Reflection and the art of coaching: fostering high-performance in olympic ski cross

In preparation for the 2010 Vancouver Winter Olympic Games, the lead author engaged in systematic reflection in an attempt to implement coaching behaviours and create practice environments that promoted athlete development (psycho-social and physical performance). The research was carried out in relation to his work as head Ski Cross coach working with (primarily) three athletes in their quest for Olympic qualification and subsequent performance success in the Olympic Games. This project sought to examine coach-athlete interactions. Of particular interest were coach and athlete responses regarding the implementation of autonomy supportive coaching behaviours in a high context. Autonomy supportive coaching behaviours have previously been strongly associated with positive athlete psycho-social and performance outcomes, however, a paucity of research has examined its implementation in high-performance contexts. Through the use of participant ethnography, it was possible to gain considerable insights regarding athletes' perceptions of choice, implications of perceived athletic hierarchies, as well as cultural and experience-related influences on training and performance expectations

Effect of Austempering on Plastic Behavior of Some Austempered Ductile Iron Alloys

A numerical description relating microstructure to elastic and plastic deformation behavior would make it possible to simulate the mechanical behavior of complex cast components with tailored material properties. Limited work and data have however been published regarding the connection between microstructure and plastic behavior of austempered ductile irons (ADI). In the current work the effects of austempering temperature and austempering time on the strength coefficient and the strain hardening exponent of the Hollomon equation have been investigated for two ADI alloys. The results show that the plastic behavior is highly dependent on the combination of austempering temperature and austempering time. It was found that as the austempering temperature increases both the strength coefficient and the strain hardening exponent initially decrease, but after reaching a minimum at the critical austempering temperature they show a plateau or an increase. The effect of the austempering time on the plastic behavior depends on the austempering temperature. At low austempering temperatures the strength coefficient and the strain hardening exponent decrease with increased austempering time, whereas at higher austempering temperatures they show little time dependence. These relations are explained by the microstructural transformations that take place during the austempering heat treatment