This study investigated the spatial distribution of dissolved organic carbon and the changes in tidal flat soil characteristics following the flooding season in the closed estuary of the Geumgang River basin. We found that after the flooding season, a brackish water area expanded due to increased river discharge, which also introduced low concentrations of dissolved organic carbon from the river. Dissolved inorganic carbon predominantly originated from the sea in proportion to salinity, indicating that in the closed estuary area, dissolved carbon supplied from the sea remained a significant source even after the flooding season. Additionally, a substantial amount of tidally transported silt and clay was deposited near the estuary dam after the flood, and its effects continued to influence the sediment characteristics downstream in the intertidal zone. As an empirical study in the closed estuary, our results are expected to contribute to conservation measures for the World Heritage Site in the area.

In this study, 41 individuals in 7 locations within CP, MG, UC, and DN map sheets were observed. The MG map sheet had the highest number (n=13) of individuals, while the CP-3 site on the CP map sheet had the lowest number (n=1) of individuals. Land use analysis indicated that the MG site with the highest number of individuals had a high percentage (70.56%) of forest land areas with a small percentage (12.63%) of farmland areas. The CP-3 site with the lowest number of individuals had a small percentage (26.47%) of farmland areas. It also had the highest percentage (32.13%) of residential and commercial areas, covering 19,616 m2. Measurement results of the physical habitat environment for B. karubei indicated a mean substrate of -2.1 (Φm), an average water depth of 63.0 cm, and a flow velocity of 0.2 m s-1. The association rule analysis for co-occurring species revealed that Semisulcospira coreana, Ecdyonurus kibunensis, and Goera japonica had the highest associations among lotic species, while Limnodrilus gotoi and Calopteryx japonica demonstrated the highest association among lentic species.

잠자리목은 습지 생태계의 환경의 질을 나타내는 생물 지표로 알려져 있으며, 이들의 분포와 풍부도는 습지 생태계 평가 및 생물다양성의 척 도로 활용된다. 본 연구는 환경부에서 지정·관리하는 습지보호지역 25개소를 대상으로 습지 유형별 잠자리목 분포 현황을 분석하여 서식지 보전 및 기후변화에 따른 종의 분포 변화에 관한 자료를 제공하기 위해 수행되었다. 조사 결과, 총 10과 67종이 확인되었으며, 잠자리과(Libellulidae) 24종 으로 가장 많이 관찰되었고 하천습지 52종, 산지습지 50종, 호수습지 30종, 인공습지 32종이 확인되었다. 기후변화 생물지표종인 푸른아시아실잠 자리(Ischnura senegalensis)와 연분홍실잠자리(Ceriagrion nipponicum)는 서식지가 점차 북쪽으로 확장되고 있는 것으로 나타났다. 고유종인 꼬마 측범잠자리(Nihonogomphus minor)와 산측범잠자리(Asiagomphus melanopsoides)는 개체군 크기가 작아 지속적인 모니터링을 통한 관리 방안이 필요할 것으로 보인다. 본 연구결과는 습지보호구역에 분포하는 잠자리의 생태적 특성을 조사하여 습지 생태계의 보전과 관리를 위한 기초자료로 활용될 것이다.

This review paper provides a comprehensive analysis of the measurement and distribution of microplastics in the atmosphere and their role in the adsorption and transport of organic and inorganic pollutants. Due to their small size, large surface area, and hydrophobic nature, microplastics can adsorb a wide range of pollutants, including volatile organic compounds (VOCs) and heavy metals. These pollutants, strongly bound to the surface of microplastics, can remain suspended in the atmosphere for extended periods, facilitating the widespread distribution of contaminants. Building on existing research, this paper systematically reviews the sampling, pretreatment, and analytical methodologies applied to study microplastics in the air. Furthermore, it examines the influence of environmental factors on the adsorption and desorption dynamics of pollutants associated with microplastics. Various studies indicate that microplastics can interact with pollutants such as heavy metals, organic compounds, and microorganisms to form complex contaminants. These complexes can be transported and redistributed across long distances in the atmosphere, amplifying their environmental and health impacts. This review highlights that microplastics are not merely a pollutant themselves but serve as a vehicle for the migration and dispersion of other contaminants. This dual role emphasizes the significant risks microplastics pose to public health and the environment, necessitating further research and effective mitigation strategies.

