• 한국결정성장학회지
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• 제13권5호
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• pp.205-210
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• 2003

스컬법에 의해 alexandrite-like cubic zirconia 단결정을 성장 시켰다. 스컬용융시 R.F generator는 35 ㎾, 2 MHz 였다. 단결정들은 전이금속이온인 Pr을 1 또는 1.5 wt%와 Nd를 0.5 또는 l wt%를 함께 첨가하여 성장시켰으며, 성장 후0.25 mm의 slice와 12 mm의 round brilliant cut으로 연마하였다. 연마석은 공기중 또는 질소분위기에서 $1000^{\circ}C$에서 2시간 열처리하였으며 optical absorption spectra($\lambda$ = 400∼700 nm)를 얻었다.

• 한국안전학회지
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• 제14권4호
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• pp.114-119
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• 1999

When NaOCl was generated and put into sea-water cooling machine in order to overcome the biological hindrances against sea-water cooling machine, it was converted into metallic ion, particularly Ca and Mg, as a hydrate in sea-water and is to stick to electrolyte as a side reaction. This phenomena make the distance between the electrolytes narrow to decrease the flow rate, which induces the local vortex flow which erodes the pole plate. Moreover, this increases the resistance of the electrolyte as well as voltage to decrease the electrolytic efficiency, which has curtailed a chlorine yield and caused a pole plate cut. We are able to overcome these problems by chemical cleaning and intend to extend the life-time of electrolyte and to increase output of the sea-water electrolysis facilities by studying optimal policy regarding chemical cleaning of electrolytic cell. Cleaning time of electrolytic facilities is determined when both increase in electrolytic efficiency and decrease in pole-plate voltage are 10%. At this time as operating current of electrolytic facilities is high, operating time is diminished. Whereas, parameter of end point determination according to cleaning is Mg ionic concentration in solution. When we use Cleaner as a 7wt% HCl, cleaning time is about 80min proper. We are able to maintain pole plate performance by protecting against pole plate cut by means of electrolytic by-product, improve operating rate of facilities, and cut down on maintenance expenditure after acidic cleaning.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2009년도 추계학술대회 논문집
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• pp.49-49
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• 2009

카메라 모듈용 적외선 차단 필터를 설계하고 이온빔 증착 장비를 이용한 코팅 공정 후 특성을 조사하였다. 코팅 실험에 앞서 Macleod 프로그램을 이용하여 640nm 차단 필터를 설계하였으며, 실험은 Ion-Assisted Deposition 장비를 사용하여 $TiO_2/SiO_2$ 유전층을 다층 박막으로 증착하였다. 투과도 분석에서 640nm 차단 필터는 설계 곡선과 약 8nm 이내에서 일치하였으며, 갓 성장된 박막 투과도는 400~600nm에서 약 80% 이었으며, 급속열처리 및 열처리 후 약 5% 증가된 투과도를 보였다. 표면거칠기 또한 감소하였다. 따라서 열처리로 인한 재결정화 및 결함감소에 의해 필터특성이 향상되었음을 알 수 있었다.

• 대한기계학회논문집A
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• 제24권4호
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• pp.900-906
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• 2000

Ceramic, PCD and CBN tools are available for the difficult-to-cut-materials such as hardened carbon tool steel, stainless steel, Inconel 718 and etc. Ceramic tools are likely to be chipped and abruptly broken before the appearance of normal wear in turning. Ceramic tools are suitable for continuous in turning, not for intermittent in milling. In this study, TiN/TiCN multi-layer coated ceramic tools were found to restrain the chipping, breaking and early fracture and to increase the critical cutting speed owing to TiN/TiCN multi-layer coating in Arc Ion Plating of PVD method.

• 한국생산제조학회지
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• 제9권2호
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• pp.87-95
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• 2000

By using AIP(Arc Ion Plating) of a physical vapor deposition for the first time in Korea a ceramic tool whose surface is coated single layeredly with TiN is developed. In addition cutting resistance appearing in the process of finishing cut of hardened carbon tool steel STC3 is studied. The principal and radial components of cutting resistance in those cutting conditions appear to be the same or similar and the feed component is relatively small. The feed component is found to be in proportion to cutting width and the radial component in proportion to cutting thickness. Owing to coating the cutting resistance of a TiN coated ceramic tool increas-es compared with that of a general ceramic tool.

