• Journal of the Korean Vacuum Society
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• v.7 no.3
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• pp.221-228
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• 1998

Enhancement of adhesion between polymer films and metal films are obtained by forming the hydrophilic functional groups on the polymer surfaces by ion assisted reaction which uses ion beam in reactive gas environments. In ion assisted reaction, ion dose, blown gas flow rate and ion energy were changed from $5\times 10^{14}$ to $1\times 10^{17}\textrm{ions/cm}^2$, from 0 to 8 sccm, and 0.3 to 1.2 kV, respectively. Wetting angle of water on polymer films modified by $ Ar^+$ ion without blowing oxygen decreases to ~$40^{\circ}$. Contact angle of water on polymer films modified by $ Ar^+$ ion with blowing oxygen decreases to ~$20^{\circ}$, and the surface free energy increases to ~70 dyne/$\textrm{cm}^2$. However, contact angle of water on polytetraflouroethylene (PTFE) modified by ion assisted reaction increases with ion dose. The adhesion strength of metal film deposited on the polymer surface was investigated. In the case of the metal film deposited on the untreated polymers, the metal films are detached from the polymer surface. While, In the case of the metal film deposited on the polymers treated by ion assisted reaction, the metal films are strongly adhere to the polymer surfaces.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.05a
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• pp.191-191
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• 2009

최근 많은 환경오염물질을 제거하기 위한 방법으로 광촉매를 이용한 기술들이 다양하게 활용되고 있다. 본 연구에서는 높은 비표면적을 갖는 관촉매를 제조하기 위해, 전기화학적인 방법인 양극 산화법을 사용하여 기지 Ti 금속 표면에 pore 형태의 광촉매용 $TiO_2$를 제조하고, 염료분해 반응을 통해 광촉매의 효율을 조사하였다. 또한 염료분해 효율을 높이기 위해 $Eu(NO_3)_3$를 첨가하여 염료분해 반응에 미치는 영향에 대해 조사하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2011.05a
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• pp.140-140
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• 2011

최근 많은 환경오염물질을 제거하기 위한 방법으로 광촉매를 이용한 기술들이 다양하게 활용되고 있다. 본 연구에서는 높은 비표면적을 갖는 광촉매를 제조하기 위해, 전기화학적 방법인 양극 산화법을 통하여 기지 Ti 금속 표면에 nanotube 형태의 광촉매용 $TiO_2$를 제조하고, 염료분해 반응을 통해 광촉매의 효율을 조사하였다. 또한 염료분해 효율을 높이기 위해 Ag와 Pd를 도핑하여 염료분해 반응에 미치는 영향에 대해 조사하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2009.10a
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• pp.190-191
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• 2009

최근 환경오염물질을 제거하기 위한 방법으로 광촉매를 이용한 기술들이 다양하게 활용되고 있다. 본 연구에서는 높은 비표면적을 갖는 광촉매를 제조하기 위해, 전기화학적인 방법인 양극 산화법을 사용하여 기지 Ti 금속 표면에 기공성 형태의 광촉매용 $TiO_2$를 제조하고, 염료분해 반응을 통해 광촉매의 효율을 조사하였다. 또한 염료분해 효율을 높이기 위해 $H_3(BO_3)_3$를 첨가하여 염료분해 반응에 미치는 영향에 대해 조사하였다.

• Economic and Environmental Geology
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• v.44 no.2
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• pp.123-133
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• 2011

The lab scale experiments to investigate the geochemical reaction among supercritical $CO_2$-mineral-brine which occurs at $CO_2$ sequestration sites were performed. High pressurized cell system (l00 bar and $50^{\circ}C$) was designed to create supercritical $CO_2$ in the cell, simulating the sub-surface $CO_2$ storage site. From the high pressurized cell experiment, the surface changes of Ca-feldspar, amphibole (tremolite) and olivine, resulted from the supercritical $CO_2$-mineral-brine reaction, were observed and the dissolution of minerals into the brine was also investigated. The mineral slabs were polished and three locations on the surface were randomly selected for the image analysis of SPM and the surface roughness value (SRV) of those locations were calculated to quantify the change of mineral surface for 30 days. At a certain time interval, SPM images and SRVs of the same mineral surface were acquired. The secondary minerals precipitated on the mineral surfaces were also analyzed on SEM/EDS after the experiment. From the experiments, the average SRV of Ca-feldspar increased from 2.77 nm to 20.87 nm for 30 days, suggesting that the dissolution of Ca-feldspar occurs in active when the feldspars contact with supercritical $CO_2$ and brine. For the amphibole, the average SRV increased from 2.54 nm to 8.31 nm and for the olivine from 0.77 nm to 11.03 run. For the Ca-feldspar, $Ca^{2+}$, $Na^+$, $Fe^{2+}$, $Si^{4+}$, $K^+$ and $Mg^{2+}$ were dissolved in the highest order and $Si^{4+}$, $Ca^{2+}$, $Fe^{2+}$ and $Mg^{2+}$ for the amphibole. Fe (or Mg) - oxides were precipitated as the secondary minerals on the surfaces of amphibole and olivine after 30 days reaction. Results suggested that $Ca^{2+}$, $Fe^{2+}$ and $Mg^{2+}$ rich minerals would be significantly weathered when it contacts with the supercritical $CO_2$ and brine at $CO_2$ sequestration sites.

