• Title/Summary/Keyword: Cause of failure

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A Case of Acute Renal Failure Caused by Rhabdomyolysis due to Hyperosmolar Nonketotic Coma in Children (소아의 고삼투압성 비케톤성 혼수에서 발생한 횡문근 융해증에 의한 급성 신부전 1례)

  • Kwak, Jeong Won;Oh, Jae Min;Kim, Su Yung
    • Clinical and Experimental Pediatrics
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    • v.48 no.5
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    • pp.565-568
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    • 2005
  • Hyperosmolar nonketotic coma complicated in diabetes mellitus has been a rare cause of rhabdomyolysis, although increasingly reported recently. Acute renal failure can be complicated in 15 percent of rhabdomyolysis patients, but is rare in the case of rhabdomyolysis caused by diabetic hyperosomolar nonketotic coma. We report a 14 years-old boy with acute renal failure complicated by rhabdomyolysis caused by diabetic hyperosmolar coma.

Reliability Evaluation of a Slurry Pump (슬러리 펌프의 신뢰성 향상)

  • Jung, Dong Soo
    • Journal of Applied Reliability
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    • v.16 no.4
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    • pp.263-271
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    • 2016
  • Purpose: A slurry pump for flue gas desulfurization system performs a role that discharges the slurry of a plaster shape in a thermal power plant. Since a slurry pump transfers the slurry by the centrifugal force, it has the friction wear in the impeller and liner because of the slurry. Methods: In this study, failure analysis and test evaluation on the slurry pump have been proposed and the process that reliability of the product improves through design improvement has been presented. And failure cause of typical failure case has been investigated and improvement design has been presented. Results: Reliability improvement is established by analysis of the test results of before and after acceleration test. Conclusion: This study can be provided to improve the product reliability through failure analysis of a slurry pump.

Life Analysis of Pneumatic Valve (공기압 밸브의 수명 분석)

  • Kang, Bo-Sik;Lee, Seung-Hun;Kim, Kyung-Soo;Lim, Nam-Gu;Kim, Hyoung-Eui
    • Proceedings of the KSME Conference
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    • 2007.05a
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    • pp.1848-1853
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    • 2007
  • In this study, we are to analyze the life and the main failure mode of pneumatic valves that are usually applied to the factory automation line. Pneumatic valves have complicated failure cause since they are organized as a complex of various elements. Therefore, in this paper, we analyzed the main failure mode of pneumatic valves, and then performed life test and performance test according to the international standards. On the basis of these processes, we estimated a shape parameter that is the main factor for the calculation of test time for the reliability of pneumatic valves by analyzing life distribution data.

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Flashover Failure of Polymer Insulator in Distribution Lines (배전용 폴리머애자의 섬락고장)

  • 한재홍;이병성;김찬영;윤태상
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2000.07a
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    • pp.767-770
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    • 2000
  • This study was investigated for searching a cause of flashover failure of polymer insulator and preparing countermeasures. Hydrophobicity, microstructure and chemical structural change of polymer weathershed were studied by polymer characterization methods. In addition, the electrical properties such as power frequency dry flashover voltage/impulse voltage tests, contamination characteristics were carried out. The hydrophobicity of polymer weathershed was decreased significantly and cracks were observed on the surface. Also, the electrical characteristics did not satisfy the KEPCO specification. The failed polymer insulators showed the more leakage current than 4 years service-aged ones. From the result, it can be concluded that the flashover failure of polymer insulator was attributed to the surface aging and severe contamination.

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Immunogenicity of botulinum toxin

  • Wee, Syeo Young;Park, Eun Soo
    • Archives of Plastic Surgery
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    • v.49 no.1
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    • pp.12-18
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    • 2022
  • Botulinum toxin treatment is the most common non-surgical cosmetic treatment. Although there are many available treatments using botulinum toxin, their effects are temporary and repeated injections are required. These frequent injections can trigger an immunological response. In addition, botulinum toxin acts as an antigen in the body; thus, its effect disappears progressively due to this immunological reaction, which may cause treatment failure. Active botulinum toxin consists of a core neurotoxin and complexing proteins, the exact effects of which remain unclear. However, the complexing proteins are closely related to the immune response and the formation of neutralizing antibodies. Since neutralizing antibodies can lead to treatment failure, their formation should be prevented. Furthermore, various methods of detecting neutralizing antibodies have been used to predict treatment failure.

