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Author Skeldon, A.C.; Phillips, A.J.K.; Dijk, D.-J.
Title The effects of self-selected light-dark cycles and social constraints on human sleep and circadian timing: a modeling approach Type Journal Article
Year 2017 Publication Scientific Reports Abbreviated Journal Sci Rep
Volume 7 Issue Pages (down) 45158
Keywords human health, lighting
Abstract Why do we go to sleep late and struggle to wake up on time? Historically, light-dark cycles were dictated by the solar day, but now humans can extend light exposure by switching on artificial lights. We use a mathematical model incorporating effects of light, circadian rhythmicity and sleep homeostasis to provide a quantitative theoretical framework to understand effects of modern patterns of light consumption on the human circadian system. The model shows that without artificial light humans wakeup at dawn. Artificial light delays circadian rhythmicity and preferred sleep timing and compromises synchronisation to the solar day when wake-times are not enforced. When wake-times are enforced by social constraints, such as work or school, artificial light induces a mismatch between sleep timing and circadian rhythmicity ('social jet-lag'). The model implies that developmental changes in sleep homeostasis and circadian amplitude make adolescents particularly sensitive to effects of light consumption. The model predicts that ameliorating social jet-lag is more effectively achieved by reducing evening light consumption than by delaying social constraints, particularly in individuals with slow circadian clocks or when imposed wake-times occur after sunrise. These theory-informed predictions may aid design of interventions to prevent and treat circadian rhythm-sleep disorders and social jet-lag.
Address University of Surrey, Surrey Sleep Research Centre, Guildford, GU2 7XP, UK
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 2045-2322 ISBN Medium
Area Expedition Conference
Notes PMID:28345624 Approved no
Call Number SU @ spitschan @ Serial 1638
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Author Lin, Y.; Liu, Y.; Sun, Y.; Zhu, X.; Lai, J.; Heynderickx, I.
Title Model predicting discomfort glare caused by LED road lights Type Journal Article
Year 2014 Publication Optics Express Abbreviated Journal Opt. Express
Volume 22 Issue 15 Pages (down) 18056
Keywords LED; LED lighting; glare; road safety; traffic
Abstract To model discomfort glare from LED road lighting, the effect of four key variables on perceived glare was explored. These variables were: the average glare source luminance (Lg), the background luminance (Lb), the solid angle of the glare source from the perspective of the viewer; and the angle between the glare source and the line of sight. Based on these four variables 72 different light conditions were simulated in a scaled experimental set-up. Participants were requested to judge the perceived discomfort glare of these light conditions using the deBoer rating scale. All four variables and some of their interactions had indeed a significant effect on the deBoer rating. Based on these findings, we developed a model, and tested its general applicability in various verification experiments, including laboratory conditions as well as real road conditions. This verification proved the validity of the model with a correlation between measured and predicted values as high as 0.87 and a residual deviation of about 1 unit on the deBoer rating scale. These results filled the gap in estimating discomfort glare of LED road lighting and clarified similarities of and differences in discomfort glare between LED and traditional light sources.
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 1094-4087 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number IDA @ john @ Serial 351
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Author Vaaja, M.; Kurkela, M.; Virtanen, J.-P.; Maksimainen, M.; Hyyppä, H.; Hyyppä, J.; Tetri, E.
Title Luminance-Corrected 3D Point Clouds for Road and Street Environments Type Journal Article
Year 2015 Publication Remote Sensing Abbreviated Journal Remote Sensing
Volume 7 Issue 9 Pages (down) 11389-11402
Keywords Lighting
Abstract
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 2072-4292 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number LoNNe @ kyba @ Serial 1258
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Author Long, X.; Tie, X.; Zhou, J.; Dai, W.; Li, X.; Feng, T.; Li, G.; Cao, J.; An, Z.
Title Impact of the Green Light Program on haze in the North China Plain, China Type Journal Article
Year 2019 Publication Atmospheric Chemistry and Physics Abbreviated Journal Atmos. Chem. Phys.
