• 한국세라믹학회지
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• 제36권6호
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• pp.577-582
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• 1999

Activated carbon fibers were prepared from stabilized PAN fibers by chemical activation using hydroxide. The variations in specific surface area amount of iodine adsorption micro-structure and pore size distribution in the activated carbon fibers after the activation process were discussed. In the chemical activation using potassium hydroxide specific surface area of about 2545m2/g and amount of iodine adsorption of 2049 mg/g were obtained at the condition of KOH/fiber ratio of 1 and 800$^{\circ}C$ Nitrogen adsorption isotherms for PAN based activated carbon fibers showed the type I in the Brunauer-Deming-Deming-Teller classification indicating the micro-pores consisting the activated fibers.

• Journal of Forest and Environmental Science
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• 제23권1호
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• pp.51-55
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• 2007

본 연구는 염화아연을 이용한 화학약품 부활법으로 잣나무재 활성탄을 제조하기 위해 원료에 대한 화학약품부활제 비율의 영향을 검토하였다. 염화아연과 혼합한 목분은 질소분위기에서 상온에서 $600^{\circ}C$까지 1시간 열처리하여 중량변화를 측정하였다. 이 처리과정에 있어 활성탄 내부에 다양한 공극크기 분포와 표면특성이 확인되었다. 즉, 최대 BET 표면적과 총 공극체적은 목분에 대하여 염화아연의 비율이 5배인 경우였으며, 각각 그 값은 $1468m^2/g$와 1.74 cc/g이었다. 결론적으로 활성탄 제조시 화학약품부활제의 비율에 의해 활성탄의 특성이 뚜렷하게 차이가 나타나는 것이 확인되었다.

• International Journal of Concrete Structures and Materials
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• 제8권4호
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• pp.289-299
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• 2014

Alkali-activated slag concretes are being extensively researched because of its potential sustainability-related benefits. For such concretes to be implemented in large scale concrete applications such as infrastructural and building elements, it is essential to understand its early and long-term performance characteristics vis-a'-vis conventional ordinary portland cement (OPC) based concretes. This paper presents a comprehensive study of the property and performance features including early-age isothermal calorimetric response, compressive strength development with time, microstructural features such as the pore volume and representative pore size, and accelerated chloride transport resistance of OPC and alkali-activated binder systems. Slag mixtures activated using sodium silicate solution ($SiO_2$-to-$Na_2O$ ratio or $M_s$ of 1-2) to provide a total alkalinity of 0.05 ($Na_2O$-to-binder ratio) are compared with OPC mixtures with and without partial cement replacement with Class F fly ash (20 % by mass) or silica fume (6 % by mass). Major similarities are noted between these binder systems for: (1) calorimetric response with respect to the presence of features even though the locations and peaks vary based on $M_s$, (2) compressive strength and its development, (3) total porosity and pore size, and (4) rapid chloride permeability and non-steady state migration coefficients. Moreover, electrical impedance based circuit models are used to bring out the microstructural features (resistance of the connected pores, and capacitances of the solid phase and pore-solid interface) that are similar in conventional OPC and alkali-activated slag concretes. This study thus demonstrates that performance-equivalent alkali-activated slag systems that are more sustainable from energy and environmental standpoints can be proportioned.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2020년도 봄 학술논문 발표대회
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• pp.138-139
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• 2020

With the rapid progress of industrialization, indoor air quality is a very important factor for modern people who spend most of their day indoors. The recent issue of fine dust and radon on the portal site's popularity search shows that interest in indoor air quality has increased. Fine dust causes respiratory diseases, and radon causes severe lung cancer. The new material was tested using plant activated carbon, palm activated carbon and bamboo activated carbon. Both palm activated carbon and bamboo activated carbon are porous materials and generate smooth physical adsorption. As a result of the experiment, both the activated carbon tends to gradually decrease in strength and fluidity as the replacement ratio increases. The reason for this is that both activated carbons have the property of absorbing moisture, so it is judged that the strength is lowered by absorbing moisture necessary for curing. In the case of fluidity, it is judged that the fluidity is reduced by absorbing the moisture required for the flow. In the future, if the problem of the color of the finished cured body is compensated, it will be possible to manufacture a functional finishing board to replace the existing interior finishing material.

