• 제목/요약/키워드: ultraviolet spectrum

검색결과 158건 처리시간 0.028초

원거리의 물과 오일을 구별할 수 있는 UV형광측정시스템 개발과 분석에 대한 연구 (Long Distance Identification of Water and Oil using an Ultraviolet Fluorescence Measurement System)

  • 백경훈;이준석;전수정;박보람;박성욱
    • 센서학회지
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    • 제31권4호
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    • pp.266-270
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    • 2022
  • Owing to the rising volume of seaborne trade, oil spills damage the marine environment for over 250 yearly. Thus, various analysis methods such as the Fourier-transform infrared (FTIR), Raman spectroscope, and gas chromatography are used to monitor oil spills at sea, but these methods are expensive. Recently, to reduce operational costs, an underwater fluorometer was adopted. However, this approach is not ideal for the remote sensing of oil spills because the device gets submerged in the sea. In this study, we have designed and developed a monitoring system that uses ultraviolet fluorescence to detect spilled oil or water from a distance, as well as proposed an analyzing method defining based on water Raman signal and QF535. Each fluorescence spectrum of water, oil (crude oil), and Bunker A was obtained using the system, and was calculated and analyzed from the spectrum individually. Based on the results of the analysis, we could successfully identity water and oil at a long distance.

느타리버섯 생장에 미치는 광 감응성 작용 스펙트럼 (An Action Spectrum for Light-induced Growth rate in Pleurotus ostreatus)

  • 이갑득
    • 생명과학회지
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    • 제10권5호
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    • pp.519-523
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    • 2000
  • The action spectrum for light-induced growth of fruit body in Pleurotus ostreatus has been studied by irradiation at various wavelengths. Effective wavelengths were distributed from near ultraviolet to blue region of spectrum. The most effect of light was observed in the region between 340 to 520 nanometers. The growth weigth obtained from which has been irradiated 144 hours in the region of 340-520 nm increases 74%, on the contrary the observed growth weight has been observed in the longer wavelengths than 620 nm. The pileus size was promoted 30$\times$32% in the region of 340-500 nm, and retarded 22$\times$19% in the dark. the strip length was rearded 12% in the region of 340-500 nm, and promoted 38% in the dark. The color thickness for pileus is getting light in longer wavelengths.

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느타리버섯의 균사체 및 원기 형성에 미치는 광 감응성 작용 스펙트럼 (An Action Spectrum for Light-induced Mycelial Growth and Primordium Formation in Pleurotus ostreatus)

  • 이갑득;강병수;박용기
    • 생명과학회지
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    • 제6권3호
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    • pp.193-197
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    • 1996
  • The action spectrum for mycelial growth and fruitbody primordium formation in Pleurotus ostreatus has been studied by irradiation at various wavelengths. Effective wavelengths. Effective wavelengths were distributed from near ultraviolet to blue region of spectrum. The most effect of light was observed in the region between 340 to 500 nanometers. The light intensity required to obtain of the maximum effect at the most effective wavelengths(430-500nm), was over 6.8 mW/Cm$^{2}$. Up to 6.8 mW/Cm$^{2}$, the primordium formed about 25 hr after the start of illumination. The higher the light intensity, the earlier the formation of the primordium formation : Up to about 6.8 mW/Cm$^{2}$.

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우로칸 알킬에스테르의 합노(合盧) 및 광학효과(光學效果) (The Synthesis of Urocanic Alkyl Ester and Photolysis)

  • 노승호;이향우;남기대
    • 한국응용과학기술학회지
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    • 제8권1호
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    • pp.45-49
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    • 1991
  • The synthesis of urocanic acid which was started D-fructose, and its alkyl esters, urocanic ethyl ester and urocanic isobutyl ester, were prepared by esterificated. Urocanic ethyl ester and urocanic isobutyl ester were insoluble in water and soluble most organic solvents (ethanol, benzene, toluene, pyridine, THF, DMF) which adds to their practical applicability, and absorb ultraviolet light of greater wavelength than the free acid and there by are more effective for shielding sensitive materials, including the humanbody, from the chemically most effective portion of the solar ultraviolet spectrum.

