• Title/Summary/Keyword: UV-A

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Analysis of Properties of UV Corona on Insulator in Salt Water Environments (염수 환경 열화 상태를 모의한 절연애자의 자외선 코로나 특성 분석)

  • Kim, Young-Seok;Choi, Myeong-Il;Kim, Chong-Min;Bang, Sun-Bae;Shong, Kil-Mok;Lee, Myeong-Jun;Lee, Woo-Chang
    • Proceedings of the KIEE Conference
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    • 2011.07a
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    • pp.1590-1591
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    • 2011
  • In this paper, the UV corona camera was developed using the solar blind and Multi Channel Plate(MCP) technology for the target localization of UV camera. UV camera developed a $6.4^{\circ}{\times}4.8^{\circ}$ of the field of view as a conventional camera to diagnose a wide range of slightly enlarged, and power equipment to measure the distance between the camera and the distance meter has been attached. The UV camera was developed and measured using a UV image, as applied voltage increased ultraviolet images of the phenomenon could be obtained. And we investigated properties of UV corona image on insulator in salt water environments. From the results, the breakdown voltage was decreased and UV images were taken at low voltages and the UV image is rapidly increased with increasing High voltage.

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The internal UV-line-strength relations of early-type galaxies

  • Jeong, Hyun-Jin;Yi, Suk-Young K.;Bureau, Martin;Davies, Roger L.
    • The Bulletin of The Korean Astronomical Society
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    • v.36 no.2
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    • pp.66.2-66.2
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    • 2011
  • The unexpected rising flux of early-type galaxies at decreasing ultraviolet (UV) wavelengths is a long-standing mystery. One important observational constraint is the correlation between UV-optical colours and Mg2 line strengths found by Burstein et al. (1988). The simplest interpretation of this phenomenon is that the UV strength is related to the Mg line-strength. Under this assumption, we expect galaxies with larger Mg gradients to have larger UV colour gradients. By combining UV imaging from GALEX, optical imaging from MDM and SAURON integral-field spectroscopy, we investigate the spatially-resolved relationships between UV colours and stellar population properties of 34 early-type galaxies from the SAURON survey sample. We find that galaxies with old stellar populations show tight correlations between the FUV colours (FUV-V and FUV-NUV) and the Mg b index, $H{\beta}$ index and metallicity [Z/H]. We have also derived logarithmic internal radial colour, measured line strength and derived stellar population gradients for each galaxy and again found a strong dependence of the FUV-V and FUV-NUV colour gradients on both the Mg b line-strength and the metallicity gradients. In particular, global gradients of Mg b and [Z/H] with respect to the UV colour across galaxies are consistent with their local gradients within galaxies, suggesting that the global correlations also hold locally. From a simple model based on multi-band colour fits of UV upturn and UV-weak galaxies, we have identified a plausible range of parameters that reproduces the observed radial colour profiles. In these models, the centers of elliptical galaxies, where the UV flux is strong, are enhanced in metals by roughly 60% compared to UV-weak regions.

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A Study on On-line ARC Welding Monitoring using IR and UV sensor (IR 및 UV센서를 이용한 아크 용접 품질 모니터링에 관한 연구)

  • Yun, Chung-Seop
    • Proceedings of the KWS Conference
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    • 2005.06a
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    • pp.314-316
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    • 2005
  • 이 논문에서는 아크 용접시 발생하는 IR신호와 UV호의 상호 관계를 알아보려고 레이저 용접진단에 사용되는 IR-UV 센서 모니터링 시스템을 적용하였다. 그 결과 IR신호 크기는 용접폭에 관련이 있고, 펄스 형태의 UV신호는 IR신호 증가율이 임계값을 넘으면 나타나는 것을 알 수 있다.

