• The Journal of Natural Sciences
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• v.12 no.1
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• pp.81-84
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• 2002

We developed new process for the large scale preparation of pyrazole sulfonyl urea and pyrazole sulfonyl urea carboalkoxyl benzene sulfonyl urea 1) in high yields and convenience. As compound with know procedure this procedure have found to be far large scale preparation. During the preparation we obtains two new sulfonyl urea 5a and 5b in 70% and 74% ( purified by crystallization).

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2008.11a
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• pp.482-487
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• 2008

성능이 우수한 다성분계 전극을 개발하기 위하여 Ru를 주 전극성분으로 Pt, Sn, Sb 및 Gd를 보조 전극성분으로 하여 3, 4성분계 전극의 성능과 산화제 생성량 및 전극 표면 분석을 행하여 다음의 결과를 얻었다. 1. 2분 동안 단위 W당 제거된 RhB 농토는 Ru:Sn:Sb=9:1:1 > Ru:Pt:Gd=5:5:1 > Ru:Sn=9:1 > Ru:Sn:Gd=9:1:1 > Ru:Sb:Gd=9:1:1로 나타났다. Ru:Sn:Sb=9:1.1 전극에서 발생하는 free Cl, ClO$_2$ 및 H$_2$O$_2$농도가 다른 전극보다 높은 것으로 나타나 산화제 생성경향과 RhB 분해율과는 상관관계가 있는 것으로 사료되었다. 4성분계 전극 중에서 Ru:Sn:Sb:Gd 전극의 성능이 가장 우수한 것으로 나타났으나 3성분계 전극인 Ru:Sn:Sb=9:1.1 전극보다 성능이 떨어지는 것으로 나타났다. Ru:Sn:Sb=9:1:1 전극에서 생성되는 산화제 농도가 다른 두 종류의 산화제 농도보다 높은 것으로 나타났고 4성분 전극의 경우 Ru:Sn:Sb:Gd 전극의 산화제 농도가 Ru:Sn:Sb:Gd 전극이 높거나 유사한 경우로 나타나 산화제 생성 경향과 RhB분해 능과는 상관관계가 있는 것으로 나타났다. 초기 RhB 분해 속도가 높은 전극의 COD 제거율도 높은 것으로 나타났다. OH 라디칼은 발생하지 않지만 염소계 산화제 농도가 높고 RhB제거율이 높아 Ru를 주 성분으로 한 전극의 RhB분해는 주로 간접 산화작용에 의한 것이며, 개발된 3, 4성분계 산화물 전극은 간접 산화용 전극임을 알 수 있었다. 에칭을 하기 전의 Ti판은 표면이 매끄러운 것으로 나타났으며, 35% 염산으로 에칭한 후의 Ti메쉬는 매우 거친 표면조직을 가지는 것을 관찰할 수 있었다. Ru:Sn:Sb=9:1:1 전극과 Ru:Sn:Sb:Gd 전극의 SEM 사진을 관찰한 결과 두 전극 모두 전극 물질이 균일하게 도포되어 있었으며, 두 전극 모두 열소성을 통해 전극 성분을 코팅할 때 발생하는 "mud crack"이 발생한 것이 관찰되었다 EDX 분석에서 Cl이 관찰되었는데, 전극 성분의 불완전 산화로 인한 비양론적 산화물 때문이며 이는 RhB 분해성능과 관련 있는 것으로 사료되었다.

