When a small dynamical system that is initially in contact with a heat bath is detached from this heat bath and then caused to undergo a quasi-static adiabatic process, the resulting statistical distribution of the system's energy differs from that of an equilibrium ensemble. Subsequent contact of the system with another heat bath is inevitably irreversible, hence the entire process cannot be r...

We study the dislocation formation in 2D nanoscopic islands with two methods, the Molecular Static method and the Phase Field Crystal method. It is found that both methods indicate the same qualitative stages of the nucleation process. The dislocations nucleate at the film-substrate contact point and the energy decreases monotonously when the dislocations are farther away from the island-wettin...

The porosity of uniaxially compacted cohesive powders depends on the applied stress (including gravity). The case, where these stresses are weak, is considered. The compaction results in a porosity which is a function of sliding, rolling and torsion friction. By contact dynamics simulations it is shown that the influences of contact torques (static rolling and torsion friction) on the porosity ...

Introduction: Sick Building Syndrome (SBS) is a set of undesirable physical and psychological conditions whose symptoms appear when entering the building and disappear after leaving it. The most well-known symptoms of SBS include problems of nervous and respiratory systems and skin. Since nurses spend many hours in the hospital and enclosed spaces, they are exposed to many factors related to th...

This paper deals with the full discretization of quasistatic 3D Signorini problems with local Coulomb friction and a coefficient of friction which may depend on the solution. After a time discretization we obtain a system of static contact problems with Coulomb friction. Each of these problems is solved by the T-FETI domain decomposition method used in auxiliary contact problems with Tresca fri...

Finite element (FE) filtering facepiece respirators (FFRs) were developed and mated to the new headforms with a cervical spine model. The FFRs from three manufacturers included three sizing systems: (i) a single one-size-fits all, (ii) an FFR with two sizes (S/M and M/L), and (iii) an FFR with three sizes (S, L/M, XL). Finite element method (FEM) simulations of 16 headform and respirator combin...

We present an efficient scheme within the phase field framework for imposing dynamic contact angle boundary conditions for wall-bounded flows of two immiscible incompressible fluids with large density ratios. First, we develop an algorithm for imposing the dynamic contact angle boundary conditions to the Cahn–Hilliard equation. Our algorithm consists of two components: (i) we ignore the boundar...

The tribological properties of two smooth surfaces in the presence of a thin confined film are investigated with a generic model for the interaction between two surfaces and with computer simulations. It is shown that at large normal contact pressures, an ultra thin film automatically leads to static friction between two flat surfaces-even if the surfaces are incommensurate. Commen-surability i...

-We establish the equations of motion of an isothermal viscous Cahn-Hilliard fluid and we investigate the dynamics of fluids having moving contact lines under this theory. The force singularity arising in the classical model of capillarity is no longer present. This removal is due to a mass transfer across the interface combined with a finite thickness of the interface. A numerical simulation o...

We use an harmonic technique to probe the dynamics of a liquid-liquid interface in a capillary. The capillary pressure drop induced by a harmonic displacement of the fluids is recorded as a function of the excitation amplitude and frequency. At low frequency there is an amplitude threshold above which the contact line depins and slides, and this threshold is related to the static hysteresis of ...