• 제목/요약/키워드: ultraviolet-A

검색결과 2,125건 처리시간 0.033초

초기형 별 방향 성간운의 CO 와 H2 비율 계산 (CO TO H2 RATIO OF INTERSTELLAR MOLECULAR CLOUDS IN THE DIRECTIONS OF EARLY TYPE STARS)

  • 박재우;이대희;민경욱
    • Journal of Astronomy and Space Sciences
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    • 제21권4호
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    • pp.243-248
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    • 2004
  • FUSE(Far Ultraviolet Spectroscopic Explorer)를 이용해 7개의 초기형 별 방향에 존재하는 CO 흡수선을 관측했다. BEFS(Berkeley Extreme and Far-ultraviolet Spectrometer)로 관측한 54개의 초기형 별들 중에서 이번 논문에서는 시선방향으로 1개의 성간운만 존재하는 7개의 별(HD 37903, HD 97991, HD 149881, HD 156110, HD 164794, HD 214080, HD 219188)들을 선택해서 분석했다. CO 분자의 분석을 위해 자외선 영역에서 수소분자의 흡수선에 의해 가려지지 않는 E-X(0-0)($1076{\AA}$) 흡수선이 있는지 확인했으며 그 결과 3개의 별 방향에 존재하는 성간운에 대해서 CO 흡수선이 있는 것을 발견했다. 그 흡수선의 분석을 통해 성간운에 존재하는 CO의 기둥밀도를 구했고, 이번 논문에서의 결과와 이전에 구했던 수소분자의 기둥밀도로부터 CO분자와 수소분자 사이의 비율(CO to $H_2$ ratio)을 계산할 수 있었다.

자외선 스펙트럼을 이용한 별의 표면온도 결정 (DETERMINATION OF STELLAR SURFACE TEMPERAURE USING ULTRAVIOLET SPECTRA)

  • 강영운;지나현;한미려;최영준;한원용;이우백
    • Journal of Astronomy and Space Sciences
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    • 제15권1호
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    • pp.91-100
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    • 1998
  • 자외선 영역에서 색지수와 유효온도의 상관관계를 구하기 위한 pilot project 로 25개의 표준상태에 대하여 유효온도와 색지수를 산출하였다. 유효온도는 자외선 영역의 IUE 저분산 스펙트럼의 에너지 분포 곡선을 Kurucx 모델과 비교하여 산출하였고, 자외선 색지수는 IUE 저분산 스펙트럼의 플럭스를 $300{\AA}$ 단위로 적분하여 등급으로 환산하여 산출하였다. 자외선 영역으 상관관계는 가시관선 영역의 상관관계와 유사한 형태로 나타났다.

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자외선 처리된 Epoxy/Glass Fiber의 표면 열화 특성에 관한 연구 (A Study on the Surface Degradation Properties of Epoxy / Glass fiber Treated with Ultraviolet Rays)

  • 이백수;이덕출
    • 대한전기학회논문지:전기물성ㆍ응용부문C
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    • 제48권2호
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    • pp.86-91
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    • 1999
  • In order to analyse the degradation process of epoxy/glass fiber for outdoor condition, FRP laminate was exposed to the wavelength of ultraviolet rays and evaluated by comparing contact angle, surface resistivity, surface potential decay, and ESCA spectrum respectively. As irradiation energy are increased, the surface properties were steeply decreased in the range of 300[nm]. But the measured values within the scope of400[nm]∼440[nm] showed a increase as compared with the untreated ones. Also, fromthe result of ESCA spectrum, it was confirmed plenty of oxygen groups on the spot showing the maximum decrease of surface properties and the existence of ether groups on the surface of coloring phase. We can conclude that the degradation phenomena on the surface of epoxy composites are dominated by the induction of ester and carboxyl groups.

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

  • 김용상;이성규;전명철;박진석;한민구
    • E2M - 전기 전자와 첨단 소재
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    • 제7권2호
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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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Relationship between Stratospheric Ozone and Solar Ultraviolet B Irradiance in Taegu, Korea

  • Suh, Kye-Hong;Cho, Young-Joon
    • The Korean Journal of Ecology
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    • 제24권2호
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    • pp.117-119
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    • 2001
  • Solar ultraviolet-B (UV-B) irradiances incident on a horizontal surface at Taegu, Korea during 1996-1998 were calculated with 5 minute averages of measurements taken every 30 seconds by a broadband UV-B sensor. The average, maximum and minimum of daily UV-B dose were 11.31, 22.04 and 3.20kJ m$^{-2}$ day$^{-1}$ , respectively, for the measuring period. Variations in stratospheric ozone concentration measured from space explain 85% of changes in the daily UV-B dose. It was expected that decrease of 50 Du in stratospheric ozone cause increase of 24.1% in daily UV-B dose in this study.

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FUE 공정에 의한 Ballast Water처리 (Treatment of Ballast Water By Filtration -Ultraviolet radiation-Electrolytic Process)

  • 박상호;김억조;박성진;김인수
    • 해양환경안전학회지
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    • 제8권2호
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    • pp.23-27
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    • 2002
  • Reballasting at sea, as recommended by the IMO guidelines, currently provides the best-available measure to reduce the risk of transfer of harmful aquatic organisms, but is subject to serious ship-safety limits. It is therefore extremely important that alternative, effective ballast water management and treatment methods are developed as soon as possible, to replace reballasting at sea. Filtration-Ultraviolet radiation-Electrolytic process (FUE) was evaluated for disinfection of seawater used In ballast water Optimal current density and UV light intensity were 2.0A/dm$^2$ and, 220㎼/$\textrm{cm}^2$/m with which 100% reduction time was 2sec in a Ultraviolet radiation-Electrolytic process. This study showed that FUE process was effective for the disinfection of commonly isolated bacteria and bacillus from ballast water.

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피부 미용에 있어서 자외선 차단제의 개발 및 유효 안전성 (Development and Efficiency-Stabilization of UV Blocking Agents Used to Skincare)

  • 김상춘;남기대;이향우
    • 한국응용과학기술학회지
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    • 제12권2호
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    • pp.157-163
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    • 1995
  • The ultraviolet blocking agents used to skincare are largely classified ultraviolet scattering agent and ultraviolet absorbent agents. There are UVC, UVB, and UBA in ultraviolet ray(UV) showing shorter wavelength than visible light. Both visible light and UVA give rise to 1st dark-skinned phenomena. On exposure of the skin to UV, phenomena of skin variation are termed sunburn or suntan. There are chronic and acute adverse reactions in skin response to UV. The latter is caused by UVB, which has mainly effects on the skin. But lately due to destruction of ozone layer, UVA has more serious irritation on the skin than UVB. In this paper spectrometric properties of UV absorbent agents such as PABA, octyl-PABA, Urocanic acid, and 2-hydroxy-4-methoxy benzophenone in vitro have been investigate. As results, it was found that the three fomer were more suitable than the last. UV scattering measurements on the sample used inorganic pigments showed that pigments containing titanium dioxide had a better scattering effects than the inorganic pigments such as $Fe_2O_3$, $Al_2O_3$, etc.

줄풀염색에 의한 모직물의 염색성과 기능성 (Dyeability and Functionality of Wool Fabrics Dyed with Zizania latifolia Turcz. extract)

  • 고은숙;이혜선
    • 한국의류산업학회지
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    • 제21권2호
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    • pp.231-236
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    • 2019
  • This study investigated the proper dyeing conditions, color fastness and functionality of wool fabrics dyed with Zizania latifolia Turcz. We also tried to improve light fastness through treatment with benzophenone ultraviolet absorber. The dyeing of wool fabrics using Zizania latifolia Turcz was good even without pretreatment or mordanting treatment. Optimal wool fabric dyeing conditions were colorant concentration of 200% (o.w.f.), dyeing temperature of $100^{\circ}C$, dyeing time of 80 minutes and a dye bath pH of 3. Color fastness of dyed wool fabrics to washing, rubbing, perspiration and light was 4-5, 5, 4-4-5 (acidic), 4-5 (alkaline) and 2 respectively. The results after treatment with ultraviolet absorber for improving the fastness of daylight were improved to 3-4 grade. The UV protection rate were increased after dyeing and the deodorization of ammonia gas improved to 98%. Bacterial reduction rate (Staphylococcus aureus) of wool fabrics was excellent at 99.9%. All dye fastness (except for light fastness) was excellent; in addition, the functionality of wool fabrics dyed with Zizania latifolia Turcz also improved. The results are expected to be applied to various fields because they indicate excellent results after treatment with ultraviolet absorber for improving the fastness of daylight.

자외선 및 초음파 공정에 의한 수용액 상의 PCBs 분해 (Removal of PCBs in Aqueous Phase in Ultraviolet (UV), Ultrasonic (US), and UV/US Processes)

  • 이덕영;손영규
    • 한국지하수토양환경학회지:지하수토양환경
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    • 제26권4호
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    • pp.1-7
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    • 2021
  • The removal of PCBs (Polychlorinated biphenyls) in aqueous phase was investigated in the ultraviolet (UV) process, ultrasonics (US) process and ultraviolet/ultrasonic (UV/US) process using PCB No.7 and Aroclor 1260. For PCB No.7 relatively high removal efficiency over 90% was obtained during 20 min in the UV process and UV/US process. On the other hand, lower removal efficiency of 50 - 70% was achieved for it consisted of individual congeners of PCBs containing 3~8 of chlorine atom. It was found that the dechlorination reaction (the photolytic cleavage of C-Cl bond) was considered as a main removal mechanism in the UV process while PCBs were removed by cavitation-induced radical reaction in the US process. No significant dechlorination occurred in the US process. Consequently, it was suggested that the UV process or UV/US process was applicable for the removal of PCBs in aqueous phase in terms of the removal efficiency and operation time. In addition, the application of saturating gas such as Ar and Air could be considered to control redox condition and enhance the severity of acoustic cavitation for the removal of PCBs.

비무장지대 평화생명벨트 인접해안에서의 레저관광활동 가이드라인을 위한 자외선 반사량 원격측정 (Remote Measurement of Ultraviolet Reflections for the Guidelines for Leisure Tourism Activities on the Adjacent Coast of the Demilitarized Zone Peace Life Belt)

  • 어재선;최철재
    • 한국전자통신학회논문지
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    • 제17권3호
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    • pp.499-506
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    • 2022
  • 2021년 동해북부선 착공으로 비무장지대(Demilitarized Zone:DMZ)의 평화적 활용의 기대치가 높아지고있다. 이에 따라 비무장지대를 안보생태관광으로 활용한 인근 해변에서의 레저관광 활동에 대비해야 한다. 그러나 오존층의 파괴로 인한 지표면 자외선(Ultravilolet:UV) 양의 증가에도 불구하고 아직까지 자외선 노출 위험가이드라인이 없다. 본 논문에서는 원격탐사를 이용한 비무장지대 인접 해안에서의 자외선 반사량 측정하고 분석하였다. 제시된 결과가 인근지역 레저관광 활동에서의 자외선 가이드라인 마련에 기초자료로 활용되기를 기대한다.