• 제목/요약/키워드: UV-A

검색결과 7,059건 처리시간 0.035초

렌즈에서 UV 차단효과의 평가방법 및 적용 (The Estimation Method and Application of UV-cut effect in Lens)

  • 김용근
    • 한국안광학회지
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    • 제6권1호
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    • pp.107-110
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    • 2001
  • 렌즈에서 UV-A선의 차단효율을 평가하기 위해 320~400nm 영역에서 광 투과율을 측정하였다. 기준 CR-39와 sample을 320~400nm 영역에서 광 투과율을 적분하여 면적을 구하였으며, 이들의 면적 대비로 UV-A 차단효율 factor ${\alpha}$, ${\beta}$를 설정하였다. CR-39 렌즈의 질대 차단효율 ${\alpha}$ CR=0.59 값을 얻었다. UV-A 차단효과를 평가할 렌즈의 절대차단효율 ${\alpha}$ 값이면 상대차단효율 ${\beta}$ 값은 $1.69{\alpha}$ 값을 얻었다. 절대적 및 상대적 UV 제거 지수는 각각 $a=(1-{\alpha}){\times}100%$, $b=(1-{\beta}){\times}100%$을 이용하여 얻었다.

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UV, 전기분해 및 UV+전기분해 공정을 이용한 해수 중의 동물성 플랑크톤 제거 (Zooplankton Removal in Seawater using UV, Electrolysis and UV+electrolysis Process)

  • 김동석;박영식
    • 한국환경과학회지
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    • 제30권7호
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    • pp.597-604
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    • 2021
  • The International Maritime Organization (IMO) ballast water management agreement (International Convention for the Control and Management of Ship's Ballast Water and Sediments) came into force on September 8, 2017. This study evaluated the disinfection performance of electrolysis, UV treatment, and electrolysis + UV combined, to improve the treatment of zooplankton (size ≥ 50 ㎛), which is expected to strengthen the standards for biodegradation efficiency. Among the methods used, the disinfection time leading to 100% death was in the order: electrolysis > electrolysis + UV > UV process. For the same level of disinfection performance, the amount of electricity required for the electrolysis, UV, and electrolysis + UV processes were 1,300 W.s, 8,400 W.S, and 4,500 W.s, respectively. The combination of electrolysis + UV process for inactivation of zooplankton in ballast water did not show a synergic effect owing to the slow disinfection time and high power consumption.

EFFECTS OF UV-B RADIATION ON GROWTH AND DEVELOPMENT OF RICE CULTIVARS (ORYZA SATIVA L.).

  • T.Kumagai;Kang, H.S.;J.Hidema;T.Sato
    • 한국식물학회:학술대회논문집
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    • 한국식물학회 1994년도 94 Symposium on Plant science September 10, 1994 Ewha Womans University, Seoul, Korea 94 식물학 심포지움 환경 스트레스와 식물의 반응
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    • pp.29-39
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    • 1994
  • Serious issues about the changes in the environmental conditions on earth associated with human activities have arisen, and the interest in these problems has increased. It is urgent to determine how the expansion of terrestrial UV-B radiation due to the stratospheric ozone depletion influences living matters. In this connection, we have been investigating the effects of UV-B radiation on the growth of rice cultivars (Oryza sativa L.). We report here some physiological and genetic aspects of resistance to inhibitory effects of UV-B radiation on growth of rice cultivars as described below. Elevated UV radiation containing large amount of UV-B and a small amount of UV-C inhibited the development of plant height, the photosynthetic rate and the chlorophyll content in rice plants in a phytotron. Similar results were obtained in experiments, in which elevated UV-V radiation. Similar results were obtained in experiments, in which elevated UV-B radiation (transmission down to 290 nm) was applied instead of UV-B radiation containing a small amount of UV-C. The inhibitory effects of UV radiation was alleviated by the elevated CO2 atmospheric environment or by the exposure to the high irradiance visible radiation. The latter suggested the possibility that the resistance to the effects of UV radiation was either due to a lower sensitivity to UV radiation or to a greater ability to recover from the injury caused by UV radiation through the exposure to visible radiation. The examination of cultivar differences in the resistance to UV radiation-caused injuries among 198 rice cultivars belonging to 5 Asian rice ecotypes (aus, aman, boro, bulu and tjeleh) from the Bengal region and Indonesia and to Japanese lowland and upland rice groups showed the following: Various cultivars having different sensitivities to the effects of UV radiation were involved in the same ecotype and the same group, and that the Japanese lowland rice group and the boro ecotype were more resistant. Among Japanese lowland rice cultivars, Sasanishiki (one of the leading varieties in Japan) exhibited more resistance to UV rakiation, while Norin 1 showed less resistance, although these two cultivars are closely related. It was thus indicated that the resistance to the inhibitory effects of UV radiation of rice cultivars is not simply due to the difference in the geographical situation where rice cultuvars are cultivated. Form the genetic analysis of resistance to the inhibitory effects of UV radiation on growth of rice using F2 plants generated by reciprocally crossing Sasanishiki and Norin 1 and F3 lines generated by self-fertilizing F2 plants, it was evident that the resistance to the inhibitory of elebated UV radiation in these rice plants was controlled by recessive polygenes.

