• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 추계학술대회 논문집
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• pp.328-328
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• 2007

$SnO_2$ has a high potential for electric and electronic applications. We have anodized pure tin metal and nano porous tin oxide film was obtained on pure Sn. Nano porous tin oxide were grown by anodization in nonaqueous-base electrolytes at different potentials between 5 V and 100 V. Pore size of ~100nm was observed by FE-SEM. Pore sizes as a function of applied voltage and anodizing time were characterized. We obtained nano porous tin oxide film having an uniform pore size at low temperature. High specific surface area of $SnO_2$ will be very useful for gas sensor, lithium battery, and dye sensitized solar cell.

• 한국연초학회지
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• 제35권1호
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• pp.20-27
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• 2013

An Electronic Nose(E-Nose) and Gas Chromatography/Mass Spectroscopy (GC/MS) are meanwhile conventional technique to analyze volatile materials in many industries (e.g., food, medicine, environment) and have broad acceptance in the analysis of tobacco products. In this study, an experiment where tin oxide gas sensor array responses and GC/MS profiles are used to characterize the volatile compounds of different cigarettes at the same time is performed and the measurements of two instruments are compared for cigarette samples with a known chemical information. E-Nose and GC/MS were employed to differentiate and match flavored cigarettes with commercial tobacco flavoring agents (lavender, vanilla, peppermint, orange, star anise). For verifying reliability of two systems, the analyses were conducted in terms of amount of flavors in each cigarettes using partial least squares (PLS) and with the principal components analysis (PCA). Various chemical sensors and GC/MS data was reduced into two principal factors (PC1, PC2) for being distinguished with visualized regions. Both systems provided adequate results for odor characteristics of cigarettes in this study with each instrument having its own advantages and disadvantages.

• 열처리공학회지
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• 제24권2호
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• pp.87-91
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• 2011

Single layer Sn doped $In_2O_3$ (ITO) films and ITO 50 nm / Au 10 nm / ITO 40 nm (IAI) multilayer films were prepared with electron beam assisted magnetron sputtering on glass substrates. The effects of the Au interlayer, post-deposition atmosphere annealing and intense electron irradiation on the methanol gas sensitivity were investigated at room temperature. As deposited ITO films did not show any diffraction peaks in the XRD pattern, while the IAI films showed the diffraction peak for $In_2O_3$ (400). In this study, the gas sensitivity of ITO and IAI films increased proportionally with the methanol vapor concentration and an intense electron beam irradiated IAI film shows the higher sensitivity than the others film. From the XRD pattern, it is supposed that increased crystallization promotes the gas sensitivity. This approach is promising in gaining improvement in the performance of IAI gas sensors used for the detection of methanol vapor at room temperature.

• 한국재료학회지
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• 제28권8호
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• pp.466-473
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• 2018

Nickel oxide(NiO) thin films, nanorods, and carbon nanotube(CNT)/NiO core-shell nanorod structures are fabricated by sputtering Nickel at different deposition time on alumina substrates or single wall carbon nanotube templates followed by oxidation treatments at different temperatures, 400 and $700^{\circ}C$. Structural analyses are carried out by scanning electron microscopy and x-ray diffraction. NiO thinfilm, nanorod and CNT/NiO core-shell nanorod structurals of the gas sensor structures are tested for detection of $H_2S$ gas. The NiO structures exhibit the highest response at $200^{\circ}C$ and high selectivity to $H_2S$ among other gases of NO, $NH_3$, $H_2$, CO, etc. The nanorod structures have a higher sensing performance than the thin films and carbon nanotube/NiO core-shell structures. The gold catalyst deposited on NiO nanorods further improve the sensing performance, particularly the recovery kinetics.

• 마이크로전자및패키징학회지
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• 제15권4호
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• pp.101-106
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• 2008

이산화질소를 감지할 수 있는 센서물질로 Pd과 탄소 나노튜브(CNT)가 첨가된 $SnO_2$ 박막을 스핀코팅으로 제조하였으며, 동 시편의 이산화질소에 대한 감지 특성을 $200^{\circ}C$ 및 $1ppm{\sim}5ppm$의 $NO_2$ 농도 하에서 측정하였다. 센서시편의 전기저항은 $NO_2$ 기체의 노출과 농도에 따라 증가 하였으며, Pd이 3wt%로 첨가된 시편의 감도는 26.5로 첨가전의 감도에 비하여 10배 증가하였다. 또한 $SnO_2$ 모체에 첨가한 CNT의 량에 따라서도 감도는 증가 하였으며, 0.225wt% CNT 첨가 시 5ppm의 $NO_2$ 농도에서 감도 값은 72이었다.

