• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2001년도 The 6th International Symposium of East Asian Resources Recycling Technology
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• pp.699-704
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• 2001

Until recently, disposal to landfill has been the most convenient way to deal with the increasing amount of residues the shredding industries produce. But the shortage of such disposal sites and the risk that liquid drained from these waste dusts may pollute ground water have increased the environmental pressures to find more effective solutions. The present study is an alternative approach that suggests identifying waste dusts characteristics and selecting an appropriate binder for hazardous materials to reduce the amount of contaminants (mainly lead) that were leaking into the soil. Investigations on the characteristics of automobiles waste dusts show that these materials are composed mainly of cottons and sponge like substances, plastics, rubber, glasses and gravel, metals, and electric wires. Besides, the percentage in weight of organic (inflammable) materials is about 70% and the lead contamination, which has not a ionic but a particulate nature, is particularly remarkable in cottons and sponge like materials. Binding additives such as K-20 and sodium carbonate were not effective but the addition of 5 % of cement (in weight of the investigated sample) followed by a 3-minute stirring and a 4-hour storage could drastically reduce the run off of lead below the maximum authorized level. No addition of water was necessary in this method.

• 한국수소및신에너지학회논문집
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• 제24권5호
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• pp.421-427
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• 2013

We report on the time dependent degradation of cell in dye-sensitized solar cells (DSSC). The photovoltaic performance of DSSC over a period of time was investigated in liquid electrolyte based on triiodide/iodide during six days. It was found that the short circuit current density ($j_{sc}$) of the cell dropped from 9.9 to $7mA/cm^2$ while efficiency (${\eta}$) of the cell decreased from 4.4 to 3.3%. The parameters corresponding to fundamental electronic and ionic processes in a working DSSC are determined from the electrochemical impedance spectrascopy (EIS) at open-circuit potential ($V_{oc}$). EIS study of the DSSC in the this work showed that the electron life time ${\tau}_r$ and chemical capacitance $C_{\mu}$ decreased significantly after six days. It was correlated the $j_{sc}$ and efficiency decreased after six days.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.442-442
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• 2014

Although electrochemical capacitors (ECs), also known as supercapacitors or ultracapacitors, is one of the most promising energy-storage devices because of its high power density, super-high cycle life, and safe operation. We herein report a synthesis of graphene-based flexible films by kneading method. Thus, a device can be readily made by sandwiching a polymer membrane included ionic liquid electrolytes between two identical graphene-based flexible films. Devices made with these electrodes exhibit ultrahigh energy density values while maintaining the high power density and excellent cycle stability of ECs. Moreover, these ECs maintain excellent electrochemical attributes under high mechanical stress and thus hold promise for high-energy, flexible electronics.

• Biotechnology and Bioprocess Engineering:BBE
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• 제2권2호
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• pp.117-121
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• 1997

Glutamic acid can be crystallized inside cation exchange column when displacer NaOH concentration is high enough to concentrate displaced glutamic acid beyond its solubility limit. Resulting crystal layer of glutamic acid was moved with liquid phase through the column, and thus could be eluted from the column and recovered in fraction collector. For the purpose of enhancing crystal recovery, effects of operating parameters on the crystal formation were investigated. The increase in the degree of crosslinking of resin favored crystal recovery because of its low degree of swelling. Higher concentration of displacer NaOH was advantageous. If NaOH concentration is too high, however, crystal recovery was lowered due to the solubility-enhancing effects of high pH and ionic strength. The decrease of mobile phase flow rate enhanced crystal recovery because enough time to attain local equilibrium could be provided, but film diffusion would control the overall crystal formation with extremely low flow rate. Lower temperature reduced solubility of glutamic acid and thus favored crystal formation unless the rate of ion exchange was severely reduced. The ion exchange operated by displacement mode coupled with crystallization was advantageous in reducing the burden of further purification steps and in preventing purity-loss resulted from overlapping between adjacent bands.

• 한국방사성폐기물학회:학술대회논문집
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• 한국방사성폐기물학회 2003년도 가을 학술논문집
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• pp.650-654
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• 2003

원자력분야에서 방사성폐기물 처리 및 처분은 해결해야 할 중요한 문제가 된다. 보다 청정한 방법을 사용한 제염법이 요구되고 있다. 이산화탄소를 이용한 제염법은 두가지로 나눠지는데-킬레이트제를 이용한 방법과 에멀젼을 이용한 방법이다. 킬레이트제 방법은 시너지효과를 낼 수 있는 방안이 중요하다. 마이크로 에멀젼을 사용한 방법은 에멀젼 코어속에 산을 넣어 금속표면이나 토양에서 오염물질을 직접 꺼내는 방법이다. 표면제거율을 QCM을 사용하여 측정하였다. 에멀젼을 만드는데 사용된 계면활성제의 회수 방법에 대하여 아울러 논의하였다.

