Lynn Schreyer - Academia.edu (original) (raw)

Papers by Lynn Schreyer

AGU Fall Meeting Abstracts, Dec 1, 2016

Water Resources Research, 2017

Solutes and suspended material often experience delays during exchange between phases one of whic... more Solutes and suspended material often experience delays during exchange between phases one of which may be moving. Consequently transport often exhibits combined effects of advection/dispersion, and delays associated with exchange between phases. Such processes are ubiquitous and include transport in porous/fractured media, watersheds, rivers, forest canopies, urban infrastructure systems, and networks. Upscaling approaches often treat the transport and delay mechanisms together, yielding macroscopic “anomalous transport” models. When interaction with the immobile phase is responsible for the delays, it is not the transport that is anomalous, but the lack of it, due to delays. We model such exchanges with a simple generalization of first‐order kinetics completely independent of transport. Specifically, we introduce a remobilization rate coefficient that depends on the time in immobile phase. Memory‐function formulations of exchange (with or without transport) can be cast in this framework, and can represent practically all time‐nonlocal mass balance models including multirate mass transfer and its equivalent counterparts in the continuous time random walk and time‐fractional advection dispersion formalisms, as well as equilibrium exchange. Our model can address delayed single‐/multievent remobilizations as in delay‐differential equations and periodic remobilizations that may be useful in sediment transport modeling. It is also possible to link delay mechanisms with transport if so desired, or to superpose an additional source of nonlocality through the transport operator. This approach allows for mechanistic characterization of the mass transfer process with measurable parameters, and the full set of processes representable by these generalized kinetics is a new open question.

Journal of Food Engineering, 2021

The objective of this work was to identify factors influencing cheese wear behaviors. Wear behavi... more The objective of this work was to identify factors influencing cheese wear behaviors. Wear behaviors of cheeses with different fat contents (40, 50, 52, and 54 FDM) were evaluated at different normal forces (0.5 and 0.7 N), sliding speeds (30 and 50 mm/s), and temperatures (5, 15, and 25 • C) every 15 d up to 60 d. All cheeses showed highest mass loss at 15 • C compared to that at 5 • C and 25 • C, while higher penetration depth was observed at 25 • C. Impact of normal force on mass loss and penetration depth was different at temperatures. Penetration depth and mass loss were greater at higher sliding speed in all cheeses but C54. Both mass loss and penetration depth increased with increasing aging time. Based on a box plot prediction model, cheeses with mass loss between 0.07 and 0.12 g were classified as "good sliceability"; mass loss above this range denoted "poor sliceability".

Journal of Food Engineering, 2021

The objective of this work was to identify factors influencing cheese wear behaviors. Wear behavi... more The objective of this work was to identify factors influencing cheese wear behaviors. Wear behaviors of cheeses with different fat contents (40, 50, 52, and 54 FDM) were evaluated at different normal forces (0.5 and 0.7 N), sliding speeds (30 and 50 mm/s), and temperatures (5, 15, and 25 • C) every 15 d up to 60 d. All cheeses showed highest mass loss at 15 • C compared to that at 5 • C and 25 • C, while higher penetration depth was observed at 25 • C. Impact of normal force on mass loss and penetration depth was different at temperatures. Penetration depth and mass loss were greater at higher sliding speed in all cheeses but C54. Both mass loss and penetration depth increased with increasing aging time. Based on a box plot prediction model, cheeses with mass loss between 0.07 and 0.12 g were classified as "good sliceability"; mass loss above this range denoted "poor sliceability".

International Journal of Rock Mechanics and Mining Sciences, 2021

Experimental data for porous media exhibit nonlinear pressure-volumetric strain relations and a s... more Experimental data for porous media exhibit nonlinear pressure-volumetric strain relations and a strong dependence on the Terzaghi pressure defined as confining pressure minus pore pressure . However, a clear explanation of why this pressure plays such a dominant role appears to be missing. Several authors have suggested that shear must be a significant factor in predicting change in porosity even for purely hydrostatic loading . Here this idea is explored in detail by analyzing a representative volume element consisting of a hollow sphere within a unit cube subjected only to hydrostatic compression. The results are presented independent of this particular geometry with the use of volume fractions . The analysis shows that the stress field within a relatively small region around a pore contains a measure of shear stress, called the Terzaghi shear, which is similar, but not equal, to the Terzaghi pressure. Shear strain in the hollow sphere does not affect the volumetric strain of the ...

