• 한국자동차공학회논문집
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• 제2권4호
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• pp.9-17
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• 1994

Effect of Newtonian and non-Newtonian oils on minimum ol film thickness in engine journal bearing were investigated at various oil viscosities. The influence of oil viscosity and engine operating conditions on minimum oil film thickness of main bearing and con-rod bearing was examined. Minimum oil film thickness for Newtonian oils increased uniformly with kinematic viscosity. But the correlation between kinematic viscosity and minimum oil film thickness was very poor for non-Newtonian oils. According to the straight-line regression analysis for non-Newtonian oils, high temperature high shear viscosity at 1 $1{\times}10^6Sec^{-1}$, $150^{\circ}C$ increase the coefficient of determination from 0.41 to 0.77. Con-rod bearing showed better correlation between minimum oil film thickness and engine operating conditions than main bearing.

• 전기의세계
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• 제29권8호
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• pp.532-537
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• 1980

Effect of Argon and Sulfur hexafloride in the transformer oil are experimented under non-uniform A.C. electric field. The result has shown that the corona frequency and corona charge quantity in liquid dielectrics were varied with gas condition in the oil and affected by the additives. SF$_{6}$ that has the effects of pressure and electrical negative characteristic is the most effective. The corona is considered to be the breakdown of bubble produced by gas contained in the oil or by dissociated ion of the oil molecules.s.

• Journal of Nutrition and Health
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• 제25권7호
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• pp.555-568
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• 1992

This study was to compare the effects of dietary n-6 and n-3 fatty acids and fat unsaturation on plasma lipids and chemical composition of VLDL and LDL fraction and lipogenic enzymes activity in rat liver under the conditions providing 1) a similar amount of n-6, n-3 fatty acids(LA, ALA, EPA+DHA) in diets and 2) the various degree of fat unsaturation. Male Sprague-Dawley rats weighing 420g were treated for 6-n with six experimental diets providing 25% of energy as fat and which were different only in fatty acid composition. The fats used for a source of each fatty acid were beet tallow for saturated fatty acid corn oil for n-6 linoleic acid(LA) perilla oil for n-3 $\alpha$-linolenic acid(ALA) and fish oil n-3 eicosapentaenoic acid (EPA) and n-3 docosahexaenoic acid(DHA). Plasma cholesterol level was increased by corn oil to compare with beef tallow but was decreased by perilla oil or fish oil. Plasma TG level was significantly decreased by perilla oil or fish oil. Fish oil significantly reduced the level of HDL-Chol and the proportion of Chol in LDL fraction and that of TG in vVLDL fraction. Overall there was a singificant negative correlation between the level of each plasma lipid(Chol TG, VLDL-TG, LDL-C) and the degree of fat unsaturation. However this rerlationship is not always true when compared the hypolipidemic effect of each fatty acid at a similar level of fat unsaturation. There was a trend such taht glucose 6-P dehydrogenase 6-phosphogluconate dehydrogenase and malic enzyme activites were reduced by n-3 fatty acids. Perilla oil significantly increased the incorporation of c20:5 and c22:5 into liver tissue and fish oil suignificantly increased the incorporation of c20:5, c22:6 into liver tissue and the effect of long chain n-3 fatty acid incorporation was greater by fish oil. therefore the hypotriglyceridemic effect of n-3 fatty acid could be resulted from the interference of hepatic lipogenesis by long-chain n-3 fatty acids and the reduced proportion of TG in VLDL fraction and its effect was greater by n-3 EPA+DHA than n-3 ALA even though plasma Chol and TG levels were also influenced by the degree of dietary fat unsaturation.

• 한국식품영양학회지
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• 제13권6호
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• pp.534-538
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• 2000

대두유를 기초로 한 튀김유에 capsicum, butter flavor, 규소수지를 각각 0.20, 0.15%($\omega$/$\omega$) 및 10ppm 처리하여 가열안정성의 향상 및 육두향 약화에 효과가 있는 것으로 확인되었다. 즉, capsicum과 규소수지를 병행처리한 튀김유는 185$\pm$2$^{\circ}C$의 온도조건 하에서 3시간 동안 연속적으로 열처리할 경우 AV 및 SP가 각각 무처리군의 0.385, 22$0^{\circ}C$에 비하여 크게 향상된 0.301, 232$^{\circ}C$를 나타내었다. 이러한 효과는 capsicum의 항산화 효과와 함께 소포제의 일종인 규소수지의 작용에 따라 가열처리에 따른 튀김유의 표면적 팽창을 방지하여 유리지방산생성 및 연기발생을 억제한데 따른 효과인 것으로 판단되었다. 또한, 0.15%($\omega$/$\omega$)의 butter flavor처리에 따라 튀김유 및 튀김물에서 발생하는 육두향 및 기름타는 냄새를 막아주는 효과가 인정되어 새로운 형태의 튀김유 제품 생산이 가능할 것으로 기대되었다.

• Journal of Nutrition and Health
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• 제26권7호
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• pp.829-838
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• 1993

