|   | 
Details
   web
Records
Author Bullough, J.D.; Donnell, E.T.; Rea, M.S.
Title To illuminate or not to illuminate: roadway lighting as it affects traffic safety at intersections Type Journal Article
Year 2013 Publication Accident; Analysis and Prevention Abbreviated Journal Accid Anal Prev
Volume 53 Issue Pages 65-77
Keywords Lighting; Accident Prevention/*methods; Accidents, Traffic/*prevention & control/psychology/statistics & numerical data; Cross-Sectional Studies; *Environment Design; Humans; *Lighting; Minnesota; Models, Statistical; Photoperiod; Psychomotor Performance; Regression Analysis; Safety/statistics & numerical data; Visual Perception
Abstract A two-pronged effort to quantify the impact of lighting on traffic safety is presented. In the statistical approach, the effects of lighting on crash frequency for different intersection types in Minnesota were assessed using count regression models. The models included many geometric and traffic control variables to estimate the association between lighting and nighttime and daytime crashes and the resulting night-to-day crash ratios. Overall, the presence of roadway intersection lighting was found to be associated with an approximately 12% lower night-to-day crash ratio than unlighted intersections. In the parallel analytical approach, visual performance analyses based on roadway intersection lighting practices in Minnesota were made for the same intersection types investigated in the statistical approach. The results of both approaches were convergent, suggesting that visual performance improvements from roadway lighting could serve as input for predicting improvements in crash frequency. A provisional transfer function allows transportation engineers to evaluate alternative lighting systems in the design phase so selections based on expected benefits and costs can be made.
Address Lighting Research Center, Rensselaer Polytechnic Institute, 21 Union Street, Troy, NY 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 0001-4575 ISBN Medium
Area Expedition Conference
Notes (down) PMID:23377085 Approved no
Call Number LoNNe @ kagoburian @ Serial 627
Permanent link to this record
 

 
Author Zukauskas, A.; Vaicekauskas, R.; Vitta, P.
Title Optimization of solid-state lamps for photobiologically friendly mesopic lighting Type Journal Article
Year 2012 Publication Applied Optics Abbreviated Journal Appl Opt
Volume 51 Issue 35 Pages 8423-8432
Keywords Lighting Systems; Circadian Rhythm; Color; Equipment Design; Humans; Light; *Lighting; Melatonin/metabolism; Photobiology/*methods; Semiconductors; Time Factors; Vision, Ocular
Abstract The circadian and visual-performance-based mesopic systems of photometry were applied for the optimization of the spectral power distributions (SPDs) of the solid-state sources of light for low-illuminance lighting applications. At mesopic adaptation luminances typical of outdoor lighting (0.1-2 cd/m(2)), the optimal SPDs were obtained through the minimization of the mesopic circadian action factor, which is the ratio of the circadian efficacy of radiation to mesopic luminous efficacy of radiation. For correlated color temperatures below ~3000 K, the optimized dichromatic light-emitting diodes (LEDs) are shown to pose a lower circadian hazard than high-pressure sodium lamps and common warm white LEDs; also they are potentially more efficacious and have acceptable color rendition properties under mesopic conditions.
Address Institute of Applied Research, Vilnius University, Sauletekio al. 9-III, Vilnius LT-10222, Lithuania. arturas.zukauskas@ff.vu.lt
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 0003-6935 ISBN Medium
Area Expedition Conference
Notes (down) PMID:23262538 Approved no
Call Number LoNNe @ christopher.kyba @ Serial 448
Permanent link to this record
 

 
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 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 (down) PMID:22970652 Approved no
Call Number IDA @ john @ Serial 26
Permanent link to this record
 

