This study underlines that an accurate temporal monitoring

This study underlines that an accurate temporal monitoring of this kind of phenomena may help to increase our knowledge on the origin of gases, the existence of eventual multiple gas reservoirs and on the correct actions to be undertaken in order to restore the natural environmental equilibrium in presence of pressurized gas pockets. In turn, this is useful to better address the environmental gas hazard assessment in areas, such that of Fiumicino, particularly prone to this risk.
1. Introduction
The exact structure of tungsten borides is still a AZD7762 of vigorous debate in the literature. Liang et al. [20] showed that W2B5 cannot exist at zero and high pressures, but the similar structure WB2 is far more favorable in Gibbs energy. Those observations supports the recent theoretical and experimental conclusions hemoglobin W2B5 in fact is defective WB2[21] and [22]. Moreover, the previously experimentally attributed WB4 is in fact is the defect-containing WB3[21] and [23]. Firstly, the lattice constants of WB3 (a=5.200 Å, c=6.313 Å) [21] are closer to experimental values (a=5.159 Å, c=6.332 Å) [16] than lattice parameters of WB4 (a=5.360 Å, c=6.453 Å). Secondly, Young?s moduli are strikingly different for both phases. For WB3, its theoretical value is 609 GPa [23], which is consistent with the measured results of 553–599 GPa [7], whereas that of WB4 is only 299 GPa.