• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2005년도 하계학술대회 논문집 Vol.6
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• pp.244-245
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• 2005

Electrical insulation is one of the most important parts in a high voltage apparatus. Traditionally mineral oils and synthetic esters have been widely used as dielectric coolants for power transformers. Recently, researchers are interested in the environmental friendly vegetable oil from environmental viewpoint. This paper reports on the synthesis and characterization of soybean based ester oils. Two different types of soybean based transformer oils, named as methyl ester and isopropyl ester were synthesized. The synthesis of these esters was achieved by transesterification reactions of soybean oil and alcohol in the presence of catalyst. The GC and NMR spectroscopic analysis of the esters have been performed. The thermal stability of the esters was determined by thermal gravimetric analysis(TGA).

• 한국토양비료학회지
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• 제34권2호
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• pp.145-146
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• 2001

본 분석방법은 토양중에 방향성화합물을 함유한 유류 존재를 스크리닝하는 방법으로 ASTM(The American Society for Testing and Materials)에 등록되어 있으며, 수분 제거제를 이용하여 토양수분에 의한 정량 오차를 줄이고 UV-Spectrophotometer로 정량한다. 오염된 유류의 종류를 알고 있으나 동일한 유류를 구하지 못할 경우에는 일반적으로 동일종에서 얻어진 계수로 농도를 추정하며, 오염된 유류의 특성을 모를 경우에는 본 방법으로 오염여부 판단만이 가능하다. 그러나 토양에 오염된 것과 동일한 유류로 검량선을 작성할 경우에는 대략적인 정량도 가능하며, 분석방법을 요약하면 다음과 같다. 일정량의 토양시료에 CaO를 첨가하여 토양수분에 의한 영향을 제거한 뒤 이소프로필알콜(isopropyl alcohol)로 추출하여 여과한다. 여과액을 254nm의 UV파장에서 흡광도를 측정하여 오염된 것과 동일한 유류로 작성된 검량선을 이용하여 정량한다.

• 한국산학기술학회:학술대회논문집
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• 한국산학기술학회 2003년도 춘계학술발표논문집
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• pp.343-346
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• 2003

본 연구에서는 IPA(isopropyl alcohol)를 분해물질로 선정하여 플라스틱 광섬유(Pastic Optical Fiber, POF)에 TiO₂를 코팅하여 오염물질을 분해하였다. P-25가 코팅된 POF의 표면은 유기계, 무기계, 유ㆍ무기 바인더를 사용한 것 모두 깨끗하였고, 무기계 바인더를 사용하여 코팅한 POF는 부착력이 현저히 떨어졌다. IPA 분해 결과, 무기계 바인더를 사용한 경우, 다른 종류의 바인더와는 다르게 IPA의 초기농도 값이 매우 작게나왔는데 이러한 결과는 반응기에 주입된 IPA가 평형이 될 때까지 기다리는 동안 흡착이 일어났기 때문으로 생각된다. 유기계 바인더를 사용하여 코팅한 POF는 IPA 분해 효율이 매우 저조하였고 유ㆍ무기 바인더를 사용하여 코팅한 POF의 IPA 분해 효율은 우수하였다. P-25와 IPA의 분해 효율이 우수한 유ㆍ무기 바인더의 비율을 10 : 10 : 8, 10 : 6, 10 : 4, 10 : 2로 바꾸어 IPA를 분해한 결과, P-25와 유ㆍ무기 바인더의 비율이 10 : 2일 때 IPA 분해 효율이 가장 우수하였다. 또한 P-25와 코팅액 제조 시 회석제로 사용되는 에탄올의 질량비를 1 : 7, 1 : 11, 1 : 15로 바꾸어 IPA를 분해한 결과, P-25와 에탄올의 비율이 1 : 15 일 때 IPA 분해 효율이 가장 우수하였다.

• 한국표면공학회지
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• 제32권3호
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• pp.456-460
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• 1999

Transparent conducting tin (IV) oxide thin films have been studies and developed for the electrode materials of solar cell substrate. Fabrication of tin oxide thin films by sol-gel method is process development of lower cost photovoltaic solar cell system. The research is focused on the establishment of process condition and development of precursor. The precursor solution was made of tin isopropoxide dissolved in isopropyl alcohol. The hydrolysis rate was controlled by addition of triethanolamine. Dip and spin coating technique were applied to coat tin oxide on borosilicate glass. The resistivity of the thin film was lower than 0.1Ω-cm and the transmittance is higher than 90% in a visible range.

