This study investigated the characteristics of fish communities and distribution of endangered species in the mid-upper reach of Geumgang River, Korea, from September to October 2021. A total of 17,177 fish of 11 families and 46 species were collected from 13 survey stations during the survey period. The dominant species was Zacco koreanus (relative abundance of 17.45%), and the subdominant species was Z. platypus (16.73%), followed by Acheilognathus koreensis (8.49%), Hypomesus nipponensis (8.27%), Pungtungia herzi (7.28%), Coreoleuciscus splendidus (6.80%), Gobiobotia brevibarba (6.58%), Pseudopungtungia nigra (4.67%), A. yamatsutae (3.77%), G. macrocephala (3.38%), and Rhinogobius brunneus (3.04%). Among the collected fish species, 21 (45.65%) were identified as Korean endemics, and two exotic species, Lepomis macrochirus and Micropterus salmoides, were also observed. There were six species of endangered species that were designated by the Ministry of Environment (Class I: P. nigra and Liobagrus obesus; Class II: G. brevibarba, G. macrocephala, Hemibarbus mylodon, and Coreoperca kawamebari). H. mylodon is also a natural monument designated by the Korea Heritage Service. The cluster analysis showed that the dominance index was low, while the diversity and richness indices were high, indicating a stable and healthy fish community. The mid-upper reach of Geumgang River has a well-conserved and diverse aquatic environment and is inhabited by many endangered species and natural monuments. Therefore, continuous attention and systematic management are required.

The thermal management of high-density electronics within military shelters is a critical challenge for ensuring operational reliability, particularly under harsh field conditions involving significant solar radiation. This study presents a numerical investigation using three-dimensional Computational Fluid Dynamics (CFD) to optimize an air-cooling system for an electronics rack housed in a military shelter. Four distinct cooling configurations were analyzed and compared: (1) a baseline model relying on natural convection, (2) a fan-assisted forced convection model, (3) a direct cold air supply model using an insulated duct, and (4) a hybrid model integrating both fans and the duct. Boundary conditions were established based on the high temperature and solar radiation criteria of the MIL-STD-810G standard. To quantitatively evaluate the cooling efficiency of each system, a normalized performance index derived from a weighted sum of the average temperature and temperature standard deviation was employed. The results demonstrate that the baseline configuration leads to critical overheating, with component temperatures reaching up to 124℃. In contrast, the hybrid fan-duct system exhibited the most superior performance, effectively reducing the maximum temperature to 59℃. This is attributed to a powerful synergistic effect, where the qualitative supply of low-temperature air via the duct is combined with the quantitative distribution of flow rate throughout the system by the fans. This study elucidates an effective thermal management strategy for electronics in military shelters exposed to severe environments, identifying the integrated fan-duct system as the most robust and optimal air-cooling solution.

산림지역에서 강우는 수관층을 통과하면서 입자의 크기와 낙하 속도가 변화하게 되며, 이로 인해 수관통과우는 임외우와는 다른 물리적 특성을 나타낸다. 이러한 특성은 산림 내 토양침식 과정에 영향을 미칠 수 있으므로 수관통과우 의 특성에 대해 명확히 이해할 필요가 있다. 본 연구는 광학우적계의 관측 자료를 이용하여 임외우와 수관통과우의 강우입자 크기 분포 및 운동에너지를 비교ㆍ분석하였다. 이를 위해 강원대학교 춘천캠퍼스 내 잣나무림, 참나무림 및 공개지에 각각 1대씩 총 3대의 광학우적계를 설치하여 데이터를 수집하였다. 분석 결과, 중앙부피직경(D50, 평균±표 준편차)은 착엽기의 참나무림(4.20±0.61mm), 잣나무림(3.68±1.04mm) 및 낙엽기의 참나무림(2.32±0.45mm)의 수관통 과우의 순으로, 모두 임외우(1.98±0.76mm)보다 큰 것으로 나타났다. 강우입자의 직경별 부피비는 모든 임분의 수관통 과우가 약 3.0~3.5mm 이상의 직경에서 임외우보다 더 크게 나타났다. 강우운동에너지는 강우입자의 크기 분포와 유사한 경향을 보이며, 동일한 강우강도 대비 착엽기의 참나무림, 잣나무림, 낙엽기의 참나무림 및 임외우의 순서로 크게 나타났다. 이러한 결과는 수관통과우가 잎과 가지에서의 비산과 집적으로 인해 임외우와는 다른 강우입자 크기 분포를 보이며, 임지에 더 강한 운동에너지를 전달할 수 있음을 시사한다. 따라서 산림에서 발생하는 토양침식의 예측 정확도의 제고를 위해 산림의 임분구조에 따른 수관통과우의 입자 분포 특성에 대한 이해가 중요하다고 판단된다.

