We present an application of the discrete dislocation theory to the characterization of the energetics of kinks in Mo, Ta and W body-centered cubic (BCC) crystals. The discrete dislocation calculations supply detailed predictions of formation and interaction energies for various double-kink formation and spreading mechanisms as a function of the geometry of the double kinks, including: the depe...

Aalto University, P.O. Box 11000, FI-00076 Aalto www.aalto.fi Author Sakari Sintonen Name of the doctoral dissertation Synchrotron radiation x-ray topography of crystallographic defects in GaN Publisher School of Electrical Engineering Unit Department of Microand Nanosciences Series Aalto University publication series DOCTORAL DISSERTATIONS 187/2014 Field of research Nanotechnology Manuscript s...

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...

BACKGROUND The acromioclavicular (AC) joint dislocation is a major reason for shoulder instability. Different concepts of treatment and surgical methods are described in the literature. Thus, the purpose of this study was to present our data of long-term follow-up of patients having undergone treatment of acromioclavicular (AC) joint dislocation using the Bosworth Screw with additional K-wiring...

The strain field of isolated screw and edge dislocation cores in aluminum are calculated using density-functional theory and a flexible boundary condition method. Nye tensor density contours and differential displacement fields are used to accurately bound Shockley partial separation distances. Our results of 5-7.5 A (screw) and 7.0-9.5 A (edge) eliminate uncertainties resulting from the wide r...

Discrete dislocation dynamics (DD) simulations in conjunction with stereo and in situ straining transmission electronic microscopy (TEM) were used to study dislocation motion in thin Cu foils. Stereo imaging prior to and following in situ tensile straining is utilized to describe the three-dimensional (3D) evolution of dislocation structures with incremental straining and observation by TEM. Th...

Here we report the first direct atomic scale experimental observations of oxygen segregation to screw dislocations in GaN using correlated techniques in the scanning transmission electron microscope. The amount of oxygen present in each of the three distinct types of screw dislocation core is found to depend on the evolution and structure of the core, and thus gives rise to a varying concentrat...

The paper addresses the problem of correlation within an array of parallel dislocations in a crystalline solid. The first two of a hierarchy of equations for the multi-point distribution functions are derived by treating the random dislocation distributions and the corresponding stress fields in an ensemble average framework. Asymptotic reasoning, applicable when dislocations are separated by s...

conclusions bosworth screw and tension band wiring are both useful procedures in patients with acj dislocation, but each should be used in the selected patients with special indications. both methods had good results during follow-up period. there was not statistically meaningful difference in the articular stability, range of motion, oss score and vast score between the two groups (p > 0.05). ...

Molecular dynamics (MD) and experiments indicate that the high-speed dislocations dominate plasticity properties of crystal materials under high strain rate. New physical features arise accompanied with increase in dislocation speed, such as “Lorentz contraction” effect moving screw dislocation, anomalous nucleation, annihilation interaction. The static description is no longer applicable. elas...