We discuss an atomistic model for heterogeneous nanowires, allowing for dislocations at the interface. We study the limit as the atomic distance converges to zero, considering simultaneously a dimension reduction and the passage from discrete to continuum. Employing the notion of Gamma-convergence, we establish the minimal energies associated to defect-free configurations and configurations wit...

/department of mechanical engineering Introduction In plastic deformations, which arise due to the motion of dislocations in crystalline microstructure, size effects cannot be neglected at a small scales of observation. Within each grain of a polycrystal, the grain boundaries act as natural obstacles to dislocation motion. Due to the stresses dislocations exert onto each other, dislocations wil...

We present the case of a professional horse jockey with chronic, bilateral, posterior sternoclavicular dislocations. Traumatic dislocation of the sternoclavicular is a relatively rare but potentially devastating injury. Posterior sternoclavicular dislocations occur less frequently than anterior dislocations and require careful and complete evaluation because of the potential for serious complic...

BACKGROUND Proximal interphalangeal joint (PIPJ) dislocations represent a significant proportion of hand clinic visits and typically require frequent follow-ups for clinical assessment, orthotic adjustments, and physiotherapy. There are a large number of treatment options available for PIPJ dislocations, yet no prospective or controlled studies have been carried out, largely due to the diversit...

INTRODUCTION Majority of bilateral shoulder dislocations are posterior. Simultaneous bilateral anterior shoulder dislocations and bilateral anterior fracture-dislocations are rare and mostly of traumatic origin. We present a rare case of bilateral anterior shoulder dislocation with symmetrical greater tuberosity fracture following an episode of seizure with an unusual injury mechanism which was...

Scanning Kelvin probe microscopy ~SKPM! and conductive atomic force microscopy ~C-AFM! have been used to image surfaces of GaN grown by molecular beam epitaxy. Detailed analysis of the same area using both techniques allowed imaging and comparison of both surface potential variations arising from the presence of negatively charged threading dislocations and localized current leakage paths assoc...

Considering recently computed formation and migration energies of kinks on non-dissociated dislocations, we have compared the relative mobilities of glide partial and shuffle perfect dislocations in silicon. We found that the latter should be more mobile over all the available stress range, invalidating the model of a stress driven transition between shuffle and glide dislocations. We discuss s...

Bilateral knee dislocations seldom occur, and fewer than a dozen cases of bilateral luxatio erecta humeri (erect dislocation of the shoulder) have been reported. Here we present the case of a patient who sustained bilateral knee dislocations and bilateral luxatio erecta humeri in a motorcycle accident. Transient neurologic compromise resolved with closed reduction of the bilateral shoulder and ...

The stability to dislocations of the elastic phase, or “Bragg glass,” of a randomly pinned elastic medium in two dimensions is studied using the minimum-cost-flow algorithm for a disordered fully packed loop model. The elastic phase is found to be unstable to dislocations due to the quenched disorder. The energetics of dislocations are discussed within the framework of renormalization group pre...

We put forward properties of solitons supported by optical lattices featuring topological dislocations and show that solitons experience attractive and repulsive forces around the dislocations. Suitable arrangements of dislocations are even found to form soliton traps, and the properties of such solitons are shown to crucially depend on the trap topology. The uncovered phenomenon opens a new co...