This study examined the quality characteristics of rice layer cakes prepared using various levels of allulose (ALL). ALL was used to substitute 0% (control group), 25% (ALL-25 group), 50% (ALL-50 group), 75% (ALL-75 group) and 100% (ALL- 100 group) of white sugar (WS) in the manufacture of rice layer cake. The substitution of WS with ALL decreased the pH of the cake batter but increased its specific gravity (p<0.001). The ALL-100 group exhibited higher moisture content than the control (p<0.05), and baking loss increased with increasing ALL levels (p<0.01). The volume index of the cake decreased significantly as the proportion of ALL increased (p<0.001). Low lightness, high redness, and high yellowness were observed in the experimental groups at higher proportions of ALL (p<0.001). The ALL-100 group exhibited significantly higher hardness, adhesiveness, cohesiveness, springiness, gumminess, and chewiness than the other groups (p<0.05). Sensory evaluation revealed that cakes with higher ALL levels had stronger perceived intensity with respect to “color,” “sweet aroma,” and “salty taste.” The acceptance test indicated that the ALL-25 group was comparable to or more acceptable than the control in all attributes except for color.

본 연구는 경상북도(경북; 안동시, 청송군, 영주시, 의성군), 경상남도(경남; 밀양시), 전북도(전북; 장수군), 경기도(경기; 파주시), 강원도(강원; 정선군) 등 한국의 8개 주요 사과 생산지에서 기후변화가 ‘후지' 사과의 수확시기와 과실품질에 미치는 영향을 분석하고자 하였다. 사과 과수원은 경북지역은 위도 36도, 경남과 전북지역은 35도, 경기와 강원지역은 37도에 위치하였다. 그리고 사과의 착색기인 10월 최저 기온은 청송 5℃, 장수 6.4℃, 정선 5.7℃로 전반적으로 낮았으며, 지리적 차이와 관계없이 과실의 수확시기에는 약 10일 정도의 차이가 있었다. 수확시 과실의 경도는 경북과 경남지역 과실은 56.6-64.1 N으로 다소 낮았던 반면, 전북, 경기, 강원지역은 67.8-72.2 N으로 높게 나타났다. 한편, 지역 간 산 함량 및 내생 에틸렌 발생량은 유의한 차이를 보이지 않았으며, 과피의 적색도 또한 청송 25.8, 정선 27.5, 파주 26.2로 비교적 낮은 수준을 보여 재배지 간 뚜렷한 차이는 관찰되지 않았다. 8개 지역의 과실을 수확후 180일간 저온저장하였을 때 안동, 밀양, 파주지역의 과실 경도는 59.4-64.5 N으로 높게 유지되었고, IEC는 87.0-112.5 μL·L-1으로 낮은 경향을 보였다. 그리고 산 함량은 저장기간이 길어지면서 감소하였고, 가용성 고형물 함량은 변화를 보이지 않았다. 따라서 RCP 4.5와 8.5 시나리오에서 기온 상승에 대한 우려에도 불구하고, 현재까지 한국 사과재배 지역에서 ‘후지’ 사과의 과실품질에는 유의미한 차이가 관찰되지 않았다.

Silver nanoparticles (AgNPs) are promising photocatalysts with a broad light absorption range and high catalytic activity. However, conventional synthesis methods often involve toxic chemicals, limiting their environmental applicability. In this study, we developed an eco-friendly bio-templating method to synthesize hierarchical micro/nano-structured silver (MNAg) photocatalysts that uses plant leaves, including Nelumbo nucifera (lotus leaf), Rosa sp. (rose petal), and Limonium sinuatum (statice petal), as natural templates. By modifying the leaf surfaces with citrate functional groups, AgNPs were selectively formed along the microstructures of the templates, preserving their hierarchical morphology. MNAg photocatalysts were subsequently obtained through controlled calcination, and successfully retained the microscale structure of the original template. The surface morphology, chemical composition and crystalline structure of the MNAg were characterized using scanning electron microscopy (SEM), field-emission scanning electron microscopy (FE-SEM), energy-dispersive X-ray spectroscopy (EDS), transmission electron microscopy (TEM), and X-ray diffraction (XRD), confirming the successful formation of hierarchical AgNPs. The optical behavior of the MNAg, characterized with diffuse reflectance spectroscopy (DRS), demonstrated broadened absorption across the visible region, which is attributed to plasmonic coupling among the densely packed AgNPs, partially interconnected along the hierarchical surface. The photocatalytic performance of the MNAg materials was evaluated for methylene blue degradation under UV-Vis illumination. The MNAg derived from lotus leaves exhibited the highest photocatalytic efficiency. This study presents a sustainable route to hierarchical Ag photocatalysts, highlighting the potential of bio-inspired nanomaterials for environmental applications.