• 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.

• Journal of Chest Surgery
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• v.24 no.10
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• pp.1039-1043
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• 1991

The bullectomy, or sedge resection of the lung including bullae is the treatment of choice for the recurrent spontaneous pneumothorax, and but results in pleuropulmonary fistulae in postoperative periods in some emphysematous lungs. There are many methods to close the air leakages with T-M, Talc powders. Or the closure of air leakage sites can be closed c resuture, wedge resection or lobectomy through re-explothoracotomy. Tisseel, a in thoracic surgical areas in recents. We have sealed the post-operative air leakage sites after bullectomy or segmental resection for 4 recurrent spontaneous pneumothorax with the spray of Tisseel & throbin through thoracoscope without re-explothoracotomy. The post-operative courses are uneventful to now.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2011.11a
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• pp.310-313
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• 2011

국내에서 고층건물의 제연시스템으로 급기가압 제연시스템이 일반적으로 사용되고 있는데, 기존의 급기가압 제연시스템의 설계방안과 같이 한개의 급기풍도를 통해 누설량과 보충량이 동시에 공급될 경우에는 부속실과 옥내간에 형성되는 차압이 설계기준에 미달하거나 과압이 될 가능성이 매우 높아져서 급기가압 제연시스템의 설치목적을 달성하지 못할 수 있다. 이에 대한 개선방안으로 본 연구에서는 누설량의 공급과 보충량의 공급을 각기 다른 유로를 통해 수행하는 방안 및 장치구성을 제시함으로서 고층건물에서 화재 발생시 안전한 피난환경을 제공하고자 한다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2006.06a
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• pp.513-514
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• 2006

This paper presents the temperature characteristics with the structure of 18 kV surge arresters for distribution system. Three types of polymer arrester were fabricated and a ceramic arrester was also prepared to investigate. Below $100^{\circ}C$, three types of polymeric arresters exhibited almost the same leakage current value, but above $100^{\circ}C$, the polymeric arresters whose module was injected into polymeric housing with the grease exhibited the highest leakage current. In contrary, the arresters being manufactured by directly injecting silicone rubber onto arrester module exhibited the lowest leakage current. The rapid rising of leakage current of the polymeric arresters with the grease at $120^{\circ}C$ was because of the deterioration of the insulation characteristics of the grease between the FRP module and the silicone housing. All polymeric arresters exhibited the same surface temperature characteristics but the ceramic arresters was slower than the polymer arrester in heat emission despite the lowest leakage current. It was thought that the air layer between ZnO varistor blocks and the ceramic housing prevented the heat emission.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.8
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• pp.780-788
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• 2005

Two different types of algorithms were developed and applied to detect the partial faults of a multi-type air conditioning system. Partial faults include the compressor valve leakage, the refrigerant pipe partial blockage, the condenser fouling, and the evaporator fouling. The first algorithm was developed by using mathematical models and parity relations, and the second algorithm was developed by using mathematical models and a RBF neural network. Test results showed that the second algorithm was better than the first algorithm in detecting various partial faults of the system. Therefore, the algorithm developed by using mathematical models and a RBF neural network may be used for the detection of partial faults of an air-conditioning system.

• 유체기계공업학회:학술대회논문집
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• 2003.12a
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• pp.143-148
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• 2003

This study was experimentally performed in order to estimate the errors due to the leakage of transmitter gaugelines in the orifice flow meter for natural gas. It would be a serious problem in safety if a large quantity of leak was occurred at the tubes or fittings like valve. But in most cases the safety problems might be rarely happened because the gas leak detectors could be operated in advance and the various kinds of inspection would be also fulfilled periodically. If the leakage was occurred continuously with an undetectable amount at the gaugelines for measuring the pressure or the differential pressure(DP), the amount of leakage might be an error or an unaccounted flow(UAE). In addition if the measuring value of pressure or DP were affected by the leakage, it might also be a measurement error. The experiments were performed to estimate the amount of leakage and to check the DP changes if it exited. First, through the measurement of the air pressure changes in the airtight container connected to a transmitter with gaugelines as the time passed, the amount of leakage causing from the fittings of gaugelines was roughly estimated. As changing the leak position of the gaugeline, the leak was intentionally made to break out. The variance of DP was checked as controlling the extent of leakage and compared to no leak conditions. Consequently, under the normal maintenance conditions, the result represented that the amount of leakage causing from the gaugelines was insignificant and also the DP changes on leakage conditions were too small to cause the errors of measurements.

