Manganese Ferrite의 이온 선택성 막전극에 대한 거동

鄭求春 건국대학교 1988 論文集 Vol.26 No.1

The perovskite which were synthesized by mixing Manganese with Iron to molar ratio of 0.6 : 2.4, 0.8 : 2.2, 1.0 : 2.0, 1.2 : 1.8 and 1.4 : 1.6 were sintered at 900℃, 1000℃, 1100℃. 1200℃, 1300℃, and 2614-2700℃ respectively. When the potential response were measured to ionic concentration by using those electrode, the ionic selectivity was increased on the increasing of sintered temperature. The membrane electrode of Mn1.0Fe2.0O4 perovskite sintered at 2614-2700℃ was responses to Iodide ion(I-), Phosphate ions (PO43- HPO42-, H2PO4-) ant Arsenate ion (AsO43-) ant to Silver ion(Ag+) only among cations.

조선업 용접공의 용접흄 생애누적노출량을 이용한 환기기능 평가

정춘화,임현우,구정완,박정일 大韓産業醫學會 2002 대한직업환경의학회지 Vol.14 No.4

목적 : 조선업 용접공들의 용접흄 생애 누적노출량을 이용하여 그들의 환기기능을 평가하기 위하여 본연구를 실시하였다. 방법 : 1개 대규모 조선소에서 용접흠에 5년이상 노출된 남자근로자 241명과 대조군으로 사무직 남자 근로자 80명을 대상으로 개인별 생애 누적노출량을 산출하였고 환기기능으로서 노력성폐활량(FVC), 1초량(FEV_1), 1초율(FEV_1%), 최대중간호기 속도(MMF), 최고호기기류속도(PEER)와 호기 FVC의 50%, 75% 시점에서의 최대호기기류인 FEF_50, FEF_75를 얻고저 노력성 호기곡선과 최대호기기류-용량곡선을 측정하여 분석한 결과는 다음과 같았다. 결과 : FEF_50과 FEF_75의 예측치에 대한 백분율(%pred)의 평균은 노출군이 대조군보다 유의하게 감소하였고 MMF는 감소하는 경향을 보였다. 현재의 노출수준 증가에 따라 감소하는 유의한 환기지수는 없었다. 환기지수 중 MMF, FEF_50 및 FEF_75는 노출 기간이 길수록 유의하게 감소하였다. 노출수준×노출기간으로 산출한 용접흄 누적노출량(C1)이 증가함에 따라 최대노출군에서 유의하게 감소한 환기지수는 FEF_75 뿐이었다. 노출수준, 노출기간, 환기시설, 생산량, 보호구사용, 용접봉 및 와이어 종류 등의 변수들을 고려하여 산출한 용접흠 누적 노출량(C2)이 증가함에 따라 최대노출군에서 유의하게 감소한 환기지수는 FEF_75이었으며 MMF 및 FEF_50은 감소하는 경향을 보였다. 또한 환기지수중 MMF, FEF_50 및 FEF_75의 경우 생애 누적노출량(C2)이 증가함에 따라 비정상적인 환기기능을 보인 근로자 비율이 유의하게 증가하였다. 결론 : 본 연구결과는 노출 관련 요인들을 고려하여 산출한 생애 누적노출량(C2)을 이용하여 용접흠에 노출된 근로자들의 환기기능을 평가하는데 있어서 MMF, FEF_50 및 FEF_75가 유용한 지수이었다. Objectives : This study was conducted to evaluate the ventilatory function in shipyard welders using the lifetime cumulative exposure to welding fumes. Methods : Ventilatory function tests were performed on 241 male welders at one large shipuad. exposed to welding fumes for over five years, and was compared to 80 male control subjects. Ventilatory function indices, such as forced vital capacity(FVC). one-second forced expiratory volume(FEV), rato of FEV_1 to FVC(FEV_1%), maximal mid-expira-tory flow(MMF). peak expiratory flow rate(PEER) and maximal expiratory flow at 50 and 75% of expited FVC(FEF_50 and FEF_75), were obtained by analuyzing forced expiratory spirograms and maximal expiratory flowvolume curves that were simultaneously mea-sured by an Impulse ocillometry(IOS) program in the standing position. Results : FEF_50 and FEF_75 expressed as a percentage of the predicted values were significatly lower in the exposure group than in the controls, and the MMF tended to decrease. The mens of all the ventilatory indices, expressed as percentage of the predicted values, were not significantly increased at the current exposure levels. The MMF, FEF_+50 and FEF_75, expressed as a percentage of the predicted values, were significantly decreased with an increase in exposure duration. Onlu the FEF_75, expressed as a percentage of the predicted value, was significantly decreased with an increase in the cunulative exposure to welding fumes(C1). The FEF_75, expressed as a percentage of the predicted value, was significantly decreased with an increase in the cumulative exposure to welding fumes(C2), The above parameters were calculated to consider the durrent exposure level, exposure duration, application of the ventilator sustem, production rate, personal protection device, electrode and swelding wire. The MMF and FDF_50, expressed as a percentage of the predicted value, tended to decrease, The proportion of workers with abnormal MMF, FDF_50 and FDF_75 were significantly increased with an increase in the cumulative exposure to welding fumes(C2). Conclusions : These findings suggested that the MMF, FDF_50 and FDF_75 are sensitive and practical indices for the evaluation of the ventilatory function of workeers exposed to welding fumes, when the lifetime cumulative exposure(C2) is considered as a factor affedting exposure.

