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Author Kocifaj, M. url  doi
openurl 
  Title Towards a Comprehensive City Emission Function (CCEF) Type Journal Article
  Year 2018 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal JQSRT  
  Volume (down) 205 Issue Pages 253-266  
  Keywords Lighting; Skyglow  
  Abstract The comprehensive city emission function (CCEF) is developed for a heterogeneous light-emitting or blocking urban environments, embracing any combination of input parameters that characterize linear dimensions in the system (size and distances between buildings or luminaires), properties of light-emitting elements (such as luminous building façades and street lighting), ground reflectance and total uplight-fraction, all of these defined for an arbitrarily sized 2D area. The analytical formula obtained is not restricted to a single model class as it can capture any specific light-emission feature for wide range of cities. The CCEF method is numerically fast in contrast to what can be expected of other probabilistic approaches that rely on repeated random sampling. Hence the present solution has great potential in light-pollution modeling and can be included in larger numerical models. Our theoretical findings promise great progress in light-pollution modeling as this is the first time an analytical solution to city emission function (CEF) has been developed that depends on statistical mean size and height of city buildings, inter-building separation, prevailing heights of light fixtures, lighting density, and other factors such as e.g. luminaire light output and light distribution, including the amount of uplight, and representative city size. The model is validated for sensitivity and specificity pertinent to combinations of input parameters in order to test its behavior under various conditions, including those that can occur in complex urban environments. It is demonstrated that the solution model succeeds in reproducing a light emission peak at some elevated zenith angles and is consistent with reduced rather than enhanced emission in directions nearly parallel to the ground.  
  Address  
  Corporate Author Thesis  
  Publisher ScienceDirect Place of Publication Editor  
  Language English Summary Language English 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 LoNNe @ kyba @ Serial 1757  
Permanent link to this record
 

 
Author Bará, S.; Escofet, J. url  doi
openurl 
  Title On lamps, walls, and eyes: The spectral radiance field and the evaluation of light pollution indoors Type Journal Article
  Year 2018 Publication Journal of Quantitative Spectroscopy and Radiative Transfer Abbreviated Journal J of Quant Spect and Rad Trans  
  Volume (down) 205 Issue Pages 267-277  
  Keywords Instrumentation; Light pollution; Artificial light at night; Light field; Radiance field; Radiometry; Photometry  
  Abstract Light plays a key role in the regulation of different physiological processes, through several visual and non-visual retinal phototransduction channels whose basic features are being unveiled by recent research. The growing body of evidence on the significance of these effects has sparked a renewed interest in the determination of the light field at the entrance pupil of the eye in indoor spaces. Since photic interactions are strongly wavelength-dependent, a significant effort is being devoted to assess the relative merits of the spectra of the different types of light sources available for use at home and in the workplace. The spectral content of the light reaching the observer eyes in indoor spaces, however, does not depend exclusively on the sources: it is partially modulated by the spectral reflectance of the walls and surrounding surfaces, through the multiple reflections of the light beams along all possible paths from the source to the observer. This modulation can modify significantly the non-visual photic inputs that would be produced by the lamps alone, and opens the way for controlling—to a certain extent—the subject's exposure to different regions of the optical spectrum. In this work we evaluate the expected magnitude of this effect and we show that, for factorizable sources, the spectral modulation can be conveniently described in terms of a set of effective filter-like functions that provide useful insights for lighting design and light pollution assessment. The radiance field also provides a suitable bridge between indoor and outdoor light pollution studies.  
  Address Área de Óptica, Departamento de Física Aplicada, Universidade de Santiago de Compostela, Santiago de Compostela, Galicia, Spain; salva.bara(at)usc.es  
  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 0022-4073 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number IDA @ john @ Serial 2163  
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Author Studer, P.; Brucker, J.M.; Haag, C.; Van Doren, J.; Moll, G.H.; Heinrich, H.; Kratz, O. url  doi
openurl 
  Title Effects of blue- and red-enriched light on attention and sleep in typically developing adolescents Type Journal Article
  Year 2018 Publication Physiology & Behavior Abbreviated Journal Physiol Behav  
  Volume (down) 199 Issue Pages 11-19  
  Keywords Human Health  
  Abstract Differential effects of blue- and red-enriched light on attention and sleep have been primarily described in adults. In our cross-over study in typically developing adolescents (11-17years old), we found attention enhancing effects of blue- compared to red-enriched light in the morning (high intensity of ca. 1000lx, short duration: <1h) in two of three attention tasks: e.g. better performance in math tests and reduced reaction time variability in a computerized attention test. In our pilot study, actigraphy measures of sleep indicated slight benefits for red- compared to blue-enriched light in the evening: tendencies toward a lower number of phases with movement activity after sleep onset in the complete sample and shorter sleep onset latency in a subgroup with later evening exposure times. These findings point to the relevance of light concepts regarding attention and sleep in typically developing adolescents. Such concepts should be developed and tested further in attention demanding contexts (at school) and for therapeutic purposes in adolescents with impaired attention or impaired circadian rhythms.  
  Address Department of Child and Adolescent Mental Health, University Hospital Erlangen, Friedrich-Alexander-Universitat Erlangen-Nurnberg (FAU), Erlangen, Germany. Electronic address: oliver.kratz@uk-erlangen.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 0031-9384 ISBN Medium  
  Area Expedition Conference  
  Notes PMID:30381244 Approved no  
  Call Number GFZ @ kyba @ Serial 2142  
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Author Doumbia, E.H.T.; Liousse, C.; Keita, S.; Granier, L.; Granier, C.; Elvidge, C.D.; Elguindi, N.; Law, K. url  doi
openurl 
  Title Flaring emissions in Africa: Distribution, evolution and comparison with current inventories Type Journal Article
  Year 2019 Publication Atmospheric Environment Abbreviated Journal Atmospheric Environment  
  Volume (down) 199 Issue Pages 423-434  
  Keywords Remote Sensing  
  Abstract Flaring emissions are a major concern due to large uncertainties in the amount of chemical compounds released into the atmosphere and their evolution with time. A methodology based on DMSP (Defense Meteorological Satellite Program) nighttime light data combined with regional gas flaring volumes from National Oceanic and Atmospheric Administration's National Centers for Environmental Information (NOAA-NCEI) has been developed to estimate flaring emissions. This method is validated in Nigeria where individual field company data are available. The spatial distribution of CO2, CH4, NMVOCs, CO, OC, BC, SO2 and NOx is derived for the African continent for the period 1995–2010.

