115,938 research outputs found
L'operosità umana dalla terra al mare: il caricatore di Sciacca tra XIV e XV secolo
No full textIl saggio ricostruisce il funzionamento del caricatore di Sciacca nel tardo Medioevo e la sua attività negli anni del regno di Alfonso V, sulla base dei registri del maestro portulano, conservati presso l’Archivio di Stato di Palermo. L’esame dei conti del maestro portulano ha fatto emergere interessanti notizie relative all’attività del caricatore, ai titolari degli uffici, agli assegnatari delle tratte, alla nazionalità dei mercanti coinvolti nelle esportazioni, alla quantità e tipologia delle merci esportate, alle destinazioni. I dati emersi confermano la collocazione del caricatore di Sciacca tra i maggiori porti frumentari siciliani del XV secolo
Offshore 3D geological model of the 628 Sheet “Sciacca” (Progetto CARG)
No full textThe offshore sector of southwestern Sicily, as represented in the Sheet 628 “Sciacca”, is part of the external
segment of the Sicilian Fold-and-Thrust Belt (SFTB) and has recorded a complex geological evolution. The
integration of marine geophysical data, seismic stratigraphy, and well-log interpretations has allowed for a
detailed reconstruction of the 3D geological model down to a depth of 5 km, correlating tectonic structures
between offshore and onshore sectors.
The main stratigraphic setting of this sector consists of Meso-Cenozoic carbonate successions (Saccense
domain) overlain by Neogene-Quaternary syntectonic deposits, with the Pleistocene terrigenous sediments
recording the most recent tectonic deformation.
The regional Neogene to Quaternary tectonic evolution of this sector of the SFTB is defined by a multistage
deformation history: i) Messinian to Early Pliocene compressional event resulted in south-east vergent
folds in the post-early Jurassic portion of the sedimentary succession with local decollement surfaces at
different stratigraphic intervals, ii) the Late Pliocene–Early Pleistocene compressional stage generated highangle
thrusts responsible for the exhumation of main carbonate reliefs and the development of the a new
forward thrust system named Gela Thrust Wedge; this last was also responsible for the occurrence of structures
generated by gravity processes; iii) a post-Early Pleistocene compressional-transpressional event activated
major tectonic structures, including a conjugate NNE-SSW-oriented left-lateral transpressive fault (pop-up
structure). This structure is recognizable in the western offshore sector (Capo San Marco).
The integration of seismic-stratigraphic and structural data has provided insights into the linkage between
deep and shallow geological structures. The gravimetric anomaly map reveals a NE-SW-trending positive
Bouguer anomaly, consistent with subsurface tectonic features. Heat flux data confirm the relationship between
deep aquifer systems within fractured Mesozoic carbonates and offshore fluid escape structures, linking the
Sciacca Geothermal Field to offshore thermal anomalies.
Analysis of high-resolution single channel seismic profiles provided for a detailed assessment of most
recent tectonic activity, that is responsible for NNE-SSW trending high angle faults affecting the seabed, as
well as pockmarks, chimneys, and gas flares, concentrated in the western and central offshore sector (Capo
San Marco and Verdura River mouth, and indicating active fluid migration. These morphological features are
strongly correlated with the most recent buried tectonic structures here reconstructed, providing evidence of
active tectonics. Finally, the 3D geological model has delineated the extent, thickness, and fault boundaries
of buried tectonic units, refining our understanding of the region’s tectonic evolution and the relationships
between deep geological structures and seabed morphological features
Sciacca tra XIV e XV secolo: uno spaccato di vita nel Castello Nuovo
No full textIl saggio, attraverso l'esame di un inventario inedito della metà del XV secolo, ricostruisce uno spaccato di vita medievale nel castello nuovo di Sciacca, costruito da Guglielmo Peralta, conte di Caltabellotta, e ripercorre la storia dei signori di Sciacca che nel castello hanno risieduto nel XIV e XV secolo, i Peralta e i Luna
Sciacca teoreta e apologeta
No full textIl rapporto tra filosofia e religione nella teoresi sciacchian
Fluid-Related Features in the Offshore Sector of the Sciacca Geothermal Field (SW Sicily): The Role of the Lithospheric Sciacca Fault System
No full textThe Sciacca basin extends in the southwestern part of Sicily and hosts an important
geothermal field (the Sciacca Geothermal Field) characterized by hot springs containing mantle
gasses. Newly acquired high-resolution seismic profiles (Boomer data) integrated with a multichannel
seismic reflection profile in close proximity to the Sciacca Geothermal Field have documented the
presence of numerous active and shallow fluid-related features (pipes, bright spots, buried and
outcropping mud volcanoes, zones of acoustic blanking, and seafloor fluid seeps) in the nearshore