Transport in Porous Media, 2021

Cilia, hair-like, organelles that are found in the respiratory tract (nasal cavity, pharynx, trac... more Cilia, hair-like, organelles that are found in the respiratory tract (nasal cavity, pharynx, trachea, and bronchi) rhythmically beat to clear mucus from the airways. Here, we formulate a novel model of fluid flow due to the movement of cilia, and in the companion paper, Part II, the model is numerically solved under simplifying assumptions using physical data from lung bronchi. The model is based on a porous media model, modified so that instead of fluid moving through a solid porous structure, the solid moves the fluid. Two macroscale regions are considered: a porous medium and a free-fluid domain. We use hybrid mixture theory to derive the governing equations so that we have a broader understanding of the assumptions used to obtain the model. The resulting model is the classical Brinkman Stokes equations generalized to account for the movement of the cilia. The model can be used as a prototype to determine the movement of fluid due to the given movement of a solid component of a p...

Advances in Water Resources, 2021

Abstract Using generalizations of the Cahn-Hilliard equation for modeling two-phase flow in porou... more Abstract Using generalizations of the Cahn-Hilliard equation for modeling two-phase flow in porous media at the pore scale has become popular due to its ability to capture interfacial effects by adding minimal complications. Here we use upscaled field equations and exploit the second law of thermodynamics in the spirit of rational thermodynamics to develop a framework that, for two phases at the macroscale, recovers the Korteweg stress tensor for the liquid phase, generalizes Darcy’s law, and recovers the classical Cahn-Hilliard equation. The corresponding results for three-phases at the macroscale are derived and are shown to be a generalization of Richards equation, and with appropriate simplifying assumptions are shown to recover the two-phase results. Simplifying the results appropriately produces a pore scale model for two liquid phases, and are shown to generalize previous works by Cueto-Felgueroso and Juanes and Boyer and Quintard et. al. The results are are also compared with the Cahn-Hilliard Brinkman equations, where it is noted that to be physically consistent the state variable should represent a physical quantity. One key aspect that distinguishes this formulation from others is that it captures the different energies of the three interfaces (gas-liquid, gas-solid, and liquid-solid) without introducing the corresponding quantities at the microscale (interfacial tension, contact angle, etc).

SIAM Journal on Applied Mathematics, 2021

Transport in Porous Media, 2020

Cilia are hair-like structures that move in unison with the purpose of propelling fluid. They are... more Cilia are hair-like structures that move in unison with the purpose of propelling fluid. They are found, for example, in the human bronchiole respiratory system and molluscs. Here, we validate a novel model of fluid flow due to the movement of cilia in a fixed computational domain. We consider two domains, a porous medium and a free-fluid domain and numerically solve the Stokes-Brinkman system of equations where the cilia geometry and velocity are input and the velocity of fluid due to the movement of cilia is determined. The cilia velocities and geometry are approximated using human lung cilia experimental data available in the literature. We use a mixed finite element method of Taylor-Hood type to calculate the fluid velocities in a three-dimensional domain. The results are validated in a simple case by comparison with an exact solution with good agreement. This problem can be used as a benchmark for the movement of fluid phases due to the self-propelled movement of a solid phase in a porous medium.

