• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2003년도 추계총회 및 연구발표회 초록집
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• pp.166.2-166
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• 2003

• 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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• 제48권4호
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• pp.288-292
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• 2011

In this study, we investigated the mechanical behavior of carbon fiber reinforced silicon carbide composites by indentation stress. Relatively porous and dense fiber reinforced ceramic composites were fabricated by liquid silicon infiltration (LSI) process. Densification of fiber composite was controlled by hardening temperature of preform and consecutive LSI process. Load-displacement curves were obtained during indentation of WC sphere on the carbon fiber reinforced silicon carbide composites. The indentation damages at various loads were observed, and the elastic modulus were predicted from unloading curve of load-displacement curve.

• 한국환경과학회지
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• 제14권12호
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• pp.1163-1170
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• 2005

The microbial adsorption characteristics of two different media for biological treatment were studied using attached diverse microbes onto activated carbon and ceramic. The results in the experiments of the characteristics of physical adhesion on two different media with addition of high and low concentrated substrate in the culture were observed that the efficient of adhesion onto F-400 activated carbon was higher over that of ceramic due to the surface area of media. The irradiation treatment by ultrasonication with 400 W power and 3 min retention time on the media without addition substrate conditions and subsequent mixing throughly the culture showed the highest efficiency of cell detachment on the media. Three different microbes, P. ovalis, A calcoaceticus, and B. subtillis were used for the study of the characteristics of microbial adhesion on the media. p ovalis showed the highest adhesion capability while B. subtillis showed the lowest capability adhesion onto media either addition of substrate in the culture. The mixed bacterial culture showed $10\%$ lower removal efficiency of DOC in the low concentrated substrate culture compared to the single pure culture. Whileas, it did not show significant difference between two cultures at high concentrated substrate. It was also observed same population density of microorganism by counting of microbes adhered to microbial media with an ultrasound treatment.

• 한국분말재료학회지
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• 제26권6호
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• pp.502-507
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• 2019

Macro-porous carbon foams are fabricated using cured spherical phenolic resin particles as a matrix and furfuryl alcohol as a binder through a simple casting molding. Different sizes of the phenolic resin particles from 100-450 ㎛ are used to control the pore size and structure. Ethylene glycol is additionally added as a pore-forming agent and oxalic acid is used as an initiator for polymerization of furfuryl alcohol. The polymerization is performed in two steps; at 80℃ and 200℃ in an ambient atmosphere. The carbonization of the cured body is performed under Nitrogen gas flow (0.8 L/min) at 800℃ for 1 h. Shrinkage rate and residual carbon content are measured by size and weight change after carbonization. The pore structures are observed by both electron and optical microscope and compared with the porosity results achieved by the Archimedes method. The porosity is similar regardless of the size of the phenolic resin particles. On the other hand, the pore size increases in proportion to the phenol resin size, which indicates that the pore structure can be controlled by changing the raw material particle size.

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2004년도 추계총회 및 연구발표회 초록집
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• pp.93.4-93.4
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• 2004

• 한국윤활학회:학술대회논문집
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• 한국윤활학회 1992년도 제15회 학술강연회초록집
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• pp.1-20
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• 1992

1. Ceramics as engineering Materials Ceramic \ulcorner :'material based on inorganic non-metallic compounds' Oxygen, Carbon, Nitrogen with metal (Al, Si) -cheap, plentiful and widespread element in the Earth -dirt: ceramic

• 한국세라믹학회:학술대회논문집
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• 한국세라믹학회 2002년도 추계총회 및 연구발표회 초록집
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• pp.209.2-209
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• 2002

• 한국산학기술학회논문지
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• 제16권8호
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• pp.5728-5735
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• 2015

단일챔버 미생물연료전지에 분리막으로 세라믹막과 나피온막을 적용하여 전기발생특성을 분석함으로써 세라믹막의 적용가능성을 구명하고자 하였다. 또한 환원전극으로서 백금촉매가 도포된 탄소천과 일반 탄소천을 사용하여 백금촉매 효과 및 전기발생특성을 비교하였다. 회분식 실험에서 전기발생특성이 가장 안정적인 것은 acetate를 기질로 사용하였을 때였다. Formate는 전기발생특성이 acetate보다 다소 높았으나 불안정하였고 propionate와 butyrate는 acetate에 비하여 전기발생량이 상대적으로 낮았다. 환원전극으로서 백금촉매가 도포되어 있는 탄소천과 일반 탄소천을 비교한 결과 백금촉매가 도포된 탄소천의 전력발생량이 일반 탄소천에 비하여 1.2배 높게 나타났지만 약 5배 정도 비용 차이가 있음을 고려하면 미생물연료전지의 적용에 있어 효율성과 경제성은 함께 고려되어야 할 것으로 판단된다. 분리막으로서 세라믹막과 나피온막을 적용한 미생물 연료전지에서 발생한 평균 전압은 합성폐수를 이용한 실험에서 각각 $523.67mV{\pm}49.41mV$, $424.09mV{\pm}79.95mV$이었다. 미생물연료전지에 분리막으로 세라믹막과 나피온막을 적용하여 전력발생 및 유기물제거효율을 비교한 결과, 세라믹막이 나피온막의 대안이 될 수 있음을 확인하였다.

• 한국세라믹학회지
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• 제53권1호
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• pp.93-98
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• 2016

Cold plasma and heat treatment were selected as technologies to reduce unburned carbon in fly ash to less than 1.0%. Both cold plasma and heat treatment made it possible to eliminate unburned carbon to less than 1.0%. In the case of fly ash, which almost entirely eliminated unburned carbon with an ignition loss of 0.5%, heat treatment caused adhesion among particles and the BET specific surface area rapidly decreased as the mean particle size increased. On the other hand, with cold plasma, unburned carbon elimination caused the BET specific surface area to decrease and, as no adhesion occurred among particles, the mean particle size became small. Also, cold plasma treatment allowed small spherical particles confined within the unburned carbon particles to be released with the elimination of the unburned carbon frame, so that the quantity of fine particles had a tendency to slightly increase.