1,721,039 research outputs found
Reconstruction, recovery and socio-economic development of the Basilicata region, southern Italy: lessons and experience after the 1980 earthquake
No full textIn the present paper, a critical analysis of the 1980 Irpinia-Basilicata (southern Italy) post-earthquake phase has been carried out, with particular attention to the Basilicata region. Post-earthquake policies were mainly addressed towards the physical reconstruction and socio-economic development of the affected areas. As for the development process, the expected results from the industrialisation and infrastructure works have been rather poor or indeed not achieved, mainly as a consequence of red tape, inefficiency and sometimes corruption events. On the other hand, impressive steps ahead have been made in terms of knowledge advancement concerning the assessment and reduction of seismic risk, with the creation of important education and research institutions in Basilicata. Furthermore, the relationship between earthquake disaster and territorial development has been examined, starting from some prominent studies proposed in the literature. The evolution of vulnerability levels to earthquakes of some countries around the world have been evaluated. Specifically, considering a time span of about 40 years (1980-2020), the data related to the number of deaths caused by earthquakes with respect to the population exposed has been analysed and some comparisons have been carried out. Although limited, since referring to a single risk indicator, the results confirm the close link between seismic consequences and socio-economic characteristics of the affected communities, as a poignant lesson for planning effective risk mitigation strategies
Seismic rehabilitation of residential buildings: An action plan for the urban centres in Val d’agri, Italy
No full textThe paper deals with a highly seismic area located in the SW of the Basilicata region (southern Italy), along the valley of the Agri River. This area has a strategic role for Italy because about 70% of the Italian oil extraction derives from local deposits. Large quantities of oil have been extracted since the 1990s, making available large resources deriving from royalties. These sums of money could be used for an extensive strengthening program able to reduce the impact of future earthquakes. To this end, an action plan for the seismic risk mitigation of the residential building stock of 18 villages located in the Agri Valley is outlined, and specifically applied to the village of Viggiano. Starting from the available building-by-building inventory of the typological characteristics collected during previous research activities, the seismic vulnerability of the whole building stock is studied and the expected losses deriving from an earthquake scenario are determined. Some directions for an action plan, essentially based on the reduction of seismic vulnerability of buildings, are proposed in terms of needed costs and implementation timetables
Polyamine content and metabolism as markers of in vitro organogenesis in cotyledon explants of Solanum melongena
No full textIn the present work changes in free and conjugated polyamine titres were determined in in vitro cultured cotyledon explants of S. melongena L. growing either a) in the presence of auxin (NAA), b) in the presence of NAA plus a cytochinin (zeatin riboside, ZR), c) in the absence of exogenous hormones (control). In these explants, NAA induces the formation of adventitous roots, and NAA + ZR the formation of vegetative buds; on hormon-free medium there is no organ differentiation. The appearence of roots and buds was monitored during time in culture and a histological study was performed in order to determine the site and developmental sequence of organ initiation and development
Modelling exposure and vulnerability from post-earthquake survey data with risk-oriented taxonomies: AeDES form, GEM taxonomy and EMS-98 typologies
No full textCorrelations between macroseismic intensity estimations and ground motion measures of seismic events
No full textMacroseismic intensity data are an important source to learn from historical earthquakes. Nevertheless, this data needs to be converted into more suitable intensity measures to be used in risk analyses, as well as in design practice. To this purpose, in this paper, correlations between macroseismic scales and ground motion parameters have been derived. Peak Ground Acceleration (PGA), Peak Ground Velocity (PGV) and Housner Intensity (IH) as instrumental measures, and European Macroseismic Scale (EMS-98) and Mercalli-Cancani-Sieberg (MCS) as macroseismic measures, have been considered. 179 ground-motion records belonging to 32 earthquake events occurred in Italy in the last 40 years have been selected, provided that for each record, macroseismic intensity in terms of either EMS-98 or MCS or both were also available. Statistical analyses have been carried out to derive both direct (i.e. macroseismic vs instrumental intensity) and inverse (instrumental vs macroseismic intensity) relationships. Results obtained from the proposed relationships have been analyzed and compared with some of the most prominent results available in the technical literature
