1,721,059 research outputs found
Indagini preliminari sui sistemi di approvvigionamento idrico nell’area dell’Insula I di Capo Boeo (Marsala, Sicilia occidentale)
No full textThe Insula I of Capo Boeo, a Roman-imperial Domus in the Archaeological Park of Marsala (Trapani province), now appears
to be occupied by a single house from the III century A.D. The Domus was surrounded by a peristyle with columns
that bordered an inner garden, around which the reception rooms opened, enriched with high-quality details such as
stucco, mosaics and thermal baths. In this site of great importance, in-depth studies have been carried out aimed to detecting and analyzing the ancient structures, proposing reconstructive hypotheses, and identifying the function of the various sectors. As part of these studies, authorized by the Regional Pole of Trapani and Marsala for the Cultural Sites and the
Direction of the Archaeological Park, investigations were carried out into the man-made cavities of the Insula I. The investigated
cavities, used for collecting or draining water, often are waterproofed with cocciopesto mortars both in the walls and,
occasionally, at the roof
Some Considerations on 3-D and 2-D Numerical Models for the Assessment of the Stability of Underground Caves
No full textThe application of numerical modeling to the analysis of the stability of both natural and manmade
underground caves is rapidly increasing due to the availability of powerful numerical
codes, that can account for either continuum or discontinuum behavior of the rock masses.
Numerical methods allow to overcome traditional methods for cave stability analysis that
assume too simplified geometrical, geological and geomechanical conditions. Further, they are
also able to assess the potential failure mechanisms of underground systems. On the other hand,
the application of numerical methods requires availability of a detailed geo-structural survey of
the cave, as well as a proper geomechanical characterization of the rock and joint material
properties for the pre-processing stage. The present contribution is aimed at describing some
aspects related to implementation, and comparison of the outcomes, of two-dimensional or
three-dimensional finite element analysis as regards artificial caves with complex geometries
excavated within calcarenite rock masses. This type of man-made caves is very common in
Southern Italy, and is at the origin of frequent sinkholes, often threatening the built-up areas. In
particular, the results from 2-D and 3-D analyses of a case study represented by a cave with
complex geometry are presented, showing that 3-D analysis leads to more stable conditions of
the rock mass surrounding the cave. This is supposed to be the consequence of the different
stress state as calculated by the two analyses, the 2-D one assuming plane strain conditions
while the 3-D analysis assumes more general stress conditions
Il carsismo nei gessi della Sicilia occidentale
No full textViene proposto un itinerario che consente di osservare alcune delle aree carsiche gessose più significative dell’intero Bacino del Mediterraneo per la eccezionale varietà e ricchezza di morfologie carsiche sia superficiali che sotterranee in esse presenti. L’itinerario si sviluppa in Sicilia occidentale e centro-meridionale e si articola in tre percorsi che possono essere realizzati in tre giorni, attraverso l’utilizzo dell’auto e tratti a piedi. Alcune delle aree, per la loro valenza scientifica e paesaggistica, costituiscono delle riserve naturali, istituite dalla Regione Sicilia, e/o Zone Speciali di Conservazione (ZSC) e Zone di Importanza Comunitaria (SIC)
Statistical approach for cavity detection using seismic refraction and electrical resistivity data
No full textTo test limitations and effectiveness of seismic tomography when coupled to geoelectrical technique for cavity detection 2D synthetic models were used. Synthetic models were created with different number of cavity and blocks of highly cohesive lithological material (high seismic velocity and resistivity values). A modified version of multiple gradient (Martorana et al., 2016) has been used for electrical sequence. The cluster analysis performed on static units defined by electrical resistivity values, P wave velocities, and seismic density on coincident sections, allowed to interpret subsoil structures. The use of the non-hierarchical clustering algorithm has been chosen because it is less influenced by abnormal values, and allows a statistical unit to change its cluster during the iterative process.
Depending on the choice of the number of clusters to be identified, cluster distribution maps have been constructed in the multi-parameter space, allowing defining certain variability limits
for the selected parameters, for synthetic and experimental data. Finally, experimental data show that electrical and seismic tomographies is not influenced by the presence of cavities
without lateral continuity
Riscoperta di alcuni ipogei artificiali nel Comune di Sutera (Caltanissetta, Sicilia centrale)
No full textGrazie ad approfondite ricerche di archivio e accurate indagini speleologiche, sono stati ispezionati e documentati diversi ipogei artificiali presenti nel comprensorio di Sutera (CL). L’area di Sutera, caratterizzata da affioramenti evaporitici messiniani e non lontana da importanti miniere di salgemma e di zolfo, ha subito una veloce corsa verso la ricerca di minerali pregiati intorno ai primi del ‘900. A memoria di queste attività sono rimaste diverse tipologie di cavità, quali: gallerie di carreggio, discenderie per ricerca mineraria, ma anche antiche cisterne per la raccolta d’acqua dove recentemente, a seguito
di operazioni di ripristino e pulizia, sono stati effettuati importanti ritrovamenti archeologici. In questo contributo verranno descritti alcuni degli ipogei rinvenuti, mettendone in evidenza la tipologia e lo stato di conservazioneIn the Sutera (CL) area several man-made cavities were explored and studied after extensive archive researches and accurate speleological investigations. The Sutera area, characterized by evaporitic Messinian outcrops and not far from important salt and sulfur mines, underwent
a rapid race to the mining activity in the early 1900s. Different types of cavities occur as memory of the mining practice, such as: carriageway tunnels, descendants for mining research, and old rainwater collection cisterns. In the biggest cistern restoration and cleaning activities led to discover important archaeological finds. Aim of this paper is to describe some explored underground cavities highlighting their typology and state of conservation
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
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Anthropogenic sinkholes in the Marsala area (western Sicily) linked to underground quarries
Full text linkMarsala territory (western Sicily) is characterized by the presence of a Lower Pleistocene (Calabrian) calcarenite
succession (Marsala Calcarenite Fm). It can be divided into three lithofacies that show the regressive evolution
of the depositional system: a) coarse to fine yellow bio- and lithoclastic calcarenites, b) sands, and c) gray sandy
clays. At least 80 m-thick, this succession gently dips (5-10) towards the south and the south-west. At some
locations the Marsala Calcarenite is covered by Middle and Upper Pleistocene marine terraced deposits.
Since the Roman period, due to the great abundance of calcarenite rocks, and to the facility of extraction, the
Marsala area has been characterized by a high number of quarries for the extraction of this building materials.
Many of them were excavated underground, at depth varying from a few meters to about 25 m, and are arranged
in one or two levels, following the galleries and pillars excavation technique. With time, the underground quarries
have been progressively abandoned for the decay of the physical and mechanical properties of the calcarenite
rock mass, the interaction with the groundwater, the high costs of extraction, and the dangers and difficulties
encountered in working underground.
Since the 1960’s the quarries have been affected by instability processes, visible through collapses and deformations
of vaults and pillars. These phenomena often propagate upward reaching the topographic surface and
forming sinkholes which affect and severely damage the built-up area.
In particular, two case studies of sinkholes related to different underground quarries will be analyzed in this paper.
The aim is to provide a description of the most significant processes and factors responsible of the instability
processes based on field surveys, as well as to understand the generation mechanisms of these anthropogenic
sinkholes by means of numerical modeling, based on rock laboratory testing data, that represents in these cases
a remarkable tool for the investigation of the cause-effect relationships, as already performed in other areas of Italy
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