This study was conducted to collect data from various regions of Jejudo Island, Korea to establish a more accurate and complete academic listing of mushrooms on the island by identifying and organizing them using base sequence analysis. The investigation was performed over five years, from 2019 to 2023, and included a total of nine sites in the southern, western, and eastern areas of Jejudo Island. In total, 481 unique mushroom varieties were collected during the study. These mushrooms included 387 specimens that were classified into 6 classes, 18 orders, 55 families, 118 genera, and 201 species, and 94 unclassified specimens for which the precise species was not known. The collected mushrooms classified by ecotype consisted of 148 species of saprophytes, 47 species of symbionts, and 6 species of parasites. Differences in occurrence patterns were also observed depending on topographical characteristics and vegetation. Finally, three climate-sensitive biological indicator species and two candidate species were also collected, as well as the tropical mushroom Macrocybe gigantea. This study identified 91 species of mushrooms that were previously unreportedon the Jejudo Island. According to the current findings and those previously reported, 7 classes, 26 orders, 123 families, 399 genera, and 1,102 species of mushrooms have been compiled on Jejudo Island to date.

This study aims to prepare reference data that can be used to improve the size suitability of elderly men’s casual wear. The sizes of men aged 65–84 from the 8th Size Korea were analyzed and compared with those aged 45–54. First, as a result of classifying their body types according to Syzing systems for male adult’s garments (KS K 0050), more than 50% of the drop body types were “a protruding belly type (BB),” and more than 95% of the lower body types were “a thick waist type (B).” Additionally, elderly men with type BB or B were 3–5cm shorter in height, waist height, chest circumference, and hip circumference than middle-aged men. As there are currently only a few brands for elderly men, this means that the following problems may arise: If an elderly man wears a middle-aged man’s top based on his chest size, the chest and hip circumferences are adequate, but the length is insufficient, the waist circumference is insufficient, and the shoulder width is considered to be excessive. Similarly, pants designed to fit a waist size designation for middle-aged individuals will be larger than intended in terms of length, hip circumference, and thigh circumference.

This study determined the minimum size of a representative molecular structure for use in future dynamic analyses of asphalt binders. The minimum representative size, considering factors such as aging, additive types, and temperature variations, was established using density and radial distribution functions. This approach ensures that the structure reflects temperature-dependent property changes, which are critical characteristics of asphalt binders. In this study, the structure of asphalt-binder molecules was generated using the composition proposed by Li and Greenfield (2014) for AAA1. To assess the appropriateness of the molecular structure size, we generated additional structures, X2 and X3, maintaining the same composition as X1, but with two and three times the number of molecules, respectively, as suggested by Li and Greenfield (2014). Silica and lignin were considered as additives, and the aging conditions examined included unaged, short-term aging, and long-term aging. In addition, 11 temperature conditions were investigated. The density and radial distribution functions were plotted and analyzed. The variables influencing the density and radial distribution functions were set as the aging degree of the asphalt binder (unaged, short-term aging, long-term aging), 11 temperature conditions ranging from 233 to 433 K in 20 K intervals, structure size (X1, X2, and X3), and the presence of additives (no additives, silica, and lignin). For density, clear differences were observed based on the degree of aging, temperature conditions, and presence of additives, whereas the structure size did not significantly affect the density. In terms of radial distribution functions, the X1 structure reflected differences based on the degree of aging and the presence of additives but was limited in exhibiting temperature-dependent variations. In contrast, the X3 structure effectively captured temperature-dependent trends, indicating that the size of the molecular structure is crucial when evaluating energy calculations or physical tensile strength, necessitating careful assessment.

This study analyzed the catch data of Chionoecetes japonicus in the offshore trap fishery from 2009 to 2022 to investigate the spatial distribution changes of fishing grounds in the East Sea. The results showed that the center of the fishing grounds consistently shifted offshore and northward from 2009 to 2020, but moved back towards the coastal areas since 2020. When comparing the catch of C. japonicus from the offshore trap fishery between 2009-2015 and 2016-2022, statistically significant differences were found (p<0.01). Analysis of the center of the fishing grounds revealed that they gradually shifted offshore while the fishing grounds were initially concentrated in the coastal areas of the East Sea. This suggests that the center of the fishing grounds moved offshore and northward as the C. japonicus in the coastal fishing grounds decreased. The shift of the fishing grounds back towards the coastal areas since 2020 is attributed to the increased operational costs due to the soaring fuel prices and the impact of the COVID-19 pandemic, which led to a decline in consumer demand for live seafood consumed in restaurants. Consequently, the offshore trap fishery for C. japonicus shifted their focus from offshore areas, which required higher operational costs due to increased fuel consumption and longer fishing times, to coastal areas, that were relatively less costly. This study is the first scientific results of its kind to investigate the formation of fishing grounds and annual changes in the fishing grounds of C. japonicus caught in offshore trap fishery in the East Sea from 2009 to 2022.

