633 research outputs found

    Relations between static-structural aspects, construction phases and building materials of San Saturnino Basilica (Cagliari, Italy)

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    The construction site was used several times: in a first phase, in the republican era of Roman domination it hosted, probably, a temple whose height could reach 25 meters; in a second phase, during the Roman Empire, it was used as a burial area. Then around IV-V century AD a first Christian Basilica made of a naved building with an apse was built there, at the center of a large monastery. Subsequently in a third phase in VI century AD a Byzantine Martyrium, with a Greek cross-shaped plan, was built: the central part of it, supporting a dome is still standing. Finally after 1089 the church was given to Marsilian monks who deeply renovated it and changed its shape converting the plan to a Latin cross. A macroscopic material analysis shows the presence of various rocks, whose use appears to be inhomogeneous during all construction phases. Sedimentary rocks (limestones, sandstones, calcarenites etc belonging to local geological formations) are generally used for masonry structures. Marbles, mostly coming from abroad and previously used in Roman buildings have been adopted for architectural elements (columns, capitals, and so on). At a lower extent there are masonry blocks in Oligo-Miocenic volcanic rocks and seldom stone materials which are not originally from Sardinia. Both mineralogical and petrographic tests (e.g. XRF, XRD) and the most important physical properties (porosity, density, water absorption coefficients, compressive, flexural and tensile strength, etc) show that many of the more representative samples of rock materials (like limestonss, calcarenits) are often highly decayed, with a corresponding reduction of their mechanical strength. A structural analysis is particularly useful for helping in clarifying the historical evolution of the building, checking reconstruction hypotheses and assessing the true residual strength of the more important parts. An example, a FEM analysis of the Byzantine domed part is presented here

    From direct to digital survey. The Abbey of San Giovanni Battista in Lucoli (L' Aquila)

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    [EN] Lucoli is a scattered municipality in the area of L Aquila, in the Italian region of Abruzzo. In this place between the mountains of the conca Aquilana stands the Abbey of San Giovanni Battista, an important historic and religious site. Despite the damage suffered caused during the 2009 earthquake, the local people still use it and look at it as a symbol of community. With the aim of analyse and so mitigate the seismic vulnerability, the abbey has been the subject of an architectural survey with direct method in a first step, and then of digital laser scanning survey at a later stage, to integrate and verify the first.Brusaporci, S.; Ruggieri, A. (2022). From direct to digital survey. The Abbey of San Giovanni Battista in Lucoli (L' Aquila). EGE Revista de Expresión Gráfica en la Edificación. (17):56-71. https://doi.org/10.4995/ege.2022.1890256711

    Psychological Trust Dynamics in Climate Change Adaptation Decision-Making Processes: A Literature Review

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    There has been a growth in interest among academics and professionals in psychological trust dynamics during climate change adaptation. This literature review aimed to examine the research concerning trust dynamics in climate change adaptation from different levels of analysis, encompassing the different phases of adaptation and considering the importance of trust in climate change decision-making. The method consisted of systematically reviewing researches on this topic published in scientific articles, by using appropriate and relevant search keywords (e.g., trust, community, natural hazard, climate change adaptation, decision-making) in academic databases. A total of 25 studies met inclusion criteria. All the articles focused on the latter phases of the climate change adaptation cycle, specifically implementation and monitoring/evaluation, with limited attention devoted to decision-making related to earlier phases of preparation, assessment of risks, and identification and selection of adaptation options. The reviews also indicates that psychological trust is related to different adaptive actions (e.g., adoption of renewable energy technologies), and low- and high-impact mitigation behaviors (e.g., acceptance of paying taxes for actions that mitigate climate change). Therefore, this review underscores the significant role of psychological trust dynamics in shaping individuals’ decision-making processes concerning climate change adaptation, thereby yielding immediate and direct implications for climate systems. Therefore, it is essential to actively promote the culture of trust within the context of climate change adaptation

    Stability and Stiffness Contribution of the Masonry in the Borbone Anti-seismic System

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    Grotta dell\u2019Acqua Mintina a peculiar geosite with the smell of sulfur

