Grzegorz Kmita

Design considerations related to noise pollution have become extremely important recently in many industries. Despite the wide range of applications and various noise spectrum the methodology remains quite common. The power products operating in the power systems are very often affected by a noise emission side effect and must be carefully designed with respect to the resulting noise emission and its influence on the surrounding environment consequently. Noise management, design concept examples as well as the modern techniques for noise sources characterization in transformers are presented in this paper.

The “strain-life time” method has been adapted for life-time prediction of polymer and composite bone joint screws. Mechanical and fatigue properties of screws made of biostable (polysulfone), biosorbable (poly(lactide-co-glycolide) and short carbon fibre reinforced polymer composite materials have been examined in this study. The lifetime predictions under in vitro conditions were calculated for polymer and composite implants. The forecasting of joint screws stability under conditions close to natural body environment is shown to be feasible based on equations describing lifetime of the examined joint screws.