The number, size, and material distribution of microplastics (MPs) sized 20-200 μm in the raw water and water treatment processes were analyzed using FT-IR in three water treatment plants in Jeju Province. The number of MPs was detected at 0.075-0.620 MP/L in raw water and 0.040-0.047 MP/L in filtered water, which is relatively lower than the results of other studies. Regarding the size of the MPs, particles sized 20-50 μm in both the raw water and the treated water accounted for the highest proportion, representing 65.6% and 56.3% of the total, respectively. In terms of MP type distribution, polypropylene (PP) was identified as the main type at 58.7%. In the water purification process, the MPs removal efficiency was the highest at 93.5% in the sedimentation and rapid filtration process, followed by 58.4% in membrane filtration and 40.0% in slow filtration. Continuous monitoring of the distribution of MPs in raw water and water treatment processes is recommended.

Effective mixing of different-sized aggregates in mobile asphalt plant dryers is crucial for ensuring high-quality, consistent asphalt production. This study explores the application of spatial analysis techniques, particularly the Discrete Element Method (DEM), to understand and optimize the mixing process of aggregates in drum dryers. The research emphasizes the importance of proper mixing to achieve uniform moisture removal and heating across various aggregate sizes. Larger aggregates heat more slowly, while finer particles risk overheating or being carried away by air currents, necessitating careful management of the mixing process. Using LIGGGHTS, an open-source simulation framework, we conducted DEM simulations to analyze the spatial distribution and behavior of aggregates within a 3D model of a drum dryer. The study considered multiple factors affecting mixing efficiency, including drum inclination, rotational speed, and aggregate feeding frequency. Results indicate that the rotational speed of the drum dryer has the most significant impact on mixing effectiveness. The DEM simulations provided valuable insights into particle movement, heat transfer, and potential segregation issues within the dryer. Further investigations into additional factors that may influence aggregate mixing in drum dryers is recommended, paving the way for improved efficiency and quality in asphalt manufacturing.

본 연구는 스트론튬 이온(Sr²⁺) 처리가 수화 시멘트 복합체의 공극분포 특성에 미치는 영향을 실험적으로 평가하였다. 물- 시멘트비(w/c) 0.3, 0.4, 0.5로 제조된 시멘트 페이스트 시편을 21일간 탈 이온수에서 수중 양생한 후, 각각 두 개의 그룹 으로 나누었다. 첫 번째 그룹은 탈 이온수에서 추가로 7일간 양생하였고, 두 번째 그룹은 30% 질산스트론튬(Sr(NO3)2) 수 용액에서 동일기간 동안 추가 양생하였다. 양생기간 및 조건에 따른 각 시편에 대하여 수은압입법(MIP: Mercury Intrusion Porosimetry)을 사용하여 공극률 및 공극 크기 분포를 분석하였다. 실험 결과, 물-시멘트비가 낮을수록 공극률이 감소하는 것을 확인하였다. 21일과 28일간 탈 이온수에서 양생한 시편 간에는 공극률 차이가 유의미하지 않았으나, 21일 수중양생 후 스트론튬 이온에 7일간 처리된 시편은 공극률이 유의미하게 감소한 것으로 분석되었다. 특히, 물-시멘트비 0.3인 경우 에는 공극률이 33% 이상 감소하는 결과를 보였다. 또한, 공극 크기 분포 특성 분석 결과, 모든 물-시멘트비 조건에서 21 일 양생된 시편에 비해 7일간 추가 양생된 시편은 큰 공극의 양이 줄어들면서 작은 공극의 양이 증가하는 경향을 확인 하였다. 특히, 스트론튬 이온에 처리된 시편의 경우 50nm 이하의 매우 작은 공극의 양이 크게 증가하였다. 이로써 스트 론튬 이온 처리에 의해 수화 시멘트 복합체의 미세조직이 치밀해짐을 확인하였으며, SEM 분석을 통해 이러한 결과를 시 각적으로 확인하였다. 본 연구는 스트론튬 이온을 활용한 시멘트 콘크리트 표면처리 기법이 노후 시멘트 콘크리트 구조 물에 대하여 수분 침투 저항성을 향상시키는 유지관리 기술로서 잠재력을 지니고 있음을 보여준다.

Volatile organic compounds (VOCs) can adversely affect human and plant health by generating secondary pollutants such as ozone and fine particulate matter, through photochemical reactions, necessitating systematic management. This study investigated the distribution characteristics of gaseous VOCs in ambient air, with a focus on interpreting data from a photochemical pollution perspective. This paper analyzed the presence and concentration distribution of VOCs in industrial areas, identifying toluene, m-xylene, p-xylene, and n-octane as the most frequently detected components. Particularly, toluene was found to significantly contribute to the formation of ozone and fine particulate matter, highlighting the need for stricter regulation of this compound. Although n-octane and styrene were present in relatively low concentrations overall, their significant contributions to ozone generation and secondary organic aerosol formation, respectively, emphasize their importance in air pollution management.

