• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2003.05b
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• pp.144-148
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• 2003

알루미나볼 위에 Titanium tetraisopropoxide(TTIP)를 원료로, 화학기상증착법으로 제조된 $TiO_{2}/Al_{2}O_{3}$ 볼을 이용하여 벤젠의 기상 광 분해 실험을 실시하였다. 기상분해 과정의 연속적 측정을 위하여 순환식의 반응장치를 자체 제작하였으며, PID(Photo Ionization Detector)방식의 VOCs meter를 이용하여 광조사에 의한 벤젠의 분해율을 실시간으로 측정하였다. 기상의 벤젠과 $TiO_2/Al_{2}O_{3}$ 볼의 원활한 흡착을 위해 30분간 암반응 시킨 후 광분해율을 측정한 결과 광조사에 의한 분말표면에 흡착된 VOCs의 탈착에 의한 초기 농도증가 현상이 공통적으로 측정되었으며, 흡착 면적이 작을수록 농도 증가 또한 낮게 측정되었다. 또한 최적조건을 기준으로 실시한 분해 실험 결과 60ppm이상의 고농도 영역에서는 VOCs의 분해가 비교적 느리게 진행되었지만, 60ppm이하의 저농도 영역에서는 급속한 VOCs의 분해가 측정되었다. 마찬가지로 반응 표면적이 넓을수록, 광원이 많을수록 그리고 광분해에 사용된 자외선 램프의 강도가 클수록 광반응에 의한 벤젠의 분해율이 증가하였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.495-498
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• 2000

In this paper, generation form of displacement current was compared and measured with air-water interfacing induce monolayers which 8A5H with azobenzene and arac.acid mixed. Light response of two monolayers which chain length are different was compared and measured though they are the same isomer. The experimental results are as following; In the displacement current form of mixed monolayers and 8A5H, mixed monolayers which chain length is longer than that of 8A5H caused the displacement current about 40[fA] mole. This is the reason chain length of hydrophobicity in mixed monolayers is longer than that of 8A5H In the case of light stimulus mixed monolayers reacted less than 8A5H about 9[fA]. This is the reason molecule dynamic behaviour in cia and trans was net activated due to its very long chain length.

• Textile Coloration and Finishing
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• v.2 no.2
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• pp.43-50
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• 1990

색을 가지는 물질 즉 "색소" 란 인간의 눈에 시각으로서의 색을 인식 시키는 물질이다. 따라서 색소는 대상을 colorful하게 만들며 생활을 풍요롭게 하는데 필수불가결한 물질이다. 합성염료가 개발되기 이전부터 인간은 동물, 식물, 광물에서 색소를 추출해 사용해 왔다. 그러나 색소의 "색" 이외의 물성을 적극적으로 이용 할려고는 하지 않았다. 색소가 가지는 특성과 기능은 광흡수(색, 근적외 흡수, 다색성), 광방사(형광, 인광), 광 전도성, 가역변화(열, 광, pH), 화학 반응성 등이며, 이들의 특성과 기능이 색소를 광과 전자 분야에 관련되는 재료로 응용되게 유도 하였다.련되는 재료로 응용되게 유도 하였다.

• Journal of the Korean Ceramic Society
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• v.39 no.6
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• pp.535-539
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• 2002

In this study photoadsorption propreties of Ag ion in AgNO$_3$ solution by TiO$_2$nanopowder synthesized by homogeneous precipitation process at low temperature were investigated. It was found that the photocatalytic redliction in AgNO$_3$solution was occurred by TiO$_2$nanopowder even under th sun light irradiation, although the reduction of Ag ions was slow with th small adsorption of 9.32 ppm. Notably the Ag adsorption was promoted in th dark condition probably owing to the chestnut bur shape of TiO$_2$ nanopowder itself. In the application of UV the Ag ions were completely adsorbed within 120 min, showing more significant photocatalytic reaction. The measured adsorption reaction rate and adsorption equilibrium rate constants were 0.0004 g/min and 1494.20(120 $m^2$/g), respectively.

• KSBB Journal
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• v.18 no.4
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• pp.277-281
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• 2003

The study of growth characteristics for Spirulina platensis were carried out in 400 mL cylindrical photobioreactor and the effects of carbon dioxide concentration and flow rate during the growth of Spirulina platensis were investigated. The results showed that relatively low carbon dioxide concentration and high flow rate forced the growth of Spirulina platensis in experiment conditions. The pH analysis showed that different carbon dioxide concentration might form particular aqueous carbonate system in culture medium and affect the growth of Spirulina platensis. In addition, the possibility of limiting light radiation by cell density was investigated by the analysis of specific growth rate. The result intimated that the cause of decrease of specific growth rate at exponential phase was due to the limitation of light radiation by Spirulina platensis cell density in cylindrical photobioreactor.

