• Title, Summary, Keyword: UV (ultraviolet) light

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Introduction of Ultraviolet/Infrared Flame Detector and Method for False Detection Prevention (자외선/적외선 불꽃감지기 소개 및 오동작 방지를 위한 연구)

  • Lim, Byung-Hyun;Ko, Nak-Yong;Hwang, Jong-Sun;Kim, Yeong-Min;Kim, Jong-Man
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • pp.8-11
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    • 2003
  • We propose that when combustible burn with contain carbon, introduce fire detector with sensor of private-use detectable light energy as infrared and ultraviolet in energy of electromagnetic-wave type radiate from flame, method for correct discrimination to resemble fire produce false alarm of detector such as sun light, hot object radiation, are welding. This research using infrared sensor is pyroelectric infrared sensor based black body radiation theory. Ultraviolet sensor is uv Tron using gas multiplication effect to current discharge and photoelectric effect of metal. To have high sensibility and to gain proper output voltage, it has high responsive performance. This research introduced UV/IR compound type flame detector and proposed method of false alarm reduced to resemble fire. The result propres the prevention and extinction of fire technique degree, certificated operation of detector.

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The improvement of characteristics for hydrogenated amorphous silicon thin films by photo-induced CVD (광 CVD에 의한 비정질 실리콘 박막 특성 향상)

  • 김용상;이성규;전명철;박진석;한민구
    • Electrical & Electronic Materials
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    • v.7 no.2
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    • pp.94-99
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    • 1994
  • The purpose of this work is to investigate the interface characteristics of hydrogenated amorphous silicon thin films prepared by PECVD and photo-induced CVD and to examine the annealing effects of ultraviolet irradiation on hydrogenated amorphous silicon thin films which were degraded by visible light illumination. The interface layer thickness of films deposited by photo-induced CVD was about 600-900.angs. while that by PECVD was about 1000-1300.angs.. These results can show that the quality of interface layer in photo induced CVD film is better than that in PECVD sample. The electrical properties are improved by ultraviolet irradiation on visible light soaked a-Si:H films using photo-CVD light sources, probably due to the fact that UV generates phonons in a-Si:H films and anneal the meta stable defects.

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The Effect of Ultraviolet-C Radiation on Disinfection (Ultraviolet-C 조사의 살균 효과)

  • Choi, Houng-Sik;Choi, Kyu-Hwan;Park, So-Yeon
    • Physical Therapy Korea
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    • v.9 no.3
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    • pp.93-99
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    • 2002
  • Traditionally, ultraviolet (UV) has been used for treating the pressure sore and skin wound. The effects of UVA and UVB radiation on disinfection have been reported. The purpose of this study was to examine the effectiveness of UVC radiation on disinfection of Escherichia coli, Staphylococcus aureus, Salmonella typhimurium in vitro. Three bacterium were radiated by UVC (250 nm, 20 seconds) and incubated at $37^{\circ}C$ for 24 hours at the agar culture medium. Kill rates of all three bacterium were 99.9%. UVC radiated on three kinds of bacterium for 30 or 60 seconds. Kill rates were 99.9% both 30 and 60 seconds. This data suggests that UV light at 250 nm could be a useful method to minimize infection and shorten healing time in pressure sore and skin wound condition.

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Development of harmful ultraviolet blocking transparent flexible device using TiO2-x thin film process (TiO2-x 산화물 박막공정을 이용한 유해자외선차단 투명유연소재개발)

  • Kim, Geug Tae
    • Journal of the Korean Crystal Growth and Crystal Technology
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    • v.29 no.3
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    • pp.123-131
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    • 2019
  • In this study, the development of transparent UV blocking material using $TiO_{2-x}$ oxide thin film process was developed. A process technology is related to a process technology for making a sample with ultraviolet-shielding property of visible light transmittance of 78 % or more (total light transmittance at 550 nm) and of a UV cut-off characteristic of more than 95 % at 315 nm in ultraviolet wavelength band. In this study, it is possible to establish a flexible device process condition of high performance ultraviolet (UV) shielding thin film, to design mixed type of transparent flexible device with heterogeneous characteristics and to formulate composite deposition technology, according to various market demands. Establishment of actual roll-to-roll continuous process and equipment and process technology will affect related industries greatly.

