PLANTAR PRESSURE DISTRIBUTION ANALYSIS OF ALPINE AND BOARDERCROSS SNOWBOARDERS’ CARVING TURNS

Plantar pressure distribution analysis of alpine and boarder-cross snowboarders’ carving turn was performed to provide instructors and snowboarders with scientific and quantitative data for evaluation of the turn. Snowboarders from Korean National Team for 2018 Pyeongchang Winter Olympics were chosen as subjects. To allow on-snow measurements of plantar pressure distribution, the boots were outfitted with pressure sensitive insoles. The carving turn section was divided into 5 events and 4 phases of which force, maximum pressure, and plantar contact area were analyzed. Comprehensive kinematical analysis was conducted which indicated the major features of pressure distribution in two different sporting events. The proposed results can be used as a reference for improvement of the training method in snowboarding

Long-Term Stable Recombination Layer for Tandem Polymer Solar Cells Using Self-Doped Conducting Polymers

Recently, the most efficient tandem polymer solar cells (PSCs) have used poly­(3,4-ethylene­dioxythiophene):poly­(styrene­sulfonate) (PEDOT:PSS) as a p-type component of recombination layer (RL). However, its undesirable acidic nature, originating from insulating PSS, of PEDOT:PSS drastically reduces the lifetime of PSCs. Here, we demonstrate the efficient and stable tandem PSCs by introducing acid-free self-doped conducting polymer (SCP), combined with zinc oxide nanoparticles (ZnO NPs), as RL for PEDOT:PSS-free tandem PSCs. Moreover, we introduce an innovative and versatile nanocomposite system containing photoactive and p-type conjugated polyelectrolyte (p-CPE) into the tandem fabrication of an ideal self-organized recombination layer. In our new RL, highly conductive SCP facilitates charge transport and recombination process, and p-CPE helps to achieve nearly loss-free charge collection by increasing effective work function of indium tin oxide (ITO) and SCP. Because of the synergistic effect of extremely low electrical resistance, ohmic contact, and pH neutrality, tandem devices with our novel RL performed well, exhibiting a high power conversion efficiency of 10.2% and a prolonged lifetime. These findings provide a new insight for strategic design of RLs using SCPs to achieve efficient and stable tandem PSCs and enable us to review and extend the usefulness of SCPs in various electronics research fields