Descriptor systems with inequality (unilateral) constraints may have singularities (impasse points) if the set of active constraints changes in the time interval of interest. A typical example are contact conditions in constrained mechanical systems that can be formulated as unilateral constraints for the position and velocity coordinates. We discuss these singularities in detail for a simple m...

background: poor hygiene will provide good condition for corneal infections by opportunistic free-living amoebae (fla) in soft contact lens wearers. in the present study an amoebic keratitis due to hartmannella has been recognized in a 22-year-old girl with a history of improper soft contact lens use. she had unilateral keratitis on her left eye. her clinical signs were eye pain, redness, blurr...

We start with a three-dimensional equilibrium problem involving a linearly elastic solid at small strains subjected to unilateral contact conditions. The reference configuration of the solid is assumed to be a thin shallow shell with a uniform thickness. We focus on the limit when the thickness tends to zero, i.e. when the three-dimensional domain tends to a two-dimensional one. In the generic ...

This paper represents a continuation of [1] and [2]. Here, we consider the numerical analysis non-trivial frictional contact problem in form system evolution nonlinear partial differential equations. The model describes equilibrium viscoelastic body sliding with moving foundation. is modeled multivalued normal compliance condition memory term restricted by unilateral constraint associated versi...