|   | 
Details
   web
Records
Author Souman, J.L.; Borra, T.; de Goijer, I.; Schlangen, L.J.M.; Vlaskamp, B.N.S.; Lucassen, M.P.
Title Spectral Tuning of White Light Allows for Strong Reduction in Melatonin Suppression without Changing Illumination Level or Color Temperature Type Journal Article
Year (down) 2018 Publication Journal of Biological Rhythms Abbreviated Journal J Biol Rhythms
Volume 33 Issue 4 Pages 420-431
Keywords Human Health; Lighting
Abstract Studies with monochromatic light stimuli have shown that the action spectrum for melatonin suppression exhibits its highest sensitivity at short wavelengths, around 460 to 480 nm. Other studies have demonstrated that filtering out the short wavelengths from white light reduces melatonin suppression. However, this filtering of short wavelengths was generally confounded with reduced light intensity and/or changes in color temperature. Moreover, it changed the appearance from white light to yellow/orange, rendering it unusable for many practical applications. Here, we show that selectively tuning a polychromatic white light spectrum, compensating for the reduction in spectral power between 450 and 500 nm by enhancing power at even shorter wavelengths, can produce greatly different effects on melatonin production, without changes in illuminance or color temperature. On different evenings, 15 participants were exposed to 3 h of white light with either low or high power between 450 and 500 nm, and the effects on salivary melatonin levels and alertness were compared with those during a dim light baseline. Exposure to the spectrum with low power between 450 and 500 nm, but high power at even shorter wavelengths, did not suppress melatonin compared with dim light, despite a large difference in illuminance (175 vs. <5 lux). In contrast, exposure to the spectrum with high power between 450 and 500 nm (also 175 lux) resulted in almost 50% melatonin suppression. For alertness, no significant differences between the 3 conditions were observed. These results open up new opportunities for lighting applications that allow for the use of electrical lighting without disturbance of melatonin production.
Address Philips Lighting Research, Department Lighting Applications, Eindhoven, The Netherlands
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 0748-7304 ISBN Medium
Area Expedition Conference
Notes PMID:29984614 Approved no
Call Number GFZ @ kyba @ Serial 1985
Permanent link to this record
 

 
Author Yao, Q.; Wang, H.; Uttley, J.; Zhuang, X.
Title Illuminance Reconstruction of Road Lighting in Urban Areas for Efficient and Healthy Lighting Performance Evaluation Type Journal Article
Year (down) 2018 Publication Applied Sciences Abbreviated Journal Applied Sciences
Volume 8 Issue 9 Pages 1646
Keywords Instrumentation; Lighting; Planning
Abstract Big lighting data are required for evaluation of lighting performance and impacts on human beings, environment, and ecology for smart urban lighting. However, traditional approaches of measuring road lighting cannot achieve this aim. We propose a rule-of-thumb model approach based on some feature points to reconstruct road lighting in urban areas. We validated the reconstructed illuminance with both software simulated and real road lighting scenes, and the average error is between 6 and 19%. This precision is acceptable in practical applications. Using this approach, we reconstructed the illuminance of three real road lighting environments in a block and further estimated the mesopic luminance and melanopic illuminance performance. In the future, by virtue of Geographic Information System technology, the approach may provide big lighting data for evaluation and analysis, and help build smarter urban lighting.
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 2076-3417 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2003
Permanent link to this record
 

 
Author Du, J.; Zhang, X.; King, D.
Title An investigation into the risk of night light pollution in a glazed office building: The effect of shading solutions Type Journal Article
Year (down) 2018 Publication Building and Environment Abbreviated Journal Building and Environment
Volume 145 Issue Pages 243-259
Keywords Lighting; Planning
Abstract Light pollution has been recognised as a major environmental problem in urban areas at night. This study presents an investigation into the impact of seven various shading solutions on the risk of light pollution caused by indoor artificial lighting in a fully glazed office building. Radiance, a ray-tracing package, was adopted to calculate external illuminances produced by indoor lighting applications at various positions. It has been determined that: 1) A glazed façade could become a critical source of light pollution or obtrusive light (sky glow and light trespass) due to applications of indoor lighting at night; 2) A light shelf could perform well on the protection of both light trespass and sky glow; 3) A large overhang and horizontal louvre could effectively lower the risk of light trespass, but would possibly cause the deterioration of sky glow; and 4) No significant impact of short overhang and vertical louvre can be found on the two aspects of light pollution. This study exposes a significant implication; apart from their principal functions, the shading devices applied in a largely glazed building may require a new role in controlling obtrusive light in cities at night.
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 0360-1323 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2015
Permanent link to this record
 

 
Author Beccali, M.; Bonomolo, M.; Leccese, F.; Lista, D.; Salvadori, G.
Title On the impact of safety requirements, energy prices and investment costs in street lighting refurbishment design Type Journal Article
Year (down) 2018 Publication Energy Abbreviated Journal Energy
Volume in press Issue Pages in press
Keywords Lighting; Economics; Energy; Planning
Abstract Street lighting is an indispensable feature for the night landscape of cities. It is important for road safety, users visual comfort, crime prevention and to augment the perceived personal safety. Realize and maintain an adequate street lighting service is very expensive for municipalities with significant impact on their budgets. For this reason, special attention should be paid to the design of new street lighting systems and to the refurbishment of existing ones, since many of them are inadequate. In light of this it is very important to implement street lighting designs that fulfil lighting requirements avoiding energy waste and light pollution and, at the same time, result economically sustainable for municipalities. In this paper, an original step by step methodology for the lighting, energy and economic analysis of street lighting refurbishment designs has been introduced and explained in detail. The methodology is suitable for use in cities of different sizes. As an applicative example, the methodology has been tested in the town of Pontedera (Italy) and the results are discussed, also providing a sensitivity analysis of the economic feasibility with respect to the variations of electricity prices and investment costs.
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 0360-5442 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2020
Permanent link to this record
 

 
Author Babadi, S.; Ramirez-Inguiez, R.; Boutaleb, T.; Mallick, T.
Title Producing uniform illumination within a rectangular area by using a nonimaging optic Type Journal Article
Year (down) 2018 Publication Applied Optics Abbreviated Journal Appl. Opt.
Volume 57 Issue 31 Pages 9357
Keywords Lighting
Abstract This paper proposes a new design method to create a novel optical element to generate uniform illumination within a rectangular area. Based on this model, an illuminated area is irradiated by two sets of rays; the first one irradiates the target plane after refraction from the top section of the lens, and the second one irradiates from the reflection at the side profile of the lens and then from refraction at the top part of the lens. The results show that a uniformity of over 90% can be achieved.
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 1559-128X ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2046
Permanent link to this record