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폴리카보네이트에 사용된 첨가제의 분석 (Analyses of Additives Applied in a Polycarbonate)

  • 김석준
    • 분석과학
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    • 제13권3호
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    • pp.282-290
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    • 2000
  • 본 연구는 390nm 이하에서 자외선 흡수가 완벽한 폴리카보네이트(광학용)에 첨가된 각종 첨가제를 아세톤으로 추출하거나 용해-침전 방식으로 분리하여 분석하는 것이다. 분리된 첨가제를 정성적으로 분석하기 위해 자외선흡광광도계, FT-IR 및 HPLC로 분석하였다. 분리된 물질은 광안정제 및 산화방지제(1차 및 2차)등의 첨가제와 단량체 및 올리고머가 함유된 복잡한 혼합물로 추정할 수 있다. 분리된 첨가물을 Bondapak $C_{18}$ 칼럼, 메탄올 이동상, PDA (Photodiode Array) 검출기를 사용한 역상(reversed phase, RP) HPLC 분석을 통해 비스페놀 A, Irganox 1010, Cyasorb UV-5411 성분들을 확인할 수 있있다. 또한, 자외선 흡광도를 이용한 정량분석을 통해 폴리카보네이트에 광안정제인 Cyasorb UV-5411가 0.12중량% 함유된 것을 알 수 있었다.

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자외선 흡수제 처리 시 은나노/수지 첨가가 면직물의 기능성에 미치는 영향 (Effect on Functional Properties of the Cotton Fabrics Treated by UV-absorbers with Nanosilver/DMDHEU Treatment)

  • 강미정;권영아
    • 한국의류학회지
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    • 제33권9호
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    • pp.1463-1471
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    • 2009
  • Silver ions or silver nanoparticles have multi-functional properties. The cotton fabrics for providing multi-functional properties were treated with a nanosilver powder, UV-absorbers, and dimethyloldi-hydroxyethyleneurea (DMDHEU) alone and mixed solution. The physical properties, UV protection, antibacterial, and deodorizing properties of treated cotton fabrics were evaluated. The results were as a follows. The UV protection of cotton fabrics were increased by the application of a nanosilver and Uv-absorbers mixture. The UV protection of treated fabrics were improved by nanosilver/DMDHEU/UV-absorbers mixed solution. The wrinkle recovery properties of fabrics treated with DMDHEU and nanosilver improved. The stiffness of fabrics are decreased by a nanosilver/DMDHEU/UV-absorbers mixed solution. The antibacterial properties of the fabrics treated with nanosilver/DMDHEU/UV-absorbers mixed solution is 99.99%. The functional properties of cotton fabrics are shown to be better with aanosilver/DMDHEU/UV-absorbers mixed than treated with nanosilver alone.

