• Journal of Biosystems Engineering
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• v.40 no.2
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• pp.95-101
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• 2015

Purpose: During the start-up period, the response time of a hydraulic system increases in the winter because of the increased oil viscosity caused by the cold weather. The problems of delayed tractor starting and excessive wear of the clutch disk occur for these reasons. Therefore, this study develops an analysis model using the commercial hydraulic analysis program AMESim to examine the characteristics of delays in power shuttle starting at different oil temperatures. Methods: In the experiment, a tractor was stationary on a flat surface with the engine running at a constant speed of 1,080 rpm. The forward lever was then pressed to activate the power shuttle at three different oil temperatures, and the pressure changes were measured. The pressure on the forward clutch control valve was measured by a pressure gauge installed on the hydraulic line supplied to the transmission from the main valve. An analysis model was also developed and verified with actual tests. Results: The trend of the simulated pressures of the power shuttle is similar to that of the measured pressures, and a constant modulation period was observed in both the simulation and test results. However, the difference found between the simulation and test results was the initial pressure required to overcome the initial force of the clutch spring. Conclusions: This study also examines the characteristics of the delayed startup of the power shuttle at different oil temperatures through simulations.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.1558-1560
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• 2004

Liquid-immersed pole transformers have utilized an insulation system consisting of natural cellulose-based materials and mineral oil for many years. If the transformers are installed with the abruptly changing load over limitation, its insulation materials are apt to unexpected aging with high temperature. Therefore we have been conscious of developing a transformer that is more thermally stable then conventional types. To measure temperature distribution in the winding of conventional and newly designed transformers, temperature sensors were installed fordirect reading of oil and conductor temperatures at transformers. And we conducted accelerating aging test for these transformers. The measuring data had made use of the design to hybrid insulation system. Also we could find the possibility of this insulation system to apply in pole mounted transformers.

• Journal of Food Hygiene and Safety
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• v.12 no.2
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• pp.107-110
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• 1997

To examine the effects of residual phosphorus content on color reversion and storage stability of corn germ oil, the changes of Lovibond total color and stability of oxidation were determined according to the different storage periods at room and incubating temperature, respectively. The residual phosphorus content and storage temperature had the synergistic effect on color reversion during short time storage. The extent of color change was the greatest when oils were stored for 1.0∼1.5 years at room temperature and thereafter gradually tended to reverse color reversion. It is supposed that the double bonds of carotenoids in oils were oxidized and then turned to the volatiles such as epoxide, ionone, and etc. In contrast, the residual phosphorus content increased oxidation stability of oils. The residual phosphorus content was closely correlated with the color reversion and storage stability, respectively.

• Journal of the Korean Society of Safety
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• v.2 no.1
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• pp.59-71
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• 1987

A study has been made of the damping force phenomena of the shockabsorber for automobile. The main results obtained are as follows; 1) We can neglect friction loss between cylinder and piston, as it is very small compared to other damping force. 2) Damping force due to coil spring and disc valve shows comparatively stable at various piston speed and oil temperature. 3) Theoretical and experimental values are well agreed on relatively low piston speed. 4) Theoretical value on piston speed of 600mm/sec, 900mm/sec at oil temperature $20^{\circ}C$, $40^{\circ}C$, $60^{\circ}C$ and $80^{\circ}C$ is about 82% of experimental value. 5) Theretical value at oil temperature $-20^{\circ}C$, $0^{\circ}C$ is about 67% of experimental value.

• Tribology and Lubricants
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• v.13 no.4
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• pp.26-32
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• 1997

The heat generation of the angular contact and the deep groove ball bearing is studied experimentally and numerically. The temperature variation of the inner and outer races and the temperature increase distribution are measured for the shaft rotational speeds, preloads, viscosities of the lubricant and lubrication methods. The measured temperature distributions are used as the input data of the numerical simulation to estimate the heat generation rate at the bearing. The temperatures of the inner and outer race increase more rapidly and approach faster to their steady values as the rotational speed increases. The optimal viscosity of the oil to minimize the heat generation is 8~10 cSt at 4$0^{\circ}C$ when the oil-air lubrication method is adopted. The heat generation of the bearing increases with the rotational speed and depends more on the lubrication method than on the preload variation.

