• 전기학회논문지
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• 제61권4호
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• pp.595-600
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• 2012

In this paper, it is investigated the characteristics of DSSC(Dye Sensitized Solar Cell) with cell area(0.25, 1, 2.25 $cm^2$) and dye absorption time(12, 24, 36 h). Thus, we obtain the following results by using the EIS, UV-VIS, I-V measurement. When the cell area increases, the efficiency decreases to 21~32 percent because of the increase about 40~$60{\Omega}$ of internal impedance regardless of dye absorption time. When the absorption time increases up to 24 hours, the efficiency increases to over 40 percent cause of the reduction of internal impedance regardless of cell area. When the dye absorption time becomes 36 hours, the internal impedance increases and at the same time, in the range of 600~700 nm, as the optical absorption reduces. Therefore, the efficiency decreases to 19~31 percent. When it is absorbed the dye for 24 hours in the smallest cell area which is 0.25 $cm^2$, the DSSC has the best efficiency (7.11 %).

• 한국환경과학회지
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• 제23권5호
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• pp.943-962
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• 2014

Industrial gas drying, dilute gas mixtures purification, air fractionation, hydrogen production from steam reformers and petroleum refinery off-gases, etc are conducted by using adsorptive separation technology. The pressure swing adsorption (PSA) has certain advantages over the other methods, such as absorption and membrane, that are a low energy requirement and cost-effectiveness. A key component of PSA systems is adsorbents that should be highly selective to a gas being separated from its mixture streams and have isotherms suitable for the operation principle. The six standard types of isotherms have been examined in this review, and among them the best behavior in the adsorption of $CO_2$ as a function of pressure was proposed in aspects of maximizing a working capacity upon excursion between adsorption and desorption cycles. Zeolites and molecular sieves are historically typical adsorbents for such PSA applications in gas and related industries, and their physicochemical features, e.g., framework, channel structure, pore size, Si-to-Al ratio (SAR), and specific surface area, are strongly associated with the extent of $CO_2$ adsorption at given conditions and those points have been extensively described with literature data. A great body of data of $CO_2$ adsorption on the nanoporous zeolitic materials have been collected according to pressure ranges adsorbed, and these isotherms have been discussed to get an insight into a better $CO_2$ adsorbent for PSA processes.

• 대한환경공학회지
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• 제39권2호
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• pp.66-73
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• 2017

본 연구에서는 제올라이트 X를 이용한 Cs 이온 흡착시 흡착시간 및 초기농도, 온도 및 pH 변화와 같은 영향인자를 평가하였다. 이 결과로부터 Cs 이온의 흡착속도, 등온흡착량 및 열역학적 특성을 해석하였다. 제올라이트 X에 의한 Cs 이온의 흡착은 pH 5~10에서 효과적이었으며, 평형흡착시간은 약 60분이었다. 흡착속도와 등온흡착량은 유사 2차 속도 모델식과 Langmuir 식에 잘 적용되었다. Langmuir 식으로 구한 Cs 이온의 최대 흡착량은 293~333 K에서 각각 303.03~333.33 mg/g이었다. 제올라이트 X에 의한 Cs 이온의 흡착은 흡열반응이고 자발적인 반응이었다. 실험값을 다중회귀분석으로 최적화하여 2차 다항식을 얻었다. 이 최적화된 식으로부터 구한 종속변수의 값과 실험에서 구한 값은 잘 일치하였다.

• 한국환경과학회지
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• 제15권6호
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• pp.579-586
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• 2006

The purposes of this paper were to monitor the temperature rising courses and spark discharge of the modified granular activated carbon (GAC) by microwave (MW) irradiation and to evaluate absorption of benzene. The GAC coated on $SiO_2$, boron, talc, ferrite was named as the modified GAC. Thermal and spark discharge measurement of virgin GAC and modifed GAC has been carried out using a MW device operating at 2450 MHz under various energy conditions. The results of this paper as follows. First, the modified GAC is more efficient than the virgin GAC in temperature control. Temperature gradient of the modified GAC is more lower than that of virgin GAC. The temperature gradient of GAC was observed in the following order : virgin GAC, Mn-Zn ferrite/GAC, Ni-Zn ferrite,/GAC, $SiO_2/GAC$, Boron/GAC, Talc/GAC. Second, the spark discharge of the modified GAC was diminished, compared with that of virgin GAC. Because of its excellent electrical insulating properties, the coating material prevents the spark discharge. Finally, the benzene adsorption capacity of the modified GAC decreased due to diminishing of adsorption site by the coating material. Considering the temperature gradient and spark discharge of GAC, the GAC coated $SiO_2$ would be appropriate absorbent under irradiation of MW.

