• 제목/요약/키워드: Sacrificial Material

검색결과 61건 처리시간 0.021초

노심 용융물 제트 충돌에 의한 희생물질의 침식예측 (Prediction of sacrificial material ablation rate by corium jet impingement)

  • 서정수;김한곤
    • 에너지공학
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    • 제23권3호
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    • pp.21-26
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    • 2014
  • 유럽 원전 시장 개척을 위해 개발 중인 EU-APR1400은 중대사고 대처설비로 노외 노심용융물 보유 및 냉각을 위한 소위 Core catcher라 불리는 노외 노심용융물 냉각설비를 개발 중이며, Core catcher body를 노심용융물로부터 보호하기 위하여 노심용융물의 물성 및 상태를 변화시켜 냉각 및 보유에 유리하게 하는 희생물질을 설치한다. 중대사고 시 원자로 압력용기의 틈으로부터 노심용융물이 분출되어 희생물질에 충돌 시 열 전달량이 매우 증가하게 되므로, 이 때 노심용융물 제트의 충돌에 의한 희생물질의 침식율을 정확하게 예측하는 것은 매우 중요하다. 이 논문에서는 경계층 이론을 기반으로 한 희생물질 침식 모형을 제안하고 KAERI에서 수행한 실험결과와 비교하였다.

희생층을 이용한 은 나노와이어 패터닝 공정 개발 (Development of Ag Nanowire Patterning Process Using Sacrificial Layer)

  • 하본희;조성진
    • 한국전기전자재료학회논문지
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    • 제29권7호
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    • pp.435-439
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    • 2016
  • We developed a Ag nanowire patterning technique using a water-soluble sacrificial layer. To form a water-soluble sacrificial layer, germanium was deposited on the substrate and then water-soluble germanium oxide was simply formed by thermal oxidation of germanium using a conventional furnace. The formation of Ag nanowire patterns with various line and space arrangements was successfully demonstrated using this patterning process. The main advantage of this patterning technique is that it does not use a strong acid etchant, thereby preventing damage to the Ag nanowire during the patterning process.

CORROSION BEHAVIOR OF Al-Zn ALLOY AS A SACRIFICIAL ANODE OF ORV TUBES

  • Jin, Huh;Lee, Ho-Kyun;Lee, Jae-Ho
    • 한국표면공학회지
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    • 제32권3호
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    • pp.452-455
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    • 1999
  • ORV which vaporizes LNG to NG is consisted of tube and header whose substrate is aluminum alloy. The corrosion of the tube is very severe because of sea water being used as the heating source. In this research to protect ORV substrate material, the corrosion behavior of aluminum alloys was investigated for the sacrificial role of Al-Zn alloy for ORV tubes. The electrochemical behavior of aluminum alloys in sea water was investigated. The corrosion behavior of thermally-sprayed and cladded samples were compared through salt spray tests. Al-Zn alloy can act as a sacrificial anode and cladded Al-Zn alloy has a better corrosion resistance than that of thermally sprayed one. The galvanic effect of Al-Zn to substrate material was conformed from scratched sample tests.

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An analytical study on the Youngjeob Dogam Sajechong Euigwae of Choson Dynasty(1609 year)

  • 김상보;이성우
    • 동아시아식생활학회지
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    • 제2권2호
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    • pp.201-220
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    • 1992
  • To analyze royal nad Chinese envoy procession, and sacrificial rite of Chinese envoy for Choson Dynasty, the author studied historic book-Youngjeob Dogam Sajechong Euigwae of Choson Dynasty(1609 year) in which Chinese envoy procession for sacrificial rite in Choson Dynasty were described. The results obtained from this study were as follows. 1. Sacrificial rite of Chinese envoy for Choson Dynasty were Yellow paper burning and performing a sacrificial rite of chinese envoy. 2. Order of Chinese envoy procession for Yellow paper burng and performint a sacrificial rite of Chinese envoy, was civil and military officers, flag procession, drum, palanquin of incense, palanquin of guneral oration, palaquin of material for guneral expenses, palanquin of rich viands and sumptuous fare and Chinese envoy. 3. Things offered in sacrifice of Yellow paper burning were fried cake made of wheat flour, honey and oil, fried gutinous rice cake, patterned savory cake, fruits, meat fish and others broil, slices of boiled beef, soup, stew, noodles, 3cups of alcohol, rice cake and water. 4. Things offered in sacrifice of performing a sacrificial rite of Chinese envoy were a cattle, a hog, a sheep, 3 cups of alcohol and etc.

