• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1992.11a
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• pp.60-63
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• 1992

This paper presents the effect of moisture and dust on streaming electrification in transformer oil, in order to investigate the electrification tendency of oil adding moisture and dost. Authors designed series electrification device to analyse streaming electrification phenomena easily. Experimental results show that adding of moisture and dust in oil decreased charging level and it was dominant in case of moisture.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.3
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• pp.44-50
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• 2002

The connecting rod big-end bearing is one of the most heavily loaded components of the lubrication system of high-speed combustion engines. The supply oil flow has to pass to the main bearing and the rotating crankshaft before entering the connecting rod bearing. It is common knowledge that the centrifugal forces due to the crankshaft rotation influence the oil flow to connecting rod bearing through the oil supply bore, especially, when the oil supply system to the connecting rod bearing has a 180$^{\circ}$circumferential groove via a single drilling in the crankshaft. In this case, it should be confirmed that the groove oil pressure in the main bearing is sufficient to overcome these centrifugal forces. For the purpose, the dynamic oil pressure before entering oil supply bore to the connecting rod bearing was measured instead of averaged oil pressure in main gallery. Experimental test results show that the dynamic oil pressure in the oil groove was more useful than that of main gallery. And it was also found that the oil pressure fluctuation in the groove was sensitively affected by the reduction of the main bearing clearance.

• Tribology and Lubricants
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• v.24 no.1
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• pp.21-26
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• 2008

A pin bush bearing is one of the most important element in the piston engine which is joined a piston to a connecting rod. A pin bush is suffered by heat and changeable repeat loads, which are come from the explosive gas heat and pressures during a reciprocating stroke. Therefore, a tribological behavior of pin bush bearings is very severe compared to other parts of a piston assembly. To keep a stable operation of pin bush bearings effectively, it would be satisfied with proper oil film strength for severe operating conditions and durability, which are strongly related to the oil film thickness, oil film pressure, and a friction loss power. The computed results show that the viscosity of engine oils slightly affects to the minimum oil film thickness and oil film pressure distribution, but is an influential parameter on a total friction loss power. Thus the low viscosity engine oils for an increased operation condition should select a high level of base oil and add a viscosity index improver as an oil film additive.

• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.111-112
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• 2002

The influence of aerated oil on a high-speed proceeding bearing is examined by using the classical thermohydrodynamic lubrication theory coupled with analytical models for viscosity and density of air-oil mixture in fluid-film bearing including the live surface tension of aerated oil. Convection to the walls and mixing with supply oil and re-circulating oil are considered. The considered parameters for the study of bubbly lubrication are oil aeration level, air bubble size and shaft speed. The results show that, if the live surface tension is considered, the effect of air bubbles on the bearing load capacity is reduced due to temperature engagement comparing with that under the condition of a constant surface tension.

• Korean Journal of Environmental Biology
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• v.22 no.4
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• pp.513-518
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• 2004

Pine needle oil and Korean medicinal herbs (KMH) are known as effective therapeutic agents on various blood vessel disease. We have already reported the ameliorative effect of complex of pine needle oil and Korean medicinal herbs against hyperlipidemia. But safety and non - toxicity of pine needle oil and Korean medicinal herbs to normal animal cells have not been studied clearly. In this study, we investigated whether pine needle oil and Korean medicinal herbs show side effects on rat or not. These materials were administered to rats, and subacute toxicity was examined by measuring the hematological values, CBC differentiation, biochemical levels of blood (TP, total protein; albumin; ALP, alkaline phosphotase; AST, aspatate aminotrans- ferase; ALT, alanine aminotransferase; T-Chol., total cholesterol; T-Bil., total bilirubin) and urine analysis, suggesting that the sample have no side effects and cytotoxicity. These results indicate that the complex of pine needle oil and Korean medicinal herbs may effective non- toxic, safety therapeutic agents on hepatocytes and hyperlipidemia.

• Proceedings of the KIEE Conference
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• 1992.07b
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• pp.931-933
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• 1992

The static charges generated at the interface between the insulating oil and the solid materials, can be affected by impurities such as moisture. This paper investigated the charging tendency of clean oil and the oil with moisture in stainless steel pipe. The experimental results show that static electrification of the oil with moisture is smaller than that of the clean oil, and the oil is positively charged.

• Journal of the Optical Society of Korea
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• v.20 no.1
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• pp.204-211
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• 2016

Oil pollution seriously endangers the biological environment and human health. Due to the diversity of oils and the complexity of oil composition, it is of great significance to identify the oil contaminants. The 3-D fluorescence spectrum combined with a second order correction algorithm was adopted to measure an oil mixture with overlapped fluorescence spectra. The self-weighted alternating trilinear decomposition (SWATLD) is a kind of second order correction, which has developed rapidly in recent years. Micellar solutions of #0 diesel, #93 gasoline and ordinary kerosene in different concentrations were made up. The 3-D fluorescence spectra of the mixed oil solutions were measured by a FLS920 fluorescence spectrometer. The SWATLD algorithm was applied to decompose the spectrum data. The predict concentration and recovery rate obtained by the experiment show that the SWATLD algorithm has advantages of insensitivity to component number and high resolution for mixed oils.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.8
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• pp.813-820
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• 2015

Straight vegetable oil (SVO) is widely recommended as fuel for diesel engines in general and especially for marine diesel engines. However, SVOs used directly as fuel for diesel engines may cause problems for the engines; SVOs blended with diesel oil are a better choice. To widen understanding of the possibility of using blended SVOs as fuel alternatives, this paper presents results of experimental research on the combustion of blended straight vegetable oil in a marine diesel engine's cylinders. Results show that the fuel combustion process have the same curves as in simulations and, in the case of using blended fuels with up to 20% palm oil, the test diesel engine technical parameters such as engine output, exhaust gas temperatures, and specific fuel consumption are very similar to those of diesel oil (DO). Based on these results, marine diesel engines are strong potential applications and particularly recommended for the use of SVO blends.

• Natural Product Sciences
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• v.14 no.1
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• pp.27-31
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• 2008

We have evaluated the combined antifungal effects of the essential oil from Eucalyptus globulus or its main component 1,8-cineole with ketoconazole. Checkerboard microtiter tests were used to analyze their effects against three Candida and six Trichophyton species. The susceptibility of the Trichophyton species to E. globulus essential oil differed distinctly. The fractional inhibitory concentration indices (FICIs) against the tested Candida species ranged between 0.09 and 0.38 for ketoconazole combined with E. globulus essential oil or 1,8-cineole, indicating significant synergism between ketoconazole and the oil samples. Similar experiments using Trichophyton species resulted in FICIs between 0.28 and 0.63, indicating relatively weaker combined effects than those observed with Candida species. Thus, the data reported here show that the anti-Candida effects of ketoconazole can be significantly improved in the presence of E. globulus essential oil or 1, 8-cineole.

• Tribology and Lubricants
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• v.17 no.4
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• pp.321-334
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• 2001

The influence of aerated oil on high-speed journal bearing Is examined by thermohydrodynamic lubrication theory to lubrication with mixtures of a Newtonian liquid and an ideal gas. For this purpose, analytical models for viscosity and density of aerated oil in fluid-film bearing are applied. Convection to the walls, mixing with supply oil and re-circulating oil, and some degree of journal misalignment are considered. The results show that deliberate oil aeration can increase the load capacity of high-speed plain Journal bearing. And the load capacity is increased more by oil aeration under the conditions of shaft misalignment and higher speed.