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This work is focused on the mechanical characterization and fracture surfaces analysis of thermosetting polymers reinforced with short, randomly oriented, recycled carbon fibres (rCFs). This work aims at evaluating fibre/matrix adhesion between recycled CFs-reclaimed via pyrolysis followed by controlled oxidation of the pyrolytic char-and different polymer matrices, namely epoxy and vinyl ester resins. The latter is the main focus in this work, being amongst the most widely used thermosetting resins in SMC processes, which are the typical target for short rCFs. The evaluation of the properties of this new recycled carbon fibre reinforced polymer (rCFRP) has been via thermogravimetric analysis, dynamic mechanical analysis, stress/strain tests in tensile mode, and a subsequent analysis of the fracture surfaces by means of images analysis obtained by macrophotography, Optical Microscopy and Scanning Electron Microscopy. The comparison amongst the results allowed to evaluate the influence of the polymer nature and of the adhesion quality between fibres and polymeric matrix, mainly on the mechanical properties of the rCFRPs.

Opportunely designed synthetic DNA molecules can spontaneously self-assemble into stable nanosized structures of desired shape, and can then assume a large variety of conformations in response to external stimuli [1]. By controlling both the structure and its conformations, its thus possible to obtain functional dynamic nano-structures capable of performing work in the nanoscale. We describe the computational and experimental characterization of a previously reported [2] nanomotor based on the controlled formation and breakdown of an intramolecular DNA triple-helix, and suggest its potential applications. The DNA molecular motor object of this report is driven by a fast and clean mechanism, based on the pH-dependent formation and breakdown of a CT-motif DNA triplehelix [3]. The repeated cycling of the pH between opportune values causes the adduct to intermittently assume a folded or open state, as experimentally confirmed by means of UV, CD and fluorescence spectroscopy, as well as an electrophoretic mobility shift assay. By means of silane chemistry, the nanomotor was then covalently anchored on glass surfaces, allowing for single-molecule fluorescence characterizations of its static and dynamic behaviour. This also confirmed that the smooth functioning of the nanomotor is possible in conditions that could hamper the performance of other DNA nanomotors, i.e. in sterically hindered contexts such as at surfaces, and suggesting that it might also work in other systems where diffusion is dominant and the mobility of the species involved in the cycling is critical, e.g. in nano-sized pores. A computational model of the nanomotor was created, that permitted the individuation of the intermediates occurring during the motors opening and closing events. [1] a) C. M. Niemeyer, M. Adler, Angew. Chem, Int. Ed. 2002, 41, 3779; b) B. Samorì, G. Zuccheri, Angew. Chem, Int. Ed. 2005, 44, 1166. [2] M. Brucale, G. Zuccheri, B. Samorì, Org. Biomol. Chem. 2005, 3, 575. [3] G. Felsenfeld, D. R. Davies, A. Rich, J. Am. Chem. Soc. 1957, 79, 2023.

Salt contamination in the coastlands surrounding Venice Lagoon (Italy) and Laizhou Bay (Shandong Province, China) is generally the result of the complex relationship between fresh, continental groundwaters, paleo-saltwaters in deep aquifers, marine waters, and the seawater encroachment upstream from the river mouths. Saltwater intrusion is also enhanced by the presence of ancient, sandy, buried paleo-channels that act as preferential pathways for groundwater flow and solute transport. The characterization of these hydro-geo-morphological features, considering both the architecture and the pore water quality, is an issue of paramount importance. In this work, after a short overview of the saltwater contamination occurrence that affects the coastlands of Venice Lagoon and Laizhou Bay, we report on the preliminary results of a Very High Resolution Seismic and Continuous Electrical Tomography test carried out in very shallow water (about 1 m) in the Venice Lagoon to test a technique suitable for the better understanding of the surficial-groundwater mixing process. The combined analysis of the two data sets highlights a correlation between lithostratigraphic discontinuities and heterogeneity in the fluid filling the subsurface. The promising results obtained in the Italian site support a prompt use of this integrated methodology on the Chinese study area too.

