• Journal of Nutrition and Health
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• v.34 no.4
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• pp.367-374
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• 2001

Conjugated linoleic acid(CLA) is a naturally occuring group of derivatives of linoleic acid found in beef and dairy products. CLA has reported to reduce body fat. This study was designed to observe the effect of CLA supplementation on fat accumulation and degradation in male Sprague Dawley rats. Seventy two rats, weighing 150-180g, were divided into 2 groups according to the types of dietary fat(beef tallow or fish oil) and then each group was divided into 2 groups depending on CLA supplementation, i.e., BT, BT-CLA, FO, FO-CLA. All rats were fed experimental diet containing total fat at 12%(w/w) including CLA at 1% for 30 weeks. At 30 weeks, rats were sacrificed to measure TG, free fatty acid level in plasma, TG, lipogenic enzymes in lever and fat cell size, LPL and HSL activities in epididymal fat fad. Fish oil supplemented with CLA diet showed significant reduction in the food efficiency and weight in 30 weeks-fed rats. CLA supplement did not effect on plasma TG, hepatic TG levels and lipogenic enzymes activities in rats, but, fish oil significantly reduced, The LPL and HSL activities did not affected by CLA supplement and n-3 fatty acid rich fish oil. In conclusion, the results suggest that CLA supplement was not a proper way to reduce the fat accumulation in Sprague Dawley rats. Fish oil supplemented with CLA might better way to reduce the body fatness than fish oil itself. Therefore, It is recommended that further study be performed related to physiological and biochemical effects of CLA supplementation and n-3 fatty acid in rats for the reduction of body fatness.(Korean J Nutrition 34(4) : 367∼374, 2001)

• Journal of Soil and Groundwater Environment
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• v.12 no.5
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• pp.54-63
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• 2007

To examine the effects of amendments on heavy mineral oil degradation, a pilot scale experiment was conducted for over 105days. During the experiment, soil samples were collected and analyzed periodically for the determination of residual hydrocarbon and microbial activities. At the end of the experiment, the initial level of contamination ($6,205{\pm}173mgkg^{-1}$) was reduced by $33{\sim}45%$ in the amendment amended soil; whereas only 8% of the hydrocarbon was eliminated in the non-amended soil. Heavy mineral oil degradation was much faster and more complete in compost amended soils. Enhanced dissipation of heavy mineral oil in compost amended soil might be derived from increased microbial activities (respiration, microbial biomass-C) and soil enzyme activity(lipase, dehydrogenase, and FDA hydrolase) were strongly correlated with heavy mineral oil biodegradaton (P < 0.01).

• Journal of Life Science
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• v.24 no.6
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• pp.694-699
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• 2014

Indigenous microorganisms play decisive roles in biodegradation. In this study, eighty strains of hydrocarbon-degrading microbes were isolated from Incheon Bay. Among them, 12 strains were selected by an oil film collapsing method. The bacterial strain 'Incheon9' was eventually selected based on its relatively higher lipase and emulsification activities, and was identified as Acinetobacter sp. (NCBI accession code: KF54854). The optimum condition for the growth and emulsification activity of Acinetobacter sp. Incheon9 was $20^{\circ}C$, pH 7, and 1% NaCl. The optimum time for the best production of biosurfactant was 72 hrs. The oil degradation ability of Acinetobacter sp. Incheon9 was investigated by measuring the residual oils in the culture medium by gas chromatography (FID). This research provides foundational data for eco-friendly environmental remediation by microorganisms.

• Korean journal of food and cookery science
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• v.29 no.1
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• pp.53-62
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• 2013

Lipid oxidation and antioxidants changes in perilla oil emulsion added with chlorophyll were studied during storage in the dark or under 1,700 lux light at $25^{\circ}C$ for 48 h. The emulsion was consisted of perilla oil (33.12 g), 5% acetic acid (66.23 g), egg yolk powder (0.5 g), and xanthan gum (0.15 g), and Chlorophyll b was added to the emulsion at 0, 2.5 and 4 mg/kg. The lipid oxidation was evaluated by headspace oxygen consumption and hydroperoxide formation, and tocopherols and polyphenols were monitored by HPLC and spectrophotometry at 725 nm, respectively. The lipid oxidation of the perilla oil emulsion in the dark was not significant regardless of the addition of chlorophyll. Light increased and accelerated the lipid oxidation of the emulsion, and increased addition level of chlorophyll under light increased it further. However, there was no significant change in fatty acid composition in any case. Contents of tocopherols and polyphenols in the emulsion were not significantly changed during storage in the dark regardless of chlorophyll addition, indicating their little degradation. Tocopherols and polyphenols in the emulsion were significantly degraded during storage of the emulsion under light, and the degradation rate of polyphenols was increased with addition level of chlorophyll. The lipid oxidation of the perilla oil emulsion was inversely related with the residual amounts of tocopherols and polyphenols, with more dependent on the retention of polyphenols than that of tocopherols.