Water Resources Research, 2017

Multicomponent reactive transport involves the solution of a system of nonlinear coupled partial ... more Multicomponent reactive transport involves the solution of a system of nonlinear coupled partial differential equations. A number of methods have been developed to simplify the problem. In the case where all reactions are in instantaneous equilibrium and the mineral assemblage is constant in both space and time, de Simoni et al. (2007) provide an analytical solution that separates transport of aqueous components and minerals using scalar dissipation of ''mixing ratios'' between a number of boundary/initial solutions. In this approach, aqueous speciation is solved in conventional terms of primary and secondary species, and the mineral dissolution/precipitation rate is given in terms of the scalar dissipation and a chemical transformation term, both involving the secondary species associated with the mineral reaction. However, the identification of the secondary species is nonunique, and so it is not clear how to use the approach in general, a problem that is keenly manifest in the case of multiple minerals which may share aqueous ions. We address this problem by developing an approach to identify the secondary species required in the presence of one or multiple minerals. We also remedy a significant error in the de Simoni et al. (2007) approach. The result is a fixed and extended de Simoni et al. (2007) approach that allows construction of analytical solutions to multicomponent equilibrium reactive transport problems in which the mineral assemblage does not change in space or time and where the transport is described by closed-form solutions of the mixing ratios.

Transport in Porous Media, 2019

Porous materials are ubiquitous, from biological tissues (skin, cartilage, bones, heart tissue), ... more Porous materials are ubiquitous, from biological tissues (skin, cartilage, bones, heart tissue), to manufactured materials (paper, functional porous materials, batteries, drug delivery systems, diapers), to environmental materials (rocks, soils, plants). Because these materials are composed of multiple phases, the effects of flow, heat transfer, chemical reactions, and deformations including swelling and shrinking are more complex than that for a single phase such as a gas, liquid, or solid. The realization that porous materials, regardless of the application, have commonalities in modeling approaches, experimental methods, and numerical methods was the impetus of this journal, Transport in Porous Media (founded by Jacob Bear in 1986) and of the International Society for Porous Media (InterPore, interpore.org), which at its roots, originated in 2006. The growth of TIPM and of InterPore mirrors the explosive interest in porous media research that is now recognized as a field of research in and of itself. It is in the honor of InterPore's 10th anniversary, celebrated at the InterPore 10th Annual Meeting and Jubilee in 2018 in New Orleans, USA, that this special issue was conceived. The goal of this issue is to help researchers new to porous materials or to certain aspects of porous materials jump into the field as quickly as possible by providing a suite of articles by some of the leading experts in their respective fields in a field-independent manner. We next summarize the history of InterPore and then introduce the contents of this special issue. InterPore did not just begin one day with a group of people deciding to start an international society. The idea of such a society grew organically, with its origins in a proposal for a joint international graduate research program proposal from the

Transport in Porous Media, 2019

Charged porous media are pervasive, and modeling such systems is mathematically and computational... more Charged porous media are pervasive, and modeling such systems is mathematically and computationally challenging due to the highly coupled hydrodynamic and electrochemical interactions caused by the presence of charged solid surfaces, ions in the fluid, and chemical reactions between the ions in the fluid and the solid surface. In addition to the microscopic physics, applied external potentials, such as hydrodynamic, electrical, and chemical potential gradients, control the macroscopic dynamics of the system. This paper aims to give fresh overview of modeling pore-scale and Darcy-scale coupled processes for different applications. At the microscale, fundamental microscopic concepts and corresponding mass and momentum balance equations for charged porous media are presented. Given the highly coupled nonlinear physiochemical processes in charged porous media as well as the huge discrepancy in length scales of these physiochemical phenomena versus the application, numerical simulation of these processes at the Darcy scale is even more challenging than the direct pore-scale simulation of multiphase flow in porous media. Thus, upscaling the microscopic processes up to the Darcy scale is essential and highly required for large-scale applications. Hence, we provide and discuss Darcy-scale porous medium theories obtained using the hybrid mixture theory and homogenization along with their corresponding assumptions. Then, application of these theoretical developments in clays, batteries, enhanced oil recovery, and biological systems is discussed.

