• 상하수도학회지
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• 제14권4호
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• pp.350-355
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• 2000

Powdered activated carbon(PAC) is widely used to control 2-MIB와 geosmin causing earthy-musty odor in water supplies. It was known that chlorine is one of the chemicals often come into contact with activated carbon. But activated carbon react with chlorine and surface oxide accumulate on carbon surface. As result, adsorption capacity of activated carbon is reduced. To investigate the effect of chlorine on the PAC's ability to adsorb 2-MIB and Geosmin, a series of experiments was carried out to show (1) the effect of aqueous chlorine doses on the ability of PAC to adsorb 2-MIB and Geosmin from Lake Heodong water. (2) the effect of delaying the chlorine addition after PAC had been added (to simulate the effect of using an alternative point of chlorine addition). As a result of experiment, as chlorine dose increased correspondingly decreased the capacity of activated carbon to adsorb 2-MIB and geosmin. Even though previously adsorbed 2-MIB and geosmin released, as result of the application of delaying the chlorine adding was more beneficial than simultaneous adding chlorine with PAC.

• 한국세라믹학회지
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• 제56권5호
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• pp.513-520
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• 2019

This study reports the improvement of mechanical properties of Al₂O₃ porous ceramics from colloidal suspension with the addition of carbon fiber by direct foaming. The initial colloidal suspension of Al₂O₃ was partially hydrophobized by surfactant to stabilize wet foam with the addition of carbon fiber from 2 to 8 wt% as stabilizer. The influence of carbon fiber on the air content, bubble size, pore size and pore distribution in terms of wet foam stability and physical properties of porous ceramics were discussed. The viscosity of the colloidal suspension was increased giving solid like properties with the increased in carbon fiber content. The mechanical properties of the sintered porous samples were investigated by Hertzian indentation test. The results show the wet foam stability of more than 90% corresponds to compressive loading of 156.48 N and elastic modulus of 57.44 MPa of sintered sample with 8 wt% of carbon fiber content.

• 한국세라믹학회지
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• 제33권7호
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• pp.816-822
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• 1996

서로 다른 흑연화도를 갖는 furan 수지로 부터 얻어진 무기화합물(SiC, TiO2) 첨가 탄소재료의 산화반응의 흑연구조 의존성에 대하여 살펴보았다. 탄소재료의 산화는 시료의 표면적에 크게 의존하여, 흑연화가 상당히 진행된시료라 할지라도 표면적이 클 때는 살화속도도 빠른 것으로 밝혀졌으며, 단위 중량이 아닌 단위면적당의 산화속도로 바꿔 생각했을 때 흑연화가 진행될 수록 산화반응도 늦어지는 것을 알 수 있었다. 그리고 겉보기 활성화 에너지값으로 부터 생각할 때 흑연(TiO2 첨가시료)과 난층흑연(SiC 첨가시료)이 동일한 반응기구에 의해 산화가 진행되는 것으로 판단되었다. 또한 두종류 이상의 결정구조가 혼재하여 있는 시료의 경우 이들 성분들의 산화속도는 달라 반응의 초기에 흑연으로 결정화된 않은 비정질 탄소 성분이 흑연 성분보다 먼저 선택적으로 산화되는 것을 알 수 있었다.

• Macromolecular Research
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• 제16권3호
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• pp.200-203
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• 2008

A conducting polymer layer was introduced into the pore surface of mesoporous carbon via vapor infiltration of a monomer and subsequent chemical oxidative polymerization. The polypyrrole, conducting polymer has attracted considerable attention due to the high electrical conductivity and stability under ambient conditions. The mesoporous carbon-polypyrrole nanocomposite exhibited the retained porous structure, such as mesoporous carbon with a three-dimensionally connected pore system after intercalation of the polypyrrole layer. In addition, the controllable addition of pyrrole monomer can provide the mesoporous carbon-polypyrrole nanocomposites with a tunable amount of polypyrrole and texture property. The polypyrrole layer improved the electrode performance in the electrochemical double layer capacitor. This improved electrochemical performance was attributed to the high surface area, open pore system with three-dimensionally interconnected mesopores, and reversible redox behavior of the conducting polypyrrole. Furthermore, the correlation between the amount of polypyrrole and capacitance was investigated to check the effect of the polypyrrole layer on the electrochemical performance.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2019년도 추계 학술논문 발표대회
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• pp.172-173
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• 2019

As the damage to fine dust increased, the Republic of Korea designated fine dust as a social disaster. The composition of the fine dust is composed of carbon, sulfate, nitrate, ammonium and minerals. The cause of fine dust is naturally generated by dirt, pollen, etc. In addition, there are artificial causes such as gaseous vehicle exhaust gas emitted from the use of fossil fuel. When fine dust enters the human body through breathing, it causes various respiratory diseases and skin diseases. In IARC, fine dust was designated as a carcinogen group 1. In this research, we tried to adsorb fine dust by physical adsorption using powdered activate carbon. Powdered activate carbon is a powdered activated carbon activated in a carbonized state. Porous material with high specific surface area and low density. Experimental items were tested for density, water absorption, and fine dust concentration according to the PAC addition ratio. Basic experiments were carried out to fabricate the fine dust adsorption matrix.

