• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.5
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• pp.212-217
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• 2015

Ships and marine structures have a lot of problems in their high maintenance and operating cost by biofouling. A biofouling occurrs by the adhesion of marine microorganism, algae and bacteria. In this study, the aim is to prevent or to reduce the biofouling phenomena through silver nano-particle coating on artificial light-weight aggregates and geopolymer. The antibacterial activity on them is tested according to ASTM E2149-2013a. The test results showed, it is estimated that silver nano-particles removed 99.99 % of bacteria. Specimens were set up in the sea side of field test area in Korea Institute of Ocean Science and Technology (KIOST) and have been observed for five months. The anti-biofouling effect and difference in weight change rate have been detected two months later after the installation. Because silver nanoparticles inhibit bacterial growth and kill the cells by destroying bacterial membranes, silver nano-particle coating on artificial lightweight aggregates is a well-suited and eco-friendly method for preventing biofouling in the sea up to 5 months.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.2
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• pp.82-87
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• 2013

Effects of material surface property, hydrophobic or hydrophilic, on the bio-fouling occurred on the bodies submerged in the sea water are investigated experimentally. 4 test models are used in the experiment, which includes aluminum foil in common use, AAO applied hydrophobic surface, HDFS coated hydrophobic surface and hydrophilic surface. Hydrophobic surfaces with numerous micro & nano-scale pillars on it seems to play very important role of preventing them from fouling in initial stage while the effects disappear in long term sense of fouling process. It is concluded that the surface hydrophobicity retards the initial fouling until the fouling thickness is smaller than the heights of the pillars on it but the effects diminish with the fouling proceeds so that the thickness grows bigger than the pillar heights.

• Proceedings of the Korean Society of Broadcast Engineers Conference
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• 2021.06a
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• pp.283-285
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• 2021

본 논문에서는 수중에서 선박 하부에 붙은 오손생물(fouling organism)을 탐지하고 격자지도(grid map)로 나타내는 시스템을 제안한다. 제안하는 시스템은 소나(sound navigation and ranging: SONAR) 센서와 오손생물사이의 시간 데이터를 수집한 후, 라즈베리 파이 4(raspberry pi 4)에서 수집된 데이터를 이용해 격자지도에 맵핑(mapping)함으로써, 선저하부의 상태를 파악하는데 도움을 줄 수 있다. 본 논문에서는 제안된 지도 시스템을 이용하여 선박 하부에 붙은 오손생물의 분포를 확인할 수 있다.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.25 no.5
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• pp.218-224
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• 2015

Recently, removing methods of red tide has been attempted by filtering the organisms using the ceramic porous bodies. However, the marine biofouling could be developed on the surfaces of porous ceramic body after use for more than one month, and it might decrease the function of the specimen. In this paper, a method of inhibiting marine biofouling by changing the physical properties or surface-modification of ceramic porous body was studied. After experiment with six different ceramic porous bodies, it was found that the specimen of lower porosity and water absorption showed the least amount of biofouling. In addition, by increasing the surface roughness with silica particles bonded to the surface of specimen, the amount of biofouling caused by large marine life such as barnacle and mussel could be decreased. On the other hand, when the surface of specimen was coated and fused by glass powder, the amount of biofouling was rather increased. This might be due to eluted inorganic ions from the glass which can promote the growth of the microorganism. In conclusion, the environmental-friendly methods to reduce the amount of marine biofouling, such as controlling the physical properties and the surface roughness of the porous ceramics, can be possible without the use of dangerous substances. So it is expected for the results obtained to be applicable to a marine structure.

• Applied Chemistry for Engineering
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• v.23 no.1
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• pp.71-76
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• 2012

Biofouling by marine organisms such as algae and barnacles causes lots of significant problems in marine systems such as a rise of the maintenance-repair cost for the ship and the marine structures. In this work, a fluoropolymer, perfluoropolyether (PFPE), was applied as an anti-biofouling coating material that prevents the adhesion of marine organisms and facilitates the removal of them. Water contact angles of various surfaces were tested to examine the hydrophobicity of the PFPE-modified surface. The PFPE-modified surface showed the water contact angle of $64.5^{\circ}$ which is a remarkable rise from $46.7^{\circ}$ of amine-treated surface. When the substrate was treated with PFPE, the adhesion on the of the barnacle and other marine organisms were repressed around 15% by the enhanced hydrophobicity. In addition, the removal the of the adhered marine organisms were better comparing to that of the surface prepared by PDMS. Surfaces of the substrate treated by PFPE were characterized through physical and chemical methods to analyze the biofouling results. Degree of biomolecular adhesion to the substrate was quantified by the measurement the fluorescence intensity of marine organisms dyed with green fluorescence. PFPE is expected to be applicable not only to anti-biofouling systems but also to medical devices where the prevention of protein adhesion is required.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.4 no.4
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• pp.349-362
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• 1999

