toggle visibility Search & Display Options

Select All    Deselect All
 |   | 
Details
   print
  Records Links
Author Kocifaj, M. url  doi
openurl 
  Title Modeling the night-sky radiances and inversion of multi-angle and multi-spectral radiance data Type Journal Article
  Year 2014 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer  
  Volume (down) 139 Issue Pages 35-42  
  Keywords Sky-glow; Light pollution; Aerosols; Light scattering; Inverse problems  
  Abstract Information on a city's emission pattern is crucial for any reasonable predictions of night sky radiances. Unfortunately, the bulk radiant intensity distribution as a function of zenith angle is scarcely available for any city throughout the world. Even if the spatial arrangements of urban light fixtures and lamp specifications are known, the cumulative effect on upwardly directed beams is difficult to determine; due to heterogeneity of the ambient environment, reflectance from ground surfaces, arbitrarily scattered obstacles, orography of terrain and many other site specific factors.

The present paper develops a theoretical model and a numerical technique applicable to the retrieval of a City Emission Function (CEF) from the spectral sky radiances measured under clear sky conditions. Mathematically it is an inverse problem that is solved using a regularization algorithm in which the minimization routines penalize non-smooth solutions and the radiant intensity pattern is found subject to regularizing constraints.

When spectral sky radiances are measured at a set of discrete wavelengths or at a set of discrete distances from the monitored light source, both the aerosol optical properties and the CEF can be determined concurrently. One great advantage of this approach is that no a-priori assumptions need to be made concerning aerosol properties, such as aerosol optical depth.

The numerical experiment on synthetically generated city emissions' patterns has proven the functionality of the method presented.
 
  Address ICA, Slovak Academy of Sciences, Dúbravská Road 9, 845 03 Bratislava, Slovakia.  
  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 0022-4073 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 180  
Permanent link to this record
 

 
Author Sánchez de Miguel, A.; Zamorano, J.; Gómez Castaño, J.; Pascual, S. url  doi
openurl 
  Title Evolution of the energy consumed by street lighting in Spain estimated with DMSP-OLS data Type Journal Article
  Year 2014 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal Journal of Quantitative Spectroscopy and Radiative Transfer  
  Volume (down) 139 Issue Pages 109-117  
  Keywords Light pollution; Power consumption; Remote sensing; Light pollution models; Spain  
  Abstract We present the results of the analysis of satellite imagery to study light pollution in Spain. Both calibrated and non-calibrated DMSP-OLS images were used. We describe the method to scale the non-calibrated DMSP-OLS images which allows us to use differential photometry techniques in order to study the evolution of the light pollution. Population data and DMSP-OLS satellite calibrated images for the year 2006 were compared to test the reliability of official statistics in public lighting consumption. We found a relationship between the population and the energy consumption which is valid for several regions. Finally the true evolution of the electricity consumption for street lighting in Spain from 1992 to 2010 was derived; it has been doubled in the last 18 years in most of the provinces.  
  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 0022-4073 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 187  
Permanent link to this record
 

 
Author Fiorentin, P.; Boscaro, F. url  doi
openurl 
  Title A method for measuring the light output of video advertising reproduced by LED billboards Type Journal Article
  Year 2019 Publication Measurement Abbreviated Journal Measurement  
  Volume (down) 138 Issue Pages 25-33  
  Keywords Lighting; Energy; Instrumentation; Planning; Light-emitting diode displays; Photometry; Video recording; Image analysis; CCD image sensors; Luminance; Glare  
  Abstract Improving knowledge of the light output of digital billboards is important to better assess their effect on driver distraction when they are installed along roads. In this work the emission of an LED based billboard is measured when playing advertising video-clips. In particular the average and the maximum values of the luminance are evaluated. The same video-clips are also analyzed when shown on an LCD monitor, aiming at separating the variability of the videos and of the playing device. The results allow to evaluate an utilization factor of the billboard: the videos have an average luminance around 11% and a peak luminance of 35% of the maximum luminance obtainable from the billboard. The power consumption of the billboard is measured, aside the photometric analysis. The luminance of the device are found linearly dependent on both the power and the effective current absorbed by the device from the grid, with a discrepancy within 6%. It could be a useful information for billboard manufacturers to qualify their product when they do not own photometric instruments.  
  Address Department of Industrial Engineering, University of Padova, Padova, Italy; pietro.fiorentin(at)unipd.it  
  Corporate Author Thesis  
  Publisher Elsevier Place of Publication Editor  
  Language English Summary Language English Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 0263-2241 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2214  
Permanent link to this record
 

