• 청정기술
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• 제16권1호
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• pp.46-50
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• 2010

본 연구에서는 새집증후군의 대표적 원인물질인 수중 부유 톨루엔을 효율적으로 분해하기 위해 Sn원소를 티타니아 골격에 삽입하여 고온 고압에서 용매열(solvothermal)법으로 Sn-$TiO_2$ 나노 광촉매를 제조하였다. 제조한 Sn-$TiO_2$의 물리적 특성은 X-ray 회절분석법, 투과전자현미경, 주사전자현미경, 자외선-가시선 분광 광도계를 통하여 분석하였다. Sn-$TiO_2$의 광촉매 활성은 수중 부유 톨루엔 광분해반응을 통해 확인하였고, 반응 전후의 수중 부유 톨루엔 농도는 자외선-가시선 분광광도계를 이용하여 측정하였다. 수중 부유 톨루엔 광분해반응 결과 0.01 mol% Sn-$TiO_2$촉매가 순수 $TiO_2$ (anatase) 광촉매보다 활성이 향상되었으며. 500ppm 수중 부유 톨루엔은 300분 이내에 완전히 분해되었다.

• 한국진공학회지
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• 제18권5호
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• pp.358-364
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• 2009

펄스레이저 증착법으로 박막의 결함 생성을 최소화하여 우수한 발광 특성을 가지는 ZnO 박막 성장에 대한 연구를 수행하였다. 이를 위하여 기판 온도를 $400^{\circ}C$에서 $850^{\circ}C$까지 변화시켜 박막을 증착한 후 엑스선 회절법, 원자힘 현미경, photoluminescence (PL) 등을 사용하여 박막의 특성 변화를 분석하였다. 그 결과 ZnO 박막은 기판 온도에 관계없이 (0001) 사파이어 기판에 c-축 배향성을 가지며 성장하였음을 확인하였고 기판온도 $600^{\circ}C$에서 가장 조밀한 박막이 형성되면서 박막에 응력이 거의 걸리지 않고 결정성도 우수함을 확인하였다. PL 분석 결과 역시 $600^{\circ}C$에서 증착된 ZnO 박막이 UV 발광 피크의 반치폭 및 결함에 의한 가시영역에서의 발광 등을 고려했을 때 가장 뛰어난 특성을 보여주었다. 이와 같은 결과는 ZnO 박막의 발광 특성이 박막의 구조적 특성과 매우 밀접한 관계가 있음을 나타내며 또한 기판 온도가 매우 중요한 역할을 함을 나타낸다. 결론적으로 기판 온도 $600^{\circ}C$에서 우수한 UV 발광 특성을 가지면서 결함에 의한 가시영역 발광이 거의 나타나지 않는 ZnO 박막을 성장시킬 수 있었고 이러한 박막은 UV 광소자에 응용될 수 있을 것으로 생각된다.

• 폴리머
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• 제38권6호
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• pp.827-831
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• 2014

라디칼 고분자화 반응 후 산화법을 이용하여 나이트록실 라디칼 고분자를 제조하였다. 두 가지 방법으로 산화된 라디칼 고분자의 라디칼 농도를 electroparamagnetic resonance spectroscopy(EPR) 법과 UV-visible absorption (UV-vis) 방법을 통하여 측정하고 이를 통해 과산화수소수-$Na_2WO_4$ 법으로 산화하였을 때 라디칼 농도가 97.6% 정도 높게 얻어짐을 확인하였다. 또한 UV-vis 법은 정량적인 분석이 어려우나 대략적인 라디칼 형성 정도를 평가하는데 유용함을 확인하였다. 제조된 유기라디칼 고분를 리튬이온전지 양극재로 적용한 결과 우수한 용량, 초기효율, 높은 속도 특성을 가짐을 알수 있었다.

• 한국진공학회:학술대회논문집
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• 한국진공학회 2016년도 제50회 동계 정기학술대회 초록집
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• pp.390.2-390.2
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• 2016

Single crystalline indium-tin-oxide (ITO) nanowires (NWs) were grown by sputtering method. A thin Ni film of 5 nm was coated before ITO sputtering. Thermal treatment forms Ni nanoparticles, which act as templates to diffuse Ni into the sputtered ITO layer to grow single crystalline ITO NWs. Highly optical transparent photoelectric devices were realized by using a transparent metal-oxide semiconductor heterojunction by combining of p-type NiO and n-type ZnO. A functional template of ITO nanowires was applied to this transparent heterojunction device to enlarge the light-reactive surface. The ITO NWs/n-ZnO/p-NiO heterojunction device provided a significant high rectification ratio of 275 with a considerably low reverse saturation current of 0.2 nA. The optical transparency was about 80% for visible wavelengths, however showed an excellent blocking UV light. The nanostructured transparent heterojunction devices were applied for UV photodetectors to show ultra fast photoresponses with a rise time of 8.3 mS and a fall time of 20 ms, respectively. We suggest this transparent and super-performing UV responser can practically applied in transparent electronics and smart window applications.

