Africa is one of the most vulnerable continents to climate change. In the upcoming decades the occurrence of longer, hotter and more frequent heat waves could have a strong impact on human mortality ...and crop production. Here, by applying the heat wave magnitude index daily to temperature reanalysis data, we quantify the magnitude and the spatial extent of the most extreme heat waves experienced in Africa between 1979 and October 2015 across different seasons. Results show that in the recent years Africa experienced hotter, longer and more extent heat waves than in the last two decades of the 20th century. In the future, 50% of regional climateprojections suggest that heat waves that are unusual under present climate conditions will occur on a regular basis by 2040 under the most severe IPCC AR5 scenario (i.e. RCP8.5).
Waters of Mt. Etna are the main source of drinking water for the local population and are also distributed in municipal supply systems to neighbouring areas. Radioactivity in underground waters and ...surrounding rocks from the eastern flank of Mt.Etnawas investigated on the basis of 9 water and 8 rocks samples from 12 localities altogether. Three samples were from water drainage galleries and six from water wells. All water intakes are used for consumption. Activity concentration of uranium isotopes 234,238U, radium isotopes 226,228Ra and radon 222Rn were determined with the use different nuclear spectrometry techniques. The determination of uranium isotopes was carried out with the use of alpha spectrometry. The measurements of radium and radon activity concentration in water were performed with the use of a liquid scintillation technique. Additionally, rocks surrounding the intakes were examined with gamma spectrometry. All water samples showed uranium concentration above Minimum Detectable Activity (MDA), with the highest total uranium (234U + 238U) activity concentration equal to 149.2±6 mBq/L. Conversely, all samples showed radium isotopes activity concentrations below MDA. Radon activity concentration was within the range from 2.91±0.36 to 21.21±1.10 Bq/L, hence these waters can be classified as low – radon waters. Gamma natural background of the rocks surrounding the water sampling sites was found on the same levels as other volcanic rocks of Italy.
We investigate the ability of GPS to detect volcanic plumes at Mt. Etna, Italy. We use a robust statistical approach to highlight whether the presence of a volcanic plume in the atmosphere may really ...affect the GPS undifferenced post-fit phase residuals. The proposed method has been tested for the September 4–5, 2007 activity of Mt. Etna. This eruption produced powerful lava fountains forming a weak, a few kilometers high plume for several hours, representing typical activity at Etna over the last 5 years. We analyzed data from nineteen Etna permanent GPS stations located on the volcano flanks at different heights and applied a statistical test based on four main steps: (a) realization of a simplified model representing the volcanic plume in atmosphere; (b) evaluation of the GPS satellite and station couples intersecting the plume; (c) calculation of the volcanic plume region crossed by the GPS signal; (d) application of a robust statistical test in order to see whether the volcanic plume affected the GPS signals. Results show that during the September 4–5, 2007 explosive activity, the GPS residuals definitely include the contribution of the volcanic plume. Our analysis shows that values of the GPS residuals are ten times smaller than those found for the Miyakejima eruption (Japan), highlighting a likely relationship between residuals and eruption intensity. In the future, data derived from the GPS stations located on Etna’s flanks could be used to improve the alerting system of volcanic ash, already operating at the Istituto Nazionale di Geofisica e Vulcanologia, Osservatorio Etneo.
Characteristics of radon transport in porous media were studied through both in situ and lab-scale measurements. In situ measurements of radon activity concentration, together with soil thoron and ...carbon dioxide efflux, were carried out on Mt. Etna volcano. More detailed information on radon transport mechanisms has been obtained from laboratory measurements. In particular, we report the first results of a systematic study carried out at the University of Catania (Italy) by means of a facility consisting of a large cylindrical stainless steel vessel, homogeneously filled with different materials. Radon concentration vertical profiles were extracted in low-moisture samples for different advective fluxes, temperatures and porosities.
Indoor radon behavior in two sites of SE Sicily was studied as a function of the soil radon concentration. The chosen locations were Ragusa and Modica towns, placed in the Hyblean Plateau (northern ...margin of the African Plate). Soil samples were analysed by gamma spectrometry to determine the amount of radionuclides. Indoor air and soil gas radon measurements were simultaneously performed in both sites using active detectors. Radon in soil was measured one meter deep. A positive correlation was obtained between indoor radon concentration and the soil gas concentration.
Purpose
Localization and quali-quantitative characterization of radionuclide-contaminated soils are essential for healthcare and remediation activities. However, characterization activities are at ...the moment mainly based on very complex activities, generally dangerous for workers’ health. Unmanned aerial vehicles (UAVs) can be considered for this purpose, but the absence of data does not permit their use for a quantitative analysis. The main goal of this work is to obtain scientific information for successfully using UAVs in quali-quantitative characterization activities.
Materials and methods
The influence of the main flight UAV condition parameters on the detection efficiency and minimum detectable activity (MDA) concentration was assessed at lab-scale, considering
241
Am and
152
Eu as simulated soil contaminants. Obtained data were compared with reference to clearance levels. Specifically, the altitude (
h
) and inclination (
θ
) with respect to the soil surface of a small size γ-ray semiconductor CdTe detector and detection time were investigated as flight parameters.
h
and
θ
were adopted in the range 0–70 cm and 0°–60°, respectively.
Results and discussion
Main results reveal that in the case of
241
Am contamination, a duration time of about 13 and 20 min is required for an altitude of 60 and 70 cm, respectively, if an inclination of zero is considered, whereas inclinations higher than 15° lead to much longer times, up to 40 min. In the presence of
152
Eu, results reveal a more marked influence of the variables
h
and
θ
on the minimum detection time, with values higher for
241
Am. In terms of MDA, in the case of
241
Am, all the concentration values, with the exception of the highest
θ
investigated (60°), are below the Italian regulatory limit for altitudes lower than 35 cm and a detection time of 30 min. Higher
h
up to 50 cm can be considered, reducing the inclination up to 0°, whereas even higher altitudes make the detection of
241
Am not possible. On the other hand, for
152
Eu, the observed MDA values always make the contaminant detection possible.
Conclusions
All achievements and the calculated fitting parameters are useful preliminary data in the quantitative characterization of soil surface contamination, representing a valuable tool in knowing the soil surface γ-ray activity of
241
Am and
152
Eu for each given detected value. In general, obtained results will allow a better understanding of the technique limits and operating methods required for characterization activities by UAVs with vertical take-off and landing system.
We report preliminary observations on possible correlations between anomalies of subsoil radon concentration and geodynamical events on Mt. Etna. In recent years several studies have been carried out ...on radon as a precursor of geophysical events, most of them performed either on tectonic or volcanic areas. The peculiarity of our investigation lies on the choice of the etnean region, in which tectonic and volcanic features are both present. In order to characterize Mt. Etna features by investigating radon gas in soil, two stations were located along the NE-SW direction on Mt. Etna. Each of the two stations is fitted with a radon detector, a 3D seismic station and a meteorological station. Differences in the radon concentration trend in the data from north and south flanks could be linked to different faulting mechanisms and then to different mechanisms of radon uprising. The increase in soil radon concentration could be related to both seismic and volcanic events.
This is a collection of invited talks and oral contributions presented by the leading scientists in their fields, summarizing the most recent progress of, and new prospects for, nuclear physics ...research.It covers a broad range of the recent developments in nuclear physics: reactions between massive nuclei leading to superheavy element formation; radioactive beams and neutron-rich systems; exotic nuclei and nuclear astrophysics; new states of nuclear matter.
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