• Proceedings of the KIEE Conference
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• 2004.11d
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• pp.97-99
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• 2004

Liquid-immersed pole transformers have utilized an insulation system consisting of natural cellulose-based materials and mineral oil for many years. If the transformers are installed with the abruptly changing load over limitation, its insulation materials are apt to unexpected aging with high temperature. Therefore we have been conscious of developing a transformer that is more thermally stable then conventional types. To measure temperature distribution in the winding of conventional and newly designed transformers, temperature sensors were installed fordirect reading of oil and conductor temperatures at transformers. And we conducted accelerating aging test for these transformers. The measuring data had made use of the design to hybrid insulation system. Also we could find the possibility of this insulation system to apply in pole mounted transformers.

• Proceedings of the KSME Conference
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• 2000.04b
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• pp.398-403
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• 2000

Experimental study on the porous ceramic burner for oil burning has been performed. Temperature profile of the combustor and CO and NOx emission have been obtained for with and without porous ceramic plate. It is found that very uniform and high temperature region with porous ceramic plate can be realized due to high radiation emission from the plate and also obtained lower CO and soot particulate emission, when compared to the conventional burner. When this burning method is applied to conventional boiler of small heating capacity, it is found that near 6 and 7 percent increase in thermal efficiency could be obtained without a proper calibration for optimization.

• The Korean Journal of Pharmacology
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• v.5 no.2
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• pp.93-103
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• 1969

Saponin, essential oil, fat oil and alkaloidal fraction were fractionated from the ethanol extract of fanax ginseng. Effect of each fraction of Panax ginseng upon the temperature response induced by reserpine, chlorpromazine and nembutal was investigated in mice, so as to secure some hidden facets of each fraction of Panax ginseng acting upon central nervous system. The authors could arrive at some results, that is: (1) Inhibitory effect of Panax ginseng upon temperature decline induced by nembutal and chlorpromazine and potentiating action upon hyperthermia induced by reserpine reside mainly in saponin fraction and slightly in essential oil fraction. (2) The effect of Ginseng saponin on temperature response in nice seems to be related with the liberation of serotonin and histamine.

• Transactions of the Korean Society of Automotive Engineers
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• v.13 no.6
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• pp.99-104
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• 2005

The CARB in USA has demanded OBD functions that detect any deterioration of performance of OTS as well as a simple defect of OTS which can affect emission to meet the reinforced emission regulation. In this paper, OTS plausibility monitoring functions to meet the demand from CARB are discussed. The output from OTS is used for the diagnostics of the torque converter clutch stuck and the gear ratio synchronous error. It is possible to diagnose the abnormality of OTS function by considering the oil temperature characteristics which changes according to the driving status of vehicles. In result, the OBD regulations of the CARB can be satisfied obligating car manufacturer to detect any problems in OTS functions which can affect emissions.

• Journal of the Korean Society of Food Science and Nutrition
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• v.26 no.6
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• pp.1028-1032
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• 1997

Low-temperature crystallization method silver nitrate-impregnated silicic acid column chromatography were applied for the isolation of pure $\alpha$-linolenic acid(ALA) from perilla seed oil. ALA or 78% in purity(HALA; yield, 83%) was obtained from the fatty acid mixture(ALA, 65.7%) derived from perilla oil by the low-temperature crystallization method, when the mixture was frozen at -8$0^{\circ}C$ for 210min. ALA over 90% in purity(yield, 71%) was also obtained from HALA ethyl esters(ALA, 78%) by the silver nitrate-impregnated silicic acid column(100cm$\times$10cm, i.d.) chromatography. In addition, the silver nitrate-impregnated silicic acid could be semipermanently used for isolation of ALA, because $Ag^{+}$ ion was not dissociated from the stationary phase.