title: Spontaneous imbibition experiment in newspaper sheets.
abstract: We study the behavior of an ink-paper interface in a spontaneous imbibition experiment as a function of time and paper orientation. To characterize the interface roughness the growth beta and Hurst H exponents (calculated using the root mean square interface width W) and the H{q} scaling exponent (calculated using the qth order height-height correlation function) are used. Our results indicate that the values of H and H{q} depend on the orientation of the paper sheets, while beta does not, and that the interface exhibits a multiaffine character during all its evolution.
authors.affiliation: Departamento de Física, Universidade Federal de Viçosa, 36571-000, Viçosa, Minas Gerais, Brazil.
authors.forename: A M
authors.initials: AM
authors.lastname: Miranda
authors.forename: I L
authors.initials: IL
authors.lastname: Menezes-Sobrinho
authors.forename: M S
authors.initials: MS
authors.lastname: Couto