Computational Geosciences, 2019

A systematic development of the macroscopic field equations (conservation of mass, linear and ang... more A systematic development of the macroscopic field equations (conservation of mass, linear and angular momentum, energy, and Maxwell's equations) for a multiphase, multicomponent medium is presented. It is assumed that speeds involved are much slower than the speed of light and that the magnitude of the electric field significantly dominates over the magnetic field so that the electroquasistatic form of Maxwell's equations applies. A mixture formulation is presented for each phase and then averaged to obtain the macroscopic formulation. Species electric fields are considered, however it is assumed that it is the total electric field which contributes to the electrically induced forces and energy. The relationships between species and bulk phase variables and the macroscopic and microscopic variables are given explicitly. The resulting field equations are of relevance to many practical applications including, but not limited to, swelling clays (smectites), biopolymers, biological membranes, pulsed electrophoresis, and chromatography.

Water Resources Research, 2016

 Users may download and print one copy of any publication from the public portal for the purpose... more  Users may download and print one copy of any publication from the public portal for the purpose of private study or research.  You may not further distribute the material or use it for any profit-making activity or commercial gain  You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

Transport in Porous Media, 2016

In a lifetime of work, Dr. Olivier Coussy developed a complete theoretic framework for porous med... more In a lifetime of work, Dr. Olivier Coussy developed a complete theoretic framework for porous media that researchers in a broad range of fields including (but not limited to) concrete, hydrology, swelling clay, and \hbox {CO}_2$$CO2-induced swelling of coal have continued to use as a foundation. However, in some of these works where a framework is developed for a deformable porous media, a dissipative inequality is assumed that implicitly results in a thermodynamical form of liquid pressure that is inconsistent with the classical thermodynamical form of pressure found in thermodynamic textbooks for a single phase. In this note, we compare this definition of pressure with those developed in other mixture-theoretic frameworks and demonstrate this inconsistency by mathematically showing that the thermodynamic quantity is most closely related to the solid pressure and explain how this inconsistency came about.

Transport in Porous Media, 2004

In a thermodynamic setting for a single phase (usually fluid), the thermodynamically defined pres... more In a thermodynamic setting for a single phase (usually fluid), the thermodynamically defined pressure, involving the change in energy with respect to volume, is often assumed to be equal to the physically measurable pressure, related to the trace of the stress tensor. This assumption holds under certain conditions such as a small rate of deformation tensor for a fluid. For

AGU Fall Meeting Abstracts, Dec 1, 2016

Water Resources Research, 2017

Solutes and suspended material often experience delays during exchange between phases one of whic... more Solutes and suspended material often experience delays during exchange between phases one of which may be moving. Consequently transport often exhibits combined effects of advection/dispersion, and delays associated with exchange between phases. Such processes are ubiquitous and include transport in porous/fractured media, watersheds, rivers, forest canopies, urban infrastructure systems, and networks. Upscaling approaches often treat the transport and delay mechanisms together, yielding macroscopic “anomalous transport” models. When interaction with the immobile phase is responsible for the delays, it is not the transport that is anomalous, but the lack of it, due to delays. We model such exchanges with a simple generalization of first‐order kinetics completely independent of transport. Specifically, we introduce a remobilization rate coefficient that depends on the time in immobile phase. Memory‐function formulations of exchange (with or without transport) can be cast in this framework, and can represent practically all time‐nonlocal mass balance models including multirate mass transfer and its equivalent counterparts in the continuous time random walk and time‐fractional advection dispersion formalisms, as well as equilibrium exchange. Our model can address delayed single‐/multievent remobilizations as in delay‐differential equations and periodic remobilizations that may be useful in sediment transport modeling. It is also possible to link delay mechanisms with transport if so desired, or to superpose an additional source of nonlocality through the transport operator. This approach allows for mechanistic characterization of the mass transfer process with measurable parameters, and the full set of processes representable by these generalized kinetics is a new open question.

Journal of Food Engineering, 2021

The objective of this work was to identify factors influencing cheese wear behaviors. Wear behavi... more The objective of this work was to identify factors influencing cheese wear behaviors. Wear behaviors of cheeses with different fat contents (40, 50, 52, and 54 FDM) were evaluated at different normal forces (0.5 and 0.7 N), sliding speeds (30 and 50 mm/s), and temperatures (5, 15, and 25 • C) every 15 d up to 60 d. All cheeses showed highest mass loss at 15 • C compared to that at 5 • C and 25 • C, while higher penetration depth was observed at 25 • C. Impact of normal force on mass loss and penetration depth was different at temperatures. Penetration depth and mass loss were greater at higher sliding speed in all cheeses but C54. Both mass loss and penetration depth increased with increasing aging time. Based on a box plot prediction model, cheeses with mass loss between 0.07 and 0.12 g were classified as "good sliceability"; mass loss above this range denoted "poor sliceability".

