• Journal of Advanced Marine Engineering and Technology
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• v.37 no.1
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• pp.53-58
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• 2013

In order to judge that non-esterified soybean oil could be used on diesel engine with electronic control of fuel injection system, The test of combustion performance using only gas oil, gas oil blended with esterified bio-diesel oil 5% and non-esterified soybean oil 5% were carried out. It is noticed that most performances of gas oil blended with esterified bio-diesel oil 5% and non-esterified 5% have similar characteristics but non-esterified bio-diesel oil 5% emitted smaller NOx, resulting from fuel NO.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.2
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• pp.143-150
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• 2007

Ring and cylinder bore wear may not be a problem in most current automotive engines. However, a small change in ring face and cylinder bore diameter can significantly affect the lubrication characteristics and ring axial motion. This in turn can cause to change inter-ring pressure, blow-by and oil consumption in an engine. Therefore, by predicting the wear of piston ring face and cylinder bore altogether, the changed ring end gap and the changed volume of gas reservoir can be calculated. Then the excessive oil consumption can be predicted. Here, the oil amount through top ring gap into combustion chamber is estimated as engine oil consumption. Furthermore, the wear theories of ring and cylinder bore are included. The changed oil consumption caused by the new end gap and the new volume of oil reservoir around second land, can be calculated at some engine running interval. Meanwhile, the wear amount and oil consumption occurred during engine durability cycle are compared with the calculated values. The wear data of rings and cylinder bore are obtained from three engines after engine durability test. The calculated wear data of each part are turn out to be around the band of averaged test values or a little below. It is shown that the important factor regarding oil consumption increasement is the wear of ring face.

• Fisheries and Aquatic Sciences
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• v.15 no.4
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• pp.275-281
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• 2012

Yellow croaker Larimichthys polyactis muscle oil was extracted using an environmental friendly solvent, supercritical carbon dioxide (SC-$CO_2$), in a semi-batch flow extraction process. SC-$CO_2$ was applied at temperature $35^{\circ}C$ to $45^{\circ}C$ and $150^{\circ}C$ to $250^{\circ}C$ bar of pressure. The flow rate of $CO_2$ (27.79 g/min) was constant throughout the entire 1.5 h extraction period. The oil extraction yield was influenced by the physical properties of SC-$CO_2$ at different temperatures and pressures. The extracted oil was analyzed by gas chromatography to determine the fatty acid composition. According to our results, the SC-$CO_2$ extracted oil was high in eicosapentaenoic acid and docosahexaenoic acid. In addition, the SC-$CO_2$ extracted oil showed greater stability than n-hexane extracted oil based on the peroxide value and acid value. Thus, the quality of yellow croaker oil obtained by SC-$CO_2$ extraction was slightly higher than that of oil obtained by n-hexane extraction.

• Korean journal of food and cookery science
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• v.12 no.1
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• pp.99-107
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• 1996

The cooking characteristics of Hicook with lecithin and GMS as emulsifier were examined for effect on the reduction of oil levels in fried foods. Hicook and soybean oil were used in stir-frying and pan-frying, and in case of Hicook the weight of oil absorbed and spattered during cooking were significantly lower than in case of soybean oil. Next this study attempt to standardize the recipe for preparation of selected Korean foods, especially in regards of the amount of oil used during cooking. The foods studied were all used frequently in Korea, they inculded stir-fried vegetables, stir-fried rice, and pan-fried fish and soybean curd. The results showed that Hicook, even in a half amount, made it possible cooking food with good properties, and calorie content of cooked foods could be lowered considerably. The trained panelists evaluated sensory characteristics of foods, flavor, appearance, and overall acceptability. Sensory qualities of food prepared with Hicook were highly acceptable, and rated better than controls in flavor and overall acceptability. But because stir-fried food was accepted greasy and oily in customarily, the appearance was rated lower than comtrol. In summary, application of hicook offers means of lowering fat levels while keeping sensory quality good. The emulsifier in Hicook is responsible for reduction of oil content and improvement of quality of fried foods.

• Korean journal of food and cookery science
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• v.19 no.6
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• pp.729-736
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• 2003

This study was performed to improve the quality and extend the shelf life of Yukwa and Salyeotgangjung, traditional Korean cookies, by using fine hot salt instead of oil as the popping medium. Yukwa and Salyeotgangjung were popped with fine salt, and the size, sensory evaluation, color values and textural properties were then compared with those popped in oil. The results showed that the Yukwa base with salt was popped the most at 140C and the rice was popped at 240C. The Yukwa base in salts was smaller in size and larger in density than in oil but the popped rice in salts had a similar size and a smaller density than that popped in oil. In the sensory test, the Yukwa base and popped rice expanded in the salts were preferred to those popped in oil but there was little difference in only popped rice. In terms of color, there was a difference between those popped in salt and in oil. In terms of texture, only popped rice expanded in the salts was harder than in oil, and the Yukwa popped in oil was more cohesive than in the salts. In brittleness, there were no differences between in salt and in oil.

• Korean Journal of Agricultural Science
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• v.47 no.1
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• pp.29-41
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• 2020

Biodiesel is a clean energy resource that can replace diesel as fuel, which can be used without any structural changes to the engine. Vegetable oil accounts for 95 percent of the raw materials used to produce biodiesel. Thus, many problems can arise, such as rising prices of food resources and an imbalance between supply and demand. Most of the previous studies using waste cooking oil used waste cooking oil from a single material. However, the waste cooking oil that is actually collected is a mixture of various types of waste cooking oil. Therefore, in this study, biodiesel produced with mixed waste cooking oil was supplied to an agricultural single-cylinder diesel engine to assess its potential as an alternative fuel. Based on the results, the brake specific fuel consumption (BSFC) increased compared to diesel, and the axis power decreased to between 70 and 99% compared to the diesel. For emissions, NO_x and CO₂ were increased, but CO and HC were decreased by up to 1 to 7% and 16 to 48%, respectively, compared to diesel. The emission characteristics of the mixed waste cooking oil biodiesel used in this study were shown to be similar to those of conventional vegetable biodiesel, confirming its potential as a fuel for mixed waste cooking oil biodiesel.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.6 no.4
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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.

• Proceedings of the SAREK Conference
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• 2009.06a
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• pp.893-898
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• 2009

The quantity of discharged oil from a compressor is one of the most important issues for proper operation of refrigeration system. If the oil is increased in the system not only pressure drop is increased in other components, such as evaporator and gas cooler but also heat transfer coefficient in the heat exchangers is decreased. In addition, the lack of oil in the compressor may cause a critical of the system failure. In this study, one stage single rotary compressor is used for measuring oil circulation ratio(OCR). Carbon dioxide and PAG oil are used as refrigerant and lubricant. Using a U-tube densimeter, mixture density is measured. Characteristics of oil circulation ratio have been investigated for $CO_2$ rotary compressor in the range of operation frequency 45 Hz to 63 Hz and the suction temperature range of $0^{\circ}C$ to $15^{\circ}C$. The results obtained indicate that the oil circulation ratio is increased as the suction temperature or compressor operating frequency is increased.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.21 no.10
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• pp.559-563
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• 2009

Performance of refrigerant oil at the thrust-bearing and at the journal-bearing of a scroll compressor is a significant factor. This paper presents the friction and anti-wear characteristics of nano oil with a mixture of a refrigerant oil and carbon nano particles. The characteristics of friction and anti-wear using nano-oil is evaluated using the disk on disk tester for measuring friction surface temperature and the coefficient of friction. The average friction coefficient of nano-oil was reduced by 60% compared to raw oil under 600 N and 1,000 rpm. It is believed that the interaction of nano particles between surfaces can be improved the lubrication in the friction surfaces. Worn surfaces of frictional specimen were also investigated by the optical and atomic force microscopy. Conclusively, it is expected that wear and friction coefficient of compressor can be reduced by alignment applying nano-oil as refrigerant oil.

• Journal of Food Hygiene and Safety
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• v.9 no.4
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• pp.213-220
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• 1994

Customary usage of oil at homes and rancidity of edible soybean oil by cooking frequency at homes and mass meal services were investigated. 80% of house wives bought the cooking oil by 1.8ι unit container and 70% of them read either the manufactured date or explanatory note for use. 85% of house wives kept oil in the storage case under sink or in the pantry chest, and 80% of oils were used once or twice and 20% used three times for cooking. Acid value(AV), iodine value(IV), peroxide value(POV), carbonyl value(CoV) and thiobarbituric acid value(TBAV) of fresh soybean oil were lower than standard level. In the rancidity by cooking frequency, the acid value, peroxide value, carbonyl value and thiobarbituric acid value increased significantly when oil was used once and iodine value decreased significantly when used once and twice at both mass meal services and homes. The level of the acid value, iodine value, carbonyl value and thiobarbituric acid value of oil used at mass meal services did not show significant difference from those of oil used at homes. But, the peroxide value of oil used thrice at mass meal services was significantly higher than those of homes.