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MEMS switch 응용을 위한 free standing 금속 구조물에 관한 연구 (A free standing metal structures for MEMS switches)

  • 황현석;김응권;강현일;이규일;이태용;송준태
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2005년도 추계학술대회 논문집 Vol.18
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    • pp.187-188
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    • 2005
  • In this paper, big free standing metal structures for electrostatic MEMS switches are easily fabricated using photoresist sacrificial layer. The entire process sequence, through the removal of the sacrificial layer, is kept below 150 $^{\circ}C$ to avoid curing problem of photoresist sacrificial layer. Metal structure is fabricated by thermal evaporator and a self test electrode is fabricated underlying metal suspended structure for testing by electrostatic force. The new wet release process is considered using methanol rinse, general wet release process cause stiction problem by capillary force during drying, and the yield is dramatically improved than previous wet release process using DI water rinse. The fabrication becomes much simpler and cheaper with use of a photoresist sacrificial layer.

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희생양극을 이용한 태양광 리본의 부식 저감 (Corrosion mitigation of photovoltaic ribbon using a sacrificial anode)

  • 오원욱;천성일
    • 한국산학기술학회논문지
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    • 제18권3호
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    • pp.681-686
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    • 2017
  • 태양광 모듈에서 태양전지를 연결해주는 인터커넥터로 리본 솔더로 SnPbAg가 사용되고, 옥외 태양광 발전에 장기간 노출시 리본의 부식으로 인한 열화가 흔히 관찰된다. 이러한 부식현상으로 인하여 리본과 태양전지의 접합이 약해져 접촉저항이 증가하고, 또한 리본 자체의 직렬 저항이 증가하게 되어 태양전지의 전압 전류 곡선에서 충진률 손실로 출력이 저하된다. 본 논문에서는 리본의 부식을 완화시킬 수 있는 방법으로 희생양극법을 이용하여 순수 알루미늄 및 아연, 알루미늄, 아연 그리고 마그네슘의 합금을 이용한 5가지 희생양극 소재의 부식에 의한 열화 저감을 연구하였다. 전기화학적 방법으로 희생양극 소재의 개방회로 전위와 폐쇄회로 전위를 측정하였고, 포텐시오다이나믹 분극 곡선을 측정하고, 영저항전류계를 이용하여 리본과 소재간의 갈바닉 전류를 측정하였다. 또한, 아세트산과, NaCl에 리본과 희생양극 소재의 부착 전후의 침지시험과 4셀 미니모듈로 제작한 후 1500시간 고온고습 시험 전후 출력을 평가하였다. 그 결과 Al-3Mg와 Al-3Zn-1Mg의 희생양극 소재가 부식속도가 느리고, 출력저하를 저감시킬 뿐만 아니라 장기 안정성에도 효과적인 것으로 평가된다.

