• 한국식생활문화학회지
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• 제23권1호
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• pp.26-32
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• 2008

: In this experiment, three samples of oils were used. These oils were hydrated soybean oil, pure soybean oil and regular soybean oil. Oil was used after heating at $235-240^{\circ}C$ every four hours term and total heating hours was 16 hours. The physio-chemical analysis and sensory evaluation were performed on these oils. The hydrated soybean oil showed lower acid, peroxide and carbonyl value than the other two oils (p<0.05 or p<0.001). The other two oils were more affected in rancidity than the hydrated soybean oil. In color test, whereas L value lowed during the heating time, a and b value increased during the heating time. The tendency of high L value and low b value in a long-time heating was more apparant on the pure soybean oil and the regular soybean oil than on the hydrated soybean oil (p<0.05). In sensory evaluation, color and rancidity order increased during the heating time. The hydrated soybean oil showed color and rancidity order than the other two oils. In overall quality test, the pure and regular soybean oil that had been used for 12 and 16 hour were not preferable. The hydrated soybean oil that had been used for 16 hour were not preferable. In sensory evaluation, the hydrated soybean oil, the pure and regular soybean oil did not show a apparent difference, although the hydrated soybean oil had a little better scores on the overall quality.

• 설비공학논문집
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• 제6권4호
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• pp.388-398
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• 1994

Computer simulation model for predicting more accurately the heat transfer performance of the evaporator and condenser which have significantly affected on the performance of air-conditioner has been suggested. In this model oil and micro-fin tube used in a actual unit are considered to simulate the more realistic case. The effects of oil and micro-fin tube on the performance of an air-conditioner have been investigated. It is found that the present model requires higher pressure than the existing model due to the characteristics of the tube considered. However, it turns out that the present model is very close to an actual cycle. As the amount of oil inside the tube increases, condensation heat transfer coefficient shows a linear decrease irrespective of a kind of oil, while evaporation heat transfer coefficient increases slightly in the oil with low viscosity and decreases exponentially in the oil with high viscosity. Pressure drop in both evaporator and condenser increases linearly irrespective of a kind of oil. It is also found that the effect of the variation of oil concentration on the magnitude of two-phase region is negligible.

• 한국응용과학기술학회지
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• 제28권3호
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• pp.367-373
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• 2011

This research is a basic researching process for producing solid fuel that mixing paper sludge and Heat Transfer Medium Oil. Under the presence of Heat Transfer Medium Oil, paper sludge is heated and dried with home appliance microwave for comparing drying efficiency and energy efficiency of different types of drying method. As a result, Heat Transfer Medium Oil and paper mixing case of drying method, OMD, is the most efficient way to shorten the time for evaporating moisture in the paper sludge. In addition, heat transfer effect and density is increased with adding Heat Transfer Medium Oil by microwave. Future more, OMD's energy cost for evaporating whole moisture is 78% cheaper than MD. Also, OMD process shows the best energy efficiency with comparing other process. Evaporation rate of paper sludge evaporation process with microwave is 11.66% increased by adding Heat Transfer Medium Oil 150g. Preheating Heat Transfer Medium Oil or improving different ways injecting Heat Transfer Medium Oil is a good way to increase a rate of initiative moisture evaporation process.

• Tribology and Lubricants
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• 제11권1호
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• pp.50-57
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• 1995

When engine oil is used under severe running condition, the Lubricational characteristics is very important. I have studied the Lubricational characteristics with Compound Additives of engine oil for the Falex wear test machine. Adding detergent (Ca-phenate) to engine oil, the seizure is more improved than in case of non-adding, and adding Zn-DTP (Zinc dialkyl dithio phosphate), the extreme pressure property is excellent at the high load. But when the PTFE (Polytetra Fluoro Ethylene) and MoS$_{2}$ (Molybdenum disulfide) are added, the temperature characteristics and the anti-wear property become excellent because the stability can be maintained in a high temperature. The result are as follows, it can be improved that when the compound of the Ca-phenate and Zn-DTP, MoS$_{2}$, PTFE, etc. was added to engine oil, the lubrication characteristics become better. It is argued that it is improved because of excellence of the anti-wear, the extreame pressure properties and the heat stability.

