A nonlinear two degree-of-freedom model, describing a flexible elastic suspended cable undergoing galloping oscillations, is analyzed. By using a perturbative approach, the critical conditions occuring for different values of the aerodynamic coefficients are described. Two different type of critical conditions, corresponding to simple or double Hopf bifurcations are found. The nonlinear postcri...

Certain nanoparticles exhibit intense light emission during their elastic deformation, called the phenomenon of elastico mechanoluminescence (EML).When ZnS:Mn and SrAl2O4:Eu nanoparticles are deformed in the elastic region by the stress initially increasing with time and then attaining a fixed value or by the stress initially increasing and then decreasing with time or by the impact stress, the...

Damage to fault-zone rocks during fault slip results in the formation of a channel of low seismic-wave velocities. Within such channels guided seismic waves, denoted by Fg, can propagate. Here we show with core samples, well logs and Fg-waves that such a channel is crossed by the SAFOD (San Andreas Fault Observatory at Depth) borehole at a depth of 2.7 km near Parkfield, California, USA. This l...