• 제목/요약/키워드: UV light

검색결과 1,840건 처리시간 0.033초

통발용 형광 미끼통의 유인 효과 개선을 위한 자외선 조도에 관한 연구 (Study on the UV illuminance to improve on attraction effect of fluorescent bait cage for pots)

  • 장호영
    • 수산해양기술연구
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    • 제47권4호
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    • pp.316-326
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    • 2011
  • In this study, the entrapped number is investigated on the UV light with different illuminance to fluorescent bait cage for swimming crab in order to find the appropriate illuminance which has the best attraction effect of fluorescent bait cage for pots. In addition, preference to the light, arrival time and residence time at light area are compared and analyzed to fluorescent bait cage and non-fluorescent bait cage for American lobster at the UV light and ordinary light according to the illuminance condition. Pot with red non-fluorescent bait cage at the no lighting (<0.01lux), pot with blue fluorescent bait cage at the 20W UV lighting (0.16lux) and pot with blue fluorescent bait cage at the 30W UV lighting (0.22lux) were soaked for 6 hours and the entrapped number of swimming crab was examined. The mean entrapped number of swimming crab in pot with red non-fluorescent bait cage at the no lighting (<0.01lux) was 1.0, but the mean entrapped number of swimming crab in pot with blue fluorescent bait cages at the 20W UV lighting (0.16lux) and 30W UV lighting (0.22lux) were 1.4 and 0.4, respectively (P<0.05). The rate of preference to the blue fluorescent bait cage at the UV lighting shows 1.6-4.8 times higher than that of preference to the red non-fluorescent bait cage at the ordinary lighting. In addition, The rate of preference to the blue fluorescent bait cage at the UV lighting is higher when the illuminance of ordinary light is same as or is lower than that of UV light (P<0.05). However, the preference to the light depending on gender shows no significant difference (P>0.05). The arrival time to UV light area of lobster is shown as 1.2-2.4 times faster than that to ordinary light area. Generally, it is shown that arrival time to UV light area is faster than the arrival time to ordinary light area when the illuminance of ordinary light is the same as or lower than that of UV light (P<0.05). However, arrival time to the light area depending on gender shows no significant difference (P>0.05). The residence time at UV light area of lobster is 1.2-1.7 times longer than that at ordinary light area. The residence time depending on different illuminance of ordinary light and genders showed no significant difference (P>0.05).

폴링미드표면에 편광된 UV광을 경사조사시의 프리틸트각의 발생과 편광성분의 상호관계 (Relationship between the pretilt angle generation and the polarization component with oblique polarized UV light irradiation on polyimide surface.)

  • 서대식;박두석
    • 한국전기전자재료학회논문지
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    • 제12권1호
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    • pp.75-80
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    • 1999
  • In this study, we have investigated the relationship between the generation of pretilt angle and the polarization component in cells with UV light irradiation on polyimide (PI) surface. It was found that the generated pretilt angle is about $1.4^{\circ}$ with S-polarized UV light irradiation of $75^{\circ}$ on PI surface; it may be attributed to the asymmetry triangular of polymer surface with oblique S-polarized UV light irradiation on PI surface. Also, we measured that the generated pretilt angle is about $2.0^{\circ}$ with oblique P polarized UV light irradiation of $75^{\circ}$ on PI surface. Consequently, we suggest that the generated pretilt angle of the NLC is attributed to the interaction between the LC molecules and the polymer surface with oblique polarized UV light irradiation on PI surface.

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Changes in Bioactive Compounds Contents of 'Maehyang' and 'Seolhyang' Strawberry Fruits by UV Light Illumination

  • Kim, Sung-Kyeom;Bae, Ro-Na;Chun, Chang-Hoo
    • 원예과학기술지
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    • 제29권3호
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    • pp.172-180
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    • 2011
  • The net photosynthetic rate of 'Seolhyang' strawberry plants was measured daily for 7 days after treatment at three UV illumination dosages (0, 9.8, and 29.5 $kJ{\cdot}m^{-2}$). The net photosynthetic rates of the strawberry plants with 9.8 and 29.5 $kJ{\cdot}m^{-2}$ UV light illumination decreased by 20.2 and 61.4%, respectively, at 7 days after UV light treatments. UV treatments with two illumination dosages (7.9 and 15.7 $kJ{\cdot}m^{-2}$) altered the phenolic compounds contents during the cultivation period when compared to those in the control fruits. The anthocyanin content with 7.9 $kJ{\cdot}m^{-2}$ UV light illumination of 'Seolhyang' increased by 18.7% compared with those in control fruits at the 11 DAT. However, the anthocyanin content of 'Maehyang' was not significantly different among treatments during experiment period. The highest level of ellagic acid was found with 7.9 $kJ{\cdot}m^{-2}$ UV light illumination in both cultivars at the 11 DAT. Our results showed that strawberries illuminated with UV light during cultivation period had higher bioactive compounds contents than control fruits. These results suggest that UV light treatments may be a useful non-chemical way of promoting strawberry fruits quality.