Volume 19 Issue 17 Pages (down) 11185-11197
Keywords Economics; Lighting; Planning
Abstract As the world's largest developing country, China has undergone ever-increasing demand for electricity during the past few decades. In 1996, China launched the Green Light Program (GLP), which became a national energy conservation activity for saving lighting electricity as well as an effective reduction of the coal consumption for power generation. Despite the great success of the GLP, its effects on haze have not been investigated and well understood. This study focused on assessing the potential coal saving induced by the improvement of luminous efficacy, the core of the GLP, and on estimating the consequent effects on the haze in the North China Plain (NCP), where a large number of power plants are located and are often engulfed by severe haze. The estimated potential coal saving induced by the GLP can reach a massive value of 120–323 million tons, accounting for 6.7 %–18.0 % of the total coal consumption for thermal power generation in China. There was a massive potential emission reduction of air pollutants from thermal power generation in the NCP, which was estimated to be 20.0–53.8 Gg for NOx and 6.9–18.7 Gg for SO2 in December 2015. The potential emission reduction induced by the GLP plays important roles in the haze formation, because the NOx and SO2 are important precursors for the formation of particles. To assess the impact of the GLP on haze, sensitivity studies were conducted by applying a regional chemical–dynamical model (WRF-CHEM). The model results suggest that in the case of lower-limit emission reduction, the PM2.5 concentration decreased by 2–5 µg m−3 in large areas of the NCP. In the case of upper-limit emission reduction, there was much more remarkable decrease in PM2.5 concentration (4–10 µg m−3). This study is a good example to illustrate that scientific innovation can induce important benefits for environment issues such as haze.
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Publisher Place of Publication Editor
Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1680-7324 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2671
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Author Jeong, S.W.; Park, S.; Jin, J.S.; Seo, O.N.; Kim, G.-S.; Kim, Y.-H.; Bae, H.; Lee, G.; Kim, S.T.; Lee, W.S.; Shin, S.C.
Title Influences of four different light-emitting diode lights on flowering and polyphenol variations in the leaves of chrysanthemum (Chrysanthemum morifolium) Type Journal Article
Year 2012 Publication Journal of Agricultural and Food Chemistry Abbreviated Journal J Agric Food Chem
Volume 60 Issue 39 Pages (down) 9793-9800
Keywords Chrysanthemum/*chemistry/growth & development/metabolism/radiation effects; Flowers/chemistry/*growth & development/metabolism; Light; Plant Leaves/*chemistry/growth & development/metabolism/*radiation effects; Polyphenols/*analysis/metabolism; LED; light emitting diode; lighting
Abstract Light-emitting diodes (LEDs) are an efficient alternative to traditional lamps for plant growth. To investigate the influence of LEDs on flowering and polyphenol biosynthesis in the leaves of chrysanthemum, the plants were grown under supplemental blue, green, red, and white LEDs. Flower budding was formed even after a longer photoperiod than a critical day length of 13.5 h per day under blue light illumination. The weights of leaves and stems were highest under the white light illumination growth condition, whereas the weight of roots appeared to be independent of light quality. Among nine polyphenols characterized by high-performance liquid chromatography-tandem mass spectroscopy, three polyphenols were identified for the first time in chrysanthemum. A quantitation and principal component analysis biplot demonstrated that luteolin-7-O-glucoside (2), luteolin-7-O-glucuronide (3), and quercetagetin-trimethyl ether (8) were the highest polyphenols yielded under green light, and dicaffeoylquinic acid isomer (4), dicaffeoylquinic acid isomer (5), naringenin (7), and apigenin-7-O-glucuronide (6) were greatest under red light. Chlorogenic acid (1) and 1,2,6-trihydroxy-7,8-dimethoxy-3-methylanthraquinone (9) were produced in similar concentrations under both light types. The white and blue light appeared inefficient for polyphenol production. Taken together, our results suggest that the chrysanthemum flowering and polyphenol production are influenced by light quality composition.
Address Department of Chemistry and Research Institute of Life Science, Gyeongsang National University , Jinju, 660-701, Republic of Korea
Corporate Author Thesis
Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0021-8561 ISBN Medium
Area Expedition Conference
Notes PMID:22970652 Approved no
Call Number IDA @ john @ Serial 26
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