Journal of Food Engineering, 2021

The objective of this work was to identify factors influencing cheese wear behaviors. Wear behavi... more The objective of this work was to identify factors influencing cheese wear behaviors. Wear behaviors of cheeses with different fat contents (40, 50, 52, and 54 FDM) were evaluated at different normal forces (0.5 and 0.7 N), sliding speeds (30 and 50 mm/s), and temperatures (5, 15, and 25 • C) every 15 d up to 60 d. All cheeses showed highest mass loss at 15 • C compared to that at 5 • C and 25 • C, while higher penetration depth was observed at 25 • C. Impact of normal force on mass loss and penetration depth was different at temperatures. Penetration depth and mass loss were greater at higher sliding speed in all cheeses but C54. Both mass loss and penetration depth increased with increasing aging time. Based on a box plot prediction model, cheeses with mass loss between 0.07 and 0.12 g were classified as "good sliceability"; mass loss above this range denoted "poor sliceability".

International Journal of Rock Mechanics and Mining Sciences, 2021

Experimental data for porous media exhibit nonlinear pressure-volumetric strain relations and a s... more Experimental data for porous media exhibit nonlinear pressure-volumetric strain relations and a strong dependence on the Terzaghi pressure defined as confining pressure minus pore pressure . However, a clear explanation of why this pressure plays such a dominant role appears to be missing. Several authors have suggested that shear must be a significant factor in predicting change in porosity even for purely hydrostatic loading . Here this idea is explored in detail by analyzing a representative volume element consisting of a hollow sphere within a unit cube subjected only to hydrostatic compression. The results are presented independent of this particular geometry with the use of volume fractions . The analysis shows that the stress field within a relatively small region around a pore contains a measure of shear stress, called the Terzaghi shear, which is similar, but not equal, to the Terzaghi pressure. Shear strain in the hollow sphere does not affect the volumetric strain of the ...

Transport in Porous Media, 2021

Cilia, hair-like, organelles that are found in the respiratory tract (nasal cavity, pharynx, trac... more Cilia, hair-like, organelles that are found in the respiratory tract (nasal cavity, pharynx, trachea, and bronchi) rhythmically beat to clear mucus from the airways. Here, we formulate a novel model of fluid flow due to the movement of cilia, and in the companion paper, Part II, the model is numerically solved under simplifying assumptions using physical data from lung bronchi. The model is based on a porous media model, modified so that instead of fluid moving through a solid porous structure, the solid moves the fluid. Two macroscale regions are considered: a porous medium and a free-fluid domain. We use hybrid mixture theory to derive the governing equations so that we have a broader understanding of the assumptions used to obtain the model. The resulting model is the classical Brinkman Stokes equations generalized to account for the movement of the cilia. The model can be used as a prototype to determine the movement of fluid due to the given movement of a solid component of a p...

Advances in Water Resources, 2021

Abstract Using generalizations of the Cahn-Hilliard equation for modeling two-phase flow in porou... more Abstract Using generalizations of the Cahn-Hilliard equation for modeling two-phase flow in porous media at the pore scale has become popular due to its ability to capture interfacial effects by adding minimal complications. Here we use upscaled field equations and exploit the second law of thermodynamics in the spirit of rational thermodynamics to develop a framework that, for two phases at the macroscale, recovers the Korteweg stress tensor for the liquid phase, generalizes Darcy’s law, and recovers the classical Cahn-Hilliard equation. The corresponding results for three-phases at the macroscale are derived and are shown to be a generalization of Richards equation, and with appropriate simplifying assumptions are shown to recover the two-phase results. Simplifying the results appropriately produces a pore scale model for two liquid phases, and are shown to generalize previous works by Cueto-Felgueroso and Juanes and Boyer and Quintard et. al. The results are are also compared with the Cahn-Hilliard Brinkman equations, where it is noted that to be physically consistent the state variable should represent a physical quantity. One key aspect that distinguishes this formulation from others is that it captures the different energies of the three interfaces (gas-liquid, gas-solid, and liquid-solid) without introducing the corresponding quantities at the microscale (interfacial tension, contact angle, etc).

