• Title/Summary/Keyword: 증기고착

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Effect of DP Finishing Conditions on the Mechanical Properties and Hand of Cotton Fabrics (DP 가공조건이 면직물의 역학적 성질과 태에 미치는 영향)

  • 신윤숙
    • Journal of the Korean Society of Clothing and Textiles
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    • v.24 no.3
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    • pp.440-447
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    • 2000
  • The effects of DP finishing conditions including process technique and finishing agent on the mechanical properties and hand of cotton fabrics were investigated. 100% cotton fabrics were treated with NMA/DMDHEU and NMA/YF using wet-fixation and steam-fixation process. For comparison, conventional pad-dry-cure process was used with DMDHEU. After DP finishing, tensile and compressional resilience increased and bending hysteresis decreased, resulting in the improvement of dimensional stability of cotton fabric. WF and SF process rendered fabrics better shear properties, tensile energy, and compressional linearity and energy than PDC process. However, SF process produced fabrics with higher geometrical roughness than WF process. After DP finishing, primary hand values except Koshi increased, resulting in the increase of total hand value of cotton fabric.

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Removing Resin Contaminants from the Seated Stone Buddha (Korean Treasure No.84) of Sinboksa Temple Site in Gangneung (강릉 신복사지 석조보살좌상 보물 제84호 수지상 오염물 제거 방안 연구)

  • Lee, Byeonghoon;Go, Hyeongsun
    • Conservation Science in Museum
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    • v.15
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    • pp.56-65
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    • 2014
  • The face of the Seated Stone Buddha Korean Treasure No.84 of Sinboksa Templesite in Gangneung was contaminated with a glossy resin, spoiling its beauty. The contaminants covered the face, the forehead of the urna, to the bottom of the jaw. FT-IR analysis on a sample of the contaminants identified the substance as cyanoacrylate instant adhesive, which can normally be melted with acetone and removed with a swab. However, given that the surface of the statue was severely weathered from prolonged open-air exposure, alternative removal procedures were considered, to minimize the possibility of physical damage. After research, two removal procedures were utilized: one procedure involving poultices, which had been used to remove graffiti from the Samjeondobi Stele, and one procedure involving steam sterilization, which has been used to remove resin from pottery and porcelain. When both the poultices and steam sterilization were applied together, the resin was removed within twenty-four hours, without physical work using a swab.

저온 용융 합금물을 이용한 울진 1,2호기 원전 캐비티에 대한 노심용융물 고압분출 실험 연구

  • 박래준;김상백;김희동;김찬수;이규정
    • Proceedings of the Korean Nuclear Society Conference
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    • 1998.05a
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    • pp.783-788
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    • 1998
  • 국내 프랑스 가압경수형 원전인 울진 1,2호기 캐비티의 격납건물 직접가열에 대한 특성을 분석하기 위하여 노심용융물 고압분출 실험을 수행하였다. 본 연구에서는 환형통로 면적과 파손 직경에 따라 원자로용기 압력을 변화시키면서 용융물을 저온 용융 합금물인 Wood's Metal, 증기를 질소기체로 각각 모의하여 실험을 수행하였으며, 실험 결과는 물을 용융물 상사물로 사용한 전년 실험 결과(1)와 비교.분석하였다. 실험결과, 밀도가 물보다 큰 저온 용융 합금물을 사용한 경우는 물을 사용한 실험결과보다 밀도와 용융물의 벽면 고화고착 때문에 격납건물로 방출되는 용융물 양이 적게 나타났다. 물을 상사물로 사용한 경우와 같이 노심 용융물 고압분출에는 원자로 용기 파손직경이 많은 영향을 미치고 환형통로 면적은 큰 영향을 미치지 않는 것으로 나타났다. 노심용융물 고압분출 실험에 중요한 영향을 미치는 실험 상사물의 밀도와 용융물의 벽면 고화부착에 대해서는 종합적으로 분석하는 추가 연구가 필요하다.

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강제순환상실시 CANDU-6 주열수송계통의 압력천이상태 해석

  • 김영보;한상구;김선철;정종식;주경인
    • Proceedings of the Korean Nuclear Society Conference
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    • 1996.05b
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    • pp.160-165
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    • 1996
  • 중수로형 원전에서 일차측 냉각수를 순환시키는 주연수송펌프가 정상운전중 갑자기 정지하는 사고를 강제순환 상실사고라 한다. 강제순환 상실사고는 주열수송계통을 과도압력상태로 만들며, 일반적으로 펌프에 공급되는 IV등급전원 상실사고와 기계적 손상에 의한 주열수송펌프 고착사고로 분류할 수 있다. 본 논문에서는 강제순환 상실사고에 대하여 중수로계통설계의 열수력 해석코드인 SOPHT를 이용하여 주열수송계통의 과도압력상태를 해석하였다. 카나다 원자력 규제위원회(AECB)의 과압 방지조건인 R-77 요구조건에 적절한 유효트립변수를 결정하기 위한 해석이 수행되었으며, 증기발생기 오염상태와 액체방출밸브 작동여부가 고도압력상태에 미치는 영향을 고찰하여 보수적 조건을 제시하였다. 또한 위와같이 결정된 보수적 조건을 근거로 ASME 코드에 명시된 과압 한계치에 대한 만족여부와 과도압력상태에 따른 주열수송계통의 열수력학적 거동을 고찰하여 보았다. 해석결과, 강제순환상실사고시 주열수송계통은 R-77 요구조건에 적합한 원자로트립변수에 따라 안정화되었으며, 계통의 최대압력은 ASME 코드가 규정한 한계치내에 있음을 알 수 있었다.