• Journal of the Korean Chemical Society
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• v.42 no.2
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• pp.203-208
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• 1998

The photochemical reactivities of 2-halobenzyl phenyl ether, in which 2-halobenzyl moiety are tethered to phenyl moiety by the etheral alkyl linkage, has been studied. In the presence of nitrogen, the photochemical reaction of 2-chlorobenzyl phenyl ether (1) produces mainly phenol and photo-Fries type reaction products, while the corresponding bromo analog 2 produces photocyclization and photoreduced products, along with phenol and photo-Fries type products. The former result implies that since chlorine is bound to the benzyl ring firmly, the rather weaker $CH_{2}-O$ bond of 1 is cleavaged to produce the photo-Fries type product. The latter implies that the photoinduced fission of phenyl-bromine bond of 2 can compete with the fission of $CH_{2}-O$ bond, since the bond energy of phenyl-bromine is lower than that of phenyl-chlorine. Since by the presence of oxygen the formation of phenol is not affected much, the formation of photo-Fries type products is changed a little, and the formations of photocyclization and photoreduced products are affected effectively, a singlet state is involved in the formation of phenol, and both singlet and triplet state may be involved in the formation of photo-Fries type reaction, while a triplet state is involved in the formation of photocyclization and photoreduction products.

• Applied Chemistry for Engineering
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• v.10 no.1
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• pp.124-128
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• 1999

The photochemistry of the derivatives of o-nitrobenzylcarboxyl esters or benzylsulfonyl derivatives has been well studied separately. But little attempt has been made to combine the fruits these two studies. Being photochemically active, benzylsulphonyl and intro groups should influence the reactivity of each other's, especially when the excited states are fully mixed due to the proximity of their location. The questions which should be clearly answered are; what kind of effect will be excerted to the other group, and whether these two functional groups are coupled in the course of the reaction. To answer the questions raised above, wer have synthesized two sulfonyl esters and four amides from the newly available starting material, 2-nitro-${\alpha}$-toluenesulfonyl chloride. The products identified from the exploratory solution photochemistry were cyclohexanol, phenol, cyclohexylamine, and sulfur dioxide. The results are not much different from the products originally anticipated. It has been temporarily concluded that there is little interaction between the benzyl sulfonyl group and ortho-nitro chromophore. The fact that a base (an amine) has been photochemically generated in solution photochemistry was further confirmed by and utilized in the solid phase quantitative photochemistry done on the film, so as to carry out the photochemical epoxide cure.

• Journal of Bio-Environment Control
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• v.4 no.2
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• pp.125-130
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• 1995

Observations on the seedling growth of red pepper responding to different temperature(10, 20, 3$0^{\circ}C$) and light intensity(5, 15, 25 klux) were made in the growth Chamber during 7 weeks. The results obtained were as follows; 1. Best results of the combinations of temperature and light intensity were obtained from the combinated treatment of 3$0^{\circ}C$ and 25klux. At all of the temperature levels in this experiment, the more the light intensity is high, the more the growth is favor, but at low temperature below 2$0^{\circ}C$ and low light intensity below 15 klux, the growth of red pepper seedlings was decreased markedly. 2. Multiple regression polynomial equations of the characteristics of red pepper seedlings grown in the different combinations of temperature and light intensity fitted well in the plant height, number of leaves, leaf area, stem dry weight and shoot dry weight. 3. Multiple regression polynomial equation to the shoot dry weight was partial differentiated and diagrammatized the response surface using its theoretical value. Light intensity affected more to the shoot dry weight in the temperature below 2$0^{\circ}C$ but above 2$0^{\circ}C$ the role of the temperature showed greatly influence however, interaction effects of light intensity and temperature showed strongly.

• Korean Journal of Ecology and Environment
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• v.53 no.1
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• pp.102-108
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• 2020

This study is to analyze the growth response of the Quercus dentata seedlings to four environmental factors and measure the ecological niche breadth. Environmental factors were light, moisture content, soil texture, and organic matter, treated with four gradients. The more quantity light increased, the heavier the leaves biomass, aboveground biomass, belowground biomass and plant biomass was. In treatment of water content and soil texture, growth response was no difference. The more organic matter increased, the heavier aboveground biomass was, but the remaining trait of plant was no difference. The ecological niche breadth was 0.865 in light, 0.995 in moisture content, 0.994 in soil texture and 0.988 in nutrient. Ecological niche breadth was the widest in the moisture content treatment and the narrowest in the light treatment. This means that the growth of Q. dentata seedlings grows well as the amount of light increases, and is sensitive to light, Thus, it is determined a growth and ecological niche breadth by light factors.

• Polymer(Korea)
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• v.35 no.5
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• pp.493-498
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• 2011

Reactive mesogens were used to prepare photo-cured liquid crystal films in which orientations of liquid crystal molecules were preserved by crosslinked networks of cured reactive mesogens. The molecular orientations of liquid crystal mixtures of photo-reative mesogens and non-reactive nematic liquid crystals were studied and compared before and after curing reactions. The effects of temperature and the amount of the non-reactive nematic liquid crystal in the mixture on birefringence of the liquid crystal films were investigated. It was found that optical compensation films with different birefringence could be prepared by controlling the amount of the nematic liquid crystals in the reactive mesogen mixtures.