• Journal of Photoscience
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• v.10 no.2
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• pp.181-184
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• 2003

Photochemical reactions of some organic molecules on titanium dioxide were investigated in methanol. A methanolic solution of trans-cinnamic acid and titanium dioxide was irradiated with 300 nm UV lamps for 24 h to afford methyl cinnamate. In the case of trans-cinnamamide, the major product was found to be 3-phenylpropionamide, i.e., a saturation product of ethylenic double bond. However, irradiation of urocanic acid, caffeic acid, ethyl cinnamate, trans-chalcone, trans-cinnamonitrile, trans-stilbene or trans, trans-1,4-diphenyl-1,3-butadiene on titanium dioxide under the same conditions did not give any noticeable products. Meanwhile, when irradiated some aromatic aldehydes, such as trans-cinnamaldehyde, l-naphthaldehyde, and 2-naphthaldehyde in methanol, vicinal diols and alcohols derived from the diols were produced. On the other hand, irradiation of 9-anthraldehyde and titanium dioxide in methanol afforded only alcohols, in which diol was not observed.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.1
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• pp.13-23
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• 2003

A local wind model and a three dimensional local environmental model including advection, diffusion, deposition. and photochemical reactions were performed at Gwangyang Bay, Korea, to predict air flow and air pollutants concentrations. A large grid was used, and nesting method was employed for small grid calculation. From the meterological module simulation, we were able to reproduce local wind characteristics such as sea/land winds and mountain/valley winds simulation at Gwangyang Bay. In addition, the concentration module showed high concentration regions at Yosu industrial complex, Gwangyang steel company. and Container anchor. It was also seen that air pollutants were dispersed by sea/land winds. A comparison between the measurement and the prediction of sulfur dioxide and nitric oxide, which are relatively low-reacted pollutants, was performed. However, the measured nitrogen dioxide and ozone concentrations were higher than the simulated ones. Particularly, ozone concentration between 8 a..m. and 8 p.m. agreed well, but the measured ozone during the rest of time were generally higher.

• Journal of Plant Biology
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• v.31 no.3
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• pp.217-226
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• 1988

Effects of simazine [2-chloro-4,6-bis(methylamino)-s-triazine] on the photochemical reactions of isolaed spinach chloroplasts and crude thylakoids of Anabaena inequalis UTEX B-381 were compared. Simazine inhibited photosynthetic O2 evolution and increased the chlorophyll fluorescence in whole cells of Anabaena. The electron transfer from diphenylcarbazide to 2,6-dichlorophenolindophenol was inhibited by simazine treatment in spinach chloroplasts, but not in crude thylakoids of Anabaena. In spinach chloroplasts, the chlorophyll fluorescence was increased by simazine treatment in the presence of diphenylcarbazide and ferricyanide, but not in the presence of diphenylcarbazide and silicomolybdate. In crude thylakoids of Anabaena, simazine treatment did not increase the chlorophyll fluorescence in the presence of either diphenylcarbazide and silicomolybdate, or diphenylcarbazide and ferricyanide. There results suggest that the inhibitory site of simazine on photosynthetic electron transport chain of anabaena is different from that of spinach chloroplasts. And there may be a possiblity that the inhibition site of simazine in Anabaena lies on the donor side of photosystem II, before the site of electron donation by diphenylcarbazide.

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2003.11a
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• pp.239-240
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• 2003

스모그 챔버는 대기 중 성분들의 화학 반응 기작을 연구하는데 사용되고 있다. 그러나, 기존 연구에서는 광화학 반응 전구물질의 농도가 실제 대기 농도보다 높고, 청정 공기에 연구 대상 전구물질만을 주입한 단순 혼합물을 이용하였으며, 여러 날에 걸쳐 반응이 진행된 성분들을 이용하지 않았다 (Dodge, 2000). 이와 달리 본 연구팀에서는 실내 스모그 챔버에 실제 대기를 도입하여 광화학 반응 실험을 수행하고 있다 (배귀남 등, 2003). 한 개의 스모그 챔버를 이용하는 경우 외기의 특성상 매 실험마다 초기조건이 달라지기 때문에 단일 인자의 차이에 따른 영향을 파악하기가 쉽지 않았다 (배귀남 등, 2003b). (중략)

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2002.04a
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• pp.171-172
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• 2002

