• Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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• 2002.10b
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• pp.353-354
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• 2002

This study represents the newly advanced formulation of hydraulic fluids for extended drain interval and introduces the performance results of used oil samples from various excavators. The used oil samples, in this paper, show that there is a sharp change in viscosity drop and moderate additive depletion. For the extension of hydraulic fluid life. it is necessary to improve the stability of viscosity and oxidation. New target properties from the used oil analysis were proposed for extended life. Hydraulic oil with the viscosity index of 140 and improved thermal stability consists of group III base oil, showed the possibility of extension of fluid life.

• Transactions of the Korean Society of Automotive Engineers
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• v.1 no.3
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• pp.46-54
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• 1993

In order to develop a fuel-efficient gasoline engine oil, an experimental study was conducted using an engine dynamometer, a passenger car and the SRV machine. Oil samples with different viscosity were prepared by adding several friction modifiers to select the best one and also to investigate the effect of the viscosity grade. From the study, we have developed engine oils which result in good fuel economy. The viscosity grade of 7.5W/30 was best among the oils investigated with respect to fuel economy and a fatty amine type friction modifier had the good fuel-economy property.

• Food Science and Biotechnology
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• v.18 no.6
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• pp.1371-1378
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• 2009

The aim of this study is to elucidate the anti-inflammatory activities of chopi (Zanthoxylum piperitum A.P. DC.) essential oil. Essential oil (EO) of chopi was extracted by steam distillation method, and its major constituents were limonene and geranyl acetate. Chopi-EO decreased approximately 38% of nitrite production, as compared to the lipopolysaccharde (LPS)-induced nitrite production. However, chopi-EO and its components did not quench nitric oxide (NO) chemically in cellfree system, and markedly inhibited approximately 40.4% of inducible nitric oxide synthase (iNOS) mRNA transcription. In addition, the inhibition of E-selectin gene transcription by chopi-EO caused the suppression of cellular adhesion. These results suggest that chopi-EO may exert potential anti-immunological inflammatory activity.

• Journal of Navigation and Port Research
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• v.35 no.9
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• pp.765-776
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• 2011

For container shipping company, fuel oil prise is a considerable expense. Since 2008, fuel oil prises have risen dramatically. An increasing fuel oil price in container shipping, in the short term, is only partially compensated through surcharges and may affect earnings negatively. This study discusses the impact of an increasing fuel oil price and capital costs for vessels on the Asia-Europe trade of 'H' Shipping Company. According to the result of 'H' carrier's operation in 2008, there were no cost differences between 8 and 9 vessels operations in case of fuel oil price with USD 169/tons while adopting USD 31,818 as a fixed cost. We can expect that the fuel oil price will not go lower than USD 200/Ton on the basis of current high oil price phenomenon. When the fuel oil price is over USD 200/ton, 9 vessel operation is more economic than 8 vessel operation even if the fixed cost is over USD 35,000.

• Korea Trade Review
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• v.47 no.3
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• pp.141-156
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• 2022

This study intends to examine the regional blocs of the international crude oil futures market by analyzing the dynamic conditional correlation between the international crude oil futures markets using the DCC-GARCH model. For statistical data, from April 2, 2018 to March 31, 2022, international crude oil futures prices such as Europe, the United States, China, and Dubai were used. To summarize the results of the study, first, the phenomenon of regional blocs in the international crude oil futures market is occurring, and it is found that it is gradually strengthening as time goes by. Second, it was found that the dynamic correlation of the international crude oil futures market is temporarily strengthened when a supply-demand imbalance problem occurs due to a global shock. Third, it was found that the volatility of the Chinese crude oil futures market affects the international crude oil futures market. This study confirmed that the regional blocs phenomenon in the international crude oil futures market is strengthened as time goes by. In particular, it suggested that China's influence in the international oil market would increase.

• Journal of Nutrition and Health
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• v.26 no.5
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• pp.513-523
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• 1993

In this experiment, we investigated the hypolipidemic and antithrombotic effects of rats fed diets with different common oils in Korea for different feeding periods(4 weeks or 12 weeks), using Korean sesame oil, perilla oil, rice bran oil and mixed oil. W-3/w-6 ratio of each group was 0.001, 1.44, 0.03 and 0.112, respectively. P/S ratio of each group was 9.64, 10.49, 5.58 and 1.68, respectively. The result were as follows: 1) According to the age, body fat accumulation was increased. 2) Perilla oil(w-3 rich) decreased total lipid, triglyceride and total cholesterol, and increased HDL/total cholesterol ratio. 3) With regard to the compositono of platelet fatty acids, Perilla oil increased w-3/w-6 ratio of the platelet. Perilla oil lengthened bleeding time and decreased MDA(MalonDAdehyde) formation which determined in place of Thromboxane A2(TXA2) in platelet. This result can suggest that linoleic acid of perrilla oil seem to supress the conversion of linoleic acid to arachidonic acid(AA 20:4, w-6) and eicosapentaenoic acid(EPA, 20:5, w-3) trannnsformed from linolenic acid to suppress the conversion of arachidonic acid to TXA2. Since TXA2 is platelet-aggregating and vasoconstricting agent, the reduction of TXA2 tgeneration by platelet with increased linolenic acid intakes shows prologed bleeding time. In conclusion, w-3 rich perilla oil has strong hypolipidemic and antithrombotic effects by changing fatty acid profiles of the platelet.

