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Author Chen, S.; Li, W.; Yang, S.; Zhang, B.; Li, T.; Du, Y.; Yang, M.; Zhao, H. url  doi
openurl 
  Title Evaluation method and reduction measures for the flicker effect in road lighting using fixed Low Mounting Height Luminaires Type Journal Article
  Year 2019 Publication (down) Tunnelling and Underground Space Technology Abbreviated Journal Tunnelling and Underground Space Technology  
  Volume 93 Issue Pages 103101  
  Keywords Lighting; Vision  
  Abstract Low Mounting Height Luminaires (LMHL) are used in many cities on viaducts, cross-sea and cross-river bridges due to their unique advantages. However, the flicker effect is an important factor that needs to be considered in road lighting using fixed LMHL. At present, there are not many researchers in the field of international lighting. Previous types of road lighting design were based on the method of the tunnel lighting flicker effect. At the same time, the flicker effect is mainly based on the subjective feelings of people but is not quantified. In this paper, the Flicker Index (FI) is calculated by measuring the parameters of streetlamps to evaluation flicker effect. Secondly, the suggestion to offset the flicker effect in CIE 88-2004 “Guide for the Lighting of Road Tunnels and Underpasses” is to limit the speed of the vehicle and adjust the road light spacing to avoid the flicker sensitive area on human eyes, while ignoring the essential problem of how the flicker effect is generated through the energy level of the stimulating optical signal. Two factors affecting the strength of the flicker effect are proposed: energy ratio and duty cycle. The duty cycle, in time, refers to the proportion of the strong and weak flashing signals during the period; in space, it refers to the proportional relationship between the length of the luminaire and the distance between the lamps, which is related to the running speed of the vehicle. It is consistent with the CIE recommendations for flicker. Thirdly, the essence of the flicker effect is the problem of the energy level of the stimulus signal. This study investigated the reduction in the brightness of the light source, hence reducing the energy of the visual stimulation signal to the human eye in order to judge the degree of fatigue in human vision. The experimental results show that the degree of fatigue in human vision decreases when the brightness of the experimental light source decreases. Therefore, the key to changing the flicker effect of LMHL is to reduce the contrast between the surface brightness of the luminaire and the brightness of the spatial background.  
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  ISSN 0886-7798 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2663  
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Author Huffeldt, N.P. url  doi
openurl 
  Title Photic Barriers to Poleward Range-shifts Type Journal Article
  Year 2020 Publication (down) Trends in Ecology & Evolution Abbreviated Journal Trends Ecol Evol  
  Volume in press Issue Pages  
  Keywords Animals; biological rhythm; global climate change; phenology; photoperiod; photoreception; range-shift  
  Abstract With climate warming, organisms are shifting their ranges towards the poles, tracking their optimal thermal environments. Day-length, the driver of daily and annual timing, is, however, fixed by latitude and date. Timing and photoreception mechanisms adapted to ancestral photic environments may restrict range-shift capacity, resulting in photic barriers to range-shifts.  
  Address Greenland Institute of Natural Resources, 3900 Nuuk, Greenland; Arctic Ecosystem Ecology, Department of Bioscience, Aarhus University, 4000 Roskilde, Denmark. Electronic address: nph@bios.au.dk  
  Corporate Author Thesis  
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  Language English Summary Language Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0169-5347 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:32473743 Approved no  
  Call Number GFZ @ kyba @ Serial 2992  
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Author Brelsford, CC; Robson, TM url  doi
openurl 
  Title Blue light advances bud burst in branches of three deciduous tree species under short-day conditions Type Journal Article
  Year 2018 Publication (down) 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.  
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  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 1847  
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Author Tinus, R. W. url  openurl
  Title Effects of Extended Photoperiod on Southern Rocky Mountain Engelmann Spruce and Douglas-fir Type Journal Article
  Year 1981 Publication (down) Tree Planters' Notes Abbreviated Journal  
  Volume 32 Issue 4 Pages  
  Keywords Plants  
  Abstract Four sources of Engelmann spruce and two of Douglas-fir were grown under eight different extended photoperiod regimes. Incandescent light 1 minute of every 15 at night at 270 lux was more effective than continuous incandescent at 1200 lux or intermittent fluorescent at 950 lux at preventing bud dormancy and maintaining continuous height growth.  
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  Call Number IDA @ intern @ Serial 2368  
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Author Barrette, T.P.; Pike, A.M. url  doi
openurl 
  Title Closed-Course Human Factors Evaluation of Marking and Marker Visibility Type Journal Article
  Year 2019 Publication (down) Transportation Research Record: Journal of the Transportation Research Board Abbreviated Journal Transportation Research Record  
  Volume 2673 Issue 10 Pages 840-849  
  Keywords Vision; Transportation; Raised retroreflective pavement markers; retroreflectivity  
  Abstract Raised retroreflective pavement markers (RRPMs) are commonly used to provide nighttime delineation of roadways. Although RRPMs are visible during dry conditions, they provide their greatest benefit during wet-night conditions, when typical pavement markings become flooded and lose their retroreflectivite properties. Naturally, the retroreflectivity of RRPMs degrades over time as a result of traffic, ultraviolet light, precipitation, and roadway maintenance activities. Subsequently, it is necessary to examine the relationship between driver performance and the condition of the RRPMs. To assess visibility relative to RRPM condition, study participants rode in the passenger seat of a vehicle operated by a member of the research team, traveling at approximately 15 mph, for two laps around a closed course. Throughout each lap of the course, nine treatments consisting of RRPMs or preformed pavement marking tape of various retroreflectivity levels diverged from a center line to either the right or left. Participants indicated when they could tell which direction the treatment diverged, which was recorded using a GPS unit. A generalized linear model was estimated on a dataset constructed by pairing the observed distances from various treatments with demographic information about each participant. The analysis indicates the distance at which a particular treatment would be visible, which can then be converted to preview time to assess treatment adequacy for a variety of speeds. The RRPM treatments generally provided adequate preview time for older drivers based on the extant literature; however, the preformed pavement marking tape was less adequate at higher speeds and under overhead lighting.  
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  ISSN 0361-1981 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2499  
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