• 한국지하수토양환경학회지:지하수토양환경
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• 제22권1호
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• pp.13-17
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• 2017

Over 30% of domestic soil contamination has occurred via petroleum products and complex oil. Moreover, contamination by complex oil is more intense than it is by a single petroleum product species. In this study, we analyzed sectional TPH (total petroleum hydrocarbon) pattern and sectional ratio of current domestically distributed petroleum products, such as kerosene, diesel, bunker C, and lubricant and complex oils, to determine pollution characteristics of the soil. In the TPH pattern, kerosene, which is a light distillate, had an early retention time, and lubricant oil, which is a heavy distillate, had a late retention time in the gas chromatogram. In addition, we obtained a complexly contaminated soil via diesel and lubricant oil from the Navy and inspected it for its ratio of complex oil species. The inspection results showed that this soil was contaminated with 85% diesel and 15% lubricant oil. The method developed in this study could be used to determine complex petroleum sources and ratios at sites with accidentally contaminated soil.

• 한국식품저장유통학회지
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• 제4권3호
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• pp.287-293
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• 1997

This study was investigated to viscosity, color, chemical properties, and lipid and fatty acid composition for examination of physical and chemical characteristics of sesame oils. Yield of sesame oil was higher in Ansan sesame than that of Chinese and Dambaek sesame. Viscosity of sesame oils was higher than that of shame oils from Dambaek and Chinese sesame, but turbidity and sedimentation rate were higher in Dambaek's sesame oil than those of Ansan's and Chinese sesame oils. In the acid value, saponification value and iodine value of sesame oils, and chemical characteristics of Dambaek's sesame oil were better than those of the others. The neutral, glycolipid and phosholipid contents of sesame oils were 91.1∼92.1, 2.5∼3.5 and 5.5∼6.4%, respectively. The major fatty acids of sesame oils were oleic, linoleic palmitic and stearic acid. The content of oleic acid was higher in Dambaek's and Ansan's sesame oil than that of Chinese sesame oil, and the content of linoleic acid was higher in Chinese sesame oil than the others. The fatty acid composition of neutral lipid, glycolipid and phospholipid were similar to those of total lipid. The ratio of unsaturated fatty acid and saturated fatty acid was higher in Korean sesame oils than those in Chinese sesame oil. The mineral(Mg, Cu, Fe, In, Al, Mn) content of Korean sesame oils was higher than that of Chinese sesame oil. and heavy metals(Cu, Ag, Pb, Cd, As) were not detected.

• 자원리싸이클링
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• 제2권2호
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• pp.39-44
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• 1993

어룡탄광에서 산출되는 저질인 무연탄 슬러리를 Oil agglomeration 처리법으로 탈수하여 다음과 같은 결과를 얻었다. 저질 무연탄은 기름과 응집체(COM)를 형성하여 물과의 비중차이에 의해서 약 80%까지 분리되고 이때 COM을 만드는 각각 석유, 경유 또는 중유의 첨가량은 시료량의 10%정도이다. 무연탄에서 가연성분을 회수하고 회분을 제거할 수 있는 능력은 기름의 첨가율, 광액 농도, 광립의 입도, 교반시간, 교반강도에 크게 영향을 받는다. 최적조건인 상태에서 가연물질의 회수율은 약 95%까지 증가되었고, 회분의 함유율은 30%에서 13.5%로 감소되었다.

• Corrosion Science and Technology
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• 제13권1호
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• pp.28-35
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• 2014

Recently, the fuel oil of diesel engines of marine ships has been increasingly changed to heavy oil of low quality as the oil price is getting higher and higher. Therefore, the spiral gear attached at the motor of the oil purifier which plays an important role to purify the heavy oil is also easy to expose at severe environmental condition due to the purification of the heavy oil in higher temperature. Thus, the material of the spiral gear requires a better mechanical strength, wear and corrosion resistance. In this study, the heat treatment(tempering) with various holding time at temperature of $500^{\circ}C$ was carried out to the alloy of Cu-7Al-2.5Si as centrifugal casting, and the properties of both hardness and corrosion resistance with and without heat treatment were investigated with observation of the microstructure and with electrochemical methods, such as measurement of corrosion potential, cathodic and anodic polarization curves, cyclic voltammogram, and a.c. impedance. in natural seawater solution. The ${\alpha}$, ${\beta}^{\prime}$ and ${\gamma}_2$ phases were observed in the material in spite of no heat treatment due to quenching effect of a spin mold. However, their phases, that is, ${\beta}^{\prime}$ and ${\gamma}_2$ phases decreased gradually with increasing the holding time at a constant temperature of $500^{\circ}C$. The hardness more or less decreased with heat treatment, however its corrosion resistance was improved with the heat treatment. Furthermore, the longer holding time, the better corrosion resistance. In addition, when the holding time was 48hrs, its corrosion current density showed the lowest value. The pattern of corroded surface was nearly similar to that of the pitting corrosion, and this morphology was greatly observed in the case of no heat treatment. It is considered that ${\gamma}_2$ phase at the grain boundary was corroded preferentially as an anode. However, the pattern of general corrosion exhibited increasingly due to decreasing the ${\gamma}_2$ phase with heat treatment. Consequently, it is suggested that the corrosion resistance of Cu-7Al-2.5Si alloy can be improved with the heat treatment as a holding time for 48 hrs at $500^{\circ}C$.

