OBJECTIVES To establish a laboratory model of implant cutout, which can evaluate the effect of implant design on cutout resistance in a clinically realistic "worst case" scenario. SETTING Orthopaedic biomechanics laboratory. DESIGN Implant cutout was simulated in an unstable pertrochanteric fracture model, which accounted for dynamic loading, osteoporotic bone, and a defined implant offset....

safety and failure in gas pipelines are very important in gas and petroleum industry. for this reason, it is important to study the effect of different parameters in order to reach the maximum safety in design and application. in this paper, a three dimensional finite element analysis is carried out to study the effect of crack length, crack depth, crack position, internal pressure and pipe thi...

C-B spline can not represent semi-circle and semi-elliptical arcs precisely. This paper will discuss the nature of C-B spline’s and C-Bézier curve’s endpoints. Then, on the basis of the analysis of their characteristics and by means of adding control points to make C-B spline dominate the first and last vertices of the polygon and get tangency with the first and end sides. Thus it has given out...

The luminosity dependence of kinematical and isophotal properties of elliptical galaxies is investigated using numerical simulations of galaxy merging, combined with semi-analytical models of hierarchical structure formation. Mergers of spiral galaxies as the only formation mechanism for elliptical galaxies can neither reproduce the kinematical and photometric properties of very massive ellipti...

Background: Semi-recumbent cycling exercise has been used as a strategy to complement gait retraining in individuals with disordered walking ability. However, seated elliptical stepping might be a more potent exercise modality for this purpose. Yet, there has not been a kinematic analysis of elliptical stepping exercise, whereby the movement path is produced by a slider-crank mechanism. This st...