• Tribology and Lubricants
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• v.26 no.4
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• pp.240-245
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• 2010

This paper describes the influence on engine main bearing behavior of the oil film when the fuel is diluted on a diesel engine equipped with DPF system. Oil film pressure and the thickness is calculated in accordance to the fuel dilution. The calculation is based on the numerical analysis of the engine main bearing. As a result, the engine oil viscosity decreased as the fuel dilution increased. This led the increment of the maximum oil thickness pressure. Verification of the minimum oil film thickness settlement by the engine gas pressure and the fuel dilution was confirmed. Destruction possibility of the engine main bearing was foreseen when the engine speed was 2000 rpm with the fuel dilution 15% and the 5W40 engine oil.

• Proceedings of the KSRS Conference
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• 1999.11a
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• pp.243-248
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• 1999

From the lessons after the Nakhodka oil-spill in Jan. 1997, oil slick detection by using remote sensing data and assimilating the data to the simulation program is important for monitoring the oil-drift pattern. For this object, we are going to construct the oil-spill warning system for estimating the oil-drift pattern using remotesensing/numerical simulation Model. Additionally we plan to use this system for restorating oil-spill damage domestically, such as estimating the ecological damage and making the priority fur restorating the oil-spilled shoreline. This report is intended to summarize the role of geo-informatics in the oil spill accident by not only paying attention to the effect of information provision/information management via the map, but also reporting the interim result in part based on the details discussed in the processes of recovery support and environmental impact assessment during the Nakhodka's accident.

• Journal of Power System Engineering
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• v.17 no.6
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• pp.11-17
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• 2013

Esterified bio-diesel oil is normally used as blend oil of 3% that and 97% diesel fuel in Korea. Since specifics of it is similar to that of diesel fuel, availability of non-esterified bio-diesel oil that has a lower expenses of manufacturing is worthy of attention. However, bio-diesel oil has a demerit which it emits typically more NOx emission than diesel fuel. In this study, characteristic tests using blending oil with 95% gas oil and 5% bio-diesel oil were achieved at lower common rail pressure in order to improve this demerit. It was noticed that non-esterified bio-diesel oil has more similar characteristics to diesel fuel than esterified bio-diesel oil and it emits more NO emission by fuel NO mechanism.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2348-2355
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• 2015

Transformer mineral oil which is normally hydrocarbon based is non- biodegradable and pollutes the environment in all aspects. Though vegetable oils are eco-friendly in nature and potentially could be used in transformers as a replacement for the mineral oil, there usage is restricted because of their oxidative instability. The present work focuses on using rapeseed oil and pongamia (pongamia pinnata) oil as effective alternatives for the traditional mineral oil in power transformer. The oxidative stability of the rapeseed oil and pongamia oil is increased by using combinations of the natural and synthetic anti-oxidants as additives. The parameters like breakdown voltage, viscosity, flash point, fire point are measured for the rapeseed oil and pongamia oil with and without the additives as per IEC and ASTM standards. The results shown encouraging changes in the parameter values and ensures the use of the oils as a potential alternative insulation in power transformers.

• Proceedings of KOSOMES biannual meeting
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• 2003.05a
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• pp.205-209
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• 2003

The various pretreatment processes were evaluated for removal of oil pollutants with weathered oil contaminated seawater in a reverse osmosis desalination process. Weathered oil contaminated seawater was made by biodegradation and photooxidation with oil containing seawater. Coagulation, ultrafiltration, advanced oxidation processes and granular activated carbon filtration was used with pretreatment for dissolved organic carbon. Crude oil was removed but. weathered oil contaminated seawater was not removed by biodegradation and coagulation. DOC and E260 was removed with about 20 % and 40 % by membrane filter of cut off molecular weight 500. So, the most of dissolved organic carbon in weathered oil contaminated seawater was revealed that molecular weight was lower than 500. It is difficult to remove DOC in weathered oil contaminated seawater by advanced oxidation processes treatment, but, E260 was removed more high. However, DOC in weathered oil contaminated seawater was easily adsorbed to GAC. It is revealed that DOC was removed by adsorption.

