• 한국세라믹학회지
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• 제43권3호
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• pp.185-192
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• 2006

The effects of annealing on structural and electrical properties of ITO/PES (Indium Tin Oxide/Polyethersulfone) films was investigated. Amorphous ITO thin films were grown on plastic substrates, PES using low temperature DC magnetron sputtering. Various post annealing techniques were attempted to research variations of microstructure and electrical properties: i) conventional thermal annealing, ii) excimer laser annealing, iii) UV irradiation. The electrical properties were obtained using Hall effect measurements and DC 4-point resistance measurement. The microstructural features were characterized by FESEM, XRD, Raman spectroscopy in terms of morphology and crystallinity. Optimized UV treatment exhibits the enhanced conductivity and crystallinity, compared to those of conventional thermal annealing.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 춘계학술대회 논문집 디스플레이 광소자분야
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• pp.210-213
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• 2004

We synthesized photoalignment material of high thermal resistance with hydroxyl aromatic polyimide, and studied the liquid crystal (LC) aligning capabilities on the photopolymer layers. Also, electro-optical (EO) performances for the twisted-nematic (TN)-liquid crystal display (LCD) photoaligned with linearly polarized UV exposure were investigated. A good LC alignment with UV exposure on the photopolymer surface can be obtained. However, the low pretilt angles were obtained below $1^{\circ}$. The Voltage-transmittance (V-T) curve without backflow bounce in the photoaligned TN cell with UV exposure was observed. The response time of photoaligned TN cell was measured about 24 ms. Finally, The photoaligned TN cell has few hysteresis, and shows the residual DC voltage that is less.

• 한국동물생명공학회지
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• 제34권1호
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• pp.20-29
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• 2019

Soy isoflavones have been reported to possess many physiological activities such as antioxidant activity and inhibition of cancer cell proliferation. This study investigated the photoprotective effects of soybean extract in human fibroblast cell line and hairless mice model. Human fibroblast was treated with soybean extract before and after ultraviolet B (UVB; 290-302 nm) irradiation. In the soybean extract treated group, the cells showed better resistance to ultraviolet (UV) than control group. The amount of type I collagen recovered from the soybean treated group was higher than the vehicle group exposed to UV-induced damage. Moreover, increased expression of metalloproteinases-1 as a result of UV irradiation was suppressed by the soybean extract. Female mice were orally administered soybean extract and irradiated with UVB light for 8 weeks. The effects of the soybean extract on the skin appearance, collagen deposition and epidermal thickness in the UV-damaged mouse skin were analyzed using histopathological methods. In soybean extract treated group, the skin had a better morphology than that of the control group. Furthermore, the amount of type I collagen was increased and overexpression of MMP-1 was reduced in the soybean extract group compared to vehicle group. Additionally, up-regulation of pro-inflammatory cytokines induced by UV irradiation was suppressed by dietary soybean extract treatment. It appears that soybean extract had a photoprotective effect, including anti-aging and anti-inflammatory effect, from UV-induced damage in not only human fibroblast, but also hairless mice. We confirmed that these effects were possibly due to promotion of collagen synthesis and inhibition of MMP-1 expression.

• 미생물학회지
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• 제26권2호
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• pp.113-121
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• 1988

Ozone, an atmospheric pollutant, can damage similar UV and X-rays DNA and its components. It is possible then that the KNA damage produced by this gas are similar, to some extent, to those of radiations and that they could be repaired by the same DNA repair mechanisms. It has been observed in Escherichia coli that radiosensitive strains such as lex A, rec A and pol A, all deficient to some extent for DNA repair, are more sensitive to ozone than a wild type strain. We have thendetermined the ozone resistance and host-cell reactivation of ozone-damaged T3 phages for the E. coli double mutants pol A, lex A, uvr B, lex A, uvr A, rec A and rec A lox A. According to the results, the DNA polymerase 1 plays a key role in ozone resistance and Type 11 mechanism and/or shory patch excision repair are the most important for it. The interactions between the different DNA repair mechanisms are secondary. There is a strong correlation between ozone resistance and the capacity to reactivate T3 phages damaged by ozone.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1997년도 하계학술대회 논문집 E
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• pp.1813-1815
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• 1997

In this study, in order to develop outdoor insulating materials, SIN(simultaneous interpenetrating polymer network) was introduced to Epoxy resin and the environment resistance was investigated. Six kinds of specimen were manufacture by filler($SiO_2$) content. SEM was untilized in order to confirm their network structure changes. Also, tracking test, UV test and acid rain test were carried out investigate the environment resistance characteristic. Therefore it was confirmed that simultaneous interpenetrating polymer network specimens were more excellent than single network structure specimens. But, acid rain almost never changed resistance.

