• The Korean Journal of Food And Nutrition
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• v.11 no.1
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• pp.6-10
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• 1998

It was determined to effects on cold test(CT) and smoke point (SP) of deodorizing temperature(DT) in corn oil. Increase of DT was induced to decrease of CT in deodorized oil, which was against the winterized oil inleted. Especially, the decrease of CT in deodorized oil was sharply at more than 26$0^{\circ}C$, this phenomenon was supposed to according the increase of total saturation degree as well as SU2, S2U, and S3 type triglyceride content. On the other hand, SP was showed the highest value as 242$^{\circ}C$ at DT as 24$0^{\circ}C$, the value was decreased to 235~238$^{\circ}C$ at DT as 245~27$0^{\circ}C$. This phenomenon was appeared in inverse proportion to the acid value of sample oils. Accordingly, high temperature deodorizing proved to be a very undesirable effect between general physicochemical characteristics, fatty acid composition and CT, SP etc.

• Korean Journal of Food Science and Technology
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• v.29 no.3
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• pp.407-411
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• 1997

Effects of heating time and storage temperature on the oxidative stability of heated palm oil were studied. Palm oil was heated at $150^{\circ}C$ for 0, 1, 10 or 20 min and stored at 4, 20 or $65^{\circ}C$. The oxidative stability of the sample was evaluated by determining peroxide value of the oil and measuring the volatiles in the headspace of the sample. Significant difference in the peroxide or volatile formation was observed (p<0.05) in heated palm oils between samples stored at 4 or $20^{\circ}C$ and those stored at $65^{\circ}C$. Pentane, hexanal, heptane and total volatiles increased with heating time, while storage temperature did not significantly affect their formation, indicating that heating time played more important role in volatile formation in the heated palm oil than storage temperature. However, adverse results were observed for the formation of peroxide. The interaction effect of heating time and storage temperature on the oxidative stability of heated palm oil was also observed.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 1989.10a
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• pp.65-70
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• 1989

This paper presents resarch results on the use of a corona detector and a pulse counter in order to diagnose for oil transformers. Using these experimental apparatus, tests were carried out on a typical transformer oil containing different carbonized paper and various moisture contents to measure the picocoulomb val-ues and pulse count. Through the result of this study it was found that the picocoulomb values and pulse count of corona were depended on the getting stained in transformer oil. The amplitude of the partial discharge amount and the number of pulse were decreased up to 70 [。c] and then was increased as the oil temperature goes up. It was concluded that the determinati-on level for diagnosis of oil transform-er was taken into account the temperatu-er of transformer oil, The use of pulse counter method, which have been taken the same property of voltage and temperature variation for the corona measurement mothod, considera-bly increase insulator avilability.

• Transactions of the Korean Society of Automotive Engineers
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• v.2 no.5
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• pp.1-10
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• 1994

By applying of total electric capacitance method on engine connecting rod bearing during engine operating, the influence of engine operating conditions and lubricants on bearing oil film thickness was investigated. Minimum oil film thickness increases with kinematic viscosity, but as increasing of viscosity, the increasing ratio of film thickness is reduced. Also minimum oil film thickness increases with engine speed but there is a limit. Above this limit, film thickness decreases in opposition because of crankshaft inertia. As increasing of engine torque and oil temperature, munimum oil film thickness decreases linearly. For non-Newtonian oils, the correlation between $100{\circ}C$ kinematic viscosity and munimum oil film thickness is very poor.

• Journal of the Korean Society of Safety
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• v.24 no.6
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• pp.150-156
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• 2009

The oil pressure switch(OPS) for automobile is very important part to prevent an overheated engine and other problems by checking the operation of an engine oil system and displaying oil signs on a dashboard. OPS is the part that receives various stress caused by temperature, vibration, and corrosion in an engine room. Regarding existing steel OPS cases, there occur field errors due to the rust, and much concern comes from the low anticorrosion caused by CR6+ Free according to the restrictions of heavy metals. Therefore, the study analyzed average life, the failure rate, and reliability through the tests of performance according to temperature changes, mechanical strength, and run-test in order to confirm if the use of the oil pressure switch with Al of anti-corrosion can improves the reliability, instead of the existing steel products.

