A short video called "Jams in the Hopper" showcases the research of Junyao Tang, a graduate student in Prof. Bob Behringer's lab. Tang uses a two-dimensional simulated grain hopper to study how particles interact when they jam up in the mouth of a hopper. Jams are a big problem in industries that use hoppers to to move grains, berries, coffee beans, or other large particles. Behringer says, "The goal is to understand the nature of the flow, including the flow fields, the forces between grains, and the way in which a jam forms. When a jam occurs, the flow stops, something that is generally to be avoided in any practical grain flow device." This video was compiled by Ashley Yeager of the Duke Office of News and Communication. View it at "Duke On Demand" here.