• 해양환경안전학회:학술대회논문집
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• 해양환경안전학회 2006년도 추계학술발표회
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• pp.169-174
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• 2006

모든 원유 (crude oil)와 제품유 (petroleum product)는 서로 구별되는 탄화수소특성을 가지고 있다. 원유의 경우 산지별로 고유한 특성을 지니고 있으며, 제품유의 경우 같은 유종이라 할지라도 그 원료가 되는 원유의 특성, 생산공정, 생산시기 등에서 차이점이 발생한다. 즉, 생산시기가 동일하다 할지라도 선박의 연료탱크내에 남아있는 잔류유와의 혼합 동에 의해 구별되는 특징을 가지게 되며 이러한 특성을 이용한 기법을 유지문기법(oil fingerprint method) 이라 한다. 본 연구에서는 최근 새로운 유지문기법으로 활용 가능성이 대두되고 있는 2 차원 가스크로마토그래프 (Comprehensive Two Dimensional Gas Chromatography)를 이용하여 기존의 가스크로마토그래프 (GC)와 가스크로마토그래프 질량분석기 (GC/MS) 와의 분석방법 비교 등을 통해 유지문 분석기법의 실효성에 대해서 논하고자 한다.

• Journal of Nutrition and Health
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• 제16권1호
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• pp.10-20
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• 1983

In order to establish tissue lipid status in animal on feeding of various dietary fat and oils, each group of rats was fed a semisynthetic diet containing 10%(w/w) mackerel oil (MO), eel oil (EO), soybean oil (SO), rapeseed oil (RO) or beef tallow (BT) for 1, 2 and 4 weeks, After each feeding period, levels of cholesterol, triglyceride and phospholipid were measured in serum. Fatty acid ${\leftarrow}$ composition was also investigated in serum and tissue lipids. Levels of total serum cholesterol were lower but HDL-cholesterol were higher in fish oil groups, which resulted in significantly higher ratio of HDL to total cholesterol in the fish oil groups. Fish oil groups, in general, also had lower levels of serum triglyceride and phospholipid than other groups, but S0 group maintained as low phospholipid levrl as fish oil groups. Fatty acid composition of dietary fat was reflected in all the tissues investigated but with varying degrees. Very long chain fatty acids, specific components exclusively found in fish oils were most well reflected in liver and relatively well in serum, whereas linoleic acid and erucic acid of SO and RO in the diet were better shown up in heart and adipose tissue. It attracted a particular attention that major proportions of long chain monoenoic acids $(C_{22:1})$ occurring both in MO and RO were detected separately in liver and heart plus adipose tissue, the result of which strongly indicates that there is a significant difference in metabolism between isomers $(C_{22:1}\;w\;11\;and\;C_{22:1}\;w\;9,\;respectively)$. It is suggested from this study that differences in lipid status as well as in the levels of serum lipids result from uniqueness in metabolism of each different fatty acid and give rise to distinguishable change in serum lipoprotein pattern, followed by diet with different fat sources.

• 대한약침학회지
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• 제25권2호
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• pp.121-129
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• 2022

Objectives: The chemical composition of cactus pear seed oil (Opuntia ficus-indica [L.] Mill.) was analyzed in terms of its fatty acid composition, tocopherol content, phenolic identification, and the oil's phenolic-rich fraction antioxidant power was determined. Methods: Fatty acid profiling was performed by gas chromatography coupled to an FI detector. Tocopherols and phenolic compounds were analyzed by LC-FLD/UV, and the oil's phenolic-rich fraction antioxidant power was determined by phosphomolybdenum, DPPH assay and β-carotene bleaching test. Results: Fatty acid composition was marked by a high unsaturation level (83.22 ± 0.34%). The predominant fatty acid was linoleic acid (66.79 ± 0.78%), followed by oleic acid (15.16 ± 0.42%) and palmitic acid (12.70 ± 0.03%). The main tocopherol was γ-tocopherol (172.59 ± 7.59 mg/kg. In addition, Tyrosol, vanillic acid, vanillin, ferulic acid, pinoresinol, and cinnamic acid were identified as phenolic compounds in the analyzed seed oil. Moreover, the oil's phenolics-rich fraction showed a significant total antioxidant activity, scavenged DPPH up to 97.85%, and effectively protected β-carotene against bleaching (97.56%). Conclusion: The results support the potential use of cactus pear seed oil as a functional food.

