• Tribology and Lubricants
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• 제26권4호
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• pp.209-218
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• 2010

In this study, the effect of dimensions and location of oil grooves on the static performance of a cylindrical journal bearing is analyzed numerically. Axial length, circumferential length and location of oil grooves are considered as parameters. Cavitation occurs within the diverging region of a journal bearing. The distribution of cavitation region where cavitation occurs varies with dimensions and location of oil grooves and affects the performance of a journal bearing. Elrod's cavitation algorithm which implements JFO boundary conditions based on the principle of mass conservation at the interfaces between cavitation and full film region is adopted in order to consider the effect of cavitation. The result shows that parameters, especially location of oil grooves have a great effect on the static performance of a journal bearing.

• 대한가정학회지
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• 제19권1호
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• pp.33-37
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• 1981

The accelerating effect of sunlight on the rancidity of soybean oil and the efficacies of several anti-oxidants were measured. The result is as follows: 1. The ac야 value and peroxide value of soybean oil were 0.16 and 1, 72 respectively. 2. the peroxide value of soybean oil which was exposed to sunlight nine hours a day for six days was 134.3: 21 times of that which was not exposed to sunlight. 3. The peroxide value of the soybean oil with 0.02~0.06% BHA decreased a little, but not significantly. 4. The anti-rancidity effect of BHT was a little stronger than BHA. 5. The anti-rancidity effect of ascorbic acid alone was negligible. 6 The peroxide value of soybean oil with an anti-oxidant which comprised ascorbic acid, BHA and BHT decreased to one third of that which was not treated with anti-oxidant.

• Journal of Nutrition and Health
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• 제22권6호
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• pp.447-456
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• 1989

This study was performed to investigate nutritional effect and the utilization possibility of rapeseed oil which could replace the imported edible oils and oil crops. The proximate compositions of a recommendable cultivar(Mokpo Dangyo 19) and a native kind(Asahi) and the characteristics of these rapeseed oils were analyzed. The animal experiment of these rapeseed oils was carried out during 8 weeks of growing periods after weanling. Forty male weanling Sprague-Dawley rats were randomly assigned to 3 diet groups of Dangyo 19 oil, Asahi oil and commercial Soybean oil. Mokpo Dangyo 19 variety contained more lipids than Asahi variety by 8% and there was no difference in physiochemical characteristics between Dangyo 19 oil and Asahi oil except that erucic acid was contained little in Dangyo 19 oil but 50% in Asahi oil. Body weight gain, FER(Feed efficiency ratio) and PER(Protein efficiency ratio) of rats fed Dangyo 19 oil were higher than those of rats fed Asahi oil and organ weights such as liver, kidney and epididymal fat pads weights of rats fed Dangyo 19 oil were significantly higher(P<0.05) thanthose of rats fed Asahi oil. the apparent digistibility of total diet and total lipid were higher in rats fed the diets containing Dangyo 19 oil than Asahi oil. The content of total lipid in heart in heart were not significantly different with dietary oil kinds. The content of total lipid in liver increased with age in all rapeseed oil groups.

• 한국식품조리과학회지
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• 제28권4호
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• pp.443-450
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• 2012

This study was investigated the effect of an oil-water fryer on quality properties of deep frying oil used for chicken. The acid and conjugated dienoic acid values of frying oil using an oil-water fryer were lower than those using a deep fat fryer, whereas the iodine value of frying oil using an oil-water fryer was higher than that using a deep fat fryer. The peroxide values of frying oil did not increase with frying number. Frying oil with an oil-water fryer had lower palmitic acid, stearic acid and oleic acid, and higher linoleic and linolenic acid contents than those with a deep fat fryer. The contents of trans-fatty acids in frying oil using a deep fat fryer and oil-water fryer after frying 110 chickens were 0.75% and 0.47%, respectively. The benzopyrene contents of frying oil using a deep fat fryer and an oil-water fryer after frying 110 chickens were 2.20 and $1.61{\mu}g/kg$, respectively.

• 한국식품영양과학회지
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• 제24권3호
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• pp.371-377
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• 1995

The effect of ${\alpha}$-tocopherol and ${\beta}$-carotene supplementation on reducing the oxidative damag in the liver of rats were studied. Forth-five male Sprague Dawley aged 4 weeks were randomly assigned to 9 groups of five for the 12 weeks of the study. Nine groups, sardine oil, sardine oil＋Vt E, sardine oil＋${\beta}$-carotene, soybean oil, soybean oil＋Vt E, soybean oil＋${\beta}$-carotene, lard, lard＋Vt E, lard＋${\beta}$-carotene group, were prepared. Sardine oil, soybean oil, or lard was used for dietary fat and 200% of ${\alpha}$ -tocopherol or 150% of ${\beta}$-carotene was supplemented to each diet. Each diet supplied 65% of total energy as carbohydrate, 15% as protein, and 20% as lipid. The MDA value and protein carbonyl contents of sardine oil group were significantly different(p<0.05) to those of other fat groups indicating that the most severe lipid oxidation occurred in the group fed diet containing highly polyunsaturated fatty acid. When ${\alpha}$-tocopherol or ${\beta}$ -carotene was supplemented to the sardine oil diet, MDA value(-35%, -15%, respectively) and protein carbonyl content(-44%, -32%, respectively) decreased significantly(p<0.05). Cu, Zn-superoxide dismutase(SOD) and catalase activities of three different sardine oil groups with or without antioxidants were lower than those of soybean oil or lard group. The reducing effect of ${\alpha}$-tocopherol on oxidative damage in sardine oil group supplemented with ${\alpha}$-tocopherol was noticeable(p<0.05). However the adverse effect of ${\beta}$-carotene was observed. SOD and catalase activities of ${\beta}$-carotene supplemented groups were that the lowest among the same fat groups, but the differences were not statistically significant. The possible cause of decreased enzyme activity seemed to be related to the vitamin A(Vt A) toxicity in the liver where retinol converted from dietary ${\beta}$-carotene in the intestinal mucosa was stored.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.24-27
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• 2002

