“Mathematical Modeling of the Transport of Pollutants from Hazardous Waste Landfills,” Workshop on Land Disposal of Hazardous Wastes, Cambridge University, Cambridge, England, September 9-11, 1987.
“Use of the Method of Moments to Study Reactive Solute Transport in Aggregated Porous Media,” Symposium on the Transport of Water and Solutes in Macropores, Soil Science Society of America, Annual Meeting, Anaheim, California, Nov. 27-Dec. 2, 1988.
“Transport of Adsorbing Contaminants in Heterogeneous Aquifers,” California Institute of Technology, Environmental Engineering Science, Dec. 1, 1988.
“Numerical Simulation of the Transport of Adsorbing Solutes in Heterogeneous Aquifers,” VIII International Conference on Computational Methods in Water Resources, Venice, June 11-15, 1990.
“Transport of Reactive Solvents in Randomly Heterogeneous Porous Media,” University of Waterloo, Institute for Groundwater Research, March 19, 1991.
“A Method for Locating Groundwater Quality Monitoring Wells at Hazardous Waste Disposal Facilities,” Lewis G. Weeks Lecture, University of Wisconsin-Madison, Department of Geology and Geophysics, Oct. 11, 1991.
“Modeling the Impact of Soil Heterogeneity on In Situ Bioremediation,” Workshop on Mathematical Issues in Bioremediation, sponsored by the Center for Nonlinear Studies, Los Alamos National Laboratory and the Society for Industrial and Applied Mathematics, June 11-13, 1997.
“Characterization of Traveling Waves and Analytical Estimation of Pollutant Removal in One-Dimensional Subsurface Bioremediation Modeling,” Fourth SIAM Conference on Mathematical and Computational Issues in the Geosciences, Albuquerque, NM, June 16-19, 1997.
“Parameter Sensitivity in Multicomponent Reactive Transport Models,” Plenary Presentation at A Workshop on Reactive Transport Modeling, Environmental Molecular Sciences Laboratory, Pacific Northwest Laboratory, Oct. 29-Nov. 1, 1997.
“Transport and Reaction During Enhanced In-Situ Bioremediation in Stratified Aquifers,” Special Session on Dilution and Mixing in Intrinsic and Enhanced Bioremediation, American Geophysical Union, Fall Meeting, December 1998.
“Transport, Mixing, and Reaction Processes in Aquifer Bioremediation,” Workshop in Mathematics and the Geosciences, sponsored by the National Science Foundation and the Dept. of Mathematics and Statistics, University of Nebraska, Lincoln, March, 1999.
“New Methods for Investigation of Pore-Scale Processes in Groundwater Transport,” Illinois State Water Survey, February 2000.
“Modeling Mixing Processes in Simulation of Halogenated Hydrocarbons in Heterogeneous Aquifers,” Dupont Expert Workshop on Modeling and Management of Emerging Environmental Issues, Penn State Great Valley, July 2000.
“Challenges in Field-Scale Reactive Transport Modeling,” DOE Natural and Accelerated Bioremediation Research (NABIR) Workshop on Biogeochemical Modeling, Penn State University, October 21-23, 2001.
”Newton-Krylov Methods for Fully Coupled Solution of Biogeochemical Reactive Transport Problems on Parallel Computers,” SIAM Conference on Mathematical and Computational Issues in the Geosciences, Austin TX, March 2003.
“The Influence of Pore-Scale Mixing on Biodegradation and Biomass Growth,” Department of Geography and Environmental Engineering, Johns Hopkins University, February 2004.
“Comparison of Pore-Scale and Continuum Models of Substrate Biodegradation Under Transverse Mixing Conditions ,” Institute for Geosciences, University of Tuebingen, April 2005.
“Comparison of Pore-Scale and Continuum Models of Substrate Biodegradation Under Transverse Mixing Conditions ,” Geological Institute, University of Copenhagen, May 2005.
“Modeling Mixing-Controlled Biogeochemical Reactions from the Pore to Continuum Scale,” SIAM Conference on Mathematical and Computational Issues in the Geosciences, Santa Fe, NM, March 2007.
“Merging Physically-Based and Data-Driven Models to Improve Prediction of Groundwater Systems,” IHE-UNESCO, Delft, The Netherlands, June 2007.
“Impact of Mixing-Controlled Reactions on the Fate and Transport of Groundwater Contaminants: Modeling and Pore-Scale Experiments,” Department of Mechanical, Aerospace and Structural Engineering, Washington University St. Louis, November 1, 2007.
“Dealing with Local Bias in Calibrated Groundwater Flow Models: A Case Study of the Republican River Basin,” Keynote Presentation, MODFLOW and More 2008 Conference, International Ground water Modeling Center, Golden CO, May 18-21 2008.
