A striking geometric property of elastic bodies with dislocations is their non-Riemannian nature in the sense that the deformation tensor cannot be written as the gradient of a one-to-one immersion, since its curl must not be zero, but equals to the density of dislocations, a concentrated Radon measure in the dislocation lines. In this work, we discuss the mathematical properties of such constr...

We use in situ transmission electron microscopy to directly observe, at high temporal and spatial resolution, the interaction of ferroelectric domains and dislocation networks within BiFeO3 thin films. The experimental observations are compared with a phase field model constructed to simulate the dynamics of domains in the presence of dislocations and their resulting strain fields. We demonstra...

Based on an orientation-dependent dislocation line energy, a solution to the acoustic nonlinearity parameter is obtained for pure and mixed dislocations in anisotropic crystals. The solution is validated by comparison with molecular dynamic simulations. Parametric studies using this new solution show that (i) elastic anisotropy can significantly change the nonlinear behavior of dislocations inc...

Introduction: Elbow dislocations are uncommon in children. The treatment and outcomes remains controversial. MATERIALS AND METHODS We report retrospectively the clinical and functional results of elbow dislocations in children treated in Sahloul University Hospital. Both isolated or pure dislocations and those associated with other injuries were evaluated separately. Results: Forty-eight chil...

Work hardening in crystalline materials is related to the accumulation of statistically stored dislocations in low-energy structures. We present here a model which includes dislocation dynamics in the rate-independent setting for plasticity. Three basic physical features are taken into account: (i) the role of dislocation densities in hardening; (ii) the relations between the slip velocities an...

We study the relaxation dynamics of systems of straight, parallel crystal dislocations, starting from initially random and uncorrelated positions of the individual dislocations. A scaling model of the relaxation process is constructed by considering the gradual extinction of the initial density fluctuations present in the system. The model is validated by ensemble simulations of the discrete dy...

This paper provides evidence on the benefits of faster proprietary data feeds from stock exchanges over the regulated “public” consolidated data feeds. We measure and compare the National Best Bid and Offer (NBBO) prices in each data feed at the same data center. Price dislocations between the NBBOs occur several times a second in very active stocks and typically last one to two milliseconds. T...

THE PATIENT A 37-year-old man injured his right wrist in a motor vehicle collision. In the emergency department he had severe wrist pain and median nerve paresthesia. Wrist radiographs identified a dorsal perilunate dislocation (PLD) with the carpus dislocated dorsally and the lunate tilted volar but still located in the lunate fossa. Post-reduction computed tomography scan confirmed no fractures.

Dislocations are extended defects within crystalline solids that often influence the mechanical, electrical, magnetic and optical properties of the material. Establishing more quantitative relationships between dislocations and material properties relies on effective microscopy or spectroscopy methods that can resolve both dislocation type and position within the solid. Diffraction has historic...