• EDISON SW 활용 경진대회 논문집
• /
• 제5회(2016년)
• /
• pp.373-376
• /
• 2016

Transition metal dichalcogenides (TMDs) such as $MoS_2$ is the thinnest semiconductor, exhibits promising prospects in the applications of optoelectronics, catalysis and hydrogen storage devices. Uniform and high quality $MoS_2$ is highly desirable in large area for its applications on commercial scale and fundamental research. Many experimental techniques i.e CVD have been developed to successfully synthesis $MoS_2$ on large scale, here in this work atomistic detail to understand the growth mechanism is addressed which was greatly overlooked. Here based on first principles calculation we found that polarity of seeding promter (crystal violet considerd in this work) controls the growth mechanism. It is also found that molybdenum destroys the precursor while sulfur adsorption with precursor is favorable.

• Restorative Dentistry and Endodontics
• /
• 제4권1호
• /
• pp.29-34
• /
• 1978

The purpose of this study was to measure penetration of dye stuff(5% Methylene blue, Hematoxylin, Crystal violet and Safranin-O) on silicate cement, Adaptic, Hi-pol and unfilled resin. Each filling material was mixed on the mixing pad and the mixed material was inserted with condensation force of 500gr, 1000gr and 2000gr and without condensation force into preformed glass tube (10mm in diameter and 10mm in height). The specimen was stored in the air for 24 hours, then specimen was immersed in various dye solution (5% methylene blue, hematoxin, crystal violet and safranin-O) for different period of time (l hour and 24 hours). These dye-treated specimen was cut horizontally at the middle portion and the dye penetration in cut surface was measured. Following results were obtained. 1. Pentration of various dye was excessive in silicate cement with and without Condensation force. 2. There has been no evidence of dye penetration in unfilled resin. 3. Dye penetration occurced with in 1 hour period and the extending time didn't affect the dye penetration.

• 한국결정성장학회지
• /
• 제30권5호
• /
• pp.163-167
• /
• 2020

본 연구에서는 PVT(Physical Vapor Transport) 방법을 이용하여 반도체 식각 공정용 소재로 사용되는 링 모양의 SiC(Silicon carbide) 다결정을 제조하였다. 흑연 도가니 내부에 원기둥 모양의 흑연 구조물을 배치하여 PVT법에 의한 링 모양의 SiC 다결정을 성장시켰다. 성장된 결정은 Raman 및 UVF(Ultra Violet Fluorescence) 분석을 이용하여 결정의 상분석을 하였고, SEM(Scanning Electron Microscope), EDS(Energy Dispersive Spectroscopy) 분석을 통해 미세조직 및 성분을 확인하였다. PVT 성장 초기의 온도변화를 통하여 SiC 다결정의 결정립 크기와 성장 속도를 조절할 수 있었다.

• 생명과학회지
• /
• 제18권10호
• /
• pp.1331-1335
• /
• 2008

여러 가지 난분해성 색소에 대하여 탈색능을 나타내는 Klebsiella pneumoniae WL-5이 염색폐수처리장의 활성슬러지로부터 분리되었다. 이 세균은 정치배양과 at pH 6-8 및 $30-35^{\circ}C$에서 높은 탈색능을 나타내었다. Congo Red색소에 대해서는 $200\;{\mu}M$ 농도에서 12시간 배양하였을 때 90% 이상이 탈색되었고, Malachite Green, Brilliant Green, Reactive Black-5에 대해서는 $10\;{\mu}M$ 농도에서 80% 이상이 탈색되었지만, Reactive Red-120, Reactive Orange-16, Crystal Violet에 대해서는 $10\;{\mu}M$ 농도에서 각각 46%, 25%, 13%의 비교적 낮은 탈색능을 나타내었다. 트리페닐메탄계 색소는 세포표면에의 흡착에 의한 탈색을 나타내었고, 아조계 색소는 지금까지 알려져 있지 않는 새로운 효소반응계에 의해서 탈색된다는 것을 제시하였다.

• 한국결정성장학회지
• /
• 제16권6호
• /
• pp.267-272
• /
• 2006

일련의 $Sr_{1-x}Ca_xGa_2S_4:Ce,Na$ 형광체를 고상법으로 합성하였다. $Sr_{1-x}Ca_xGa_2S_4:Ce,Na$의 구조와 발광 특성을 조사하였다. $Sr_{1-x}Ca_xGa_2S_4:Ce,Na$은 보라색 발광 다이오드의 발광 파장인 400 nm에서 강한 흡수가 있다. $SrGa_2S_4:Ce,Na$의 발광 봉우리는 448 nm와 485 nm에 있다. $Sr_{1-x}Ca_xGa_2S_4:Ce,Na$에서 Sr이 Ca으로 부분 치환되면 발광 파장이 장파장으로 이동된다. 다파장 백색 LED를 제작할 때 $Sr_{1-x}Ca_xGa_2S_4:Ce,Na$은 보라색 LED로 여기하여 청색 발광 형광체로 사용 될 수 있다.

