• Applied Microscopy
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• 제52권
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• pp.12.1-12.8
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• 2022

The microstructure of diatom frustules found in mud sediments along the coast of Boryeong- city, South Korea, was observed using a scanning electron microscopy (SEM), and the constituent elements of diatoms were analyzed using energy-dispersive X-ray spectroscopy (EDS). Diatom frustules and clay minerals were present in the SEM images of the mud powder. High-magnification SEM images revealed that the surface of the frustules contained identically shaped circular pores, measuring 1 ㎛ in diameter, arranged at regular intervals. This study revealed that the diatom shell fragments in the mud powder ranged in size from 3 to 30 ㎛, with an average thickness of approximately 2.5 ㎛. The elements Si, Al, Fe, K, Na, Mg, and Ti were detected while analyzing the frustule constituents, with Si being the primary component with the highest content.

• 한국해양학회지
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• 제28권3호
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• pp.202-211
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• 1993

해양 부착상 규조류 pseudohimantidium pacificum에 관하여 주사전자현미경 및 광 학현미경을 통한 미세구조, 형태적 변이와 지리적 분포를 연구하였다. 세포의 정축과 횡축의 길이는 기왕의 보고와 유사하였으나 순상돌기의 수는 이보다 2~3개 더 많아 변이가 뚜렸하였다. 조선(striae)의 수도 기보고와 비슷하였고, 이의 모양은 현재까지 둥근형으로 보고되어 있으나 본 연구에서는 긴타원형이었다. 한편 본 규조류는 부유생 활을 할 뿐 아니라 동물부유생물 중 요각류 Corycaeus affinis의 흉각과 두부의 촉각 주변에 많이 부착하고 있었다. 본종이 한국의 남서해역에서 분포하고 있음을 확인하였 던 사실은 이 종이 북태평양의 황해에 37$^{\circ}$30'N까지 분포함을 말해준다.

• KSBB Journal
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• 제29권1호
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• pp.9-21
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• 2014

One of the most abundant microalgaes, diatom is characterized by its unique cell wall structures composed of nano-patterned silica. Due to its highly ordered porosity, these silica frustules, which are found as sediments called diatomite, were used as a cheap adsorption material for water purification. Recently, new emerging nanotechnology compels many researchers to have interest in such diatom's unique properties (eg, nano-scale mesoporosity, photo luminescence, light transparency, etc.) as biogenic inorganic materials as well as the biomass resource (conventional usage of microalgae). In this review, we will focus on the current knowledge about the diatoms research and the possibility of its applications.

• 한국물환경학회지
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• 제33권4호
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• pp.424-433
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• 2017

The purpose of this study is to understand the changes on species composition of the epilithic diatoms and the appearance of morphological abnormalities in the upper region of the Nakdong River where heavy metal inflow is observed. The samples were collected once a week for a month of September 2016 from selecting 7 sampling stations. The heavy metals of cadmium (Cd) and arsenic (As) were not detected during the survey period, but zinc (Zn) was detected in st.4 - st.6 with the range of $0.015{\sim}0.188mg\;L^{-1}$. Metal sensitive species such as Achnanthes convergens, Cocconeis placentula, Cocconeis placentula var. euglypta, Cocconeis placentula var. lineata showed high dominance in st.1 - st.3, st.7. However, metal tolerant species such as Nitzschia palea, Achnanthes minutissima showed high dominance in st.4 - st.6. It is concluded that heavy metal inflow directly affects the changes in species composition of epilithic diatoms. As a result of CCA, the characteristics of the sampling sites were divided into 3 groups. Group 1 was represented the non-detected Zn sites with C. placentula, C. placentula var. euglypta, C. placentula var. lineata. Group 2 was showed the detected Zn sites with Navicula minima and Nitzschia palea. Group 3 was included st.3 - st.7 on 4th week that was stabilized the community structure. Total 8 taxa of abnormal frustules observed. This occurrence of abnormal frustules reflected the temporal and quantitative indicators of heavy metal pollution, in particular, it was confirmed that genus Fragilaria, which has a high abnormality according to heavy metal pollution, can be used as an indicator species.

• 환경생물
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• 제35권4호
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• pp.566-572
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• 2017

2015년 10월부터 2016년 7월까지 가을, 겨울, 봄, 여름의 계절별로 한강 하구의 시암, 성동, 공릉천, 산남, 장항습지 등 5개 습지에서 동물플랑크톤 채집을 실시하였다. 25종의 윤충류를 포함하는 총 46종류의 동물플랑크톤이 출현하였다. 기수종은 요각류 2종만이 출현하였고 10월에 성동과 장항습지에 출현한 15종류가 가장 다양하게 출현한 것이었다. 최대 출현량은 3월에 시암습지에서 윤충류의 대량 출현에 의해 $8,000indiv.\;L^{-1}$로 기록되었다. 3월에는 다른 정점에서도 $5,000indiv.\;L^{-1}$ 이상의 높은 출현량이 나타났지만 나머지 기간 중에서 수백 개체의 낮은 밀도가 지속되었다. 종다양성지수는 0.4~1.8 사이에서 변동하였다. 요각류 유생의 장내용물질 분석 결과 미동정물질들과 함께 규조류가 주먹이원인 것으로 밝혀졌다. 수온은 $10.1{\sim}28.2^{\circ}C$, pH는 7.1~8.6 용존산소량은 $4.5{\sim}11.0mg\;L^{-1}$ 사이에서 변동하여 정점에 따라 하계 수온상승에 의한 용존산소량 부족 가능성이 제기되었다.