Description of trapped atoms in terms of pressure and volume: identification of those quantities and the first experimental results - Magalhães, Kílvia M. F.; Silva, Reginaldo Rocha da; Henn, Emanuel Alves de Lima; Romero-Rochin, Victor; Marcassa, Luís Gustavo; Bagnato, Vanderlei Salvador (International Conference on Photonic, Electronic and Atomic Collisions - ICPEAC, 2005)