The design shear strength equations of RC shear walls have been developed based on their performance under in-plane (IP) loads, thereby failing to account for the potential performance degradation of shear strength when subjected to simultaneous out-of-plane (OOP) loading. Most of the previous experimental studies on RC walls have been conducted in one direction under quasi-static conditions, and due to the difficulty in experimental planning, there is a lack of research on cyclic loading and results under multi-axial loading conditions. During an earthquake, shear walls may yield earlier than their design strength or fail unexpectedly when subjected to multi-directional forces, deviating from their intended failure mode. In this paper, nonlinear analysis in finite element models was performed based on the results of cyclic loading experiments on reinforced concrete shear walls of auxiliary buildings. To investigate the reduction trend in IP shear capacity concerning the OOP load ratio, parametric analysis was conducted using the shear wall FEM. The analysis results showed that as the magnitude of the OOP load increased, the IP strength decreased, with a more significant effect observed as the size of the opening increased. Thus, the necessity to incorporate this strength reduction as a factor for the OOP load effect in the wall design strength equation should be discussed by performing various parametric studies.
목적: 본 연구는 안경수건에 함유된 은나노 입자의 항균효과를 연구하기 위해 수행되었다. 방법: 은나노 입자가 함유된 안경수건과 함유되지 않은 안경수건의 세균수를 비교하였다. 결과: 은나노입자가 함유된 안경수건에서 뚜렷한 세균수의 감소가 관찰되었으며, 이 결과는 안경렌즈에 존재하는 세균에 대해 은나노 입자가 높은 항균성을 가짐을 의미한다. 결론: 가까운 미래에 나노기술을 이용한 항균작용 안경수건의 개발이 기대된다.
In this study, we improved the water-based condensation particle counter in Atmospheric Research Aircraft NARA and investigated the condensation particle number concentration over the Korean peninsula. Pump and set point information were changed to improve the instrument used by aircraft for observation. Ground-based observational result showed that the error between two instruments, which are water-based condensation particle counter and butanol-based condensation particle counter, was 4.7%. Aerial observational result revealed that the number concentration before improvement indicate large variation with unstable condition, whereas the number concentration after improvement indicate a reasonable variation. After improvement, the number concentration was 706±499 particle/㎤ in the West Sea and 257±80 particle/㎤ in Gangwon-do, and these are similar to the concentration range reported in previous studies. Notably, this is the first attempt to use aerial observation with water-based condensation particle counter to investigate condensation particle number concentration.