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Author (up) Bierman, A. url  doi
openurl 
  Title Will switching to LED outdoor lighting increase sky glow? Type Journal Article
  Year 2012 Publication Lighting Research and Technology Abbreviated Journal Lighting Research and Technology  
  Volume 44 Issue 4 Pages 449-458  
  Keywords LED; light emitting diode; skyglow; light pollution; modeling; Radiative transfer  
  Abstract As LED sources are increasingly being used for outdoor lighting, concerns are being raised about their impact on man-made sky glow. This paper compares the amount of light scattered back to Earth from a 6500 K phosphor-converted white LED light source to that from a 2050 K high pressure sodium (HPS) light source. Calculations based solely on molecular Rayleigh scattering provide an upper limit of 22% more scatter from the LED source, but are not realistic because the atmosphere has significant scatter from aerosol content. Adding in the effects of aerosols in the atmosphere, as derived from aerosol optical depth measurements and Mie scattering distributions, reduces the wavelength dependency of scattered light to where the LED source has roughly 10–20% more scattered light contributing to sky glow. Scattering ratios (LED:HPS) are calculated for different angles and atmospheric conditions.  
  Address Lighting Research Center, 21 Union Street, Troy, NY 12180-3352, USA; bierma2(at)rpi.edu  
  Corporate Author Thesis  
  Publisher SAGE Place of Publication Editor  
  Language English Summary Language English Original Title  
  Series Editor Series Title Abbreviated Series Title  
  Series Volume Series Issue Edition  
  ISSN 1477-1535 ISBN Medium  
  Area Expedition Conference  
  Notes Luginbuhl, Boley, and Davis (2013) dispute Bierman's thesis. Approved no  
  Call Number IDA @ john @ Serial 269  
Permanent link to this record
 

 
Author (up) Bierman, A.; Figueiro, M.G.; Rea, M.S. url  doi
openurl 
  Title Measuring and predicting eyelid spectral transmittance Type Journal Article
  Year 2011 Publication Journal of Biomedical Optics Abbreviated Journal J Biomed Opt  
  Volume 16 Issue 6 Pages 067011  
  Keywords Instrumentation; Human Health  
  Abstract The purpose of the present study was to objectively quantify the spectral transmittance of the eyelid. Reported here are data acquired using a technique that was developed to provide practical and accurate measurements of eyelid transmittance across the visible portion of the electromagnetic spectrum. The empirical data were analyzed in terms of the absorption and scattering characteristics of the constituents of skin to develop a method for predicting eyelid transmission. Results showed that the eyelid has a much higher optical density at short wavelengths than previously published. The mean +/- standard deviation (s.d.) optical density of the eyelid from 450 to 650 nm was 2.1 +/- 0.3 with an optical density range among subjects of approximately 1.0. The study results indicate that skin pigmentation is poorly correlated with eyelid transmission; eyelid transmission is most affected by wavelength-independent macromolecules in the eyelid as well as its overall thickness.  
  Address Rensselaer Polytechnic Institute, Lighting Research Center, 21 Union Street, Troy, New York 12180, USA  
  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 1083-3668 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:21721832 Approved no  
  Call Number LoNNe @ kyba @ Serial 1530  
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Author (up) Bullough, J.D.; Bierman, A.; Rea, M.S. url  doi
openurl 
  Title Evaluating the Blue-Light Hazard from Solid State Lighting Type Journal Article
  Year 2017 Publication International Journal of Occupational Safety and Ergonomics : JOSE Abbreviated Journal Int J Occup Saf Ergon  
  Volume 25 Issue 2 Pages 311-320  
  Keywords Human Health  
  Abstract Purpose New light sources including light emitting diodes (LEDs) have elicited questions about retinal damage, including the blue-light hazard. Some organizations have recommended avoiding using LEDs with correlated color temperatures (CCTs) exceeding 3000 K, since they tend to produce greater short-wavelength energy. This paper provides quantitative comparisons among light sources and use cases as they affect blue-light hazard. Methods The spectral radiant power characteristics of incandescent, fluorescent, LED and daylight sources were evaluated in terms of blue-light hazard using standard procedures for phakic, aphakic and pseudophakic eyes. Results Under most use cases, LEDs do not exhibit greater risk for blue-light hazard than other sources (e.g., incandescent). Because they generally produce little-to-no ultraviolet energy, LEDs often present less risk to aphakic eyes. Conclusions LEDs present no special concerns for blue-light hazard over some other common sources in typical use cases because photophobic responses limit exposure to bright sources. Where photophobic responses might not occur (e.g., eye surgery patients or premature infants) or where individuals suppress these responses (e.g., stage actors), caution is necessary. Evidence remains inconsistent regarding the risk of human retinal damage from long-term exposures to light insufficient to reach acute blue-light hazard thresholds.  
  Address a Lighting Research Center , Rensselaer Polytechnic Institute , US  
  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 1080-3548 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:28876164 Approved no  
  Call Number LoNNe @ kyba @; GFZ @ kyba @ Serial 1720  
Permanent link to this record
 

