• Journal of Mechanical Science and Technology
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• 제15권12호
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• pp.1845-1852
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• 2001

This paper deals with the experiment to obtain quantitative information about conditions of the interface between a water drop and surrounding oil. Velocity distributions in very close region of the interface are measured by introducing a new illumination technique and a telecentric lens. It enables precise measurements of velocity distributions in the close region to the interface. Although the measured velocity distributions exhibit strong influence from the solid wall of an experimental tube, the coincidence of inner and outside velocities on the interface is clearly confirmed for the clean interface. The shearing stresses on the interface, which are proportional to the velocity gradient normal to the interface, clearly show conditions of contaminated interface, which can be divided into two parts. From front stagnation point to somewhere near a separation point, the distribution of shearing stresses is well coincide with that of the Hadamard's analytical solution, while the distribution on the latter part of the interface sows quite different feature, which is supposed to be strongly influenced by contamination of the surface.

• 한국환경과학회:학술대회논문집
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• 한국환경과학회 2003년도 International Symposium on Clean Environment
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• pp.119-122
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• 2003

Quantitation methods of total petroleum hydrocarbons to determinate oil contaminated level in soil were discussed. Extraction characteristics of several pretreatment methods and practical detection limit and reappearances in gas chromatography/mass spectrometry. with each pretreatment method were investigated. The obtained results showed that the newly adopted quantitation method and mechanical shaking extraction method using methanol with extraction solvent are more practical and applicable to real sample than the conventional methods. In applying these methods to gasoline, kerosene, fuel oil which are major source of soil contamination, the practical quantitation limit and % relative standard deviation was able to determine with range of 2.5 - 10 ppm, 5 - 7 ％.

• 지질공학
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• 제16권4호
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• pp.393-402
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• 2006

본 논문에서는 점오염원 형태의 유류누출이 발생되었던 실트질 토양층에서 BTEX와 TPH 성분의 오염특성이 연구되었다. TPH 성분의 토양오염기준별 초과율은 BTEX 성분에 비해 $1.5{\sim}1.7$ 배정도 높았다. BTEX와 TPH 성분의 채취지점별 평균과 최대값은 B-zone>A-zone>C-zone의 순이며, 두 성분 모두 지표면하 $1{\sim}2m$구간에서 오염농도가 가장 높게 나타났다. 오염원에서 수리경사 하부 방향으로 120m와 80m 이내인 지역에서는 BTEX와 TPH 농도가 이격거리에 따라 증가하였으며, 120 m 이상 이격된 지역에서는 토양오염기순 이하인 것으로 나타났다. BTEX와 TPH 성분에 대한 지시크리깅의 제한값으로는 토양오염 확인기준, 우려기준 및 대책기준 값이 적용되었다. 지시변환된 자료의 베리오그램 분석에 의하면, BTEX와 TPH성분 모두 선형모델이 가장 적합한 것으로 나타났다. 선형모델을 적용한 BTEX와 TPH 성분의 확률도에서 토양오염 확인기준과 우려기준의 오염 범위는 유사하게 나타났으나, 대책기준의 오염 범위는 매우 축소되었다. 토양오염 확인기준, 우려기준 및 대책기준에 의해 작성된 확률도에서 BTEX와 TPH 성분의 최대 오염 확률은 BTEX성분이 26%, 26% 및 13%, TPH 성분은 44%, 38% 및 26%인 것으로 추정되었다.

• 한국생물공학회:학술대회논문집
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• 한국생물공학회 2001년도 추계학술발표대회
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• pp.578-581
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• 2001

A treatability study was conducted using a hydrocarbon-contaminated soil for the oPtimization of bioremediation strategy best fit to a given set of contamination. The applicability of nutrients, biosurfactant, and oil-degrading microorganisms were examined by monitoring $CO_2$ evolution and oil degradation The addition of inorganic nutrients in the form of slow released fertilizer accelerated the initial rate of $CO_2$ evolution by a factor of 3. The application of oil-degrading microorganisms did not significantly increased $CO_2$ evolution or biodegradation efficiency. Application of a commercial biosurfactant was most effect in terms of the total $CO_2$ evolution and the oil degradation rate. The results indicate that $CO_2$ evolution measurement was found to be a simple and reliable countermeasure of crude oil hydrocarbon mineralization for the rapid determination of the best-fit bioremediation strategy.

• Food Science and Biotechnology
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• 제18권2호
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• pp.425-431
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• 2009

Antimicrobial coating on chicken carcasses may reduce the effects of cross-contamination and improve product shelf-life and safety. Thyme oil was mixed at 0.5%(v/v) with a pre-gelatinized pea starch coating solution. The coating solution was spread on chicken breast meat after inoculation with selected spoilage and pathogenic bacteria. After inoculation, the chicken meats were packaged in plastic bags and stored at $4^{\circ}C$. During 12 day storage, total aerobic bacteria, lactic acid bacteria, and inoculated organisms were counted at 4 day intervals. Thyme oil treatments reduced the viability of Salmonella as well as the growth of Listeria and Pseudomonas by 2 log CFU/g, and appeared to eliminate inoculated Campylobacter during storage. The addition of thyme oil increased the viscosity of the pre-gelatinized pea starch solution. The results suggested that thyme oil inclusion in an edible starch coating may be a satisfactory delivery system to enhance the safety of processed fresh meat.

• Tribology and Lubricants
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• 제13권2호
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• pp.74-81
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• 1997

The purpose of this study is to develop a cold rolling oil with lubricity and mill cleanness property under the rolling conditions of high reduction ratio and high rolling speed. Six kinds of oil samples were blended. Evaluation of lubricity and anti-seizuro property of the samples were carried out with a laboratory scale rolling mill, where the contact conditions between work roll and strip are very close to actual cold rolling mill. Laboratory evaluation for dispersion, contamination, anti-oil stain property and residual carbon, etc. were carried out with several testers such as longterm circulation tester, Coulter counter and Conradson tester. A new high speed cold rolling oil with good lubricity and mill cleanness property was developed compared with the previously developed rolling oil.

