We consider an exact reduction of a model of Field Dislocation Mechanics to a scalar problem in one spatial dimension and investigate the existence of static and slow, rigidly moving single or collections of planar screw dislocation walls in this setting. Two classes of drag coefficient functions are considered, namely those with linear growth near the origin and those with constant or more gen...

BACKGROUND AND PURPOSE Long-term outcome after surgery for grade-V acromioclavicular joint dislocation has not been reported. We performed a retrospective analysis of functional and radiographic outcome 15-22 years after surgery. PATIENTS AND METHODS We examined 50 patients who were treated at our hospital between April 1985 and December 1993. Various methods of stabilization were used: K-wir...

We develop a geometry-based model from first-principles data for the interaction of solutes with a prismatic screw dislocation core, and predict the thermally activated cross-slip stress above room temperature in Mg alloys. Electronic structure methods provide data for the change in prismatic stacking fault energy for different possible fault configurations for 29 different solutes. The direct ...

Computer simulation of the core structure and glide of ordinary 1/2<110] dislocations and <101] superdislocations in L10 TiAl has been performed using the recently constructed Bond-Order Potentials. This description of atomic interactions includes explicitly, within the tightbinding approximation, the most important aspects of the directional bonding, namely d-d, p-p and d-p bonds. The ordinary...

Using QM-Sutton-Chen many-body potential, we have studied the 1/2a〈1 1 0〉 screw dislocation in nickel (Ni) via molecular dynamics (MD) simulations. We have studied core energy and structure using a quadrupolar dislocation system with 3D periodic boundary conditions. The relaxed structures show dissociation into two partials on {1 1 1} planes. The equilibrium separation distance between the two ...

Objective: The morbidity and mortality are high for traumatic upper cervical spine instability with cervico-medullary compression. In a clinical retrospective study, the clinical and radiographic results of occipitocervical (OC) fusion using posterior atlantoaxial transpedicular screw fixation in 12 patients with traumatic upper cervical spine instability was reviewed. Methods: Twelve patients ...

BACKGROUND Fracture-dislocation of the proximal interphalangeal (PIP) joint is a relatively common injury. Various treatments for fracture-dislocation of the PIP joint have been reported. In the present study, we performed open reduction through a midlateral incision using absorbable sutures to reduce the small bone fragments and performed volar plate repair. METHODS We treated nine patients ...

Dislocation internal friction observations in iron are reported with "in situ" hydrogen charging to study its influence on the kink pair formation in screw dislocations (Y peak) and its possible relation to earlier observed softening effects. Also some substructures in the hydrogen cold-work peak are revealed.

In this work, it is shown that a non-zero vacuum energy density (the Casimir energy) for a scalar field appears in a continuous elastic solid due to the presence of a topological defect, the screw dislocation. An exact expression is obtained for this energy density in terms of the Burgers vector describing the defect, for zero and finite temperature.

From our daily life we are familiar with hexagonal ice, but at very low temperature ice can exist in a different structure--that of cubic ice. Seeking to unravel the enigmatic relationship between these two low-pressure phases, we examined their formation on a Pt(111) substrate at low temperatures with scanning tunneling microscopy and atomic force microscopy. After completion of the one-molecu...