A case study of slope failure for large cut-slope (대절토사면내 붕괴발생에 따른 안정성검토 사례연구)

  • Lee, Yeon-Hee;Shin, Chang-Gun;Kim, Yong-Soo;Han, Jae-Hee;Choi, Jun-Il
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.697-702
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    • 2006
  • A counterplan of slope failure has to investigate about various and engineering safety factors. Especially, it is important that large cut-slope must examine rational and economic solution. In this case study, cut-slope failure caused by inflow of rainwater into alternate layers. Hereafter it is suggested that large cut-slope should consider analysis the cause for a decline of safety factor and the engineering character of corestone ground mass.

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Premature Failure of Deep Grooved Ball Bearing for Automobiles : Part 2 - Critical Dent Size (자동차용 깊은홈 볼베어링의 조기파손 : 2보 - 임계압흔의 크기)

  • Hyun Joons;Park Tae Jo
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2003.11a
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    • pp.395-401
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    • 2003
  • In this paper, the dent printing phenomena and critical dent size which lead to premature failure of deep grooved ball bearing for automobiles are presented. The results of newly assembled test bearings showed that the ball dent size strongly affect the bearing life and inner ring raceways were the major failed parts in spite of using the dented balls. The dent printing phenomena are a root cause of premature failure, which was not reported until now. And there exist the critical ball dent size for given rolling bearings and operating conditions. So, the initial condition of tribologically mating parts should be treated as important as the failed body itself.

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A Study on the Rolling Bearing Failure Mode of Automotive Transmission(I) (자동차 변속기용 구름베어링의 파손현상 고찰(I))

  • 현준수;문호근;박태조
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2001.06a
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    • pp.406-411
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    • 2001
  • This paper shows the failure(wear) phenomena of automotive transmission bearings and investigate their characteristics. It was found that the wear mechanism was mainly abrasive wear by the presence of particles in the gear box and the balls was weared more severely than the other tribological contacting parts. The wear of balls alter the bearing contact angle and load ratings, and finally it cause the bearing failure. With close examination of the failed bearing, various countermeasures could be suggested.

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Statistical Life Expectancy Calculation of MV Cables and Application Methods (중전압 전선의 통계적 수명예측 계산과 응용 방법)

  • Chong-Eun, Cho;On-You, Lee;Sang-Bong, Kim;Kang-Sik, Kim
    • KEPCO Journal on Electric Power and Energy
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    • v.8 no.2
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    • pp.61-68
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    • 2022
  • In this paper, the change history of various types of MV (Medium Voltage) cables was investigated. In addition, the statistical life expectancy of each type was calculated by using the operation data and the failure data. For cut-off year, 10 years was applied, and realistically applicable statistical life expectancy was calculated by correcting the cause of failure entered by mistake. The life expectancy of FR-CNCO-W was calculated as 51.2 years, CNCV-W 38.1 years, and CNCV 31.4 years and the overall average is 33.8 years. Currently, the life expectancy of TR CNCV-W is 29.4 years, but it is estimated that the lifespan will be extended if failure data is accumulated. As a result, it is expected that life expectancy results can be applied to Asset Management System (AMS) in the future.

Failure of Hydraulic Oil Pipe and Transient Vibration (압유배관의 절손 원인 규명과 과도진동)

  • Kim, Yeon-Whan;Lee, Young-Shin;Koo, Jae-Raeyang;Kim, Hee-Su;Bae, Yong-Chae;Lee, Hyun
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1268-1273
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    • 2003
  • This paper presents a case history of piping failures on power plant. The root cause of the failure was defined to set the optimal countermeasures. The failure comes from transient vibration and the 1st stress increased at the hydraulic oil supply system of control valves for high pressure steam turbine.

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