• Ocean and Polar Research
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• 제35권3호
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• pp.219-228
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• 2013

In Korea, more than 300 oil spill accidents occur every year. Despite the frequency, only a small pool of data is available on the initial effect of oil spill on macrobenthic fauna inhabiting rocky shores. The aim of this study was to analyze the variation of macrobenthic fauna composition and community structure on rocky shores, and understand the impact of oil on rocky shore organisms after the Hebei Spirit oil spill. Field surveys were carried out in five regions dose to the wreck site in January, April and September 2008. Polluted sites after the Hebei Spirit oil spill showed that biological index consistently decreased for 9 months limited to breeding and recruitment of organisms by spilled oil. Macrobenthic community was subdivided into 3 groups by species elimination and differences between density of major dominant species: enriched biota community under a relatively stable environment, the second with relatively low ecological index and the last with poor community. In this study, species number did not clearly reflect the effect of oil on the rare and mobile species. However, mean density, biomass and community structure showed the effect of oil by considering breeding activity, decline in recruitment and variation pattern with time.

• Tribology and Lubricants
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• 제28권2호
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• pp.47-55
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• 2012

Generally, to product multi-grade oil like engine oil, a sort of mineral base oil is mixed with a fundamental additive package liquid and a polymer liquid as viscosity index improver in order to improve the lubricating property of base oil. That is, engine oil is the mixture of more than two fluids. Specially, a polymeric type liquid cannot be seen as the linear viscosity like Newtonian fluids. In this research, by using the governing equation describing non-Newtonian hydrodynamic lubrication related with the mixture of incompressible fluids based on the principle of continuum mechanics, it will be compared the bearing performance between the mixture of each liquid to be blended and multi-grade engine oil as a single fluid in a high speed hydrodynamic journal bearing. Further, it is to be found the way estimating the performance of the blended multi-grade engine lubricant in a journal bearing in advance before blending by using the physical properties of mineral base oil, fundamental additive liquid and polymer liquid of viscosity index improver. So, it can be reduced the number of trial and error to get the wanted lubricant by selecting the proper volume fraction of each liquid to satisfy the expected performance and estimating in advance the performance of various multi-grade oils before blending. Therefore, it can be shorten the developing time and saved the developing cost.

• 해양환경안전학회지
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• 제18권6호
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• pp.604-609
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• 2012

우리나라는 대규모 유류오염사고가 발생한 경우 방제자원이 충분하지 않아 방제에 어려움을 겪었으며, 또한 방제에 동원된 어선이 효과적인 방제를 수행하지 못해 작업비용이 거부되는 사례도 이전 사고에서 경험하였다. 이에 대규모 유류오염사고 등을 대비하여 방제자원을 사전에 확보하고 또한 유류오염으로 인하여 많은 피해를 입게 되는 오염지역의 어선을 효율적으로 활용할 수 있는 방안의 일환으로 소형 선박에 장착하여 기름을 회수할 수 있는 효율적 장비를 개발하고 이를 정책화하는 것이 중요한 대안이 될 수 있다. 이를 위해, 본 연구에서 국내 실정에 맞는 소형선박 장착용 기름회수장비 개발을 위한 예비 단계로서 이러한 장비의 장착에 적합한 대상 선박의 선정을 위한 연구를 수행하였다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 추계학술대회 초록집
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• pp.105.1-105.1
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• 2010