This study was designed to compare the effect of different dietary fats on the incidence of colorectal tumor, the level of plasma thromboxane B2(TXB2) and fatty acid profiles of platelet and colonic mucosal lipids in N - methyl - N - nitro - N - nitrosoguanidine(MNNG) - treated rats. Male Sprague Dawley rats, at 8 weeks old, were divided into 2 groups and infused intrarectally with saline(control group) or with 2mg MNNG(carcinogen-treated group) twice a week for 3 weeks. Each group was again divided into 4 groups and fed one of four diets(BT, CO, PO, FO) containing dietary fat at 9%(w/w) level for 37 weeks, Dietary fats were beef tallow(7.2%)+corn oil(1.8%) for BT, corn oil(9.0%) for CO, perilla oil(9.0%) for PO, fish oil (6.5%)+corn oil (2.5%) for FO diets. MNNG-treated rats had colonic tumor, while no tumors(adenocarcinoma and adenoma) than others. Tumor sizes in BT-MNNG rats ranged from 2mm papillary form to 15mm of polypoid. However, the size of tumors in PO-MNNG or FO-MNNG rats could not be measured by gross examination. BT-MNNG and CO-MNNG groups were higher in the level of plasma TXB2 and the ratio of c20 : 4/c20 :5 platelet. PO-MNNG groups were lower in the ratio of c20 : 4/c20 : 5(p<0.05) in fatty acid of colonic mucosal lipids suggesting that perilla oil and fish oil could reduce the level of PGE2 and TXB2 by modifying its precursor content and restrain tumor promotion in colon. Effect of perilla oil rich in $\alpha$-linolenic acid on colon carcinogenesis was similar to that of fish oil and thus perilla oil could have a protective effect against colon cancer possibly by inhibiting the production of arachidonic acid metabolite.

• Journal of Ecology and Environment
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• 제29권4호
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• pp.381-387
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• 2006

We analyzed the total yields and composition of essential oils in leaf extracts of Nepeta cataria by Gas Chromatography Mass Spectrometry (GC-MS). Thirty-six compounds representing 97.0% of total oil were detected. The major constituents of essential oils in Nepeta cataria were nepetalactone (90.9%), unidentified compound (Retention time 17.35; 1.82%), 1,8-cineol (1.49%), ${\beta}-caryophyllene$ (1.12%), and ${\beta}-pinene$ (1.078%). The volatile compounds in leaf extracts of N. cataria concentrated to nepetalactone ($88.83{\sim}93.33%$) remarkably. In the essential oil of N. cataria cis,trans-nepetalactone ($30.2{\sim}37.8%$) and cis,cis-nepetalactone ($31.5{\sim}37.0%$) were found as the main constituents. The effects of essential oil of N. cataria on the growth of six microorganisms (Bacillus cereus, B. subtilis, B. amyloliquefaciens, Escherichia coli, Staphylococcus aureus subsp. aureus, and Pseudomonas aeruginosa) were investigated. The essential oil of N. cataria had strong inhibitory effect on the growth of three fungal species (Bacillus cereus, B. subtilis, and B. amyloliquefaciens). The essential oil from N. cataria was found to have a low antimicrobial activity against Staphylococcus aureus subsp. aureus, while no activity were found against Escherichia coli and Pseudomonas aeruginosa. Results indicate the significant antimicrobial effect, which may be depended on the yield of nepetalactone.

• 한국식품영양학회지
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• 제9권3호
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• pp.331-335
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• 1996

In this study, the attempts were made to Investigate the effect of squalene (200 ppm) on the autooxidation of soybean oil The effect of mixed tocopherols (200 ppm) was also studied In the same way and the results of the study were compared with those of squalene. A put of a commercial soybean oil was stored at 45.0$\pm$0.5t for their autooxidation. The extent of the autooxidation was estimated from the changes of the peroxide value and % conjugated dienoic acid content of the ell substrates The results of the autooxidation, squalene In the soybean oil substrate showed antioxidant activity but the activity was weaker than that of mixed-tocopherols nth the same concentration. The induction periods of the control and substrates with the same concentration. The Induction periods of the control and substrates with squalene and mixed-tocopherols were 448.5 504.9 and 668.9 hours, respectively. Time required to Tech a POV of 30meq/kg oil.

• Tribology and Lubricants
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• 제15권1호
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• pp.98-107
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• 1999

In this work the effect of pressure drop at inner film due to centrifugal forces acting on the lubricating fluid is investigated for static and dynamic characteristics of floating ring journal bearing. The momentum effect of oil supply into a inner film through oil feeding holes of floating ring on the bearing performance is also studied. It is compared the pressure drop effects and the momentum effect of oil supply into a inner film fur all bearing performance parameters. It is shown that some performance of floating ring bearings can be controled by the momentum of oil supply into a inner film.

• 통합자연과학논문집
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• 제14권3호
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• pp.95-98
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• 2021

By far, studies on the effect of oral administration of peppermint essential oil on blood pressure are not consistent, increasing or decreasing. And the effect of inhalation of peppermint essential oil on blood pressure was not reported. This study was designed to clarify the effect of peppermint essential oil inhalation on the blood pressure and autonomic nervous system. Blood pressure and heart rate variability (HRV) as an indicator of autonomic nervous system activity were measured. The systolic and diastolic blood pressure was not changed significantly by inhalation of peppermint essential oil. Standard deviation of normal to normal (SDNN), a parameter of total activity of autonomic nervous system also was not changed significantly. High frequency (HF) power level, an indicator of parasympathetic nervous system activity was not changed by peppermint. These results indicate that action mechanism of peppermint essential oil on blood pressure is different by the method of administration, oral or inhalation.

• 한국응용과학기술학회지
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• 제21권4호
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• pp.320-326
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• 2004

We have extracted the natural pine-needles to use ethanol in solvent, and could obtain the refined oil component from pine-needles extract. We have tested the antimicrobial effect from microbe experiment and analyzed with ICP/OES, GC/MS. we could obtain the next conclusion from the result of this experiment. In the first result of this experiment we could know that in case of increasing concentration of pine-needles, the number of microbe decreased more and more. Also we could know that the refined oil component of pine-needles appeared the sterilization effect of S-aureus and E-coli after 96hrs and 120hrs. So we could know that the refined oil component of appeared effect to microbe. In the second result of this experiment we could know that inorganic materials of Ca, Mg, V, Mn etcs from pine-needles detected to ICP/OES analysis and the aromatic compounds from refined oil component of pine-needles was certificated to GC/MS analysis.