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Distribution of rare earth elements and Yttrium in deep-sea sediments and current research status
No full text희토류 원소와 이트륨(REY)은 산업에 필수적인 자원으로, 타 대양에 비해 태평양 심해퇴적물에서 상대적 고농도로 부존함이 확인됨에 따라 대체 자원으로서 주목받고 있다. 본 논평은 태평양을 포함한 주요 해양에서 REY 분포 특성과 배태광물(host phase), 농집 기작 및 형성 시기에 관한 연구를 종합하여 REY의 분포 및 거동에 대해 지화학적인 이해를 돕고자 하였다. 심해퇴적물에서 REY는 특정 깊이의 층준에서만 고농도로 산출되며 그 깊이는 해역간, 해역 내에서 서로 다르게 나타난다. 이는 서로 다른해양환경 하에서 특정 지질 시대에 집중된 농집 사건의 존재를 시사한다. REY 농집에 있어서 생물기원 인회석이 주요 배태광물로작용하며, 철-망가니즈 산화물(Fe-Mn oxides)은 이차적 공급원으로 기능한다. REY 농집은 심층해류 강화 등의 고해양학적 조건과 밀접한 관련이 있으나 REY 고함유층의 연대 및 분포는 낮은 퇴적률, 해저지형의 복잡성 등의 환경 조건으로 인해 분석 및 고환경적 해석에 한계점이 존재한다. 본 논평은 이러한 제한 사항을 검토하고, 향후 정밀한 연대 모델과 복수의 코어에 기반한 통합 연구의 필요성을 제안함으로써 REY 농집 사건의 고해양학적 의의를 도출하고 향후 함REY 심해퇴적물의 효율적 탐사에 기여하고자 한다.33Nscopuskc
EXTRACTION OF COASTLINE AND VOLUMETRIC CHANGE ANALYSIS USING SENTINEL-2: A STUDY IN FUNAFUTI, TUVALU
No full textCoastal alterations pose significant risks to low-lying and geomorphologically fragile atoll islands. Therefore, spatio-temporal analysis of coastal dynamics is essential for understanding their morphological evolution. Thus, this study investigates coastal changes in Funafuti Atoll, Tuvalu, using Sentinel-2 satellite imagery from 2019 to 2020. The Sentinel-2 imagery is preprocessed through reprojection and resampling to ensure spatial accuracy, followed by segmentation and normalized difference vegetation index (NDVI) calculation. Land and water are then differentiated using thresholding, allowing for the extraction of the coastline boundary. The study depicts that between 2019 and 2023, Funafuti's coastline length and land area enclosed by the coastline boundary declined by 2.9% and 7.3%, respectively. Future research will integrate sea level data to adjust the digital elevation model (DEM) data, assess shoreline shifts, and quantify erosion and accretion through volume analyses.1
Novel scFv detection system targeting the glycoprotein of harbor porpoise Rhabdovirus (HPRV) through computational and experimental validation
No full textHarbour Porpoise Rhabdovirus (HPRV), with its distinct bullet-shaped nucleocapsid and negative-sense RNA genome, has become a subject of concern owing to its cytotoxic effects on marine mammals and the potential risks associated with zoonotic transmission of a recently discovered rhabdovirus affecting Harbor porpoises. Existing diagnostic techniques for marine viruses are limited, especially for cetaceans. scFv technology offers a potential alternative because of its compact size, specificity, and efficient production capability in the E. coli system. This study focused on the characterization and development of a prospective diagnostic system using scFv antibodies to identify HPRV. Through the biopanning selection process, high-affinity scFv candidates were discovered and subsequently subjected to expression optimization, purification, molecular docking and dynamics simulation were conducted to evaluate their binding affinities against HPRV glycoproteins. Thus, ELISA binding affinity and specificity tests validated scFv(G2) as the best candidate with significant specificity and sensitivity for HPRV antigen detection without cross-reactivity with host proteins. We proved that the scFv double domain compared is preferable to single domain after antigen interaction based on computational evaluation. This study offers essential insights into an scFv-based diagnostic tool, enhancing the detection capabilities of marine rhabdoviruses in cetaceans and facilitating potential applications in zoonotic virus control.1
Design and Study of a New Wave Actuator for a Boat
No full textThe design and analysis of a new wave actuator for boats is presented in this paper. The wave actuator is installed beneath the boat hull and converts the hydrodynamic forces generated by rising waves on the boat into translational thrusting forces. The wave actuator consists of a flexible water tank, revolving springs, and inlet/outlet nozzles to enable passive wave-driven thrust generation without intermediate energy conversion. The compressed water in the tank of the wave actuator is expelled by the wave pressure exerted on the actuator, and the water thrust out of the nozzles propels the boat forward. The dynamics and hydrodynamics of the new wave actuator are newly modelled using second-order differential equations in this paper. The hydrodynamics of the boat with the wave actuator is mathematically analyzed, and the energy conversion capability of the wave actuator is analyzed. The results demonstrate that at a wave frequency of 0.3 Hz, the system achieves a cruising speed of 6.098 m/s and a high energy conversion efficiency of 67.9%. These findings highlight the actuator’s potential for efficient and sustainable marine propulsion in regular sea conditions.11Ysciescopu
