• 한국환경과학회지
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• 제27권7호
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• pp.489-497
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• 2018

In this study, the ion index characteristics of small and medium urban land use types were investigated in the city of Chungju. The average temperature for each land use type was in the order: general commercial district ($29.59^{\circ}C$) > general residential district ($28.34^{\circ}C$) > productive green district ($28.31^{\circ}C$). The average relative humidity was in the order: productive green district (70.12%) > general residential district (69.93%) > general commercial district (66.48%). The average wind speed was in the order: productive green district (0.95 m/s) > general commercial district (0.87 m/s) > general residential district (0.54 m/s). Positive and negative ions were investigated to determine the ion index by land use type. The average amount of positive ion generated was in the order: general commercial district ($737ea/cm^3$) > general residential district ($492ea/cm^3$) > productive green district ($445ea/cm^3$). The average negative ion production decreased in the order: productive green district ($930ea/cm^3$) > general residential district ($754ea/cm^3$) > general commercial district ($744ea/cm^3$). The ion index calculated from measured data can be arranged in the order: productive green district (2.09) > general residential district (1.53) > general commercial district (1.01). These results confirm the state of positive and negative ion generation in each land use type. Further, the differences in the ion index by land use type were confirmed. However, a limitation of this study is that simple summer measurements were conducted, and seasonal characteristics were not considered. Therefore, any future investigation and research should consider seasonal variation characteristics.

• 멤브레인
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• 제30권4호
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• pp.276-281
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• 2020

알칼리 금속 이온과 염소 이온이 포함된 용액으로부터 이온교환수지를 이용한 이온 제거에 대한 연구를 진행하였다. 양이온인 금속이온(Na⁺와 K⁺)의 제거에는 양이온교환수지를, 음이온인 염소 이온(Cl^-)의 제거에는 음이온교환수지를 사용하였다. 용액 A (Na⁺를 36,633 ppm, Cl^-를 57,921 ppm 함유)의 경우, Na⁺ 이온과 Cl^- 이온은 20분 이내에 99% 이상 제거되었다. 용액 B (K⁺를 1,638 ppm 함유)의 경우, K⁺ 이온은 3분 이내에 99% 이상 제거되었다.

• 한국세라믹학회지
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• 제47권6호
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• pp.613-617
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• 2010

Ferro-Nickel slag is one of the by-products in Ferro-Nickel manufacturing process. The slag is composed of $SiO_2$, MgO, $Fe_2O_3$ and others. But the slag has been buried at landfill despite having valuable elements. This study tried to extract Mg ion and fabricate Mg compound from ferro-nickel slag using hydrochloric acid solution. Mg ion was extracted with Si, Fe and other ions in HCl solution. So reprocess was needed for gaining high purity Mg ion. It was thought that Si ion or $SiO_2$ precipitated in HCl solution and removed from solution in filtering process. Fe ion converted into $Fe(OH)_3$ after reacted with $NH_4OH$ and precipitated in HCl solution. After these process, the filtrate was composed of high purity Mg ion. $MgCl_2{\cdot}NH_4Cl{\cdot}6H_2O$ was obtained through drying of filtrate and this product was changed into MgO by burning process ($600^{\circ}C$-30 min). That is, 1st material or solution for manufacturing 2nd product was fabricated using acid dissolution method and other treatments.

• 한국환경성돌연변이발암원학회지
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• 제25권2호
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• pp.71-75
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• 2005

Green tea and their major constituents such as catechins are famous materials for their anti-oxidative and anti-carcinogenic activity, but many compounds with reducing power can promote the oxidation in their oxidized form or in the presence of metal ion. We investigated the pro-oxidative effect of the ethanol extract equivalent up to 30mg of dried weight of green tea leaves in four in vitro systems which could be used for detecting DNA damage. Although ethanol extract of green tea did not show significant mutagenicity in Salmonella typhimurium TA102, which is sensitive strain to oxidative stress, it degraded deoxyribose extensively in the presence of $FeCl_3-EDTA$ complex, promoted 8-oxoguanine formation in the live bacteria cell, Salmonella typhimurium TAI04, and cleaved super coiled DNA strand with the help of copper ion. It suggested that green tea, famous anti-oxidative material, can be pro-oxidant according to the condition of extraction or metal existence.

• 한국환경생태학회지
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• 제33권3호
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• pp.354-365
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• 2019

본 연구에서는 충청북도 충주시를 대상으로 폭염시 토지이용유형별 보행공간의 기상특성과 공기이온 특성을 측정 및 분석하였다. 연구대상지 보행공간의 토지이용유형 구분은 지적편집도를 이용하여 대상지를 크게 Green Area, Residential Area, Commercial Area으로 실시하였다. 측정지점은 약 4.1km, 44개 지점으로 측정지점을 선정하여 외곽지역 관통도로 보행공간 Green Area 12개 지점, Residential Area 14개 지점, Commercial Area 18개 지점으로 구분하여 측정하였다. 또한 폭염시 토지이용유형별 보행공간의 기온, 상대습도, 일사량, 순복사량 등의 기상요소가 음이온 발생량, 양이온 발생량에 미치는 영향을 분석하여 이온지수를 산출하였다. 폭염시 토지이용유형별 보행공간의 공기이온 특성 비교결과 평균 양이온 발생량은 Commercial Area($700.73ea/cm^3$) > Residential Area($600.76ea/cm^3$) > Green Area($589.73ea/cm^3$)로 분석되었다. 평균 음이온 발생량은 Green Area($663.95ea/cm^3$) > Residential Area($628.48ea/cm^3$) > Commercial Area($527.48ea/cm^3$)로 분석되었다. 평균 이온지수는 Green Area(1.13) > Residential Area(1.04) > Commercial Area(0.75)로 분석되었다. 본 연구는 폭염시 토지이용유형별 보행공간에 따른 기상특성, 양이온 발생량과 음이온 발생량 현황을 확인할 수 있었으며, 토지이용유형별 보행공간의 이온지수의 차이를 확인할 수 있었다. 그러나 이동측정에 따른 토지이용유형별 정확한 비교 부족과 도로 폭 변화에 대한 정량적 특성 비교가 부족한 한계점이 존재하였다. 따라서 도로 특성을 고려한 지속적인 연구가 이루어져야할 것으로 판단되었다.