Silicone-pyridine에 대한 Chlorophyll-a와 -b의 혼합착물의 형광연구(Ⅳ)

박면용,박택규,정구춘 建國大學校基礎科學硏究所 1987 理學論集 Vol.12 No.-

클로필-a와 -b를 혼합물의 상태로 1:2, 1:4, 1:6의 polydimethylethylsilane(0-2 -pyridylethyl methylsilane)에 Mg-pyridine 착물로 디에틸에테르중에서 결합시키고 중합체 사슬을 통한 에너지 이동을 연구하였다. Chl-b에 대한 Chl-a의 첨가량이 증가할수록 Chl-a의 혼합비(5:1, 3:1, 1:1)에 따라 형광수득율이 증가하였다. 반대로 Chl-b가 Chl-a에 비하여 첨가량이 증가할수록 형광수득율이 감소하였다. 최대 형광세기는 Chl-a와 Chl-b에 대하여 결합한 pyridine의 당량농도에서 나타났다. Chl-a에 의하여 흡수된 에너지는 중합체의 사슬을 통하여 Chl-b로 이동하였고 그 이동경향은 dimer>tetramer>hexamer의 순서로 증가하였다. The chlorophyll-a and -b have been bound 1:2, 1:4 and 1:6 polydimethyl ethyl silane(0-2-pyridylehylmethylsilane) as the mixed state to form the complex compound of Mg atom on chlorophyll and pyridine on the polymer in diethyl ether, and studied about the energy migration through the polymer chain in the same solvent. The more chl-a were added to chl-b the more increased fluorescence yields of chl-b were shown it to match for the mixed ratios of chl-a: chl-b in the order of 5:1, 3:1 and 1:1, while chl-a was shown the more decreased fluorescence yields according as the more chl-b were added. The maximum fluorescence intensity were appeared at equivalent pyridine concentration bound to the chl-a and -b. The absorbed energy by chl-a were transfered to chl-b through the chain, and the migration tendencies were on the increase of dimer>tetramer>hexamer.

중 ·소의 대동남아 외교정책

정천구(Chun Koo Chung) 한양대학교 아태지역연구센터 1988 중소연구 Vol.12 No.2

티탄산칼슘 세라믹 이온 - 선택성 막전극

정구춘(Koo-Chun Chung),김명숙(Myoung-Sook Kim),김병수(Byung-Soo Kim),박면용(Myon-Yong Park),소헌영(Hun-Young So) 한국분석과학회 1990 분석과학 Vol.3 No.1

4-tert-Butylbenzo-15-crown-5를 이용한 납 이온 선택성 고체 접촉 전극에 관한 연구

정구춘 ( Koo Chun Chung ),이민아 ( Min A Lee ) 한국환경분석학회 2009 환경분석과 독성보건 Vol.12 No.1

티탄산스트론튬 세라믹 이온 - 선택성 막 전극

정구춘(Koo-Chun Chung),김명숙(Myoung-Sook Kim),김병수(Byung-Soo Kim),김형곤(Hyung-Gon Kim),박면용(Myon-Yong Park),소헌영(Hum-Young So) 한국분석과학회 1990 분석과학 Vol.3 No.1

