• 제목/요약/키워드: Hanseo

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Fabrication and Physicochemical Properties of Carbon/Titania/Bentonite Monolith for Architecture

  • Oh, Won-Chun;Choi, Jong-Geun;Song, Da-Ye;Kim, Ha-Rry;Chen, Ming-Liang;Zhang, Feng-Jun;Park, Tong-So
    • 한국재료학회지
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    • 제20권3호
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    • pp.167-173
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    • 2010
  • In this study, we used activated carbon (AC) and titanium oxysulfate as a titanium precursor to prepare carbon/titania composites. We then mixed it with bentonite in different ratios to make a carbon/titania/bentonite monolith for use in architecture bricks by using Phenolic rosin (PR) as a bonding agent. The physicochemical properties of the prepared composites were analyzed by BET surface area, scanning electron microscopy (SEM), X-ray diffraction (XRD), energy dispersive X-ray analysis (EDX), self-cleaning effect and bactericidal tests. The BET surface areas increased as the ratio of carbon/titania composites increased. The SEM microscopy showed that the $TiO_2$ and bentonite were coated on the surface of the AC. The XRD patterns showed a mixture structure of anatase and rutile of $TiO_2$ with a clear $SiO_2$ structure. The EDX spectra of the carbon/titania/bentonite monolith confirmed the presence of various elements, namely C, O, Ti and Si, as well as other, impure elements. Moreover, to determine the self-cleaning effect of the carbon/titania/bentonite monolith, we used methylene blue (MB, $C_{16}H_{18}N_3S{\cdot}Cl{\cdot}3H_2O$) in an aqueous solution under the irradiation of visible light. Accordingly, all of the samples had excellent degradation of the MB solution. Furthermore, it was observed that the composites with sunlight irradiation had a greater effect on E. coli than any other experimental conditions.

Additional Effect of Zeolite Based on Bactericidal Activated Carbon Spheres with Enhanced Adsorption Effect and Higher Ignition Temperature

  • Zhu, Lei;Ye, Shu;Asghar, Ali;Bang, Seong-Ho;Oh, Won-Chun
    • 한국세라믹학회지
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    • 제53권1호
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    • pp.68-74
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    • 2016
  • In this study, the fabrication of zeolite combined activated carbon spherical samples was carried out as follows. Briefly, ZSM-5 zeolite and activated carbon were composed as main absorbent materials; by controlling the weight percentage of zeolite and binder materials, a series of spherical samples (AZP 4, 6, 8) were prepared. These spherical samples were characterized by BET, XRD, SEM, EDX, and pressure drop; benzene and iodine adsorption tests, bactericidal effect test, and ignition temperature test were also performed. The adsorption capability was found to depend on the BET surface area; the spherical samples AZP6 with high BET surface area of $1011m^2/g$ not only exhibited excellent removal effects for benzene (24.9%) and iodine (920mg/g) but also a good bactericidal effect. The enhanced ignition temperature may be attributed to the homogeneous dispersion conditions and the proper weight percentage ratio between zeolite and activated carbon.

Aluminum Effect as Additive Material in Expanded Graphite/Sand Composite for High Thermal Conductivity

  • Areerob, Yonrapach;Nguyen, Dinh Cung Tien;Dowla, Biswas Md Rokon;Ali, Asghar;Oh, Won-Chun
    • 한국재료학회지
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    • 제27권8호
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    • pp.422-430
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    • 2017
  • Al/expanded graphite was successfully synthesized through a facile method including ultrasonic and heat treatment. In the well-designed three dimensional structure, expanded graphite(EG) works as a conductive matrix to support coated Al particles. The effects of the fabrication parameters on the microstructures and thermal conductivities of these composites were investigated. As a result, it was found that composites with graphite volume fraction of 17.4-69.4 % sintered at $600^{\circ}C$/45MPa exhibit in-plane thermal conductivities of 380-940 W/mK, over 90 % of the predictions by rule of mixture. According to the non-destructive analysis results, the synergistic enhancement was caused by the formation of efficient thermally conductive pathways due to the hybrid of the differently sized EG. The structure integrates the advantages of expanded graphite as a conductive support, preserving the electrode activity and integrity and improving the electrochemical performance.

