SOME NEW FEATURES OF INTERFACE ROUGHENING DYNAMICS IN PAPER WETTING, BURNING, AND RUPTURING EXPERIMENTS

The dynamics of interfaces growing in paper wetting, fracturing and bu rning processes is studied with use the same kinds of papers for different experiments. We were able to study five different types of kinetic roughening. Some new observations concerning the spatial temporal dynamics of rough interfaces are reported. Specifically, we found that the types of kinetic roughening, as well as the scaling exponents, are dependent on the paper structure and the mechanism of interface formation. Moreover, we have observed that the local roughness exponent of moving wet front logarithmically increases from 0.5 at initial stage up to the stationary value, achieved before front saturation. We also found that the stress-strain fracture behaviour of some kinds of paper exhibits a statistical self-affine invariance with scaling exponent, which is equal to the local roughness exponent of rupture line. The same exponent governs the changes in the stress-strain curve as the strain rate increases. This gives rise to the facture energy – time-to-fracture uncertainty relation, similar to the tim e-energy uncertainty relation in quantum mechanics. The physical implications of these points are discussed.