Research

Stochastic and semi-analytical models of particle motion, memory, and breakthrough in porous media.

Doctoral Research

I investigate anomalous transport of elongated, deformable particles, including microplastic fibers, in microstructured and porous media. Anomalous, or non-Fickian, transport describes spreading and arrival patterns that depart from classical diffusion models.

I examine how obstacle geometry and heterogeneous waiting times shape particle retention and arrival. The objective is to connect local transport mechanisms with observable behavior at larger scales.

Research Questions & Methods

Particle-scale problem

Deformable fibers around circular obstacles

I investigate how particle deformation and circular obstacles affect the migration and retention of thread-like particles in perforated media.

Stochastic modeling

Waiting-time distributions and temporal memory

I use continuous-time random walks (CTRW) to represent particle motion as steps separated by waiting times. I study shifted generalized-gamma distributions and memory-dependent formulations to describe heterogeneous travel times and delayed transport.

Transport quantities

First-passage times and breakthrough dynamics

I analyze first-passage times—when particles first reach a boundary—and breakthrough curves—how particle arrivals vary over time—to characterize delays and the influence of geometric heterogeneity.

Mathematical approach

Semi-analytical methods for perforated domains

I develop semi-analytical formulations for diffusion and first-passage problems with circular boundaries and multiple cavities, using Laplace transforms, Fourier representations, modified Bessel functions, and multipole expansions.

Environmental Context

I also contribute to a review of continuum, pore-scale, and stochastic frameworks for microplastic transport. See Publications for the manuscript and its current status.

Transport in Porous Geometries

These figures from Prof. Mojdeh Rasoulzadeh’s research page illustrate particle-scale transport in the geometries that motivate my research.

Colored microfilament trajectories passing between randomly arranged circular obstacles.
Microfilament trajectories among circular obstacles. The colors distinguish trajectories over time; dark red indicates longer-time trajectories. Source: Mojdeh Rasoulzadeh, Research.
Five simulation panels showing deformable filaments moving through a channel with wavy walls and a colored velocity-magnitude field.
Filament motion in a channel with rough boundaries. Successive panels show filament configurations within the flow field; color represents velocity magnitude. Source: Mojdeh Rasoulzadeh, Research.

More about my work

Publications · Talks & presentations · Projects & skills