530 research outputs found

    Geochemistry as a Clue for Paleoweathering and Provenance of Southern Apennines Shales (Italy): A Review

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    The southern Apennines (Italy) chain is a fold-and-thrust belt mainly derived from the deformation of the African–Apulian passive margin where shallow-water, basinal, and shelf-margin facies successions, including fine-grained sediments, occur. Here, we provide a review of the geochemistry of Meso–Cenozoic shales from the Lagonegro basin to elucidate provenance and paleoweathering. The different suites of these shales are dominated by 2:1 clay minerals and are Fe shales and shales. An R-mode factor analysis suggests Ti, Al, and LREE (F1) and K2O-MgO (F2) covariance, likely related to the illite → smectite → kaolinite evolution during weathering. HREE and Y are distributed by phosphate minerals, suggesting LREE/HREE fractionation. The CIA paleoweathering proxy rules out non-steady-state weathering conditions and indicates that the source area was affected by moderate to intense weathering. The paleoprecipitation values derived from the CIA-K and CALMAG indices show median values in the 1214–1610 mm/y range. The Eu/Eu*, Sm/Nd, and Ti/Al provenance ratios point toward a UCC-like source excluding any mafic supply and suggest that the Lagonegro basin was connected, through a southern area, with the African cratonic area. However, the Eu/Eu* median value of the southern Apennine shales is quite similar to the value of the Archean shales, possibly indicating a less differentiated component. This is consistent, in many samples, with the value of the (Gd/Yb)ch ratio, suggesting that the shales likely incorporated ancient sediments derived from African Archean terranes through a cannibalistic proces

    Antibiotic resistance spread potential in urban wastewater effluents disinfected by UV/H2O2 process

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    Urban wastewater treatment plants (UWTPs) are among the main hotspots of antibiotic resistance (AR) spread into the environment and the role of conventional and new disinfection processes as possible barrier to minimise the risk for AR transfer is presently under investigation. Accordingly, the aim of this work was to evaluate the effect of an advanced oxidation process (AOP) (specifically UV/H2O2) on AR transfer potential. UV/H2O2 disinfection experiments were carried out on real wastewater samples to evaluate the: i) inactivation of total coliforms, Escherichia coli and antibiotic resistant E. coli as well as ii) possible removal of target antibiotic resistance genes (ARGs) (namely, blaTEM, qnrS and tetW). In particular, DNA was extracted from both antibiotic resistant E. coli bacterial cells (intracellular DNA), grown on selective culture media, and the whole water suspension (total DNA) collected at different treatment times. Polymerase chain reaction (PCR) assay was performed to detect the absence/presence of the selected ARGs. Real Time quantitative Polymerase Chain Reaction (qPCR) was used to quantify the investigated ARGs in terms of copiesmL(-1). In spite of the bacterial inactivation and a decrease of ARGs in intracellular DNA after 60min treatment, UV/H2O2 process was not effective in ARGs removal from water suspension (total DNA). Particularly, an increase up to 3.7Ă—10(3)copiesmL(-1) (p>0.05) of blaTEM gene was observed in total DNA after 240min treatment, while no difference (p>0.05) was found for qnrS gene between the initial (5.1Ă—10(4)copiesmL(-1)) and the final sample (4.3Ă—10(4)copiesmL(-1)). On the base of the achieved results, the investigated disinfection process may not be effective in minimising AR spread potential into the environment. The death of bacterial cells, which results in DNA release in the treated water, may pose a risk for AR transfer to other bacteria present in the receiving water body

    Multi-technique instrumental approach for the characterization of metallic archeological artifacts

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    The study of the grave goods has long been the subject of study by many researchers who, through the finds, try to reconstruct the habits and customs of disappeared civilizations. In particular, the characterization of metal artifacts (weapons, jewelry, everyday objects) allows to identify the source of the raw materials used for their manufacture, forging technologies, trade routes, and cultural interactions [1,2]. The aim of this preliminary study was, by using a multi-technique instrumental approach (XRD, Raman, XPS, XRF), the chemical-mineralogical characterization of archaeological metal finds (figure 1) from the necropolis of Siris - Heraclea (Basilicata region). The analyzes highlighted, in some of these objects, the presence of a superficial state of alteration confirming what was reported by [3]. We are carrying out biological analyzes in order to verify the presence of biological agents, which, if present, could have triggered the corrosion processes. REFERENCES [1] Pernicka E., (2004) Archaeometallurgy: examples of the application of scientific methods to the provenance of archaeological metal objects. Proc. International School Physics “Enrico Fermi”, Course CLIV, (Martini M., Milazzo M. and Piacentini M., Eds.), IOS Press Amsterdam, 309- 329. [2] Tykot R.H., (2004) – Scientific method and applications to archaeological provenance studies. Proc. International School Physics “Enrico Fermi”, Course CLIV, (Martini M., Milazzo M and Piacentini M., Eds.), IOS Press Amsterdam, 407-432. [3] Afonso S. F., Noto M. M. M., Mendonça M. H., Pimenta G., Proença L., Fonseca I. T. E., “Copper corrosion in soil: influence of chloride contents, aeration and humidity”, J. Solid State Electrochem, Vol. 13, pp. 1757-1765 (2009)