SIAM Journal on Applied Mathematics, 2021

Transport in Porous Media, 2020

Cilia are hair-like structures that move in unison with the purpose of propelling fluid. They are... more Cilia are hair-like structures that move in unison with the purpose of propelling fluid. They are found, for example, in the human bronchiole respiratory system and molluscs. Here, we validate a novel model of fluid flow due to the movement of cilia in a fixed computational domain. We consider two domains, a porous medium and a free-fluid domain and numerically solve the Stokes-Brinkman system of equations where the cilia geometry and velocity are input and the velocity of fluid due to the movement of cilia is determined. The cilia velocities and geometry are approximated using human lung cilia experimental data available in the literature. We use a mixed finite element method of Taylor-Hood type to calculate the fluid velocities in a three-dimensional domain. The results are validated in a simple case by comparison with an exact solution with good agreement. This problem can be used as a benchmark for the movement of fluid phases due to the self-propelled movement of a solid phase in a porous medium.

Water Resources Research, 2017

Multicomponent reactive transport involves the solution of a system of nonlinear coupled partial ... more Multicomponent reactive transport involves the solution of a system of nonlinear coupled partial differential equations. A number of methods have been developed to simplify the problem. In the case where all reactions are in instantaneous equilibrium and the mineral assemblage is constant in both space and time, de Simoni et al. (2007) provide an analytical solution that separates transport of aqueous components and minerals using scalar dissipation of ''mixing ratios'' between a number of boundary/initial solutions. In this approach, aqueous speciation is solved in conventional terms of primary and secondary species, and the mineral dissolution/precipitation rate is given in terms of the scalar dissipation and a chemical transformation term, both involving the secondary species associated with the mineral reaction. However, the identification of the secondary species is nonunique, and so it is not clear how to use the approach in general, a problem that is keenly manifest in the case of multiple minerals which may share aqueous ions. We address this problem by developing an approach to identify the secondary species required in the presence of one or multiple minerals. We also remedy a significant error in the de Simoni et al. (2007) approach. The result is a fixed and extended de Simoni et al. (2007) approach that allows construction of analytical solutions to multicomponent equilibrium reactive transport problems in which the mineral assemblage does not change in space or time and where the transport is described by closed-form solutions of the mixing ratios.

Transport in Porous Media, 2019

Porous materials are ubiquitous, from biological tissues (skin, cartilage, bones, heart tissue), ... more Porous materials are ubiquitous, from biological tissues (skin, cartilage, bones, heart tissue), to manufactured materials (paper, functional porous materials, batteries, drug delivery systems, diapers), to environmental materials (rocks, soils, plants). Because these materials are composed of multiple phases, the effects of flow, heat transfer, chemical reactions, and deformations including swelling and shrinking are more complex than that for a single phase such as a gas, liquid, or solid. The realization that porous materials, regardless of the application, have commonalities in modeling approaches, experimental methods, and numerical methods was the impetus of this journal, Transport in Porous Media (founded by Jacob Bear in 1986) and of the International Society for Porous Media (InterPore, interpore.org), which at its roots, originated in 2006. The growth of TIPM and of InterPore mirrors the explosive interest in porous media research that is now recognized as a field of research in and of itself. It is in the honor of InterPore's 10th anniversary, celebrated at the InterPore 10th Annual Meeting and Jubilee in 2018 in New Orleans, USA, that this special issue was conceived. The goal of this issue is to help researchers new to porous materials or to certain aspects of porous materials jump into the field as quickly as possible by providing a suite of articles by some of the leading experts in their respective fields in a field-independent manner. We next summarize the history of InterPore and then introduce the contents of this special issue. InterPore did not just begin one day with a group of people deciding to start an international society. The idea of such a society grew organically, with its origins in a proposal for a joint international graduate research program proposal from the