• 한국지반공학회논문집
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• 제16권2호
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• pp.91-102
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• 2000

자연점토지반에서의 중금속 흡착시 온도변화에 따른 영향은 지금까지 2차적인 것으로 간주되었다. 그러나 최근 몇몇 연구자들에 의하면 온도변화가 중금속 흡착 거동에 큰 영향을 미친다고 보고하였다. 따라서 본 연구에서는 자연점토 지반에 대한 중금속 아연(Zn) 흡착시 온도변화에 따른 흙의 각 구성성분별 흡착거동을 살펴보기 위해 혼합 흡착-연속추출법(combined absorption-sequential extraction analysis, CASA)을 사용하였다. 실험결과 중금속 아연의 농도가 저농도(50mg/L 미만)일 경우 자연지반에서의 분배양상은 주로 탄산염 형태로 존재하고, 또한 온도의 증가에 따라 탄산염 형태의 흡착량이 증가하는 것을 알 수 있다. 하지만 고농도(50mg/L 이상)의 경우 분배양상은 주로 이온교환형태로 존재한다는 것을 알 수 있다. 그러나 고농도에서의 이러한 분배형태는 온도의 증가에 따라 탄산염형태의 흡착량이 약 20%정도 증가하는 결과를 얻었다. 결론적으로 중금속 아연의 자연점토지반의 각 구성성분 별 흡착거동은 이온교환 형태를 제외하고 온도증가에 따라 증가하는 흡열반응(ΔH0>0)인 것으로 나타났고, 또한 고농도에서의 분배형태는 이온교환 형태에서 탄산염 형태로 변화되는 것을 알 수 있다. 그리고 이온교환 형태의 경우 온도변화에 따라 독립적인 거동을 보였다.

• 한국염색가공학회지
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• 제12권3호
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• pp.192-198
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• 2000

Influence of the fluorescent whitening agent(FWA)'s adsorption on the whiteness of cotton and on the color change of the dyed fabrics was investigated by repeating wash cycles. Cotton 100% and cotton60/polyester40 blended fabrics were dyed pink, blue and yellow, and cyanuric chloride diamino stilbene(CC/DAS) and distyryl bisphenyl(DSBP) were used for the FWA with laundry detergents. Fabrics were washed at $20^\circ{C}$ with Terg-o-tometer. The FWA adsorption amount was measured by the absorption intensity for the pyridine-water extracted solution. The FWA adsorption increased on the cotton fabric with the wash cycles. Though adsorption of CC/DAS continuously increased up to the 20th cycle, that of DSBP increased sharply before the 10th cycle and reached an equilibrium. The whiteness of the fabrics dried in the shade was greater than that dried under the sunlight through window glass. The color change of dyed fabrics was increased by the number of wash cycles. Pink changed more greatly than blue, yellow or grey cloth. The color change(\Delta{E)}$ of dyed fabric washed repeatedly up to the 20th cycle with the detergent without FWA was less than 1. It is recommended to wash pale colored fabric with the detergent free of FWA.

• Journal of the Korean Wood Science and Technology
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• 제31권6호
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• pp.83-88
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• 2003

The woodceramics are porous amorphous carbon and glassy carbon composite materials. Woodceramics attracted a lot of attention in recent years because they are environmentally friendly and because of their unique functional characteristics such as catalysis, moisture absorption, deodorization, purification, carrier for microbial activity, specific stiffness, corrosion and friction resistance, and their electromagnetic shielding capacity. In this paper, we made new products of clay-woodceramics to investigate the industrial analysis and ethylene gas adsorption for basic data of building- and packging- materials keeping fruit fresh for a long time. Clay-woodceramics were carbonized for 3 h of heating in a special furnace under a gas flow of nitrogen(15 ml/min.) from 3 layers-clay-woodparticleboard made from pallet waste wood, phenol- formaldehyde resin(hereafter PF, Non volatile content:52%, resin content 30%), and clay(10%, 20% and 30%). Carbonization temperature was 400℃, 600℃ and 800℃. Experimental results shows that the higher the carbonization temperature, the higher the fixed carbon and the lower the volatile contents. The higher the clay content, the more the ash content. The higher the carbonization temperature, the more the ethylene gas adsorption. Carbonization temperature of 800℃ gave the best reslts as same as that of white charcoal and activated carbon.(800℃-clay-woodceramic: 5.36 ppm, white charcoal: 5.66 ppm, activated carbon: 5.79 ppm) The clay contents did not make difference of ethylene gas adsoption.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.146-147
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• 2021