Air flow field characteristics in a compact chamber system are indispensable for the efficient development of vehicle aerodynamic performance. In this study, air flow and velocity uniformity in the chamber system were numerically analyzed using the CFD method. Air flows at a uniform velocity from the outlet of the blower, passes fast through the heat exchanger with partial pressure difference, and then moves into the blower inlet. Overall pressure drop through the fan gradually increases with the flow rate. The uniformity varies along the test section, decreasing by 5-10% with distance from the nozzle. These predicted results can be widely used as basic conceptual design data for an efficient vehicle chamber system.

국가 수준에서의 식물다양성보전의 대상은 제한적인 분포를 나타내는 특산식물이다. 본 연구에서는 한국특산식물인 동강할미꽃의 분포 현황을 조사하고 평가하였다. 다음으로 생육지의 식생환경을 조사하였고 각 개체군의 구조를 평가하였 다. 이와 더불어 각 개체군의 활력을 평가하고 비교하였다. 추가적으로 연간생장특성을 관찰하였다. 동강할미꽃의 분포지는 크게 석회암 바위절벽, 능선 바위지대, 석회암지대의 산지 정상부 및 풍화작용에 의해 형성된 사질토양의 생육지로 구분되었다. 함께 분포하는 식물은 지리적인 위치에 따라 구분되었고 각각의 생육지를 반영하였다. 측정된 식물체의 잎 수를 이용하여 평가한 개체군 구조는 안정적인 개체군과 상대적으로 불안정한 개체군이 구분되었다. 상대적으로 어린 개체로 구성된 개체군은 능선 바위지대와 석회암지대의 산지 정상부 및 풍화작용에 의해 형성된 사질토양의 생육지에서 관찰되었다. 석회암 바위절벽의 개체군에서 성숙한 개체의 꽃 수가 가장 많았다. 반면에 석회암 산지의 정상부에 위치한 개체군은 잎 수는 많았지만 식물체의 키가 작고 화서의 수도 가장 적었다. 석회암 지대의 바위절벽에 분포하는 개체는 정착 이후 오랜 기간 동안 생육하면서 종자를 생산하고 확산시킨다고 판단되었다. 반면에 석회암 능선의 분포지와 석회암지대의 산지 정상부 및 풍화작용에 의해 형성된 사질토양의 생육지에서는 환경적인 요인으로 개체의 생장이 제한되었고 석회암의 절벽 분포지에 비해 상대적으로 짧은 생활사 주기를 나타내는 것으로 추정되었다. 동강할미꽃은 이른 봄철에 개화하고 여름철이 시작되기 이전에 열매 성숙과 종자 확산이 완성되었다. 생육지는 여름철을 기준으로 하루 중 7시간 내외로 햇볕을 받는 공간으로 평가되었다. 이것은 생장을 위해 강한 햇볕을 필요로 하는 동강할미꽃이 건조한 조건에서 정착하고 생존하여 생활사를 만들 수 있는 조건으로 생각되었다. 본 연구를 통해 확보된 현황 자료를 바탕으로 동강할미꽃은 위기종(EN)으로 평가하는 것이 타당하다고 평가되었다. 또한 수집된 정보는 향후 IUCN의 국가적색목록평가를 위한 중요한 정보가 될 것으로 예상되었다. 동강할미꽃은 강원도 평창군, 정선군의 석회암 바위 절벽에서 다양한 형질의 개체가 관찰됨에 따라 핵심적인 분포지로 높은 가치를 나타냄을 제안하였다.

황근은 동아시아에서 가장 북쪽에 분포하는 준맹그로브에 속한다. 황근의 식생 분포 변화를 살펴보는 것은 기후변화 로 인한 우리나라의 난대 식생대 변화를 관찰하는데 유용할 것으로 판단된다. 본 연구는 Hibiscus속 준맹그로브와 황근의 지리적 분포 관계를 살펴보고 황근 군락 분포에 영향을 미치는 환경요인을 분석하였다. 황근 군락은 지역과 해안 유형에 의해 구분할 수 있었는데, 그룹 Ⅰ의 경우 깊은 만 안쪽으로 함몰된 지형에 발달한 토양을 기반으로 군락이 형성되어 있으며 초본 염생식물과 함께 출현하였다. 그룹 Ⅱ는 기반암이 많이 노출된 해안 혹은 자갈 해안에서 강한 파도의 영향을 견딜 수 있는 덩굴성 해안 관목과 함께 발달하였다. 그룹 Ⅲ은 일본에 위치한 군락으로 우리나라보 다 다양한 해안 유형에서 나타나며, 100개체 이상 큰 규모의 순군락이 출현하였다. 황근 군락 분포에 영향을 주는 환경요인을 분석한 결과 가장 따뜻한 분기의 강수량이 가장 중요한 요인으로 분석되었다. 본 연구에서는 기후 인자들과 준맹그로브 분포의 관계를 분석하고 기후변화 영향에 대한 황근의 생태적인 반응을 이해하는 기반을 마련하고자 한다.