sector between Capo San Marco and Sciacca (NW Sicilian Channel) and revealed its deep tectonic
structure. The Sciacca Geothermal Field and the diffuse submarine fluid-related features probably
form a single onshore–offshore field covering an area of at least 70 km2. This field has developed
in a tectonically active zone dominated by a left-lateral transpressive regime associated with the
lithospheric, NNE-striking Sciacca Fault System. This structure probably favored the rising of magma
and fluids from the mantle in the offshore area, leading to the formation of a geothermal resource
hosted in the Triassic carbonate succession that outcrops onshore at Monte San Calogero. This field
has been active since the lower Pleistocene, when fluid emissions were likely greater than today and
were associated with greater tectonic activity along the Sciacca Fault Syste
Improved outflow model for oil tankers following collision events and investigation of relevant statistical properties by Monte Carlo simulation
No full textThe paper focuses on the development of an improved outflow model for oil tankers following collision events and the investigation of its statistical properties by Monte Carlo simulation. After a review of the most recent advances, a new oil outflow model is developed for double hull oil tankers, based on a time-domain iterative procedure, until hydrostatic equilibrium is reached at outer and inner side openings. The model allows removing the assumptions related to the negligible dimension of the damaged area, the full loading condition of cargo tank and the detachment of the oil spillage event in a set of subsequent phases. The IMO statistics are employed for random generation of collision damage events, under different assumptions concerning the damage dimensions, assumed both uncorrelated and correlated, in the latter case by the employment of Gaussian copula functions. Two oil tankers are considered in a benchmark study, devoted to investigating the oil outflow statistical properties following collision events and comparing them with the relevant values obtained by the IMO model. The incidence of double hull width is investigated and some suggestions for the possible updating of current IMO guidelines are also provided to improve the safety of oil tankers following collision events
Analytic Solutions and Singularity Formation for the Peakon b-Family Equations
No full textThis paper deals with the well-posedness of the b-family equation in analytic function spaces. Using the Abstract Cauchy-Kowalewski theorem we prove that the b-family equation admits, locally in time, a unique analytic solution. Moreover, if the initial data is real analytic and it belongs to H s with s>3/2, and the momentum density u 0-u 0, xx does not change sign, we prove that the solution stays analytic globally in time, for b≥1. Using pseudospectral numerical methods, we study, also, the singularity formation for the b-family equations with the singularity tracking method. This method allows us to follow the process of the singularity formation in the complex plane as the singularity approaches the real axis, estimating the rate of decay of the Fourier spectrum
“Ci sono più cose in cielo e in terra...” Due metodologie diverse per investigare il passato: il Castello Nuovo di Sciacca tra storia e archeologia
No full textLa storia di Sciacca e del Castello Nuovo, ricostruita sulle fonti documentarie, riceve nuova luce dalle indagini condotte dalla Soprintendenza di Agrigento nel butto del castello, che ha restituito importanti testimonianze di cultura materiale. Il contributo, attraverso la lettura sinottica dei dati archeologici ed archivistici, offre un quadro della vita quotidiana al castello tra il XIV ed il XVI secolo, quando Sciacca con il suo caricatore riveste un ruolo di primo piano nel commercio mediterraneo.The history of Sciacca and Castello Nuovo documented by archival sources and further enriched by the researches conducted by Soprintendenza of Agrigento is in the dump of the castle, which has yielded important evidence for its material culture. The paper proceeds through the synoptic reading of the archaeological and archive data, offers a pattern of daily life at the castle from the 14th to the 16th century, when Sciacca with its port plays a leading role in Mediterranean trade
Discrete KP Equation and Momentum Mapping of Toda System
No full textA new approach to discrete KP equation is considered, starting from the Gelfand-Zakhharevich theory for the research of Casimir function for Toda Poisson pencil. The link between the usual approach through the use of discrete Lax operators, is emphasized. We show that these two different formulations of the discrete KP equation are equivalent and they are different representations of the same equations. The relation between the two approaches to the KP equation is obtained by a change of frame in the space L-n of upper truncated Laurent series and translated into the space D-n of shift operators
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