• 한국분말재료학회지
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• 제5권3호
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• pp.178-183
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• 1998

Ultrafine WC-10wt.%Co cemented carbides powders were synthesized by direct carburization. W-Co composite powders and carbon black powders were mixed by wet ball milling and dried. The mixed powders were heated to 800 $^{\circ}C$ with heating rate of 8.2$^{\circ}C$/min and held for various times in flowing $H_2$. For carbon addition of 140%, the carburization was completed by heating at 80$0^{\circ}C$ for 4 hours. The carburization time decreased with increasing amount of carbon and carburization was completed by heating at 800 $^{\circ}C$ for 2 hours with carbon addition of 150%. WC-10 wt%Co cemented carbides powders fabricated by direct carburization have nanoscale WC($\/leqq$100 nm) size.

• Geomechanics and Engineering
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• 제19권4호
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• pp.361-368
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• 2019

This study aims to evaluate the applicability of a grout material that is mixed with carbon fiber, biogrout, ground granulated blast furnace slag (GGBS) powder and cement. Uniaxial compressive strength tests were performed on homo-gel samples at days of 1, 3, 7, 14 and 28. In addition, the variation of permeability with the mixing ratios was measured. Based on the uniaxial compressive strength test, it was confirmed that the uniaxial compressive strength increased by 1.2times when carbon fiber increased by 1%. In addition, as a result of the permeability test, it was found that when the GGBS increased by 20%, the permeability coefficient decreased by about 1.5times. Therefore, the developed grout material can be used as a cutoff grouting material in the field due to its strength and cut-off effect.

• 한국분말재료학회지
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• 제5권4호
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• pp.265-272
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• 1998

For the purpose of investigating the effect of sintering atmosphere and carbon addition on sintered density and microstructural characteristics, the M3/2 grade high speed steel powders with the addition of carbon are sintered in vacuum and $20%H_2/79%N_2/l%CH_4$ gas atmosphere. With the addition of 0 wt%C, 0.45wt%C and 1.15 wt%C the optimum sintering temperatures decrease down to $1260^{\circ}C$, $1210^{\circ}C$ and $1150^{\circ}C$ respectively for the vacuum sintered specimen, and also decrease down to $1130^{\circ}C$, $1120^{\circ}C$ and $1115^{\circ}C$ for the gas sintered specimen. The threshold temperatures for full densification decrease steeply with increasing carbon content of the sintered specimen, while this temperatures are slowly decreased at high carbon content. The vacuum sintered specimen shows the primary carbides of MC and $M_6C$ type at the optimum sintering temperature, and eutectic carbides of $M_2C$ and Fe-Cr type are produced in the oversintered specimen. The gas sintered specimen exhibits M6C and Fe-Cr type primary carbides at the optimum sintering temperature. The eutectic carbides of $M_6C$ and Fe-Cr type and MX type carbonitride are shown for the oversintered specimen in the gas atmosphere. The hardness of gas sintered specimen shows high value of 830-860 Hv due to the increment of carbide precipitation.

• Journal of Microbiology and Biotechnology
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• 제26권7호
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• pp.1290-1302
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• 2016

Microalgae are being researched for their potential as attractive biofuel feedstock, particularly for their lipid production. For maximizing biofuel production, it is necessary to explore the effects of environmental factors on algal lipid-producing potential. In this study, the effects of nitrogen (N) sources (NO₂-N, NO₃-N, urea-N, NH₄-N, and N-deficiency) and carbon-to-nitrogen ratios (C/N= 0, 1.0, 3.0, and 5.0) on algal lipid-producing potential of Chlorella sp. HQ were investigated. The results showed that for Chlorella growth and lipid accumulation potential, NO₂-N was the best amongst the nitrogen sources, and NO₃-N and urea-N also contributed to algal growth and lipid accumulation potential, but NH₄-N and N-deficiency instead caused inhibitory effects. Moreover, the results indicated that algal lipid-producing potential was related to C/N ratios. With NO₂-N treatment and carbon addition (C/N = 1.0, 3.0, and 5.0), total lipid yield was enhanced by 12.96-20.37%, but triacylglycerol (TAG) yields decreased by 25.52-94.31%. As for NO₃-N treatment, carbon addition led to a 17.82-57.43%/25.86-82.67% reduction of total lipid/TAG yields. When NH₄-N was used as the nitrogen source, total lipid/TAG yields were increased by 46.67-113.33%/28.99-74.76% with carbon addition. The total lipid/TAG yields of urea-N treatment varied with C/N ratios. Overall, the highest TAG yield (TAG yield: 38.75 ± 5.21 mg/l; TAG content: 44.16 ± 4.35%) was achieved under NO₂-N treatment without carbon addition (C/N = 0), the condition that had merit for biofuel production.

• 한국건설순환자원학회논문집
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• 제11권4호
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• pp.493-500
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• 2023

본 연구에서는 전도성 재료를 혼입한 광촉매 보도블록을 제조하여 질소산화물 제거율에 미치는 영향을 살펴보고 내구성이 향상된 블록을 제조하고자 하였다. 광촉매와 전도성 재료인 활성탄소를 혼입시 광촉매 효율이 향상되었으며 전도성 광촉매 콘크리트 블록의 경우 광촉매 콘크리트 블록보다 질소산화물 제거율이 2.5배 정도 향상되었다. 전도성 광촉매 시험편의 질소산화물 제거율이 높게 나타난 것은 전도성 재료인 활성탄소의 영향으로 TiO₂ 광분해로 인한 광전류가 많이 발생한 영향으로 볼 수 있으며 광촉매 시험편과 전도성 광촉매 시험편의 질소산화물 제거율 실험결과와 광전류 시험결과를 비교 분석하였다.