쥐의 적출 대동맥에 자외선 조사로 유발된 photorelaxation 기작의 생리학적 특성 (Physiological characterization of mechanism on UV light-induced photorelaxation in isolated rat aorta)

  • 이한기;홍용근;김경
    • The Journal of Korean Physical Therapy
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    • 제15권2호
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    • pp.146-156
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    • 2003
  • Isolated rat thoracic aorta which is pharmacologically precontracted by phenylephrine induces photorelaxation when exposed to long wave length UV-light. The aim of the present study was to characterize the mechanism of UV-light induced by photorelaxation in the rat aorta. 1. UV light relaxed both endothelium-intact and -denuded rat aortic rings contracted by phenylephrine. The magnitude of relaxation on UV light was dependent on the exposure time and slightly greatly in endothelium-denuded rings than in endothelium-intact preparations. 2. L-NAME (10 nM - 100 $\mu$M) but not D-NAME completely inhibited the photorelaxation in a concentration dependent manner. 3. The UV-induced relaxation was inhibited by methylene blue (1 - 100 uM), and verapamil (100 nM), and removal of extracellular $Ca^{2+}$. In contrast, UV-light induced photorelaxation was potentiated by $N^{w}$-nitro-L-arginine (L-NNA) treatment. These results suggest that UV light-induced photorelaxation may be due to nitric oxide from exogenously administered L-arginine as well as endogenous nitric oxide donors such as amino acid and arginine derivatives

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직선편광된 UV광을 폴리이미드막에 조사한 경우의 프리틸트각의 발생과 편광성분의 상호관계 (Relationship between the pretilt angle generation and the polarization component with linearily polarized UV light irradiation on polymer surface.)

  • 서대식;박두석;한정민
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 1998년도 하계학술대회 논문집 D
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    • pp.1391-1394
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    • 1998
  • In this paper, we investigated the generation of pretilt for nematic liquid crystal (NLC) in a cell with linearly polarized ultraviolet (UV) light irradiation on polyimide (PI) surface. The pretilt angle of the NLC increases with increasing the incident angle in the cells with S-wave polarized UV light irradiation on PI surface. It is considered that the pretilt angle of the NLC increased due to decreasing the UV light intencity. We suggest that the pretilt angle of the NLC is attributed to asymmetry triangular of the polymer surface with S-wave polarized UV light irradiation on PI surface. Also, we consider that the asymmetry triangular of the Polymer not formed with P-wave polarized UV light irradiation on PI surface. Therefore, the pretilt angle of the NLC is attributed to asymmetry triangular of the polymer surface with UV light irradiation on PI surface.

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태양광과 UV-A 빛 하에서 ZnO 을 이용한 Reactive Black 5의 광분해작용 (Photomineralisation of Reactive Black 5 with ZnO using Solar and UV-A Light)

  • Amisha, S.;Selvam, K.;Sobana, N.;Swaminathan, M.
    • 대한화학회지
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    • 제52권1호
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    • pp.66-72
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    • 2008
  • 태양광과 UV-A빛 조건하에 수용액 속에서 디아조염료의 광 촉매분해반응에 대해 조사를 해보았다. 염료의 광 촉매 분해반응에는 염료의 농도, 촉매 량, 그리고 pH와 같은 여러 가지 영향 요소들이 존재한다. 과산화수소, ammonium persulphate와 isopropanol 등의 첨가는 분해비율에 대해 큰 영향을 미친다. Langmuir-Hinshelwood model에 근거한 광 분해반응의 동역학적분석은 광분해반응은 대략적으로 pseudo first order kinetics을 따름을 알 수 있다. 광분해산물로 이산화탄소, 질산염, sulphate 이온 등이 증명되었다. 광 촉매, ZnO는 태양광 하에서보다 UV-A빛 하에서 더욱 효율적임을 발견하였다.

