산마늘(Allium microdictyon)과 울릉산마늘(A. ulleungense) 은 수선화과(Amaryllidaceae) 부추속(Allium)에 속하는 다년 초 식물로 산마늘은 우리나라에서는 지리산, 오대산 등의 고산 지대, 울릉산마늘은 울릉도에 분포하고 있다. 본 연구는 산마늘 과 울릉산마늘의 휴면과 발아특성을 조사하여 효과적인 대량증 식법을 위한 기초자료를 제공하고자 수행하였다. 실험은 2021 년 7월에 강원도 정선에서 재배한 산마늘 종자와 2021년 8월에 울릉도에서 채종한 종자를 사용하였다. 수분흡수 실험결과, 산 마늘과 울릉산마늘 모두 수분흡수 3시간 만에 20% 이상의 수분 흡수율을 보여 물리적 휴면이 없는 것으로 판단하였다. 온도 처리(25/15, 20/10, 15/6, 5℃) 실험에서 패트리디쉬에 종자 를 치상 후 30일 이전에 5℃를 제외한 나머지 온도 처리에서 모두 발아가 나타났으며, 산마늘과 울릉산마늘 종자의 발아 적 온은 20~25℃인 것으로 확인되었다. 저온층적(0, 4, 8, 12주)처 리 결과, 산마늘과 울릉산마늘 종자 모두 발아율 향상에는 큰 효과가 없었지만, 저온층적처리 기간이 길어질수록 발아세가 증가하는 양상을 보였다. GA3 처리 결과, 산마늘 종자는 처리 농도 간 유의성이 나타나지 않았지만, 울릉산마늘 종자는 처리 농도가 높아질수록 평균발아일수 및 발아균일도에서 유의적인 차이를 나타냈다. 이러한 결과를 통하여 산마늘과 울릉산마늘 종자는 non-deep PD 유형인 것으로 판단된다.

다결정성 ZIF-8 분리막의 C3H6/C3H8 kinetic 분리 성능 향상을 목적으로 상대적으로 부피가 큰 2, 4-dimethylimidazole (dmIm)이 ZIF-8 구조 내 2-methylimidazole들을 일부 대체한 혼합 리간드 ZIF-8 유사체 분리막을 이차성장법을 이용 하여 제조하였다. 25°C, 1 bar의 feed 압력에서 C3H6/C3H8 (50/50, V/V) 혼합가스를 대상으로 측정된 분리막의 선택도는 ~180이었으며, 이는 기 보고된 대부분의 다결정성 ZIF-8 분리막들의 선택도보다 높았다. 선택도 향상의 원인인 ZIF-8 구조 내 dmIm 도입으로 인한 기공 입구 크기의 축소를 77 K에서의 질소 등온흡착실험과 Maxwell-Stefan model을 이용하여 C3H6 와 C3H8 막투과도 데이터로부터 계산된 확산계수들을 통해 증명하였다.

This study analyzes the aerodynamic and structural characteristics of an H-Darrieus vertical-axis wind turbine (VAWT) under varying inlet velocities using transient analysis. The k-ε turbulence model and six-DOF were applied to simulate urban environments in the flow analysis, while the structural analysis considered blade momentum of inertia and RPM conditions. The numerical results showed that the drag and lift forces increased by 60% and 53% respectively from the nominal wind speed to the cut-off wind speed conditions. Structural analysis indicated that the maximum Von-Mises stress in the blade did not exceed the yield strength of 69 MPa of PC-ABS, ensuring structural stability. However, the connecting rod exceeded the yield strength of SPCC 270 MPa, suggesting potential failure due to repeated rotational loads. This study confirms that materials with a yield strength of more than 1,100 MPa required for connecting rods to ensure reliable operation at high wind speed. These findings provide important insights for the design of robust VAWTs suitable for extreme environments.

This paper introduces a simple and reliable photometric calibration method to extract Hα line flux from narrowband images. The equivalent width of the Hα line (EWHα) is derived using two- and simplified three-filter methods. Synthetic photometry of CALSPEC stars demonstrates the dependency of EWHα on the V − R color, described by a skewed Gaussian function within −0.1 < V − R < 0.7. Systematic errors of the two- and three-filter methods are analyzed under 0%–10% R-band flux contamination. Although the three-filter method underestimates EWHα by 10%, it exhibits less scatter compared to the two-filter method. The simplified three-filter method was validated with the Landolt SA 107 field and surpasses the two-filter method in terms of precision and accuracy. Additionally, applying our method to V960 Mon yields EWHα consistent with high-resolution spectroscopic results.

We investigated the effects of supercritical-CO2 treatment on the pore structure and consequent H2 adsorption behavior of single-walled carbon nanohorns (SWCNHs) and SWCNH aggregates. High-resolution transmission electron microscopy and adsorption characterization techniques were employed to elucidate the alterations in the SWCNH morphology and aggregate pore characteristics induced by supercritical-CO2 treatment. Our results confirm that supercritical-CO2 treatment reduces the interstitial pore surface area and volume of SWCNH aggregates, notably affecting the adsorption of N2 (77 K), CO2 (273 K), and H2 (77 K) gasses. The interstitial porosity strongly depends on the supercritical-CO2 pressure. Supercritical-CO2 treatment softens the individual SWCNHs and opens the core of SWCNH aggregates, producing a partially orientated structure with interstitial ultramicropores. These nanopores are formed by the diffusion and intercalation of CO2 molecules during treatment. An increase in the amount of H2 adsorbed per interstitial micropore of the supercritically modified SWCNHs was observed. Moreover, the increase in the number and volume of ultramicropores enable the selective adsorption of H2 and CO2 molecules. This study reveals that supercritical-CO2 treatment can modulate the pore structure of SWCNH aggregates and provides an effective strategy for tailoring the H2 adsorption properties of nanomaterials.

Hydrogen peroxide (H2O2) is widely used in bleaching treatments in the pulp and paper industry, in wastewater treatment, and as a food additive. However, H2O2 solutions are unstable and decompose slowly when subjected to external factors such as light, high temperatures, or metal compounds. Therefore, a simple and reliable method to measure the concentration of H2O2 is required for its proper use in various applications. We determined the concentration of an H2O2 solution by measurement at a single wavelength (249 nm) without any reagents or complex analytical procedures. In the present work, the measurable concentration of H2O2 was as low as 0.015 wt% (4.41 mM) and as high as 0.300 wt% (88.2 mM), with high linearity (99.99% at 249 nm) between the concentration of H2O2 and the optical density (OD) values. In addition, the method could be used to measure the concentration of H2O2 in a peracetic acid solution without interference from acetic acid and peracetate ion.