• 해양환경안전학회지
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• 제18권1호
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• pp.61-65
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• 2012

바다에 기름오염 사고가 발생하면 여러 가지 방제 방법 중 물리적 회수 방법을 우선적으로 사용하고 유처리제는 최후 수단으로 고려하는 경향이 있다. 유처리제는 수중으로 기름이 신속히 분산되도록 하여 해수면으로부터 제거하는 방법이다. 해수면으로부터 신속히 기름을 제거하는데 대한 유처리제의 효용성은 널리 증명되어 왔으나 아직도 대부분의 국가들은 해양환경에 미치는 독성을 우려하여 적극적인 사용을 하지 않고 있는 실정이다. 보고된 자료에 의하면 유처리제와 혼합된 기름이 기름 그 자체보다 독성이 더 크게 나타나지 않았다. 멕시코만 기름유출 사고시 미국 정부와 BP사는 최대한 해안에 기름이 도달하지 않는데 중점을 두고 해수면뿐만 아니라 수중의 기름에 대해서도 유처리제를 사용하였다. 유처리제에 대한 순환경편익을 분석하면 유처리제를 사용함으로써 기름이 생태계에 머무는 시간이 줄어들며 장기간 노출을 예방하고 야생동물에 심각한 오염을 방지하는 효과가 있는 등 다양한 연구가 진행되고 있다. 미국 멕시코만 유류오염 사고와 같은 대규모 해양오염사고의 위험이 상존하는 우리 실정에서도 과학적 결과를 바탕으로 한 유처리제 사용의 효용성과 안전성에 대한 검토가 이루어져야 할 시점이라 사료된다.

• Journal of Ecology and Environment
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• 제37권2호
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• pp.41-51
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• 2014

This study investigated the ability of Bothriochloa bladhii (Retz.) S.T. Blake (Poaceae), Cyperus ligularis L. (Cyperaceae), Commelina erecta L. (Commelinaceae), Mariscus umbellatus (Rottb.) Vahl (Cyperaceae), Fimbistylis miliacea L. (Cyperaceae) and Torulinium odoratum L. (Cyperaceae) to clean up various levels of used motor oil (UMO) contaminated soils. The plants were grown in 2 kg garden soils treated to 0%, 1%, 5% and 10% levels of UMO contamination. The plant growth parameters, chlorophyll contents and dry weight of test plants were measured. The phytoremediation ability of these test plants were assessed by measuring the uptake of hydrocarbons in terms of total hydrocarbon content (THC) as well as their percentage degradation values. There was significant (P < 0.05) reduction in leaf chlorophyll contents and dry weights of the test plant species planted in UMO contaminated soils. THC as well as the percentage uptake (or degradation) of hydrocarbons were both lowest in C. ligularis but highest in T. odoratum in all cases. The phytoremediation potential of test plants was highest in soils contaminated with 5% UMO. Based on the results of this study, all test plants with the exception of C. ligularis were potentially capable of undertaking phytoremediation. However, B. bladhii and T. odoratum proved most effective in the uptake and degradation of UMO.

• 한국안전학회지
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• 제21권1호
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• pp.86-91
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• 2006

Oil spills caused by the accidents have been occurred from house and factory waste, grounded tanker, the rupture of storage tank and oil pipelines, the deterioration of various industrial facilities, etc. Many oil spills result in contamination of shorelines and workplace. Fire and explosion may happen from these spills. There are several technologies used for clean-up application, which include use of oil dispersing agents, absorbents, solidifiers, booms and skimmers by physical, chemical, and biological methods. Methods for oil spill clean-up operation are classified into the absorption type, gel type and self-swelling type. Porous materials with oil absorptive properties are classified into micropore, mesopore, and macropore depending on their pore sizes. Recently, new porous materials with smaller size have been developed, but the selective oil absorption in water-in-oil interface demonstrates the macro pore size. In this study oil absorption effects were evaluated using the organic porous materials with a complex function of gel type and swelling type. Samples were subjected to analysis by FT-IR spectroscopy and were characterized in terms of gel formation and morphologies. Oil sorption capacity, pressure retention force and gel strength were also measured. From these results, the physicochemical reactivity before and after gelation was verified and the industrial applications of clean-up operation were suggested.

• 한국지하수토양환경학회지:지하수토양환경
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• 제24권1호
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• pp.17-23
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• 2019

Clean soil environment is of crucial importance to sustain lives of ecosystem and humans. With rapid industrialization, there has been a great increase of soil contamination by accidental releases of petroleum products. In general, soil remediation is an expensive and time-consuming process as compared to cleanup of water and air. Moreover, determining the source and responsible parties of soil pollution often turns into legal conflicts and that further delay the cleanup process of contaminated sites. In practice, total petroleum hydrocarbon (TPH) analysis has been employed to determine the petroleum species and to track down the responsible polluters. However, this approach often suffers from differentiating similar TPH species. In this study, we analyzed TPH chromatogram patterns of 24 domestic petroleum products in specific carbon ranges (${\sim}C_{10}$, $C_{10}-C_{12}$, $C_{12}-C_{36}$, and $C_{36}{\sim}$) and the fractional changes of THP ratio in the mixture products of gasoline, kerosene and diesel. The proposed TPH analysis method in this study could serve as a useful tool to better analyze the petroleum species in soils contaminated with complex oil mixtures, and ultimately be used to identify the polluters of soil.