    Hydrogeology and Hydrogeochemistry of the Lauria Mountains Northern Sector Groundwater Resources (Basilicata, Italy)

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    In this study, the hydrogeological characterization of the northern sector of the Lauria Mounts carbonate hydrostructure (southern Apennines, Basilicata region) has been carried out and the hydrochemical properties of different collected groundwater samples have been characterized. Several normal springs drain the hydrostructure, some of them characterized by high annual mean discharges. Groundwater samples were collected from different springs; many parameters such as pH, electrical conductivity, and total dissolved solids have been measured, and major (cations and anions) elements and stable isotopes have been analysed following standard test procedures. Other chemical characteristics were derived from the analysed quality parameters. The results elucidate that the main hydrogeochemical processes control the chemical content and assess the quality of the groundwater within the hydrostructure. The analyses highlight that the chemical compositions of groundwater are strongly influenced by the lithology, especially limestones and dolomitic limestones; they explain and confirm the hydrogeological setting of the system. The groundwater system displays light different geochemical signatures. The processes contributing to the concentrations of major ions depend primarily on carbonate dissolution. The analysis, in all studied groundwater samples, shows that the facies groundwater type is Ca–HCO3, bicarbonate is the dominant anion, and calcium is the dominant cation with appreciable magnesium concentrations. To identify the aquifer's recharge areas, the environmental stable isotopes oxygen and hydrogen, deuterium, and 18O were analysed. The unaltered δ18O and δD signatures for the groundwater of the major springs allows identifying the recharge area of these emergencies at elevations ranging from 900 m to 1000 m (a.s.l.), pointing out the presence of deeper flow regime feeding of these springs. The groundwater sample isotopic characteristics of D and 18O suggest that most of the groundwater is recharged directly by infiltration in a high-permeability medium

    A comparative evaluation of 3 different free-form deformable image registration and contour propagation methods for head and neck MRI : the case of parotid changes radiotherapy

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    Purpose: To validate and compare the deformable image registration and parotid contour propagation process for head and neck magnetic resonance imaging in patients treated with radiotherapy using 3 different approachesthe commercial MIM, the open-source Elastix software, and an optimized version of it. Materials and Methods: Twelve patients with head and neck cancer previously treated with radiotherapy were considered. Deformable image registration and parotid contour propagation were evaluated by considering the magnetic resonance images acquired before and after the end of the treatment. Deformable image registration, based on free-form deformation method, and contour propagation available on MIM were compared to Elastix. Two different contour propagation approaches were implemented for Elastix software, a conventional one (DIR_Trx) and an optimized homemade version, based on mesh deformation (DIR_Mesh). The accuracy of these 3 approaches was estimated by comparing propagated to manual contours in terms of average symmetric distance, maximum symmetric distance, Dice similarity coefficient, sensitivity, and inclusiveness. Results: A good agreement was generally found between the manual contours and the propagated ones, without differences among the 3 methods; in few critical cases with complex deformations, DIR_Mesh proved to be more accurate, having the lowest values of average symmetric distance and maximum symmetric distance and the highest value of Dice similarity coefficient, although nonsignificant. The average propagation errors with respect to the reference contours are lower than the voxel diagonal (2 mm), and Dice similarity coefficient is around 0.8 for all 3 methods. Conclusion: The 3 free-form deformation approaches were not significantly different in terms of deformable image registration accuracy and can be safely adopted for the registration and parotid contour propagation during radiotherapy on magnetic resonance imaging. More optimized approaches (as DIR_Mesh) could be preferable for critical deformations

    Serpentinite Carbonation for CO2 Sequestration in the Southern Apennines: Preliminary Study

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    Abstract During "Mineral CO2 sequestration" the CO2 is chemically stored in solid carbonates by the carbonations of minerals. The sequestration of CO2 is permanent and safe. Mineral carbonation is an exothermic reaction and occurs naturally in the subsurface as a result of fluid–rock interactions within serpentinite. In situ carbonation aims to promote these reactions by injecting CO2 into porous, subsurface geological formations. In the northern sector of the Pollino Massif (southern Italy) extensively occur serpentinites; they are the subject of a project devoted to their possible use for in situ geological sequestration of CO2
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