오존, UV, 오존/UV 혼합 공정을 이용한 Diethyl Phthalate(DEP)의 제거특성 연구 (Characterization of Diethyl Phthalate(DEP) Removal using Ozone, UV, and Ozone/UV Combined Processes)

  • 정연정;오병수;강준원
    • 대한환경공학회지
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    • 제28권2호
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    • pp.137-143
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    • 2006
  • 본 연구는 오존 단독, UV 단독 및 오존/UV 혼합 공정을 이용하여 DEP의 제거 특성을 알아보고자 수행되었다. 실험 결과로서, 오존/UV 공정에서 가장 높은 제거 효율을 나타냈다. 오존 및 오존/UV 공정에서 DEP의 분해 경로를 파악하기 위해서 pH 변화 및 OH 라디칼($OH^{\circ}$) scavenger 첨가 유무에 따른 제거 정도를 비교하였다. 그 결과, DEP 분해 시 $OH^{\circ}$과의 반응이 주된 반응이며, 오존에 의한 직접 산화 반응 및 UV에 의한 광분해 반응은 무시할 정도로 작았다. 오존 및 오존/UV 공정에서 DEP의 의사일차속도상수를 비교하였을 때, 오존/UV 공정은 일차속도에 잘 일치한 반면 오존 단독 공정에서는 일차속도로 제거되는 경향이 초기에 빠르고 일정한 반응시간 이후에 느려지는 두 영역으로 나뉘어 나타났다. 오존 및 오존/UV 긍정에 의해 생성되는 DEP 산화 부산물을 간접적으로 확인하기 위해 HPLC 스펙트럼을 조사한 결과 미지의 물질이 검출되었으며, 반응시간에 따라 이 물질이 생성되다가 감소하는 일정한 경향을 보였다. 또한, 오존/UV 혼합공정에서 높은 TOC 제거율을 나타내 DEP 및 DEP 산화부산물까지 완전 산화됨을 확인하였다.

Characteristics of Environmental Solar Ultraviolet Irradiance

  • Sasaki, Masako;Oyanagi, Takehiko;Takeshita, Shu
    • Journal of Photoscience
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    • 제9권2호
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    • pp.154-157
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    • 2002
  • Direct, continuous, and accurate measurements of solar ultraviolet irradiance (290-400 nm: UVR) have been carried out since 1990, by using both band-spectral ultraviolet-B (290-320 nm: UV-B) and ultraviolet-A (320-400 nm: UV-A) radiometers at Tokai University in Hiratsuka, Japan (35$^{\circ}$N, 139$^{\circ}$E). From our observations, the following findings are provided: 1) an increasing trend in solar UV -B from Oct. 1990 to Sept. 2000; 2) a regional comparison of solar UVR in Japan; 3) the distinct characteristics of UV-B and UV-A irradiance, such as diffuse property, daily and seasonal variation; and 4) human body protection against solar UVR. An increasing 10-year trend in global solar UV - B in Hiratsuka corresponded to a decrease in the total ozone amount measured at Tsukuba (36$^{\circ}$N, 140$^{\circ}$E), giving supportive evidence for a direct link between these two parameters. Furthermore, a strong correlation was found between solar UV-B and total ozone amount from results of UVR measurements at four Tokai University monitoring stations dispersed throughout Japan. Additional results revealed different diffuse properties in global solar UV and in global solar total (300-3000 nm: Total) irradiances. For example, in the global UVR, the diffuse component was dominant: about 80 % independent of weather, with more than 60 % of global UV-B, and more than 50% of global UV-A with even a cloudless clear sky. On the other hand, the portion of the diffuse in the global total irradiance was very low, less than 10 % on a cloudless clear day. Daily and seasonal variations of UV -B and UV -A irradiances were found to be quite different, because of the marked dependence of UV -B irradiance on the atmospheric ozone amount. Moreover, UV -B irradiance showed large daily and seasonal variations: the ratio between maximum and minimum irradiances was more than 5. In contrast, the variation in UV-A was small: the ratio between maximum and minimum was less than 2. Three important facts are proposed concerning solar UVR protection of the human body: 1) the personal minimal erythema dose (MED); 2) gender based difference in MED values; and 3) proper colors for UVR protective clothing.