• Bulletin of the Korean Chemical Society
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• 제8권2호
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• pp.79-83
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• 1987

The reduction of a series of 1-substituted benzyl-3-cyanoquinolinium ions (p-$cH_3$, H, p-Br, m-F, p-CN) by sodium borohydride has been investigated. In all cases the products from these reactions were found to be 1, 2-dihydroquinolines over 82% yields. Rates of reduction were measured in basic condition and in solvent system consisting of 4 parts of isopropyl alcohol and 1 part of water by volume. Second order rate constants were obtained for these reactions. When the ratio of [$OH^-$] to [$BH_4^-$] becomes large the observed rate constants ($K_{obs}$) decrease by a small factor. Reaction scheme and rate law are discussed. Bronsted ${\alpha}(=\frac{d\;In\;k}{d\;In\;K})$ obtained by using the value of equilibrium constant K, which was obtained previously, was not 0. Instead, a value of 0.36 was obtained which indicated that the reduction by borohydride was structure-dependent according to the Marcus formalism even though the reaction rate was close to the diffusion limit.

• Bulletin of the Korean Chemical Society
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• 제20권9호
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• pp.1040-1044
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• 1999

A micro porous PTFE membrane desolvator (MMD) was built and evaluated for the on-line removal of organic solvents to facilitate the determination of trace metal contaminants in the solvents by ICP-AES. Three organic solvents, isopropyl alcohol (IPA), methanol, and dimethy sulfoxide (DMSO) were studied. The MMD reduced organic solvent concentration in the sample aerosol stream by 82% to 89%, as indicated by monitoring C(I) emission. Net signal intensity of Fe, Al, and Cu was increasing with higher organic solvent concentration, with the rate of increase being solvent dependent. The signal intensities for Mg and Pb followed the trend with the C(I) signal. Changing the sweep gas flow rate affected the optimum signal intensity. Wine samples were analyzed by the method of standard addition. The concentrations of B, Al, and Mg were determined with a relative precision of less than 2.3%.

• 센서학회지
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• 제28권3호
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• pp.171-176
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• 2019

The biomarkers related to the colorectal cancers and diseases were surveyed and summarized, and an optical electronic nose was researched and developed for their analysis. The prototyped sensor revealed that it could discriminate two gases: ethanol 2000 ppm and $CO_2$ 500 ppm. Furthermore, the sensor demonstrated the potential capability of estimation of $CO_2$ concentration with 95% confidence level. Based on the above experimental results, the developed optical electronic nose was tested with the mixtures of gases (Isopropyl Alcohol, Acetone, Methanol, and Toluene) and the biomarkers were successfully segregated using principal component analysis.

• Elastomers and Composites
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• 제54권2호
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• pp.105-109
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• 2019

Gold nanoparticles were synthesized by reacting potassium tetrachloroaurate ($KAuCl_4$), potassium carbonate ($K_2CO_3$), and isopropyl alcohol in the presence of fullerene oxide [$C_{60}(O)_n$, $n{\geq}1$], which was, in turn, prepared from [$C_{60}$] fullerene and m-chloroperoxybenzoic acid under refluxing conditions. The crystallinity and morphology of the prepared gold nanoparticles were confirmed by UV-vis spectroscopy, X-ray diffraction, and scanning electron microscopy. The activity of the gold nanoparticles in the reduction of 4-nitroaniline was measured in order to determine its capability as a catalyst.

• 한국전기전자재료학회논문지
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• 제36권5호
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• pp.482-487
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• 2023

A carbon-based hybrid resistor was fabricated using carbon nanotube (CNT) paste as an adhesive layer to establish electrically continuous ohmic contacts between CNT sheets and different CNT sheet or copper based metal alloy plates, and its electrical properties were evaluated. CNT sheets were fabricated using vacuum filtration with a CNT solution dispersed in isopropyl alcohol (IPA) solvent. The electrical characteristics of these carbon-based hybrid resistors were investigated. The CNT paste fulfilled the requirements for forming ohmic contacts between CNT sheets and metal alloy plates, which was attributed to the lowest work function difference and excellent wettability at the interface.

• 전기화학회지
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• 제3권1호
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• pp.15-18
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• 2000

태양전지의 전극 기판으로 사용되는 전도성 투명 산화주석 박막의 제조 방법에 대하여 연구하였다. 졸겔법을 이용하여 산화 주석 박막을 제조하는 경우에 저가의 공정으로 대면적의 박막을 얻을 수 있는 장점이 있다. 본 연구에서는 공정 조건의 확립과 전구체의 설정에 중점을 두었다. 전구체 용액을 isopropyl 알코올에 tin isopropoxide를 용해한 용액을 사용하였으며 수화 반응을 억제하기 위하여 triethanolamine(TEA)을 첨가하였다. Corning유리 위에 spinning과 dipping방법을 이용하여 코팅을 하였으며 이후 열처리하여 최종 산화주석 박막을 제조하였다. 이렇게 제조된 박막은 가시광선 영역에서 $90\%$ 이상의 투과도를 보였으며 $0.01\Omega{\cdot}cm$ 이하의 비저항을 나타냈다