 
Author Elvidge, C.D.; Keith, D.M.; Tuttle, B.T.; Baugh, K.E.
Title Spectral identification of lighting type and character Type Journal Article
Year 2010 Publication Sensors (Basel, Switzerland) Abbreviated Journal Sensors (Basel)
Volume 10 Issue 4 Pages 3961-3988
Keywords Led; Nightsat; lighting efficiency; lighting types; nighttime lights; photopic band
Abstract We investigated the optimal spectral bands for the identification of lighting types and the estimation of four major indices used to measure the efficiency or character of lighting. To accomplish these objectives we collected high-resolution emission spectra (350 to 2,500 nm) for forty-three different lamps, encompassing nine of the major types of lamps used worldwide. The narrow band emission spectra were used to simulate radiances in eight spectral bands including the human eye photoreceptor bands (photopic, scotopic, and “meltopic”) plus five spectral bands in the visible and near-infrared modeled on bands flown on the Landsat Thematic Mapper (TM). The high-resolution continuous spectra are superior to the broad band combinations for the identification of lighting type and are the standard for calculation of Luminous Efficacy of Radiation (LER), Correlated Color Temperature (CCT) and Color Rendering Index (CRI). Given the high cost that would be associated with building and flying a hyperspectral sensor with detection limits low enough to observe nighttime lights we conclude that it would be more feasible to fly an instrument with a limited number of broad spectral bands in the visible to near infrared. The best set of broad spectral bands among those tested is blue, green, red and NIR bands modeled on the band set flown on the Landsat Thematic Mapper. This set provides low errors on the identification of lighting types and reasonable estimates of LER and CCT when compared to the other broad band set tested. None of the broad band sets tested could make reasonable estimates of Luminous Efficacy (LE) or CRI. The photopic band proved useful for the estimation of LER. However, the three photoreceptor bands performed poorly in the identification of lighting types when compared to the bands modeled on the Landsat Thematic Mapper. Our conclusion is that it is feasible to identify lighting type and make reasonable estimates of LER and CCT using four or more spectral bands with minimal spectral overlap spanning the 0.4 to 1.0 um region.
Address Earth Observation Group, Solar and Terrestrial Division, NOAA National Geophysical Data Center, 325 Broadway, Boulder, CO 80305, USA. chris.elvidge@noaa.gov
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 1424-8220 ISBN Medium
Area Expedition Conference
Notes (down) PMID:22319336; PMCID:PMC3274255 Approved no
Call Number IDA @ john @ Serial 275
Permanent link to this record
 

 
Author Vollmer, C.; Michel, U.; Randler, C.
Title Outdoor light at night (LAN) is correlated with eveningness in adolescents Type Journal Article
Year 2012 Publication Chronobiology International Abbreviated Journal Chronobiol Int
Volume 29 Issue 4 Pages 502-508
Keywords Adolescent; *Adolescent Behavior/drug effects; Biological Clocks; Central Nervous System Stimulants/administration & dosage; *Circadian Rhythm/drug effects; Computers; Cross-Sectional Studies; Female; Germany; Humans; *Light; Lighting; Male; *Photic Stimulation; *Photoperiod; Questionnaires; *Sleep/drug effects; Television; Time Factors; Video Games; *Wakefulness/drug effects
Abstract External zeitgebers synchronize the human circadian rhythm of sleep and wakefulness. Humans adapt their chronotype to the day-night cycle, the strongest external zeitgeber. The human circadian rhythm shifts to evening-type orientation when daylight is prolonged into the evening and night hours by artificial light sources. Data from a survey of 1507 German adolescents covering questions about chronotype and electronic screen media use combined with nocturnal satellite image data suggest a relationship between chronotype and artificial nocturnal light. Adolescents living in brightly illuminated urban districts had a stronger evening-type orientation than adolescents living in darker and more rural municipalities. This result persisted when controlling for time use of electronic screen media, intake of stimulants, type of school, age, puberty status, time of sunrise, sex, and population density. Time spent on electronic screen media use-a source of indoor light at night-is also correlated with eveningness, as well as intake of stimulants, age, and puberty status, and, to a lesser degree, type of school and time of sunrise. Adequate urban development design and parents limiting adolescents' electronic screen media use in the evening could help to adjust adolescents' zeitgeber to early school schedules when they provide appropriate lighting conditions for daytime and for nighttime.
Address Department of Biology, University of Education Heidelberg, Germany. vollmer@ph-heidelberg.de
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 0742-0528 ISBN Medium
Area Expedition Conference
Notes (down) PMID:22214237 Approved no
Call Number IDA @ john @ Serial 150
Permanent link to this record