  A model is presented for the characterization of dissipative effects on
highly nonlinear waves in one-dimensional dry granular media. The model
includes three terms: Hertzian, viscoelastic, and a term proportional to the
square of the relative velocity of particles. The model outcomes are confronted
with different experiments where the granular system is subject to several
constraints for different materials. Excellent qualitative and quantitative
agreement between theory and experiments is found.