Action Spectra of Apoptosis Induction and Reproductive Cell Death in L5178Y cells in UV-B Region

  • Mizuho Aoki;Yoshiya Furusawa;Higashi, Sho-ichi;Masakatsu Watanabe
    • Journal of Photoscience
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    • 제9권2호
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    • pp.454-456
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    • 2002
  • It is important to determine the action spectrum of UV-B radiation contained in the sunlight to estimate the risk of skin cancer. We have investigated action spectra for induction of apoptosis and reproductive cell death in L5178Y cells using the Okazaki Large Spectrograph at NIBB. L5178Y cells were exposed to light at different wavelengths in UV-B or UV-A region. Frequencies of apoptosis induction and reproductive cell death were determined by counting cells with chromatin condensation, and by the colony formation assay, respectively. The measured sensitivity spectra for the two end-points were in very good agreement. Sensitivity decreased steeply with increase of wavelength in UV-B region and remains nearly constant in UV-A region. The action spectra were also slightly steeper than that for the minimum erythematic dose (MED), but very similar to the light absorption spectrum of DNA in UV-B region. On the other hand, the spectra for both endpoints were similar to MED spectrum but not DNA spectrum in the UV-A region. Also different time-course and morphological difference of apoptosis were found between UV-B (long time, fragmentation) and UV-A (short time, shrinkage) region. These results suggest that DNA damage induced by UV-B light triggers apoptosis and reproductive cell death, but other damaged targets (membrane, protein and so on) trigger these effects in UV-A region.

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비접촉식 자외선 반응조에서 자외선 강도 분포의 광학적 특성 (Optical characteristics of the UV intensity distribution in a non-contact type UV photoreactor)

  • 전화봉;윤정원;김성홍
    • 상하수도학회지
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    • 제26권2호
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    • pp.257-264
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    • 2012
  • The concept of a non-contact type of UV disinfection system was introduced in this study. UV lamps and their quartz sleeves hang over the water surface and there is no interface between the sleeve and water. Obviously, there is no fouling. Based on optical laws and other UV distribution models, a detail mathematical model for a non-contact type UV disinfection system was developed in this study. Pathway length of UV light in a non-contact type photoreactor is longer than that in a submerged type photoreactor because the light is more refractive while passing through 3 interfaces of medium. But the pathway length passing through the water media is not significantly longer than that in a submerged type photoreactor so, the absorption of UV light by water is not significantly different from the other system. Due to the reflection effect, UV intensity is rapidly decreased as the horizontal distance from the light source is increased. The reflective attenuation in a non-contact type photoreactor is higher than that in a submerged type photoreactor. These mean that the short photoreactor is advantageous than the narrow-long photoreactor for the non-contact type photoreactor in an optical point of view.

Color Change and Tensile Properties of Wood Flour Reinforced Polypropylene Composites; Influence of Photostabilizers

  • Lee, Sun-Young
    • 한국응용과학기술학회지
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    • 제26권2호
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    • pp.171-178
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    • 2009
  • A comparative analysis of the hindered amine light stabilizers (HALS) and UV abosrber (UVA) and their respective photostabilizing effect on wood plastic composites (WPCs) are reported in this study. The influence of accelerated weathering on the mechanical properties of the composites and the microscopic morphology of a degraded layer on the cross section and the surface were studied. UV absorbers were more efficient at preventing composite lightening than was UV stabilizer. The amount of whitening decreased with the increase of photostabilizers. With the addition of a UV absorber (Tinuvin360), the tensile modulus and strength of the composites increased slightly. However, the addition of a light stabilizer (Tinuvin770) and a UV absorber decreased the tensile modulus and strength of the composites. After 250 and 500 hr exposure, tensile modulus and strength of the un stabilized and stabilized composites decreased. The tensile strength of UV absorber (Chimassorb81)-stabilized composites was significantly greater than that of control and light stabilizer (Tinuvin770)- and UV absorber (Tinuvin360)-stabilized composites. UV absorber-stabilized samples showed less whitening and photodegradation than control and light stabilizer-stabilized samples.

Synthesis of CdSe-TiO2 Photocatalyst and Their Enhanced Photocatalytic Activities under UV and Visible Light

  • Lim, Chang-Sung;Chen, Ming-Liang;Oh, Won-Chun
    • Bulletin of the Korean Chemical Society
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    • 제32권5호
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    • pp.1657-1661
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    • 2011
  • In this study, CdSe-$TiO_2$ photocatalyst were synthesized by a facile solvothermal method and characterized by X-ray diffraction (XRD), Scanning electron microscopy (SEM) with energy dispersive X-ray (EDX) analysis and UV-vis diffuse reflectance spectrophotometer. The photocatalytic activity was investigated by degrading methylene blue (MB) in aqueous solution under irradiation of UV light as well as visible light. The absorbance of degraded MB solution was determined by UV-vis spectrophotometer. The results revealed that the CdSe-$TiO_2$ photocatalyst exhibited much higher photocatalytic activity than $TiO_2$ both under irradiation of UV light as well as visible light.