• 한국식품과학회지
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• 제54권3호
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• pp.320-326
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• 2022

본 연구에서 제조된 쿠키의 품질특성과 항산화 활성에 미치는 영향을 알아보기 위하여 버터, 미강유, 카놀라유, 코코넛오일과 기타 식물성 재료들을 이용하여 렌틸콩 비건 쿠키를 제조하였다. 이를 이용해 반죽의 pH, 밀도, 쿠키의 퍼짐성, 굽기 손실률, 색도, 수분함량, 경도, 항산화 활성을 측정하였다. 퍼짐성은 모든 종류의 유지에서 유지함량이 증가할수록 증가하는 경향을 보였다. 굽기 손실률 측정 결과 네 종류 유지 모두 유지첨가량이 늘수록 굽기 손실률이 증가하는 경향을 보였다. 수분함량은 네 가지 유지에서 모두 유지함량이 증가할수록 증가하였으며(p<0.05) 미강유 30 g 첨가군의 수분함량이 가장 높은 값을 나타냈다. 경도는 쿠키의 수분함량과 반비례하는 경향을 보였으며, 유지의 함량이 증가할수록 경도가 유의적으로 감소하였다(p<0.05). 반죽과 쿠키의 품질특성을 측정한 결과로 보았을 때 카놀라유, 코코넛오일, 미강유 모두 버터를 대체하기에 적합한 유지임을 알 수 있었다. 하지만, 미강유를 첨가한 쿠키에서 유지의 함량이 증가할수록 radical 소거능이 증가하는 경향을 나타냈다(p<0.05). 따라서, 비건 렌틸콩 쿠키 제조 시 버터를 대체할 식물성 유지로 미강유의 활용이 가장 적합하다고 판단된다. 앞으로 미강유를 활용한 비건 렌틸콩 쿠키의 품질 및 항산화능 향상을 기대할 수 있을 것으로 사료된다.

• KSTLE International Journal
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• 제7권2호
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• pp.35-44
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• 2006

Turbocharger bearings are under the circumstance of high temperature, moreover rotated at high speed. It is necessary to be designed overcoming the high temperature. So the type of oil inlet port, the inlet oil temperature and the sort of engine oil should be designed, controlled and selected carefully in order to reduce the bearing inside temperature. In this study, the influence of aerated oil on a high-speed journal bearing is also examined by using the classical thermohydrodynamic lubrication theory coupled with analytical models for viscosity and density of air-oil mixture in fluid-film bearing. Convection to the walls and mixing with supply oil and re-circulating oil are considered. The considered parameters for the study of bubbly lubrication are oil inlet port's type, oil aeration level and shaft speed. It is found that the type of oil inlet ports and shaft speed play important roles in determining the temperature and pressure, then the friction and load of journal bearing at high speed operation. Also, the results show that, under extremely high shaft speed, the high shear effects on aerated oil and the high temperature effects are canceled out each other. So, the bearing load and friction show almost no difference between the aerated oil and pure oil.

• Asian-Australasian Journal of Animal Sciences
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• 제8권4호
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• pp.369-373
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• 1995

A study was conducted to determine the effects of varying palm oil levels (0 to 8%) in the diets on the performance of broilers under the warm humid tropical environment. Increasing palm oil levels resulted in corresponding rise in the dietary energy concentrations, and broilers fed on higher energy diets improved feed and energy consumption, daily weight gain and feed conversion ratio. Total carcass fat content was found to increase at higher levels of palm oil inclusions.