The close spacing of electron energy levels at the Fermi surface of a metal allows for a ready exchange of energy between ionic and electronic subsystems. In molecular dynamics (MD) simulations of fast moving ions, the heat transfer to electrons is sometimes modelled as a frictional force that slows the ions. Quantum mechanical simulations lay bare these processes and reveal how best to charact...

The nonlinear system becomes an area with numerous investigations over the past decades. The conventional modal analysis could not be  applied on nonlinear continuous system which makes it impossible to construct the reduced order models and obtain system response based on limited number of measurement points. Nonlinear normal modes provide a useful tool for extending modal analysis to nonlinea...

In this paper we are interested in the dynamics and numerical treatment of a rolling disk on a flat support. The objective of the paper is to develop a numerical model which is able to simulate the dynamics of a rolling disk taking into account frictional resistance against sliding, pivoting and rolling. A mechanical model of a rolling disk is presented in the framework of Non-smooth Dynamics. ...

We measure the quality factor Q of electrically driven few-layer graphene drumhead resonators, providing an experimental demonstration that Q ∼ 1/T, where T is the temperature. We develop a model that includes intermodal coupling and tensioned graphene resonators. Because the resonators are atomically thin, out-of-plane fluctuations are large. As a result, Q is mainly determined by stochastic f...

In the present paper we study the propagation of pressure waves in a barotropic flow through a pipe, with a possibly varying cross-sectional area. The basic model is the SaintVenant system. We derive two multiscale models for the cases of weak and strong damping, respectively, which describe the time evolution of the piezometric head and the velocity. If the damping is weak, then the correspond...