LiNbO3 is a ferroelectric material with a rhombohedral R3c structure at room temperature. A LiNbO3 bicrystal with a f1210g=h1010i 1 low-angle tilt grain boundary was successfully fabricated by diffusion bonding. The resultant boundary was then investigated using highresolution TEM. The boundary composed a periodic array of dislocations with b 1⁄4 1=3h1210i. They dissociated into two partial dis...

T he glenohumeral joint is the most mobile and one of the most frequently dislocated joints in the human body. Before skeletal maturity, shoulder dislocations are less frequent, and shoulder trauma more often results in fracture through the proximal humeral physis. In a recent epidemiologic study, Zacchilli and Owens found that shoulder dislocations follow a bimodal distribution, with 46.8% occ...

A Modified Iris Suture Technique for In-the-bag Intraocular Lens Dislocation Clinically significant posterior chamber intraocular lens (PCIOL) decentrations or dislocations occur in the aftermath of approximately 2% to 3% of cataract surgeries. Early inor out-of-the-bag intraocular lens (IOL) dislocations arise within 3 months of surgery, primarily as a result of traumatic zonular or capsular r...

– We present experimental results on resonant spin tunnelling in a single crystal of Mn12-2Cl benzoate with different concentration of dislocations. The time evolution of the magnetisation follows the stretched exponential, M (t) ∝ exp[−(t/τ) β ] over a few time decades. The values of τ and β deduced from experiment have been used to determine the concentration of dislocations before and after ...

ÐThe interaction between dislocations and semicoherent precipitates (O phase) is discussed. The investigation shows that the semicoherent precipitate is cut by dislocations during deformation. Conventional TEM and HRTEM observations demonstrate that shearing of precipitates by dislocations occurs by multiple cutting of the precipitate. A strengthening mechanism is proposed based on this observa...

Patellofemoral (PF) dislocations are frequently associated with chondral injury. Chondral and osteochondral lesions are often associated with traumatic (high-energy) PF dislocations, whereas atraumatic (low-energy) PF dislocations in patients with significant PF risk factors have a much lower incidence of osteochondral damage. This article provides a historical overview and delineates the curre...

Monteggia fractures are rare in children, and subtle radial head dislocations, with minor plastic deformation of the ulna, may be missed in up to a third of cases. Complications of Monteggia fractures-dislocations include persistent radial head dislocation, forearm deformity, elbow stiffness, and nerve palsies at the time of presentation. An unusual case of median nerve palsy following elastic ...

In this paper, we deduce a macroscopic strain gradient theory for plasticity from a model of discrete dislocations. We restrict our analysis to the case of a cylindrical symmetry for the crystal in exam, so that the mathematical formulation will involve a two dimensional variational problem. The dislocations are introduced as point topological defects of the strain fields, for which we compute ...

Crystalline materials deform in an intermittent way via dislocation-slip avalanches. Below a critical stress, the dislocations are jammed within their glide plane due to long-range elastic interactions and the material exhibits plastic response, while above this critical stress the dislocations are mobile (the unjammed phase) and the material flows. We use dislocation dynamics and scaling argum...

The DLTS (Deep Level Transient Spectroscopy) and PL (Photoluminescence) spectra of dislocations introduced in Cz-Si (single crystal grown by the Czochralski method) under clean conditions have been studied. The oxygen effect on the formation of both spectra has been revealed. For the first time, a concomitant decay of both PL and DLTS signals with deformation duration in the range of 0.25 to 14...