title: Droplets of fine powders running uphill by vertical vibration.
abstract: We observe "droplets" forming when an inclined surface initially covered by fine powders is vibrated vertically. Droplets move uphill in the direction of maximum local slope. The speed of droplets is nearly independent on their size whereas it is an increasing function of the plate acceleration and inclination. By evacuating the container we show that the interstitial air flow plays an important role on droplets forming and their drift.
authors.affiliation: Departamento de Física Universidad de Santiago de Chile and Center for Advanced Interdisciplinary Research in Materials, CIMAT, Avenida Ecuador 3493, Casilla 307, Correo 2, Santiago-Chile.
authors.forename: Leonardo
authors.initials: L
authors.lastname: Caballero
authors.forename: Francisco
authors.initials: F
authors.lastname: Melo
mesh_terms: D003198:Computer Simulation; D017276:Friction; D006112:Gravitation; D044085:Microfluidics / Q000379:methods*; D008956:Models, Chemical; D008962:Models, Theoretical; D011208:Powders / Q000737:chemistry*; D014732:Vibration
chemical_list: D011208:Powders