• 센서학회지
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• 제15권6호
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• pp.406-410
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• 2006

The films of indium oxide $In_{2}O_{3}$) were deposited onto $SiO_{2}$ coated Si wafers by a thermal evaporation method. Substrate temperature was varied from $25^{\circ}C$ to $300^{\circ}C$. Deposition rate increased to $250^{\circ}C$ and then decreased rapidly. The crystallographic properties and surface morphologies of the films were investigated by X-ray diffraction (XRD) and scanning electron microscope (SEM), respectively. The films deposited at $250^{\circ}C$ were found to have a nanobelt structure. Resistor-type gas-sensors were fabricated with $In_{2}O_{3}$ films using Pt as electrodes. The resistance variation of $In_{2}O_{3}$ films with the concentration of NO gas was measured. The $In_{2}O_{3}$ films deposited at $250^{\circ}C$ showed the highest sensitivity to the NO gas.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 정기총회 및 창립40주년기념 학술대회 학회본부
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• pp.245-247
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• 1987

In this thesis, ZnO semiconductor gas sensors doped by the $Al^{3+}$ were fabricated by the miexed oxide method. The specimens were sintered for 5(hr) at $1000-1200^{\circ}C$ and the I-V, sensitivity were investigated in acetone gas or ammonia gas. As a result, I-V curves of specimens as a function of temperature variation showed characteristics of linear resistor that the current was proportional to the, temperature at constant voltage. For the sensitivity of acetone, 1Wt $Al^{3+}$-ZnO has the hight 0.91, ammonia gas, 2Wt $Al^{3+}$-ZnO specimen has the hight 0.90. Hence, the operating temperature of specimens were both $300^{\circ}C$.

• 한국정보통신학회논문지
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• 제18권9호
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• pp.2197-2202
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• 2014

본 연구에서는 팔라듐 (Pd) 나노선으로 구성된 센서의 고감도 수소검지능력에 대해서 조사하였다. 팔라듐 나노선은 알루미늄 양극 산화막 (AAO : anodic aluminum oxide) 채널에 전기도금법을 이용하여 성장시켰으며, 수산화나트륨 수용액을 이용하여 나노선을 분리한 후 포토 리소그래피와 전자빔 리소그래피 공정 및 리프트오프 공정을 사용하여 금속나노선 수소센서를 제작하였다. 2%의 수소에서는 1.92% 의 민감도가, 0.1% 의 수소에서는 0.18% 의 민감도가 변하는 고감도 특성을 얻었으며, 이는 팔라듐 나노선의 저항은 수소의 흡착과 탈착에 의존하기 때문이다. 따라서 상온에서 고감도 수소 가스 검출을 위하여 팔라듐 나노선이 응용될 수 있을 것으로 기대한다.

• 한국식품조리과학회지
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• 제14권5호
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• pp.541-546
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• 1998

자생 누룩치의 휘발성 향미성분을 연속수증기증류 장치로 추출한 후 GC, GC/MS로 분석하여 31개의 휘발성 향미성분이 확인되었는데, 탄화수소류가 15종으로 전체 peak area의 64.98%를 차지하였고 알데히드류 4종 9.54%, 케톤류 1종 0.16%, 알코올류 5종 7.65%, 에스테르류 2종 2.06%, 산류 3종 2.0% 및 옥사이드류 1종 2.75%로 이루어져 있었다. 탄화수소류 중 mono-terpenes은 peak area 0.54% 및 sesquiterpenes은 52.11% 를 차치하였다. 누룩치의 주요 휘발성 향미성분은 sesquiterpenes인 (Z)-$\beta$-farnesene, (Z, E)-$\alpha$-farnesene 및 farnesene으로 사료된다. Headspace법에 의하여 신선한 누룩치의 휘발성 향미성분을 포집하여 전자코로 분석한 결과, 알코올류와 같은 극성화합물이 가장 많이 감지되었고 알데히드류, 탄화수소류 순서로 감지되었다. 또한 건조된 누룩치는 신선한 시료와 유사한 향미성분 패턴을 보였으나, 각 sensor의 저항치가 현저히 낮아 건조된 시료의 휘발성 향미성분이 비교적 적음을 확인하였다.

• 한국수소및신에너지학회논문집
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• 제16권1호
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• pp.9-16
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• 2005

We studied the electrochromic properties of hydrated amorphous ruthenium oxide ($RuO_2{\cdot}xH_2O$) thin films using in-situ Raman spectroscopy during electrochemical charging/discharging cycles. We have found that the principal effect of hydrogen insertion into $RuO_2{\cdot}xH_2O$ is reduction of $Ru^{4+}\;to\;Ru^{3+}$, and not formation of new bonds involving hydrogen. We compared the changes in the Raman spectrum of a gasochromic $Pd/RuO_2{\cdot}xH_2O$ film as it is exposed to hydrogen gas with that of electrochemical hydrogen insertion. We tested the changes in the optical transmission of the $Pd/RuO_2{\cdot}xH_2O$ film when exposed to hydrogen gas.