• 한국대기환경학회지
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• 제15권4호
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• pp.417-428
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• 1999

The measurement of VOSCs(volatile organic sulfur compounds) in the air is nowadays a very important environmental research field. It is, however, very difficult because the concentration of the VOSC in ambient air is usually very low and the high reactivity makes it difficult to keep in container without loss of recovery. In this study, sampling method with cryogenic preconcentration is evaluated for analysis of atmospheric VOSC such as $CH_3SH,\;CH_3CH_2SH,\;CH_3SCH_3,\;CS_2,\;CH_3SSCH_3,\;CH_3SCH_2SCHA_3,\;and\;C_2H_5SSC_2H_5$ analyzed by GC-MS or GC-FID. Repeatabilities of measurement accompanied with preconcentration for 3-successive runs were in the range of 0.2~1.0% as a relative standard deviation. Stabilities up to 13 days were measured in 6 L canister and 10 L tedlar bag filled with VOSCs in ppb level. Higher stability was observed in tedlar bag as compared to canister with glass coated inner walls, and thiol compounds show dramatic losses in canister within 2~3 days. It is found that recovery over 70% was obtained in a week for all tested VOSCs when the compounds from ambient air matrix were stored in tedlar bag. It is also found that the stabilities of VOSCs are depending on humidity and coexisting compounds in matrix gas due to sample adsorption onto inner surface and reactivity. The results indicate the possibility and limitations of VOSC analysis in ambient air using container sampling method with cryogenic preconcentration.

• 컴퓨터교육학회논문지
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• 제10권6호
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• pp.69-77
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• 2007

본 논문에서는 가상실험실 설계에 필수적인 전자계측장비의 주요기능을 자바애플릿을 이용하여 소프트웨어적으로 구현하였다. 구현된 가상전자계측장비는 가상아나로그 멀티미터, 가상신호발생기, 가상오실로스코프이며, 웹상에서 학습자가 간단한 마우스조작을 통해 가상실험이 가능하도록 하였다. 또한, 구현된 가상전자계측장비의 유효성을 입증하기 위해 주로 전자계측장비의 사용법에 대한 이해를 돕는 가상실험을 구성하였다. 가상아나로그 멀티미터는 OHM, ACV, DCV, DCA를 측정할 수 있는 4가지 실험이 구축되어 있고, 가상신호발생기의 경우 신호발생기에서 주로 다루는 주파수 값을 변화시키거나 삼각파, 구형파, 사인파를 발생시켜 가상오실로스코프로 확인할 수 있도록 하였다. 가상오실로스코프의 경우 두 개의 채널을 이용하여 측정할 수 있는 요소(전압, 전류)를 확대기능을 추가하여 좀 더 세밀하게 측정할 수 있도록 하였으며, 트리거, 커서, 파형의 합성등과 같은 여러 가지 유용한 기능들을 구현하였다. 구현된 가상전자계측장비는 자바클래스 형태로 구현하였기 때문에 가상실험실 구성형태에 따라 여러 가지 다양한 방법으로 활용이 가능하다.

• Journal of the Optical Society of Korea
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• 제18권1호
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• pp.9-14
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• 2014

We numerically investigate the effect of sunlight polarization on the absorption efficiency of V-shaped organic solar cells (VOSCs) using the finite element method (FEM). The spectral distribution of absorbance and the spatial distribution of power dissipation are calculated as a function of the folding angle for s-and p-polarized light. The absorption enhancement caused by the light-trapping effect was more pronounced for s-polarized light at folding angles smaller than $20^{\circ}$, where s-polarized light has a relatively larger reflectance than p-polarized light. On the other hand, the absorption efficiency for p-polarized light is relatively larger for folding angles larger than $20^{\circ}$, where the smaller reflectance at the interface of the VOSC is more important in obtaining high absorption efficiency.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.298-298
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• 2013

Finding renewable and clean energy resources is essential research to solve global warming and depletion of fossil fuels in modern society. Recently, complex harvesting of energy from multiple sources is available in our living environments using a single device has become highly desirable, representing a new trend in energy technologies. We report that when simultaneously driving the fusion and composite cells of two or more types, it is possible to make an affect the other cells to obtain a greater synergistic effect. To understand the coupling effect of photovoltaic and piezoelectric device, we fabricate the serially integrated hybrid cell (s-HC) based on organic solar cell (OSC) and piezoelectric nanogenerator (PNG). The size of increased voltage peaks when OSC and PNG are working on is larger than the case when only PNG is working. This voltage difference is the Voc change of OSC, not the voltage change of PNG and current density difference between these two cases is manifested more clearly. When the OSC and PNG are working in s-HC at the same time, piezoelectric potential (VPNG) is generated in ZnO and theoretical total voltage is sum of voltage of an OSC (VOSC) and VPNG. However, electrons from OSC are influenced by piezoelectric potential in ZnO and current loss of OSC in whole circuit decreases. As a result, VOSC increases temporarily. Current shows the similar behavior. PNG acts a resistance in the whole circuit and current loss occurs when the electrons from OSC pass through the PNG. But piezoelectric potential recover current loss and decrease the resistance of PNG. Our PNG can maintain piezoelectric potential when the strain is held owing to the LDH layer while general PNG cannot maintain piezoelectric potential. During the section that strain is held, voltage enhancement effect is maintained and same effect appeared even turn off the light. Actually at this time, electrons in ZnO nanosheets move to LDH and trapped by the positive charges in this layer. After this strain is held, piezoelectric potential of ZnO nanosheets is disappeared but potential difference which is developed by negative charge dominant LDH layer is remained. This potential acts similar role like piezoelectric potential in ZnO. Electrons from the OSC also are influenced by this potential and the more current flows.

• 한국결정성장학회지
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• 제20권3호
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• pp.153-157
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• 2010

본 연구에서는 제강슬래그의 재활용 범위를 확대하기 위하여 제강슬래그를 접촉여재로 활용한 유기화합물의 흡 착성능을 평가하였다. 또한 표면에 미세한 기공을 가지고 있어 흡착여재와 여과필터로 많은 연구가 되어온 규조토를 제강 슬래그와 혼합하여 세라믹 여재를 만들고 유기화합물 흡착 특성을 평가하였다. 유기화합물로는 아세틸알데히드, 포름알데히드, 암모니아 기체를 사용하였으며, 각각 80%, 96%, 85%의 흡착 효율을 나타내었다. 사용된 모든 기체에 대해서 80% 이상의 흡착효율을 나타내어 흡착여제로의 활용 가능성을 확인할 수 있었다.