• Journal of Advanced Marine Engineering and Technology
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• v.41 no.3
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• pp.216-221
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• 2017

Diesel engines have the highest brake thermal efficiency among internal combustion engines. Therefore, they are utilized in medium and large transportation vehicles requiring large amounts of power such as heavy trucks, ships, power generation systems, etc. However, diesel engines have a disadvantage of generating large quantities of nitrogen oxides during the combustion process. Therefore, the authors tried to reduce the amount of nitrogen oxides in marine diesel engines using a wet-type exhaust gas cleaning system utilizing the undivided electrolyzed seawater method. In this method, electrolyzed seawater in injected into the harmful gas discharge from the diesel engine using real seawater. The authors investigated the reduction of NO and NOx from the pH value, available chlorine concentration, and the temperature of electrolyzed seawater. The results of this experiment indicated that when the electrolyzed seawater is acidic, the NO oxidation rate in the oxidation tower is higher than that when the electrolyzed seawater has a neutral pH. Likewise, the NO oxidation rate increased with the increase in concentration of chlorine. Further, it was confirmed that the electrolyzed seawater temperature had no effect on the NO oxidation rate. Thus, the NOx exhaust emission value produced by the diesel engine was reduced by means of electrolyzed seawater treatment.

• Journal of Korean Society of Environmental Engineers
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• v.31 no.7
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• pp.549-556
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• 2009

In situ chemical oxidations (ISCO) are technologies for destruction of many contaminants in soil and groundwater, and persulfate has been recently studied as an alternative ISCO oxidant. Trichloroethylene (TCE) and tetrachloroethylene (PCE) were chosen for target organic compounds. The objective of this study is to demonstrate the influence of initial pH (3, 6, 9, 12), oxidant concentrations (0.01, 0.05, 0.1, 0.3, 0.5 M), and contaminants concentrations (10, 30, 50, 70, 100 mg/L) on TCE/PCE degradation by persulfate oxidation. The maximum TCE/PCE degradation occurred at pH 3, and the removal efficiencies with this pH condition were 93.2 and 89.3%, respectively. The minimum TCE/PCE degradation occurred at pH 12, and the removal efficiencies were 55.0 and 31.2%, respectively. This indicated that degradation of TCE/PCE decreased with increasing the initial pH of solution. Degradation of TCE/PCE increased with increasing the concentration of persulfate and with decreasing the concentration of contaminants (TCE/PCE). The optimum conditions for TCE/PCE degradation were pH 3, 0.5 M of persulfate solution, and 10 mg/L of contaminant concentration. At these conditions, the first-order rate constants ($k_{obs}$) for TCE and PCE were 1.04 and 1.31 $h^{-1}$, respectively.

• Journal of the Korean Electrochemical Society
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• v.16 no.2
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• pp.74-80
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• 2013

We investigate the formation of nanoporous gold (NPG) surfaces by anodization in three carboxylic acid (formic acid, acetic acid, and propionic acid) solutions and the electrochemical oxidation of glucose at NPG surfaces. Among three carboxylic acids, formic acid provided the most efficient conditions for NPG formation towards glucose oxidation. The optimized conditions during anodization in formic acid for glucose oxidation were 5.0 V of applied potential and 4 hour of reaction time. Electrocatalytic activities for glucose oxidation at NPG surfaces prepared by anodization in carboxylic acids were examined under the absence and presence of chloride ions, which were compared to those observed at NPG prepared in oxalic acid solutions. The application NPG prepared by optimized anodization conditions in formic acid to the amperometric detection of glucose was demonstrated.

• Proceedings of the Korean Institute of Industrial Safety Conference
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• 2002.11a
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• pp.131-135
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• 2002

오존은 공업적으로 상ㆍ하수처리, 펄프표백, 반도체절연막 형성, 레지스트막 제거 등 수많은 분야에 이용되고 있으며, 강력한 산화력을 갖고 있으면서 자연분해 해서 산소로 돌아가 잔류독성을 남기지 않기 때문에 환경문제의 근본적인 해결에 도움이 되는 물질로서 큰 주목을 받고 있다. 그러나 생산비용이 극히 높기 때문에 오존 이용이 바람직한 경우라 할지라도 입수가 용이하고 비교적 염가인 염소를 대용하는 일이 많다.(중략)

• Proceedings of the Korean Institute of Surface Engineering Conference
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• 2015.11a
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• pp.265-265
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• 2015