Fabrication of ZnO inorganic thin films by using UV-enhanced Atomic Layer Deposition

  • Song, Jong-Su;Yun, Hong-Ro;Seong, Myeong-Mo
    • Proceedings of the Korean Vacuum Society Conference
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    • pp.312.1-312.1
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    • 2016
  • We have deposited ZnO thin films by ultraviolet (UV) enhanced atomic layer deposition using diethylznic (DEZ) and water (H2O) as precursors with UV light. The atomic layer deposition relies on alternating dose of the precursor on the surface and subsequent chemisorption of the precursors with self-limiting growth mechanism. Though ALD is useful to deposition conformal and precise thin film, the surface reactions of the atomic layer deposition are not completed at low temperature in many cases. In this experiment, we focused on the effects of UV radiation during the ALD process on the properties of the inorganic thin films. The surface reactions were found to be complementary enough to yield uniform inorganic thin films and fully react between DEZ and H2O at the low temperature by using UV irradiation. The UV light was effective to obtain conductive ZnO film. And the stability of TFT with UV-enhanced ZnO was improved than ZnO by thermal ALD method. High conductive UV-enhanced ZnO film have the potential to applicability of the transparent electrode.

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The Study of Thermal Effect Suppression and Wavelength Dependence of Azobenzene-coated FBG for UV Sensing Application (UV광 측정용 아조벤젠 코팅된 FBG의 열적 효과 제거 및 파장 의존성에 대한 연구)

  • Choi, Dong-Seok;Kim, Hyun-Kyoung;Ahn, Tae-Jung
    • Korean Journal of Optics and Photonics
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    • v.22 no.2
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    • pp.67-71
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    • 2011
  • In the paper, we have demonstrated an azobenzene-coated fiber Bragg grating (FBG) for monitoring ultraviolet light (UV) intensity in remote measurement. The elasticity of the coated azobenzene polymer is changed by the UV light, which induces a center wavelength change corresponding to the change of the FBG's grating period. The wavelength shift resulting from both UV light and other light with the wavelength out of the UV range was about 0.18 nm. In order to improve the accuracy of the measurement, the center wavelength shift caused by radiant heat of the light source was sufficiently removed by using a thermal filter. The amount of the center wavelength shift was consequently reduced to 0.06 nm, compared to the result without the thermal filter. Also, the FBGs coated by using azobenzene polymer were produced by two different methods; thermal casting and UV curing. Considering temperature dependence, UV curing is more suitable than thermal casting in UV sensor application of the azobenzene-coated FBG. In addition, we have confirmed the wavelength dependence of the optical sensor by means of four different band pass filters. Thus, we found out that the center wavelength shift per unit intensity is 0.029 [arb. unit] as a maximum value at 370 nm wavelength region and that the absorption spectrum of the azobenzene polymer was very consistent with the wavelength dependence of the azobenzene-coated FBG.

Improving the Sensitivity of an Ultraviolet Optical Sensor Based on a Fiber Bragg Grating by Coating With a Photoresponsive Material (광반응 재료가 코팅된 단주기 광섬유격자 기반 자외선센서의 광민감도 향상 연구)

  • Kim, Woo Young;Kim, Chan-Young;Kim, Hyun-Kyoung;Ahn, Tae-Jung
    • Korean Journal of Optics and Photonics
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    • v.26 no.2
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    • pp.83-87
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    • 2015
  • This study was focused on developing an optical sensor that monitors ultraviolet (UV) light. Recently, we proposed and demonstrated a novel, highly sensitive UV sensor based on a fiber Bragg grating (FBG). To ensure that the incident UV light is focused on the FBG surface, the sensor was coated with an azobenzene polymer material that acts as a UV-induced stretchable functional material, in combination with a cylindrical focal lens. In this study we have improved the sensitivity of the sensor by employing a cylindrical focal mirror as a curved reflector, to refocus the UV light passing through the FBG. We considered the performance of several different types of reflectors and chose the optimal radius of curvature for the reflector. Compared to the UV sensor without an auxiliary device, the sensitivity of the FBG sensor with a focal lens and a curved reflector was 15 times as high.

