713 research outputs found

    A regional-scale conceptual and numerical groundwater flow model in fluvio-glacial sediments for the Milan Metropolitan area (Northern Italy)

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    Study region: The Milan metropolitan area lies on one of the most important aquifer in Italy, heavily exploited for public and industrial water supply. The area, covering 3135 km2 in the Po Plain (Northern Italy) with a continental climate, is bounded by the Po, the Adda and the Ticino rivers and by the prealpine foothills. Regional hydrology is characterised by a network of natural and man-made elements, and lowland springs. The sedimentary sequence, from bottom to top, is formed by meandering river plain deposits, the distal fringe of the glacial outwash plains and proximal braid-plain deposits. Study focus: This study proposes a general approach for aquifer geometry reconstruction and hydrodynamic parametrization of hydrofacies in fluvio-glacial deposits, and their implementation into a 3D regional groundwater flow model. This approach is based on sedimentologically-defined lithofacies/hydrofacies and their correlation in space to obtain nearly homogeneous subunits starting from available data (i.e. 8628 borehole logs, grain size distributions, well tests) and sedimentological knowledge. New hydrological insights for the region: The calibrated 3D FEM groundwater model allows quantifying the main components of the hydrogeological budget at the regional scale, and the fluxes among the different hydro-stratigraphic units. A sensitivity analysis of groundwater levels to the main recharge components suggests importance of anthropogenic disturbances with respect to natural recharge, and that land-use change may impact water resources more than climate change

    Distinctive anthocyanin accumulation responses to temperature and natural UV radiation of two field-grown (<i>Vitis vinifera</i> L.) cultivars

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    The responses of two red grape varieties, Bovale Grande (syn. Carignan) and Cannonau (syn. Grenache), to temperature and natural UV radiation were studied in a three-years field experiment conducted in Sardinia (Italy), under Mediterranean climate conditions. Vines were covered with plastic films with different transmittances to UV radiation and compared to uncovered controls. Light intensity and spectral composition at the fruit zone were monitored and berry skin temperature was recorded from veraison. Total skin anthocyanin content (TSA) and composition indicated positive but inconsistent effects of natural UV light. Elevated temperatures induced alterations to a greater extent, decreasing TSA and increasing the degree of derivatives acylation. In Cannonau total soluble solids increases were not followed by increasing TSA as in Bovale Grande, due to both lower phenolic potential and higher sensitivity to permanence of high temperatures. Multi linear regression analysis tested the effects of different ranges of temperature as source of variation on anthocyanin accumulation patterns. To estimate the thermal time for anthocyanin accumulation, the use of normal heat hours model had benefit from the addition of predictor variables that take into account the permanence of high (&gt;35 °C) and low (&lt;15 °C and &lt;17 °C) temperatures during ripening

    Torre Alfina Deep Geothermal Reservoir

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    The Castel Giorgio-Torre Alfina (CG-TA, central Italy) is a geothermal reservoir whose fluids are hosted in a carbonate formation at temperatures ranging between 120°C and 210°C. Data from deep wells suggest the existence of convective flow. We present the 3D numerical model of the CG-TA to simulate the undisturbed natural geothermal field and investigate the impacts of the exploitation process. The open source finite-element code OpenGeoSys is applied to solve the coupled systems of partial differential equations. The commercial software FEFLOW® is also used as additional numerical constraint. Calculated pressure and temperature have been calibrated against data from geothermal wells. The flow field displays multicellular convective patterns that cover the entire geothermal reservoir. The resulting thermal plumes protrude vertically over 3 km at Darcy velocity of about  m/s. The analysis of the exploitation process demonstrated the sustainability of a geothermal doublet for the development of a 5 MW pilot plant. The buoyant circulation within the geothermal system allows the reservoir to sustain a 50-year production at a flow rate of 1050 t/h. The distance of 2 km, between the production and reinjection wells, is sufficient to prevent any thermal breakthrough within the estimated operational lifetime. OGS and FELFOW results are qualitatively very similar with differences in peak velocities and temperatures. The case study provides valuable guidelines for future exploitation of the CG-TA deep geothermal reservoir

    A multianalytical approach to investigate stone biodeterioration at a UNESCO world heritage site: the volcanic rock-hewn churches of Lalibela, Northern Ethiopia.

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    A multianalytical approach combining Optical Microscopy (OM), Backscattered Variable Pressure Scanning Electron Microscopy + Energy Dispersive X-ray Spectroscopy (VP-BSEM + EDS), Powder X-ray Diffractometry (PXRD), Raman Spectroscopy, and Microbiological techniques has been applied to characterize decay products and processes occurring at the surface of two rockhewn churches (Bete Gyorgis and Bete Amanuel) at the UNESCO’s World Heritage site of Lalibela, Northern Ethiopia. The two churches were carved into volcanic scoria deposits of basaltic composition. In their geological history, the Lalibela volcanic rocks underwent late to post-magmatic hydrothermal alteration together with partial laterization and are therefore characterized by a decay-prone highly vesicular microtexture with late stage to post-magmatic precipitation of secondary mineral phases (calcite–zeolite–smectite). The main objective of the study was to gain a better insight into the weathering products and mechanisms affecting the surface of the stone monuments and to assess the relative contribution of natural “geological” weathering processes versus biological/salt attack in stone decay at this unique heritage site. Results indicate that while the main cause of bulk rock deterioration and structural failure could be related to the stone inherited “geological” features, biological attack by micro- (bacteria) and/or macro- (lichens) organisms is currently responsible for severe stone surface physical and chemical weathering leading to significant weakening of the stone texture and to material loss at the surface of the churches walls. A prompt and careful removal of the biological patinas with the correct biocidal treatment is therefore recommended

    A multianalytical approach to investigate stone biodeterioration at a UNESCO world heritage site: the volcanic rock-hewn churches of Lalibela, Northern Ethiopia.