• Proceedings of the KIEE Conference
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• 1988.11a
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• pp.214-219
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• 1988

Aging process in transformer insulating oil is studied by measuring the leakage current in ceramic sensor. the current of a sensor developed if this paper shows a close relationship with the acid value and the breakdown voltage of the transformer oil. The sensor has excellent physico-chemical reaction to the oil and stable adsorption of conductive impurities. Therefore the experimental data show good reproducibility. From the detailed analysis of the leakage current, it may be proposed that the condition of transformer insulating oil in service can be checked portably.

• Journal of the Korean Society of Food Science and Nutrition
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• v.28 no.4
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• pp.890-894
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• 1999

Microencapsulation of anchovy oil as a core material in sodium alginate as a wall material was inves tigated. Microencapsulation was accomplished by injecting an oil/water emulsion, consisting of a mixture of liquefied sodium alginate and emulsifier, under high pressure through an orifice submerged in a calcium lactate solution. Microcapsules suspended in a dispersion fluid were observed under a fluorescence mi croscope to verify the presence of the capsules and to note coalescence or degradation of the capsules. Optimum conditions for microencapsulation of anchovy oil were obtained when 1.0% aqueous solution of sodium alginate contained 3% of a 1:1 ratio of ESPR 25(polyglycerine＋polylinoleate) and TW 20(sorbitan laurate＋ethylene oxide) as an emulsifier in terms of capsule size and size distribution, and emulsion stability. The airless sprayer produced microcapsules with a diameter between 15.9 and 73.9 m with different concentration of a wall material. The optimum mixing ratio of wall material to core material was 90:10(wt/wt). 0.2% calcium lactate was appropriate as a dispersion fluid.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.10
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• pp.2159-2164
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• 2002

This paper reports on the effects of additional factors on the engine friction characteristics. The total friction loss of engine is composed of pumping and mechanical friction loss. The pumping loss was calculated from the cylinder pressure, and the mechanical friction loss was measured by strip-down method under the motoring condition. The various parameters were tested. The engine friction loss was much affected by oil and coolant temperature. The low viscosity oil was very effective to reduce the friction loss, and friction modifier was very useful to reduce the friction loss at lower engine speed. The engine friction loss was varied with engine running time because of surface roughness decreasing and oil degradation. To prevent oil-churning effect, it was very important to maintain the proper oil level. The presented results will be very useful to understand friction characteristics of engine.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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• 2005.04a
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• pp.159-162
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• 2005

In this study, a two-liquid-phase (TLP) bioreactor was conducted to enhance the biodegradation efficiency and rate of PAH. Phenanthrene was degraded efficiently irrespective of the type and the amount of water-immiscible liquid (WIL). The degradation efficiency of anthracene was much higher in paraffine oil than in silicone oil because the mass transfer of anthracene was different in the two WILs. Pyrene was only transferred from soil to WIL during 5 days. It seemed that the degradation of PAH in the TLP bioreactor was mainly dependent on the mass transfer of PAH.

• Proceedings of the KIEE Conference
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• 1998.07e
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• pp.1746-1748
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• 1998

In this paper, the relation between the increment of metallic content such as copper(Cu) and iron(Fe) according to degradation of pole-transformer oil and change of electrical characteristics according to increment of metallic content was studied. As the result, electrical characteristics was decrease according to increment of metallic content, especially copper content, and the trend of T.C.G(Total Carbonic Gas) agreed with the trend of copper content.

• Korean Journal of Food Science and Technology
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• v.23 no.4
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• pp.465-470
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• 1991

In order to investigate the thermal and oxidative stability of different frying oils including soybean oil, palm oil, two blended oils of soybean-palm (5 : 5 and 7 : 3) and shortening, physico-chemical properties such as acid value, peroxide value, TBA value, degree of coloring, refractive index and specific gravity of the frying oils were measured during the preparation of French fried potatoes by repeated frying. The instability of soybean oil against thermal and oxidative degradation could be lessened by using blended oils in which the ratio of palm oil to soybean oil is more than 50%.