• Journal of Radiation Protection and Research
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• 제33권4호
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• pp.143-150
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• 2008

In this study, we examined the effect of hydroxyl radical generated by $\gamma$-ray and UV irradiation on shrinkage of vitreous body. Change in gel ratio of vitreous body and change in the properties of its components (collagen, sodium hyaluronate) were analyzed. By comparing these results, the amount of hydroxyl radical, which induces the considerable shrinkage of vitreous body, was evaluated from theoretical calculation based on experimental condition and some reported kinetic parameters. It was concluded that the integrated amount of hydroxyl radical required to liquefy half of the vitreous body (Vitreous body gel ratio = 50%) was estimated as $140\;{\mu}molg^{-1}$ from $\gamma$-ray irradiation experiment. Also, from UV irradiation experiment result, it was confirmed that the effect of hydroxyl radical is larger than that of other reactive species. The causes of shrinkage of vitreous body are supposed as follows, 1) decrease in viscosity by cleavage of glycoside bond in sodium hyaluronate, 2) leaching of collagen from vitreous body and 3) leaching of crosslinked products and scission products of collagen.

• 복식문화연구
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• 제11권6호
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• pp.967-971
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• 2003

As the concerns over health increased in 1990's, research and development on the health material were also activated. The development of UV-cut textile became the hot issue, because the damage of W irradiation due to ozone depletion has become widely known. UV-cut effect is determined by the material, the color, the organization and the density of UV-cut fibers. UV-cut effect is very different according to the fibers. Polyester is known to have a better effect. Even in the same textile material, staple fiber has more effect than filament fiber. Different colors have different offsets. Although textiles have the same color, the effects can be different according to the depth of color. PET, PET/cotton blend, nylon and cotton fabrics were ultraviolet cutting finished with padding method using several absorbers. These UV-cut effect can be improved through the processing. Safety of UV-cut textile for the body must be considered future, Until now the figure of the UV-cut effects has been emphasized. There has been no experiment on the human body, although the textiles are directly on the human body. Futhermore there os no safety standard of UV-cut textiles. Therefore every effort will be made to set the standard UV-cut processing is established. The need of UV-cut products will be known to the consumers.

• 한국전기전자재료학회논문지
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• 제16권12호
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• pp.1091-1096
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• 2003

Ion implantation in polymeric materials can induce dramatic chemical modifications, such as bond breaking, cross linking, formation of new chemical products, which have strong influences on the macroscopic properties of the materials. In this study ion implantation was performed onto polymer, PC(polycarbonate), in order to investigate change of the optical transmittance property focusing ultraviolet ray range(200-400nm). PC was irradiated with N, Ar, Kr, Xe ions at the ion energy of 50keV and the dose range of 5 ${\times}$ 10$\^$15/, 1 ${\times}$ 10$\^$16/, 7${\times}$10$\^$16/ ions/$\textrm{cm}^2$. FT-IR, XPS, UV/Vis transmittance spectroscopy measurement technologies were employed to obtain chemical. structural properties and optical transmittance of irradiated polymer. The original PC(unimplanted) is quite transparent that it has more than 88% transmittance in the range UV-A(320∼400nm), but after ion implantation, surface colors were changed to the dark brown and the transmittance of UV ray decreased for all implantation condition, and the absorption edge was shift to visible range with increasing mass of implanted ion species and dose.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2013년도 제45회 하계 정기학술대회 초록집
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• pp.211.1-211.1
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• 2013

We fabricate the conductive zinc oxide(ZnO) thin film using UV-enhanced atomic layer deposition. ZnO is semiconductor with a wide band gap(3.37eV) and transparent in the visible region. ZnO can be deposited with various method, such as metal organic chemical vapour deposition, magnetron sputtering and pulsed laser ablation deposition. In this experiment, ZnO thin films was deposited by atomic layer deposition using diethylzinc (DEZ) and D.I water as precursors with UV irradiation during water dosing. As a function of UV exposure time, the resistivity of ZnO thin films decreased dramatically. We were able to confirm that UV irradiation is one of the effective way to improve conductivity of ZnO thin film. The resistivity was investigated by 4 point probe. Additionally, we confirm the thin film composition is ZnO by X-ray photoelectron spectroscopy. We anticipate that this UV-enhanced ZnO thin film can be applied to electronics or photonic devices as transparent electrode.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2014년도 제46회 동계 정기학술대회 초록집
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• pp.333.2-333.2
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• 2014

RF 스퍼터링 방법을 이용하여 제작된 IGZO 박막 트랜지스터 및 단막을 제조하여 UV처리 유무에 따른 전기적 특성을 평가하였다. IGZO 박막 트랜지스터는 Bottom gate 구조로 제조되었으며 UV처리 이후 전계효과 이동도, 문턱전압 이하 기울기 값등 모든 전기적 특성이 개선된 것을 확인 하였다. 이후 UV처리에 따른 소자의 전기적 특성 개선에 대한 원인을 분석하기위해 물리적, 전기적, 광학적 분석을 실시하였다. XRD분석을 통해 UV처리 유무에 따른 IGZO박막의 물리적 구조 변화를 관찰했지만 IGZO박막은 UV처리 유무에 상관없이 물리적 구조를 갖지 않는 비정질 상태를 보였다. IGZO 박막 트랜지스터의 문턱전압 이하의 기울기 값과을 통하여 반도체 내부에 존재하는 결함의 양을 계산한 결과 UV를 조사하였을 때 결함의 양이 감소하는 결과를 얻었으며 이 결과는 SE를 통해 밴드갭 이하 결함부분을 측정하였을 때와 같은 결과였다. 또한 UV처리 전에는 shallow level defect, deep level defect등의 넓은 준위에서 결함이 발견된 반면 UV처리 이후에는 deep level defect준위는 없어지고 shallow level defect준위 역시 급격하게 감소한 것을 볼 수 있었다. 결과적으로 IGZO 박막의 경우 UV처리를 함에 따라 결함의 양이 감소하여 IGZO박막 트랜지스터의 전계 효과 이동도를 증가 시킬 뿐 아니라 문턱전압 이하 기울기 값을 감소시키는 원인으로 작용하게 된다는 결과를 도출하였다.