• Asian Journal of Atmospheric Environment
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• 제5권2호
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• pp.79-85
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• 2011

The purpose of this study is to evaluate the strength of the near-UV wavelength of 380 nm relative to visible and near-IR bands, and to find the suitable wavelength for detecting aerosols by using the Global Imager (GLI) sensor aboard the Advanced Earth Observing Satellite-II (ADEOS-II). Sensitivity analysis is performed for the retrieval of biomass burning aerosols by employing the radiative transfer model Rstar5b. It is determined that background surface reflectance in the blue band is similar to that in the near-UV band, and that wavelengths in the blue bands are more sensitive to the Aerosol Optical Thickness (AOT) than wavelengths in the near-UV band. The Total Ozone Mapping Spectrometer (TOMS) Aerosol Index (AI) is used in the indirect method used for aerosol retrieval, and the wavelength pair 380 nm and 460 nm is determined to be the most sensitive to the AOT. The results of this study suggest that wavelengths in the blue bands are suitable for detecting biomass burning aerosols over the Korean peninsula.

• 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.

• 한국생활과학회지
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• 제10권3호
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• pp.263-274
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• 2001

This study investigated the dyeability on silk, wool and rotten fabrics dyed with Magnolia liliflora leafs. In addition, the fastness of washing, perspiration, rubbing, drycleaning and the effects of its pigment on bacterial reduction and uv-B protection were also investigated. The results were as follows : It was found that uv-visible absorption spectrum showed two strong absorption peaks in the range of $250{\sim}340nm$. The optimum dyeing condition of the pigments extracted from the Magnolia liliflora leafs was dyeing with 0.5% mordants and three repeated dyeing at $95^{\circ}C$ for 1hr. When the wool fabric was dyed with Magnolia liliflora leaf, dyeing properties was the best among the three fabrics. Washing fastness of dyed fabrics was very low, drycleaning fastness was good and the other fastness were good. Light fastness of three fabrics dyed by Magnolia liliflora leafs increased by mordant treatment, especially copper sulfate treatment. The bacterial reduction and uv-B protection of dyed wool fabric with Magnolia liliflora leafs also increased.

• Journal of Biosystems Engineering
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• 제35권2호
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• pp.124-131
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• 2010

Chlorophyll fluorescence has been researched for assessing fruit post-harvest quality and condition. The objective of this preliminary research was to investigate the potential of fluorescence spectroscopy for measuring apple fruit quality. Ultraviolet (UV) and blue light was used as an excitation source for inducing fluorescence in apples. Fluorescence spectra were measured from 'Golden Delicious' (GD) and 'Red Delicious' (RD) apples using a visible/near-infrared spectrometer after one, three, and five minutes of continuous UV/blue light illumination. Standard destructive tests were performed to measure fruit firmness, skin and flesh color, soluble solids and acid content from the apples. Calibration models for each of the three illumination time periods were developed to predict fruit quality indexes. The results showed that fluorescence emission decreased steadily during the first three minutes of UV/blue light illumination and was stable within five minutes. The differences were minimal in the model prediction results based on fluorescence data at one, three or five minutes of illumination. Overall, better predictions were obtained for apple skin chroma and hue and flesh hue with values for the correlation coefficient of validation between 0.80 and 0.90 for both GD and RD. Relatively poor predictions were obtained for fruit firmness, soluble solids content, titrational acid, and flesh chroma. This research has demonstrated that fluorescence spectroscopy is potentially useful for assessing selected quality attributes of apple fruit and further research is needed to improve fluorescence measurements so that better predictions of fruit quality can be achieved.

• 한국분말재료학회지
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• 제11권2호
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• pp.143-148
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• 2004

In the present study, $TiO_2$ imbedded composite powders have been successfully prepared from the (Cu. Zn)/$TiO_2$ composite salt solution. The composite (Cu, Zn)/$TiO_2$ powders were formed by drying the solution at 200~$600^{\circ}C$ in the hydrogen atmosphere. Photocatalytic characteristics was evaluated by detecting the decomposition ratio of aniline blue with UV-visible spectrophotometer(Shimazu Co., UV-1601). Phase analysis of (Cu, Zn)/$TiO_2$ composite powders was carried out by XRD and DSC, and powder size was measured with TEM. The mean particle size of composite powders was about 100mm. As the reduction temperature increases, a few zinc sulfide and oxide phases was formed and copper oxide phase was reduced. The decomposition ratio of aniline blue was about 80％ under the UV irradiation by the TiO$_2$ phase in the composite (Cu, Zn)/$TiO_2$ powders and similar decomposition ratio of 80％ was obtained at the UV lightless condition by virtue of Cu and Zn compounds.

• 통합자연과학논문집
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• 제9권1호
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• pp.16-22
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• 2016

The optical and physical and characteristics of hydrogel ophthalmic lens polymerized with addition of 2,6-difluoropyridine, SiPc(silicon 2,9,16,23-tetra-tert-butyl-29H31H-phthalocyanine dihydroxide) and nanodiamond in the basic hydrogel material were evaluated. In particular, the utility of 2,6-difluoropyridine, SiPc and nanodiamond as a hydrogel ophthalmic lens material was investigated. 2,6-difluoropyridine, SiPc and nanodiamond were used as additives. And also, 2-hydroxyethyl methacrylate, acrylic acid, methyl methacrylate and a cross-linker EGDMA were copolymerized in the presence of AIBN as an initiator. The refractive index of 1.4348~1.4361, water content of 33.30~34.02%, UV-B transmittance of 4.77~67.50%, UV-A transmittance of 1.45~89.19% and visible transmittance of 32.12~92.21% were obtained. The results of hydrogel lens containing 2,6-difluoropyridine (add 5%) showed antibiosis for staphylococcus aureus. The produced copolymer is suitable for hydrogel soft ophthalmic lenses with antibiotic and anti-UV effect.