• Journal of the Korean Professional Engineers Association
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• v.45 no.6
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• pp.28-32
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• 2012

Namhae chemical is one of the largest fertilizer manufacturing company in Korea which company has operating 4 unit agitator gear boxes and producing variety kinds of fertilizer production. The gearbox operating temperature of agitator is approximated in $55^{\circ}C{\sim}90^{\circ}C$ and required to keep operating continuous without stopping. The system required high performance oil and longer oil drain interval as limited workforce in maintenance team. It was lubricated by mineral gear oil of ISO VG 320 and also need to change to new oil frequently. Namhae Chemical would expect to keep stable operating condition without shut down and consider, lower cost of operation and equipment protection.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.12 no.6
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• pp.589-598
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• 2000

The vapor-liquid equilibrium and miscibility measurement apparatus was developed and used to obtain data for refrigerant/oil mixture. The vapor-liquid equilibrium and miscibility data for R-410a/POE32 and R-410A/POE46 oil mixtures are obtained over the temperature range from -20 to $60^{\circ}C\;with\;10^{\circ}C$ intervals and the oil concentration range from 0 to 90 wt%. Using the experimental data, an empirical model is developed to predict the temperature-pressure-concentration relations for R-410A/POE oil mixtures at equilibrium. In the R-410A/POE32 oil mixture, the average root-mean-square deviation between measured data and calculated results from the empirical model is 2.00% and in the R-410a/POE46 oil mixture, that is 3.69%. Flory-Huggins theory is also used to predict refrigerant/oil mixture behavior. Miscibility for R-410A/POE32 oil mixture was observed all over the experimental conditions. Immiscibility for R-410A/POE46 oil mixture was observed at the low oil concentrations(10~30 wt%).

• Transactions of the Korean Society of Mechanical Engineers B
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• v.26 no.8
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• pp.1153-1163
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• 2002

A transient analysis on temperatures of fuel and oil in hydraulic and lubrication systems in an aircraft was studied using the finite difference method. Numerical calculation was performed by an explicit method with modified Dufort-Frankel scheme. Among various missions, air superiority mission was considered as a mission model with 20% hot day ambient condition in subsonic region. The ambience of the aircraft was assumed as turbulent flow. Convective heat transfer coefficient were used in calculating heat transfer between the aircraft surface and the ambience. For an aircraft on the ground, an empirical equation represented as a function of free-stream air velocity was used. And the heat transfer coefficient for flat plate turbulent flow suggested by Eckert was employed for in-flight phases. The governing equations used in this analysis are the mass and energy conservation equations on fuel and oils. Here, analysis of fuel and oil temperature in the engine was not carried out. As a result of this analysis, the ground operation phase has shown the highest temperature and the largest rate of temperature increase among overall mission phases. Also, it is shown that fuel flow rate through fuel/oil heat exchanger plays an important role in temperature change of fuel and oil. This analysis could be an important part of studies to ensure thermal stability of the aircraft and can be applicable to thermal design of the aircraft fuel system.

• Korean Journal of Food Science and Technology
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• v.21 no.3
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• pp.331-337
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• 1989

In order to investigate the method for extension of shelf-life of Kimchi, the effect of low temperature heating and addition of mustard oil on pH and total acidity of Kimchi during storage at $15^{\circ}C$ were studied. Mustard oil was found to have the antimicrobial effect on the major lactic acid bacteria of Kimchi such as Lactobacillus plantarum, Lactobacillus brevis, Leuconostoc mesenteroides and Pediococcus cerevisiae, Addition of 200p.p.m. mustard oil, 0.1% mustard powder and 0.01% $H_2O_2$ to Kimchi effectively reduced the fermentation rate of Kimchi. Low temperature heating of salted cabbage and addition of 200p·p.m. mustard oil and 0.01% $H_2O_2$ to seasonings extented the time reaching optimum ripening of Kimchi about 2.5 times longer than control. Combination of low temperature heating, addition of mustard oil and $H_2O_2$ to seasonings and post low temperature heating delayed fermentation time Kimchi about 5 times longer than control after 15 days storage at $15^{\circ}C$.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1689-1690
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• 2008

In this paper, The method of a temperature rasing forecast is suggested and simulated. The data used in this simulations exists in the KD Power and it was obtain by real transformer. The method of temperature forecast is based on a top oil temperature rising modeling which is proposed by the IEEE journal. We propose modifications of a modeling that accurately predicts a future transformer temperature. This Method is verified by simulations.