• 멤브레인
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• 제26권3호
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• pp.173-178
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• 2016

본 총설에서는 고분자와 은염으로 구성된 고분자 전해질 분리막과 장시간 안정성을 해결하기 위한 방안들이 정리되었다. 특히 이온성 액체를 활용하여 $AgNO_3$를 새로운 운반체로 사용하기 위한 방안, 새로운 고분자 매트릭스로서 poly(ethylene phthalate) (PEP)를 활용하는 방안과 가장 최근 알루미늄 염을 활용하여 운반체의 안정성을 부여하는 연구결과들이 정리되었다. 올레핀 촉진수송을 위한 고분자 나노복합체 분리막의 경우, 운반체인 은 나노입자 표면을 극성화시킬 수 있는 전자수용체의 종류와 특징들이 소개되었으며, 최근 투과도 성능을 향상시킬 수 있는 연구결과들이 정리되었다.

• 한국세라믹학회지
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• 제53권6호
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• pp.635-640
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• 2016

Electrical behavior of AlN ceramics sintered with $Y_2O_3$ as a sintering aid has been investigated with respect to additional $TiO_2$ dopant. From the impedance spectroscopy, it was found that the grain and grain boundary conductivities have greatly decreased with addition of $TiO_2$ dopant. The $TiO_2$ dopant also increased the activation energy of the grain conductivity by about 0.37 eV; this increase was attributed to the formation of an associate between Al vacancies and Ti ions at the Al sites. Similarly, the electronic conductivity was reduced by $TiO_2$ addition. However, $TiO_2$ solubility in AlN grains was below the detection limit of typical EDX analysis. Grain boundary was clean, without liquid films, but did show yttrium segregation. The transference number of ions was close to 1, showing that AlN is a predominantly ionic conductor. Based on the observed results, the implications of using AlN applications as insulators have been discussed.

• KSBB Journal
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• 제8권4호
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• pp.370-374
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• 1993

Crown ether류인 dibenzo-18-crown-건를 carn­e er로 이용하여 액체막을 통해서의 금속이온의 이동 량을 picric acid의 absorbance를 ultraviolet spec trometer로 측정하여 평가하였다. 그 결과 dibenzo 18-crown-6에 의한 금속이온의 이동은 2가 금속이 온이 l가 금속이온 보다도 더 컷다. 이것은 이 계에 서는 이들 금속이온의 크기보다도 이온의 전하와 수 화(hydration)의 영향을 받았다. 이것은 18-crown-6가 $Ca^{2+}$이온과 같은 2가 이온의 수송에 적합하다 는 것을 의미한다. 또한 dibenzo-18-cro뻐-6에 의 한 이온의 수송은 이온의 선택성을 갖지 않고 이온을 포착할 수 있는 능력을 갖는 것이 좋은 것으로 확인되였다.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4093-4097
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• 2012

We introduced a new UV-cured resin polymer gel as an electrolyte for dye-sensitized solar cells (DSSCs) that is cured with UV irradiation to form a thin film of UV-cured resin polymer gel in the cells. The gel film was characterized and its potential for use as an electrolyte in DSSCs was investigated. This new UV-cured resin polymer gel was successfully applied as a gel polymer electrolyte in DSSCs overcoming the problems associated with the liquid electrolytes in typical DSSCs. The effect of ${\gamma}$-butylrolactone (GBL) on the long-term stability and photovoltaic performance in DSSCs using this UV-cured resin polymer gel electrolyte was also investigated. The results of the energy conversion efficiency, ionic conductivity and Raman spectra of the UV-cured resin polymer gel electrolyte with the addition of 6 wt % GBL to the UV-cured resin polymer electrolyte showed good long-term stability and photovoltaic performance for the DSSCs with the UV-cured polymer gel electrolyte.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2017년도 제48회 춘계학술대회논문집
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• pp.1061-1067
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• 2017

1960년대 이후부터 하이드라진($N_2H_4$)은 로켓, 인공위성 또는 심우주 임무용 추진제로 사용되어 왔다. 하지만 하이드라진의 높은 독성과 운영비용으로 이온성 액체 추진제(ADM, HAN) 및 아산화질소 연료 혼합물(NOFB)과 같은 친환경 추진제에 대한 요구가 증가하고 있다. 아산화질소 연료 혼합물(NOFB)은 이원추진제가 갖는 높은 성능과 단일추진제의 단순한 공급시스템 장점을 모두 갖는 추진제로서, 적절한 취급방법과 설계가 적용된다면 전통적인 하이드라진 추진 시스템을 대체할 만한 추진제로 사용가능할 것이다.