• 멤브레인
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• 제27권5호
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• pp.406-414
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• 2017

본 연구에서는 얇은 폴리에틸렌 계 다공성 필름(두께 = $25{\mu}m$)에 이오노머를 충진시킨 세공충진 이온교환막을 개발하였으며 이를 적용한 전 바나듐 레독스 흐름전지의 충방전 특성을 고찰하였다. 특히 분자 크기가 다른 가교제를 혼합함으로써 이온교환막의 가교도 및 자유체적을 적절히 제어하여 저저항 및 저 바나듐 투과도를 나타내는 이온교환막을 제조하고자 하였다. 실험 결과, 제조된 세공충진 이온교환막은 상용막 대비하여 동등 수준의 우수한 전기화학적 특성을 나타내었다. 또한 바나듐 이온 투과도 및 전 바나듐 레독스 흐름전지 성능 평가 실험을 통해 얇은 막 두께에도 불구하고 상용막 대비하여 낮은 바나듐 이온 투과도와 높은 충방전 효율을 나타냄을 확인하였다.

• 멤브레인
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• 제29권5호
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• pp.237-245
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• 2019

암모니아성 질소($NH_4-N$)는 산업 폐수, 농업 및 축산 폐수에 포함되어 있으며 인과 함께 수질의 부영양화를 일으키는 물질로 잘 알려져 있다. 또한 망간(Mn)과 비소(As)는 광산 처리수 등에 포함되어 있으며, 수질 오염의 원인 물질로 알려져 있다. 천연 제올라이트는 수중에서 암모니아성 질소를 제거하는데 사용되고 있지만 낮은 흡착능력을 가진다. 이러한 천연 제올라이트의 낮은 흡착능력을 개선하기 위해 $Na^+$, $Ca^{2+}$, $K^+$, $Mg^{2+}$로 이온 치환을 진행하였다. 암모니아성 질소($NH_4-N$)의 흡착량과 제거율은 $Na^+$로 이온 치환된 제올라이트에서 0.66 mg/g과 89.8%로 가장 높은 값을 보였다. 이온 치환된 제올라이트를 이용하여 Mn과 As의 흡착실험을 진행하였다. $Mg^{2+}$로 이온 치환된 제올라이트에서 Mn과 As의 높은 흡착량과 제거율을 보였다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2015년도 제49회 하계 정기학술대회 초록집
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• pp.84.2-84.2
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• 2015

Growing market of electric vehicles such as hybrid, plug-in hybrid, and bare electric vehicles in the world is accelerating the significance of Li-ion batteries as a renewable green energy. According to such market flow, the developing components such as cathode, anode, electrolyte, and separator, composing the Li-ion batteries, is significantly important tasks for the commercialization. In particular, development of the cathode material having high capacity and stable thermal stability is essential for long-distance electric vehicle in the near future. Herein we introduce various applications of Li-ion batteries such as portable electronics, electric vehicles, and energy storage system, and also its research trend, in particular on the cathode materials.

• Bulletin of the Korean Chemical Society
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• 제25권4호
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• pp.471-475
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• 2004

The solubility of N,N'-Bis(salicylidene) ethylenediamine (n-salen) and N,N'-bis(3,5-di-tert-butylsalicylidene) ethylenediamine (t-butyl-salen) was studied with in-situ UV-VIS spectrometer. n-Salen is 3-5 times more soluble than t-butyl-salen in liquid or supercritical $CO_2$. This behavior may be attributed to Lewis acid-base interaction between salen and $CO_2$. The chelation of salen with $Co^{++}$ ion in supercritical condition was confirmed to be fast enough above room temperature. However, the metal ion extraction capability of t-butyl salen is relatively poor because of its low solubility and ionic nature of complex.

• 한국수소및신에너지학회논문집
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• 제26권5호
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• pp.416-422
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• 2015

Lithium Ion capacitor (LIC) is a new storage device which combines high power density and high energy density compared to conventional supercapacitors. LIC is capable of storing approximately 5.10 times more energy than conventional EDLCs and also have the benefits of high power and long cycle-life. In this study, LICs are assembled with activated carbon (AC) cathode and pre-doped graphite anode. Cathode material of natural graphite and artificial graphite kinds of MAGE-E3 was selected as the experiment proceeds. Super-P as a conductive agent and PTFE was used as binder, with the graphite: conductive agent: binder of 85: 10: 5 ratio of the negative electrode was prepared. Lithium doping condition of current density of $2mA/cm^2$ to $1mA/cm^2$, and was conducted by varying the doping. Results Analysis of Inductively Coupled Plasma Spectrometer (ICP) was used and a $1mA/cm^2$ current density, $2mA/cm^2$, when more than 1.5% of lithium ions was confirmed that contained. In addition, lithium ion doping to 0.005 V at 10, 20 and $30^{\circ}C$ temperature varying the voltage variation was confirmed, $20^{\circ}C$ cell from the low internal resistance of $4.9{\Omega}$ was confirmed.