Dr. Robert P. Ewing (Toby)MS Crop Science, 1988, North Carolina State University BS Plant and Soil Science, 1982, University of Maine Staff Research Scientist ewing@iastate.edu |
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Dr. Robert P. Ewing (Toby)MS Crop Science, 1988, North Carolina State University BS Plant and Soil Science, 1982, University of Maine Staff Research Scientist ewing@iastate.edu |
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Research Interests:
Modeling flow and transport in porous media. My research concentration is in the use of percolation theory, network modeling, and random walk models in porous media. I'm particularly interested in the role of heterogeneity and spatial structure in determining material properties. Specific applications: simulation of initial DNAPL migration for improved prediction in expedited site characterization; movement and dissolution of NAPL ganglia (including enhanced oil recovery); sorption, desorption, and fate of organic chemicals; movement of radionuclides in low-connectivity rock matrices (e.g., Yucca Mountain). A topic I'm just starting to work in is coupled heat and water movement in soils.
Image and Signal Analysis. This has long been a secondary
research interest, particularly for discrimination and measurement of
objects and identification of patterns. Applications: root length measurement;
quantification
of color images; image classification from spectral signatures;
precision agriculture.
What I love about my job:
I get paid to ask questions. Can you beat that?! Of course, I'm also supposed to find ways to answer them... Working closely with graduate students. Recently I worked with Yanhui Hu in Chemical Engineering, developing a model of NAPL ganglia stability and dissolution. Currently I'm working with Pavel Iassonov in Geology, on a related topic in enhanced oil recovery. Teaching. I taught undergraduate earth sciences at Drake University for 2 years. It taught me a lot about the material, but more importantly, I found that I loved making the material mean something to others. I've also taught soil physics here at Iowa State. Reviewing papers and proposals. It can be time-consuming, but I like to think that I'm improving another person's work. Plus I learn a lot by studying other people's work. Programming. Turning strange ideas into specific instructions, then finding out how dumb I am when it doesn't work. A combination of "wow, this is cool" and ego crash. Try it. Data analysis. I used to be scared of math, but now it's my friend. the Earth Sciences. I still don't understand why EVERYONE isn't fascinated with soil, plants, weather, and the intricacies of the world around us. Wake up, go outside, and live! The people. Much of the fun of research and teaching is working with interesting people, growing with them in understanding and (one always hopes) maturity.
Service:
Reviewer for Advances in Water Resources, Water Resources Research, Journal of Hydrology, Agronomy Journal, Journal of Environmental Quality, Soil Science Society of America Journal, Vadose Zone Journal, NSF, DOE, and BARD. Awarded editor's citation for excellence in manuscript review for Soil Science Society of America Journal, 1999 and 2001, and for Vadose Zone Journal, 2004. Associate editor, division S-1 (soil physics), Soil Science Society of America Journal. Former associate editor (software) for Agronomy Journal, 1996-2001. Coordinator, Kirkham Conference 2000 Organizer, Mini-Symposium on Percolation in Porous Media at ETOPIM 6, 2002. Co-Convenor, session "Percolation and Related Processes in Porous Media", joint AGU/CGU meeting, Montreal, Canada, May 2004. Member, Community Advirsory Group (environmental accountability) for Ames Laboratory.
Hunt, A. G. And R. P. Ewing, On the vanishing of solute diffusion in porous media at a threshold moisture content, Soil Sci. Soc. Am. J. 67:1701-1702, 2003. Abstract.Ewing, R. P. and R. Horton, Scaling in diffusive transport, In Bridging Scales in Soil Physics (Ya. Pachepsky, Ed.), CRC Press, 2003. Abstract.
Ewing, R. P. and R. Horton, Diffusion in sparsely connected porespaces: Temporal and spatial scaling, Water Resour. Res. 38(12), 1285, doi 10.1029/2002WR001412 Abstract.
Hu, Q. and R. P. Ewing, Pore connectivity effects on solute transport in rocks, Proceedings of the symposium "Bridging the Gap between Measurement and Modeling", Berkeley, CA, March 25-28, 2002.
Ewing, Robert P. and Brian Berkowitz. Stochastic pore-scale growth models of DNAPL migration in porous media. Advances in Water Resources (special issue on pore-scale modeling) 24:309-323, 2001. Abstract.
Casey, F. X. M., R. P. Ewing, and R. Horton, Automated system for miscible displacement through soil of multiple volatile organic compounds, Soil Sci. 165 (11):841-847, 2000.
Ewing, R. P. and R. Horton. Discriminating Dyes in Soil with Color Image Analysis. Soil Science Society of America Journal 63:18-24, 1999.
Ewing, R. P. and R. Horton. Quantitative Color Image Analysis of Agronomic Images. Agronomy Journal 91:148-153, 1999.
Ewing, Robert P. and Brian Berkowitz, A generalized growth model for simulating initial migration of dense non-aqueous phase liquids. Water Resour. Res. 34:611-622, 1998.
Berkowitz, Brian and Robert P. Ewing, Percolation Theory and Network Modeling Applications in Soil Physics. Surveys in Geophysics 19:23-72, 1998
Kaspar, T. C. and Robert P. Ewing, ROOTEDGE: Software for Measuring Root Length from Desktop Scanner Images. Agron. J. 89:932-940, 1997.
Ewing, Robert P. and Dan B. Jaynes. Issues in Single Fracture Transport Modeling: Scales, Algorithms, and Grid Types. Water Resour. Res. 31:303-312, 1995.
Ewing, Robert P. and Thomas C. Kaspar. Accurate Perimeter and Length Measurement using a Boundary Chord Algorithm. J. Computer-Assisted Micros. 7:91-100, 1995.
Ewing, Robert P. and S. C. Gupta. Modeling Percolation Properties of Random Media Using a Domain Network. Water Resour. Res. 29:3169-3178, 1993.
Ewing, Robert P. and S. C. Gupta. Percolation and Permeability in Partially Structured Networks. Water Resour. Res. 29:3179-3188, 1993.