• Proceedings of the SAREK Conference
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• 2003.07a
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• pp.172-172
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• 2003

• Journal of Environmental Health Sciences
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• v.40 no.1
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• pp.27-37
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• 2014

Objectives: On September 27, 2012, leakage of anhydrous hydrofluoric acid occurred in a chemical plant in the Gumi National Industrial Complex. Following the accident, local factory workers and residents complained of abnormal health conditions. In addition, visual discolorations were widely observed in crops and trees in surrounding areas. The main objectives of the present study were to identify the area that was affected by the spill using data obtained from plants, soil, and water samples after the accident. Methods: Fluoride concentrations were analyzed in pine tree needles, soil, nearby streams, ponds and reservoirs collected from an area within a radius of three kilometers from the plant where the leak occurred. Fluoride concentrations in the air at the time of leakage were then estimated from fluoride concentrations that were measured in the pine tree needles. A Kriged map was developed to describe the spatial distribution of hydrofluoric acid at the time of the leakage and was compared with the area designated as a Special Disaster Zone by the government. Results: The Special Disaster Zone did not include all the affected area that was estimated by the Kriged map. Analytical results of the environmental samples also supported this discrepancy. Conclusion: Using plants, atmospheric concentrations of fluoride at the time of the leakage could be estimated. For the area that was identified as affected, further public health risk assessment and environmental risk assessment should be considered. Also, in the absence of air monitoring at the time of leakage, studies employing plants may be conducted in order to better understand the spatial extent and severity of the contamination.

• Imaging Science in Dentistry
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• v.37 no.2
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• pp.65-68
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• 2007

Purpose: To compare the leakage and scattered radiation from hand-held dental X-ray unit with radiation from fixed dental X-ray unit. Materials and Methods: For evaluation we used one hand-held dental X-ray unit and Oramatic 558 (Trophy Radiologie, France), a fixed dental X-ray unit. Doses were measured with Unfors Multi-O-Meter 512L at the right and left hand levels of X-ray tube head part for the scattered and leakage radiation when human skull DXTTR III was exposed to both dental X-ray units. And for the leakage radiation only, doses were measured at the immediately right, left, superior and posterior side of the tube head part when air was exposed. Exposure parameters of handheld dental X-ray unit were 70 kVp, 3 mA, 0.1 second, and of fixed X-ray unit 70 kVp, 8 mA, 0.45 second. Results: The mean dose at the hand level when human skull DXTTR III was exposed with portable X-ray unit $6.39{\mu}Gy$, and the mean dose with fixed X-ray unit $3.03{\mu}Gy$ (p<0.001). The mean dose at the immediate side of the tube head part when air was exposed with portable X-ray unit was $2.97{\mu}Gy$ and with fixed X-ray unit the mean dose was $0.68{\mu}Gy$ (p<0.01). Conclusions: The leakage and scattered radiation from hand-held dental radiography was greater than from fixed dental radiography.

• Journal of the Architectural Institute of Korea Structure & Construction
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• v.34 no.1
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• pp.61-68
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• 2018

Recently, concentration of fine and ultra-fine particulate matter(PM) has been increased in KOREA. The increase of PM in KOREA is due to increase of domestic industries and yellow dust from china. PM is known to cause diseases such as dyspnoea, asthma, arrhythmia. Since PM is harmful to human, KOREA Ministry of Environment(ME) warns people to stay indoors when the outdoor PM concentration is high. However, prior studies has shown that indoor PM concentration can be relatively high when outdoor PM concentration is high due to infiltration of PM into buildings though leakage areas. In this study, airtightness, indoor and outdoor pressure difference and PM 2.5 & 10 concentration were measured in an apartment complex to observe PM infiltrating into building. Field measurement was conducted in newly-built apartment buildings to avoid the influence of indoor PM which can be generated by residents. The airtightness test was conducted to identify the leakage areas of the apartment, such as electric outlets and supply/exhaust diffusers. The airtightness test result showed that the air leakage area of the building was dominant in buildings envelop. According to indoor and outdoor pressure difference measurement result and PM concentration measurement result, it can be concluded that outdoor PM can infiltrate into indoor by leakage areas when wind is blown toward the apartment. As a result, pressure difference formed by the external weather condition and architectural characteristics such as the airtightness in building can influence PM to infiltrate into buildings. In further studies, I/O ratio, stack-effect, infiltration and penetration factor will be considered.