바이오디젤 보급 활성화에 따른 식물성 원료유의 가격 상승 및 수급 불안정성 문제를 해결하고자 폐유지를 원료로 바이오디젤을 생산하고자 하는 시도가 이루어지고 있다. 폐유지의 사용은 폐자원 활용 측면에서 의미가 있으며 바이오디젤 생산 단가를 낮출 수 있다. 다양한 폐유지가 산업체로부터 배출되며 이 중에서 dark oil은 식용유 공장에서 식물성 원료유의 정제 과정에서 생기는 부산물로 바이오디젤로 전환 가능한 성분을 포함하고 있다. 본 연구에 사용된 dark oil은 54.9%의 유리지방산과 28.0%의 triglyceride, 4.4%의 diglyceride, 그리고 1% 이하의 monoglyceride를 함유하고 있다. Dark oil의 초기 산가는 109.8 mg KOH/g이었다. 본 연구에서는 dark oil의 유지 부분(triglyceride, diglyceride, monoglyceride)을 유리지방산으로 전환시켜 HAAO(high acid acid oil)을 생산한 후, 고체 산 촉매에 의한 에스테르화 반응을 통하여 바이오디젤을 생산하고자 하였다. 유지 부분의 유리지방산 전환 반응을 위하여 음이온성 계면활성제인 SDBS(sodium dodecyl benzene sulfonate)가 사용되었다. Dark oil:황산:물의 질량비가 10:2:10이고 SDBS가 오일 대비 3%인 조건에서 dark oil의 산가는 190.8 mg KOH/g까지 증가하였고, dark oil:황산:물의 질량비가 10:4:10이고 SDBS가 2%인 조건에서는 산가가 194.2 mg KOH/g까지 증가하였다. 생산된 HAAO을 이용하여 오일 대비 30%의 Amberlyst-15 촉매 하에서 HAAO:메탄올 몰비 1:9인 조건에서 에스테르화 반응을 수행하였을 경우 FAME(fatty acid methyl ester) 함량은 81.3%까지 증가하였다. 고체 산 촉매로써 Amberlyst-15와 가격 면에서 저렴한 PC101을 비교하였을 경우 FAME 함량은 각각 80.7%, 77.9%로 비슷한 효율을 나타내었다. 생산된 바이오디젤의 FAME 함량을 높이기 위해 증류 공정을 필요로 하였다.

• 한국발생생물학회지:발생과생식
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• 제20권3호
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• pp.255-266
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• 2016

The optimum concentrations of clove oil as an anesthetic for olive flounder (Paralichthys olivaceus) and the stress response of the fish to clove oil anesthesia were determined over a range of water temperatures, and investigated in a simulated transport experiment using analysis of various water and physiological parameters. While the time for induction of anesthesia decreased significantly as both the concentration of clove oil and water temperature increased, the recovery time increased significantly (P<0.05). The plasma cortisol concentration in fish at each temperature increased significantly up to 12 h following exposure (P<0.05), then decreased to 48 h (P<0.05). The DO dissolved oxygen concentrations, pH values, and the fish respiratory frequencies decreased over 6 h following exposure to clove oil in all experimental groups (P<0.05), whereas the $NH_4{^+}$ and $CO_2$ concentrations in all experimental groups increased up to 6 h (P<0.05). The pH values and DO concentrations increased with increasing clove oil concentration (P<0.05) in the 6 h following exposure, and the $CO_2$ and $NH_4{^+}$ concentrations and the respiratory frequencies decreased with increasing clove oil concentration (P<0.05). The results of this experiment suggest that clove oil reduced the metabolic activity of olive flounder, thus reducing $NH_4{^+}$ excretion and $O_2$ consumption. In conclusion, clove oil appears to be a cost-effective and efficient anesthetic that is safe for use and non-toxic to the fish and users. Its use provides the potential for improved transportation of olive flounder.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집E
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• pp.772-776
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• 2001

The flow structures of turbulent shear layer behind oil fences with different tip configurations were investigated experimentally using flow visualization and PIV velocity field measurement. An oil fence was installed in a circulating water channel and the flow structure around the fence tip was mainly analyzed in this experiment. The four tip configurations tested in this experiment are knife edge; semi-circle edge, circular edge and rectangular edge. The 300 instantaneous velocity fields were measured using the single-frame PIV system and they were ensemble averaged to give the mean velocity field and spatial distribution of turbulent statistics. Free stream velocity was fixed at 10ms/sec and the corresponding Reynolds number based on the fence height was Re=4000. As a result, for the oil fence with rectangular edge, the streamwise velocity component was decreased. On the other hand it was increased for the oil fence with circular edge. For all four fences tested in this study, general flow pattern of the lower shear layer is analogous but the upper layer shows difference depending on the tip configurations. The oil fence with circular edge has more diffusive upper shear layer than that of the others. The shear layer of the oil fence with rectangular edge has relatively thin thickness. The oil fence with circular edge was found to be proper shape for tandem fence.

• 전기학회논문지
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• 제56권9호
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• pp.1561-1565
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• 2007

