McKnight Land-Grant Assistant Professor in the Department of Civil, Environmental, and Geo- Engineering, University of Minnesota. Feng conducts research at the Saint Anthony Falls Laboratory. 

Environmental Justice with Kimberly Jones

"Environmental justice: Role of science, engineering, and policy in ensuring equity in urban water systems"

ABSTRACT: Urban environments, particularly rapidly developing centers such as the Washington, D.C. area, with its close proximity to the Chesapeake Bay and its tributaries, are important testbeds to develop systemic, equitable access to environmental services such as green infrastructure and safe, reliable drinking water. Science and engineering solutions must be integrated with policy in order to conceptualize and implement solutions that meet the needs of disparate and competing jurisdictions. Importantly, these solutions must be effectively communicated to all stakeholders. In this talk,  Jones discusses various issues around environmental justice and equity in the water sector.

Dr. Kimberly L. Jones is Associate Provost and Professor of Civil and Environmental Engineering at Howard University in Washington, DC. She holds a B.S in Civil Engineering from Howard University, a M.S. in Civil and Environmental Engineering from the University of Illinois in Champaign, IL and a Ph.D. in Environmental Engineering from The Johns Hopkins University. Dr. Jones’ research interests include developing membrane processes for environmental applications, physical-chemical processes for water and wastewater treatment, remediation of emerging contaminants, global drinking water quality, environmental justice, and environmental nanotechnology.

Warren Lecture with Amir AghaKouchak

"Compound Hazards: Typology, Risk and Attribution"

Amir AghaKouchak
Civil and Environmental Engineering
University of California, Irvine

ABSTRACT: Ground-based observations and model simulations show substantial increases in extreme events including rainfall events, droughts, wildfires, hot spells, and heatwaves. A key step toward improving our societal resilience is to identify emerging patterns of climate extremes and natural hazards. This requires a better understanding of tempo-spatial characteristics of natural hazards and also the interactions between different hazards in a changing climate.  A combination of climate events (e.g., high temperatures and high humidity, or low precipitation and high temperatures) may cause a significant impact on the ecosystem and society, although individual events involved may not be severe extremes themselves – a notion known as a compound event (e.g., extreme rain over burned areas, combined ocean and terrestrial flooding). This presentation focuses on three different types of compound events including drought-heatwaves, sea level rise-terrestrial flooding, and meteorological-anthropogenic drought. AghaKouchak presents different methodological frameworks and perspectives for detecting, modeling, and risk assessment of compound and cascading events. AghaKouchak then discuss new frameworks for attribution of compound hazards.

Warren Lecture with Stefan Llewellyn Smith

"Convection beyond Rayleigh and Bénard"

Stefan G. Llewellyn Smith
Mechanical and Aerospace Engineering, University California San Diego

ABSTRACT: Rayleigh–Bénard convection is a canonical flow in fluid mechanics, with applications in industry, geophysics, astrophysics, and beyond. Investigations have examined linear and nonlinear stability as well as deriving analytical bounds on quantities of interest, while laboratory and numerical experiments have given insight into the behavior at large Rayleigh numbers. Generalizations such as the case of convection in porous media, as well as the effect of rotation and magnetic fields, can be found in textbooks. Smith discusses two less well-known cases. First, periodically-driven convection, in which the temperature along one boundary varies periodically in time. This case provides a model for heating of the waters of Lake Superior in Spring. Second, horizontal convection, in which the temperature (or buoyancy) varies along a horizontal boundary. This case offers a simplified model, for example, large-scale oceanic flows induced by horizontal buoyancy gradients. Smith reviews previous known results and presents more recent work on the stability and behavior of these flows.

Warren Lecture with Michael Levin

Michael Levin is an Assistant Professor in the Department of Civil, Environmental, and Geo- Engineering at the University of Minnesota. His research focuses on modeling connected autonomous vehicles (CAVs) and intelligent transportation systems to predict and optimize how these future technologies will affect travel demand and traffic flow. He uses traffic flow, transportation network analysis, and operations research methods to study these new technologies and their effects on cities.