• Korean Chemical Engineering Research
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• v.61 no.4
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• pp.604-610
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• 2023

The nitrogen reduction reaction (NRR), which produces NH₃ by reducing N₂ under ambient conditions, is attracting attention as a promising technology that can reduce energy consumption in industrial processes. We investigated the adsorption behaviors at various active sites on the Ni (100) surface, which is widely used among catalytic metal surfaces capable of adsorbing and activating N₂, based on density-functional theory calculations. We also investigated two N₂ adsorption structures, so-called end-on and side-on structures. We find that for the end-on case, N₂ is adsorbed on a top site, and the reaction proceeded in a distal pathway, while for the side-on case, N₂ is adsorbed on a bridge site, and the reaction proceeded with enzymatic pathway. Finally, this study provides insight into the adsorption of metal catalyst surfaces for the NRR reactions based on the calculated Gibbs free energy profiles of the thermodynamically most favorable pathways.

• Food Engineering Progress
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• v.15 no.2
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• pp.97-115
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• 2011

A review about the application of response surface methodology in the optimization of food technology is presented. The theoretical principles of response surface methodology and steps for its application are described. The response surface methodologies : three-level full factorial, central composite, Box-Behnken, and Doehlert designs are compared in terms of characteristics and efficiency. Furthermore, recent references of their uses in food technology are presented. A comparison between the response surface designs (three-level full factorial, central composite, Box-Behnken and Doehlert design) has demonstrated that the Box-Behnken and Doehlert designs are slightly more efficient than the central composite design but much more efficient than the three-level full factorial designs.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.33 no.10
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• pp.68-74
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• 2005

Optimal shape of a typical ramjet intake is examined numerically to maximize the total pressure recovery. A response surface method is introduced to approximately predict its performance with respect to the design parameters over the each design domain. The first deflection angle of ramp, the area of inlet throat, and the diffuser angle are chosen as a design parameter. ANOVA is used to verify the trustability of the achieved response surface. The total pressure recovery of the optimum model, compared to that of the base model, is increased by 36%. The loss of viscosity through the diffuser is estimated less than 5%.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.164.2-164.2
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• 2016

수산화인회석(Hydroxyapatite)는 뼈와 이빨의 무기물의 주성분으로서 칼슘과 인산염으로 구성된다. 본 연구에서는 특정 농도의 염기조건 (10 M NaOH)에서 수열합성법 (hydrothermal method)을 이용하여 수산 화인회석을 합성하였다. 합성된 샘플은 XRD 패턴 및 TEM 이미지 분석을 통하여 단결정성과 일정한 형태를 지닌 수산화인회석이 합성된 것을 확인하였다. 수산화인회석의 표면에 루테늄을 도입하기 위하여 이온교환 반응 과 열처리 과정을 이용하였다. 도입된 루테늄 나노 입자는 TEM 이미지 분석을 통하여 확인하였으며, 일차알콜과 이차알콜등의 유기 산화반응에 촉매로서 사용하였다.

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.331-331
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• 2015

차세대 원자로 핵연료의 성능을 제한하는 금속연료-피복관 상호반응 현상(FCCI)을 방지하기 위한 방안으로 Cr 도금기술의 적용성을 연구하였다. 도금 성능을 평가하기 위한 예비 시험 결과 Cr 도금층은 핵연료와 피복관의 상호반응을 억제함이 확인되었다. 도금층 성질을 개선하기 위한 연구와 함께 Cr층을 피복관 내면에 도금하는 연구를 수행하였다.