호주산 갈탄의 미생물에 의한 가용화 연구: 전처리 방법이 가용화에 미치는 영향 (Biosolubilization of Australian lignite: effect of pretreatment method on biosolubilization)

  • 신현재;양지원
    • KSBB Journal
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    • 제7권1호
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    • pp.73-78
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    • 1992
  • 곰팡이의 일종인Poria cocos, Trichodermareesei, Candide tropicalis, Aspergillus niger를 이용하여 호주산 갈탄의 액화를 연구하였다. 갈탄을 전처리하는 방법을 달리하여 전처리가 갈탄의 액화에 미치는 영향에 관하여 알아보았으며, 질산과 과산화수소가 호주산 갈탄을 액화하는데 우수한 전처리제라는 사실을 확인하였다. 사용한 여러 균주 가운데 Poria cocos가 가장 뛰어난 액화능을 나타내었으며, 석탄 액화 물질의 구조를 Infrared, Nuclear magnetic resonance, Ultraviolet 분광법을 사용하여 예측하였다.

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피부암의 병인과 예방 (Pathogenesis and prevention of skin cancer)

  • 오병호
    • 대한의사협회지
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    • 제61권11호
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    • pp.644-648
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    • 2018
  • The incidence of skin cancer has continuously increased in Korea, probably due to sun exposure and increases in the aging population. Ultraviolet light, a well-known risk factor for skin cancer, can cause DNA damage, mutation, and immune suppression, followed by abnormal proliferation. To prevent photocarcinogenesis, the appropriate use of sunscreen should be emphasized. Using broad-spectrum sunscreens with sun protection factor values of 15 or higher and frequent reapplication are recommended. Controversy exists about whether vitamin D synthesis is inhibited by the use of sunscreen. However, considering that skin cancer most commonly develops on the head and neck area, applying it to the face and neck is reasonable in terms of balancing the risk-benefit ratio.

부유대역법을 이용한 단결정Ga2O3의 광학적 특성 (Optical Properties of Ga2O3 Single Crystal by Floating Zone Method)

  • 김진기;김종수;김광철
    • 반도체디스플레이기술학회지
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    • 제20권4호
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    • pp.78-82
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    • 2021
  • The Ga2O3 single crystal was grown through a floating zone method, and its structural and optical properties were instigated. It has a monoclinic crystal structure with a (100) crystal orientation and an optical band gap energy of 4.6 eV. It showed an average transmittance of 70% in the visible region. At room temperature, its photoluminescent spectrum showed three different peaks: the ultraviolet at 360 nm, the blue-green at 500 nm, and the red peaks at 700 nm. Especially, at liquid nitrogen temperature, the ultraviolet peak was optically active while the others were quenched.

죽재(竹材) Dioxane Lignin의 UV, IR Spectrum에 대하여 (On the UV and IR Spectra of Dioxane Lignin from Bamboo Culm)

  • 문창국;조종수
    • Journal of the Korean Wood Science and Technology
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    • 제15권4호
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    • pp.26-31
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    • 1987
  • 맹종죽, 왕대, 솜대 Dioxane Lignin의 UV, IR spectrum의 특징(特徵)을 조사(調査)하여 본 바, 그 결과(給果)를 요약하면 다음과 같다. 1. UV spectrum에 있어서는 일반적(一般的)인 Lignin spectrum과 같이 Maximum peak, Shallow minium peak, Minimum peak의 3개소(個所)를 보였는데 Max. peak는 210nm 부근(附近), Shallow peak는 260-270nm에, Minimum peak는 280nm부근(附近)에 있었다. 2. 280nm부근(附近)의 Minimum peak는 Lignin이 갖는 특징적(特徵的)인 peak로서 일반(一般) 침엽수재(針棄樹材) Lignin이나 활엽수(闊葉樹) Lignin과는 달리 282-285nm에서 흡광도(吸光度)가 꼭 같아 아주 완만한 peak 를 보여 주었다. 3. IR spectrum에 있어서는 방향핵(芳香核) 흡수대(吸收帶)는 $1550cm^{-1}$ 부근(附近)에 있고 1040-$1130cm^{-1}$부근(附近)과 1230-$1275cm^{-1}$에서의 Spectrum 형태(形態)는 활엽수(闊葉樹)에 가깝고 침엽수재(針葉樹材) Lignin의 spectrum과는 상반되는 모습을 보여 주었다.

