15 research outputs found
Geological and Hydrogeological Characterization of Springs in a DSGSD Context (Rodoretto Valley – NW Italian Alps)
As continuous groundwater monitoring in the upper sector of Rodoretto Valley (Germanasca Valley, Italian Western Alps) is hampered by logistical problem of data collection during winter and spring months, the only tools currently available to derive hydrogeological information are non-continuous and non-long-term dataset of spring discharge (Q), temperature (T) and electrical conductivity (EC).
In order to quantity aquifer groundwater reserve, available Q dataset of a small mountain spring (Spring 1 CB) was investigated by applying the analytical solutions developed by Boussinesq (J Math Pure Appl 10:5–78, 1904) and Maillet (Essais dı’hydraulique souterraine et fluviale, vol 1. Herman et Cie, Paris, 1905); T and EC datasets were also used to provide qualitative information about the nature of the aquifer that supplies the spring.
The outcomes of the elaborations highlighted the limits of applicability of these methods in the presence of a non-continuous Q dataset: both Boussinesq (J Math Pure Appl 10:5–78, 1904) and Maillet (Essais dı’hydraulique souterraine et fluviale, vol 1. Herman et Cie, Paris, 1905) estimated that discharge values as a function of recession time were found to be consistently lower than the available discharge ones and the estimated groundwater volumes stored over time above the spring level turned out to be underestimated.
Continuous (hourly value) and long-term Q, EC and T values are, therefore, needful to correctly quantify and to make a proper management of groundwater resources in mountain areas
Co-seismic and post-seismic changes in groundwater discharge: First results from the epicentral region of the Central Italy earthquake 2016
Short and mid-term effects of earthquakes on groundwater flow were documented in several studies. The hydrogeological response of groundwater flow systems to earthquakes is very complex and due to significant changes in permeability. Such hydrologic changes may occur even at great distances from the epicentre and their magnitude may be related to the proximity to the earthquake focus. Central Italy has been hit by several large earthquakes since August 2016. With reference to the carbonate aquifers located in the epicentral region, the following short term effects were observed: a significant increase of the spring discharges and the disappearance of several perched springs. The deep-seated fault movements and fluid redistribution may cause water-level fluctuations as well as changes in groundwater discharge and composition. This study describes a preliminary characterization of such processes. © Società Geologica Italiana, Roma 2019
The effects of in-stream gravel mining on river incision: an example from Central Adriatic Italy
Density Functional Theory modelling of protection agents for carbonate stones: case study of oxalate and oxamate inorganic salts
Sulphur and nitrogen oxide pollutants cause acid rain that can eventually lead to the dissolution of calcite in
marble and limestones. Calcium oxalate is an inorganic protective agent, which is obtained by treatment
with ammonium oxalate. The functionalization of oxalic acid to give monoesters and monoamides
(oxamates) allows tailoring the solubility of the relevant ammonium and calcium salts. In this context,
theoretical calculations carried out at the Density Functional Theory (DFT) level were exploited to investigate
the capability of oxalate, methyloxalate, phenyloxalate, oxamate, methyloxamate, and phenyloxamate to
interact with the calcium carbonate lattice. An in-depth validation based on the structural data showed
that DFT calculations with the PBE0 functional along with a single or triple-zeta def2 basis set allow
understanding the different reactivity of the oxalate and oxamate derivatives and their efficiency in
interacting with stones containing calcium carbonate, such as Carrara marble and biomicritic limestones
A combined approach for a modern hydrogeological mapping: the case study of Tennacola stream catchment (central Apennine, Italy)
Occupational exposure to VOCs from the evaporation of gasoline. An assessment of the problem for service station attendants in Italy.
Concentrazioni di benzene nei vapori di benzina: studio rappresentativo dei livelli di esposizione negli addetti alla erogazione di carburanti.
Ammonium monoethyloxalate (AmEtOx): a new agent for the conservation of carbonate stone substrates
The ammonium salt of monoethyloxalate (AmEtOx) was investigated as a novel precursor for the conservation of carbonate stone substrates, such as biomicritic limestone and marble. Full characterization of treated and untreated authentic stone samples was carried out by means of SEM, X-ray powder diffraction, synchrotron tts-mXRD measurements, mercury intrusion porosimetry, determination of water transport properties, and pull-off tests. The improved solubility (1.49 M, 20.1% w/w) of AmEtOx as compared to that of ammonium oxalate (AmOx; 0.4 M, 5% w/w) results in the formation of microcrystalline phases 30–50 and 200–500 mm thick of calcium oxalate mono-(whewellite) or dihydrate (weddellite), on marble and biomicrite samples, respectively, after treatment with AmEtOx 5% and 12% w/w aqueous solutions. As a result, a reduction in the porosity of the stone samples and an enhancement of their cohesion are observed. DFT calculations, carried out to investigate the hydrolysis reaction leading from AmEtOx to AmOx, showed that the localization of the Lowest Unoccupied Molecular Orbital (LUMO) and the natural charge distribution account nicely for the tendency to hydrolyse observed experimentally, eventually leading to the formation of whewellite and weddellite on the stone surface