• Proceedings of the KIEE Conference
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• 2000.07e
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• pp.22-25
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• 2000

Time dependent ozone generation characteristics of some oxide layers grown by ozone on the surface of corona discharge wires have been investigated experimentally in air ambience. Four wires of stainless steel, iron, silver and copper were used for the corona discharge wire of an ozone generator. And the effect of the metal oxide layers on ozone generation was studied and the contamination morphology of each layers was characterized. With the SEM images and the EDS spectra, it was found that all the surface of the corona wire were oxidized by the generated ozone and contaminated by airborne particles through the gradient force. As a result, the morphology and the electrical property of metal oxide layer grown on corona wire surface influenced on ozone generation characteristics i.e. discharge mechanisms.

• 전자공학회논문지 IE
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• v.46 no.3
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• pp.26-32
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• 2009

The reason of the contamination in the VLSI industry is the electric charge of the wafer itself. We develop the corona discharged system of clearing static electricity with a fan. This system has automatic cleaner of discharging electrode, check the state of jot control a suitable mount of discharged ion, and monitor all state using Zigbee communication module.

• Plant Journal
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• v.7 no.2
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• pp.30-38
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• 2011

The purpose of this paper is to review the understanding of pollution causes in the excitation system and how to solve the problem. The cause of the problem was in-leakage of bearing lubricant oil through the gap between rotor and outer in the air deflector, which was triggered by a negative pressure with respect to the operation of a collector ring fan in the collector house. In order to prevent exciting current transmission equipment pollutant, the reduction of the negative gage pressure of the inside of collector house is required. The protection in-leakage of bearing lubricant oil through the gap between rotor and outer of the air deflector are necessary. The reduction of the inside diameter of air deflector and the expansion of inlet filter of collector house are inevitable.

• Proceedings of the KIEE Conference
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• 1999.07e
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• pp.2364-2367
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• 1999

Polymer insulating materials are widely used in power distribution and transmission systems for their good dielectric properties, light weight, low cost, and good contamination performance. Tracking is one of the biggest problems to be overcome in polymer insulating materials. The alumina trihydrate(ATH) is widely used as a filler for improve the tracking performance of silicone rubber. In this paper, we have investigated the influence of surface treatment of fillers on the tracking performance of silicone insulator using the IEC 587 tracking test method.

• 한국정보디스플레이학회:학술대회논문집
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• 2009.10a
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• pp.173-176
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• 2009

We suggest a new protective layer for PDP consists of SrO and MgO double layer. This double layer structure protects SrO layer from the contamination by $H_2O$ or $CO_2$ in the air and enable SrO to play as the main cathode material. It was confirmed that the high secondary electron emission characteristics of SrO by Xe ion can bring considerable driving voltage reduction and improvement of luminance and luminous efficacy in PDP.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2013.05a
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• pp.33-34
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• 2013

Recently, as the policy of state that it is the low carbon green growth is promoted, the effort for reducing the CO₂ gas generation ejected from the construction industry in the cement production is continued. That is, the method using the mineral admixtures including the silica fume and red mud, silica fume and etc. it is the industrial byproduct with the method solving the exhaustion problem of the environmental contamination settlement and natural resources, the great quantity as the cement substitute material is examined. Accordingly, in this research, the strength characteristic of the curing body differentiating the curing method of the ternary system inorganic binder using the blast furnace slag and red mud, silica fume and etc. as the cement substitute material tried to be examined.

• Journal of the Korean institute of surface engineering
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• v.52 no.5
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• pp.239-245
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• 2019

To increase the throughput of tip-based nanolithography (TBN), one approach is to use a large array of such tips working in parallel. It is important to maintain co-planarity between the tip array and the writing surface. A slight misalignment can cause large discrepancies of contact force and feature sizes. We report a capacitive proximity sensor built-in with the TBN array for leveling an arrayed polymer pen array. The device allows alignment between an array of writing tips and the writing substrate without contact and contamination. The angular sensitivity of the sensor is $0.05^{\circ}$ for an array with maximum tip-to-tip separation of 100 mm.

• Journal of the Semiconductor & Display Technology
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• v.18 no.4
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• pp.62-68
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• 2019

The optoelectronic display units such as TFT-LCD or OLED require many thin optical plastic films and their mass manufacturing processes employ CO2 laser cutting of those thin films in a large quantity. However, laser film cutting could generate fume particles through melt shearing, vaporization, and chemical degradation and those particles could be of great concern for film surface contamination. In order to appreciate the fume particle dispersion behaviors in laser film cutting, this study relies on random particle simulations by probabilistic distributions of particle size, ejection velocity and angles coupled with Basset-Boussinesq-Oseen model of particle trajectory in low Reynolds number flows. Here, up to one million particles of random sampling have been tested to effectively show fume particles dispersed on the film surface. The computational results could show that particular range of fume particle size could easily disperse into the pixel region of processed optical films.

• International Journal of Korean Welding Society
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• v.1 no.2
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• pp.1-6
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• 2001

A weld quality assessment method is proposed in this work, which can be applied to the short-circuit mode in GMAW. Information about the welding signal trajectory, distribution of the signal duration at each sub-regions and short-circuit frequency is used to evaluate the weld quality. The weighted penalty, which is determined experimentally, is imposed for each abnormal signal. Performance of the proposed method is compared with the Simpson's method under the conditions of shielding gas reduction, workpiece surface contamination and joint gap in the butt and fillet welds. Although the proposed method predicts the weld quality with reasonable accuracy, further modification and extension to other metal transfer modes are needed as a further study.

• Journal of Environmental Science International
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• v.16 no.5
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• pp.657-664
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• 2007

The content and distribution of some heavy metals (Fe, Mn, Cr, Co, Cu, Ni, Zn and Pb) were investigated in the <$63{\mu}m$ bed sediments of the Mangyeong river to recognize the extent of contamination. Results showed that a wide range of concentrations was apparent for every metal. These variations were particularly significant at the confluence of tributaries. High levels of metals occur mainly in the confluence of tributaries. Geoaccumulation indexes have been calculated to assess whether the concentration observed represent background or contaminated levels. It is proved that the Mangyeong River is moderately to strongly polluted for Mn, Cr, Cu, Zn and Pb. The spatial extent of pollution was examined, and it was found that the most polluted area is located in the confluence of Iksan and Jeonju tributaries.