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Effects of Hexaconazole on Growth and Antioxidant Potential of Cucumber Seedlings under UV-B Radiation

  • Kim, Tae-Yun;Hong, Jung-Hee
    • 한국환경과학회지
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    • 제21권12호
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    • pp.1435-1447
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    • 2012
  • The present study was conducted to determine the effect of hexaconazole (HEX), a triazole fungicide, on the growth, yield, photosynthetic response and antioxidant potential in cucumber (Cucumis sativus L.) plants subjected to UV-B stress. UV-B radiation and HEX were applied separately or in combination to cucumber seedlings. The growth parameters were significantly reduced under UV-B treatment, however, this growth inhibition was less in HEX treated plants. HEX caused noticeable changes in plant morphology such as reduced shoot length and leaf area, and increased leaf thickness. HEX was quite persistent in inhibiting shoot growth by causing a reduction in shoot fresh and dry weight. HEX noticeably recovered the UV-B induced inhibition of biomass production. Significant accumutation in anthocyanin and flavonoid pigments in the leaves occurred as a result of HEX or UV-B treatments. HEX permitted the survival of more green leaf tissue preventing chlorophyll content reduction and higher quantum yield for photosystemII under UV-B exposure. HEX treatment induced a transient rise in ABA levels in the leaves, and combined application of HEX and UV-B showed a significant enhancement of ABA content which activates $H_2O_2$ generation. UV-B exposure induced accumulation of $H_2O_2$ in the leaves, while HEX prevented UV-B induced increase in $H_2O_2$, indicating that HEX serves as an antioxidant agent able to scavenge $H_2O$ to protect cells from oxidative damage. An increase in the ascorbic acid was observed in the HEX treated cucumber leaves affecting many enzyme activities by removing $H_2O_2$ during photosynthetic processes. The activities of antioxidant enzymes including catalase(CAT), ascorbate peroxidase(APX), superoxide dismutase(SOD) and peroxidase(POD) in the leaves in the presence of HEX under UV-B stress were higher than those under UV-B stress alone. These findings suggest that HEX may participate in the enhanced tolerance to oxidative stress. From these results it can be concluded that HEX moderately ameliolate the effect of UV-B stress in cucumber by improving the components of antioxidant defense system.

$UV/O_3$ 표면처리에 따른 OLEDs 효율 향상에 관한 연구 (Study on Efficiency improvement of OLEDs by surface treatment of $UV/O_3$)

  • 장윤기;김병상;권오관;권영수
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2005년도 추계학술대회 논문집 전기물성,응용부문
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    • pp.142-144
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    • 2005
  • Main purpose of this study is a improved efficiency of Organic light emitting diodes(OLEDs) concerning $UV/O_3$ treatment. We investigated the efficiency of OLEDs by $UV/O_3$ treatment of ITO surface. We measured current density-voltage, luminance-voltage characteristics in different $UV/O_3$ treatment time and observed ITO surface roughness by using AFM(Atomic Force Microscope). The fundamental structure of the OLEDs was $ITO/NPB/Alq_3/LiF/Al$. We performed $UV/O_3$ treatment and found that $UV/O_3$ treatment enhanced the performance of OLEDs. We also found that change of surface roughness according to difference time a $UV/O_3$ treatment

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UV/Ozone 조사에 의한 PET 직물의 편면 발수가공 (One-side Water-repellent Finish of PET Fabrics using UV/Ozone)

  • 김수진;장진호
    • 한국염색가공학회지
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    • 제23권2호
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    • pp.100-106
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    • 2011
  • UV-curable water-repellent finish was carried out to impart one-side repellency to the PET fabrics using a formulation of a UV-active fluorocarbon agent and a water soluble photoinitiator. The aqueous formulation was padded on the PET fabrics and it was subsequently UV-cured. The unirradiated side of the cured fabrics was made to wetteable to water by the prolonged UV/ozone irradiation. The influence of photoinitiator concentration, agent concentration and UV energy for photodegradation on the performance of the finished fabrics were investigated. The difference in the functional property of front and back sides was examined by measuring water repellency at each side of the treated fabrics, which resulted in four rating difference between two-side. The UV-cured and photodegraded PET surfaces were characterized by ATR, ESCA and FE-SEM.