“Merging Physically-Based and Data-Driven Models to Improve Prediction of Groundwater Systems,” CIMA Research Foundation, Universita di Genova, Italy, September 19, 2008.
“A Complementary Modeling Framework to Quantify and Reduce Groundwater Flow Model Uncertainty,” Session H31: Uncertainty Analysis in Groundwater Modeling, Fall Meeting, American Geophysical Union, Dec. 2008.
“Use of Ground Water Models for Resource Assessment of Watersheds affected by Irrigation Pumping: Impact of Model Input and Parameter Uncertainty,” National Ground Water Association, Ground Water Summit, Tucson AZ, April 20-22, 2009.
“Improving Prediction of Regional-Scale Groundwater Flow Models throughExploratory Data Analysis and Complementary Modeling,” MODFLOW and More 2011: Integrated Hydrologic Modeling, June 5-8, 2011.
“Impact of Mixing-Controlled Reactions on Subsurface Fate and Transport: Pore-Scale Simulaiton and Experiments,” University of Notre Dame, Department of Civil and Environmental Engineering, Feb. 7, 2012.
“Impact of Mixing-Controlled Reactions on Subsurface Fate and Transport: Pore-Scale Simulaiton and Experiments,” MIT, Department of Civil and Environmental Engineering, Mar. 1, 2012.
“Modeling and Experimental Investigations of Mixing-Controlled Geochemical and Biological Reactions at the Pore Scale,” Session H42: Recent Advances in Theoretical, Numerical, and Experimental Methods in Flow and Transport in Porous Media , Fall Meeting, American Geophysical Union, Dec. 20012.
“Multiphase flow lattice Boltzmann modeling including geochemistry,” Pore Scale Modeling Workshop, Shell Global Solutions Int., Rijswijk, the Netherlands, Jan 29-29, 2013.
“Multicomponent Reactive Transport: First-order Decay to Multicomponent Biogeochemistry, Continuum to Pore, Algorithms to Applications,” XX International Conference, Computational Methods in Water Resources, Stuttgart, Germany, June 10-13, 2014.
“Combining Physically-Based and Data-Driven Models to Improve Prediction of Regional Groundwater Flow,” Iowa Institute for Hydraulic Research, March 6, 2015.
“Pore-scale simulation of two-phase flow with applications to geological sequestration of CO2,” Fifteenth Pan American Congress of Applied Mechanics, Univ. of Illinois, May, 2015.
“A Bayesian Approach to Improved Calibration and Prediction of Groundwater Models with Structural Error,” MODFLOW and More, Golden CO, May 2015.
“Numerical simulation of multiphase flow: from pore to core scale (and beyond),” International Annual Workshop. CO2 Storage Division of the I2CNER (International Institute for Carbon-Neutral Energy Research), Kyushu University, Japan, Feb. 4, 2016.
“Simulation of Two-Phase Flow in Porous Media: Research at the Illinois Center for Geological Sequestration of CO2,” Department of Petroleum and Geosystems Engineering, University of Texas, Austin, April 4, 2016.
“Computationally Efficient Methods for Modeling Diffusion and Reaction in Low Permeability Zones in Field-Scale Simulations using MODFLOW/MT3D/RT3D,” MODFLOW and More, Golden, CO, May 2017.
“Combining Physically-Based and Data-Driven Models for Regional Groundwater Flow Forecasting,” Keynote Lecture, 5th International Conference Novel Methods for Subsurface Characterization and Monitoring, TU Dresden, June 6-9, 2017.
”Using Multiscale Modeling to Study Coupled Flow, Transport, Reaction and Biofilm Growth Processes in Porous Media,” Special Session ”Coupled thermo-hydro-mechanical-chemical-biological processes in subsurface systems,” American Geophysical Union Meeting, Dec. 2017.
“Combining Physically-Based and Data-Driven Models for Regional Groundwater Flow Forecasting,” Conference on Machine Learning in Solid Earth Geoscience, Center for Nonlinear Studies, Los Alamos National Laboratory, Feb. 20-22, 2018.
“Combining Physically-Based and Data-Driven Models to Improve Forecasts of Regional Groundwater Flow,” Univ. of Texas, Austin, Dept. of Civil, Environmental and Architectural Engineering, April, 2018.
”A Lagrangian scheme to model subgrid-scale mixing in heterogeneous porous media,” Tenth Annual Conference of the International Society for Porous Media, New Orleans, May 7-11, 2018.
“ Are full tensors making you cross? How to handle all the negativity and stay positive with MT3DMS ,” MODFLOW and More, Golden, Colorado, June, 2019.
“Pore-scale simulation of two-phase flow for geologic sequestration of CO2: Great expectations, sober reality,” Keynote, XXII International Conference on Computational Methods in Water Resources, Dec. 2020.