Zinc Oxide 층은 역구조 유기 태양전지(Inverted Organic Photovoltaics, IOPV)에서 전자 수집 층으로 사용되는데, 전자 수집 및 전기 전도도 증가를 위하여 일반적으로 3차원 나노 구조체 및 양이온이 도핑된 Zinc Oxide 층이 사용된다. 본 연구에서는 저온 3차원 나노 구조체 및 음이온이 도핑된 Zinc Oxide 층을 적용하였으며, 그 결과 전자 수집 향상, 전기 전도도의 증가에 의하여 광전변환 효율(Power Conversion Efficiency, PCE)이 향상됨을 확인할 수 있었다.

• Proceedings of the Membrane Society of Korea Conference
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• 1993.04a
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• pp.30-30
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• 1993

막 자체가 갖는 성능은 역삼투공정의 효율성에 영향을 미치는 상당히 중요한 인자이다. 따라서 역삼투막이 가져야 할 조건은 높은 염배제율 뿐만아니라 물의 투과유량도 커야하며, 가수분해나 산화에 의한 성능저하가 없어야 한다. 폴리아미드막을 이용한 역삼투공정은 이미 보편화되어 있으며, 특히 가교폴리아미드를 선택층으로 가지는 박층복합막은 그 성능이 우수한 것으로 알려져왔다. 폴리아미드막은 우수한 물투과유량 및 염배제율을 가지고 있어 이미 상품화 되어있지만 내화학성의 향상에 있어서는 아직도 연구개발중에 있으며, 특히 막세척시 사용되는 염소에 대한 저항성 향상이 절실히 요구되고 있는 실정이다.

• Journal of the Korean Vacuum Society
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• v.2 no.2
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• pp.188-198
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• 1993

We have developed a technique for growing thin oxides (6~10 nm) by the Last step TCA method. N-channel metal-oxide-semiconductor (n-MOS) capacitor and n-channel metal-oxide-semiconductor field-effect transistor's (MOSFET's) having a gate oxide with chlorine incorporated $SiO_2/Si$ interface have been analyzed by electrical measurements and physical methods, such as secondary ion mass spectrometry (SIMS) and electron spectroscopy for chemical analysis (ESCA). The gate oxide grown with the Last strp TCA method has good characteristics as follows: the electron mobility of the MOSFET's with the Last step TCA method was increased by about 7% and the defect density at the $SiO_2/Si$ interface decreases slightly compared with that with No TCA method. In reliability estimation, the breakdown field was 18 MV/cm, 0.6 MV/cm higher than that of the gate oxide with No TCA method, and the lifetime estimated by TDDB measurement was longer than 20 years. The device lifetime estimated from hot-carrier reliability was proven to be enhanced. As the results, the gate oxide having a $SiO_2/Si$ interface incorporated with chlorine has good characteristics. Our new technique of Last step TCA method may be used to improve the endurance and retention of MOSFET's and to alleviate the degradation of thin oxides in short-channel MOS devices.

• Journal of Korean Society of Water and Wastewater
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• v.19 no.5
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• pp.625-631
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• 2005

Disinfection characteristics of mixed oxidants produced by mean of electro-chemical method were evaluated. Inactivation rate of B. subtilis spore on the mixed oxidants were similar with that of chlorine. Based on the experimental results, activation energy of mixed oxidants and chlorine with B. subtilis spore at pH 8.3 were calculated as 30.8, $34.7kJ{\cdot}mol^{-1}$ respectively. UV absorption spectrum of both chlorine and mixed oxidants present similar. Molar extinction coefficients of chlorine and mixed oxidants at 292nm, which is maximum absorption wavelength of $OCl^-$ were 357, $377M^{-1}cm^{-1}$, respectively. Disinfectant decay rate and formation rate of THM in the S WTP filtrate also shows insignificant difference for both mixed oxidants and chlorine. In consequent, it was confirmed that high portion of chlorine presents in the mixed oxidants.