• Tribology and Lubricants
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• v.9 no.1
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• pp.55-61
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• 1993

Recently, due to the erosion damage that were generated increasingly at alloy metals of slide bearing by cavity of lubricating oil with tendency of high speed and high output of reciprocating engine, there is a need to study the process on the formation of cavitation erosion, and the characteristic of cavitation erosion at lubricating oil environments under various condition for marine ship. Therefore, the apparatus of cavitation erosion experiment used 20 KHz, $24 \mu m$ piezoelectric vibrator. The main results obtained through this test method are as follows: 1. The max. erosion rate at lubricating oil environments was related to the change of space, oil film thickness, and shown to tendency of gear oil>system oil>turbine oil>mixed oil environments with different viscosity. 2. The pitted hole by cavitation erosion at high viscosity oil environments became small and deep, and in addition to, they appeared to be wide and shallow at low viscosity.

• Journal of Industrial Technology
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• v.31 no.B
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• pp.113-117
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• 2011

The purpose of this study is to determine the antimicrobial effect of tea tree oil a against pathogens relate to acne. Tea tree oil extracted from Australian Melaleuca alterifolia has been studied extensively for their antimicrobial properties against different type of bacteria and fungi. Tea tree oil has been reported to have antibacterial, antiinflammatory and antitumor activities, among others. By evaluating the antibacterial effect of Tea Tree Oil of Australia, the MIC value of Tea Tree oil against P. acnes was 0.05% and 0.5% against aerobic bacteria. This study showed that Tea Tree Oil has antibacterial effect against bacteria which induce acne. Tea Tree Oil had better antibacterial effect against P. acnes compared to aerobic bacteria. It is promising to develop a nature-based functional material for makeup product, which can cure and prevent acne.

• Culinary science and hospitality research
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• v.24 no.2
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• pp.79-86
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• 2018

The purpose of current study was to evaluate the oxidative stability of soybean oil after frying according to storage temperature. The soybean oil after 10 times deep fat frying with potato sticks (10% w/w of oil) were stored during 10 days at 30, 60 and $90^{\circ}C$ and chemical properties were determined. The acid value and peroxide value were the highest and the iodine value were the lowest when the oil stored at $90^{\circ}C$. Expecially, the production rate of peroxide was fast at over $60^{\circ}C$. According to the results, frying oil should not be stored for more than 6 days at $30^{\circ}C$ after use. Since the oil used had already produced unstable peroxides, oxidation could proceed relatively quickly even at low temperatures. Therefore, it is desirable to keep the used oil at a temperature as low as possible.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.13 no.1
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• pp.1-8
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• 2001

This paper deals with refrigerant-oil mixtures in a dehumidifying cycle. Two different oils such as Alkylbenzene(AB) and Polyol-esters(POE) lubricants are used for R134a to investigate the effect of miscibility on oil returnability. It was found that R134a/AB mixture had more unstable interface between oil and refrigerant than R134a/POE mixture. However, overall flow patterns of both refrigerant-oil mixtures were almost same. The minimum height of oil measured in the compressor was as high as twice of the least permissible height of oil in the compressor required to insure its reliability. Thus, it is considered that immiscible oil, i. e., AB for R134a can be used without causing oil returnability problem.

• Tribology and Lubricants
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• v.20 no.1
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• pp.33-40
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• 2004

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 when viscosity index of hydraulic oil is very high. 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. Performance of newly developed hydraulic oil based on used oil analysis is compared with previously used one. The properties of new formulation are the viscosity index of 140 and improved thermal stability consists of VHVI base oil. Field test results showed the possibility of extension of fluid life. Additionally, for development of high performance product, new required propertied and performances were discussed.