Development of an Italian catalogue of potential CO2storage sites: an approach from deep wells data

Stabilize and reduce the atmospheric concentration of anthropogenic greenhouse gases is one of the principal goal that have to be accomplished in short time, in order to reduce the climate changes and the global warming, following the World Energy Outlook 2007 program by IEA. The most promising remedy, proposed for large CO2 sources like thermoelectric power plants, refineries and cement industries, is to separate the flue gas capturing the CO2 and to store it into deep sub-surface geological reservoirs, such as deep saline aquifers, depleted oil and gas fields and unminable coal beds. Among these options, deep saline aquifers are considered the reservoirs with the larger storage potentiality, as a consequence of a wide availability with respect to deep coal seems, depleted oil fields and gas reservoirs. The identification of a possible storage site necessarily passes through the demonstration that CO2 can be injected in extremely safe conditions into geological deep formations, with impermeable caprock above the aquifer/s, which physic-chemical-mineralogical conditions are useful to a better mineral and solubility trapping as well as the hydrodynamic or physical/ structural ones. In order to support the identification of potential storage reservoirs in Italy, INGV jointly with CESI RICERCA S.p.A. accomplished a detailed reworking of available geological, geophysical, geochemical and seismological data, in order to support the existing European GESTCO as well as the CO2GeoCapacity projects. Aim of this work is to establish some site selection criteria to demonstrate the possibility of the geological storage of CO2 in Italy, even if it is located in an active geodynamical domain. This research started from the study of 7575 wells drilled on Italian territory during the last 50 years for gas/oil and geothermal exploration. Among this data-set as a whole, only 1700 wells (deeper than 800 m) have been selected. Only 1290 of these wells have a public-available composite log and fit with the basic prerequisites for CO2 storage potential, mostly as deep saline aquifer/s presence. Wells data have been organized into a geodatabase containing information about the nature and the thickness of geological formations, the presence of fresh, saline or brackish water, brine, gas and oil, the underground temperature, the permeability, porosity and geochemical characteristics of the caprock and the reservoirs lithologies. Available maps, seismic and geological profiles containing or closer to the analyzed wells have been catalogued too. In order to constrain the supercritical behaviour of the CO2 and to prevent the escape of gaseous CO2 to the surface, a first evaluation of the caprock presence and quality has been done on these selected wells. Using a numerical parameterization of the caprock lithologies, a “Caprock Quality Factor” (Fbp) has been defined, which clustered the wells into 5 different classes of caprock impermeability (ranging between the lowest 1 to highest 5). The analysis shows that more than 50% of the selected wells have an Fbp Factor between 4 and 5 (good and optimal quality of caprock), and are mostly located in foredeep basins of the Alps-Apenninic Chain. The geodatabase also includes: i) the seismogenetic sources (INGV DISS 3.0.4 Database of Individual Seismogenetic Sources), ii) an elaboration of seismic events catalogues (INGV CFTI, CPTI04, NT4.1), iii) the Diffuse Degassing Structures (DDS), as part of the INGV project V5 diffuse degassing in Italy geodatabase, considered as “CO2 analogue” field-tests, iv) the distribution of the thermal anomalies on the Italian Territory, linked to the presence of volcanic CO2 emissions, in order to consider the CO2 diffuse degassing risk assessment on the Italian territory Successively it has been created a geodatabase on the nature and quality of deep aquifers for the high-ranking wells sub-dataset (where the aquifers data are available), containing the following parameters: i) presence of one or more aquifers deeper than 800 meters; ii) thickness of the aquifer/s; iii) lithology of the reservoir/s; iv) available chemical analysis; v) distance from closer power plants or other anthropogenic CO2 sources.The final aim of these work is to help to find potential areas in Italy where CO2 storage feasibility studies can be done. In these cases it is necessary to implement the knowledge by: i) better evaluation of saline aquifer quality; ii) estimation of CO2 storage capacity by 3D-modeling of deep crustal structures; iii) fluid-dynamic and geochemical modelling of water-rock-CO2 interaction paths

The role of hole transport between dyes in solid-state dye-sensitized solar cells

In dye-sensitized solar cells (DSSCs) photogenerated positive charges are normally considered to be carried away from the dyes by a separate phase of hole-transporting material (HTM). We show that there can also be significant transport within the dye monolayer itself before the hole reaches the HTM. We quantify the fraction of dye regeneration in solid-state DSSCs that can be attributed to this process. By using cyclic voltammetry and transient anisotropy spectroscopy, we demonstrate that the rate of interdye hole transport is prevented both on micrometer and nanometer length scales by reducing the dye loading on the TiO₂ surface. The dye regeneration yield is quantified for films with high and low dye loadings (with and without hole percolation in the dye monolayer) infiltrated with varying levels of HTM. Interdye hole transport can account for >50% of the overall dye regeneration with low HTM pore filling. This is reduced to about 5% when the infiltration of the HTM in the pores is optimized in 2 μm thick films. Finally, we use hole transport in the dye monolayer to characterize the spatial distribution of the HTM phase in the pores of the dyed mesoporous TiO₂

Hypernuclear spectroscopy with K−^- at rest on 7^7Li, 9^9Be, 13^{13}C and 16^{16}O

