"Grain-Scale Dynamics and Force Transmission in Sticking and Slipping Granular Materials: Effects of Friction and Grain Shape"

The Physics Department welcomes Professor Ryan Kozlowski as our guest in our 2023-2024 Seminar Speaker Series!

Granular materials are ubiquitous in nature, from household table salt to mountainside boulders, silty river beds, and distant protoplanetary disks. Despite their prevalence in daily life and countless industries like agriculture and pharmaceuticals, the stability, flow, and responses of these materials to external perturbations are all active areas of physics research: unlike conventional solids or liquids, they often exist in non-equilibrium states, interact dissipatively, and have constituent particles of infinite variety in size, shape, and frictional properties. In this talk, I will present experiments specifically probing how grain shape and friction with boundaries influence the stick-slip dynamics of driven granular materials. In stick-slip dynamics, the granular material transitions back and forth between stable sticking periods and rapid, energy-releasing slip events, like the destructive sliding between tectonic plates that generates earthquakes.

Ryan Kozlowski's earned a PhD in physics at Duke University investigating jamming and stick-slip of granular materials, gradually gathering teaching experience as the years went by. After earning his PhD, Ryan became a visiting professor at Berea College, where he primarily taught courses across the physics curriculum but also began to explore silo discharge with undergraduates. Dr. Kozlowski is now an Assistant Professor of Physics at College of the Holy Cross, where he is teaching physics, learning to teach physics more effectively, and developing a research program focused on granular flows and silo discharge.