The dislocation distribution of high-quality single-crystal gallium nitride (GaN) films grown by the hybrid vapor phase epitaxy was analyzed. This study examined the domain structure of GaN from the dislocation distribution on the macroscale by optical microscopy. The surface structure of GaN consisted of domains with microcolumns as the substructure. The inner domains contained a lower density...

Waves that have an isotropic intensity distribution about the propagation axis may carry well-defined, quantized orbital angular momentum. The angular momentum is nonzero in the presence of screw dislocations. It is shown that these dislocations can be represented by a complete orthogonal set of functions (such as the Gauss–Laguerre set, which is valid for the paraxial approximation). Represent...

 Abstract  Background: Chronic neglected dislocation of the shoulder joint can be defined  as a neglected dislocation for more than a 3 week period. However, it has been shown that the negligence could range from a 24 hour period to 6 months1. Depending on age, signs, symptoms, etiology and types of dislocation, conservative treatment or surgical intervention could be considered.  Methods: In t...

  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...

introduction sub axial cervical spine dislocations are common and managing these cases by closed reduction is successful in the majority of cases. however, treatment of old and neglected cases is difficult and the results may vary in terms of neurological and functional outcomes. case presentation we present two cases of traumatic bilateral cervical facet dislocation with no neurological defici...

The frequency dependence00 to 200 M H Z ~ O ~ the sound velocity and of the ultrasonic attenuation a has been measured on high purity Cu during 3 MeV y-irradiation at room temperature. The results are evaluated with respect to dislocation effects which under the present conditions cause the major contributions to the frequency dependent reduction of sound velocity AvD!v0 and attenuation aD. The...