• 수산해양기술연구
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• 제33권3호
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• pp.194-201
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• 1997

Recently with the rapid development in the industries such as an iron mill and chemical plants, these are enlarged by the use of the piping. This piping was encountered the stress corrosion cracking(SCC) because of stress by water pressure and residual stress of welding etc. under industrial water. In this paper, the behaviour of stress corrosion cracking on the weld zone of steel pipe piping water(SPPW) were investigated according to pre-heat before welding in natural seawater(specific resistance : 25$\Omega$-cm). The main results obtained are as follows :1) The stress corrosion cracking for SPPW and SB 41 is most ready to propagate in heat affected zone of weldment. 2) The SCC sensitivity of SPPW on weldment is more susceptible than that of SB 41. 3) The stress corrosion cracking growth of heat affected zone is delayed by the preheat and dry of base metal and electrode before welding.

• 한국물환경학회지
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• 제20권5호
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• pp.447-451
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• 2004

The various pretreatment processes were evaluated to remove organic pollutants of weathered oil contaminated seawater(WOCS) for reverse osmosis desalination process, Biodegradation, coagulation, ultrafiltration, advanced oxidation processes and granular activated carbon filtration were used to evaluate the potential of organic pollutants removal in WOCS. Dissolved Organic Carbon(DOC) was almost not removed by biodegradation in WOCS. DOC was removed by 25% and 10% with the addition of $FeCl_3$ and PAC in WOCS, respectively. The removal efficiency using ultrafiltration(WOCS 500) was about 20% of DOC and 40% of $E_{260}$, respectively. In AOP application of WOCS, the removal of organic materials was improved up to 60% by the combination of $UV/O_3$ compared to UV process. However, 98% of DOC in woes could be removed by granular activated carbon filtration. It is revealed that activated carbon filtration is the best process for the pretratment of DOC removal.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2014년도 추계학술대회 논문집
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• pp.309-309
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• 2014

음극방식법은 피방식체에 외부전원을 인가하거나 보다 활성인 금속을 전기적으로 연결하여 피방식체의 전위가 일정 전위까지 음극분극 되도록 하여 부식을 억제하는 방법이다. 이러한 음극 방식의 결과로 $OH^-$이온이 금속 표면 부근에 생성되고 금속/해수 사이의 pH 증가를 유발하게 되며, 높은 pH는 $Mg(OH)_2$ 및 $CaCO_3$의 석출을 유발한다. 전착 박막은 각각 1, 3, 6, 12시간 및 5, 15, $20mA/cm^2$의 전류 밀도 조건에서 자연 해수, $CO_2$ 가스가 용해된 해수 용액 내에서 스틸 기판 상에 전기적 증착기술을 가해 형성되었다. 상기 조건에서 증착 된 박막의 내용물은 주사 전자 현미경 (SEM) 및 X-선회절(XRD)에 의해 조사되었다. 또한 코팅 박막의 내식성은 전기화학적 양극 분극시험에 의해 평가되었다.

• 한국태양에너지학회 논문집
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• 제29권2호
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• pp.14-21
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• 2009

Recently, alternative energy resources have emerged considerably due to the high oil prices and environment problems. Deep sea water that is one of the natural energy sources can be one of the attractive solutions to reduce the environment problems, and there are already a few examples in some developed countries. In this study, cooling system of deep sea water using heat exchangers of two hotels, located in near Haeundae Bay in Busan, have been analyzed on the quantity of electricity and gas use comparison between existing cooling system and deep seawater cooling system by using E-Quest simulation program. The results of the study showed that the Hotel A approximately saves 370 millions won per year, and the Hotel B saves 248 millions won per year. It means that the cooling system by using deep sea water has great worth to reduce the ratio of fuel sources.

• 통합자연과학논문집
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• 제3권1호
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• pp.19-23
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• 2010

A simple and rapid method is described for detecting nitroaromatic explosives in air or seawater with the use of photoluminescent organosilicon compounds. The synthesis, spectroscopic characterization, and fluorescence quenching efficiency of silafluorenes are reported. Silafluorenes were synthesized from the reduction of dilithiobiphenyl with dichlorosilanes. Two silafluorenes were used for the detection of nitroaromatic compounds. Detection of nitroaromatic molecules, such as 2,4-dinitrotoluene (DNT), 2,4,6-trinitrotoluene (TNT), and picric acid (PA), has been explored. A linear Stern-Volmer relationship was observed for the first three analytes. Fluorescence spectra of silafluorenes obtained in either toluene solutions or thin films displayed no shift in the maximum of the emission wavelength. The photoluminescence quenching occurs by a static mechanism.

• 수산해양기술연구
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• 제29권2호
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• pp.124-131
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• 1993

Recently. with the rapid development in large sea water systems. there occurs much interest in the study of erosion-corrosion. In this study. the mild steel(SB41) was tested by using of a erosion-corrosion test apparatus with fountain-jet and was investigated under the environments of liquid, air-liquid 2 phase flow and solid particle-liquid 2 phase flow. Main results obtained are as follows : 1. The weight loss by corrosion-erosion in air-liquid 2 phase flow are more increased than that in only liquid solution. 2. Effect of air-liquid 2 phase flow on corrosion-erosion sensitivity becomes more sensitive in natural seawater than that in distilled water. 3. The corrosion potential by corrosion-erosion in air-liquid and solid particle-liquid 2 phase flow becomes noble than that of only liquid solution.

