The use of stiff cantilevers with diamond tips allows us to perform nanoindentations on hard covalent materials such as silicon with atomic force microscopy. Thanks to the high sensitivity in the force measurements together with the high resolution upon imaging the surface, we can study nanomechanical properties. At this scale, the surface deforms, following a simple non-Hertzian spring model. ...

We consider, in an open subset Ω of R , energies depending on the perimeter of a subset E ⊂ Ω (or some equivalent surface integral) and on a function u which is de ned only on E. We compute the lower semicontinuous envelope of such energies. This relaxation has to take into account the fact that in the limit, the holes Ω \ E may collapse into a discontinuity of u, whose surface will be counted ...

Objective- Postoperative pain management in patients that undergone arthroscopy is one of the most important procedures for their rehabilitation. Analgesic injection intra-articularly can facilitate pain control in such patients. The aim of this study was to evaluate the effects of ketamine on articular cartilage in rat model. Design- Experimental study. Animals- Twenty Wistar Rats Procedure...

This paper presents an asymptotically stabilizing discontinuous feedback controller for a class of nonholonoinic systems. The controller consists of two parts: the first part yields an invariant manifold on which all trajectories of the closed-loop system tend to the origin, and the latter part renders the invariant manifold attractive, while avoiding a discontinuity surface. The controller yie...

It is shown that two homogeneous elastic media of different rigidities adhering at a plane interface will become unstable at the surface of discontinuity when a certain critical magnitude of initial stress is attained. The general characteristic equation for the interfacial instability is derived for a general case of elastic anisotropy. The critical stress is evaluated as a function of the rig...

A quasi-static contact problem is considered for a non-linear elastic system with finitely many degrees of freedom. Coulomb’s law is used to model friction and the friction coefficient may be anisotropic and may vary along the surface of the rigid obstacle. Existence is established following a time-incremental minimization problem. Friction is artificially decreased to resolve the discontinuity...

We consider Filippov sliding motion on a co-dimension 2 discontinuity surface. We give conditions under which Σ is attractive through sliding which are sharper than those given in a previous paper of ours. Under these sharper conditions, we show that the sliding vector field considered in the same paper is still uniquely defined and varies smoothly in x ∈ Σ. A numerical example illustrate our r...

By investigating wave properties at cloak boundaries, invisibility cloaks with arbitrary shape constructed by general coordinate transformations are confirmed to be perfectly invisible to the external incident wave. The differences between line transformed cloaks and point transformed cloaks are discussed. The fields in the cloak medium are found analytically to be related to the fields in the ...

In this paper, we propose a robust motion estimation algorithm using uncalibrated 3D motion model considering depth discontinuity. Most of the previous direct motion estimation algorithms with 3D motion model compute the depth value through the local smoothing, which result in erroneous results at depth discontinuity. In this paper, we overcome this problem at depth discontinuity by adding disc...