According to thermal degradation on power transformers, it is known that electrical, mechanical and chemical characteristics for power transformer's oil-paper are changed. In the chemical property, especially, when the kraft paper is aged, the cellulose polymer chains break down into shorter lengths. It causes decrease in both tensile strength and degree of polymerization of paper insulation. Also the paper breakdown is accompanied by an increase in the content of various furanic compounds within the dielectric liquid. It is known that furanic components in transformer oil come only from the decomposition of insulating paper rather than from the oil itself. Therefore the analysis of furanic degradation products provides a complementary technique to dissolved gas analysis for monitoring transformers when we evaluate the aging of insulating paper by the total concentration of carbon monoxide and carbon dioxide dissolved in oil only. Recently, the analysis of furanic compounds by high performance liquid chromatography(HPLC) using IEC 61198 method for estimating degradation of paper insulation in power transformers has been used more conveniently for assessment of oil-paper. It is know that the main products which is produced by aging are 2-furfuryl alcohol, 2-furaldehyde(furfural), 2-furoic acid, 2-acetylfuran, 5-methyl-2-furaldehyde, and 5-hydroxymethyl-2-furaldehyde. For investigating the accelerated aging process of oil-paper samples we manufactured accelerating aging equipment and we estimated variation of insulations at $140^{\circ}C$ temp. during 500 hours. Typical transformer proportions of copper, silicon steel and iron have been added to oil-paper insulation during the aging process. The oil-paper insulation samples have been measured at intervals of 100 hours. Finally we have analyzed that 2-furoic acid and 2-acetylfuran products of furanic compounds were detected by HPLC, and their concentrations were increased with accelerated aging time.

• 통상정보연구
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• 제14권3호
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• pp.209-227
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• 2012

글로벌 금융위기의 진원지인 동북아시아 지역은 전통적으로 석유의 생산 및 소비 불균형이 심화된 지역이며, 최근에는 급증하는 석유거래로 인해 저장 및 수송설비의 부족현상까지 겪고 있어 안정적 석유 공급을 위협하고 있다. 따라서 동북아시아 지역 내 독립적인 석유물류허브 기능을 갖춘 시설과 석유거래의 기능까지 담당할 수 있는 시장의 형성이 요구되고 있다. 본 연구에서는 동북아 지역의 석유물류허브 구축 후보 국가를 대상으로 한 석유산업 관련 설비인 정제시설의 정태적 및 동태적 효율성 분석을 통해 시사점을 도출하였다. 동북아 역내 주요 국가들의 석유정제설비의 효율성은 우리나라가 가장 높은 것으로 나타났으며 우리나라가 동북아시아 지역의 석유물류거점의 역할을 수행하기 위해서는 정부의 적극적인 정책지원이 필요하다.

• 한국식품영양학회지
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• 제25권4호
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• pp.968-973
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• 2012

This study analyzes the structure types of salmon oil to evaluate the purity of salmon oil products based on the 38 different types of imported salmon oil products distributed in the Republic of Korea. The major types of omega-3 foods in the salmon oil are ethyl ester (EE) and triglyceride (TG). If the salmon oil contained potential contaminants and was processed in order to remove it, EE type omega-3 fatty acids are found in concentration. This provides a good guide in assessing if products were made with EE type ingredients or re-esterified contaminated materials. The results of the FT-IR analysis showed significant difference in the C=O, C-O band positions in TG and EE. There were 19 TG type products and 19 EE type products. The analysis of carbon isotope ratio was performed on the types of TG and EE. There were different properties in the 19 TG type products. In one product, the carbon isotope ratio was -25.15 and the other 18 products showed -22.15~-23.96. The carbon isotope ratio of all 19 EE type products showed -21.91~-23.74. The results of the TLC analysis showed similar results with FR-IR. The re-esterified TG form was not detected in the TG type products, confirming that the TG type products contained natural salmon oil. This study aimed to provide the basic material in classifying the types of natural salmon oil and re-esterified salmon oil, by analyzing the pattern and proportion of FT-IR spectrum, carbon isotope ratio, and TLC.

• 한국미생물·생명공학회지
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• 제21권1호
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• pp.74-81
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• 1993

저온성 세균 Acinetobacter calcoaceticus A1-1의 유류분해 특성을 연구하기 위해 환경적 요인에 대한 영향을 살펴보았다. 이 세균의 성장율과 유화활성도에 대한 적정 환경조건은 온도 $15^{\circ}C$, pH 7.5, 염분도 0-3, 원유농도 0.1로 나타났고 질소원과 인원의 적정농도는$(NH_4)_2S0_4$과 $K_2HP0_4$, 형태로 각각 0.76 mM, 0.057mM이다. 온도에 따른 A.calcoaceticus A1-1의 유류분해 양상을 개스크로마토그라피로 분석한 결과 $10^{\circ}C$, $15^{\circ}C$에서 대부분의 탄화수소 피크가 감소되어 상당 정도의 유류분해를 관찰 할 수 있었다. 반면 $25^{\circ}C$의 경우에는 120시간 배양한 후에도 원유에 포함된 포화탄화수소 화합물들이 부분적으로만 분해되었다.