    Get PDF
    A multianalytical approach combining Optical Microscopy (OM), Backscattered Variable Pressure Scanning Electron Microscopy + Energy Dispersive X-ray Spectroscopy (VP-BSEM + EDS), Powder X-ray Diffractometry (PXRD), Raman Spectroscopy, and Microbiological techniques has been applied to characterize decay products and processes occurring at the surface of two rockhewn churches (Bete Gyorgis and Bete Amanuel) at the UNESCO’s World Heritage site of Lalibela, Northern Ethiopia. The two churches were carved into volcanic scoria deposits of basaltic composition. In their geological history, the Lalibela volcanic rocks underwent late to post-magmatic hydrothermal alteration together with partial laterization and are therefore characterized by a decay-prone highly vesicular microtexture with late stage to post-magmatic precipitation of secondary mineral phases (calcite–zeolite–smectite). The main objective of the study was to gain a better insight into the weathering products and mechanisms affecting the surface of the stone monuments and to assess the relative contribution of natural “geological” weathering processes versus biological/salt attack in stone decay at this unique heritage site. Results indicate that while the main cause of bulk rock deterioration and structural failure could be related to the stone inherited “geological” features, biological attack by micro- (bacteria) and/or macro- (lichens) organisms is currently responsible for severe stone surface physical and chemical weathering leading to significant weakening of the stone texture and to material loss at the surface of the churches walls. A prompt and careful removal of the biological patinas with the correct biocidal treatment is therefore recommended

    Internet Addiction: a prevention action-research intervention

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    The aim of this paper was to present an action-research intervention for the prevention of Internet addiction (IA) in schools. Applying a pre-experimental research design model, a total of 90 young subjects (45 males and 45 females) were treated using a peer education programme. The Internet Addiction Test was used as a screening tool pre- and post-treatment and analysed using a paired t-test. The results showed a significant positive difference in the post-treatment values for both males and females. This research highlights the link between IA and cultural and social aspects of the disease in addition to discussing the difficulties of IA prevention.&nbsp

    Micro-computed tomographic evaluation of endodontic ledge position in relation to canal curvatures.

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    BACKGROUND Endodontic ledge (EL) formation is the most common complication of endodontic treatment. Although various etiological factors have been identified, canal curvature is the most significant variable correlated with EL formation. The aim of this micro-computed tomographic (micro-CT) study was to evaluate EL position in the mesial canals of the lower molars in relation to the degree of canal curvature. METHODS Forty intact mandibular first molars with independent mesial canals with 20°-40° primary mesio-distal curvature, 10°-30° buccal-lingual canal curvature and 4 < r ≤ 8 mm main curvature radius were selected. Working length was measured with a K-File #10 and a high resolution pre-operative micro-CT analysis was performed. Ledges were created at the point of maximum canal curvature using stainless steel K-Files #30-35, alternating irrigation with 5% NaOCl and 10% EDTA. A post-operative high-resolution micro-CT analysis was then completed. Pre- and post-operative images were analyzed. The angle (α) formed between the vector passing through the geometric center of the EL and the center of the original canal lumen and the line joining the centers of the mesio-buccal and mesio-lingual canal orifices was calculated, and a descriptive statistical analysis was achieved. The α angle values were analyzed in relation to canal curvature using Kruskal-Wallis and post hoc Dunn's tests. The level of significance was set at P < 0.05. RESULTS The α angles appeared inversely proportional to canal curvatures in the buccal-lingual and mesio-distal projections. The mean α angle was 36.4° (standard deviation 10.64; 95% confidence interval 34.1-40.9). CONCLUSION Within the limitations of this study, endodontic ledges develop in the opposite direction to the three-dimensional canal curvature and their position is influenced by the degree of curvature. Clinically, the α angle values may be related to the recommended direction to manage endodontic ledges

    Ketogal: A Derivative Ketorolac Molecule with Minor Ulcerogenic and Renal Toxicity

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    Ketorolac is a powerful non-steroidal anti-inflammatory drug (NSAID), with a great analgesic activity, present on the Italian market since 1991. Despite the excellent therapeutic activity, the chronic use of ketorolac has long been limited owing to the high incidence of gastrointestinal and kidney side events. In our previous study, we demonstrated that ketorolac–galactose conjugate (ketogal), synthesized and tested in a single-dose study, was able to reduce ulcerogenicity, while preserving the high pharmacological efficacy of its parent drug. In this paper, in order to verify the suitability of this compound, for repeated administration, ex vivo experiments on naïve mice were performed. Mice were treated for 5 or 7 days with the highest doses of two drugs (ketorolac 10 mg/kg and ketogal 16.3 mg/kg), and the expression of both gastric COX-1 and PGsyn was evaluated. Results showed that oral ketorolac treatment significantly reduced both enzymes; surprisingly, oral treatment with ketogal did not produce significant variation in the expression of the two constitutive enzymes. Moreover, histological experiments on stomach and kidneys clearly indicated that repeated administration of ketogal induced lower toxicity than ketorolac. At same time, in vivo results clearly showed that both ketorolac and ketogal had a similar therapeutic activity in a model of inflammation and in pain perception. These effects were accompanied by the reduction of enzyme expression such as COX-2 and iNOS, and by the modulation of levels of nuclear NF-kB and cytosolic IkB-a in the inflamed paws. These very encouraging results demonstrate for the first time that ketogal could represent a valid and novel therapeutic alternative to the ketorolac and might pave the way for clinical studies
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