• 한국생산제조학회지
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• 제9권1호
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• pp.96-101
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• 2000

Ceramic, PCD and CBN tools are available for the difficult-to-cut-materials such as hardened carbon tool steel, stainless steel, Inconel 718 and etc.. Ceramic toolsare likely to be chipped and abruptly broken before the appearance of normal wear in turning. Ther2efore ceramic tools are suitable for continuous cut in turning not for intermittent in milling. In this study, TiN/TiCN multi-layer coated ceramic tools were found to restrain the chipping, breaking and early fracture and to increase the critical cutting speed owing to TiN/TiCN multi-layer coating in Arc Ion Plating of PVD method.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2010년도 하계학술대회 논문집
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• pp.169-169
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• 2010

650nm 적외선 차단 필터를 Macleod 프로그램을 이용하여 설계하고, 이온보조증착(IAD) 장비를 이용하여 코팅한 후 투과도, 파장, 두께특성을 조사하였다. 차단필터의 증착물질은 $TiO_2$ (n=2.30) /$SiO_2$ (n=1.46) 을 사용하여 45층의 다층 박막으로 증착하였다. 코팅된 차단필터는 차단파장이 651 nm로써 평균 ${\pm}5$ nm 이내의 편차를 보였다. 420~630 nm 파장영역에서 평균 투과도는 89%이었으며, 투과도의 균일도는 약 2.12로써 매우 균일하였다. 투과도기 단파장 영역에서 감소된 것은 다층박막 증착 시 산소가 결핍된 것으로 판단된다.

• 전기화학회지
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• 제19권3호
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• pp.114-121
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• 2016

본 연구에서는 리튬이온전지의 충방전시 발생하는 발열특성을 CFD 모델링하고, 발열에 따른 충방전 특성을 해석하였다. 리튬이온전지는 직교 파우치형 구조로서 두께방향으로의 1차원계로 설정하여, 전류밀도 방정식, 열 및 물질전달 지배방정식을 도입하였다. Cut-off 전압이 3 V에서 충방전 전류밀도가 1C($17.5A/m^2$), 3C($52.5A/m^2$) 와 5C($87.5A/m^2$)에 대하여, 298K의 등온계와 충방전 전류밀도 별 발열계로 각각 설정하였다. 등온계와 발열계에서 모두 충방전 전류밀도가 높을수록 전지의 용량은 감소되는 것으로 나타났다. 등온계에 비하여 발열계에서 충방전 시간이 증가하였으며, 이는 발열에 의한 온도의 증가로 인해 전극의 평형전위가 감소하고, 리튬이온의 확산계수가 증가하기 때문인 것으로 고려된다. 또한, 리튬이온전지의 충전과 방전에 의한 열 발생 영향을 제어하기 위한 냉각효과를 분석하였다.

• Journal of information and communication convergence engineering
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• 제5권3호
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• pp.215-218
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• 2007

In this paper, amorphous semiconductor and insulator thin film are etched using reactive ion etcher. At that time, we experiment in various RIE conditions (chamber pressure, gas flow rate, rf power, temperature) that have effects on quality of thin film. The using gases are $CF_4,\;CF_4+O_2,\;CCl_2F_2,\;CHF_3$ gases. The etching of a-Si:H thin film use $CF_4,\;CF_4+O_2$ gases and the etching of $a-SiO_2,\;a-SiN_x$ thin film use $CCl_2F_2,\;CHF_3$ gases. The $CCl_2F_2$ gas is particularly excellent because the selectivity of between a-Si:H thin film and $a-SiN_x$ thin film is 6:1. We made precise condition on dry etching with uniformity of 5%. If this dry etching condition is used, that process can acquire high yield and can cut down process cost.

• Journal of Electrochemical Science and Technology
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• 제13권2호
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• pp.254-260
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• 2022

Trimethylammonium tetrafluoroborate (TriMA BF₄), consisting of the smallest trialkylammonium ion, was investigated for use in electrochemical double-layer capacitors. Despite the presence of a proton in TriMA⁺, cycle life tests in acetonitrile (AN) and -butyrolactone (GBL) showed a good capacity retention with a 1.8 V cut-off voltage. The rate of electrolysis of TriMA BF₄ in GBL was lower than that in AN because of the lower conductivity in GBL. As a consequence, the cells based on GBL achieved a higher capacitance and longer life than those with AN. TriMA BF₄ had a higher conductivity and lower viscosity than the quaternary salt tetraethylammonium tetrafluoroborate in GBL, as well as higher ionic mobility, these factors resulted in a higher rate capability.