Warren Lecture with Ameet Pinto

“Monitoring Microbes and Managing their Ecology in Drinking Water Systems”

ABSTRACT: Drinking water can contain tens of millions of diverse microbial cells in every liter. While most microbes in drinking water do not pose a human health risk, the presence of pathogenic microbes can have severe health implications and the underlying causes for microbial contamination can vary significantly. Developing strategies to avoid microbial contamination of drinking water is essential; there is also a need for a radical change in terms of how we detect and respond to failures. The existing paradigm of targeted microbial detection can result in sample-to-data time gap of more than two-three days. The application of molecular methods promises to change this, although key limitations (i.e., cost, expertise requirements, etc.) make their application for real-time microbial monitoring challenging. The ideal approach for monitoring drinking water would be to develop a sensitive and robust platform that can be deployed across the drinking water network and one that can stream data in real-time to consumers and to drinking water treatment plant operators. Pinto focuses on ongoing work on the development of low cost optical- and DNA sequencing-based methods for real-time microbial detection, quantitation, and characterization. Pinto also highlights important challenges that need to be overcome to realize the future of microbial monitoring in drinking water which will be real-time, autonomous, decentralized, and scalable.

Warren Lecture with Ahmed Elbanna

“Building the Earthquake Virtual Machine: Towards modeling sequence of earthquakes and aseismic slip (SEAS) with high resolution fault zone physics”

ABSTRACT: An active fault zone is home to a plethora of complex structural and geometric features that are expected to affect earthquake rupture nucleation, propagation, and arrest, as well as interseismic deformation, energy partitioning, radiation patterns, and focal mechanism interpretation. Due to the conundrum of scales involved in this problem, new advances in modeling, experiments, and field measurements are needed to reveal the interplay between fault zone inhomgeneities and source physics. In this talk, Elbanna applies FEBI, a hybrid finite element (FE)-spectral boundary integral (SBI) scheme, to explore modeling seismic and aseismic slip with high resolution fault zone physics. FEBI combines FEM and SBI through the consistent exchange of displacement and traction boundary conditions, thereby benefiting from the flexibility of FEM in handling problems with nonlinearities or small-scale heterogeneities and from the superior performance and accuracy of SBI. Time adaptivity to bridge the seismic and interseismic periods is achieved by implementing an alternating dynamic-quasidynamic formulations. Exact near-field truncation of the elastodynamic and elastostatic fields, enabled by the boundary integral formulation, allows FEBI to strategically allocate computational resources in a narrow region surrounding the fault zone that encompasses the small scale geometric or material complexities. Elbanna briefly presents three example applications of this new modeling framework: (1) Modeling dynamic ruptures in a fault zone with multiple discrete small-scale fractures, (2) Modeling of sequence of earthquakes and aseismic slip on a fault surface with evolving off-fault viscoplasticity, and (3) Modeling of sequence of earthquakes and aseismic slip on parallel faults that communicate with one another. The results suggest that fault zone pre-existing or evolving heterogeneities may significantly alter rupture characteristics, including rupture speed, energy dissipation, and high frequency generation, as well as seismicity pattern and fault stability. Elbanna discusses the implications of these results on the need for an integrated modeling-observation framework for understanding the co-evolution of fault, rheology, and stress in fault zones.

Warren Lecture with Mary F. Wheeler

"Dynamic adaptivity for coupled flow and geomechanics in unconventional reservoirs using a posteriori error estimation and spacetime modeling"

ABSTRACT: Coupled multiphase flow, geochemistry, and geomechanics models are receiving growing research interests for applications in unconventional reservoirs that include geological CO2 sequestration, geothermal and recently, hydrogen storage. These multiphysics and multiscale  simulations are computationally expensive and require preservation of physics, chemistry, and biology across spatial and temporal scales. In addition, these algorithms must be able to handle efficiently high performance computing, adaptive mesh refinement and highly nonlinear algebraic systems with rough coefficients. Additional computational issues include data extraction, optimization, uncertainty quantification, and machine learning. Wheeler discusses two high fidelity approaches that have been introduced for unconventional reservoirs that show promise for modeling reservoir energy production: a posteriori error estimation for coupling of multiphase and geomechanics and space time modeling for multiphase flow.

Mary F. Wheeler's expertise is in the numerical solution of coupled partial differential equations. Her research areas include modeling reactive and multiphase flows and parallel computations.