In this paper we present the equations of motion of a moving screw dislocation in the framework of the translation gauge theory of dislocations. In the gauge field theoretical formulation, a dislocation is a massive gauge field. We calculate the gauge field theoretical solutions of a uniformly moving screw dislocation. We give the subsonic and supersonic solutions. Thus, supersonic dislocations...

We demonstrate that strained GeSi/Si heterostructures act as a model system for the study of the interaction of propagating dislocations with point, line and planar defects. In such heterostructures, the effective stress acting on a propagating dislocation may be varied from tens of MPa to of order 1 GPa, and the length of the propagating dislocation segment may be varied from nm to hundreds of...

Knee dislocations are devastating when they occur on the athletic field or secondary to motor sports. The complexity of presentation and spectrum of treatment options makes these injuries unique and extremely challenging to even the most experienced knee surgeons. An astute appreciation of the treatment algorithm is essential to plan individualized management since no two complex knee dislocati...

BACKGROUND The purpose of this study was to determine the annual incidence rates of non-work-related traumatic fractures and dislocations (excluding head and facial injuries) referred for orthopaedic services in a large population enrolled under a capitated insurance contract. METHODS The number of fractures and dislocations that were referred for orthopaedic services were recorded prospectiv...

Device quality wurtzite-GaN (a) can be grown using metalorganic chemical vapor phase deposition (MOCVD) on (0001) sapphire substrates. The large lattice misfit results in dislocation tangles near the interface but isolated threading dislocations, parallel to c, with densities ,109 cm22 and Burgers vectors c, a, and c 1 a persist beyond ,0.5 mm above the interface [1–3] and thus cross the active...

The pathomechanics, ligamentous damage, and degree of carpal instability in perilunate and lunate dislocations were analyzed by experimentally loading 32 cadaver wrists to failure. Thirteen perilunate and two lunate dislocations were produced. The mechanism of injury was extension, ulnar deviation, and intercarpal supination. These dislocations occurred in a sequential fashion due to progressiv...

The phase-field approach to dislocations is conceptually advanced. Large strain formulation is developed. A local thermodynamic potential eliminates stress dependence of the Burgers vector and reproduces the desired local stress-strain curve, as well as the desired, mesh-independent, dislocation height for any dislocation orientation. A gradient energy contains an additional term, which exclude...

Bilateral asymmetric dislocations of the hip are rare compared to unilateral dislocations. This case study describes a female restrained passenger involved in a motor vehicle accident who sustained asymmetric bilateral hip dislocations. The patient underwent successful closed reduction of both hips. The clinical course and follow-up assessment of the patient was otherwise uneventful. Computed t...

INTRODUCTION Injuries of the hip joint from pure hip dislocations to fracture dislocations have been described and classified by various authors. These descriptions do not include fracture dislocation of hip associated with fracture of the greater trochanter. CASE REPORT We report an unusual case of fracture dislocation of hip in which posterior dislocation of hip was associated with fracture...