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 have been doubled in the last 18 years in most of the provinces.
We present a study of the night sky brightness around the extended metropolitan area of Madrid using Sky Quality Meter (SQM) photometers. The map is the first to cover the spatial distribution of the sky brightness in the center of the Iberian peninsula. These surveys are neccessary to test the light pollution models that predict night sky brightness as a function of the location and brightness of the sources of light pollution and the scattering of light in the atmosphere. We describe the data-retrieval methodology, which includes an automated procedure to measure from a moving vehicle in order to speed up the data collection, providing a denser and wider survey than previous works with similar time frames. We compare the night sky brightness map to the nocturnal radiance measured from space by the DMSP satellite. We find that i) a single source model is not enough to explain the radial evolution of the night sky brightness, despite the predominance of Madrid in size and population, and ii) that the orography of the region should be taken into account when deriving geo-specific models from general first-principles models. We show the tight relationship between these two luminance measures. This finding sets up an alternative roadmap to extended studies over the globe that will not require the local deployment of photometers or trained personnel.
This paper reports on the simultaneous detection of Mg, Mn, Fe and Pb in A1 samples using laser-induced breakdown spectroscopy and optical multichannel analysis of the photoablated microplasma. Using calibrated samples, well characterized linear working curves were determined for these minor components over the 0.01-1% concentration range. In addition optimum experimental conditions were found that allow the analysis to be carded out in a fast and non-invasive manner. The potential application of the method to on-line industrial analysis is also suggested.
A C02 laser-induced SF6 4-Ba beam-surface ionization process has been studied in which vibrational excitation of SF6 molecules was carried out at the polished surface of polycrystalline Ba electrically heated to 675 K.Both electron emission and negative molecular ion signal were detected. The dependence of the molecular ion signal on laser fluence and frequency (on SF6 molecular absorption) as well as on the SF6 gas pressure in the nozzle was studied. The results suggest a clear vibrational selectivity, i.e., vibrational enhancement, of the SF6 + Ba beam-surface ionization process. Several possible mechanisms for the negative molecular ion formation in the IR laser-induced beam-surface ionization process are discussed.
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