Considering that most of the falls in elderly population arise during walking, tests derived from walking performance would be desirable for comprehensive fall risk assessment. The analysis of spatial temporal parameters and the center of pressure displacement, which represents the interaction between the human body and the ground, would be beneficial. The aim of this study was to compare spati...

A linear piston hydraulic angular-velocity-based control knee joint was designed for people with knee-extensor weakness to engage knee-flexion resistance when knee-flexion angular velocity reaches a preset threshold, such as during a stumble, but to otherwise allow free knee motion. During mechanical testing at the lowest angular-velocity threshold, the device engaged within 2 degrees knee flex...

A novel composite architecture consisting of a periodic arrangement of closely-spaced spheres of a stiff material embedded in a soft matrix is proposed for extremely high damping and shock absorption capacity. Efficacy of this architecture is demonstrated by compression loading a composite, where multiple steel balls were stacked upon each other in a polydimethylsiloxane (PDMS) matrix, at a low...

Hypervelocity impact tests were carried out at 4.8 km/s using the Open University's All Axis Light Gas Gun (AALGG) in the Planetary and Space Sciences Research Institute (PSSRI)’s Hypervelocity Impact Laboratory. A first estimate of the peak loading pressures was made using preliminary hydrocode simulations, supported by calculations. Following a review of existing published quartz and sandston...

The study put forth demonstrates that the seed electrons average kinetic energy influences the discharge characteristics making it possible to maximize the rate of development of the virtual anode in a pseudospark, with a suitable choice of the neutral gas pressure as determined by the seed’s average injection speed. This investigation also brings to light two distinct operating regimes; (1) mi...

most impact tests are carried out on specimens with specific stacking sequence and dimensions to meet standard and experimental limitations. the damaged areas and the resulted reduction in the strength values of specimens may not agree very well with those of real application. in this paper an attempt is made to study the variation in the size of damaged areas due to varying the dimension of te...