PURPOSES To examine radiographically the component motion in a bipolar prosthesis and to determine whether the self-centering mechanism really works in vivo. METHODS 38 patients with 41 bipolar hip endoprostheses (30 for coxarthrosis and 11 for osteonecrosis of femoral head) were included in this study. Two radiographs of each case were taken to evaluate the self-centering mechanism. The firs...

We show a computationally efficient approximation (cf. [1]) of a full analogy model [2, 3], implemented in a computer program, and tested on the CoNLL2000 chunk tagging task [4], putting clause boundaries around mainly np and vp phrases. Our implementation showed to be competitive with other memory based learners. It deviates only slightly from the theoretical model. First, it implements a vers...

Abstract Post-tensioned precast concrete walls are an attractive research trend in structural engineering, which replaces cast-in-place earthquake-prone buildings. Precast use mild steel and high-strength post-tensioning for flexural resistance. Mild reinforcement yields tension compression, dissipating inelastic energy. Unbounded tendons used inside the wall to give self-centering capability, ...

The degradation of reinforced concrete (RC) structural components owing to aging mechanisms and extreme loading events can cause significant performance safety concerns. Among the available alternatives for restoring such components, shape memory alloys (SMAs) exhibit unique properties, including recovery inelastic strain upon unloading (superelasticity) and/or heating (shape effect, SME). Part...

In order to improve the resilience of structures subjected strong earthquakes, a buckling-plate self-centering friction damper (BPSCFD) with low post-yielding stiffness is proposed, which consists group post-buckling plates and variable mechanism. The intended not only reduce peak residual deformation structures, but also limit additional internal force structural elements. Through theoretical ...

introduction: transportation is an important iatrogenic endodontic error which might cause failure. this study evaluated the canal transportation caused by neoniti and protaper instruments, using cone-beam computed tomography (cbct) cross sections. methods and materials: this in vitro experimental study was performed on 40 mesiobuccal roots of maxillary first molars. the teeth were scanned with...