Relating Trait Variation to Species and Community Productivity in Contrasting Oro-Mediterranean Pastures: A 7-Years Study in the Pollino National Park (S-Italy)
Full text linkUnderstanding how functional traits influence community assemblage and functioning is crucial for assessing the effects of global change on vegetation composition. We studied the functional composition (i.e., plant size (SIZE), leaf area (LA), specific leaf area (SLA), and leaf dry matter content (LDMC)) of a xerophile pasture and a mesophile grassland in southern Italy, and recorded species richness (SR), plant cover (COV) and flowering rates (FLOW) over a 7-year period. Both communities revealed the dominance of stress-tolerators, probably reflecting an adaptation to the Mediterranean climate. The functional classification of species distinguished three groups. Species from the mesophile community had larger SIZE and LA, while those from the xerophile pasture showed higher LDMC; SLA was not connected to the source community. Community-level analyses confirmed such patterns, but with higher SLA in the mesophile grassland. While SR was comparable, COV and FLOW varied between the communities. At the species level, LDMC was positively related to FLOW and the inter-annual variability of COV and FLOW. At the community level, SIZE, LA and SLA were positively related to COV, while LDMC was positively related to FLOW. Trait variations can significantly contribute to the xerophile–mesophile shift in Mediterranean mountain vegetation, by regulating the productivity of species and communities in the two contexts and, possibly, their responsiveness to global change
Analysis of Damage to Buildings in Urban Centers on Unstable Slopes via TerraSAR-X PSI Data: The Case Study of El Papiol Town (Spain)
No full textPersistent Scatterer Interferometry (PSI) data, deriving from the processing of SAR images acquired by high-resolution sensors such as TerraSAR-X, provide accurate measurements of displacements affecting structures (e.g., buildings) and linear infrastructure networks (e.g., roads, bridges, embankments, and pipelines). Such widespread displacements, when available on buildings on unstable slopes, offer new perspectives for their integration in procedures pursuing the analysis and the prediction of the physical vulnerability of exposed buildings. In this letter, both deterministic and probabilistic cause (differential settlements)-effects (damage) relationships are generated by using PSI-derived building settlements and the results of building damage surveys. The procedure is applied to El Papiol town (Spain), whose urban area has been suffering diffuse damage of different severity to buildings and roads due to extremely slow-moving landslide phenomena
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
District-scale numerical analysis of settlements related to groundwater lowering in variable soil conditions
Full text linkThis study presents a novel framework in which numerical modelling contributes to the performance of district-scale, subsidence-induced damage assessment in cities where ground settlements affect entire quarters. Therein, the implementation of expeditious procedures offers geotechnical engineers the possibility of contributing beyond the typical site scale. For this purpose, several “typified” hydro-geomechanical-loading (HGL) models, which represent (simplified) scenarios of masonry buildings undergoing settlements, were set up to account for different predisposing or triggering factors (i.e., soil heterogeneity, loading conditions, and groundwater variations) of settlement occurrence in built-up areas. These models exploit multi-source, wide-area input datasets encompassing the hydro-mechanical properties of geomaterials, in situ investigations and measurements (e.g., groundwater levels in wells), and innovative remote sensing data (i.e., DInSAR techniques). With reference to a district in Rotterdam City (the Netherlands), which was built on “soft soils”, the numerical simulations of different scenarios (i) provide an overview of the comparative role of predisposing or triggering factors on settlement occurrence and (ii) allow assessments of the expected induced damage to masonry buildings over 30 years with the exploitation of fragility curves. Considering the widespread diffusion of such geohazards, the proposed approach could help prioritise (rather expensive) maintenance work to the built heritage within sustainable strategies for subsidence risk mitigation.Applied MechanicsGeo-engineerin
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