• 한국자동차공학회논문집
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• 제10권2호
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• pp.48-54
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• 2002

Since photocatalysts are activated by lights of UV wavelengths, plasma is alternatively used as a light source for a photocatalytic reactor. Light intensity generated by plasma is proportional to the surface area of catalytic material, and this, in many practical applications, is prescribed by the geometry of a plasma generator. Thus, it is crucial to increase the surface area far sufficient light intensity for photocatalytic reaction. For example, in a pack-bed type reactor, multitudes of beads are used as a substrate in order to increase the surface area. Honeycomb monolith type substrate, which has very good surface area to volume ratio, has been difficult to apply plasma as a light source due to the fact that light penetration depth through the honeycomb monolith was too short to cover sufficient area, thus resulting in poor intensity for photocatalytic reaction. In this study, nonthermal plasma generation through a photocatalytic reactor of honeycomb monolith substrate is investigated to lengthen this short penetration depth. The ceramic honeycomb monolith substrate used in this study has the same length as a three way catalyst used fur automotive applications, and it is shown that sufficient light intensity for photocatalytic reaction can also be obtained with honeycomb monolith type reactor.

• Journal of Plant Biotechnology
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• 제49권4호
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• pp.307-315
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• 2022

개똥쑥은 말라리아 등 다양한 질병의 치료물질인 artemisinin 제공하나, 식물체 내 농도가 낮고, 생산이 불안정하여 국제적 수요에 대응하지 못하고 있다. 재배환경을 인공적으로 제어하는 식물공장 시스템은 계절이나 장소에 제한 없이 약용식물의 공장식 생산체계가 가능하다(Kim 2010). 본 연구에서는 식물공장에서 개똥쑥의 artemisinin의 대량생산이 가능한 최적의 조건을 찾기 위하여 파종부터 수확까지 적색광(R)과 청색광(B)을 혼합한 3종류의 LED (R : B = 6 : 4, 7 : 3, 8 : 2)에서 생장 및 물질생산에 적합한 광조건을 탐색하였다. 개똥쑥의 수확 전, 1,395 ㎼/cm²의 UV-B, 4℃의 저온, 그리고 건조 처리로 식물에 hormesis를 유도하여 artemisinin의 생산 증가를 확인하였다. Artemisinin 생합성에 관여하는 효소들 중에서 ADS, CYP, ALDH1의 발현량을 qPCR로 측정하였고, artemisinin 정량을 통해 전사체와 대사물질의 연관성을 확인하고, artemisinin 생산에 적합한 재배 광조건과 hormesis 처리 조건을 탐색하였다. 3종의 LED 비율 중 8 : 2에서 높은 생체중 및 건물중을 생산했으며, hormesis를 유도하기 위한 3종의 물리 처리에서 이를 통해 7 : 3 식물을 수확전 6시간 건조처리했을 때 artemisinin 함량이 약 2배 증가하였다.

• Advances in Energy Research
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• 제2권1호
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• pp.33-45
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• 2014

Photocatalytic hydrogen generation by water splitting ($H_2O_{(1)}{\rightarrow}H_2_{(g)}+1/2O_2_{(g)}$) has been studied on photocatalysts based on Zn, Cd, Fe and Cu, synthesized by coprecipitation. Iron and copper nanoparticles were incorporated as cocatalysts to enhance the photocatalytic activity of the ZnCd solid solution. The effect of the different synthesis parameters (temperature, elemental atomic ratios, amount of Cu and Fe incorporated in the catalyst and calcination temperature) on the photocatalytic production of hydrogen has been studied in order to determine the best experimental synthesis conditions. The catalysts have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and BET. The experiments of photocatalytic water splitting were performed in aqueous solution of the photocatalysts previously dispersed in a soft ultrasound bath. The photocatalysts were irradiated under different lights ranging from 220 to 700 nm. The photocatalytic activity was found to be clearly dependent on the specific area of the photocatalyst.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2007년도 하계학술대회 논문집 Vol.8
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• pp.108-108
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• 2007

Inkjet printing is a non-contact and direct writing associated with a computer. In the industrial field, there have been many efforts to utilize the inkjet printing as a new way of manufacturing, especially for electronic devices. The etching resist used in this process is an organic polymer which becomes solidified when exposed to ultraviolet lights and has high viscosity of 300 cPs at ambient temperature. A piezoelectric-driven ink jet printhead is used to dispense $20-40\;{\mu}m$ diameter droplets onto the copper substrate to prevent subsequent etching. In this study, factors affecting the pattern formation such as printing resolution, jetting property, adhesion strength, etching and strip mechanism, UV pinning energy have been investigated. As a result, microscale Etch resist patterning of printed circuit board with tens of ${\mu}m$ high have been fabricated.

• 한국응용곤충학회지
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• 제61권4호
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• pp.615-622
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• 2022

본 연구는 콜레마니진디벌의 품질확인장치에 적용할 수 있는 LED 광원을 선발하기 위하여 수행되었다. 4개의 LED 광원(385, 405, 450, 및 660 nm)을 대조구로 5,000k 백색 LED를 사용하여 Y자관 시험에서 선택시험을 수행한 결과, 385 nm LED 광원만 콜레마니진디벌에 대한 유인효과가 있었다. 하지만 3개의 LED 광원(385, 405, 및 450 nm)과 대조구로 5,000k 백색 LED를 사용하여 비선택시험을 수행한 결과, 450 nm > 385 nm > 405 nm 광원 순으로 유인효과가 높았으나 450 nm와 385 nm 광원간 유의차는 없었다. UV-A에 속하는 385 nm LED 광원은 피부질환을 초래할 수 있는 우려가 있어 제외하였고, 최종 450 nm LED 광원을 콜레마니진디벌 품질확인장치에 적용할 광원으로 선발하였다. 450 nm LED 광원을 콜레마니진디벌 우화기구에 적용한 결과, 87.4%의 높은 유인효과를 확인 할 수 있었다. 이러한 결과는 천적 품질관리에 유용하게 활용될 수 있을 것으로 생각된다.