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Author Checa, J.; Nel·lo, O.
Title Urban Intensities. The Urbanization of the Iberian Mediterranean Coast in the Light of Nighttime Satellite Images of the Earth Type Journal Article
Year 2018 Publication Urban Science Abbreviated Journal Urban Science
Volume 2 Issue (down) 4 Pages 115
Keywords Remote Sensing; Tourism
Abstract The contribution shares the approach of critical urban studies that have conceptualized urbanization more as a process than as a sum of spatial forms. Thus, the contribution studies the urbanization process not only from the point of view of the physical occupation of land but also considers changes in the intensity of the uses of space. To fulfill this aim, the new sources of nocturnal satellite images are particularly useful. These allow us to observe the intensity of urban uses both in terms of their distribution over space and their recurrence over time. The research focuses on the Iberian Mediterranean coast and permits the verification of the intensity of the urban uses of the space for the whole of this area and their seasonal variations throughout the year. The source of the study are the nighttime satellite images of the Earth for the 2012–2017 period from the NASA SNPP satellite equipped with the VIIRS-DNB instrument. By establishing a threshold of urban light the research shows that those districts with the greatest extensions of urban light do not necessarily correspond with the most densely populated areas. Similarly the absence of urban light does not necessarily indicate the absence of urban uses. Finally, the variations of intensity of light prove to be a good indicator of seasonal variations of activity in tourist areas.
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 2413-8851 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2120
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Author Sullivan, J.M.; Flannagan, M.J.
Title The role of ambient light level in fatal crashes: inferences from daylight saving time transitions Type Journal Article
Year 2002 Publication Accident Analysis & Prevention Abbreviated Journal Accident Analysis & Prevention
Volume 34 Issue (down) 4 Pages 487-498
Keywords Public Safety; Lighting
Abstract The purpose of this study was to estimate the size of the influence of ambient light level on fatal pedestrian and vehicle crashes in three scenarios. The scenarios were: fatal pedestrian crashes at intersections, fatal pedestrian crashes on dark rural roads, and fatal single-vehicle run-off-road crashes on dark, curved roads. Each scenario's sensitivity to light level was evaluated by comparing the number of fatal crashes across changes to and from daylight saving time, within daily time periods in which an abrupt change in light level occurs relative to official clock time. The analyses included 11 years of fatal crashes in the United States, between 1987 and 1997. Scenarios involving pedestrians were most sensitive to light level, in some cases showing up to seven times more risk at night over daytime. In contrast, single-vehicle run-off-road crashes showed little difference between light and dark time periods, suggesting factors other than light level play the dominant role in these crashes. These results are discussed in the context of the possible safety improvements offered by new developments in adaptive vehicle headlighting.
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Publisher Place of Publication Editor
Language 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 Approved no
Call Number GFZ @ kyba @ Serial 2126
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Author Flannagan, M.J.; Sivak, M.; Traube, E.C.; Kojima, S.
Title Effects of Overall Low-Beam Intensity on Seeing Distance in the Presence of Glare Type Journal Article
Year 2000 Publication Transportation Human Factors Abbreviated Journal Transportation Human Factors
Volume 2 Issue (down) 4 Pages 313-330
Keywords Public Safety; Vision
Abstract Previous studies have demonstrated that current low-beam headlamps do not provide adequate seeing distance for safety. Could this situation be improved by providing more total light from low-beam headlamps, leaving the relative distribution of light unchanged? Although such a proposal is probably not the best practical solution, it is important to consider some of the visual consequences of a general increase in light to analyze the overall problem of low-beam headlighting.

In a nighttime field study we measured seeing distance in the presence of glare as a function of headlamp intensity, always varying the intensity of the seeing light and glare light by the same proportion. Increasing intensity by a factor of about 3.8 increased seeing distance by about 17% for both young and old drivers. This result is consistent with predictions from quantitative vision modeling using veiling luminance to represent the disabling effects of glare. We also collected subjective estimates of discomfort glare and found, as expected, that the higher intensities produced substantially more discomfort.

Our findings suggest that, if objective visual performance is the only criterion, there is no clear upper limit to how intense low-beam headlamps should be. However, there may be a level at which people simply will not tolerate the subjectively discomforting effects of glare, or at which glare indirectly affects objective performance through its effects on subjective comfort. Because subjective discomfort, rather than objective visual performance, may be the limiting consideration for setting maximum glare levels, more research should be done to understand the nature and consequences of discomfort glare, including possible effects of subjective comfort on objective visual behavior.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 1093-9741 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number GFZ @ kyba @ Serial 2127
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Author Franklin, M.; Chau, K.; Cushing, L.J.; Johnston, J.