A range of the emissions due to flaring is estimated based on the range of emission factors (EFs) for each chemical species. An average decrease in CO2 emissions of about 30% is found over Africa from 1995 to 2010, with Nigeria being the largest contributor to this reduction (up to 50%). Changes in the spatial distribution with time indicate local increases, particularly at offshore platforms, which are attributed to a lack of regulations as well as aging infrastructures in oil and gas fields.

Comparisons with current inventories reveal differences in the location and magnitude of point source emissions. For chemical compounds such as NMVOCs and CH4, the ECLIPSE and EDGAR country-level values are considerably higher than the highest flaring emission estimated in this study for 2005. For species such as CO, OC, BC, SO2 and NOx, the emissions provided by the ECLIPSE and EDGAR inventories are generally within the same order of magnitude as the average values found in this study, with the exception of OC, BC and SO2 in which EDGAR provides much lower emissions. These discrepancies are likely due to either differences in the methodologies used to estimate the emissions, in the values of the emission factors considered, or in the definition of flaring sector. Our current estimations suggest that BC, CH4 and CO2 flaring emissions in Africa account for 1–15% (on average 7%), 0.5–8% (on average 2%) and 8–13% (on average 11%) of African total anthropogenic emissions, respectively. The contribution of flaring to African anthropogenic emissions varies widely among countries. For example, in Nigeria the average emissions due to flaring are estimated to be as high as 18% for BC, 10% for CH4 and 50% for CO2, which is significantly greater than the continental average and highlights the importance of emissions in flaring 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 1352-2310 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2176  
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Author Marwan, W.; Hegemann, P.; Oesterhelt, D. url  doi
openurl 
  Title Single photon detection by an archaebacterium Type Journal Article
  Year 1988 Publication Journal of Molecular Biology Abbreviated Journal Journal of Molecular Biology  
  Volume (down) 199 Issue 4 Pages 663-664  
  Keywords Bacteria  
  Abstract Halobacteria are attracted by green and repelled by near ultraviolet or blue light. The photophobic response to blue light is mediated by the retinal protein P480. The analysis of stimulus response curves with Poisson statistical methods reveals that the photophobic response can be elicited at minimum by a single photon.  
  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 0022-2836 ISBN Medium  
  Area Expedition Conference  
  Notes Approved no  
  Call Number GFZ @ kyba @ Serial 2754  
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