• 한국전자현미경학회:학술대회논문집
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• 한국현미경학회 2000년도 제31차 춘계학술대회
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• pp.65-67
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• 2000

• 대한기계학회논문집A
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• 제21권9호
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• pp.1452-1461
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• 1997

The hot press apparatus to obtain the solidified rocks with 60mm of diameter against rock waste was developed, and the optimum conditions for solidification were founded out, of which were 300.deg. C of temperature and 1hr of holding time. The solidified rocks reinforced with the fibers (carbon, steel) were made by means of a hydrothermal hot press method. Fracture toughness of those was obtained using the round compact tension(RCT) specimens. Load and displacement behaviours of the solidified rocks reinforced with the fibers were dependent upon the fiber volume fraction and kind of the fibers. Strength and fracture energy of the solidified rocks with steel were much larger than those of the solidified ones with carbon because of the Bridge's effect, multiple cracking and crack branching phenomena.

• 한국세라믹학회지
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• 제45권11호
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• pp.667-674
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• 2008

In this study, we prepared Fe-activated carbon fiber(ACF)/$TiO_2$ composites with titanium (VI) n-butoxide (TNB) as the titanium source for ACF pre-treated with iron compounds through the impregnation method. In terms of textural surface properties, the composites demonstrate a slight decrease in the BET surface area of the samples and an increase in the amount of iron compounds treated. The surface morphology of the Fe-ACF/$TiO_2$ composites was characterized by means of SEM. The composites have a porous texture with homogenous compositions of Fe and titanium dioxide distributed on the sample surfaces. The phase formation and structural transition of the iron compounds and titanium dioxide were observed in X-ray diffraction patterns of the Fe-ACF/$TiO_2$ composites. The chemical composition of the Fe-ACF/$TiO_2$ composites, which was investigated with EDX shows strong peaks for the C, O, Fe and Ti elements. The photo degradation results confirm that the Fe-ACF/$TiO_2$ composites show excellent removal activity for the COD in piggery waste due to photocatalysis of the supported $TiO_2$, radical reaction by Fe species, and the adsorptivity and absorptivity of ACF.

• 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.

• Composites Research
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• 제36권4호
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• pp.281-287
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• 2023

대량의 폐기물에 의한 환경오염, 세계 평균기온 상승에 의한 기후위기가 인류의 생존을 위협하는 수준에 이르고 있다. 이를 해결하기 위하여 다양한 분야에서 관련 연구가 이루어지고 있으며 재료분야에서도 친환경적이며 탄소중립적인 소재를 개발하기 위한 연구가 활발히 이루어지고 있다. 본 연구에서는 탄소섬유에 천연섬유를 조합함으로써 천연섬유의 장점인 친환경성과 탄소배출 저감을 달성하고자 하였다. 일반적으로 고강도와 저강도 소재를 조합할 경우 그 중간의 물성을 가지는 것으로 알려져 있지만, 본 연구에서는 일부 물성이 탄소섬유 복합재료의 물성을 초과하는 결과를 얻을 수 있었다. 이를 검증하기 위하여 탄소섬유복합재료와 탄소섬유/천연섬유 하이브리드 복합재료를 제조하고 다양한 기계적시험을 통하여 기계적 물성을 비교하고 우수한 물성을 보이는 시험에 대하여 강도향상 기구를 분석하였다. 시험결과 하이브리드 복합재료의 굽힘강도와 파괴인성치가 탄소섬유 복합재료에 비하여 우수하게 나타났으며 강도향상 기구를 규명하였다. 하이브리드 복합재료를 활용할 경우 더욱 우수한 강도의 구조물을 제작할 수 있을 뿐만아니라 환경오염 및 기후위기에도 도움이 될 것으로 예상된다.

