• Title/Summary/Keyword: 충수

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부분충수 운전중 잔열제거계통 기능상실사고에 대한 CATHARE2 코드의 민감도 분석

  • 정영종;김원석;장원표
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05b
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    • pp.48-54
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    • 1996
  • 가압경수로의 부분충수 운전중 RHR 계통의 기능상실시 사고완화를 위해 가압기 manway와 증기 발생기 출구공동 manway를 동시에 개방한 경우에 대한 실험결과를 CATHAHR2 코드를 이용하여 해석하였다. 해석을 통해 이 경우에 발생하는 물리적 현상을 이해하고 이와 같은 과도기에 대해 코드 예측능력을 평가하므로 써, 실제 원전에서 사고시 적절한 사고대응 방안을 강구하는데 참고가 될 수 있도록 해석적 근거를 제시하고자 한다. 연구결과 CATHARE2 코드는 실험을 통해 관측된 주요 물리적 현상들을 타당하게 예측하였으나, 가압기와 밀림관의 DP를 과대 예측하여 원자로 상부공동의 최대압력을 실험보다 약 7kPa 높게 예측하였다. 노심 노출시간도 노심에서 기포율 분포를 비현실적으로 예측하여 실험보다 약 500초 지연되었다. 실험과 코드의 모의결과를 통하여 노심 노출은 중력주입에 의한 냉각수 보충만으로 충분히 회복될 수 있음을 확인하였다. CATHARE2 코드는 비록 상세한 현상들에 대해 다소 불확실성을 내포하였으나, 전반적인 거동분석에는 타당한 것으로 판단된다. CATHARE 코드는 노심에서 계면 마찰력을 줄임으로써 노심의 차압을 개선할 수 있었고, guide 튜브의 위치를 고온관 중심선과 일치시켜 guide 튜브내 액체의 hold-up 기간을 개선할 수 있었으며, 가압기의 계면 마찰력을 증가시켜서 밀림관에서 "plug and clearing" 현상을 모의할 수 있었다.모의할 수 있었다.

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A multilayer Model for Dynamics of Upper and Intermediate Layer Circulation of the East Sea (동해의 상, 중층 순환 역학에 대한 다층모델)

  • 승영호;김국진
    • 한국해양학회지
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    • v.30 no.3
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    • pp.227-236
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    • 1995
  • A simple layer model based on isophcnal coordinate is applied to the East Sea to examine the dynamics of circulation. The results confirm the existing knowledge about role of inflow-outflow and wind in driving the circulation. It is found, however, that the buoyancy flux generates quite different circulation pattern; it enhances the inflow-outflow driven circulation and has a convective nature. The circulation considering all these effects resembles the schematic one presently known. In the circulation, the intermediate layer is outcropped in the north off the northern boundary, ventilated here and flows cyclonically in the northern part of basin. This water, however, does not flow southward directly because of the strong eastward (separating from the coast) current in the layer above. This water also loses its potential vorticity while traveling around the periphery of the outcropping region and is thus characterized by minimum potential vorticity in the interior of the basin.

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A Clinical Study of Acute Colonic Diverticulitis in Children (소아에서 발생한 급성 대장 게실염의 임상적 고찰)

  • Sim, Jae Hoon;Song, Keum Ho;Sim, Yun Jung;Cho, Do Jun;Kim, Dug Ha;Min, Ki Sik;Yoo, Ki Yang;Lee, Hae Ran;Lee, Kwan Seop
    • Clinical and Experimental Pediatrics
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    • v.46 no.11
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    • pp.1095-1100
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    • 2003
  • Purpose : Children with acute colonic diverticulitis(ACD), can be misdiagnosed with acute appendicitis. Methods : We reviewed 15 cases of ACD during five years, from January 1998 to June 2002 retrospectively. Results : Most patients(80%) with ACD in children presented with right lower quadrant pain. The primary diagnosis on admission was mostly acute appendicitis(87%), and all ACD in children occurred in the right colon. Fourteen patients were managed by conservative treatment including antibiotics. A follow-up study was performed in 15 patients. There were symptomatic recurrences in two patients, but no significant complication was noted. The frequency of ACD was 11.7 per 1000 acute appendicitis. Conclusion : ACD in children can mostly be cured by conservative treatment. It is prudent to choose the management through the diagnostic work up, including abdominal sonography and computed tomography, because there was no significant difference of clinical findings between ACD and acute appendicitis.

Acute Appendicitis in Children and Adolescents: Factors Associated with Perforation and the Causative Organism (소아 청소년의 급성 충수염: 천공과 연관된 인자 및 원인균)

  • Lee, Sol;Kwon, Hyuck Jin;Ahn, Soo Min;Lee, Kwan Seop;Kim, Kwang Nam
    • Pediatric Infection and Vaccine
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    • v.25 no.1
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    • pp.1-7
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    • 2018
  • Purpose: This study aimed to determine which factors are related to perforated appendicitis. We also conducted a survey to identify the causative organism. Methods: From January 2011 to December 2014, 569 pediatric patients (322 male) younger than 19 years old who underwent an appendectomy due to acute appendicitis at Hallym University Sacred Heart Hospital were enrolled. Patients' medical records were reviewed retrospectively to determine their clinical manifestations, laboratory and imaging results, and pathogens. Results: About 127 patients (22%) had perforated appendicitis. The rate of perforated appendicitis in preschool, late childhood, and adolescent ages were 50%, 27%, and 16.8%, respectively. The risk factors of perforation were high C-reactive protein levels and the presence of appendiceal fecalith (P<0.001). Of the 24 samples of peritoneal fluid and periappendiceal pus that were collected intraoperatively, 16 were culture positive. The most common pathogen was Escherichia coli (n=10), and others were Pseudomonas aeruginosa, Streptococcus spp., and Staphylococcus spp. Conclusions: The perforation rate of appendicitis among patients younger than 5 years old was 50%, and this decreased in proportion with age. Clinicians should be aware of the possibility of perforation when patients with appendicitis have high C-reactive protein levels or the presence of appendiceal fecalith on imaging.

A study on the fabrication and efficeiency enhancement of flexible Dye-Sensitized Solar Cell(DSSC) using Nano Particle Deposition System(NPDS) and UV laser treatment (나노 입자 적층 시스템과 UV 레이저를 이용한 유연기판 염료감응형 태양전지의 제작과 효율 향상에 대한 연구)

  • Choi, J.O.;Ahn, S.H.;Lee, G.Y.;Kim, C.S.;Kim, D.H.;Lee, H.T.;Park, J.I.;Lee, C.S.
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2012.05a
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    • pp.789-790
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    • 2012
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