We analyze the processes of thermal softening, melting and subsequent melt lubrication that occur during the high speed sliding of a metal piece on another metal block. The temperature rise in the slider arising from both high speed interface friction and from the energy dissipated during plastic deformations is computed using simple analysis and the finite element method. Subsequently, we prop...

Natural contacting surfaces have remarkable surface mechanical properties, which has led to the development of bioinspired surface structures using rubbery materials with strongly enhanced adhesion and static friction. However, sliding friction of structured rubbery surfaces is almost always significantly lower than that of a flat control, often due to significant loss of contact. Here we show ...

Self-heating effects and temperature rise in AlGaN/GaN HEMTs grown on silicon and sapphire substrates are studied, exploiting transistor dc characterization methods. A negative differential output resistance is observed for high dissipated power levels. An analytical formula for a source-drain current drop as a function of parasitic source resistance and threshold voltage changes is proposed to...

We have performed a systematic, large-scale simulation study of granular media in two and three dimensions, investigating the rheology of cohesionless granular particles in inclined plane geometries, i.e., chute flows. We find that over a wide range of parameter space of interaction coefficients and inclination angles, a steady-state flow regime exists in which the energy input from gravity bal...

The results obtained in this study show that as the dart leader tip passes a given point on the defunct return stroke channel the electric field increases within a fraction of a microsecond to values larger than the critical electric field necessary for the initiation of cold electron runaway in low-density air comprising the channel. These results are in support of the hypothesis that cold run...

In order to properly model the friction and wear of elastomer materials, it is essential to understand some specific mechanical and tribological features. Mechanical characteristics of elastomer materials are different from those of metals and other relatively hard materials. Elastomers can bear large deformations, the stress-strain curves are non-linear, time and temperature dependent. When th...