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Applicability Investigation of E.coli, RNA and DNA Bacteriophages for Possible Indicator Microorganisms Based on the Inactivation Effectiveness by UV (UV 불활성화 효과에 의거한 E.coli, RNA 및 DNA 박테리오파지의 대체 지표 미생물로서의 적용성 검토)

  • Kim, Il-Ho;Wahid, Marfiah AB;Tanaka, Hiroaki
    • Journal of Korean Society of Environmental Engineers
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    • v.32 no.11
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    • pp.1063-1068
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    • 2010
  • This study compared UV and UV/$H_2O_2$ inactivation of E.coli, a possible indicator microorganism for fecal contamination of water, and $Q{\ss}$ phage, an indicator for pathogenic viruses. UV inactivation of $Q{\ss}$, T4 and lambda phages in actual secondary effluent was investigated, too. As a result, similar inactivation efficiency between $Q{\ss}$ phage and E.coli was observed during UV treatment, while $Q{\ss}$ phage showed higher resistance to UV/$H_2O_2$ than E.coli. $Q{\ss}$ phage resistance to UV or UV/$H_2O_2$ does not reflect those of all pathogenic viruses. However, the result tells that the use of E.coli inactivation efficiency in evaluating microbiological safety of water could not always ensure the sufficient safety from pathogenic viruses. Meanwhile, $Q{\ss}$ phage showed less resistance to UV than T4 and lambda phages, indicating that the use of $Q{\ss}$ phage as an indicator virus may bring insufficient disinfection effectiveness by causing the introduction of lower UV dose than required. Consequently, it can be thought that T4 or lambda phages would be more desirable indicators in ensuring the sufficient disinfection effectiveness for various pathogenic viruses.

Analysis of Image and Development of UV Corona Camera for High-Voltage Discharge Detection (고전압 방전 검출용 자외선 코로나 카메라 개발 및 방전 이미지 분석)

  • Kim, Young-Seok;Shong, Kil-Mok;Bang, Sun-Bae;Kim, Chong-Min;Choi, Myeong-Il
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.25 no.9
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    • pp.69-74
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    • 2011
  • In this paper, the UV corona camera was developed using the solar blind and Multi Channel Plate(MCP) technology for the target localization of UV image. UV camera developed a $6.4[^{\circ}]{\times}4.8[^{\circ}]$ of the field of view as a conventional camera to diagnose a wide range of slightly enlarged, and power equipment to measure the distance between the camera and the distance meter has been attached. UV camera to measure the discharge count and the UV image was developed, compared with a commercial camera, there was no significant difference. In salt spray environments breakdown voltage was lower than the normal state, thereby discharging the image was rapidly growing phenomenon.

A Study on the removal of B.T.X by UV Photooxidation-Activated Carbon (광산화-활성탄 복합공정에 의한 B.T.X. 분해에 관한 연구)

  • Jeong, Chang Hun;Bae, Hae Ryong
    • Journal of Environmental Science International
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    • v.13 no.1
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    • pp.41-45
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    • 2004
  • In this study, The decomposition of gas-phase Benzene and Toluene, Xylene in air streams by direct UV Photolysis, UV/TiO$_2$ and UV/TiO$_2$/A.C process was studied. The experiments were carried out under various UV light intensities and initial concentrations of B.T.X to investigate and compare the removal efficiency of the pollutant. B.T.X was determined by GC-FID of gas samples taken from the a glass sampling bulb which was located at reactor inlet and outlet by gas-tight syringe. From this study, the results indicate that UV/TiO$_2$/A.C system (photooxidation-photocatalytic oxidation-adsorption process) is ideal for treatment of B.T.X from the small workplace. Although the results needs more verifications, the methodology seems to be reasonable and can be applied for various workplace (laundry, gas station et al.).