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Evaporation Characteristics of Paired Sessile Droplets on a Heated Substrate (가열된 표면에 고착된 한 쌍의 액적 증발 특성)

  • Hyung Ju Lee;Won Yeong Hwang;Jing Hao Jin;Chang Kyoung Choi;Seong Hyuk Lee
    • Journal of ILASS-Korea
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    • v.28 no.3
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    • pp.113-118
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    • 2023
  • This study investigates the evaporation characteristics of paired sessile droplets on a heated substrate. In particular, the evaporation time and contact line behaviors were analyzed based on the droplet-to-droplet distance and substrate temperature. The contact line behavior and volume variations were visualized using the shadowgraph method. It was observed that the contact diameter and contact angle exhibited similar behavior for both single and paired droplets regardless of the droplet-to-droplet distance and substrate temperature. The paired droplets demonstrated a longer evaporation time than the single droplet due to the vapor accumulation between the droplets. Furthermore, the scaled lifetime, defined as the ratio of evaporation time between paired and single droplets, increased as the droplet-to-droplet distance decreased and decreased as the substrate temperature increased, attributed natural convection.

증거기반 창업교육: 대학 교재 분석

  • Han, Ji-Eun;Kim, Na-Yeong;Bae, Tae-Jun
    • 한국벤처창업학회:학술대회논문집
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    • 2021.11a
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    • pp.57-61
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    • 2021
  • '증거기반 교육'은 개인적 경험이나 성공 사례, 그리고 전통적인 속설보다는 과학적 연구결과와 근거가 중심이 되는 교육이다. 증거기반 창업 교육은 기존 속설과 믿음, 단편적 성공 사례로 인해 고착된 인지 편향을 완화시켜 중립적인 시각을 견지할 수 있으며, 직관과 경험을 넘어 데이터와 연구 결과에 의해 의사결정을 하는 분석적 자질을 연마하는데 기여한다. 본 논문은 현재 국내의 증기기반 창업교육의 현주소를 명확히 파악하기 위하여 1999년부터 2021년 출판된 49권의 창업교육 대학 교재를 분석하였다. 구체적으로 모든 도서의 내용을 1)창업기초, 2)비즈니스모델, 3)마케팅계획, 4)재무계획, 5)운영계획, 6)창업유형, 7)절차 및 제도의 각 7가지 기준으로 구분하고, 각각 사례, 단순통계, 변인 통계, 선행 연구의 비중을 분석하였다. 분석결과 증거의 핵심인 선행연구의 비중은 전체 교재의 총 분량 중 11.25%를 차지하는 것으로 나타났다. 이는 Charlier(2011)의 MBA 교과목 대상으로 조사한 결과와 유사한 값이다.

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Fluidelastic Instability Analysis of the U-Tube Bundle of a Recirculating Type Steam Generator (재순환식 증기발생기 U-튜브군에 대한 유체탄성 불안정 해석)

  • 조종철;이상균;김웅식;신원기;은영수
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.1
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    • pp.200-214
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    • 1993
  • This paper presents the results of fluidelastic instability analysis performed for the U-tube bundle of a Westinghouse model 51 steam generator, one of the recirculating types designed at an early stage, in which the principal region of external cross-flow is associated with the U-bend portion of tube. The prerequisites for this analysis are detailed informations of the secondary side flow conditions in the steam generator and the free vibration behaviours of the U-tubes. In this study, the three-dimensional two-phase flow field in the steam generator has been calculated employing the ATHOS3 steam generator two-phase flow code and the ANSYS engineering analysis code has been used to calculate the free vibration responses of specific U tubes under consideration. The assessment of the potential instability for the suspect U-tubes, which is the final analysis process of the present work, has been accomplished by combining the secondary side velocity and density distributions obtained from the ATHOS3 prediction with the relative modal displacement and natural frequency data calculated using the ANSYS code. The damping of tubes in two-phase flow has been deduced from the existing experimental data by taking into account the secondary side void fraction effect. In operation of the steam generator, the tube support conditions at the tube-to-tube support plate intersections due to either tube denting degradation or deposition of tube support plate corrosion products or ingression of dregs. Thus, various hypothetical cases regarding the tube support conditions at the tube-to-tube support plate intersections have been considered to investigate the clamped support effects on the forced vibration response of the tube. Also, the effect of anti-vibration bars support in the curved portion of tube has been examined.

Development of TASS Code for Non-LOCA Safety Analysis Licensing Application (Non-LOCA 인허가 해석용 TASS 코드의 개발)

  • Yoon, Han-Young;Auh, Geun-Sun;Kim, Hee-Cheol;Kim, Joon-Sung;Park, Jae-Don
    • Nuclear Engineering and Technology
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    • v.27 no.1
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    • pp.53-66
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    • 1995
  • Since the current licensed system codes for Non-LOCA safety analysis are applicable only for a specific type PWR, it is necessary to develope a new system analysis code applicable for all apes of PWRs. As a R&D program, KAERI is developing TASS code as an interactive and faster-than-real-time code for the NSSS transient simulation of both CE and Westinghouse plane. It is flexible tool for PWR analysis which gives the user complete control over the simulation through convenient input and output options. In this paper the code applicability to Westinghouse ape plants was verified by comparing the TASS prediction to plant data of loss of AC power and loss of load transients, and comparing to the prediction of RELAP5/MOD3 for feedline break, locked rotor, steam generator tube rupture and steam line break accidents.

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