• 미생물학회지
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• 제28권2호
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• pp.109-113
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• 1990

Mutator 기능을 가지는 플라스미드 pKM101과 이의 돌연변이체 pSL4를 DNA 수복능력이 다른 Esherichia coli B/r(phr, recA, uvrA, uvrB)균주들에 도입하여 돌연변이원인 UV와 MNNG에 대한 보호효과와 mutagenecity를 조사형ㅅ다. pKM101과 pLS4의 mutator 기능과 보호효과는 repair 기능에 따라 다르나 전반적으로 두 플라스미드의 UV와 MNNG에 대한 저향성과 돌연변이율을 증가시켰고 pLS4는 pKM101보다 그효과가 높았다. 이러한 pLS4와 pKM101의 기능적 차이는 이들 플라스미드의 mutator 유전자상에 일어난 변이에 의한 것이라고 생각되었다.

• 공업화학
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• 제16권1호
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• pp.101-106
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• 2005

Dipentaerythritol 유도체(DPET)와 acrylic acid를 반응하여 6관능 광경화형 변성 폴리아크릴레이트(PA-1)를 제조하였으며, dipentaerythritol 유도체(DPET)에 trimellitic anhydride와 glycidyl methacrylate를 반응시켜 12관능 광경화형 변성 폴리메타아크릴레이트(PA-2)를 제조하고 경화된 물성을 조사하였다. 관능기 수가 증가할수록 중량 평균 분자량은 증가하였으며, TGA (Thermogravimetric Analyzer)로 측정한 UV 경화필름의 열안정성은 (메타)아크릴레이트의 관능기 수가 많을수록 증가하였다. 또한 (메타)아크릴레이트의 관능기 수가 많을수록 경도, 내마모성, 인장강도가 우수하였으며, 내후성 테스트에서는 (메타)아크릴레이트의 관능기 수가 많을수록 황변 지수 값인 yellow index 값이 높아지는 결과를 보여주었다.

• Journal of the Korean Wood Science and Technology
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• 제49권5호
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• pp.471-481
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• 2021

This study investigated the hygroscopicity and UV deterioration characteristics of 3 domestic and 4 imported woods using natural oil, stain, and varnish paints. In terms of hygroscopicity, it was found that the hygroscopicity of the painted wood was lower than that of the unpainted wood, and that as the number of coatings increased, the hygroscopicity decreased. In terms of anti-absorption, oil-based chemical paints showed higher resistance than water-based paints, and natural oils showed results comparable to oil-based paints. As for the UV deterioration, the amount of color change of the painted wood was lower than that of the unpainted wood, and there was no significant difference according to the number of times of painting. The amount of color change was found to be low in oil-based paints and hardwoods. Through this study, we confirmed effective moisture blocking and small color changes during painting using paints, and it is believed that wood can be protected from internal and external defects through selective and efficient painting based on data for excellent painting performance.

• 한국염색가공학회지
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• 제35권4호
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• pp.231-238
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• 2023

Microporous gel films of 29 m were prepared by the gel drawing of UHMWPE/soybean oil blend (4:6, w/w) up to 800%. The stretched films containing the optimal photoinitiator concentration, depending on the film thickness, was cross-linked under 365 nm LED-UV irradiation and the oil was extracted with n-hexane, resulting in a gel fraction of 95 % or more. With the formation of the cross-linked structure, the melt-down temperature and melt-down elongation increased by 16 ℃ and by 63% respectively. Also the thermal stability of the crosslinked UHMWPE was proved by the area shrinkage under the heat treatment decreased to 3.8 % compared to 17.4 % for the pristine film, and by the reductions in the combustion heat. The enhanced thermal stability of the crosslinked UHMWPE microporous membranes can be used for various industrial applications such as filters, electric vehicles and energy storage systems.

• 한국산학기술학회논문지
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• 제21권12호
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• pp.23-32
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• 2020

본 연구는 PTT에 vat 염료의 염색성을 살펴보고, vat 염료로 염색된 PTT의 취화거동 및 퇴색거동을 연구하였다. PTT 소재에 vat 염료의 염착을 개선하기 위하여 pad-steam 법을 응용하였으며, 염색 중에 산 처리 효과를 살펴보았다. 염색 과정에서 산 처리는 vat 염료의 입자 크기를 작게 만들어 소재 내부 침투를 용이하게 하고 염료의 과환원을 방지하여 염색성을 향상시켰다. 여기에 pad-steam 염색법은 일반적인 침염법보다 염료의낯 고착성을 증가시켜 균염을 개선하였다. Vat 염료로 염색된 PTT의 취화와 퇴색거동은 열과 자외선에 일정시간 동안 노출시킨 후 인장강도와 K/S 값으로 분석하였다. 열과 자외선의 온도가 올라갈수록, 또 노출 시간이 증가할수록 시료의 인장강도 저하되었으나, 이러한 취화 속도는 산화방지제와 함께 분산염료로 염색된 시료보다 더 느리게 나타나서 향상된 거동을 보였다. 퇴색거동 역시 vat 염료로 염색된 시료가 자외선흡수제가 포함되고 분산염료로 염색된 시료보다 훨씬 뛰어난 특징을 나타냈다. 결과적으로 vat 염료는 pad-steam 법으로 PTT 소재에 효과적으로 적용시킬 수 있으며, 이때의 내열성과 내광성은 우수하게 나타났다.