A Study on the UV Intensity Models and their Affecting Factors (자외선 강도 산정 모델과 영향 인자에 관한 연구)

  • Kim, Dooil;Choi, Younggyun;Kim, Sunghong
    • Journal of Korean Society of Water and Wastewater
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    • v.22 no.4
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    • pp.421-427
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    • 2008
  • UV disinfection is widely used in water treatment facilities and wastewater treatment plant because of its effectiveness to removal of pathogen and Giardia which is resistant to traditional chemical disinfection. As a design and performance tool of UV disinfection system, 3 dimensional UV intensity models were composed and simulated to compare each other and to find affecting factors in this study. Reflection, refraction and absorption are important parameters in UV intensity model and MPSS and MSSS model can reflect these parameters while LSI model can not. Absorption is the most important parameters among the reflection, refraction, absorption and shadowing so, this should not be neglect. Based on this simulation, shadowing effect is negligible when the number of installed lamp is a few but, this effect can not be neglectable when the number of installed lamp is quite a few. The errors according to shadowing effect is increased as the number of lamp installed increased.

The effect of micro/nano-scale wafer deformation on UV-nanoimprint lithography using an elementwise patterned stamp (다중양각스탬프를 사용하는 UV 나노임프린트 리소그래피공정에서 웨이퍼 미소변형의 영향)

  • 정준호;심영석;최대근;김기돈;신영재;이응숙;손현기;방영매;이상찬
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2004.10a
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    • pp.1119-1122
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    • 2004
  • In the UV-NIL process using an elementwise patterned stamp (EPS), which includes channels formed to separate each element with patterns, low-viscosity resin droplets with a nano-liter volume are dispensed on all elements of the EPS. Following pressing of the EPS, the EPS is illuminated with UV light to cure the resin; and then the EPS is separated from several thin patterned elements on a wafer. Experiments on UV-NIL were performed on an EVG620-NIL. 50 - 70 nm features of the EPS were successfully transferred to 4 in. wafers. Especially, the wafer deformation during imprint was analyzed using the finite element method (FEM) in order to study the effect of the wafer deformation on the UV-NIL using EPS.

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Design of UV-Molding Process to Maximize the Replication Properties in Microstructures (미세구조체의 전사 특성을 향상시키기 위한 UV 성형 공정의 설계)

  • Kim, Dong-Mook;Kim, Seok-Min;Sohn, So-Young;Kang, Shin-Ill
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.3
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    • pp.450-454
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    • 2003
  • It is important to control the processing conditions to maximize the replication quality of UV-molded microstructure. In the present study, the tip radius anil surface roughness of V-groove structure were measured to quantify the replication quality. UV-curing dose and the applied pressure were experimentally selected as the governing Processing conditions that affect the replication quality of the UV-molded part. Finally. an experimental optimization technique combining central composite design and desirability function approach was used to maximize the replication quality of UV-molded structure.

A Study on the Degradability of Pharmaceuticals during UV Treatment (자외선 처리시의 의약품류의 분해도에 관한 연구)

  • Kim, Ilho
    • Journal of Korean Society on Water Environment
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    • v.28 no.6
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    • pp.902-910
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    • 2012
  • The photodegradation characteristics of 30 pharmaceuticals were investigated by batch experiments using Ultraviolet (UV) reactor. The investigated pharmaceuticals include antibiotics, analgesics and antiarrhythmic agents etc. Tested water was prepared by simultaneously spiking 30 pharmaceuticals into pure water, and each experiment was conducted using 3 types of UV lamps. As a result, batch experiments showed that reactions of all the investigated pharmaceuticals followed pseudo-first order reaction regardless of the applied UV lamps. Among the pharmaceuticals, Cyclophosphamide, 2-Quinoxaline carboxylic acid and Clarithromycin proved to be the most UV-resistant compounds. Contrarily, Ceftiofur, Diclofenac and Ketoprofen were easily degraded by all the UV lamps. Dissolved organic carbon (DOC) concentration hardly changed although the concentration of the pharmaceuticals concentration gradually decreased with time, indicating that the degradation of parent pharmaceuticals may produce their intermediates during UV treatment.