Size-affected dislocation-mediated plasticity is important in a wide range of materials and technologies. Here we develop a generalized size-dependent dislocation-based model that predicts strength as a function of crystal/grain size and the dislocation density. Three-dimensional (3D) discrete dislocation dynamics (DDD) simulations reveal the existence of a well-defined relationship between str...

We develop a mesoscopic dislocation dynamics model for vacancy-assisted dislocation climb by upscalings from a stochastic model on the atomistic scale. Our models incorporate microscopic mechanisms of (i) bulk diffusion of vacancies, (ii) vacancy exchange dynamics between bulk and dislocation core, (iii) vacancy pipe diffusion along the dislocation core, and (iv) vacancy attachment-detachment k...

  Background: Trans-scaphoid perilunate fracture-dislocation and perilunate dislocations are among uncommon injuries, most commonly seen in young patients due to high energy trauma. The treatment can be achieved either surgically by open reduc tion and internal fixation or closed reduction and casting.   Methods: To compare surgical versus non-operative results of treatment of trans-scaphoid pe...

Radiocarpal dislocation is an extremely uncommon injury in Traumatology, and is usually produced by high energy trauma. There are two types of dislocation, type I: pure radiocarpal dislocation and type II: fracture-dislocation. The gold standard treatment according to the literature is surgical treatment fixing the fractures and repairing the injured ligaments. We report a clinical case of radi...

We describe a model based in continuum mechanics that reduces the study of a significant class of problems of discrete dislocation dynamics to questions of the modern theory of continuum plasticity. As applications, we explore the questions of the existence of a Peierls stress in a continuum theory, dislocation annihilation, dislocation dissociation, finite-speed-of-propagation effects of elast...

Traumatic subconjunctival dislocation of the posterior chamber intraocular lens (PCIOL) is a rare and emergency condition. Here, we report an interesting variation of rare case of inferior subconjuctival dislocation of PCIOL in a 75-year-old female patient following blunt trauma to her right eye with cow's head. All the previous literature with subconjuctival dislocation of PCIOL has reported t...

The Peach-Koehler expression for the stress generated by a single (non-planar) curvilinear dislocation is evaluated to calculate the dislocation self stress. This is combined with a law of motion to give the self-induced motion of a general dislocation curve. A stability analysis of a rectilinear, uniformly translating dislocation is then performed. The dislocation is found to be susceptible to...

Dislocation model of strain anisotropy is presented. The dislocation theorem of strain broadening is suggested which means that strain broadening can only be caused by dislocation-type lattice defects. Based on this theorem strain anisotropy is modeled and accounted for by assuming that strain broadening is caused by dislocations or dislocation-type lattice defects. The effect of strain anisotr...

Fermi-level pinning by misfit dislocations at GaAs interfaces has been investigated. n -GaInAs was used to control the misfit dislocation density by varying of composition and epilayer thickness. interfaces with zero or low dislocation densities are Ohmic to current flow, and become rectifying with increasing dislocation density. The "Schottky barrier height" increases with dislocation density ...

Recurrent dislocation of the patella probably has several causes. In many patients abnormal laxity of the knee is present and this may predispose to dislocation (Dc Palma 1954). A family has come to our notice in which three members suffered recurrent dislocation of the patella and a fourth had probably sustained a single dislocation. All the former had abnormally lax knees and most other joint...