Title Characterizing flaring from unconventional oil and gas operations in south Texas using satellite observations Type Journal Article
Year 2019 Publication Environmental Science & Technology Abbreviated Journal Environ Sci Technol
Volume 53 Issue (down) 4 Pages 2220-2228
Keywords Remote Sensing; petroleum; Texas; United States; VIIRS-DNB; Eagle Ford Shale; flaring; oil and gas
Abstract Over the past decade, increases in high-volume hydraulic fracturing for oil and gas extraction in the United States have raised concerns with residents living near wells. Flaring, or the combustion of petroleum products into the open atmosphere, is a common practice associated with oil and gas exploration and production, and has been under-examined as a potential source of exposure. We leveraged data from the Visible Infrared Imaging Spectroradiometer (VIIRS) Nightfire satellite product to characterize the extent of flaring in the Eagle Ford Shale region of south Texas, one of the most productive in the nation. Spatiotemporal hierarchical clustering identified flaring sources, and a regression-based approach combining VIIRS information with reported estimates of vented and flared gas from the Railroad Commission of Texas enabled estimation of flared gas volume at each flare. We identified 43,887 distinct oil and gas flares in the study region from 2012-2016, with a peak in activity in 2014 and an estimated 4.5 billion cubic meters of total gas volume flared over the study period. A comparison with well permit data indicated the majority of flares were associated with oil-producing (82%) and horizontally-drilled (92%) wells. Of the 49 counties in the region, 5 accounted for 71% of the total flaring. Our results suggest flaring may be a significant environmental exposure in parts of this region.
Address Department of Preventive Medicine, University of Southern California, Los Angeles California 90032, United States; meredith.franklin(at)usc.edu
Corporate Author Thesis
Publisher ACS Place of Publication Editor
Language English Summary Language English Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN 0013-936X ISBN Medium
Area Expedition Conference
Notes PMID:30657671 Approved no
Call Number GFZ @ kyba @ Serial 2175
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Author Prayag, A.S.; Najjar, R.P.; Gronfier, C.
Title Melatonin suppression is exquisitely sensitive to light and primarily driven by melanopsin in humans Type Journal Article
Year 2019 Publication Journal of Pineal Research Abbreviated Journal J Pineal Res
Volume 66 Issue (down) 4 Pages e12562
Keywords Human Health; melatonin suppression; melanopic illuminance
Abstract INTRODUCTION: Light elicits a range of non-visual responses in humans. Driven predominantly by intrinsically photosensitive retinal ganglion cells (ipRGCs), but also by rods and/or cones, these responses include melatonin suppression. A sigmoidal relationship has been established between melatonin suppression and light intensity, however photoreceptoral involvement remains unclear. METHODS AND RESULTS: In this study, we first modelled the relationships between alpha-opic illuminances and melatonin suppression using an extensive dataset by Brainard and colleagues. Our results show that 1) melatonin suppression is better predicted by melanopic illuminance compared to other alpha-opic illuminances, 2) melatonin suppression is predicted to occur at levels as low as ~1.5 melanopic lux (melanopsin-weighted irradiance 0.2 muW/cm(2)), 3) saturation occurs at 305 melanopic lux (melanopsin-weighted irradiance 36.6 muW/cm(2)). We then tested this melanopsin-weighted illuminance response model derived from Brainard and colleagues' data and show that it predicts equally well melatonin suppression data from our laboratory, although obtained using different intensities and exposure duration. DISCUSSION: Together, our findings suggest that melatonin suppression by monochromatic lights is predominantly driven by melanopsin, and that it can be initiated at extremely low melanopic lux levels in experimental conditions. This emphasizes the concern of the non-visual impacts of low light intensities in lighting design and light-emitting devices. This article is protected by copyright. All rights reserved.
Address Lyon Neuroscience Research Center, Integrative Physiology of the Brain Arousal Systems, Waking team, Inserm UMRS 1028, CNRS UMR 5292, Universite Claude Bernard Lyon 1, Universite de Lyon, F-69000, Lyon, France
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 0742-3098 ISBN Medium
Area Expedition Conference
Notes PMID:30697806 Approved no
Call Number GFZ @ kyba @ Serial 2186
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