All Publications

  • 3D zoning of barium in alkali feldspar AMERICAN MINERALOGIST Lubbers, J., Kent, A., Meisenheimer, D., Wildenschild, D. 2023; 108 (2): 297-311
  • Contact angle hysteresis: A new paradigm? ADVANCES IN WATER RESOURCES Behnoudfar, D., Dragila, M., Meisenheimer, D., Wildenschild, D. 2022; 161
  • Predicting the Effect of Relaxation on Interfacial Area Development in Multiphase Flow WATER RESOURCES RESEARCH Meisenheimer, D. E., Wildenschild, D. 2021; 57 (3)
  • Characterization of wetting using topological principles JOURNAL OF COLLOID AND INTERFACE SCIENCE Sun, C., McClure, J. E., Mostaghimi, P., Herring, A. L., Meisenheimer, D. E., Wildenschild, D., Berg, S., Armstrong, R. T. 2020; 578: 106-115


    Understanding wetting behavior is of great importance for natural systems and technological applications. The traditional concept of contact angle, a purely geometrical measure related to curvature, is often used for characterizing the wetting state of a system. It can be determined from Young's equation by applying equilibrium thermodynamics. However, whether contact angle is a representative measure of wetting for systems with significant complexity is unclear. Herein, we hypothesize that topological principles based on the Gauss-Bonnet theorem could yield a robust measure to characterize wetting.We introduce a macroscopic contact angle based on the deficit curvature of the fluid interfaces that are imposed by contacts with other immiscible phases. We perform sessile droplet simulations followed by multiphase experiments for porous sintered glass and Bentheimer sandstone to assess the sensitivity and robustness of the topological approach and compare the results to other traditional approaches.We show that the presented topological principle is consistent with thermodynamics under the simplest conditions through a variational analysis. Furthermore, we elucidate that at sufficiently high image resolution the proposed topological approach and local contact angle measurements are comparable. While at lower resolutions, the proposed approach provides more accurate results being robust to resolution-based effects. Overall, the presented concepts open new pathways to characterize the wetting state of complex systems and theoretical developments to study multiphase systems.

    View details for DOI 10.1016/j.jcis.2020.05.076

    View details for Web of Science ID 000570264600011

    View details for PubMedID 32521350

  • Exploring the effect of flow condition on the constitutive relationships for two-phase flow ADVANCES IN WATER RESOURCES Meisenheimer, D. E., McClure, J. E., Rivers, M. L., Wildenschild, D. 2020; 137
  • Reduction of 1,2,3-trichloropropane (TCP): pathways and mechanisms from computational chemistry calculations ENVIRONMENTAL SCIENCE-PROCESSES & IMPACTS Torralba-Sanchez, T. L., Bylaska, E. J., Salter-Blanc, A. J., Meisenheimer, D. E., Lyon, M. A., Tratnyek, P. G. 2020; 22 (3): 606-616


    The characteristic pathway for degradation of halogenated aliphatic compounds in groundwater or other environments with relatively anoxic and/or reducing conditions is reductive dechlorination. For 1,2-dihalocarbons, reductive dechlorination can include hydrogenolysis and dehydrohalogenation, the relative significance of which depends on various structural and energetic factors. To better understand how these factors influence the degradation rates and products of the lesser halogenated hydrocarbons (in contrast to the widely studied per-halogenated hydrocarbons, like trichloroethylene and carbon tetrachloride), density functional theory calculations were performed to compare all of the possible pathways for reduction and elimination of 1,2,3-trichloropropane (TCP). The results showed that free energies of each species and reaction step are similar for all levels of theory, although B3LYP differed from the others. In all cases, the reaction coordinate diagrams suggest that β-elimination of TCP to allyl chloride followed by hydrogenolysis to propene is the thermodynamically favored pathway. This result is consistent with experimental results obtained using TCP, 1,2-dichloropropane, and 1,3-dichloropropane in batch experiments with zerovalent zinc (Zn0, ZVI) as a reductant.

    View details for DOI 10.1039/c9em00557a

    View details for Web of Science ID 000526894100012

    View details for PubMedID 31990012

  • Optimizing pink-beam fast X-ray microtomography for multiphase flow in 3D porous media JOURNAL OF MICROSCOPY Meisenheimer, D. E., Rivers, M. L., Wildenschild, D. 2020; 277 (2): 100-106


    A fast pink-beam X-ray microtomography methodology was developed at the GSECARS 13-BMD beamline at the Advanced Photon Source to study multiphase flow in porous media. The white beam X-ray distribution of the Advanced Photon Source is modified using a 1-mm copper filter and the beam is reflected off a platinum mirror angled at 1.5 mrad, resulting in a pink beam with X-ray intensities predominately in the range of 40-60 keV. Bubble formation in the wetting phase and wettability alteration of the solid phase from x-ray exposure can be a problem with high flux and high energy beams, but the suggested pink-beam configuration mitigates these effects. With a 14-second acquisition time for capturing a complete dataset, the evolving fluid-fronts of nonequilibrium three-dimensional multiphase flow can be studied in real-time and the images contain adequate image contrast and quality to measure important multiphase quantities such as contact angles and interfacial areas. LAY DESCRIPTION: Understanding how fluids are transported through porous materials is pertinent to many important societal processes in the environment (e.g. groundwater flow for drinking water) and industry (e.g. drying of industrial materials such as pulp and paper). To develop accurate models and theories of this fluid transportation, experiments need to track fluids in 3-dimensions quickly. This is difficult to do as most materials are opaque and therefore cameras cannot capture fluid movement directly. But, with the help of x-rays, scientists can track fluids in 3D using an imaging technique called x-ray microtomography (μCT). Standard μCT takes about 15 minutes for one image which can produce blurry images if fluids are flowing quickly through the material. We present a technique, fast μCT, which uses a larger spectrum of x-rays than the standard technique and acquires a 3D image in 14 seconds. With the large amount of x-rays utilized in this technique, bubbles can start to form in the fluids from x-ray exposure. We optimized the utilized x-ray spectrum to limit bubble formation while still achieving a rapid 3D image acquisition that has adequate image quality and contrast. With this technique, scientists can study fluid transport in 3D porous materials in near real-time for the improvement of models used to ensure public and environmental health.

    View details for DOI 10.1111/jmi.12872

    View details for Web of Science ID 000513199000001

    View details for PubMedID 32022271

  • Sandy Soil Microaggregates: Rethinking Our Understanding of Hydraulic Function VADOSE ZONE JOURNAL Paradis, A., Brueck, C., Meisenheimer, D., Wanzek, T., Dragila, M. 2017; 16 (9)