The FINUDA experiment collected data to study the production of hypernuclei on different nuclear targets. The hypernucleus formation occurred through the strangeness-exchange reaction K^-_{stop} + \; ^AZ \rightarrow \; ^A_{\Lambda}Z + \pi^-. From the analysis of the momentum of the emerging $\pi^-$, binding energies and formation probabilities of $^7_{\Lambda}$Li, $^9_{\Lambda}$Be, $^{13}_{\Lambda}$C and $^{16}_{\Lambda}$O have been measured and are here presented. The behavior of the formation probability as a function of the atomic mass number A is also discussed.Comment: Accepted for publication in PL

The A(Kstop−,π±Σ∓)A′A(K^-_{stop},\pi^\pm\Sigma^\mp)A' reaction on p-shell nuclei

This letter is concerned with the study of the $K^-_{stop}A\rightarrow \pi^\pm\Sigma^\mp A'$ reaction in p-shell nuclei, i.e., $^{6,7}Li$, $^9Be$, $^{13}C$ and $^{16}O$. The $\pi^\pm\Sigma^\mp / K^-_{stop}$ emission rates are reported as a function of $A$. These rates are discussed in comparison with previous findings. The ratio $\pi^-\Sigma^+/\pi^+\Sigma^-$ in p-shell nuclei is found to depart largely from that on hydrogen, which provides support for large in-medium effects possibly generated by the sub-threshold $\Lambda(1405)$. The continuum momentum spectra of prompt pions and free sigmas are also discussed as well as the $\pi^\pm\Sigma^\mp$ missing mass behavior and the link with the reaction mechanism. The apparatus used for the investigation is the FINUDA spectrometer operating at the DA$\Phi$NE $\phi$-factory (LNF-INFN, Italy).Comment: 14 pages, 5 figures, accepted for publication in Phys. Lett.

An improved determination of the two--nucleon induced non mesonic weak decay of Λ\Lambda-hypernuclei

The decay of $\Lambda$-hypernuclei without pion emission, known as Non Mesonic Weak Decay (NMWD), gives an effective tool to investigate $\Delta$S=1 four-baryon interactions. It was theoretically suggested that the two-nucleon induced mechanism could play a substantial role in reproducing the observed NMWD decay rates and nucleon spectra, but at present no direct evidence of such a mechanism has been obtained. The FINUDA experiment, exploiting the possibility to detect both charged and neutral particles coming from the hypernucleus decay, has allowed us to deduce the relative weight of the two nucleon induced decay rate to the total NMWD rate. The value of $\Gamma_{2N}$/$\Gamma_{NMWD}$=0.24$\pm$${0.03_{stat}}^{+0.03_{sys}}_{{-{0.02_{sys}}}}$ has been deduced, with an error reduced by a factor more than two compared with the previous assessment.Comment: 10 pages, 3 figure

Neutron-proton coincidences from Non-Mesonic Weak Decay of p-shell Lambda-hypernuclei and determination of the two-nucleon induced process

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Evidence for 6{\Lambda}H

Evidence for the neutron-rich hypernucleus 6{\Lambda}H is presented from the FINUDA experiment at DA{\Phi}NE, Frascati, studying ({\pi}+, {\pi}-) pairs in coincidence from the K- +6Li \rightarrow 6 H+{\pi}+ production reaction followed by 6{\Lambda}H \rightarrow 6He + {\pi}- weak decay. The production rate of 6{\Lambda}H undergoing this two-body {\pi}- decay is determined to be (2.9\pm2.0)\cdot10-6/K-. Its binding energy, evaluated jointly from production and decay, is B{\Lambda}(6{\Lambda}H) = (4.0\pm1.1) MeV with respect to 5H+{\Lambda}. A systematic difference of (0.98 \pm 0.74) MeV between B{\Lambda} values derived separately from decay and from production is tentatively assigned to the 6{\Lambda}H 0+g.s. \rightarrow 1+ excitation.Comment: 5 pages, 3 figure

D-dimer testing, with gender-specific cutoff levels, is of value to assess the individual risk of venous thromboembolic recurrence in non-elderly patients of both genders: a post hoc analysis of the DULCIS study

Male patients, especially the young, are at a higher risk of recurrent venous thromboembolism (RVTE) than females. Recent scientific reports show the use of D-dimer does not help predict RVTE risk in males. In the present report, we reviewed the data obtained in the DULCIS study (main report published in Blood 2014), focusing on D-dimer results recorded in non-elderly patients of both genders included in the study, and their relationship with RVTE events occurring during follow-up. Using specifically designed cutoff values for positive/negative interpretation, serial D-dimer measurements (performed during warfarin treatment and up to 3 months after discontinuation of anticoagulation) in 475 patients (males 57.3%) aged 64 65 years were obtained. D-dimer resulted positive in 46.3% and 30.5% of males and females, respectively (p = 0.001). Following management procedure, anticoagulation was stopped in 53.7% of males and 69.5% of females, who had persistently negative D-dimer results. The rate of subsequent recurrent events was 1.7% (95% CI 0.5\u20134.5%) and 0.4% (95% CI 0\u20132.5%) patient-years in males and females, respectively, with upper limits of confidence intervals always below the level of risk considered acceptable by international scientific societies for stopping anticoagulation (< 5%). In conclusion, using sensitive quantitative assays with specifically designed cutoff values and serial measurements during and after discontinuation of anticoagulation, D-dimer testing is useful to predict the risk of RVTE and is of help in deciding the duration of anticoagulation in both male and female adult patients aged up to 65 years