• Carbon letters
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• 제7권2호
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• pp.105-113
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• 2006

The electro-chemical removal (ECR) of water pollutants by metal-ACF electrodes from wastewater was investigated over wide range of ECR time. The ECR capacities of metallic ACF electrodes were related to physical properties such as adsorption isotherm, surface area and pore size and to reaction time. Surface morphologies and elemental analysis for the metal supported ACFs after electro-catalytic reaction were investigated by scanning electron microscopy (SEM) and energy disperse X-ray (EDX) to explain the changes in adsorption properties. The IR spectra of metallic ACFs for the investigation of functional groups show that the electro-catalytic treatment is consequently associated with the removal of pollutants with the increasing surface reactivity of the activated carbon fibers. The metal-ACFs were electro-catalytically reacted to waste water to investigate the removal efficiency for the COD, T-N, $NH_4$-N, $NO_3$-N and $NO_2$-N. From these removal results of the piggery waste using metallic ACFs substrate, satisfactory removal performance was achieved. The removal efficiency of the metallic ACFs substrate was mainly determined by the properties of the material for adsorption and trapping of organics, and catalytic effects.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2004년도 학술논문집
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• pp.119-120
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• 2004

A study on the selective adsorption of uranium(VI) from a high concentration of chemical salts has tern peformed to investigate the uranium removal mechanisms and the application conditions of the electrosorption technique using the activated carbon fiber(ACF) as a good conductive electrosorption adsorbent. Electrosorption test were carried out using an electrochemical cell.(omitted)

• 한국항공우주학회지
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• 제40권11호
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• pp.1010-1015
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• 2012

본 연구에서 폐열 에너지를 수집하여 직접 전기로 변환하는 박막형 열전지를 제작하였다. 전도성 탄소섬유에 탄소나노튜브를 코팅함으로써 전기 전도도는 증가하였고, 다양한 곡률 반경에 대한 굽힘 실험에서 전극의 저항변화는 없었다. 열전지의 최대출력은 온도차의 제곱에 비례하여 증가하였으며, $3.4^{\circ}C$의 온도차에서 2.5 mW/kg의 전력을 생산하였다. 12시간의 방전 실험 결과, 열전지는 지속적으로 구동이 가능함을 확인하였다. 또한, 유연한 열전지를 뜨거운 유체가 흐르는 파이프에 감아 구동한 결과, 파이프의 곡률반경에 따라 내부저항은 감소하였고, 생산된 전력은 최대 30 % 상승하였다. 따라서 제작된 열전지는 다양한 곡면형 열원에 적용이 가능하다.

• Carbon letters
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• 제6권1호
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• pp.25-30
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• 2005

The electrosorption of U(VI) from waste water was carried out by using an activated carbon fiber (ACF) felt electrode in a continuous electrosorption cell. In order to enhance the electrosorption capacity at a lower potential, the ACF was electrochemically modified in an acidic and a basic solution. Pore structure and functional groups of the electrochemically modified ACF were examined, and the effects of the modification conditions were studied for the adsorption of U(VI). Specific surface area of all the ACFs was decreased by this modification. The amount of the acidic functional groups decreased with a basic modification, while the amount increased a lot with an acidic modification. The electrosorption capacity of U(VI) decreased on the acid modified electrode due to the shielding effect of the acidic functional groups. The base modified electrode enhanced the capacity due to a reduction of the acidic functional groups. The electrosorption amount of U(VI) on the base modified electrode at .0.3 V corresponds to that of the as-received ACF electrode at .0.9 V. Such a good adsorption capacity was due to a reduction of the shielding effect and an increase of the hydroxyl ions in the electric double layer on the ACF surface by the application of negative potential.

• Nuclear Engineering and Technology
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• 제53권5호
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• pp.1717-1722
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• 2021

This study is devoted to the ability of carbon fiber material samples impregnated with various amounts of barium iodide and triethylenediamine to remove radioactive methyliodide from air streams. The main sorption characteristics of impregnated UVIS® carbon fiber were determined and the use of this material for purifying of technological gas flows at nuclear power plants was evaluated. The methyliodide trapping efficiency by samples impregnated with barium iodide, TEDA, and their mixture was 83.4 ± 0.8%; 93.1 ± 0.6% and 93.5 ± 0.7% respectively, under the same conditions. The study established a significantly higher capacity (8.3 ± 0.07 mg/cm²) of samples impregnated simultaneously with both chemical compounds toward methyliodide. Under the same test conditions, the values of this parameter for the samples impregnated separately with TEDA and BaI₂ were 2.85 ± 0.05 mg/cm² and 0.86 ± 0.04 mg/cm², respectively.