• Proceedings of the Korean Environmental Sciences Society Conference
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• 2005.05a
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• pp.252-254
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• 2005

음용수 처리공법으로 BPA를 분해하는 TiO$_{2}$광분해과정의 생물학적 안전성을 zebrafish(Danio Rerio, wild type)의 발생과 성장기를 통해 알아보았다. TiO$_{2}$ 광분해는 BPA를 제거하는 효과가 있었으며, TiO$_{2}$ 광분해 환경에서 부화된 자어의 경우 배발생 초기와 성장기, 성체시기에 형태적인 이상을 보이지 않았다. 그러나 항산화효소인 catalase 의 활성도는 발생초기와 부화 1, 5주에는 대조군에 비해 별다른 차이가 나타나지 않았으나 28주의 성체기에는 활성도가 절반 이하로 떨어지는 자체방어계의 이상을 보였다.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.04a
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• pp.177-180
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• 2000

In this study, we investigated the pretilt angle generation and liquid crystal (LC) alignment by ultraviolet (UV) exposure during imidization of polyimide on the polymer with side chain. The generated pretilt angle of nematic (N) LC using in-situ photo-alignment method was smaller than that of the conventional UV photo-alignment method. Also, the generated pretilt angle of NLC tends to increase by annealing.

• Journal of Environmental Science International
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• v.15 no.5
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• pp.471-477
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• 2006

We investigated the relationship between the $TiO_2$ photocatalytic decomposition of bisphenol A in water and biological toxicity to zebrafish (Danio rerio) during $1\sim28$ weeks post development stage. The bisphenol A in water was completely degraded by the $TiO_2$ photocatalysis in 50 hours. After the photocatalysis, no toxic effects on the morphogenesis of the zebrafish were observed during the development, growth, and maturate stages. Catalase activity of control group was not different from $1\sim5$ week post fertilized group. However, toxic effect on the catalase activity of adult stage(28 weeks) decreased 50% than control group.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.1
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• pp.75-79
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• 2000

In this study, we investigated the pretilt angle generation and liquid crystal (LC) alignment by ultravi-olet (UV) light irradiation during imidization of polymide. The generated pretilt angle of nematic (N) LC by using the in-situ photo-alignment method was smaller than that of the conventional UV photo-alignment method. Also, generated pretilt angle of NLC tends to increase by annealing. In case of using the polymer(AL-3046), we found that the in-situ Uv photo-alignment method has higher thermal stability of LC alignment, but it has a disadvantage to control pretilt angle.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.13 no.10
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• pp.871-875
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• 2000

Effects of liquid crystal (LC) alignment using a in-situ photoalignment method by polarized UV exposure on a polyimide (PI) surface with medium side chain were studied. The generated pretilt angle in nematic(N) LC using a in-situ photoalignment method was smaller than that of a conventional photoalignment method for short UV exposure time. Also, the pretilt angle of NLC using a in-situ photoalignment method increases with increasing UV exposure time on the PI surfaces. Finally, the pretilt angle of NLC can be improved by annealing treatment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.11a
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• pp.533-536
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• 1999

In this study, we investigated pretilt angle generation and liquid crystal alignment by UV light irradiation during imidization of polyimide. Generated pretilt angle of NLC by using in-situ UV photo-alignment method was smaller than that of the conventional UV photo-alignment method. Also, generated pretilt angle of NLC tends to increase by annealing. We found that in-situ UV photo-alignment method has higher thermal stability of LC alignment, but it has a disadvantage to control pretilt angle.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.336-339
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• 2000

Effects of liquid crystal (LC) alignment using an in-situ photo-alignment method by linearly polarized UV exposure during imidization of polyirnide (PI) on the two kinds of PI surfaces with side chain were investigated. The generated pretilt angle in nematic (N) LC using an in-situ photo-alignment method was smaller than that of a conventional photo-alignment method for short UV exposure time. Also, the pretilt angle of the NLC using an in-situ photo-alignment method increases with increasing UV exposure time on the two kinds of the PI surfaces. Finally, the pretilt angle of NLC can be improved by annealing treatment.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1998.11a
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• pp.343-346
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• 1998

The generation of pretilt angle in nematic liquid crystal (NLC) and electro-optical (EO) characteristics of photo-aligned twisted nematic (TN)-LCD with oblique P-polarized ultraviolet (UV) light irradiation on the two kinds of the soluble polyimide (PI) surfaces containing trifluoromethyl moieties were investigated. The generated pretilt angle of NLC is about 2.5$^{\circ}$with P-polarized UV light irradiation of 20$^{\circ}$on PI-3 surface at 20 min.; However pretilt angle of about 0.5$^{\circ}$are observed on PI-1 and PI-2 surfaces. The generated pretilt angle of NLC on PI-3 surface may be attributed to the trifluoromethyl moieties attached to the lateral benzene rings. The voltage-transmittance and response time characteristics of photo-aligned TN-LCD with P-polarized UV light irradiation of 20$^{\circ}$on PI-1 surface at 20 min were almost same in comparison with the rubbing-aligned TN-LCD. However, the high threshold voltage and slow response are observed on PI-3 surface. Also, the decay time $\tau$$\sub$d/ of photo-aligned TN-LCD is attributed to the anchoring energy of NLC.

• Journal of the Korean Chemical Society
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• v.24 no.5
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• pp.371-379
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• 1980

The spectral properties of the solvated electrons in tetrahydrofuran(THF)-water binary system have been investigated. In this study, the solvated electrons have been produced by applying nsec Q-switch Nd(YAG) laser photolysis technique. The experimental method photolysis were schematically described. The solvent and the temperature effects on the absorption spectrum of solvated electrons have also been studied. The observation of the spectrum with increasing THF content and temperatue showed a trend that the former shifted to longer wavelength and the other showed broadening effect. The half-life of solvated electrons were also increased with THF content. The absorption maxima of the mixtures were always observed in the middle of that of pure water and THF. The correlation between the volume and the absorption energy of solvated electrons were discussed from the results.

• Journal of Korea Soil Environment Society
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• v.1 no.2
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• pp.3-13
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• 1996

The efficiency of bioremedation can be measured by the enumeration of microorganism, respiration rate and decomposition rate. The side-effect can be measured by using Daphnia, oyster larvae and rainbow trout. Oxygen transfer could be a problem in the on-site treatment. For these, hydrogen peroxide can be used for solvents such as benzenes. Oleophilic nitrogen and phosphorus can be added for the treatment of oil pollution. Mixed microbial population or pure culture can be used for the inoculum. The pure culture used is Pseudomonas and Phanerochate. Sometimes enzymes are added and Photodegadation is coupled to increase the efficiency. For the treatment of oil pollution residue on soil such as waste lubrication oil and machine oil sludges, top soil of 15cm∼20cm depth is plowed and oil residue with approximately 5% concentration is applied. The optimum pH range is 7∼8, the ratio of phosphorus to hydrocarbon is 1:800. Appropriate drainage is necessary. For the treatment of marine oil pollution residue, addition of oleophilic fertilizer is effective. Air pollutiant such as oder can be treated by bioremediation. In this case, biofilters or biosrubbers are used for the reactor.