• Archives of Pharmacal Research
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• v.27 no.3
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• pp.295-299
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• 2004

The antifungal activities of the essential oil from Agastache rugosa and its main component, estragole, combined with ketoconazole, one of the azole antibiotics commonly used to treat infections caused by Trichophyton species, were evaluated in this study. The combined effects were measured by the checkerboard microtiter and the disk diffusion tests, against T. erinacei, T. mentagrophytes, T. rubrum, T. schoenleinii and T. soudanense. Susceptibility of the five Trichophyton species to the oil alone, or ketoconazole alone, differed distinctly. The fractional inhibitory concentration indices (FICI) of ketoconazole combined with estragole or A. rugosa essential oil, against the tested Trichophyton species, were between 0.05 and 0.27, indicating synergistic effects. These drug combinations exhibited the most significant synergism against T. mentagrophytes, with FICIs of 0.05 and 0.09 for estragole and the essential oil fraction from A. rugosa, respectively. Isobolograms based on the data from checkerboard titer tests also indicated significant synergism between ketoconazole and the Agastache oil fraction or estragole, against the Trichophyton species evaluated. Trichophyton susceptibility to ketoconazole was significantly improved by combination with the Agastache rugosa oil fraction or its main component, estragole.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.25 no.10
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• pp.791-797
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• 2012

Mineral insulating oils are an important insulating materials in oil-filled transformer. However, the mineral oil is the cause of the environmental problem. The vegetable oils are substitutes for mineral oil because of its biodegradability characteristic. As large size and high rating of the transformer increases, the losses increase at a faster rate. So insulating oil is forced circulation in the oil-filled transformer by using oil pumps. The flow electrification occurs when insulating oil was forced to be circulated. To check the flow electrification, had conducted experiments varying factors. As a result, the streaming electrification could see the changes according to flow velocity, oil temperature and insulation materials.

• The Korean Journal of Ecology
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• v.23 no.2
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• pp.149-155
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• 2000

The allelopathic effects of Artemisia lavandulaefolia were studied using several test plants and microbes. Aqueous extracts and volatile compounds of A. lavandulaefolia inhibited seed germination, seedling and root growth of the test species such as Achyranthes japonica. Lactuca sativa, Artemisia princeps var. orientalis. Oenothera odorata, Plantago asiatica. Aster yomena, Elsholtzia ciliata, and Raphanus sativus var. hortensis for. acanthiformis. The root growth of test species was more affected than shoot growth by allelochemicals of A. lavandulaefolia. Essential oil of A. lavandulaefolia had antibacterial and antifungal effects. However, the antimicrobial activity of the essential oil was dependent upon the microbial species and concentrations. Callus growth of Oryza sativa, Brassica campestris subsp. napus var. pekinensis and Achyranthes japonica was sensitive by the essential oil of A. lavandulaefolia. Twenty three chemicals were identified from A. lavandulaefolia essential oil by gas chromatography. Primary allelochemicals among them were 1, 8-cineole, 1-$\alpha$-terpineol, $\alpha$-terpinene. camphor, 2-buten-1-ol and azulene. We concluded that aqueous extract and essential oil of A. lavandulaefolia were responsible for allelopathic effects.

• Journal of the Korean Society of Food Culture
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• v.23 no.1
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• pp.26-32
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• 2008

: In this experiment, three samples of oils were used. These oils were hydrated soybean oil, pure soybean oil and regular soybean oil. Oil was used after heating at $235-240^{\circ}C$ every four hours term and total heating hours was 16 hours. The physio-chemical analysis and sensory evaluation were performed on these oils. The hydrated soybean oil showed lower acid, peroxide and carbonyl value than the other two oils (p<0.05 or p<0.001). The other two oils were more affected in rancidity than the hydrated soybean oil. In color test, whereas L value lowed during the heating time, a and b value increased during the heating time. The tendency of high L value and low b value in a long-time heating was more apparant on the pure soybean oil and the regular soybean oil than on the hydrated soybean oil (p<0.05). In sensory evaluation, color and rancidity order increased during the heating time. The hydrated soybean oil showed color and rancidity order than the other two oils. In overall quality test, the pure and regular soybean oil that had been used for 12 and 16 hour were not preferable. The hydrated soybean oil that had been used for 16 hour were not preferable. In sensory evaluation, the hydrated soybean oil, the pure and regular soybean oil did not show a apparent difference, although the hydrated soybean oil had a little better scores on the overall quality.