• 수산해양기술연구
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• 제28권4호
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• pp.418-429
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• 1992

Recently, many researchers make a great effort to develop high efficient marine diesel engines using low grade heavy oil, and also study substitution fuel oil for engines and boilers. In case of Fisheries Vessels, we need to know that fish oil can be substituted for fuel oil. Therefore, it is studied that evaporation, ignition and combustion phenomena of the single droplet of fish oils (i.e., Sardine fish oil, File fish oil and Alaska pollac oil) on heated plane surface to evaluate appropriateness as substitution oil. Methanol and light oil are tested simultaneously to help the evaluation on these Fish oils. The results are summarized as follows: 1. The type of evaporation and combustion is spherical evaporation in case of methanol and light oil. And fish oil blended with light oil was finished after spherical evaporation happen when high temperature. 2. Ignition of Pure fish oil was shorter than that of fish oil blended with light oil. 3. Heat transferred to droplet could make qualitative comparison by contact diameter of droplet with hot surface as time changes. Life time of droplet according to the change of heated surface temperature was greatly influenced by droplet contact condition on the heated surface. 4. As far as combustion phenomena was concerned, apparent diameter of the fish oil droplet increased after ignition and decreased suddenly by internal boiling of droplet. 5. Three fish oils had similar phenomena on the evaporation, ignition and combustion. 6. Evaporation and combustion feature of fish oil could not be shown by coefficient of evaporation velocity of droplet and coefficient of combustion velocity of droplet.

• 대한조선학회 특별논문집
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• 대한조선학회 2008년도 특별논문집
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• pp.46-53
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• 2008

Recently, the synthetic material stern tube bush has been applied by ship owner's requirement because the synthetic material has a merit. That is to say, when stern tube seal is damaged and sea water comes into stern tube, it can work without problem because of water lubricating property. However, the material also has a demerit of temperature rise problem when some factors meets on synthetic material, for example, not sufficient lubrication oil supply and not proper shaft alignment and so on. As known in the world, the RAILKO bush is rampant for synthetic material by some ship owner because of the above mentioned reason. However, the bush has several accidents on large container vessel. Unfortunately or fortunately our yard has a chance to apply the RAILKO bush owing to requirement of specific ship owner. Therefore, it is much more required to approach the accurate shaft alignment analysis. In line with this reason, we had a shaft alignment calculation considering hull deformation and hull flexibility (hull stiffness). Also, in the calculation, we had considered dynamic condition which is reflected he propeller thrust forces and moments and oil film stiffness on the shaft alignment calculation. According to he shaft alignment calculation, bearing slope was applied on the tern tube bush and was measured. The RAILKO bush should be applied the running in procedure according to maker's recommendation for performing the oil film on the bush surface. Finally, the vessels were delivered successfully without any problem with AILKO bush as shown on his paper.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2008년도 제39회 하계학술대회
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• pp.1195-1196
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• 2008

최근, 친환경 물질이면서 광유에 비하여 발화점이 높은 식물성절연유에 대한 관심이 고조되고 있으며 식물성절연유변압기의 사용이 미주 등 해외시장에서 급격하게 증가되고 있다. 본 연구에서는 송전급 식물성절연유변압기 개발을 위하여 액체절연 매질의 고전압 시험법을 검토하고 전극 간 이격 거리에 따른 절연파괴 시험을 통하여 식물성절연유의 절연성능을 평가하였다. Weibull 분포와 전계해석을 이용하여 2% 절연파괴전압을 산출하고 전계분포를 계산하여 기존의 변압기 절연매질인 광유와 비교하였다. 본 연구 결과는 향후 식물성 절연유변압기 제작에 필요한 설계 자료로 활용될 것이다.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 춘계학술대회 논문집
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• pp.87-92
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• 2001

This technical note is intended to introduce a state-of-the-art offshore construction vessel. This unique vessel is for multi-purpose Field Development Ship (FDS) for deepwater to ultra-deepwater. The FDS is a construction vessel with dynamic positioning (DP) system intended to develop offshore oil and gas field in water depth up to 3000 m. The design criteria and main capacities of the vessel are discussed.

• Tribology and Lubricants
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• 제34권5호
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• pp.191-196
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• 2018

Bunker C is used in heavy-lift ships, furnaces, and boilers for generating heat, and power. Bunker C has only four regulations for quality standards and is rarely inspected in Korea. For these reasons, other oils such as used lubricant oil are commonly blended with Bunker C. This illegal mixture of fuel can damage the boilers, engines and affect the environment adversely. In this study, we investigate the fuel properties and perform atomic analysis of illegal Bunker C blended with used lube oil. The test results show that higher quantities of used lube oil in Bunker C have higher flash points, total acid numbers, copper corruption, solid contamination, and metal components. Further, increasing quantities of used lube oil in Bunker C cause lower viscosity, sulfur, and V content. However, adequate sample (approximately 1 L) is needed to evaluate presence of adulterants in Bunker C, we attempted the SIMDIST analysis. In the SIMDIST chromatogram, the used engine oils are detected for longer retention times than Bunker C owing to the high boiling point. We also quantitatively analyzed the lube oil content using SIMDIST.

• 대한조선학회 특별논문집
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• 대한조선학회 2013년도 특별논문집
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• pp.97-102
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• 2013

As the offshore oil and gas upstream industry moves into deeper water, the FPSOs are the cost-effective solution. In the harsh environment such as in North Sea, station keeping and heading control capability obtained through the DP and Position Mooring (DPM) system of FPSOs play important roles to keep the safety. This paper introduces the concept, function and sub-system of the DPM systems which has been applied for the North Sea FPSOs since the late 1980s. The requirements and guidelines of some internationally recognized standards are also described, which are important to build the design basis at the early phases of the project.