• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2001.11a
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• pp.61-66
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• 2001

가스 공정에서 취급하는 가연성물질의 연소 특성 파악은 공정의 안전 확보에 가장 중요한 문제이다. 따라서 연소특성들은 가연성물질이 공정의 취급상 부주의로 인해 누출되어 주위에 공기와 혼합되면 화재 및 폭발이 발생할 수 있는 잠재적 위험성을 평가할 수 있다. 연소특성들로는 폭발한계, 인화점, 최소자연발화점, 최소산소농도, 최소발화에너지, 연소열 등을 들 수 있다/sup 1)/.(중략)

• Journal of the Korean Institute of Gas
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• v.5 no.2 s.14
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• pp.36-42
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• 2001

A leak of fuel gas in partially confined area creates a flammable atmosphere and give rise to an explosion, which is one of the most common accident in domestic. Observations from accident in domestic suggest that some explosions are caused by a quantify of fuel significantly less than lower explosion limit(LEL) amount required to fill the room, which is attributed to inhomogeneous mixing of leaked gas. The minimum amount of leaked gas for explosion is highly dependent on the mixing degree in the area. For lighter gas, such as methane, a high concentration tends to build up in the space from ceiling of room. But heavy gas, such as propane, a high concentration tends to build up in the space from bottom of room. This paper presents a method for analysing the explosion hazard in a room with very small amount of leaked gas. Based on explosion limit concentration, the gaussian distribution model is used to estimate the minimum amount of leak which yields a specified explosion pressure. The results demonstrate that catastrophic structural damage can be achieved with a volume of fuel gas which is less than 0.5 percent of the total enclosed volume in domestic. The method will help analyzing hazard to develop new safe device as well as investigating accident.

• Journal of the Korean Institute of Gas
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• v.17 no.1
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• pp.56-66
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• 2013

The gas production plants supply the inert gas to production plants for maintaining safe operation and also supply combustible, flammable, explosive and toxic gases as functions of basic materials needed for producing chemical goods. In addition, gas plants need to be safe and reliable operation because they are operated under high temperature, high pressure, cryogenic and catalytic reactions. As these plants have a complex process in operation, there has been a risk that major industrial accidents such as a fire, explosion and toxic gas released, also risks of asphyxiations by inert gases and burns caused by high temperature and cryogenic substances. This study is to carry out the semi quantitative risk assesment method which is the generic risk analysis (GRA). This method is applied to air separation unit(ASU) to identify its initial risk, safety barriers, residual risk and elements important for safety(EIS). The result of this study, suggested the management tools and procedures of implementation for EIS management.

• Journal of Chest Surgery
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• v.32 no.1
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• pp.38-42
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• 1999

Background: In neonatal respiratory distress syndrome patients, various types of pulmonary air leak contributes to elevate morbity and mortality. Although early surgical interventions can provide better results in several cases, whole clinical outcomes are poor. This study was designed to investigate the clinical aspects of pulmonary air leak in the neonatal respiratory distress syndrome patients and major contributing factors to mortality. Material and Method : We retrospectively evaluated 48 cases of pulmonary air leak in the neonatal respiratory distress syndrome patients from September 1994 to May 1997. Result: There were 15 cases of primary and 33 cases of secondary pulmonary air leakages. The prominent manifestations were pure interstitial emphysema in 19 cases(39.9%) and combined pneumothorax in 19 cases(39.9%). In clinical aspects, normal birth weight was dominant(83.4%), the onset occurred within 24 hours was in 28 cases(58.8%). The pulmonary diseases were meconium aspiration syndrome(25.2%) and hyaline membrane disease(33.2%). The overall hospital mortality was 25.2%, and the majority were hyaline membrane diseases. Conclusion: Although the overral mortality rate of these diseases were high, more detailed studies about immediate treatement, perinatal prevention, intensive care to geriatric problems were needed individually to improve outcomes.

• Journal of Chest Surgery
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• v.29 no.10
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• pp.1133-1137
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• 1996

From September 1994 to October 1995, we are reporting clinical results of 67 patients whom underwent video-assisted trio rabic surgery(VATS). 1. They were diagnosed as spontaneous pneumothorax In )5, diffuse interstitial lung disease in 9, empyema in 7, hemothorax in 5, malignant pleural effusion in 3, hyperhidrosis in 3, foreign body in chest cavity in 2, mesothelioma in 1, miliary tuberculosis in 1 and organizing pneumonia in 12. In pneumothorax, bullectomy in 33 and open bellectoiny in 2 due to pleural adhesion was done Hemostasis in 5, irrigation in 7, foreign body removal in 2, talcum powder insufrlation in 3, sympathectomy 3 as done. Thoracoscopic biopsy watt done In 12 3. For pneumothorax, operation was indicated as recurrent pneumothorax in 18, persistent air leak in 12, visible bullae In chest X-ray in 5. 4 Thoracoscopic biopsy was done in 12. They were interstitial pulmonary fibrosis in 9, miliary tuberculosis in 1, mesothelioma in 1, and organizing pneumonia in 1 .Among interstitial pulmonary fibrosis, usual interstitial pneumonia were 2 and diffuse interstitial pneumonia were 7. 5. Wo complication was found in 6) patients among 67 patients. The complication was found in 4 patients (2 persistent air leak, 2 contralateral lung atelectasis). We concluded that VATS was safe and beneficial in reducing postoperative complication and the role of thoracic surgery will increase markefdly.

