• Title/Summary/Keyword: 기밀성 시험

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Optimum Design on Fire Resistance of Gas Cylinder Cabinets using Thermal Analysis (열해석을 이용한 가스 실린더 캐비닛의 내화성능 최적설계)

  • Nam, Minseo;Kim, Jiyu;Kim, Euisoo
    • Journal of the Korean Institute of Gas
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    • v.26 no.1
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    • pp.34-40
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    • 2022
  • Gas cylinder cabinets have risks such as cylinder explosion and scattering of debris when a fire occurs. These risks are likely to cause gas spills and cause secondary damage. In order to reduce damage, it is very important to secure the fire resistance performance of the gas cylinder cabinet. In foreign countries, NFPA codes in the United States and EN-14470-2 in Europe stipulate fire resistance test standards for gas cylinder cabinets to protect internal cylinders for a certain period of time in a situation where gas cylinder cabinets are exposed to flames. However, in Korea, only internal pressure performance and airtight performance standards are specified, and the target is limited to piping, and research and regulations for the fire resistance performance of gas cylinder cabinets are insufficient compared to overseas. Therefore, in this study, finite element analysis was used to establish fire resistance standards for domestic gas cylinder cabinets. In the event of a fire, optimal conditions are derived in terms of structure and material.

A Web-based 'Patterns of Care Study' System for Clinical Radiation Oncology in Korea: Development, Launching, and Characteristics (우리나라 임상방사선종양을 위한 웹 기반 PCS 시스템의 개발과 특성)

  • Kim, Il Han;Chie, Eui Kyu;Oh, Do Hoon;Suh Chang-Ok;Kim, Jong Hoon;Ahn, Yong Chan;Hur, Won-Joo;Chung, Woong Ki;Choi, Doo Ho;Lee, Jae Won
    • Radiation Oncology Journal
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    • v.21 no.4
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    • pp.291-298
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    • 2003
  • Purpose: We report upon a web-based system for Patterns of Care Study (PCS) devised for Korean radiation oncology. This PCS was designed to establish standard tools for clinical quality assurance, to determine basic parameters for radiation oncology processes, to offer a solid system for cooperative clinical studies and a useful standard database for comparisons with other national databases. Materials and Methods: The system consisted of a main server with two back-ups in other locations. The program uses a Linux operating system and a MySQL database. Cancers with high frequencies in radiotherapy departments in Korea from 1998 to 1999 were chosen to have a developmental priority. Results: The web-based clinical PCS .system for radiotherapy in www.pcs.re.kr was developed in early 2003 for cancers of the breast, rectum, esophagus, larynx and lung, and for brain metastasis. The total number of PCS study items exceeded one thousand. Our PCS system features user-friendliness, double entry checking, data security, encryption, hard disc mirroring, double back-up, and statistical analysis. Alphanumeric data can be input as well as image data. In addition, programs were constructed for IRB submission, random sampling of data, and departmental structure. Conclusion: For the first time in the field of PCS, we have developed a web-based system and associated working programs. With this system, we can gather sample data in a short period and thus save, cost, effort and time. Data audits should be peformed to validate input data. We propose that this system should be considered as a standard method for PCS or similar types of data collection systems.

Nonlinear Analysis of Rubber Bellows for the High Speed Railway Vehicle (고속철도차량 갱웨이 벨로우즈의 비선형 해석)

  • Kang, Gil-Hyun;Kim, Chul-Su
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.8
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    • pp.3631-3637
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    • 2013
  • Gangway bellows in this study is the double wrinkled neoprene rubber component to accept various deviations between the carriage end parts of the articulated type high speed railway vehicle(HSRV). The fatigue failure of the bellows has a harmful effect on the riding comfort for the passengers with the increase of noise and ringing in the ears due to air-tightness failure during pass through a long tunnel. In this study, to assure the safety of gangway bellows of the HSRV, non-linear analysis of the gangway bellows considering triaxial angular displacement(rolling /yawing/pitching) between the carriage end parts are performed. The non-linear properties of the rubber are determined by uniaxial tension and equi-biaxial tension test. Moreover, from the results of non-linear analysis, the effects of the angular displacements and frictional coefficients are evaluated.

A Study on the Development of Unified Ball Valve and Polyethylene-Steel Pipe Via Virtual Manufacturing and Experimental Approach (가상생산 및 실험을 통한 폴리에틸렌관과 금속관 일체형 볼 밸브의 개발에 관한 연구)

  • Suh, Yeong-Sung;Yoo, Je-Hyuk;Ji, Min-Wuk;Song, Jeong-Hyun;Lee, Jae-Yoon
    • Journal of the Korean Institute of Gas
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    • v.14 no.1
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    • pp.47-54
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    • 2010
  • In order to reduce the number of installation processes and the cost, a unified ball valve and polyethylene-steel pipe is proposed and tested. An integrated design approach is carried out such that a virtual manufacturing based on finite-element analysis is first performed in order to examine contact conditions under exaggerated temperature variations (${\Delta}T\;=\;60^{\circ}C$ and $-50^{\circ}C$ for summer and winter, respectively). From the final design configuration, it was predicted that the maximum contact pressures are 71 and 8.1 MPa for summer and winter, respectively, at relatively larger contact surface. Based on this observation, a prototype model is fabricated to go through an actual leakage test. The prototype pipe passed a hydrostatic strength test successfully, showing no leakage at even much higher (54 MPa) than the operational pressure (0.25 MPa).

An Experimental Study on Performance of Heatproof Silicon at the Connector of Boiler Exhaust Tube (배기통과 가스보일러 접속부의 내열실리콘 성능에 관한 실험적 연구)

  • Leem, Sa-Hwan;Lee, Jong-Rark;Kim, Cheol-Jin;Han, Gwi-Ho;Kim, Yong-Joo;Kim, Hee-Soo;Jang, Won-Suk;Lim, Cheong-Hwan
    • Journal of the Korean Institute of Gas
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    • v.11 no.4
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    • pp.91-97
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    • 2007
  • Recently, during the past five years, accidents of gas boiler using city gas have occurred 7.4 times more than those which use LP gas. The number of accidents has increased since the use of city gas boilers has increased. These boiler accidents resulted in 87% death from poisoning of CO, and casualty of the accidents was 4.3 times more than that of other types of accident. Hence this study makes the cause of accidents clear by separation the exhaust tube which is the cause of CO poisoning. Also, this study will establish the safety of heat-resistant silicon through testing the performance of heat-resistant silicon. The experiment showed that common silicon started hardening at $56^{\circ}C$ while the heat-resistant silicon did not begin carbonization until $606^{\circ}C$. Besides at the temperature of $150^{\circ}C$ which is the normal temperature of exhaust tube, common silicon leaked on the pneumatic test after deterioration, but the heat-resistant silicon maintained its original property. With these results, we judge that we can reduce the casualty by CO poisoning if we use the heat-resistant silicon to the connector of he exhaust tube.

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