To understand the role of protozoa in the early formation of microbial fouling community, the studies on the formation of microbial film, the succession of microbial fouling communities, and the grazing pressure on bacteria population in microbial film were carried out in the laboratory, Inchon outer port and Inchon inner harbour. Bacteria and heterotrophic flagellates formed primary microbial film on the aluminum surface within 6 hours and oligotrich ciliates were observed 2 cells $mm^{-2}$ on the same surface at 9 hours in Inchon inner harbour which had physically stagnant condition. The larvaes of Balanus albicostatus which were dominant meiobenthos in Inchon coastal area attached on the glass surface at the first day of experiment. Heterotrophic flagellates showed maximum abundance of 465 cells $mm^{-2}$ at the 13rd day and ciliates showed maximum abundance of 63 cells $mm^{-2}$ at the 11st day in the Inchon inner harbour. In the Inchon outer port which opens to the outer sea, the maximum abundance of protozoa occurred at early phase, but not so many. The dominant heterotrophic flagellates were Metrornonas simplex and Bodonids. Dominant ciliates were small tintinnids and oligotrich ciliate Strombidium sp., Large Strombidium (oligotrich ciliate) and sessile Acineta turberosa (suctorian ciliate) occurred after 10 days. The attached larvae of Balanus occurred as biofouling organism on the early surface and showed maximum abundance of 18 indiv. $cm^{-2}$ at 7th day. At that time, adult barnacles were observed on the surface and dead barnacles were observed after two days. Except barnacles, the larvaes of Anthozoa sp., Oysters (Crassostrea gigas) and Polychaeta were observed on the surface from 3rd day. 3 benthic copepods including Harpacticus sp., I isopod, 1 polychaeta and 1 gastropoda were observed as predators of the microbial film on the surface after 7 days when microbial film developed very well. Although the ingestion rates of protozoa on the bactctia of the rnicrobi31 film were relatively low, the average grazing rate of protozoa on bacteria was high of 0.058 $h^{-1}$. This implied that the grazing pressure of protozoa influences the mortality of bacteria populations on the microbial film. but protozoa cannot get enough energy from only bacteria on the microbial film.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2011.06a
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• pp.266-268
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• 2011

부표(등부표)는 항로를 표시하거나 항해상의 위험물을 표시하는 중요한 해상교통안전시설이다. 현재 부표(등부표)의 표체가 철재로 되어 있기 때문에 해중 생물에 의한 표체 오손도가 높고, 무거운 표체 중량으로 인하여 설치 이설 보수 등의 어려움이 있다. 또 철재 표체는 선박과의 충돌에 의한 손상이 발생하며 보수 유지에 따른 많은 비용이 소요된다. 이에 이 연구에서는 선박과의 충돌에도 손상이 거의 없고, 가벼워 취급하기 용이하며 아울러 보수유지가 거의 필요 없는 폴리에텔렌폼과 폴리우레탄 소재의 표체의 개발 내용을 제시한다.

• Journal of the Speleological Society of Korea
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• v.8 no.9
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• pp.24-49
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• 1983

대체로 동굴속에서는 태양의 광선이 비추이는 동굴의 입구 부근에서만 자라는 것으로 알려지고 있다. 그러나 동굴이 개발되고 있는 내부 동굴에서는 조명등이 비추이는 부근에 이끼류나 양치류같은 하등식물이 자라게 되는 경우가 있다. 이것은 조명등의 빛과 온도에 관계되는데 이들 하등식물들이 자라게 되므로써 동굴생물의 생태계에 커다란 변화가 생긴다. (중략)

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2010.10a
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• pp.19-22
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• 2010

부표 및 등부표는 항로를 표시하거나 항해상을 위험물을 표시하는 중요한 해상교통안전시설이다. 현재 부표 및 등부표의 표체가 철재로 되어 있으므로 해중 생물에 의한 오손, 무게로 인한 설치, 이설, 보수 등의 어려움이 있으며 무엇보다도 선박과의 충돌에 의한 부체의 손상이 발생하지 않은 철재 표체에 비하여 보수유지가 거의 필요없는 폴리에텔렌폼과 폴리우레탄 소재의 표체의 개발을 제시한다. 이 연구에서는 프로토타입으로서 LL260 표준 표체를 개발하였다.

• Journal of the Speleological Society of Korea
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• v.4 no.4
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• pp.8-12
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• 1979

이제 관광개발된 동굴과 미개발동굴 중 그 대표적인 몇 개동굴의 생물서식에 대한 변화에 대하여 조사기록에 의하여 분석하면 다음과 같다. 즉, 영월의 고저굴은 1975년 임문정 그리고 남궁 준 등의 조사기록에 나타나 있듯이 Gastropoda 2종, Cructacea 5종, Myriopoda 4종, Insecta 17종, 그리고 Mammalia 3종과 Arachnoida 10종등 총 41종을 발표하고있는데 관광개발된 후 3년이 지나 1978년 10월 현재에는 총 28종이 발견되었을 뿐인데 특히 게새우인 Crustacea가 1종, 곤충인 Insecta가 7종밖에 포착되지 않고 있어 많은 동굴생의 오손감소를 나타내고 있다.(중략)