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STANDARIZING THE EXTRATERRESTRIAL SOLAR IRRADIANCE SPECTRUM FOR CAL/VAL OF GEOSTATIONARY OCEAN COLOR IMAGER (GOCI)

  • Shanmugam, Palanisamy;Ahn, Yu-Hwan
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume I
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    • pp.86-89
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    • 2006
  • Ocean color remote sensing community currently uses the different solar irradiance spectra covering the visible and near-infrared in the calibration/validation and deriving products of ocean color instruments. These spectra derived from single and / or multiple measurements sets or models have significant discrepancies, primarily due to variation of the solar activity and uncertainties in the measurements from various instruments and their different calibration standards. Thus, it is prudent to examine model-to-model differences and select a standard reference spectrum that can be adopted in the future calibration and validation processes, particularly of the first Geostationary Ocean Color Imager (GOCI) onboard its Communication Ocean and Meterological Satellite (COMS) planned to be launched in 2008. From an exhaustive survey that reveals a variety of solar spectra in the literature, only eight spectra are considered here seeing as reference in many remote sensing applications. Several criteria are designed to define the reference spectrum: i.e., minimum spectral range of 350-1200nm, based completely or mostly on direct measurements, possible update of data and less errors. A careful analysis of these spectra reveals that the Thuillier 2004 spectrum seems to be very identical compared to other spectra, primarily because it represents very high spectral resolution and the current state of the art in solar irradiance spectra of exceptionally low uncertainty ${\sim}0.1%.$ This study also suggests use of the Gueymard 2004 spectrum as an alternative for applications of multispectral/multipurpose satellite sensors covering the terrestrial regions of interest, where it provides spectral converge beyond 2400nm of the Thuillier 2004 spectrum. Since the solar-activity induced spectral variation is about less than 0.1% and a large portion of this variability occurs particularly in the ultraviolet portion of the electromagnetic spectrum that is the region of less interest for the ocean color community, we disregard considering this variability in the analysis of solar irradiance spectra, although determine the solar constant 1366.1 $Wm^{-2}$ to be proposed for an improved approximation of the extraterrestrial solar spectrum in the visible and NIR region.

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Ultraviolet A Induces Immunosuppression, Protection or Memory Enhancement Depending on Dose, while Ultraviolet B is Immunosuppressive and Tolerogenic over a Large Dose Range

  • Halliday, Gary M.;Byrne, Scott N.
    • Journal of Photoscience
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    • 제9권2호
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    • pp.197-200
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    • 2002
  • UVR-induced immunosuppression contributes to skin cancer. The aim was to construct accurate dose response curves for primary and secondary contact sensitivity for solar-simulated UVR (ssUVR; 290-400nm), UVA and UVB as the role of UVA in immunosuppression is controversial. We used a xenon arc source. The mice were immobilised, enabling accurate dosing. C57BL/6 mice were immunosuppressed at half the dose of ssUVR required to cause sunburn but not by higher doses (up to the sunburn dose). Thus, ssUVR causes systemic immunosuppression only over a narrow, low dose range. UVA caused suppression at low but not high doses whereas UVB induced immunosuppression at all doses tested. 8 weeks later the mice were resensitised to assess tolerance. Mice exposed to the minimum immunosuppressive dose of ssUVR prior to primary sensitisation were tolerant to re-sensitisation. However, at higher doses of ssUVR, these mice were protected from tolerance. Interestingly, while low doses of UV A caused immunosuppression, even lower doses enhanced the response to the second sensitisation. Higher doses of UVA had no affect. UVB induced tolerance in a dose related manner. Thus, ssUVR only induces immunosuppression and tolerance over a narrow dose range. Both UVA and UVB are immunosuppressive at this dose, while higher doses of UVA protect from the suppressive effects of UVB. Surprisingly very low doses of UVA enhanced memory development. Thus UVR has complex effects on the immune system depending on dose and spectrum.

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