• Proceedings of the KIEE Conference
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• 2005.10a
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• pp.82-85
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• 2005

Organic EL has been expected to adopt to a new styles of technology that make flat display after Tang & Vanslyke made good electric luminescence device in late 1980s. Their studies based on multi layer structure that consists of emitting layer and carrier transporting layer using proper organic material. In this study, we made multi layer device using $Eu(TTA)_3(phen)$ as a luminescence material by PVD and investigate luminous properties of each device. But oxidization of organic layer by ITO, energy walls in both pole interface, contaminations of ITO surface, importance of protecting membrane, diffusive dimming of light to cathode organic layer, these causes of degradations are common facts of a macromolecule and micromolecule. We think these degradation caused by the impact of heat and electro-chemical factor, bulk effect and interface phenomenon, and raise a question.

• Proceedings of the KIEE Conference
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• 2008.11b
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• pp.89-91
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• 2008

Organic EL has been expected to adopt to a new styles of technology that make flat display after Tang & Vanslyke made good electric luminescence device in late 1980s. Their studies based on multi layer structure that consists of emitting layer and carrier transporting layer using proper organic material. But oxidization of organic layer by ITO, energy walls in both pole interface, contaminations of ITO surface, importance of protecting membrane, diffusive dimming of light to cathode organic layer, these causes of degradations are common facts of a macromolecule and micro molecule. We think these degradation caused by the impact of heat and electro-chemical factor, bulk effect and interface phenomenon, and raise a question.

• Proceedings of the KIEE Conference
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• 2002.06a
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• pp.110-113
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• 2002

Organic EL has been expected to adopt to a new styles of technology that make flat display after Tang & Vanslyke made good electric luminescence device in late 1980s. Their studies based on multi layer structure that consists of emitting layer and carrier transporting layer using proper organic material. In this study. we made multi layer device using $Eu(TTA)_3(phen)$ as a luminescence material by PVD and investigate luminous properties of each device. But oxidization of organic layer by ITO. energy walls in both pole interface. contaminations of ITO surface, importance of protecting membrane, diffusive dimming of light to cathode organic layer. these causes of degradations are common facts of a macromolecule and micromolecule. We think these degradation caused by the impact of heat and electro-chemical factor, bulk effect and interface phenomenon. and raise a question.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.29 no.4
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• pp.218-224
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• 2016

The surface of Mg alloy, AZ31 and AZ91, were treated by PEO (plasma electrolytic oxidation) in Na-P system electrolyte, with different applied voltage and time. Thickness, roughness and X-ray crystallographic analysis revealed several results. The more applied time and voltage of PEO treated, the thicker oxidized surface coating layer were covered. And surface roughness increased with the thickness of oxidized layer. It was thought that when oxide layer grew, resistivity and breakdown voltage increased with the thickness of layer, and then, the energy of micro plasma need to be higher then before. So, it made craters and pores of surface become greater, which were responsible for the coarse surface.

• Journal of the Korean Society of Safety
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• v.26 no.2
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• pp.26-31
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• 2011

In this paper, the safety diagnosis using thermal image analysis is described for power equipments. The conventional three-phase comparison method has only provided the results of thermal comparison for the equipments. The proposed method defines the conditions of poor connection by visual checks, and supports the criteria with each thermal rise step. As a result, the thermal difference from $5^{\circ}C$ to $10^{\circ}C$ meant the warning state. In addition, the thermal difference more than $10^{\circ}C$ meant that the connection status was unbalanced. In this case, the countermeasure might be the internal load distribution. If the thermal difference more than $20^{\circ}C$ is observed, it means a hot spot at the poor connection. If the hot spot is observed all over the surface, its cause was the unbalanced load, which made the conductive parts discolored and raised the possibility of oxidization or $Cu_2O$ generation. This diagnostic technology employing thermal image analysis method can be directly applied in the field and ensures the safety of equipments.

• Journal of radiological science and technology
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• v.2 no.1
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• pp.71-83
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• 1979

Not only the insulating oil used for extra high voltage and high capacity transformer has a lot of possibilites of a corona discharge in oil, but the oil is easily degraded by a response of light oxidization. This study is either to classfy, with priority given to a transformer oil produced in Korea belonging to, the insulating oil No. 2, the sample irradiated the ultraviolet rays, treated a corona discharge in oil by a high voltage DC source and done nothing, or to measure the characteristics of breakdown, V-i, I-t and electrode material. The obtained results can be summarized as followings: (1) Unless the sample is contacted with the air, on the process to irradiate the ultraviolet rays, the sample less influence on the changes of the electric characteristics. At the same time, if the sample is contacted with the air and irradiated the ultraviolet rays, the sample shows a remarkable changes of the electric characteristics, and a declined breakdown strength. This tells us that the influence of the light irradiation must be considered as a primary factor of degrading the insulating oil. (2) In the oil treated by a corona discharge, breakdown voltage is declined more than in the oil not to be treated with it. This means that the degradation of the insulating oil is getting increased by a corona discharge in oil. (3) It shows that the increase of conducting current has little to do with breakdown voltage. (4) The conducting current depending on the electrode materials can be put in order by value as Al>Cu>Fe. This is due to the differences of the work function of each metals, and an chemical reaction with the insulating oil. These result can be a great help in verifying the degradation progress of the insulating oil and furnish a new technical information to the manufacturers of the insulating oil and electrical equipment designers and operators. Besides, this study would be helpful to improve the electrical characteristics of the insulating oil produced in Korea.