Dimensions of Athlete-Coach Relationship and Sport Anxiety as Predictors of the Changes in Psychomotor and Motivational Welfare of Child Athletes after the Implementation of the Psychological Workshops for Coaches.

(1) Background: Coach workshops based on seven principles (inspiration, explanation, expectation, support, reward, appreciation, growth, and winning) enhance the sport experience of adult athletes. Here, we report effects of such workshops with coaches of child athletes and the predictors of those changes. (2) Methods: Study participants were 8 coaches of 57 children aged between 9 and 12 years old (girls practicing gymnastics and boys practicing football). Three coaches of 28 children attended three workshops over 12 weeks, while a control group of 5 coaches of 29 children attended no workshops. Measures of motivation, relationships, anxiety, and psychomotor performance were taken on children before and after the intervention. (3) Results: There were significant effects of the workshop on motivation and psychomotor performance. The analysis of the predictors the intervention used in this study might be effective for enhancing psychomotor performance and motivation while considering components of Athlete-Coach relationship and anxiety levels as moderators. (4) Conclusions: The beneficial effects of the workshop are encouraging but need to be investigated with higher numbers of coaches and children from various sport disciplines.

Damage Development on the Surface of Nickel Coating in the Initial Period of Erosion.

The common occurrence of the phenomenon of cavitation in many industries and the multitude of factors affecting the resistance to cavitation erosion of used materials contribute to the search for methods and appropriate parameters of coating application that are able to minimize the effects of erosion. To determine the validity of the developed application parameters and the method used, cavitation studies and microscopic observations of the development of erosion during the cavitation test were carried out. There was a clear lack of incubation time and a linear increase in losses after 60 min of the test. Moreover, the damage observed during the test overlapped, widening the area of erosion and thus leading to damage to the integrity of the coating.

Effect of Thermal Treatment and Erosion Aggressiveness on Resistance of S235JR Steel to Cavitation and Slurry.

S235JR steel is used in many applications, but its resistance to the erosion processes has been poorly studied. To investigate this resistance, cavitation, and slurry erosion tests were conducted. These tests were carried out at different erosion intensities, i.e., different flow rates in the cavitation tunnel with a system of barricades and different rotational speeds in the slurry pot. The steel was tested as-received and after thermal treatment at 930 °C, which lowered the hardness of the steel. To better understand the degradation processes, in addition to mass loss measurements, surface roughness and hardness were measured. Along with increasing erosion intensity, the mass loss increased as well. However, the nature of the increase in mass loss, as well as the effect of steel hardness on this mass loss, was different for each of the erosion processes. In the cavitation erosion tests, the mass loss increased linearly with the increase in flow velocity, while in the slurry tests this relationship was polynomial, indicating a strong increase in mass losses with an increase in rotational speed. Cavitation erosion resulted in stronger and deeper strain hardening than slurry. Surface damage from cavitation erosion tests was mainly deep pits, voids, and cracks during the slurry tests, while flaking was the most significant damage.