• 대한화학회지
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• 제41권10호
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• pp.535-540
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• 1997

탄산칼륨 존재하에서 사염화규소는 1차, 2차, 3차 및 벤질알코올 유도체 뿐 만 아니라 시클로헥산올과 같은 고리형 알코올, 알릴 알코올등의 염소화반응에 효과적임을 알 수 있었다. 탄산칼륨이 사염화규소의 반응성이 큰 규소-염소 결합과 반응하여 생성될 수 있는 불안정한 중간체인 Trichlorosilyloxy carbonylchloride 혹은 최종적으로 평형농도 만큼 소량씩 생성되리라 예상되는 Phosgene은 모두 반응메카니즘적으로 알코올의 염소화반응에 관여할 수 있음을 알았다.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1997년도 고액공존금속의 성형기술 심포지엄
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• pp.160-173
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• 1997

Microstructure of hypereutectic Al-17wt.% Si alloy, fabricated by mechanical stirring and by reheating at semi-solid state, was investigated by optical microscope. Flow behavior semi-solid metal also was investigated at diffentent mould temperatures 280$^{\circ}C$, 290$^{\circ}C$ and 300$^{\circ}C$. Size of silicon particles were increased over 100$\mu\textrm{m}$ during solidification as a result of stirring. It is considered as microstructural coarsening by bonding between neighbouring primary silion particles during stirring of slurry. In case of reheating at semi-solid state, however, primary silicon particle was not increased at size of 40$\mu\textrm{m}$ and nearly spherical aluminum solde particle also could be obtained uniformly in distribution. The fludity of Al-17wt.% Si alloys at semi-solid state was improved when solid fraction was 0.7 at mould temperature of 300$^{\circ}C$ than other conditions.

• 한국주조공학회지
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• 제6권2호
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• pp.116-121
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• 1986

The effects of pressure during solidification on macro-and micro-structures have been studied in pure aluminium and Al-Si alloys. The application of pressure during solidifcation accelerated both equiaxed and columnar dendritic-growth due to stimulating of equiaxed survival and faster preferential growth of primary dendrites against the parallel direction of heat flow. Burden-Hunt model was modified to express the significant changes of CET behaviours under pressure. A further point to be noted was that greatly fine eutectic silicon flakes ($0.5\;{\times}\;13{\mu}m$) with the decrease of halo layers ($7{\mu}m$) of aluminium riched phases in the periphery of primary silicon particles were observed when pressure was applied during solidification.

• 한국재료학회지
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• 제15권7호
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• pp.480-485
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• 2005

Sc has been known to be an very effective ppt-hardening element in Al and Al alloys and also to be effective in modification of eutectic Si in hypoeutectic Al-Si alloys. The modification mechanism of Sc is different from that of the traditional modifier Sr in Al-Si alloys. In the present study the effects of Sc on the primary and eutectic Si in hypereutectic Al-Si alloys were investigated with evaluating the microstructures with OM, EPMA and EBSD methods. The results represent that Sc has only a small effect on primary Si when added less than $0.8wt\%$. However, when Sc addition leading to the precipitation of metallic Sc within primary Si reaches $1.6wt\%$, very coarse primary Si occurs.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2011년도 전력전자학술대회
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• pp.346-347
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• 2011

본 논문에서는 정전류 LED조명 구동을 위한 일차측 전류 제어의 새로운 기법을 제안한다. 일정한 온-타임으로 동작하는 경계 모드(Critical Mode) 플라이백 타입으로 우수한 역률을 달성하였고, 의사 공진(Quasi-resonant) 동작으로 스위칭 손실을 최소화 하였다. 본문에서 LED전류가 5% 이하로 정전류 제어되는 9W급 플라이백 타입의 일차 측 전류 제어 기법을 실험으로 검증한다.