베트남과 중 · 소분쟁

정천구(Chun Koo Chung) 한양대학교 아태지역연구센터 1983 중소연구 Vol.7 No.4

Development of World's Largest 21.3' LTPS LCD using Sequential Lateral Solidification(SLS) Technology

Kang, Myung-Koo,Kim, Hyun-Jae,Chung, Jin-Koo,Kim, Dong-Beom,Lee, Su-Kyung,Kim, Cheol-Ho,Chung, Woo-Seok,Hwang, Jang-Won,Joo, Seung-Yong,Meang, Ho-Seok,Song, Seok-Chun,Kim, Chi-Woo,Chung, Kyu-Ha The Korean Infomation Display Society 2003 Journal of information display Vol.4 No.4

The world largest 21.3" LTPS LCD has been successfully developed using SLS crystallization technology. Integration of gate circuit, transmission gate and level shifter was successfully performed in a large area display. Uniform and high performance of high quality grains of SLS technology make it possible to realize a uniform large size LTPS TFT-LCD with half the number of data driver IC's that is typically used in a-Si LCD. High aperture ratio of 65 % was achieved using an organic inter insulating method which lead to a high brightness of 500 cd/$cm^2$.

Urea-formaldehyde resin을 사용한 고체상 전극의 특성

정구춘,임주희 建國大學校基礎科學硏究所 2001 理學論集 Vol.26 No.-

본 연구에서는 전극의 frame material로 urea-formaldehyde resin을 합성하여 사용하고, 중성운반체로 TBA, 고체지지체로 PVC, 가소제로 DOP, o-NPOE, 친지방성첨가제로 NaTPB, KTpCIPB를 사용한 Ag/AgCl 고체상 수소이온 선택성 액체 막 전극을 제조하였다. 중성운반체의 함량에 따라 변화시킨 전극중 1% TBA 전극이 수소이온 감응범위가 pH 1.0-10.0이었으며, Nernstian 기울기는 54.33mV/pH로 가장 우수한 감응을 나타내었다. 가소제의 변화에 의한 Nernstian 감응기울기는 o-NPOE가 DOP보다 매우 좋은 감응도를 나타냈으며, 친지방성 첨가제의 변화에 의한 Nernstian 감응 기울기는 KTpCIPB가 NaTPB와 비교해서 훨씬 넓은 pH범위에서 선형적인 결과를 나타내었다. 또한 위의 전극은 알칼리나 알칼리 토금속에 대한 방해효과가 기존의 전극들보다 낮게 나타났으며, 감응 기울기도 conventional electrode나 coated wire 형태의 전극에 비하여 높은 것으로 나타났다. The hydrogen ion-selective Ag/AgCl solid-state electrode was prepared by using urea-formaldehyde resin as frame material and KCl as electrolyte. The electrode membrane was incorporated tribenzylamine (TBA) as a neutral carrier, PVC as a matrix, sodium tetraphenyl borate(NaTPB) and potassium tetrakis- (4-chlorophenyl) borate(KTpCIPB) as a liphophilic agent and dioctylphthalate(DOP) and o-nitrophenyloctyl ether(o-NPOE) as a plasticizer. The response potentials of the electrodes contained 1%, 3% and 5% TBA were shown linearities to hydrogen ion in the range of pH 1.0-10.0, pH 1.0-10.0, pH 1.0-9.0 and as slope of 54.33mV/pH, 52.57mV/pH, 40.62mV/pH, respectively. The electrode contained 1% TBA exhibits better slope than electrodes contained 3% and 5% TBA. Then the properties of the electrode based on 1% TBA were studied in detail. The electrode were appeared low interference effect on the alkaline earth metal ions but high on the alkali metal ions. Finally when this electrode compared with internal solution electrode and coated wire type electrode(CWE), response slope is remarkably enhanced than internal reference solution electrode (48.33mV/pH) and CWE (53.31mV/pH).