Corium melt researches at VESTA test facility

  • Kim, Hwan Yeol;An, Sang Mo;Jung, Jaehoon;Ha, Kwang Soon;Song, Jin Ho
    • Nuclear Engineering and Technology
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    • 제49권7호
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    • pp.1547-1554
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    • 2017
  • VESTA (Verification of Ex-vessel corium STAbilization) and VESTA-S (-small) test facilities were constructed at the Korea Atomic Energy Research Institute in 2010 to perform various corium melt experiments. Since then, several tests have been performed for the verification of an ex-vessel core catcher design for the EU-APR1400. Ablation tests of an impinging $ZrO_2$ melt jet on a sacrificial material were performed to investigate the ablation characteristics. $ZrO_2$ melt in an amount of 65-70 kg was discharged onto a sacrificial material through a well-designed nozzle, after which the ablation depths were measured. Interaction tests between the metallic melt and sacrificial material were performed to investigate the interaction kinetics of the sacrificial material. Two types of melt were used: one is a metallic corium melt with Fe 46%, U 31%, Zr 16%, and Cr 7% (maximum possible content of U and Zr for C-40), and the other is a stainless steel (SUS304) melt. Metallic melt in an amount of 1.5-2.0 kg was delivered onto the sacrificial material, and the ablation depths were measured. Penetration tube failure tests were performed for an APR1400 equipped with 61 in-core instrumentation penetration nozzles and extended tubes at the reactor lower vessel. $ZrO_2$ melt was generated in a melting crucible and delivered down into an interaction crucible where the test specimen is installed. To evaluate the tube ejection mechanism, temperature distributions of the reactor bottom head and in-core instrumentation penetration were measured by a series of thermocouples embedded along the specimen. In addition, lower vessel failure tests for the Fukushima Daiichi nuclear power plant are being performed. As a first step, the configuration of the molten core in the plant was investigated by a melting and solidification experiment. Approximately 5 kg of a mixture, whose composition in terms of weight is $UO_2$ 60%, Zr 10%, $ZrO_2$ 15%, SUS304 14%, and $B_4C$ 1%, was melted in a cold crucible using an induction heating technique.

플라즈마 에칭으로 손상된 4H-실리콘 카바이드 기판위에 제작된 MOS 커패시터의 전기적 특성 (Electrical Characterization of MOS (metal-oxide-semiconductor) Capacitors on Plasma Etch-damaged 4H-Silicon Carbide)

  • 조남규;구상모;우용득;이상권
    • 한국전기전자재료학회논문지
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    • 제17권4호
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    • pp.373-377
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    • 2004
  • We have investigated the electrical characterization of metal-oxide-semiconductor (MOS) capacitors formed on the inductively coupled plasma (ICP) etch-damaged both n- and p-type 4H-SiC. We found that there was an effect of a sacrificial oxidation treatment on the etch-damaged surfaces. Current-voltage and capacitance-voltage measurements of these MOS capacitors were used and referenced to those of prepared control samples without etch damage. It has been found that a sacrificial oxidation treatment can improve the electrical characteristics of MOS capacitors on etch-damaged 4H-SiC since the effective interface density and fixed oxide charges of etch-damaged samples have been found to increase while the breakdown field strength of the oxide decreased and the barrier height at the SiC-SiO$_2$ interface decreased for MOS capacitors on etch-damaged surfaces.

SOG 희생층을 이용한 마이크로 구조의 형성 (Fabrication of Micro-structure using SOG as a Sacrificial Layer)

  • 신경식;이성준;김정구;최연화;김철주
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1996년도 하계학술대회 논문집 C
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    • pp.2001-2003
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    • 1996
  • In this study, Allied Signal 211 SOG was used as a sacrificial material. After researching its etching properties, we adapted it to bottom-drive micrometers. SOG was superior etch rate and roughness to them of PSG or CVD-oxide and possible to low-temperature processing. Etching properties of SOG depended on the temperature and duration of its bake and cure. SOG used in the fabrication of bottom-drive micrometers showed us usefulness as a sacrificial layer and haying a least influence on machines on it in comparison with conventional sacrificial materials.

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마이크로머시닝을 위한 새로운 희생층인 다결정-산화막의 특성 (Characteristics of Poly-Oxide of New Sacrificial Layer for Micromachining)

  • 홍순관;김철주
    • 센서학회지
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    • 제5권1호
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    • pp.71-77
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    • 1996
  • 마이크로머시닝의 구조재료인 다결정 Si이 희생산화막의 영향을 받음을 고려하여 다결정 Si을 열산화시킨 다결정-산화막을 새로운 희생산화막의 재료로서 제안하고 평가하였다. 다결정-산화막상에 성장시킨 다결정 Si은 통상의 희생산화막상에 성장시키는 경우보다 grain size가 증가하였고, XRD결과를 통해 (111) texture의 증가와, 부가적인 (220) texture가 형성됨을 관찰하였다. 또한, 다결정-산화막상에 성장시킨 다결정 Si의 경우, 그 응력이 작고 균일한 분포를 나타내었다.

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