• Proceedings of the Korean Society of Propulsion Engineers Conference
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• 2009.11a
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• pp.246-249
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• 2009

Test and launch facilities which use oxygen as the propellant of a launch vehicle have hazards of fire and explosion by the leakage of oxygen. Also, the personnel operating the facilities, which use the high-pressured gases like nitrogen and helium in the closed room, is exposed to the hazard of death from suffocation. Consequently, we should keep out of the hazards and the accidents by monitoring the contents of oxygen in the air. The method and the system construction for monitoring oxygen contents in the air and the results from its application to Naro space center are described on this paper.

• Journal of Environmental Impact Assessment
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• v.11 no.1
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• pp.13-23
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• 2002

본 연구에서는 침출수를 비롯한 매립지의 각종 오염물질 배출로 수자원이 오염되어 피폭체의 피해가 빈발하는 문제를 해결하기 위해서, 매립지의 상대적 유해성을 평가하여 한정된 환경관리 예산의 합리적 배분을 위한 우선순위를 결정할 수 있는 의사결정 지원도구로서 LHR(Landfill Site Hazard Ranking)모형을 개발했다. LHR모형은 다요소의사결정(多要素意思決) 기법에 정성적 위해성(危害性) 평가기법을 접맥시켜 주관적 가중치를 모형에 반영한 가치내재화(價値內在化) 모형이다. LHR모형은 피폭체의 주요 피폭경로를 지하수 이동경로와 지표수 이동경로로 보았으며, 각 이동경로별로 누출 가능성, 폐기물 특성 및 피폭체 특성으로 요소범주를 3종류로 구분하여 폐기물의 독성이나 매립량같은 특성이 매립지의 수리지질학적 요소 및 자연지리적 요소에 의해 결정되는 오염물질의 누출 가능성을 통해 매립지 주변의 지역주민과 취약한 수생태계 같은 피폭체에 끼치는 매립지의 유해성을 상대적으로 평가했다. 그리고 LHR모형에서는 매립지 유해성을 공기 이동경로 및 사회경제적 측면에서도 평가하기 위해 매립지 이격거리별 토지이용 형태의 유해성을 평가했다. 그리고 각 평가요소별 가중치는 위계분석과정(位階分析過程)의 쌍대비교법(雙對比較法)에 의하여 할당했으며, 민감도 분석으로 LHR모형을 검증했다.

• Tunnel and Underground Space
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• v.20 no.6
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• pp.446-454
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• 2010

CAES-G/T (Compressed Air Energy Storage - Gas Turbine) power generation is a likely option for the buffer facility stabilizing the fluctuation of the renewable powers, such as wind and solar powers. Considering the geological conditions, the underground CAES facility is most probable if the CAES-G/T generation is planed in Korea. In this kind of facility, a concrete plug is installed to seal the compressed air in the container, so that the selection of the shape and dimension of concrete plug could be a critical design factor. The stability evaluation of two types of plug was carried out by investigating the distribution of the factor of safety in the plugs and the distribution of contact pressure over the contact surface. The analysis result shows that the taper-shaped plug is more structurally stable than the wedge-shaped plug for the given geological condition. Possible separation of the rock-concrete interface around the spring line of the wedge-shaped plug is anticipated, which means the possible leakage of compressed air through the side wall and also means the poor mobilization of frictional resistance on that area.

• Journal of the Korean Institute of Gas
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• v.22 no.3
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• pp.38-44
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• 2018

Ammonia is used primarily as a refrigerant in refrigeration facility and SCR of a plant, and is frequently involved in leakage accidents. This study was conducted by selecting ammonia, a material with a wide influence range when evaluated, as a material with higher vapor pressure and lighter than air. In this study, the influence ranges were computed using KORA(Korea Off-site Risk Assessment supporting tool) with four different environmental factors : ground roughness, sealing, operating temperature, pressure, and leakage hole size. As a result, the difference in the influence range of ground roughness is approximately 4.62 times, while the ammonia storage tank shows a difference in the reduction rate of 0.64 when sealed. The extent of impact increased with increasing leakage depending on storage temperature and pressure, and when storing higher than the saturation vapor pressure, the impact range showed an average growth rate of 3.45 % per 0.1 Mpa($45^{\circ}C$). The influence ranges based on the size of the leakage holes is shown to be proportional to the area of the leakage zone.

• Journal of Chest Surgery
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• v.30 no.5
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• pp.512-516
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• 1997

We have experienced 66 cases of video assisted thoracic surgery(VATS) of spontaneous pneumothorax. The patients ranged in age from 1 Syears to 46years(mean age, 22.3years) and male patients were sixty three. The indications of video assisted thoracic surgery of spontaneous pneumothorax were recurrence, continuous air leakage, visible blabs on the chest X-ray & others. Infraoperative findings were as follows; blabs, pleural adhesion and pleural effusion. The operation was performed under general anesthesia wit double lumen endobronchial tube. Operative procedures included blebectomy and/or wedge resection of lung, vibramycin Pleurodesis with mechanical abrasion. In most cases, postoperative courses were uneventful and patients were discharged without significant complications. VATS provided the benefits of lesser postoperative pain, rapid recovery, short hospitalization, and smaller scar of wound. Conclusively VATS is a new interesting modality of surgical treatment of spontaneous pneumothorax and also can be extensively applicable in the diagnosis and treatment of other intrathoracic disease.