An increase in carbon emissions leads to the problem of global warming and is an issue to be solved in other countries. The problem of carbon dioxide has many effects not only on global warming but also on people. According to the World Health Organization (WHO), 4.3 million people have died because harmful substances generated indoors cannot be discharged to the outside and accumulate in the human body through the respiratory tract. In response to this situation, in order to reduce the generation of pollutants in the building itself, soak into lightweight bubble concrete to adsorb and purify indoor pollutants, mix charcoal, investigate the appropriate amount and physical characteristics, and check carbon dioxide This is an experiment for grasping the adsorption capacity, and the results are as follows. As the replacement rate of rice husk charcoal increased, the compressive strength tended to decrease, and the carbon dioxide reduction rate tended to increase. It is judged that the charcoal of rice husks shows a low density and the physical adsorption is smooth due to the porous structure. Since it is excellent in the basic physical properties and carbon dioxide adsorption surface of this experiment, it is judged that it has sufficient potential for use as an indoor finishing material.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 가을학술발표대회논문집
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• pp.71-72
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• 2023

As industrialization and urbanization accelerate, environmental issues have moved from local concerns to global issues. Among them, air pollution is the most important issue. Modern people spend more than 88% of their day indoors, but the concentration of fine dust and pollutants flowing indoors is increasing. The indoor environment has its own complexity, and various substances used indoors, such as building materials, furniture, electronics, and cleaning agents, emit chemical substances and cause various diseases. Therefore, when selecting building materials and interior finishing materials, the pollutant emission and adsorption capacity must be greatly considered. These considerations will ensure the construction of a sustainable future environment and a healthy life within that environment. Therefore, in order to reduce the generation of indoor air pollutants, this study aims to examine the fine dust adsorption properties of cement hardening materials using sepiolite, which has a porous structure and high absorption power among clay minerals. As a result of the experiment, it was found that the concentration of fine dust decreased as the addition rate of sepiolite increased. It is believed that the fine dust concentration was reduced due to the high porosity due to the microfibrous structure and large specific surface area of sepiolite, which has a porous structure among clay minerals. It is believed that these experimental results can be used as basic research for future use of sepiolite as a construction material.

• 한국지하수토양환경학회지:지하수토양환경
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• 제14권1호
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• pp.29-35
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• 2009

본 연구에서는 석탄광산 배수(CMD)를 전기정화법으로 처리 시 발생되는 슬러지를 흡착제로 금속광산 산성배수(AMD)중 중금속 처리 시 pH와 온도변화에 따른 중금속 흡착 거동을 연구하고자 하였다. 실험결과 CMDS의 pH$_{zero\;point\; charge}$:(pH$_{zpc}$)는 5로 나타났다. pH영향의 경우 구리, 아연, 카드뮴, 철은 pH 증가에 따라 제거율은 증가하였고, 구리의 경우 흡착량은 pH와 상관없이 0.64 mg g$^{-1}$ sludge로 나타났다. pH 5 이상일 때 기타 중금속 흡착량은 pH3일 때의 1.1 배로 나타났고 크롬의 경우 pH 7 이상에서 다소 증가하였는데 이는 크롬이 $Cr(OH)_{6}^{3-}$형태로 미량 용출되었기 때문이다. 온도의 영향에서 pH3일때 온도증가에 따라 중금속 흡착량은 증가하였고, 선택도Cd>Fe>Zn>Cu순으로 나타났다. pH 5이상에서 최대 흡착량(q$_{max}$)은 Cu와 Zn의 경우 각각 2.747mg g$^{-1}$와 2.525mg g$^{-1}$로 더 이상의 흡착이 일어나지 않아 온도의 영향을 받지 않은 것으로 판단된다.