Piotr Kowalczyk

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Implant separation from bone tissue, resulting in the necessity for revision surgery, is a serious drawback of cementless total joint replacement. Unnatural stress distribution around the implant is considered the main reason for the failure. Optimization of the implant properties, especially its geometric parameters, is believed to be the right way to(More)
OBJECTIVE The aim of the paper is to analyse an influence of the shape of the layers in photo-cured dental restorations of Class I on distribution of shrinkage stresses along the tooth-restoration interface. The study is a continuation of the previous considerations (Kowalczyk and Gambin (2008) [1]), where techniques, which reduce stress concentration at(More)
Evaluation of constitutive properties of cancellous bone and their relationships to microstructural parameters is a crucial issue in analysis of stresses and strains in bone tissues and simulation of their remodelling. Known limitations of experimental methods as well as of the micro-FE techniques make the analysis and homogenization of 'equivalent'(More)
We are interested in understanding the mechanisms behind and the character of the sway motion of healthy human subjects during quiet standing. We assume that a human body can be modelled as a single-link inverted pendulum, and the balance is achieved using linear feedback control. Using these assumptions, we derive a switched model which we then(More)
Glucocorticoids (GCs) are well-known anti-inflammatory compounds, but they also inhibit cell proliferation depending on cell type. Similarly, peroxisome proliferator-activated receptors (PPARα, PPARδ, and PPARγ) also possess anti-proliferation properties beyond their canonical roles as metabolic mediators. In the present study, we investigated the potential(More)
This paper investigates border-collision bifurcations in piecewise-linear planar maps that are non-invertible in one region. Maps of this type arise as normal forms for grazing–sliding bifurcations in three-dimensional Filippovtype systems. A possible strategy is presented for classifying fixed and period-2 points, that are involved in such bifurcations.(More)