1,721,157 research outputs found
Ricostruzione di eventi deformativi di versante tardo-quaternari ed olocenici attraverso studi geomorfologici e datazioni radiometriche Th/U: l'esempio dell'area di Vico Equense (Campania).
No full textGeocronologia radiometrica dei depositi travertinosi posti al tetto dell’unità di Roccarespampani col metodo del Th-230/U-234. Procedura L/L.
No full textRicostruzione di eventi deformativi di versante tardo-quaternari ed olocenici attraverso studi geomorfologici e datazioni radiometriche Th/U: l'esempio dell'area di Vico Equense (Campania).
No full text
U/TH DATING AND GEOCHEMISTRY OF CARBONATE CONCRECTIONS ASSOCIATED WITH UPPER PLEISTOCENE FOSSIL SHORELINES OF THE SORRENTO PENINSULA (CONCA DEI MARINI, SOUTHERN ITALY).
No full textCorrecting for CO2 interference in soil radon flux measurements
No full textIn the present paper the interference of high CO2 concentration in soil radon flux measurement using a solid state silicon detector is
discussed. A possible correction, making use of a chemical trap consisting of soda lime pellets, is successfully experimented at Cava dei Selci
site (Roma, Italy). The interference is likely due to neutralization processes of 218Po ions in the CO2 dominant atmosphere occurring in the
chamber of radon monitor and resulting in a reduced efficiency in electrostatic collection on the surface of the solid state detecto
226Ra chronology of Holocene travertine from Esanatoglia (Central Italy)
No full textHere we investigate the feasibility of using alpha-spectrometric 226Ra methodology to date low U freshwater carbonate deposits
(<0.1 μg g-1) by analysing Holocene freshwater travertine deposits from Esanatoglia, Umbro-Marchean Apennines, Central Italy.
Previously, such methods have been tested on hydrothermal deposits, which are characterised by high Ra and U. We calculate a 226Ra
age estimate of 2.9 ± 0.4 ka (1σ) for Holocene travertine that is in reasonable agreement with archaeological evidence by assuming that
the 226Ra initial activity of the Holocene travertine is comparable with that of present-day carbonate deposits in the same area. We also
investigate the use of Ba to normalise 226Ra activities. Comparison of age estimates based on Ra methods with ages derived from alphaspectrometric
230Th/234U isochron techniques for the same co-eval sub-samples indicates that, where only alpha-spectrometric methods
are available, the former are likely to be much more useful for Holocene travertine material, especially if there is a significant detrital
component
Variazioni delle concentrazioni di radon indoor in un edificio a tre piani costruito sui depositi alluvionali del Tevere (Roma). Risultati preliminari
No full textVariazione del rilascio di CO2 durante gli ultimi 200 anni registrate dagli speloetemi della grotta centroni (Roma, Italia)
No full textUsing 222-Radon as tracer for areal and vertical distribution of hydrocarbon contaminations
No full textNon-aqueous Phase Liquids (NAPLs), including crude oil and its refined products, produce a long lasting
impact on the enviroment due to unwilling releases. Storage sites of fuel and pump stations are often involved
in unwilling NAPL spills in the subsoil and/or groundwater. The non-polar nature of these contaminants
confers them a slight solubility in water, causing a reduced efficency of the most common remediation
techniques. These limitations result in long-term remediation activities with high related costs. Unconventional
characterization methods like the Radon (222Rn)-deficit technique are meant to supplement and optimize the
conventional approach by providing dense spatial information in quasi-real time, and at a reasonable cost
(De Miguel et al., 2020). Schubert (2015) presented a comprehensive review of the use of 222Rn as a natural
tracer to assess subsurface NAPL contamination. In the present work Radon deficit technique was applied to
determine the vertical distribution of Rn in groundwater inside a gasoline contaminated area. Twelve passive
accumulators PDMS-AC (polydimethylsiloxane mixed with activated carbon) were inserted at different depth
inside fenestrated piezometers and left for two weeks to maximize the Rn accumulation. Then they were
measured by high resolution gamma spectometry. PDMS-AC are characterized by a high permeability to Rn
and impermeability to water (Voltaggio & Spadoni, 2013). The obtained results suggest the possible application
of Radon deficit to find not only the areal but also the vertical distribution of a NAPL contamination in the
saturated level. This datum could offer interesting applications to estimate initial and residual volumes of the
contaminant during remediation procedures
- …