• Elastomers and Composites
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• 제37권1호
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• pp.49-56
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• 2002

UV 조사시간과 오존유량을 변화시키면서 폴리프로필렌을 UV/오존 산화하였으며 이의 표면특성을 접촉각과 XPS를 이용하여 살펴보았다. 산화된 표면의 노화거동을 공기, 물, 에틸렌 글리콜 하에서 살펴보았으며, 또한 lap shear 실험을 통하여 접착력을 관찰하였다. 극성표면 에너지와 접착력은 UV/오존 처리시간과 오존유량이 증가함에 따라 증가함을 알 수 있었다. 물에서 노화실험을 한 경우 극성표면 에너지의 변화가 없었으나, 공기 하에서 실시한 경우 2-3일 이내에 급격히 감소하여 처리하지 않은 폴리프로필렌의 값에 근접하였다.

• E2M - 전기 전자와 첨단 소재
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• 제10권1호
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• pp.8-14
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• 1997

The UV/O$_{3}$ dry cleaning has been well known in removing organic molecules. The UV/O$_{3}$ dry cleaning method was performed to clean the Si wafer surfaces and contact holes contaminated by organic molecules such as residual PR. During the cleaning process, the Si surfaces were analyzed with X-ray photoelectron spectroscopy (XPS), atomic force microscope (AFM) and ellipsometer. When the UV/O$_{3}$ dry cleaning at 200'C was performed for 3 minutes, the residual photoresist was almost removed on Si wafer surfaces, but Si surfaces were oxidized. For UV/O$_{3}$ application of contact hole cleaning, the contact string were formed using the equipment of ISRC (Inter-university Semiconductor Research Center). Before Al deposition, UV/O$_{3}$ (at 200.deg. C) dry cleaning was performed for 3 minutes. After metal annealing, the specific contact resistivity was measured. Because UV/O$_{3}$ dry cleaning removed organic contaminants in contact holes, the specific contact resistivity decreased. Each contact hole size was different, but the specific contact resistivities were all much the same. Thus, it is expected that the UV/O$_{3}$ dry cleaning method will be useful method of removal of the organic contaminants at smaller contact hole cleaning.

• 한국안광학회지
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• 제9권1호
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• pp.69-73
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• 2004

${\alpha}-Al_2O_3$ 단결정의 TSEE와 TSL을 $2{\pi}$비례계수기를 사용하여 측정하였다. ${\alpha}-Al_2O_3$ 단결정을 실온에서 500K 온도범위에서 X선과 자외선(UV)을 조사하였다. X선 조사 후에 3개의 TSEE와 3개의 TSL 봉우리가 관찰되었다. ${\alpha}-Al_2O_3$ 단결정의 TSEE와 TSL 그로우곡선은 여기 원의 종류에 관계없이 잘 대용되고 있음을 보여 주었다. 이 연구에서 우리는 $2{\pi}$ 비례계수기가 ${\alpha}$-입자의 에너지 스펙트럼 분석장치 뿐만 아니라 TSEE와 TSL의 측정에도 유익함을 알 수 있었다.

• Elastomers and Composites
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• 제45권1호
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• pp.25-31
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• 2010

우리는 탄소 전구체로 활성탄 (AC), 활성탄 섬유 (ACF)와 탄소나노튜브 (MWCNT)와 티타늄 전구체로써 TNB를 사용하여 탄소-$TiO_2$ 복합체를 제조하였으며, 이들의 특성을 SEM, TEM, BET, XRD와 EDX를 이용하여 분석하였다. 그리고 이들의 광촉매 활성은 UV 램프 조사에서 일정한 농도의 MB 용액을 이용하여 측정하였다. UV 조사한 후에 MB의 농도는 UV-vis 분광광도기를 이용하여 측정하였다.

• Journal of Microbiology and Biotechnology
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• 제12권4호
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• pp.598-602
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• 2002

Damage to cells exposed to radiation is primarily attributed to direct effects on the structure of cellular DNA. Radiation-induced damage of pBluescript SK plasmid DNA and Escherichia coli $DH5\alpha$ were examined in the presence of various branched oligosaccharides, polysaccharides, and/or 8-MOP (8-methoxypsoralen). Branched oligosaccharides efficiently protected DNA and cells exposed to ultrasoft X-ray and UV irradiation. In the presence of 0.2% (w/v) branched oligosaccharides and polysaccharides, DNA can be protected from damage due to W and ultrasoft X-ray by a factor of 1.3-2.1 fo1d and 3.2-8.3 fold, respectively. The protective effect of cells exposed to UV or ultrasoft X-ray was also observed by branched oligosaccharides. The combination of MOP, a photoreagent, with carbohydrates increased the protective effects for DNA and cells, compared with that of a single use of MOP or carbohydrate alone.