Synthesis of Expanded Graphite-Titanium Oxide Composite and its Photocatalytic Performance

  • Oh, Won-Chun;Choi, Jong-Geun;Zhang, Feng-Jun;Go, Yu-Gyoung;Chen, Ming-Liang
    • 한국세라믹학회지
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    • 제47권3호
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    • pp.210-215
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    • 2010
  • In this study, an expanded graphite-titanium oxide composite is developed from expanded graphite (EG) and titanium n-butoxide (TNB). EG is synthesized by chemical intercalation of natural graphite (NG) and rapid expansion at high temperature. TNB is used as the titanium source. The performances of the prepared EG-$TiO_2$ composite are characterized by BET surface area measurements, scan electron microscope (SEM), X-ray diffraction patterns (XRD) and energy dispersive X-ray analysis (EDX). The catalytic activities of the EG-$TiO_2$ composite are investigated by analysis of the degradation of methylene blue (MB) in aqueous solution under irradiation of UV light. Compared with the pristine $TiO_2$ and activity carbon-$TiO_2$ (AC-$TiO_2$) composite, the EG-$TiO_2$ composite shows very high efficiency against MB solution, and the EG could improve the photocatalytic effect of $TiO_2$ in the MB degradation reaction under the irradiation of UV light.

Li, Zr 담지 메조포러스 실리카 합성 : One pot 합성 및 저온 이산화탄소 흡착 응용 (Li, Zr doped mesoporous silica: One pot synthesis and its application to $CO_2$ adsorption at low temperature)

  • 마니 기니쉬;말간단 바기아락스미;팽 메이메이;푸시파라지 헤마라다;장현태
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2010년도 추계학술발표논문집 1부
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    • pp.313-317
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    • 2010
  • Li, Zr doped mesoporous silica was synthesized in one pot and investigated for low temperature $CO_2$ adsorption. Herein CTAB and TEOS are used as structural directing agent and silica source respectively. The characteristics of the material was obtained from FT IR, XRD, SEM, TG and BET results. ICP AES results revealed the presence of lithium and zirconium. The material possesses high surface area ($962.22m^2g^{-1}$) with mono dispersed particles of about 2 nm. The maximum $CO_2$ adsorption capacity is 5 wt % (50 mg/g) of $CO_2$/g of sorbent at $25^{\circ}C$, which is regenerable at $200^{\circ}C$. This regeneration temperature of the adsorbent is lower than the reported lithium zirconium silicate powder. Until now, there is no report for the synthesis of Li, Zr doped mesoporous silica. The performance studies illustrate that Li, Zr doped mesoporous silica is tunable, regenerable, recyclable and selective sorbent and hence found to be a promising candidate for $CO_2$ adsorption.

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Ce 담지 NaZSM-5의 이산화타소 흡착 특성 ($CO_2$ adsorption on ceria impregnated)

  • 푸시파라지 헤마라다;마니 기니쉬;말간단 바기아락스미;팽 메이메이;장현태
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2010년도 추계학술발표논문집 1부
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    • pp.318-322
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    • 2010
  • NaZSM 5 was synthesized in an alkaline medium and impregnated with cerium oxide by wet method using cerium nitrate as the source for cerium. There TGA results shows decomposition of nitrate at $200^{\circ}C$. The ceria impregnated ZSM 5 materials were designated as NaZSM 5 (X) where X is the percent ceria impregnated (3, 5, 7, 11, 19%). They were characterized by XRD, SEM, EDAX, BET techniques. XRD analysis showed decrease in intensity of the patterns with the increase in the ceria loading but crystallization of ceria to larger size is evident for 11 and 19% loading. The surface area and pore volume decreased with increase in ceria loading. The maximum adsorption capacity of NaZSM 5 (5%) is 100.2 mg/g of sorbent. The ceria impregnated NaZSM 5's were found to be regenerable, selective and recyclable.