• 콘크리트학회논문집
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• 제25권3호
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• pp.305-312
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• 2013

이 연구는 물-결합재(W/B) 비에 따른 실리카 퓸이 알칼리 활성화 슬래그 시멘트(AASC)에 미치는 유동성과 강도 특성에 대한 연구이다. W/B비는 0.50에서 0.60까지 0.05 단위로 일정하게 변화시켰다. 실리카 퓸은 고로슬래그 중량의 0%에서 50%까지 치환시켰다. 활성화제는 수산화나트륨(NaOH)를 사용하였고, 농도는 3M로 하였다. W/B 비에 따른 강도는 1, 3, 7 그리고 28일을 측정하였다. 유동성 측정 결과는 실리카 퓸의 치환율이 증가할수록 감소하였다. 압축강도는 실리카 퓸의 치환율이 증가할수록 증가하였다. 또한 W/B 비가 증가할수록 모든 재령에서 강도는 감소하였다. 실리카 퓸은 W/B 비와 실리카 퓸의 치환율에 따라서 활성화 반응을 증대시켜 강도를 증가시키는 것을 알 수 있었다.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2010년도 춘계학술대회 초록집
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• pp.133.1-133.1
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• 2010

In this work, carbon black(CBs)-embed multi-walled carbon nanotubes (MWNTs) as conductive fillers for activated carbon(ACs)-based electrodes for supercapacitor were prepared by chemical reduction of oxidized MWNTs and CBs. The effect of CBs-MWNT composites on electrochemical performances of ACs-based electrodes were investigated as a function of CB-MWNT ratio. It was found that CBs-MWNTs composites were formed by the reduction reaction of the functional groups of oxidized MWNTs and CBs. It was resulted in the conjugation of CBs onto the MWNT having high surface area and aspect ratio, leading to the enhanced electrical properties of MWNTs. The electrochemical performances, such as current density, charge-discharge, and specific capacitance of the ACs/CBs-MWNT electrodes were higher than that of ACs/MWNTs and conventional ACs/CB electrodes, which was attributed to the synergistic effect of CBs-MWNTs as a conductive filler.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2009년도 추계학술대회 논문집
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• pp.627-627
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• 2009

In this work, the activated carbons (ACs) with high porosity were synthesized from pitch by KOH chemical activation. The structure and surface properties of ACs were characterized by means of elemental analysis, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy(XPS). And, the influence of the KOH-to-pitch ratio on the porosity of the ACs was investigated using the nitrogen adsorption isotherms at 77 K and a scanning electron microscopy (SEM). As a result, pitch could be successfully converted into ACs with well-developed micro and mesopores. The specific surface areas and pore volumes were increased with an increase of the KOH-to-pitch ratio. Furthermore, it was found that the addition of KOH led to the transformation of the micropores to the meso- and macropores. In the application to electric double layer capacitors (EDLC), the pitch-based ACs showed a higher capacitance per weight and per volume, and an excellent electrochemical stability in the high voltage region.

• 한국대기환경학회지
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• 제15권2호
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• pp.183-190
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• 1999

Magnetite was synthesized with $FeSO_4$, and NaOH for the decomposition of carbon dioxide and for the study of the methane formation. The chemical equivalent ratio was changed from 0.5 to 1.50 for the magnetite synthesis. The chemical equivalent ratio was fixed in 1.00, and Nickel chloride and Rhodium chloride equally added and synthesized with the ratio was of 0.10~10.00 mole%. The crystal strucure of the synthesized magnetite was measured XRD. Putting synthesized magnetite in the reactor and using hydrogen gas oxygen-deficient magnetite was made. Injecting carbon dioxide in the reactor, the decomposition reaction was experimented. The formation of methane was confirmed injecting hydrogen gas in the reactor after carbon dioxide was decomposed.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.205-206
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• 2016

This study examines the effect of binding material and alkali activator on the rheology characteristics of alkali active mortar quantitatively, and a result is as follows. In the 1/2 slump flow, the higher mixing ratio of the fly ash has been shown to increase the table flow. the reason is that fly ash ball bearing action. When viewed in the consistency curve, the higher mixing ratio of the blast furnace slag powder was higher shear stress.

• 한국응용과학기술학회지
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• 제19권3호
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• pp.213-221
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• 2002

Activated carbons with high surface area of 2,600 $m^{2}/g$ and high pore volume of 1.2 cc/g could be prepared by KOH activation of rice hulls at a KOH:char ratio of 4:1 and $850^{\circ}C$. In order to increase the adsorption capacity of hydrogen sulfide, which is one of the major malodorous component in the waste water treatment process, various contents of $Na_{2}CO_{3}$ and $KIO_{3}$ were impregnated to the rice-hull activated carbon. The impregnated activated carbon with 5 wt.% of $Na_{2}CO_{3}$ showed improved $H_{2}S$ adsorption capacity of 75 mg/g which is twice of that for the activated carbon without impregnation and the impregnated activated carbon with 2.4 wt.% of $KIO_{3}$ showed even higher $H_{2}S$ adsorption capacity of 97 mg/g. The improvement of $H_{2}S$ adsorption capacity by the introduction of those chemicals could be due to the $H_{2}S$ oxidation and chemical reaction with impregnated materials in addition to the physical adsorption of activated carbon.