• 한국표면공학회:학술대회논문집
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• 한국표면공학회 2012년도 춘계학술발표회 논문집
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• pp.353-353
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• 2012

음극방식법은 가혹한 해수 환경에 노출된 항만 및 해양구조물 등의 부식을 방지함에 있어 매우 유용한 방식법이다. 여기서는 이러한 음극방식 응용 원리에 의해 무한한 자원인 해수를 이용하여 환경 친화적인 코팅막 제작-시도를 하였다. 즉, 본 연구에서는 해수 환경 중 선박 및 해양구조물 등에 주로 사용되는 강재를 기판으로 하여 양극 조건 및 인가 전류밀도를 달리하여 코팅막을 제작하였으며, 조건에 따라 제작된 코팅막을 SEM, EDS, XRD를 통해 조성원소 및 결정구조를 분석하였다. 또한 밀착성 및 내식성 평가를 통해 실용 코팅막으로써의 한계를 보완한 코팅막 제작 프로세스의 기초 설계 지침을 제시하고자 하였다.

• 한국물환경학회지
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• 제27권4호
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• pp.438-444
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• 2011

Magnesium is one of the abundant natural resources in the earth crust and seawater, which is directly related to various organisms activities interconnecting with water-rock system. In aqueous system, magnesium is known to predominantly exist in the form of $Mg^{2+}$ ion which is verified in its $E_h-pH$ diagram. When it is at equilibrium in aqueous system, temperature takes an essential role to complete equilibrium states. This study represents the change of the stable region of magnesium ion according to temperature, and how the consequences would affect aquatic organisms. It was revealed that there is a noticeable tendency shrinking the stable region of magnesium ion in a diagram as temperature increases, and as a result, aquatic bio-species presumably have difficulties to absorb the nutrient. Also, it was considered that the water system would be acidified by decreasing alkalinity.

• Journal of Species Research
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• 제10권4호
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• pp.356-363
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• 2021

Heterotrophic nanoflagellates (HNFs, 2-20 ㎛ in size) are substantially capable of controlling bacterial abundance in aquatic environments, and microbial taxonomists have studied ecologically important and abundant HNFs for a long time. However, the classifications of HNFs have rarely been reported in Korea on the basis of morphology and 18S rDNA sequencing. Here, previously reported five HNFs from non-Korean habitats were isolated from Korean coastal seawater or intertidal sediments for the first time. Light microscopic observations and 18S rDNA phylogenetic trees revealed that the five isolated species were Cafeteria burkhardae strain PH003, Cafeteria graefeae strain UL001, Aplanochytrium minuta (formerly Labyrinthuloides minuta) strain PH004, Neobodo curvifilus strain KM017 (formerly Procryptobia sorokini), and Ancyromonas micra (formerly Planomonas micra) strain IG005. Being morphologically and phylogenetically indistinct from its closest species, all isolates from Korea were therefore regarded as identical species detected in other countries. Thus, this result indicates an expansion of known habitats that range from those of the five isolates in natural ecosystems on Earth.

• 유기물자원화
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• 제8권1호
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• pp.77-82
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• 2000

3개소의 자연갯벌과7개소의 인공갯벌을 대상으로 토양중의 물리화학적, 생물학적 특성 및 미생물호흡량등과 같은 갯벌의 구조와 기능을 비교 평가하므로서 갯벌의 복원 및 창출기술개발을 위한 기초적 자료를 제시하였다. 자연갯벌의 실트함유량, 질소 및 탄소함유량은 인공갯벌보다 높은 것으로 나타났다. 또한 산화환원전위에 있어서도 자연갯벌의 경우는 토양 깊이 2cm이하부터 환원층이 발달되었지만, 인공갯벌의 경우는 토양 표면에서 20cm이상까지 산화층을 나타내었다. 자연갯벌의 미생물현존량은 인공갯벌들과 비교하여 10~100배 높은 값을 나타내었다. 또한 토양중의 미생물현존량과 실트함유량이 가장 높은 상관관계를 나타내었으나, 저서생물과 미생물호흡량은 자연갯벌과 인공갯벌 간에 현저한 차이는 관찰할 수 없었다. 갯벌의 정화기능을 정량적으로 산정한 결과, 인공갯벌이 자연갯벌보다 해수의 정화량이 높게 나타났는데, 이는 자연갯벌보다 인공갯벌이 정화에 관여하는 토양의 투수층이 깊기 때문이라 판단된다. 그러나 인공갯벌 중에도 자연갯벌과 유사한 해수유동의 분포를 가진 지역에서는 자연갯벌과 유사한 구조와 기능을 보유하고 있는 것으로 밝혀졌다. 따라서 해수의 정화기능을 강화하기 위한 인공갯벌의 창출은 가능할 것으로 판단되며, 자연갯벌과 유사한 구조와 기능을 가진 인공갯벌을 복원 또는 창출하기 위해서는 토양 중의 실트과 같은 미소입자의 함유량을 높게 유지하여 미생물현존량을 높게 유지시키고, 실트함유량을 유지하기 위하여 해수의 유동을 약하게 할 수 있는 방안이나 입지조건을 선택하여야 할 것이다.