대기중의 2차 광화학 반응을 포함하는 대기중의 반응을 이해하고 해석하기 위하여 Smog Chamber를 이용한 대기중 광화학 반응연구가 활발히 진행 중에 있으며, 국내에서도 연구가 이루어지고 있다 이러한 연구들은 고농도 수준에서 광화학 반응 메커니즘에 중점을 두고 있는 것으로 실제 대기의 농도수준에서 광화학반응에 관한 연구자료는 미흡한 실정이다. 또한, 서울지역의 경우 광화학 스모그의 대표적인 경우에 해당하는 LA Smog의 경우와 비교할 때 습도가 높으며, 대기 중 먼지의 농도 또한 비교적 높다고 볼 수 있으며 이러한 서울지역의 광화학 스모그 특성을 규명하기 위하여 기초연구라 할 수 있는 Smog Chamber 연구가 필요하다. (중략)

• Proceedings of the KSR Conference
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• 2002.10b
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• pp.943-947
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• 2002

Volatile Organic Compounds(VOCs) contribute to the formation of ozone and PAN which are injurious to health through complex photochemical reactions. Growing consumption of fossil fuels results in significant emission of VOCs and other air pollutants into the atmosphere. This study was carried out to evaluate of Volatile Organic Compounds(VOCs) concentrations in Kumi industrial complex. Ambient air sampling was determined at five sites from August to September in 2002. The Volatile Organic Compounds samples were collected using the silicocan canisters, and were determined by GC/MS which connected preconcentrator system. The Kumi industrial complex of VOCs concentrations were generally similar with Yeochun's but some of VOCs concentrations of Kumi were higher than Yeochun industrial complex's. Also the industrial area was higher than downtown and residential district.

• Journal of the Korean Chemical Society
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• v.26 no.2
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• pp.99-106
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• 1982

The ketone chromophore of 1-Acetyl-1-methyl-2-cyclopentene (1) was replaced by nitrile, carboxylic acid and acetamide group, and their photochemical reactions were investigated. While the ${\beta},\;{\gamma}$-unsaturated ketone 1 afforded 1,2 ar 1,3-Acyl shift product, these replaced chromophores did not afford any monomeric rearranged products. 1-Cyano-1-methyl-2-cyclohexene also afforded no product anology of the 1,2-acyl shift reaction. The replacement of the ketone chromophore by nitrile, carboxylic acid and carboxamide has greatly altered the photochemistry of ${\beta},\;{\gamma}$-unsaturated ketones.

• Journal of the Korean Chemical Society
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• v.34 no.6
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• pp.600-605
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• 1990

Electron injection from excited rose bengal into the conduction band of a thin film of SnO$2$, semiconductor was investigated in an electrochemical cell, ITO/SnO$2$/rose bengal, NaClO$4$/Pt. It was observed that urea enhanced the supersensitized photocurrent, followed by the reduction in the photocurrent after a shallow maximum. Spectroscopic analyses of the dye solution containing urea revealed that dye aggregation appeared to be involved in the increased photocurrent, although the concentration of the dye was continuously decreased dye to photochemical reactions.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.572-576
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• 2002

Volatile Organic Compounds(VOCs) contribute to the formation of ozone and PAN which are injurious to health through complex photochemical reactions. Growing consumption of fossil fuels results in significant emission of VOCs and other air pollutants into the atmosphere. In this study, Ambient an grab samples of VOCs were collected at the platform and the concourse of six stations in the subway from February 21th to 28th. Among the total contents, Toluene (118.74 ppm) showed the highest concentration in the Indukwon station platform while other contents were measured low concentrations. Also, the platform concentrations were higher than the concourse concentrations through the whole contents.

• The Journal of Natural Sciences
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• v.5 no.1
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• pp.59-65
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• 1992

In this study, new photosensitive polymers bearing acyloxyimino(AOI) group were prepared and the relationship between photochemical reactions of the polymers and changes of their physical properties was investigated. It was found that main reaction of these copolymers depended on the structure of polymer mainchain. From the view point of amino groups formation, acryl type polymers were superior to methacryl type polymers. On the other hand, in the case of mathacryl type polymers, mainchain scissions and formation of double bonds occurred very effectively. Applications of these copolymers to photofunctional polymers were also discussed.