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연안역 비점오염관리 외국사례 조사 (Introduction of Coastal Area Management Program in Other Countries)

  • 우강화;이치타오;한봉윤;김연석;김영철
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2009년도 추계학술발표논문집
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    • pp.358-362
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    • 2009
  • The coastal zone is the transitional area between land and sea. It plays an important role in the land-sea ecosystem. Unfortunately, most of the world's coastal areas are polluted due to the human being activities. Pollution and development are changing coastal habitats, and feeding and nursery areas are being destroyed, reducing fish and wildlife populations. The pollution in coastal areas is becoming a global environmental problem, more and more attention has been paid to coastal areas. America passed the Coastal Zone Management Act (CZMA) in 1972, and from then, CZMA outlined and conducted the National Coastal Zone Management Program and the National Estuarine Research Reserve System which including 34 projects. And England established "the Crouch & Roach Estuary Project" in 2003, and "South East Coastal and Marine Project" was started in 2007 in responding to the non-point pollutants challenge.

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전이금속 담지 제올라이트 분자체 이용한 CO 흡착특성 (Performance of CO adsorption on Transition metal impregnated zeolite molecular seive)

  • 이주보;정의민;김대경;;장현태;차왕석
    • 한국산학기술학회:학술대회논문집
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    • 한국산학기술학회 2012년도 춘계학술논문집 1부
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    • pp.33-35
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    • 2012
  • 본 연구에서는 전이금속 Cu, Mn이 함침된 제올라이트를 사용하여 일산화탄소의 흡착능을 연구하였다. 금속 복합 산화물촉매 제조는 Cu, Mn을 서로 다른 비율로 물리 혼합하여 지지체에 담지하였다. 제올라이트 분자체는 상용 13X를 사용하였다. 함침방법은 과잉용액 함침법을 사용하였고, 건조 후 소성 하여 산화물 형태로 담지하였다. 합성된 개질 흡착제의 표면특성 분석은 $N_2$흡착 및 탈착곡선을 통한 질소흡착 특성 분석으로 기공크기, 기공분포, 비표면적을 구하였으며, FT-IR, X-선 회절분석, 전자주사현미경, $NH_3$-TPD/TPR 으로 특성을 분석하였다. 흡착 실험은 고정층 반응기에서 수행하였으며, 내경 4 mm 석영관에 흡착제를 충진하고 흡착파과곡선을 Gas Chromatograph로 측정하여 Cu-Mn 제올라이트 촉매의 일산화탄소 흡착 성능을 연구하였다. Cu-Mn 함량 비율과 흡착조업조건에 따른 흡착능을 측정하여 최적 흡착조건을 구하였다.

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Facile Preparation of Ag2S-CNT Nanocomposites with Enhanced Photo-catalytic Activity

  • Meng, Ze-Da;Sarkar, Sourav;Zhu, Lei;Ullah, Kefayat;Ye, Shu;Oh, Won-Chun
    • 한국세라믹학회지
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    • 제51권1호
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    • pp.1-6
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    • 2014
  • Here we report improved photo-catalytic effect of $Ag_2S$ under visible light using carbon nano-tubes (CNT) modified with $Ag_2S$ nanoparticles. The optical properties, structural properties and compositional analysis, as well as the photo-electrochemical properties of the prepared composites were investigated. It was found that the photocurrent density, and the photo-catalytic effect, was increased by modification of CNT in this way. Compared with the separate effects of $Ag_2S$ and CNT nanoparticles, the photocatalytic effect of CNT-modified-with-$Ag_2S$ composites, increased significantly due to a synergistic effect between the CNT and the $Ag_2S$ nanoparticles.

Controlling the Porosity of Particle Stabilized Al2O3 Based Ceramics

  • Pokhrel, Ashish;Park, Jung-Gyu;Jho, Gae-Hyong;Kim, Jin-Young;Kim, Ik-Jin
    • 한국세라믹학회지
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    • 제48권6호
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    • pp.600-603
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    • 2011
  • The microstructure of particle stabilized wet foams can be tailored by using parameters including the amphiphile concentration, contact angle, and surface tension. The influence of these parameters on the porosity is satisfactorily described in terms of a combined influence of the contact angle and surface tension of the initial suspensions that are directly affected by the amphiphile concentration. The resulting macroporous structures exhibited a total porosity of 82%. The foam cells were predominantly closed due to the air bubbles of the original wet foams being completely covered.