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Author Bará, S.
Title (up) Black-body luminance and magnitudes per square arcsecond in the Johnson-Cousins BVR photometric bands Type Journal Article
Year 2019 Publication Photonics Letters of Poland Abbreviated Journal Photon. Lett. Pl.
Volume 11 Issue 3 Pages 63
Keywords Skyglow; night sky brightness; luminance; photometric
Abstract A relevant amount of light pollution studies deal with the unwanted visual effects of artificial light at night, including the anthropogenic luminance of the sky that hinders the observation of the celestial bodies which are a main target of ground-based astrophysical research, and a key asset of the intangible heritage of humankind. Most quantitative measurements and numerical models, however, evaluate the anthropogenic sky radiance in any of the standard Johnson-Cousins UBVRI photometric bands, generally in the V one. Since the Johnson-Cousins V band is not identical with the visual CIE V-lambda used to assess luminance, the conversion between these two photometric systems turns out to be spectrum-dependent. Given its interest for practical applications, in this Letter we provide the framework to perform this conversion and the transformation constants for black-body spectra of different absolute temperatures.
Address Dept. Física Aplicada, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Galicia
Corporate Author Thesis
Publisher Photonics Society of Poland Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2080-2242 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 2685
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Author Gallaway, T.; Olsen, R.N.; Mitchell, D.M.
Title (up) Blinded by the Light: Economic Analysis of Severe Light Pollution Type Journal Article
Year 2013 Publication Journal of Economic Insight Abbreviated Journal J Econ Insight
Volume 39 Issue 1 Pages 45-63
Keywords Economics; light pollution
Abstract This paper examines severe light pollution such as commonly found in large urban areas. Light pollution is the unintended negative consequences of poorly designed and injudiciously used artificial lighting. Light pollution generates significant costs including wasted energy and damage to human health, wildlife, recreation, and the beauty of the night sky. Typically, light-pollution models emphasize population density and ignore economic factors. Economic analysis of the issue has been singularly limited. Previous economic research has focused on widespread, but very low levels of light pollution. This paper makes a unique contribution by analyzing economic factors of severe light pollution. The paper utilizes economic data from the World Bank and unique remote sensing data for 184 countries to quantify the economic causes of severe light pollution. Fractional logit models confirm the importance of population and economic factors alike.
Address Department of Economics, Missouri State University; TerrelGallaway(at)missouristate.edu
Corporate Author Thesis
Publisher Missouri Valley Economic Association Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0361-6576 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 2338
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Author Mortazavi, S.A.R., Parhoodeh, S., Hosseini, M.A., Arabi, H., Malakooti, H., Nematollahi, S., Mortazavi, G., Darvish, L., Mortazavi, S.M.J.
Title (up) Blocking Short-Wavelength Component of the Visible Light Emitted by Smartphones’ Screens Improves Human Sleep Quality Type Journal Article
Year 2018 Publication Journal of Biomedical Physics and Engineering Abbreviated Journal
Volume 8 Issue 4 Pages 375-380
Keywords Human Health
Abstract Background: It has been shown that short-wavelength blue component of the visible light spectrum can alter the circadian rhythm and suppress the level of melatonin hormone. The short-wavelength light emitted by smartphones’ screens can affect the sleep quality of the people who use these devices at night through suppression of melatonin.

Objectives: In this study, we examined the effects of covering the screens of smartphones with different filters (changing the effective wavelength of the light) on sleep delay time in 43 healthy students.

Materials and Methods: Volunteer students were asked to go to bed at 23:00 and to use their mobile phones in bed for watching a natural life documentary movie for 60 minutes. No filter was used for one night while amber and blue filters were used for other 2 nights. Photospectrometry method was used to determine the output spectrum of the light passing through the filters used for covering the screens of the mobile phones. The order for utilizing amber or blue filters or using no filter was selected randomly. After 1 hour, the participants were asked to record their sleep delay time measured by a modified form of sleep time record sheet.

Results: The mean sleep delay time for the “no-filter” night was 20.84±9.15 minutes, while the sleep delay times for the nights with amber and blue filters were 15.26±1.04 and 26.33±1.59 minutes, respectively.