 
Author BjÖRnberg, T.K.S.; Wilbur, K.M. url  doi
openurl 
  Title Copepod Phototaxis And Vertical Migration Influenced By Xanthene Dyes Type Journal Article
  Year 1968 Publication The Biological Bulletin Abbreviated Journal The Biological Bulletin  
  Volume (down) 134 Issue 3 Pages 398-410  
  Keywords Animals  
  Abstract 1. Phototaxis of the copepods Paracalanus crassirostris, Calanopia americana, and Acartia lillijeborgi has been measured by determining the percentage of a population moving toward or away from a point source of light per unit time. Quantitative differences in positive phototaxis were found between the species. Photopositive responses differed during the day and night in Acartia but not in Paracalanus and Calanopia.

2. Rhodamine B (8.4 x 10-6 M) brought about the following effects: (a) Locomotor activity was reversibly inhibited in all species. (b) Photopositive responses were increased in Calanopia and Acartia but decreased in Paracalanus. (c) The difference between day and night responses to a point source of light was abolished in Acartia and induced in Calanopia. (d) Somersaulting was induced in Paracalanus but not in the other species.

3. Pyronine B (8.4 x 10-6 M) also decreased locomotor activity. Fluorescein sodium (1.1 x 10-5 M and 1.1 x 10-4 M) was without significant effect.

4. Paracalanus, Calanopia, and Acartia exhibited characteristically distinct diurnal migratory cycles in vertical cylinders, which correlated well with behavior in natural waters. Calanopia and Acartia migrated to the bottom in the daylight whereas Paracalanus and young forms of Acartia were widely distributed vertically during daylight. Specimens of Calanopia and Acartia kept in the dark did not migrate.

5. The effects of rhodamine B (8.4 x 10-6 M) on vertical migration depended upon species, developmental stage, and time of day. In general, rhodamine increased the concentration of animals at the surface at night and at the bottom in daylight. Fluorescein sodium (1.1 x 10-5 M and 1.1 x 10-4 M) had little effect on vertical migration.

6. The effectiveness of rhodamine B and pyronine B is probably related to the presence of diethylamine groups lacking in fluorescein.
 
  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 0006-3185 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2469  
Permanent link to this record
 

 
Author Zhu, X.; Guo, X.; Zhang, J.; Liu, J.; Jiang, F. url  doi
openurl 
  Title Phosphor-free, color-mixed, and efficient illuminant: Multi-chip packaged LEDs for optimizing blue light hazard and non-visual biological effects Type Journal Article
  Year 2020 Publication Optics and Lasers in Engineering Abbreviated Journal Optics and Lasers in Engineering  
  Volume (down) 134 Issue Pages 106174  
  Keywords Lighting; Human Health  
  Abstract Currently many evaluation models on the photobiological effects (PBE) of light sources do not consider the influence of age and luminance on the pupil diameter, which affects the light radiation intensity on the human retina. In this study, the pupil diameter is taken into consideration when evaluating the PBE of several light sources. Moreover, the correction factor M is proposed. The blue light hazard (BLH) efficacy and the circadian rhythm (CR) effects of the daylight at dusk, together with three indoor light sources with a correlated color temperature (CCT) of about 3000 K were evaluated by using a corrected evaluation model. The results show that an incandescent lamp is more photobiologically friendly for humans, despite being inefficient. Based on high wall-plug efficiency (WPE) GaN-based yellow (565 nm, 24.3%@20 A/cm2) and green (522 nm, 41.3%@20 A/cm2) LEDs on silicon substrate, incandescent-like spectrum and phosphor-free color-mixed white LEDs (CM-LEDs) with a general color rendering index (CRI) of 94, a CCT of 2866 K, and an efficiency of 131 lm/W were manufactured by mixing blue, cyan, green, yellow and red LEDs. The PBE evaluation results of such CM-LEDs are superior to those of an incandescent lamp. Moreover, blue light free and candlelight-toned LEDs with an efficiency of 120.3 lm/W, a general CRI of 84, a special CRI R9 of 93.3, and a CCT of 1810 K were fabricated by mixing yellow and red LEDs (R&Y-mixed LEDs). The R&Y-mixed LEDs show no blue light weighted quantities and have a weaker influence on the CR shift. They are photobiologically friendly for humans and suitable for nocturnal indoor and outdoor lighting environments.  
  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 0143-8166 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2983  
Permanent link to this record
Select All    Deselect All
 |   | 
Details
   print

Save Citations:
Export Records: