• 조명전기설비학회논문지
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• 제25권3호
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• pp.7-14
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• 2011

Many countries and researchers in the lighting field have focused on the LED light source as a solution to energy savings and environmental pollution. The LED light source consumes less power, has a long life and is highly economical. It is vibration and shock-resistant, and environment friendly as well. But LED lighting has some problems. In particular, the photobiological safety of LED light sources is emerging as an issue. Ultraviolet radiation from the LED light source emitted directly to the human body over a long period of time is harmful. In this paper, UV radiation from white LED was measured. Finally, the LED light source emits UV radiation, but it is relatively small when compared to others.

• Journal of Microbiology and Biotechnology
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• 제30권12호
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• pp.1937-1943
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• 2020

Although classical metabolic engineering strategies have succeeded in developing microbial strains capable of producing desired bioproducts, metabolic imbalance resulting from extensive genetic manipulation often leads to decreased productivity. Thus, abiotic strategies for improving microbial production performance can be an alternative to overcome drawbacks arising from intensive metabolic engineering. Herein, we report a promising abiotic method for enhancing lycopene production by UV-C irradiation using a radiation-resistant ΔcrtLm/crtB+dxs+ Deinococcus radiodurans R1 strain. First, the onset of UV irradiation was determined through analysis of the expression of 11 genes mainly involved in the carotenoid biosynthetic pathway in the ΔcrtLm/crtB+dxs+ D. radiodurans R1 strain. Second, the effects of different UV wavelengths (UV-A, UV-B, and UV-C) on lycopene production were investigated. UV-C irradiation induced the highest production, resulting in a 69.9% increase in lycopene content [64.2 ± 3.2 mg/g dry cell weight (DCW)]. Extended UV-C irradiation further enhanced lycopene content up to 73.9 ± 2.3 mg/g DCW, a 95.5% increase compared to production without UV-C irradiation (37.8 ± 0.7 mg/g DCW).

• 한국안전학회지
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• 제16권1호
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• pp.1-8
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• 2001

All objects emit thermal radiation and this radiation is the basis of the techniques used to detect flames. The usual phenomena occurring in the initial stage of the fire are generally invisible products of a combustion and visible smoke. Liquid or gaseous materials do not undergo a smoldering stage so that fires develop very rapidly. Also, the heat generated by the initial flames is usually not sufficient to activate a heat detector. In this case the most effective criterion for automatic fire detection is the flame. According to the fire regulation of korea, the compulsory standard provided that a flame detector shall be installed in a place that the attachment height of detector is higher than 20 m, chemical plants, hangar, refinery, etc.. The results of the research and development are discriminated between a flame and other radiant emitters, developed a UV detector tube contains an inert gas which absorbs UV radiation, developed PZT pyroelectric element is based on the use of photovoltanic cell, developed IR band-pass filter that only allow a 4.3 $\mu\textrm{m}$ radiation wavelength to reach the sensors and developed UV-IR combination flame detector combined into a single detection device.

• 한국작물학회지
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• 제50권1호
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• pp.39-44
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• 2005

This study was conducted to examine the physiological and biochemical responses against UV-B radiation in the seedling of 15 different rice cultivars, having the different physiological sensitivities. Out of 15 rice cultivars tested, moderate and susceptible groups showed significant decreases in biomass and RGR (relative growth rate). Contents of total chlorophyll were reduced remarkedly by irradiation of UV-B. In all rice cultivars tested, the content of chlorophyll a was strongly decreased, while the contents of chlorophyll b were slightly reduced without showing clear different among three groups and 15 cultivars. Carotenoid content was largely reduced by UV-B radiation, whereas polyamine content was moderately increased. The contents of MDA (malondialdehyde) that reflect the level of lipid peroxidation of cell membranes were clearly increased by UV-B stress, showing higher content in susceptible cultivars than moderate and torelant cultivars. The physiological important parameters highly related to visible injury were leaf color, chlorophyll, carotenoid, and lipid peroxidation, whereas biomass and polyamines were not closely correlated. Based on this results, it was concluded that changes of visible injury and the contents of chlorophyll and MDA could be adequately applied and utilized as physiological indicators to UV-B radiation.

• 한국산림과학회지
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• 제88권4호
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• pp.469-476
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• 1999

본 연구는 증가되는 UV-B 환경에 대한 양수(陽樹)와 중성수(中性樹)의 생장 및 생리적 반응을 탐구하고자 자작나무(Betula platyphylla var. japonica Hara)와 물푸레나무(Fraxinus rhynchophylla Hance)의 유묘(幼苗)를 대상으로 14주 동안 3 수준의 UV-B(ambient UV-$B_{BE}$, ambient+3.2, +$5.2\;KJ\;m^{-2}s^{-1}$) lamp가 설치된 야외포장에서 실시되었다. 자작나무와 물푸레나무 유묘의 수고생장(樹高生長), 근원경생장(根元徑生長), 엽면적(葉面積) 및 건물생산(乾物生産)은 UV-B 증가에 의하여 감소되었다. UV-B 증가에 의해 물푸레나무 유묘 잎의 기공저항(氣孔低抗)은 커졌으며, 엽록소(葉綠素), carotenoid 함량의 감소는 자작나무에서 보다 물푸레나무에서 더 뚜렷하였다. UV-B 흡수물질(吸收物質)의 현저한 증가는 나타나지 않았지만 자작나무에 비해 물푸레나무의 경우 다소 증가하는 경향이었다. 이러한 결과들은 UV-B 증가 환경에 대한 공시 두 수종의 생리적(生理的), 생화학적(生化學的) 반응이 다르다는 것을 의미한다.

