2,730 research outputs found
One year of measurements with a POM02 sun-sky radiometer at an Alpine Euroskyrad station
No full textLaboratory implementation of edge illumination X-ray phase-contrast imaging with energy-resolved detectors
No full textEdge illumination (EI) X-ray phase-contrast imaging (XPCI) has potential for applications in different fields of research, including materials science, non-destructive industrial testing, small-animal imaging, and medical imaging. One of its main advantages is the compatibility with laboratory equipment, in particular with conventional non-microfocal sources, which makes its exploitation in normal research laboratories possible. In this work, we demonstrate that the signal in laboratory implementations of EI can be correctly described with the use of the simplified geometrical optics. Besides enabling the derivation of simple expressions for the sensitivity and spatial resolution of a given EI setup, this model also highlights the EI’s achromaticity. With the aim of improving image quality, as well as to take advantage of the fact that all energies in the spectrum contribute to the image contrast, we carried out EI acquisitions using a photon-counting energy-resolved detector. The obtained results demonstrate that this approach has great potential for future laboratory implementations of EI. © (2015) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only
Analysis of two-decade meteorological and air quality trends in Rome (Italy)
No full textThis study presents a trend analysis of a two-decade (2000–2020) series of surface meteorological and air quality data measured in Rome (Italy). Data series are collected at three sites in Rome downtown and its coastal surroundings. This paper fills the gap due to missing or incomplete recent information about the meteorological and atmospheric composition tendencies in the Rome area. Datasets are subjected to in-depth quality control and to statistical analysis to verify the data homogeneity, whilst trend analysis is performed using the Seasonal Kendall test. The results show a statistically significant positive trend for average air temperature (0.07 °C year−1 in urban and coastal sites), whilst maximum and minimum temperatures increase more in urban (0.10 °C year−1) than in coastal (0.01 °C year−1) environment. The water vapour mixing ratio trend is higher in the city (0.10 g kg−1 year−1) than along the coast (0.03 g kg−1 year−1). The heat index tendency is more pronounced in the Rome centre (0.11 °C year−1) than in the coast (0.06 °C year−1). The monthly cumulative precipitations do not show statistically significant trends. On the other hand, air quality generally improved: surface pollutant concentrations show a significant decrease thanks to the reduction of local emissions (C6H6, − 0.12 μg m−3 year−1; SO2, − 0.09 μg m−3 year−1; CO, − 0.02 mg m−3 year−1; NOx, − 1.28 μg m−3 year−1; NO, − 0.38 μg m−3 year−1; NO2, − 0.60 μg m−3 year−1, PM10, − 0.35 μg m−3 year−1). Only O3 shows a statistically significant positive trend (0.15 μg m−3 year−1), in agreement with wider scale studies. The outcomes suggest that whilst local and national policies contribute to the improvement of air quality, the rising of temperature—as likely consequence of climate change—may be an emerging cause of concern for human thermal discomfort and potential effect on the conservation of tangible immovable heritage
Parton densities from deep inelastic scattering to hadronic processes at super collider energies
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Due applicazioni della fotometria solare allo studio della qualità dell'aria: determinazione del diossido d'azoto e delle proprietà ottiche degli aerosol
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Lumen: a higly versatile spectrophotometer for measuring the transmittance throughout very long samples as well microstructures
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