• 한국결정성장학회지
• /
• 제24권5호
• /
• pp.183-189
• /
• 2014

본 연구에서는 도예가들이 경험적으로 제조하여 사용하는 diopside 결정유약에 $Co_3O_4$와 $Fe_2O_3$를 첨가하였을 경우 Co와 Fe이 유약과 diopside 결정의 발색에 미치는 영향을 연구하고자 하였다. 그 결과 diopside 결정유약에 $Co_3O_4$를 넣을 경우 유약의 색상은 blue색을 띠며 결정의 색상은 diopside 결정에 Co가 고용되면서 pastel violet색을 띠었으며 diopside 결정유약에 $Fe_2O_3$를 넣을 경우 유약의 색상은 brown색을, 결정의 색상은 diopside 결정에 Fe가 고용되면서 goldenrod색을 띠었다. 그리고 diopside 결정유약 표면에 석출된 결정은 diopside 결정과 diopside precursor로 이루어져 있었다. 또한 유지시간이 길어짐에 따라 diopside precursor의 량은 줄고 diopside 결정량은 많아졌다. Diopside 결정에는 Fe보다는 Co가 더 잘 고용되었으며, Co가 고용될 경우 diopside 결정성은 더 좋아져 특성 peak의 강도가 높아졌다. 그리고 Fe이 고용되면 특성 peak의 강도는 낮아지면서 diopside 결정은 부분적으로 와해됨을 알 수 있었다.

• Bulletin of the Korean Chemical Society
• /
• 제34권1호
• /
• pp.128-132
• /
• 2013

L-Arginine semi-oxalate (LASO) single crystal has been grown by solution growth technique at room temperature. The crystal structure and lattice parameters were determined for the grown crystal by single crystal X-ray diffraction studies. Photoluminescence studies confirm the violet fluorescence emission peak at 395 nm. Optical constants like band gap, refractive index, reflectance, extinction coefficient and electric susceptibility were determined from UV-VIS-NIR spectrum. The dielectric constant, dielectric loss and ac conductivity of the compound were calculated at different temperatures and frequencies to analyze the electrical properties. The solid state parameters such as plasma energy, Penn gap, Fermi energy and polarizability were calculated to analyze second harmonic generation (SHG). Nonlinear optical property was discussed to confirm the SHG efficiency of the grown crystal.

• 한국결정성장학회:학술대회논문집
• /
• 한국결정성장학회 1998년도 PROCEEDINGS OF THE 14TH KACG TECHNICAL MEETING AND THE 5TH KOREA-JAPAN EMGS (ELECTRONIC MATERIALS GROWTH SYMPOSIUM)
• /
• pp.165-167
• /
• 1998

Nd:YAG crystals were grown by Horizontal Bridgman method. The effects of sliding rate (growth rate) of Molydbenum container, growth atmosphere and concentration of Neodymium ions on crystal qualities were investigated. The size of the crystals grown was up to 150-200 mm in length, 70 mm in width and 25-35 mm in thickness. Crystals grown under the optimum conditions were violet, transparent and could not be observed any macroscopic defects. Under the polarizing microscopoc observations with crossed polar, striations, {211} facets and inclusions were detected. With the grown crystals, prototypes of laser rods for 1.06$\mu$m laser application were manufactured and then characterized. As a result, we can get high quality of Nd:YAG laser rods with <111> and <110> axis, 63 mm in length and6.3 mm in diameter.

• 한국결정성장학회지
• /
• 제17권3호
• /
• pp.108-112
• /
• 2007

광원에 따라 색상이 변화하는 cubic zirconia 단결정을 skull melting 법으로 성장하였다. Co와 Nd에 의해서 황색 영역의 강한 흡수가 일어나며, Fe에 의해 보라색 영역의 흡수가 일어남에 따라 광원이 형광등에서 백열등으로 변화할 때 청-녹색에서 적-자색으로 변화가 발생한다. 첨가물에 의해서 뿐만 아니라 yttria 함량과 열처리 조건 변화에 의해서도 결정의 색이 변화하였다.

• 한국미생물·생명공학회지
• /
• 제25권6호
• /
• pp.630-635
• /
• 1997

Decolorization of congo red, methyl orange, poly R478, remazol brilliant blue R and crystal violet by white-rot fungus Trametes sp. CJ-105, isolated in Korea, was investigated. Remazol blue and methyl orange were almost completely decolorized after 2 days of culture, but congo red, crystal violet and poly R478 were decolorized by about 80%, 40% and 30% after 10 days of culture, respectively. As a result of determination of cell mass and enzyme activity, it was shown that color removal efficiency was related to cell mass and enzyme activity, and also found that only laccase (E.C.1.10.3.2) activity was existed in the culture broth. The decolorization ratios of remazol blue in the concentrations of 100ppm to 3, 000 ppm were 85% and above after 2 days of culture. In this study, we found that white-rot fungus, Trametes sp. CJ-105, was effective in decolorizing a wide range of structurally different synthetic dyes.