The Impacts of Physical Exercise on Stress Coping and Well-Being in University Students in the Context of Leisure

This study aims at investigating the in-depth information regarding impacts of physical exercise on psychological well-being in university students with an emphasis on coping with stress in the context of leisure. A qualitative research, based on interview to draw findings in an inductive way, was conducted. Nine university students (N = 9) in a large mid-west university took part in a face- to face, semi-structured interviews using ten open-ended questions with respect to benefits of leisure time physical exercise. The interview on the basis of phenomenological research examined what the participants experienced with leisure time physical exercise in conjunction with stress coping and mental health. Meaningful units of themes were induced with 24 initially drawn themes. These themes were reduced to 8 comprehensive constituent themes: self-efficacy, positive emotion, mind and body, health-behaviors, self-esteem, leisure, problem-focused coping, and positive expectancy. These reduced themes were finally boiled down to 6 integrated themes: positive emotion, unity of mind and body, heightened self-esteem, leisure, problem-focused coping, and self-regulation of health behavior. This research may shed a light in illuminating potential mechanism of how regular physical exercise is conducive to enhanced health behavior as well as effective stress coping in university students in the context of leisure. In particular, this research appears to be meaningful in suggesting that regular leisure-time physical exercise can lead to an effective problem-focused coping through elicitation of positive emotion.

Reduction of chromium ore by recycled silicon cutting sludge waste with carbon addition

A basic study on the feasibility of producing ferrochrome (silicon) alloys using Si sludge waste collected from the silicon ingot cutting process was carried out, and the effects of the addition of carbon components, reaction time, and reaction temperature on the silicothermic reduction of chromium ore by Si sludge were studied. The cordierite (Mg2Al4Si5O18) phase was generated in the slag, and the Fe-Cr(-Si)-C alloy was formed by the silicothermic reduction. Moreover, the addition of carbon powder lowered the reduction initiating temperature, and the reduction ratio based on the oxygen content was evaluated at around 68-88% at 1573 K, which increased with an increase in carbon. However, it was difficult to find a significant difference in the reduction behavior in response to increasing the holding time. The reduced fer-rochrome (Fe-Cr) metal alloy droplets coalesced more intensively with an increase in reduction temperature, and for manufacturing the Fe-Cr alloy, it is estimated that a temperature of 1773 K or higher is required for good separation of the slag and the metal. Furthermore, the metallization ratio was defined, and higher values are evaluated for Fe than for Cr.

Synthesis and characterisation of potassium polytitanate for photocatalytic degradation of crystal violet

Potassium titanate nanostructures were synthesised by hydrothermal treatment of TiO2 （P25） in KOH and H2O2. As-produced powders were characterised by scanning electron microscopy, energy-dispersive X-ray spectroscopy, transmission electron microscopy, X-ray diffraction, and nitrogen adsorption-desorption methods. Longitudinally-oriented-wire-like structures with a length up to several micrometres and diameters ranging from 10 to 30 nm were obtained. Larger size fibrous nanowires resulting from the hydrotherrnal treatment showed high affinity in adsorbing crystal violet （CV）, which was mainly due to their high surface area. The photocatalytic bleaching of CV solution revealed that the wires are photoactive under ultraviolet light irradiation. Macroporous nanowires are considered as effective adsorbents of CV, capable of photocatalvtic degradation, and they can be easily separated from the solution by settling.