Development of an Artificial Seaweed Mat Method for Scour Reduction around Suction Foundations in Offshore Wind Power
No full text최근 기후변화 대응과 탄소중립 실현을 위한 글로벌 정책 기조에 따라 해상풍력 발전이 주목받고 있으며, 이에 따라 해상풍력 구조물의 기초 형식 중 하나인 석션 기초의 활용도도 점차 증가하고 있다. 석션기초는 빠른 시공성과 환경친화성, 재사용 가능성 등의 장점으로 해양환경에 적합한 기초 형식으로 평가받고 있으나, 대구경 구조물의 특성상 해저면과의 접촉 구조물 주변에서 유속 변화에 따른 세굴 현상이 심화되는 문제가 있다. 이러한 세굴은 구조물의 안정성에 직접적인 영향을 미치며, 특히 석션기초는 그 구조적 특성상 세굴에 매우 취약하다. 기존의 세굴 방지 대책으로는 돌망태, 콘크리트 매트리스, 보호블록 등의 물리적 차단 방식이 사용됐으나, 시공의 복잡성과 해양 생태계에 미치는 영향 등에서 한계가 존재한다. 최근에는 이러한 한계를 극복하고자, 해양 생태계와 조화를 이루며 구조적 안정성도 확보할 수 있는 친환경적 세굴 저감 기술에 대한 필요성이 대두되고 있다.본 연구에서는 이러한 문제점을 해결하는 방안으로, 인공해조매트를 활용한 세굴 저감 공법을 제안한다. 이 공법은 해양식물의 자연적인 흐름 분산을 모사하여 구조물 주변의 유속을 저감시키고, 와류 생성을 억제함으로써 세굴 저감을 효과적으로 완화하는 것을 목표로 한다. 동시에, 인공 해조는 해양 생물의 서식처로 기능하여 생태적 가치도 제공할 수 있다. 인공해조매트의 세굴 저감 효과를 검증하기 위해 실해역 조건을 고려한 1/2~1/5 축소 모형 실험을 수행하였으며, 공법 적용 여부 및 설계조건 변화(매트 크기, 해조 배치 형상 등) 에 따른 세굴 경향을 비교·분석하였다. 이를 통해 구조물의 안정성을 확보함과 동시에 해양 생태환경 보호를 고려한 해상풍력 기초로 활용되는 석션기초에서 인공해조매트의 세굴 저감 공법 기술을 개발하고자 한다.2
Toward operational monitoring of floating Sargassum macroalgae
No full textFloating Sargassum in the East China Sea and adjacent waters serves as important habitats for diverse marine organisms including commercially valuable fish species. Additionally, there is grow- ing interest in utilizing them as a carbon storage medium by absorbing carbon dioxide through photosynthesis. However, the proliferation of this brown macroalgae often becomes problematic when it washes ashore in large masses. Since 2015, these Sargassum landings have caused sig- nificant economic losses to local aquaculture, tourism and the fishing industries in Jeju island and the southwest coastal region of the Korean peninsula. According to the Korean government, annual landing of Sargassum patches on Jeju Island range from 200 to 12,000 metric tons varying across different years. The amount of Sargassum influx fluctuates significantly each year, and since it mostly drifts with ocean currents, monitoring at both broad and local scales is crucial. While typical ocean color satellite data are used for large-scale monitoring, their low spatial resolution (>250m) and infrequent observation make them inadequate for detecting Sargassum patches near the coast or aquaculture farms. Recently, geostationary ocean color satellites and high-resolution polar-or- biting satellites, such as Sentinel-2/MSI (10m, 20m) and Landsat-8,9/OLI (30m), offering better op- portunities for monitoring both open seas and coastal areas. Furthermore, in emergency situations, commercially available PlanetScope imagery (3-4m) can be used for intensive monitoring. Howev- er, these optical satellites have a fundamental limitation—they cannot see the surface under cloud cover—so surface ocean current prediction by models can be exploited. Additionally, recent studies have explored the use of Synthetic Aperture Radar satellites, which are unaffected by clouds, for detecting floating algae. However, satellites like Sentinel-1 have significantly lower sensitivity com- pared to optical satellites. Here, we examine the strengths and weaknesses of various satellite ob- servations, discuss current monitoring strategies, and explore future directions for improvement.1
Three new species of Lichomolgella Sars G.O., 1918 (Copepoda, Cyclopoida, Sabelliphilidae) associated with Bryozoa in Korea
No full textThree new species of Lichomolgella Sars G.O., 1918 are described as associates of bryo-zoan hosts from Korea. In all three species, the endopod of leg 1 is two-segmented, unlike the two previously known species of this genus. As additional diagnostic features, L. exigua sp. nov. has a two-segmented endopod in legs 2 and 3, L. collata sp. nov. has one claw plus two setae on the third segment of the antenna and an inner coxal seta on legs 2 and 3, and L. nudicoxa sp. nov. lacks an inner coxal seta on all swimming legs. The genus Lichomolgel-la is transferred from the family Lichomolgidae to Sabelliphilidae and can be characterized by several diagnostic features, such as a claw in addition to setae on the second endopodal segment of the antenna, a single-segmented endopod of leg 4 bearing two distal spines, three spines plus five setae on the third exopodal segment of legs 3 and 4, a claw-like prox-imal scale on the mandibular gnathobase, and a vestigial distal lash of maxilla.11Ysciescopu