Eurotech (Poland)

BACKGROUND: The aim of this study was to assess spinal mobility in elite table tennis players compared to non-athletes.METHODS: The research was conducted on a group of 20 table tennis players from Polish Ekstraklasa league clubs (study group). The control group consisted of 20 students, who did not practice any sport. Cervical, thoracic and lumbar spine mobility in the sagittal and transverse planes was measured using a Saunders inclinometer (Saunders Group Ltd, Tbilisi, Georgia). The author’s questionnaire was also used to examine whether physical activity can have an effect on the prevalence of spinal pain, and body position and region in which the pain occurs.RESULTS: Statistically significant differences between the groups were observed in flexion and extension of the intervertebral disc space between the spinous processes of the twelfth thoracic vertebra and the first lumbar vertebra and extension of the intervertebral disc space between the spinous processes of the seventh cervical vertebra and the first thoracic vertebra and the midpoint of the sacral bone.CONCLUSIONS: The study group of young table tennis players of the Polish Ekstraklasa League had better ranges of motion in the cervical, thoracic and lumbar spine in the sagittal and transverse planes compared to their non-athlete peers. Further research is needed to determine whether table tennis can alter spinal mobility in other spinal segments and planes of motion.

Air quality is an important factor for human well-being, and it is crucial that when using mechanical ventilation system, air is properly distributed so it reaches every user of a ventilated zone. To improve ventilation systems, and in consequence the air quality, this paper focuses on studying the impact of an air terminal device (ATD) with a dynamically changing geometry on the effectiveness of a variable air volume (VAV) ventilation system. VAV system characterizes a change in the airflow magnitude through the system when the heat gains lower, which may be a risk for human health as air may not reach the furthest parts of a zone. To combat this threat, an ATD with a dynamically changing geometry was installed. As a ventilation quality indicator, the air throw was taken under consideration. Thanks to the new ATD, the steady air throw should be maintained despite the changes in flow in the ventilation system. To achieve this, the research was divided into two stages. The first stage included a series of computational fluid dynamics simulations that considered the alteration of the airflow and the air terminal device diameter. Afterwards, verifying laboratory measurements were conducted on a laboratory stand using a particle image velocimetry (PIV) system that included an air terminal device with a changing geometry. The results of the simulations and the PIV measurements showed that the changes in the geometry of the air terminal device improve the ventilation effectiveness of a VAV system, allowing the system to maintain a constant air throw despite the changing airflow magnitude through the system.