Conclusion: The findings obtained in this study support this hypothesis that blue light possibly suppresses the secretion of melatonin more than the longer wavelengths of the visible light spectrum. Using amber filter in this study significantly improved the sleep quality. Altogether, these findings lead us to this conclusion that blocking the short-wavelength component of the light emitted by smartphones’ screens improves human sleep.
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
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ISSN ISBN Medium
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Notes Approved no
Call Number NC @ ehyde3 @ Serial 2077
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Author Brelsford, CC; Robson, TM
Title (up) Blue light advances bud burst in branches of three deciduous tree species under short-day conditions Type Journal Article
Year 2018 Publication Trees Abbreviated Journal
Volume 32 Issue 4 Pages 1157-1164
Keywords Plants
Abstract During spring, utilising multiple cues allow tree species from temperate and boreal regions to coordinate their bud burst and leaf out, at the right moment to capitalise on favourable conditions for photosynthesis. Whilst the effect of blue light (400–500 nm) has been shown to increase percentage bud burst of axillary shoots of Rosa sp., the effects of blue light on spring-time bud burst of deciduous tree species have not previously been reported. We tested the hypotheses that blue light would advance spring bud burst in tree species, and that late-successional species would respond more than early-successional species, whose bud burst is primarily determined by temperature. The bud development of Alnus glutinosa, Betula pendula, and Quercus robur branches, cut from dormant trees, was monitored under two light treatments of equal photosynthetically active radiation (PAR, 400–700 nm) and temperature, either with or without blue light, under controlled environmental conditions. In the presence of blue light, the mean time required to reach 50% bud burst was reduced by 3.3 days in Betula pendula, 6 days in Alnus glutinosa, and 6.3 days in Quercus robur. This result highlights the potential of the blue region of the solar spectrum to be used as an extra cue that could help plants to regulate their spring phenology, alongside photoperiod and temperature. Understanding how plants combine photoreceptor-mediated cues with other environmental cues such as temperature to control phenology is essential if we are to accurately predict how tree species might respond to climate change.
Address
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Publisher Place of Publication Editor
Language Summary Language Original Title
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ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 1847
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Author Zhao, X.; Zhang M.; Che, X.; Zou, F.
Title (up) Blue light attracts nocturnally migrating birds Type Journal Article
Year 2020 Publication The Condor Abbreviated Journal
Volume in press Issue Pages in press
Keywords Animals
Abstract Light pollution is increasing and artificial light sources have great impacts on animals. For migrating birds, collisions caused by artificial light pollution are a significant source of mortality. Laboratory studies have demonstrated that birds have different visual sensitivities to different colors of light, but few field experiments have compared birds’ responses to light of different wavelengths. We used 3 monochromatic lights (red, green, and blue) and polychromatic yellow light to study the impact of wavelength on phototaxis at 2 gathering sites of nocturnally migrating birds in Southwest China. For both sites, short-wavelength blue light caused the strongest phototactic response. In contrast, birds were rarely attracted to long-wavelength red light. The attractive effect of blue light was greatest during nights with fog and headwinds. As rapid urbanization and industrialization cause an increase in artificial light, we suggest that switching to longer wavelength lights is a convenient and economically effective way to reduce bird collisions.

摘要

目前地球上光污染日益严重,五颜六色的人工光源对生态系统造成了很大影响。就鸟类而言,在世界各地已发生了很多鸟类撞击人工光源的事件。实验室研究表明,鸟类对不同颜色的光有不同的视觉敏感度,但很少有野外实验比较鸟类对不同波长光的反应。我们在中国西南地区的两个夜间候鸟迁徙聚集点使用三种单色光(红、绿、蓝)和一种复合光(黄),研究了光波长对的候鸟趋光性的影响。研究表明,短波长的蓝光引起了候鸟最强烈的趋光性反应。相反,鸟类很少被长波长的红光所吸引。特别是在有雾和逆风的夜晚,蓝光的吸引力最大。由于快速的城市化和工业化导致人造光的增加,我们认为使用长波光是一个减少鸟类碰撞光源的方便和经济有效的方式。
Address
Corporate Author Thesis
Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2896
Permanent link to this record