UV Sensitivity of Korean Skin and The Effects of Factors affecting SPF Determination (한국인 피부의 자외선 감수성과 SPF 측정치에 미치는 인자의 영향)

  • 이병곤
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.17 no.1
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    • pp.1-17
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    • 1991
  • Multiport-600 Solar SimulatorR is one of the most recent and convenient in-strument for evaluation of sun protection factor(SPF). In this study, we examined the practicability of the SPF determining system using Multiport -600 and the effects of several factors-light sources, seasons and experimental animals-on the minimal erythema dose(MED) and SPF. We also tested the UV sensitivity according to the sites of Korean people, And the ultraviolet radiation reaching the earth's surface In Seoul have been observed for one year. As a result of this study, the determinig system for SPF using Multiport-600 was proved to be a good system in accuracy and time-saving. The biological activity of fluorescence UV lamp of PUVA-800R was significantly higher than natural light or solar simulator with Xe arc lamp, and the determined MED became lower in inverse proportion to room temperature rise. Skin sensitivity by ultraviolet adiation was hights. in order \circled1 back \circled2 inns, upper arm \circled3 outer upper arm \circled4 foream. We also observed that UV radiation intensity was highest at noon in july and 1 sun burn unit(MED) was 28 minutes at that time.

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Fabrication of Rewritable Pattern Images with Ultraviolet-responsive Polycaprolactone Electrospun Fibers (전기방사에 의한 재기록 가능한 자외선 응답형 폴리카프로락톤 패턴)

  • Ali, Shamshad;Ahmed, Farooq;Khatri, Zeeshan;Kim, Seong Hun
    • Textile Science and Engineering
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    • v.52 no.2
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    • pp.126-131
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    • 2015
  • For the first time, the photochromic spiropyran dye [1'-3'-dihydro-1',3',3'-trimethyl-6-nitrospiro [2H-1-benzopyran-2,2'-(2H)-indole] (indole) was successfully embedded as a guest molecule into the poly(${\varepsilon}$-caprolactone) (PCL) host polymer matrix via the electrospinning technique. The resulting PCL/Indole electrospun fibers exhibit photo-switchable properties without losing depth of color upon alternate irradiation with ultraviolet (UV) and visible light. We found that patterned color images could be recorded on the photochromic PCL/Indole electrospun fiber mats using photo-masked UV irradiation. Subsequent irradiation of the mat with visible light completely erased the recorded patterned color image. The transformation of indole from the colorless form to the colored form upon UV irradiation was confirmed by UV-visible spectrophotometry, fluorescence micrography, and water contact angle measurements. Field emissionscanning electron microscopy images revealed the smooth morphology of the PCL/Indole electrospun fibers. Additionally, the average diameter of the PCL/Indole electrospun fibers was significantly lower than that of the PCL electrospun fibers. Good to excellent ratings were achieved for the washing fastness of the PCL/Indole electrospun fiber mats.

Generation of High Pretilt Angle in a Cell with Oblique non-polarized UV Light Irradiation on Polyimide Surface (폴리이미드막표면위에 경사진 자외선 조사를 이용한 액정셀에서의 고프리틸트각의 발생)

  • 서대식;한정민
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.11 no.6
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    • pp.481-485
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    • 1998
  • We investigated the generation of high pretilt angle for nematic liquid crystal (NLC) in a cell with obilique non-polarized ultraviolet (UV) light irradiation on mixtured polyimide surface. It was found that the monodomain alignment of NLC is obtained with an angle of incidence of 75∼85 degrees on PI surface. We consider that the monodomain alignment of NLC is attributed to anisotropic dispersion force effect to photo-depolymerization of polymer. We successfully observed that the pretilt angle of NLC is generated above 5 degree with an angle of incidence of 75∼85 degrees. It is considered that the pretilt angle generation NLC is attributed to interaction between the LC molecules and the polymer surfaces.

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