The environmental problems by using coolant demanded the new cooling methods. As one of them, the studies on the finding with compressed cold air and oil mist have been done. The cooling method using compressed cold air was effective through going down the temperature of compressed air supplied below $-25^{\circ}$ and increasing the amount of compressed cold air, but had not enough cooling effect due to the low performance of lubrication. Therefore, the cooling methods using oil mist newly were suggested. This method can satisfy both cooling effect and lubrication with only small amount of coolant, also have the benefit in the point of decreasing the environmental pollution. This paper focused on analyzing the grinding characteristics of the cooling method using oil mist. The grinding test according to compressed cold air, oil mist spray pressure and oil mist supply direction were done.

• 한국응용과학기술학회지
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• 제22권3호
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• pp.241-249
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• 2005

This experiment extracted the natural green-tea using ethanol and obtained the refined oil component after filterated green-tea extract. This study tested the antimicrobial effect as characteristics experiment, and analyzed refined oil component with pH-meter and GC/MS. In the result of this experiment, it obtained the next conclusions. In the first result of extraction experiment, it could know that extraction ratio of refined oil component appeared about 9.0%. In the second result of characteristics experiment, it could certificate that in case of increasing the refined oil component in concentration of 100ppm and above, and according to passage of cultivation time, the number of S-aureus and E-coli in microbe decreased less and less. But in case of blank test not adding the refined oil component, the number of microbe increased more and more. In these phenomena, it could certificate that refined oil component of green-tea appeared antimicrobial effect against microbe. In the third result of instrumental analysis, refined oil component of green-tea appeared about 7.6 in 1% distilled water solution with pH-meter, and the aromatic components of benzene, bonyl acetate, campene, ${\alpha},{\beta},{\gamma}$-pinnene etcs from refined oil component of green-tea was detected with GC/MS.

• Journal of Nutrition and Health
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• 제27권6호
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• pp.552-562
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• 1994

The study was designed to observe the effect of different dietary fats on the incidence of colorectal tumor and in vivo cell proliferation in colon carcinogenesis. Male Sprague Dawley rats were intrarectally infused with chemical carcinogen(methylnitrosourea, MNU) and fed 16%(w/w) fat diet containing one of dietary fats(beef tallow, corn oil, perilla oil) for 30 weeks. To measure in vivo cell proliferation, the incorporation of 5-bromo-2-deoxyuridine(BrdU) into DNA was localized using the monoclonal anti-BrdU antibody. Large number of tumors were found in the distal colon and tumor incidence was increased in the order of perilla oil(57.7%)$\alpha$-linolenic acid rich in perilla oil could have a protective effect against colon cancer compared to saturated fatty acid or n-6 linoleic acid.

• 한국의류학회지
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• 제47권1호
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• pp.52-72
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• 2023

This study examined the effect of Jojoba oil on the protection of virgin black hair and hair damaged by bleaching. Both hair types were treated for 35 days with 100% Jojoba oil or one of two types of hair conditioner, one formulated with 3% of Jojoba oil and the other formulated without Jojoba oil. The effect of protection was examined in terms of the change in the color, tensile stress, weight, and amount of protein leak compared to untreated black hair or bleached hair. The composition of fatty acids in the Jojoba oil was analyzed using the Gas chromatography mass spectrometry. The differences among the three treatments were statistically tested by one-way analysis of variance test and the Duncan post-hoc test at α = .05. The main fatty acid contained in the Jojoba oil was 11-eicosenoic acid (75.14%). Based on the statistical test it was found that 100% Jojoba oil was the most effective in increasing the tensile stress of black hair and the weight of bleached hair after 35 days of treatment.

• Journal of Nutrition and Health
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• 제34권8호
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• pp.843-849
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• 2001

This study was performed to investigate the effect of n-3 fatty acids and dietary protein levels on renal function. Fifteen-month old male Sprague-Dawley rats were divided into 4 diet groups. Two-month old rats were used as a control group. The experimental diets contained either a% or 25% casein and lipid levels of the diets were 20% by weight. For the control group, the lipid was composed of beef tallow and corn oil on a 1:1 basis, and fish oil was comprised 75% of the fat mixture for the fish oil group. Rats were fed the diets ad libitum for 8 weeks. GFR and urinary protein excretion were higher in high protein groups, while fish oil exhibited no effects. Renal medulla TXB$_2$and PGE$_2$ concentrations tended to be higher in high protein groups and lower in fish oil groups. Light microscopic examinations showed that glomerulosclerosis, tubular atrophy, tubular cast, interstitial inflammation and interstitial fibrosis fended to be higher in aged rats and in high protein groups and lower in fish oil groups. Serum levels of total lipid, triglyceride and total cholesterol were higher in aged rats and lower in fish oil groups while serum HDL-cholesterol level was higher in young rats and in fish oil groups. However, dietary protein level had no effect on serum lipid levels. Serum TBARS concentration was higher in aged rats and in fish oil groups. In conclusion, fish oil caused changes in serum lipid concentrations and eicosanoids metabolism. The effect of fish oil on renal function was less obvious than dietary protein. However, fish oil seemed to be effective in lessening deterioration of renal function due to aging and/or high protein diets through changes in lipid and eicosanoids metabolism.