Reduction of clogging of vibrated grains passing through a narrow aperture by the addition of low-friction particles.

We study the flow of grains under vibration passing through a small aperture in two dimensions using discrete element method simulations. Such systems are prone to clogging and strategies to ease the flow are desirable in multiple applications. We show that the addition of low-friction particles to the system can reduce clogging and lead to an enhancement of the net flux of the original species.

Pedestrian evacuations with imitation of cooperative behavior.

We analyze the dynamics of room evacuation for mixed populations that include both competitive and cooperative individuals through numerical simulations using the social force model. Cooperative agents represent well-trained individuals who know how to behave in order to reduce risks within high-density crowds. We consider that competitive agents can imitate cooperative behavior when they are in close proximity to cooperators.