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    Riassunto La grotta dell\u2019Acqua Mintina (comune di Butera, Caltanissetta, Sicilia) si estende per una lunghezza totale di 140 m nel Calcare di Base di et\ue0 messiniana (Miocene superiore) ed \ue8 caratterizzata dalla spettacolare presenza di concrezioni e cristalli di zolfo nativo e gesso secondario. Lo zolfo si \ue8 formato sulle pareti e sul soffitto della grotto in cristalli fino a 1 cm di lunghezza e in concrezioni microcristalline di forma botroidale, a nuvola, a popcorn e a \u201cmensola\u201d. Il gesso \ue8 presente in aggregati cristallini aciculari, prismatici e fibrosi con cristalli fino a 3 cm di lunghezza. La grotta mostra morfologie non compatibili con i consueti fenomeni carsici ma legate ad attacco acido su calcare. L\u2019acido solforico \ue8 stato generato in corrispondenza della falda acquifera per miscelazione di acque ricche di H2S risalite dai sedimenti sottostanti con acque ricche in ossigeno infiltrate dalla superficie. Il gesso si \ue8 formato attraverso il fenomeno della condensazione-corrosione di acido solforico sulle pareti calcaree della grotta, mentre lo zolfo si \ue8 formato per degassamento di H2S e CO2 al di sotto della superficie dell\u2019acqua, con parziale ossidazione dell\u2019acido solfidrico. L\u2019acido solfidrico \ue8 stato a sua volta generato dalla degradazione dei sedimenti ricchi in materia organica del Tripoli che si trovano immediatamente al di sotto del Calcare di Base e/o per riduzione batterica del gesso primario della Formazione di Pasquasia affiorante al di sopra. La grotta, per la presenza di spettacolari concrezioni di zolfo e gesso, rappresenta un geosito di interesse nazionale da tutelare e conservare attivamente.The Acqua Mintina cave (Butera, Caltanissetta, Sicily) cuts for a total length of 140 m the Messinian Calcare di base unit and is characterized by the spectacular, and fortunately still poorly degraded, presence of native sulfur and secondary gypsum. The sulfur occurs on the walls and ceiling in crystals up to 1 cm in length and centimeter-thick microcrystalline botroydal, cloud, popcorn, and folia concretions. Gypsum is present in acicular, prismatic and fibrous crystal aggregates consisting of crystals of up to 3 cm in length. The cave shows karst morphologies due to acid attack on limestone and not the usual dissolution by water flow. The organic-rich Tripoli sediments below the Calcare di Base unit and/or the bacterial reduction of gypsum from the Upper Gypsum unit probably provided the original H2S. Sulfuric acid was generated when H2S-rich water encountered oxygen-rich water at or near the water table. Gypsum formed by condensation-corrosion of sulfuric acid on the cave walls, while the sulfur concretion probably formed where H2S and CO2 were outgassing below the water surface, with the H2S partially oxidizing to sulfur. The cave for its widespread presence of spectacular crusts of sulfur and gypsum crystals represents a rare and valuable geosite to be actively protected and preserved

    Cortical and subcortical brain alterations in Juvenile Absence Epilepsy

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    Despite the common assumption that genetic generalized epilepsies are characterized by a macroscopically normal brain on magnetic resonance imaging, subtle structural brain alterations have been detected by advanced neuroimaging techniques in Childhood Absence Epilepsy syndrome. We applied quantitative structural MRI analysis to a group of adolescents and adults with Juvenile Absence Epilepsy (JAE) in order to investigate micro-structural brain changes using different brain measures. We examined grey matter volumes, cortical thickness, surface areas, and subcortical volumes in 24 patients with JAE compared to 24 healthy controls; whole-brain voxel-based morphometry (VBM) and Freesurfer analyses were used. When compared to healthy controls, patients revealed both grey matter volume and surface area reduction in bilateral frontal regions, anterior cingulate, and right mesial-temporal lobe. Correlation analysis with disease duration showed that longer disease was correlated with reduced surface area in right pre- and post-central gyrus. A possible effect of valproate treatment on brain structures was excluded. Our results indicate that subtle structural brain changes are detectable in JAE and are mainly located in anterior nodes of regions known to be crucial for awareness, attention and memory
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