• Journal of the Korean Crystal Growth and Crystal Technology
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• v.8 no.2
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• pp.342-342
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• 1998

The effect of pH on the dehydration reaction of TiCl₄solution. KOH and HCl were used as a accelerater and retarder in dehydration. Results are follow. Neutralization point is pH 7.4 in the system of $TiCl_4-KOH$ and the production which is produced at acidic side is Ti-gel of poly metatitanic acid. The production which is produced at alkalic side is aligomer and crystalline potasium titanate is not detected.

• Journal of the Korean Ceramic Society
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• v.36 no.6
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• pp.577-582
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• 1999

Activated carbon fibers were prepared from stabilized PAN fibers by chemical activation using hydroxide. The variations in specific surface area amount of iodine adsorption micro-structure and pore size distribution in the activated carbon fibers after the activation process were discussed. In the chemical activation using potassium hydroxide specific surface area of about 2545m2/g and amount of iodine adsorption of 2049 mg/g were obtained at the condition of KOH/fiber ratio of 1 and 800$^{\circ}C$ Nitrogen adsorption isotherms for PAN based activated carbon fibers showed the type I in the Brunauer-Deming-Deming-Teller classification indicating the micro-pores consisting the activated fibers.

• 한국신재생에너지학회:학술대회논문집
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• 2009.11a
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• pp.524-526
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• 2009

바이오디젤은 식물성 기름이나 동물성 지방과 같은 재생 가능한 원료로부터 전이에스테르화 반응을 통해 생산되는 대체 연료이다. 본 연구에서는 NaX 제올라이트 촉매에 염기성 물질인 KOH를 담지한 후 소성온도에 따라 제조된 촉매를 사용하여 바이오디젤 제조 특성을 조사하였다. 제조된 촉매의 결정구조와 성분을 분석하기위해 XRD, SEM 을 이용하였으며, 표면적을 측정하기 위해 BET 를 사용하였다. 실험결과 소성온도가 $500^{\circ}C$일 때 30wt% KOH/NaX 제올라이트 촉매내 K 함량이 가장 높았고, 이때 70%이상의 높은 바이오디젤 수율을 얻을 수 있었다.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2006.05a
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• pp.216-220
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• 2006

평면 광 신호 분리기와 광 케이블의 정밀결합을 위하여 V-groove를 제작하였다. V-groove 는 실리콘웨이퍼 (100) 면을 KOH 용액으로 선택적 습식 식각하여 제작되었다. V-groove 를 효과적으로 제작하기 위하여 KOH 의 조성 (10, 20, 30, 33, 40 wt%)과 온도 (50, 60, 70, $80^{\circ}C$)를 변화시켜 식각률과 표면조도를 측정하였다. 식각률은 $80^{\circ}C$에서 20 wt.% KOH 로 식각했을 경우 $1.84{\mu}m/min$ 로 가장 빨랐으며, 표면조도는 $80^{\circ}C$에서 33 wt.% KOH로 식각했을 경우 1.6nm로 가장 양호하였다.

• Journal of the Korean Vacuum Society
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• v.8 no.2
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• pp.127-135
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• 1999

Nickel oxide films were prepard by using the electron beam evaporation technique. Coloring and bleaching experiments for cyclic durability were repeated in KOH electrolyte by cyclic voltammetry. Visible spectrophtometry was used to assess the stability of the transmittance in the degraded films. X-ray photoelectron spectroscopy results showed that the grain surface are oxygen-rich compared to the grain interiors in a NiO film. Open circuit memory of colored films is about 400hours in lN KOH. The rate of self discharge was evaluated by measuring the transmittance at 550nm of a fully oxidized NiO film. The rate of self discharge was increased polynomially with time and the film is nearly bleached after about 400hours. It was also found that the degraded film by repeated cycles in the KOH solution changed the grain shape of film surface The film prepared under a vacuum pressure of $3\times10^{-4}$ mbar was found to be rather stable when subjected to the repeated coloring and bleaching cycles in KOH electrolyte. Band theory applied to explain the electrochromic mechanism was discussed.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.540-540
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• 2008

본 논문에서는 KOH 전해액을 이용하여 Cu 막의 부동태층의 형성을 I-V를 통해 평가하였으며, 이를 토대로 최적화된 전압과 시간을 알 수 있었다. 또한, SEM, EDS, XRD를 통해 표면 품질 및 성분 분석을 비교 분석하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1997.11a
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• pp.393-396
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• 1997

Electro Discharge Machining (EDM) is a so-call non-conventional machining technique. This paper presents the experimental results of an EDM technique for the fabircation of microholes on #7440 pyrex glans. With various applied voltages and at various concentration of KOH solution, the glass substrate have been microdrilled using the copper electrodes of which diameters are 250$\mu\textrm{m}$ to 450$\mu\textrm{m}$, respectively. The machined throughholes have been observed the top diameter, the bottom diameter, hollow width and hole diameter of the hole, and machining time hale been measured. The experimental results show that the machining time decreases as the concentration of KOH solution increases or the applied voltage increase. Also, The top diameter increases as the concentration of KOH solution decreases or the allied voltage increases. The bottom and hollow width decreases as the of KOH solution increases or the applied voltage decreases.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.24 no.10
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• pp.779-783
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• 2011

The morphology of etch pits in commercial 4H-SiC epi-wafer were investigated by molten-KOH etching. The etching process was optimized in $525{\sim}570^{\circ}C$ at 2~10 min and the novel type of etch pits was revealed. This type of etch pits have been considered as TED (threading edge dislocation) II, its origin and nature, however, are not reported yet. In this work, the morphology and evolution of etch pits during epitaxial growth were analyzed and the different behavior between TED and TEDII was discussed.

• Proceedings of the Materials Research Society of Korea Conference
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• 2005.05a
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• pp.118-118
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• 2005

• Proceedings of the Materials Research Society of Korea Conference
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• 2002.11a
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• pp.133-133
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• 2002