 
Author (up) Figueiro, M.G.; Bierman, A.; Plitnick, B.; Rea, M.S. url  doi
openurl 
  Title Preliminary evidence that both blue and red light can induce alertness at night Type Journal Article
  Year 2009 Publication BMC Neuroscience Abbreviated Journal BMC Neurosci  
  Volume 10 Issue Pages 105  
  Keywords Adult; Alpha Rhythm; Analysis of Variance; Beta Rhythm; Circadian Rhythm/*physiology; Cornea/physiology; Dose-Response Relationship, Radiation; Electrocardiography; Female; Humans; *Light; Male; Melatonin/secretion; Middle Aged; *Photic Stimulation; Psychomotor Performance; Radioimmunoassay; Salivary Glands/secretion; Wakefulness/*physiology; physiology of vision; blue light; red light  
  Abstract BACKGROUND: A variety of studies have demonstrated that retinal light exposure can increase alertness at night. It is now well accepted that the circadian system is maximally sensitive to short-wavelength (blue) light and is quite insensitive to long-wavelength (red) light. Retinal exposures to blue light at night have been recently shown to impact alertness, implicating participation by the circadian system. The present experiment was conducted to look at the impact of both blue and red light at two different levels on nocturnal alertness. Visually effective but moderate levels of red light are ineffective for stimulating the circadian system. If it were shown that a moderate level of red light impacts alertness, it would have had to occur via a pathway other than through the circadian system. METHODS: Fourteen subjects participated in a within-subject two-night study, where each participant was exposed to four experimental lighting conditions. Each night each subject was presented a high (40 lx at the cornea) and a low (10 lx at the cornea) diffuse light exposure condition of the same spectrum (blue, lambda(max) = 470 nm, or red, lambda(max) = 630 nm). The presentation order of the light levels was counterbalanced across sessions for a given subject; light spectra were counterbalanced across subjects within sessions. Prior to each lighting condition, subjects remained in the dark (< 1 lx at the cornea) for 60 minutes. Electroencephalogram (EEG) measurements, electrocardiogram (ECG), psychomotor vigilance tests (PVT), self-reports of sleepiness, and saliva samples for melatonin assays were collected at the end of each dark and light periods. RESULTS: Exposures to red and to blue light resulted in increased beta and reduced alpha power relative to preceding dark conditions. Exposures to high, but not low, levels of red and of blue light significantly increased heart rate relative to the dark condition. Performance and sleepiness ratings were not strongly affected by the lighting conditions. Only the higher level of blue light resulted in a reduction in melatonin levels relative to the other lighting conditions. CONCLUSION: These results support previous findings that alertness may be mediated by the circadian system, but it does not seem to be the only light-sensitive pathway that can affect alertness at night.  
  Address Lighting Research Center, Rensselaer Polytechnic Institute, Troy, NY, USA. figuem@rpi.edu  
  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 1471-2202 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:19712442; PMCID:PMC2744917 Approved no  
  Call Number IDA @ john @ Serial 285  
Permanent link to this record
 

 
Author (up) He, Y.; Rea, M.; Bierman, A.; Bullough, J. url  doi
openurl 
  Title Evaluating Light Source Efficacy under Mesopic Conditions Using Reaction Times Type Journal Article
  Year 1997 Publication Journal of the Illuminating Engineering Society Abbreviated Journal Journal of the Illuminating Engineering Society  
  Volume 26 Issue 1 Pages 125-138  
  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 0099-4480 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number LoNNe @ kagoburian @ Serial 634  
Permanent link to this record
 

 
Author (up) Rea, M. S.; Bierman, A. url  openurl
  Title Spectral considerations for outdoor lighting: Consequences for sky glow Type Journal Article
  Year 2014 Publication Lighting Research and Technology Abbreviated Journal Lighting Res. & Tech.  
  Volume 47 Issue 8 Pages 920-930  
  Keywords Lighting; skyglow; spectrum; scattering; aerosol; modeling  
  Abstract It is well known that the magnitude of sky glow on a clear night depends upon the aerosol content in the atmosphere and the spectral power distribution (amount and spectrum). Sources with a greater proportion of short-wavelength radiation produce more backscattered radiation, but as aerosol density increases, the differential effect of spectrum becomes smaller. Sky glow magnitude also depends upon the operating characteristics of the detector and will be greater when the spectrum of the backscattered radiation is tuned to the spectral band-pass characteristics of the detector. The human visual system is most often used to assess sky glow magnitude, but its spectral response is not limited to a single, univariate detector. Rather, the retina is composed of many neural channels, each with its own spectral and absolute sensitivities to optical radiation. Since we can use a different neural channel to see an individual star than we do to gain an overall impression of sky brightness, changes to the spectral power distribution of backscattered radiation differentially, and simultaneously, affect one’s ability to see a single star and to assess sky brightness. A general method for assessing sky glow based upon aerosol content, spectral power distribution and the specific operating characteristics of a detector, human or otherwise, is offered.  
  Address Lighting Research Center, Rensselaer Polytechnic Institute, Troy, New York, USA  
  Corporate Author Thesis  
  Publisher The Society of Light and Lighting 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 IDA @ john @ Serial 1065  
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