• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.4
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• pp.36-41
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• 2004

The purpose of this paper is analyzing the oil film pressure distribution and the minimum oil film thickness for a connecting rod bearing using an A VL's EXCITE program. It is very important to understand optimized oil supplying holes and oil groove dimensions for supporting sufficiently inertia forces and gas pressures from the combustion chamber for a Diesel engine. The computed results indicate that the optimized oil groove width of a bearing and oil hole of a journal are recommended for high performance of a connecting rod bearing at the elastohydrodynamic lubrication zone. These results as design parameters are very useful data for a bearing designer as a firm reference of an automotive engine.

• Transactions of the Korean Society of Automotive Engineers
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• v.12 no.4
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• pp.34-34
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• 2004

The purpose of this paper is analyzing the oil film pressure distribution and the minimum oil film thickness for a connecting rod bearing using an A VL′s EXCITE program. It is very important to understand optimized oil supplying holes and oil groove dimensions for supporting sufficiently inertia forces and gas pressures from the combustion chamber for a Diesel engine. The computed results indicate that the optimized oil groove width of a bearing and oil hole of a journal are recommended for high performance of a connecting rod bearing at the elastohydrodynamic lubrication zone. These results as design parameters are very useful data for a bearing designer as a firm reference of an automotive engine.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.6
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• pp.541-549
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• 2000

The present study experimentally investigated the effect of refrigeration oil on the condensation heat transfer for R-407C and R-22 in a microfin tube with a U-bend. POE oil ($74.1\;\textrm{mm}^2/s,\;40^{\circ}C$,) and mineral oil $62.5\;\textrm{mm}^2/s,\;40^{\circ}C$,) were used for R-407C and R-22 respectively Experimental parameters were an oil concentration from 0 to 5%, a mass flux from 100 to $400kg/m^{2}s sand an inlet quality from 0.5 to 0.9. The enhancement factors for both R-22 and R-407C refrigerants at the first straight section decreased continuously as the oil concentration increased. They decreased rapidly as the mass flux decreased and the inlet quality increased. The heat transfer coefficients in the U-bend showed the maximum at the $90^{\circ}$/TEX> position. The heat transfer coefficients at the second straight section within the dimensionless length of 48 were larger by a maximum of 33% than the average heat transfer coefficient at the first straight section.

• Tribology and Lubricants
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• v.38 no.3
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• pp.109-114
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• 2022

This paper reports the development of an oil flushing system combined with a microbubble generator. Oil flushing plays a crucial role in regulating the lubricant's performance during the lubricant replacement process. Moreover, harmful contaminants, such as sludge, wear particles, and rust, from piping systems or lubrication system can be removed by oil flushing. Oil flushing aims to increase the system's efficiency using a dedicated flushing oil, increasing of the supply pressure and generating a vortex. In addition, it helps the mechanical system or equipment achieve peak performance and reduces the potential for premature failure. However, the contaminant-removal applications of existing oil flushing system are limited. In this research, we aim to improve the performance of oil flushing system by incorporating a microbubble generator, which uses the venture effect to generate microbubbles and mixes them with lubricant. The microbubbles in the blended lubricant remove contaminants from the lubrication system more effectively. Structural mechanics and fluid dynamics are analyzed through fluid-structure interaction (FSI) analysis, and the numerical analysis results are used for the designing the system. The magnitude of the maximum stress is investigated based on the pressure results obtained by the CFD analysis; through the CFD analysis, the mixing ratio of air (bubble) and lubricant is evaluated using the volume of fluid (VOF) model according to the working conditions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.43 no.12
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• pp.1865-1870
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• 2014

To synthesize ${\omega}$-3 and ${\omega}$-6 balanced polyunsaturated fatty acid (PUFA) oil mixture, flaxseed oil and sesame oil were mixed and their anti-oxidative and sensory characteristics analyzed. For the fatty acid composition analysis results, the ${\omega}$-3 and ${\omega}$-6 PUFA ratios of the F20S80 oil mixture (flaxseed oil 20% and sesame oil 80% oil mixture) and F10S90 (flaxseed oil 10% and sesame oil 90% oil mixture) were represented as 1 to 10 and 1 to 5 ratio for ${\omega}$-3 and ${\omega}$-6 PUFA content from 4.4% to 42.1% and 8.9% to 39.7%, respectively. Since these were within 1:4~1:10 for healthy functional ${\omega}$-3 and ${\omega}$-6 balanced PUFA oil mixtures, these oil mixtures were healthy functional oil mixtures. To analyze anti-oxidative effects, acid values were analyzed. Samples were stored at room temperature, 70% relative humidity (RH) and $45^{\circ}C$, and 70% RH for 16 weeks. The acid value between F10S90 and S100 stored at $45^{\circ}C$ and 70% RH for 16 weeks were not statistically significant. The sensory characteristics such as oxidative odor and sesame odor and taste were not statistically significant among F20S80, F10S90, and sesame S100. Sensory characteristics between F10S90 and S100 stored at $45^{\circ}C$ and 70% RH for 16 weeks were not statistically significant. In conclusion, the sensory and oxidative characteristics of F10S90 were similar to those of S100. Therefore, F10S90 oil mixture should be used as a ${\omega}$-3 and ${\omega}$-6 balanced PUFA healthy functional oil mixture with high anti-oxidative effects.

• Asian-Australasian Journal of Animal Sciences
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• v.17 no.6
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• pp.857-862
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• 2004

The present study was carried out to examine the changes in functional properties of cholesterol-removed compound whipping cream made by $\beta$-CD treated cream and palm oil. Six different ratios of cream to palm oil (10:0 as control, 9:1, 8:2, 7:3, 6:4, and 5:5, v/v) were tested. The overrun percentage increased with an increased amount of palm oil. When the ratio of cream to palm oil was 10:0 (control), the overrun was 130%, which was significantly lower than other ratios reached to 150%. Foam instability was measured as 3.1 ml defoamed cream in control, however, the value of foam instability decreased with an increase of palm oil addition. The TBA value of cholesterol-removed compound whipping cream increased from 0.08 to 0.13 with no addition of palm oil during 4 wk storage. When the ratio of cream to palm oil was 5:5, TBA value increased dramatically at 3 wk and thereafter. Among sensory characteristics, texture value increased with higher amount of palm oil, however, flavor and overall preferences were opposite. Above results indicated that partial substitution of palm oil in manufacture of cholesterol-removed compound whipping cream resulted in a stable foam development with little adverse effect on flavor and lipid oxidation during storage. The present study showed a possible application in manufacture of cholesterol-removed compound whipping cream, which may be effective in other foods.

• Food Engineering Progress
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• v.13 no.4
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• pp.275-281
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• 2009

Sesame oils are partially mixed with other vegetable oils due to high price in a Korean market. To find out authentic sesame oil, a mass spectrometer-based electronic nose (MS-based E-nose) was used. Sesame oil (Se) was blended with soybean oil (So) or corn oil (Co) at the ratio (Se:So, Se:Co) of 97:3, 94:6, 91:9, 88:12 and 85:15, respectively. Intensities of each fragment from sesame oil by MS-based E-nose were completely different from those of soybean oil or corn oil. The obtained results were used for discriminant function analysis (DFA). Volatile organic components (VOC) of soybean oil or corn oil were similar to those of fresh air and DFA plot indicated a significant separation of pure sesame oil and pure other oil. The group of the mixed oil was seperated with that of sesame oil in DFA plot and the added amount of soybean oil to sesame oil was correlated with discriminant function first score (DF1). MS based E-nose system could be used as an efficient method to investigate the purity of sesame oil.

• Tribology and Lubricants
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• v.25 no.1
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• pp.1-6
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• 2009

In this paper, the minimum oil film thickness and the maximum oil film pressure of engine bearings have been analyzed by using the elastohydrodynamic theory and Taguchi's design method as functions of the oil groove width, oil hole diameter, oil hole position, and oil supply pressure. The optimized design of the engine bearing f3r an automotive Diesel engine is very important for supporting a load-carrying capacity due to gas pres-sures from the engine combustion chamber and inertia forces of the piston. The optimized design data of engine bearings indicated that the optimized oil groove width and an oil diameter of a engine bearing are 8mm at the speed of 2,000 rpm for a given 4-cylinder Diesel engine. Thus, the oil groove oil groove and an oil hole for high performances of an engine bearing may be considered as major design parameters compared to other design factors, which are strongly related to the minimum oil film thickness and the maximum oil pressure distribution of the engine oil.

• Journal of Korean society of Dental Hygiene
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• v.20 no.6
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• pp.973-980
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• 2020

Objectives: This study was to analyz the effects of comparative evaluation of the effects of oil pulling on periodontal indices. Methods: A total subjects were 38; control group (19 subjects) and experimental group (19 subjects). In the experimental group, coconut oil was provided and rinsed the mouth for about 10 minutes once a day. We evaluated possession rate of pocket depth (≥4 mm), possession rate of bleeding on exploring and possession rate of gingival recession (≥1 mm). Results: The possession rate of pocket depth (≥4 mm), bleeding on exploring and gingival recession (≥1 mm) significant difference in interaction between the group and measurement time. Conclusions: The findings of this study indicate that dental hygiene process and oil pulling specialists in care of periodontal diseases were effective mediation.

• Journal of Life Science
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• v.16 no.6
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• pp.949-954
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• 2006

Soybean [Glycine max (L.) Merr.] is an important crop, accounting for 48% of the world market in oil crops. Improvement of the quality and quantity of soybean seed constituents is one of the most important objectives in soybean breeding. Protein content and seed size are important properties to determine the quality of tofu and soy sprouts respectively. The objective of this study was to identify quantitative trait loci (QTLs) that control seed weight, protein and oil content in soybean. The 117 $F_{2:10}$ recombinant inbred lines (RlL) developed from a cross of 'Keunolkong' and 'Shinpaldalkong' were used. Narrow-sense heritability estimates based on a plot mean on seed weight, protein and oil content were 0.8, 0.78 and 0.71, respectively. Four independent QTLs for seed weight were identified from linkage group (LG) F, I and K. Five QTL for protein content were located on LG D1b, E, H, I and L. Oil content was related with six QTLs located on LG D1b, E, G, I, J and N. Protein and oil content have three common QTLs on LG D1b, E and I. Thus, we identified major loci improving soybean seed quality.