• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 추계총회 및 연구발표회 초록집
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• pp.62.2-62
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• 2003

• Animal Systematics, Evolution and Diversity
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• 제24권1호
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• pp.59-68
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• 2008

Cerceris rubida and C. verhoeffi are reported from Korea for the first time with detailed redescriptions. We also provide a checklist of Korean Philanthidae including 24 species.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2012년도 춘계학술논문집 1부
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• pp.431-435
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• 2012

Aluminum containing mesoporous molecular sieves Al-SBA-1 ($n_{Si}/n_{Al}$= 2, 5, 10, 15) was synthesized with a one-step method, and the catalyst was characterized with powder X-ray diffraction (XRD), nitrogen adsorption-desorption, thermogravimetric analysis (TGA), scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FT-IR). Finally, we studied the catalytic activities of Al-SBA-1 molecular sieves in Pechmann reaction of 3-methoxyphenol and Ethyl acetoacetate to get 7-methoxy-4-methyl coumarin. Four parameters reaction temperature, time, catalyst weight and reactants ratio were optimized.

• Carbon letters
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• 제5권4호
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• pp.191-196
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• 2004

The electrochemical removal (ECR) of water pollutants by activated carbon fiber (ACF) electrodes from wastewater was investigated over wide range of electrochemical reaction time. The ECR capacities of ACF electrodes were associated with their internal porosity and were related to physical properties and to reaction time. And, surface morphologies and elemental analysis for the ACFs after electrochemical reaction are investigated by SEM and EDX to explain the changes in adsorption properties. The FT-IR spectra of ACFs for the investigation of functional groups show that the electrochemical treatment is consequently associated with the homogeneous removal of pollutants with the increasing surface reactivity of the activated carbon fiber surfaces. The ACFs were electrochemically reacted to waste water to investigate the removal efficiency for the COD, T-N and T-P. From these removal results of pollutants using ACFs substrate, satisfactory removal performance was obtained. The outstanding removal effects of the ACFs substrate were determined by the properties of the material for adsorption and trapping of organics, and catalytic effects.

• 항공우주시스템공학회지
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• 제10권1호
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• pp.1-7
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• 2016

During flight of the aircraft, the vortex merging phenomenon appears under the certain condition between co-rotating vortices which were generated at the wing tip and lifting-surface. And then these merged vortices at both sides show counter-rotating pattern to affect on the downstream of the aircraft. In this paper, the numerical simulations are conducted assuming this phenomenon in two-dimensional co-rotating or counter-rotating vortices pairs. Two-dimensional incompressible Navier-Stokes equations were converted into Vorticity-Streamfunction form and the Galerkin spectral method was adopted. The third order Runge-Kutta method was used for time integration. The effects on the vortex merger and degree of vortex merger were investigated according to time, Reynolds number, and changes in the distance between two vortices.

• 한국세라믹학회지
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• 제48권2호
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• pp.147-151
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• 2011

In this study, we prepared graphene by using the modified Hummers-Offeman method and then introduced the metals (Pt, Pd and Fe) for dispersion on the surface of the graphene for synthesis of metal-graphene composites. The characterization of the prepared graphene and metal-graphene composites was performed by X-ray diffraction (XRD), scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and transmission electron microscopy (TEM). According to the results, it can be observed that the prepared graphene consists of thin stacked flakes of shapes having a well-defined multilayered structure at the edge. And the metal particles are dispersed uniformly on the surface of the graphene with an average particle size of 20 nm.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2008년도 추계학술발표논문집
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• pp.390-393
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• 2008

본 합성법으로 제조된 메조포러스 실리카는 X-선 회절패턴, TEM, FT-IR, BET 측정 결과 MCM-41의 특성과 동일하게 나타났다. 연구 결과 PH조절에 따른 MCM의 특성을 표면적, 기공분포, XRD회절분석, SEM, TEM의 결과를 이용하여 파악하였으며, 쌀겨로부터 규소원을 MCM-41의 합성이 가능함을 알 수 있었다. PH조절에 황산과 아세트산 두 가지의 산을 사용하였다. 그 결과 황산보다는 아세트산을 사용하였을 때 수율과 주기공 크기가 증가하는것을 알수있었다. 아세트산을 이용한 경우 팽윤 효과를 나타내어 주기공 크기가 커진 것이다.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2011년도 춘계학술논문집 1부
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• pp.144-146
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• 2011

Al-MCM-48 molecular sieves (Si/Al = 25, 50, 75 and 100) were synthesized hydrothermally using cetyltrimethyl ammonium bromide as the structure directing template. The orderly arrangement of mesopores was evident from the low angle X-ray diffraction patterns and TEM images. The catalytic performance was evaluated in the vapour phase isopropylation of phenol with isopropyl acetate. Phenol conversion decreased with increase in the Si/Al ratio of the catalysts. The major reaction product was 4-isopropyl phenol (selectivity: 78%). Delocalization of phenolic oxygen electron pair over the aromatic ring promoted para-selective alkylation. Such delocalization could be aided by the hydrophilic surface of the molecular sieves. Though ester was used as the alkylating agent, phenyl isopropyl ether was not formed

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2009년도 춘계학술발표논문집
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• pp.898-901
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• 2009

액상 보일러 및 가열로 등에서 발생되어 연소기기 내부에 침적되는 슈트, 슬래그, 크랭커, 회분, 산화물의 on-line 세정을 위한 세정제의 제조에 대한 연구를 수행하였다. 고상, 액상, 기상연료를 사용하는 보일러 및 가열로에 생성되는 슈트, 슬래그, 크랭커, 회분, 산화물을 제거하는 기술은 보일러 및 가열로의 가동 중단 후 작업자들에 의한 기계적인 처리를 통하여 슈트를 제거하는 기술을 대치할 수 있고 보일러의 중단이 없는 상태에서 침적물을 세정할 수 있는 세정제의 최적고성에 대한 연구를 수행하였다. 주 세정제로는 질산암모늄을 사용하였으며, 각종 전이금속에 의한 연향을 연구하였다.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2009년도 춘계학술발표논문집
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• pp.91-94
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• 2009

쌀겨회재에서 추출한 실리카원을 이용하여 메조포러스실리카 SBA-15를 합성하였으며, 이산화탄소에 대한 높은 선택성을 나타내는 아민기를 우수한 구조성을 지닌 메조포러스실리카에 그라프팅하였다. 아민기가 그라프팅된 메조포러스실리카에 높은 흡착능을 도출하기 위해서 dendrimer/SBA-15를 반응조건에 따라 합성하였다. 이와 같이 합성된 고체흡수제는 X-선 회절분석, 질소 흡,탈착 곡선, 분광분석 (FT-IR)등의 특성 분석을 수행하였고, 열중량반응기 및 충전층 반응기에서 이산화탄소 흡수실험을 수행하였다.