Transport in Porous Media, 2019

Charged porous media are pervasive, and modeling such systems is mathematically and computational... more Charged porous media are pervasive, and modeling such systems is mathematically and computationally challenging due to the highly coupled hydrodynamic and electrochemical interactions caused by the presence of charged solid surfaces, ions in the fluid, and chemical reactions between the ions in the fluid and the solid surface. In addition to the microscopic physics, applied external potentials, such as hydrodynamic, electrical, and chemical potential gradients, control the macroscopic dynamics of the system. This paper aims to give fresh overview of modeling pore-scale and Darcy-scale coupled processes for different applications. At the microscale, fundamental microscopic concepts and corresponding mass and momentum balance equations for charged porous media are presented. Given the highly coupled nonlinear physiochemical processes in charged porous media as well as the huge discrepancy in length scales of these physiochemical phenomena versus the application, numerical simulation of these processes at the Darcy scale is even more challenging than the direct pore-scale simulation of multiphase flow in porous media. Thus, upscaling the microscopic processes up to the Darcy scale is essential and highly required for large-scale applications. Hence, we provide and discuss Darcy-scale porous medium theories obtained using the hybrid mixture theory and homogenization along with their corresponding assumptions. Then, application of these theoretical developments in clays, batteries, enhanced oil recovery, and biological systems is discussed.

Computational Geosciences, 2019

A systematic development of the macroscopic field equations (conservation of mass, linear and ang... more A systematic development of the macroscopic field equations (conservation of mass, linear and angular momentum, energy, and Maxwell's equations) for a multiphase, multicomponent medium is presented. It is assumed that speeds involved are much slower than the speed of light and that the magnitude of the electric field significantly dominates over the magnetic field so that the electroquasistatic form of Maxwell's equations applies. A mixture formulation is presented for each phase and then averaged to obtain the macroscopic formulation. Species electric fields are considered, however it is assumed that it is the total electric field which contributes to the electrically induced forces and energy. The relationships between species and bulk phase variables and the macroscopic and microscopic variables are given explicitly. The resulting field equations are of relevance to many practical applications including, but not limited to, swelling clays (smectites), biopolymers, biological membranes, pulsed electrophoresis, and chromatography.

Water Resources Research, 2016

 Users may download and print one copy of any publication from the public portal for the purpose... more  Users may download and print one copy of any publication from the public portal for the purpose of private study or research.  You may not further distribute the material or use it for any profit-making activity or commercial gain  You may freely distribute the URL identifying the publication in the public portal If you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediately and investigate your claim.

Transport in Porous Media, 2016

In a lifetime of work, Dr. Olivier Coussy developed a complete theoretic framework for porous med... more In a lifetime of work, Dr. Olivier Coussy developed a complete theoretic framework for porous media that researchers in a broad range of fields including (but not limited to) concrete, hydrology, swelling clay, and \hbox {CO}_2$$CO2-induced swelling of coal have continued to use as a foundation. However, in some of these works where a framework is developed for a deformable porous media, a dissipative inequality is assumed that implicitly results in a thermodynamical form of liquid pressure that is inconsistent with the classical thermodynamical form of pressure found in thermodynamic textbooks for a single phase. In this note, we compare this definition of pressure with those developed in other mixture-theoretic frameworks and demonstrate this inconsistency by mathematically showing that the thermodynamic quantity is most closely related to the solid pressure and explain how this inconsistency came about.

Transport in Porous Media, 2004

In a thermodynamic setting for a single phase (usually fluid), the thermodynamically defined pres... more In a thermodynamic setting for a single phase (usually fluid), the thermodynamically defined pressure, involving the change in energy with respect to volume, is often assumed to be equal to the physically measurable pressure, related to the trace of the stress tensor. This assumption holds under certain conditions such as a small rate of deformation tensor for a fluid. For