• 한국전기전자재료학회논문지
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• 제17권12호
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• pp.1352-1355
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• 2004

We have applied front contact metallization of plated nickel and copper for high efficiency passivated emitter rear contact(PERC) solar cell. Ni is shown to be a suitable barrier to Cu diffusion as well as desirable contact metal to silicon. The plating technique is a preferred method for commercial solar cell fabrication because it is a room temperature process with high growth rates and good morphology. In this system, the electroless plated Ni is utilized as the contact to silicon and the plated Cu serves as the primary conductor layer instead of traditional solution that are based on Ti/Pd/Ag contact system. Experimental results are shown for over 20 % PERC cells with the Plated Ni/Cu contact system for good performance at low cost.

• 한국주조공학회지
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• 제26권6호
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• pp.241-248
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• 2006

The effects of silicon content and melt treatment on the fluidity of Al-Si alloys during squeeze casting were investigated. The fluidity of Al-3.0 wt%Si alloy was found to be lower than that of Al-1.0 wt%Si and the fluidity of the alloy with more than 3.0 wt%Si increased with the silicon content upto 13.0 wt% and rather decreased with15.0 wt%. The fluidity was also increased by the separated treatment of grain refinement or eutectic modification, and even more by the simultaneous treatment of both. The fluidity of hypereutectic alloy was increased by the refinement of primary silicon particle.

• 한국위성정보통신학회논문지
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• 제10권4호
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• pp.6-11
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• 2015

PPS 소자가 삽입된 N형 실리콘 제어 정류기(NSCR_PPS)소자에서 게이트와 $N^+$ 확산층 간격(Gate to Primary $N^+$ diffusion Space; GPNS)의 변화가 정전기 보호 성능에 미치는 영향을 연구하였다. FPW 구조와 CPS 이온주입을 행하지 않은 구조를 갖는 종래의 NSCR 표준소자는 on 저항, 스냅백 홀딩 전압 및 열적 브레이크다운 전압이 너무 낮아 정전기 보호소자의 필요조건을 만족시키지 못해 마이크로칩의 정전기보호소자로 적용이 어려웠다. 그러나 본 연구에서 제안하는 PPW 구조와 CPS 이온주입을 동시에 적용하여 변형설계된 소자에서는 GPNS의 변화가 정전기 보호성능의 향상에 영향을 주는 중요한 파라미터였으며, 정전기보호소자의 설계창을 만족시키는 향상된 정전기보호성능을 나타내어 고전압 동작용 마이크로 칩의 정전기보호 소자로 적용 가능함을 확인하였다.

• 대한화학회지
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• 제41권10호
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• pp.541-546
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• 1997

이산화망간 존재하에서 사염화규소는 1차, 2차, 3차 및 벤질알코올 유도체 뿐 만 아니라 시클로헥산올과 같은 고리형 알코올, 알릴 알코올 등의 염소화반응을 정량적으로 수행할 수 있음을 발견하였다. 먼저 이산화망간이 사염화규소의 반응성이 큰 규소-염소 결합에 삽입되어 불안정한 중간체인 Manganese(IV) oxodichloride를 생성하고 이 중간체는 계속하여 사염화규소와 반응하여 최종적으로 사염화망간을 생성하리라 예상된다. 이렇게 생성되리라 예상되는 화학종들은 모두 반응메카니즘적으로 알코올의 염소화반응에 관여할 수 있음을 알았다. 이 반응은 Thionyl chloride나 삼염화인등을 사용한 고전적인 알코올의 염소화반응에 비하여 많은 장점을 가짐을 알 수 있었다.

• Current Photovoltaic Research
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• 제12권1호
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• pp.6-16
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• 2024

The efficiency of silicon solar cells is approaching a theoretical limit referred to as 'the state of the art'. Consequently, maintaining efficiency is more productive than pursuing improvements the last room for limiting efficiency. One of the primary considerations in silicon module conservation is the occurrence of failures and degradation. Degradation can be mitigated during the cell manufacturing stage, unlike physical and spontaneous failure. It is mostly because the chemical reaction is triggered by the carrier generation of thermal and light injection, an inherent aspect of the solar cell environment. Therefore, numerous researchers and cell manufacturers are engaged in implementing mitigation strategies based on the physical degradation mechanism.