친환경적인 전기자동차, 전기 추진 선박, 하이브리드 자동차, 전철 등의 구성 요소 중 기존 파워 디바이스에서 사용 중인 실리 콘(Si)을 실리콘 카바이드(SiC, silicon carbide)로 대체하려는 연구가 진행 중이다. 고품질의 SiC 결정 성장을 시키기 위해 다양한 방법 중 상 부 종자 용액 성장(top seeded solution growth, TSSG)법이 큰 주목을 받고 있다. 그러나 SiC 결정 성장 시, 느린 성장 속도뿐만 아니라 많은 결함을 갖는 문제를 갖고 있다. 그래서 본 연구에서는 SiC 단결정을 성장 시키는 TSSG법의 개선을 위한 기초 연구를 진행하였다. 기존에 많이 사용되는 Si, Si0.6Cr0.4 용융 물질와 탄소 도가니와 관계를 가열 온도에 따른 접촉각과 자연 냉각 후 시료의 단면의 차이점을 통해 비 교 분석하였다. 젖음성 분석 시험 장비를 이용하여 탄소 도가니로 쓰이는 카본판 위에 Si과 Si0.6Cr0.4를 놓고 가열 및 용융 시키며 접촉각의 변화를 측정하였고, 가열 종료 후 자연 냉각된 시료의 단면을 관찰하였다. 결과적으로 1800 ℃에서 Si, Si0.6Cr0.4와 탄소판 간의 접촉각이 10°정도 차이를 나타냈다. 단면 관찰에서는 Si의 경우, 탄소판 안으로 스며든 후 굳은 모습을 확인할 수 있었다. 반면, Si0.6Cr0.4의 경우는 탄 소판 안으로 스며든 범위가 훨씬 더 적게 나타냈다. 본 연구의 결과는 TSSG법을 활용한 SiC 단결정 성장을 위한 연구의 기초 자료로 활용 될 것으로 기대된다.

Spherical monosized pure aluminum (Al) particles are successfully fabricated by the pulsated orifice ejection method (POEM). The surface reaction between Al and the graphite crucible is investigated by analysing the microstructure and chemical composition of the materials. No significant chemical reaction occurs between Al and the graphite owing to the crystalline Al oxide (γ-Al2O3) layer generated in the initial state. The γ-Al2O3 layer is clearly observed in all regions between the Al particles and graphite via transmission electron microscopy and confirmed by the selected area diffraction pattern. The morphology of the γ-Al2O3 layer perfectly follows the surface morphology of the graphite crucible, which showed nanoscale roughness. This implies that molten Al could not directly contact graphite even though the surface of the crucible became rough to some extent. However, this passivation phenomenon allowed the successful fabrication of monosized pure Al particles. Therefore, POEM is a useful process at least to manufacture monosized pure Al particles.

This study aims to re-read aspects of violence reproduced in The Crucible through the theories of violence of Walter Benjamin, Slavoj Žižek and Hannah Arendt. This study intends to re-read The Crucible through the theories of violence of Benjamin, Žižek and Arendt because of what they commonly emphasized, that is, the fact that escape from stereotype image of violence provides significant implications for contemplation on violence. When we re-read The Crucible by taking one step back from the power of accusation wrapped in fury and lunacy and taking notice on stark law-making and law-preserving nature of Salem society, foundation can be created to contemplate and reflect on its ‘systemic violence.’ In addition, Arendt’s theory of violence which saw opposing relationship between ‘violence’ and ‘power’ and between ‘behavior’ and ‘action’ provides insight into the origin of witch hunt in Salem society and into understanding the meaning of John Proctor’s resistance.

In KAERI’s previous phosphate precipitation tests, the dispersed powder of lithium phosphate (Li3PO4) as a precipitation agent reacted with various metal chlorides in a simulated LiCl-KCl molten salt. The reaction of metal chlorides composed of actinides such as uranium and three rare earths (Nd, Ce and La) with lithium phosphate is a solid-liquid reaction. A phosphorylation reaction rate is very fast and the metal phosphates as a reaction product precipitated on the bottom of the molten salt crucible. One of the recovery methods of the metal phosphate precipitates is segregation the lower part (precipitates) of the salt ingot using the various cutting tools. Recently, a new phosphorylation experiment using lithium phosphate ingots carried out in order to collect the metal phosphate precipitates into a small recovering vessel, and the test result of this new method was feasible. However, the reaction rate of test using lithium phosphate ingot is extremely slower than that of test using lithium phosphate powder. In this study, the precipitation reactor design (a tapered crucible with polished inner surface) used for phosphorylation reaction showed that the salt ingot with metal phosphate precipitates could be detached from a tapered stainless steel crucible. We propose that the recovery of precipitates from a salt ingot is possible by introducing a dividing plate structure into a molten salt and by positioning it at the interface between salt and precipitated metal phosphate.