• International Union of Geodesy and Geophysics Korean Journal of Geophysical Research
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• 제21권1호
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• pp.31-46
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• 1993

대기 가열율과 복사속의 연직 분포를 계산하기 위하여 two-stream/delta-Eddington 근사법을 이용한 복사전달모형이 개발되었다. 이 모형의 결과를 ICRCCM의 결과와 비교하므로써 모형의 완성도를 평가하였다. 이 모형은 정확성 뿐 아니라 경제적인 면에서도 태양복사를 계산하는데 적합한 것으로 증명되었다. 대기 꼭대기에서의 복사속과 지표에서의 복사속 간의 관계를 비교하므로써 자외선 B 영역(UV-B; 280-320nm)의 특징들이 검토되었다. 이 영역에서는 강한 오존 흡수가 있어 UV-B의 관계가 2차 함수로 나타난다. 또한, 성층권 오존 감소와 화산 폭발로 기인한 성층권 에어로졸 안개가 UV-B 복사에 미치는 영향을 다양한 태양의 천정각에서 조사했다. 태양의 천정각이 증가함에 따라 지표 UV-B도 증가하였다. 성층권 에어로졸은 후방 산란을 통해 행성 반사도를 증가시켰다. 행성 반사도는 에어로졸 효과로 인해 태양의 천정각이 증가함에 따라 증가한다. 그러나, 행성 반사도의 변화가 태양의 천정각 변화에 따라 민감하게 나타나지는 않는다. 이것은 태양의 천정각이 클 때 에어로졸의 산란 효과가 상대적으로 긴 복사 경로에서 포화되었기 때문일 것이다. 끝으로, 화산 폭발에서 비롯된 성층권 에어로졸이 지표 UV-B 복사 강도에 미치는 지역적 영향이 추정되었다. 고위도에서는 에어로졸의 광자 포획(photon trap)이나 일몰 효과로 복사 강도가 증가하는 반면 저위도에서는 감소한다. 고위도에서 에어로졸의 산란과 오존 흡수는 지표 UV-B 복사의 최대 증가는 봄 기간 중에 양 반구 모두 중위도에서 나타난다.

• Journal of Photoscience
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• 제9권2호
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• pp.445-447
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• 2002

The compositional changes in mycosporine-like amino acids (MAAs) were investigated in the marine dinoflagellate Scrippsiella sweeneyae exposed to four different spectral compositions and five relative intensities of UV-B (280-320 nm) to UV-A (320-400 nm) + photosynthetically available radiation (PAR: 400-700 nm). Neither dose nor wavelengths of UVR significantly affected the growth rates. UVR caused a significantly increase in cell volume. Cell volume in the >280nm treatment was more than two times greater at 6.8 % of UVR intensity. Production of UVR induced MAAs was dependent on the dose of UVR. However. the induction of MAAs was related to the cell growth. Greater induction of MAAs was observed at shorter wavelengths. The composition of MAAs varied with increasing light intensity of UVR.

• Journal of Radiation Protection and Research
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• 제30권1호
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• pp.27-30
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• 2005

New possibilities are discussed for cholesteric liquid crystals (CLC) as sensor materials for detection of ionizing radiation, biologically active UV radiation, and the presence of hazardous vapors in atmosphere. A distinguishing property of CLC-based detectors is their 'bioequivalence', i.e., mechanisms of their response to external factors essentially imitate the corresponding mechanisms of biological tissues. Such detectors can ensure sufficiently high sensitivity to make feasible their use as alarm indicators or in biophysical studies. Specific examples ate given of sensor compositions and their response characteristics.

• 한국가스학회지
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• 제1권1호
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• pp.113-119
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• 1997

UV 화염감기의 분진분위기에서의 성능저하를 고찰하기 위하여 세제분말, 탄진 및 분말 소화약제의 분진운을 형성하였고 LPG 및 가솔린 화염을 사용하여 UV 화염감지기의 감지성능을 고찰하였다. 분진 분위기 하에서의 UV 화염감지기의 성능을 분진의 농도와 분진층의 거리가 증가함에 따라 뚜렷한 증가를 보였으며, 분진의 화학적, 물리적 특성에 커다란 영향을 받았다. 따라서 UV 화염감지기를 분진 분위기에서 사용한 경우 특별한 주의를 기울일 필요가 있는 것으로 사려된다.

• 한국물환경학회지
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• 제25권4호
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• pp.547-552
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• 2009

Because of refractory property of light, the travel path of UV light becomes longer than the straight line and shorter solely in water as UV light passes sequentially through air, quartz and water. Note that water significantly absorbs UV light. Hence, UV intensity shall be estimated to be lower when refraction is neglected than it is considered. Reflection is also critical for the design of UV radiation system. While the reflection at the interface of air and quartz is low enough to ignore, it is too high to be ignored at the interface of quartz and water. Assuming constant power, smaller length to width ratio of UV reactor is beneficial and single-lamp system is preferred to multi-lamps. Under the given cross section, optimal lamp positions could be decided. For example of an elliptical reactor with dual lamps, the optimal lamp locations shall be the 1/3 and 2/3 position of the longer axis.