Nell'ambito del Programma di studio "La laguna di Venezia nel quadro dei cambiamenti climatici, delle misure di mitigazione ed adattamento e dell'evoluzione degli usi del territorio", il Progetto SHALLOWS "Indagini nel sottosuolo olocenico della laguna di Venezia" è stato avviato nel contesto dell'Attività: "Analisi delle componenti a scala locale del relative sea level rise alla luce degli scenari globali di sviluppo futuro considerati dall'IPCC". Questo progetto prevede l'estensione all'area lagunare centrale delle indagini del sottosuolo lagunare condotte nell'area meridionale dalla Linea di Ricerca 3.16, nel precedente programma di ricerca CORILA (2004-2006). Le indagini verranno principalmente condotte nei bassifondi attraverso rilievi sismici ad altissima risoluzione, analisi sedimentologiche e geomorfologiche. In particolare saranno investigati in dettaglio alcuni siti chiave dove sono presenti strutture geomorfologiche sepolte, ad esempio sistemi deltizi e di argine-canale. In questo articolo vengono presentati scopi ed obiettivi della ricerca e riportati alcuni esempi di risultati relativi alle indagini preliminare effettuate nella fase di programmazione delle campagne di rilevamento geologico.

Novel DNA derivatives have been recently investigated in the pursuit of modified DNA duplexes to tune the electronic structure of DNA-based assemblies for nanotechnology applications. Size-expanded DNAs (e.g., xDNA) and metalated DNAs (M-DNA) may enhance stacking interactions and induce metallic conductivity, respectively. Here we explore possible ways of tailoring the DNA electronic structure by combining the aromatic size expansion with the metal-doping. We select the salient structures from our recent study on natural DNA pairs complexed with transition metal ions and consider the equivalent model configurations for xDNA pairs. We present the results of density functional theory electronic structure calculations of the metalated expanded base-pairs with various localized basis sets and exchange-correlation functionals. Implicit solvent and coordination water molecules are also included. Our results indicate that the effect of base expansion is largest in Ag-xGC complexes, while Cu-xGC complexes are the most promising candidates for nanowires with enhanced electron transfer and also for on-purpose modification of the DNA double-helix for signal detection.

The contributions of eustasy and tectonics to the development of stratigraphic sequences are commonly hard to discern, and this has been a controversial topic that is still being debated. New data are therefore necessary to improve our understanding of the factors that govern sedimentary cyclicity. Data from the subsiding Venice and the uplifting Crotone areas in Italy allow the recognition of the different effects of Late Quaternary glacio-eustatic changes and regional tectonics on sequence architecture at different temporal scales. Shallow-marine small-scale sequences linked to short-term glacio-eustatic changes at the scale of the marine isotope substage cyclicity (10000 years) show features that developed irrespective of the local conditions of subsidence or uplift, such as a modest thickness, a similar organization of facies and thin transgressive deposits. In contrast, lower frequency composite sequences at the scale of 100000 years show strongly different architectures and stacking patterns depending on the regional tectonic context: downstepping in uplifting areas and aggradational in subsiding areas. The present results, therefore, highlight that only the architecture of small-scale sequences showing a periodicity of about 20 and 40 ka appears to be dominated by the glacio-eustatic variable, because of the very high rates of sea-level change characterizing the substage cyclicity, which overprints the regional tectonic signal.

A recent research has provided a high resolution map of the present land subsidence of the Venice coastland (Italy). The map, which refers to the 1992-2002 decade and covers an area of about 100x100 km2, has been obtained by the innovative "Subsidence Integrated Monitoring System" (SIMS) that efficiently merges the different displacement measurements obtained by spirit leveling, differential and continuous Global Positing System (GPS), Synthetic Aperture Radar (SAR)-based interferometry. The investigation points out a significant spatial variability of the ground vertical movements, both at regional and local scales, and displacement rates ranging from a slight (1-2 mm/yr) uplift to a serious subsidence of more than 10 mm/yr. Tectonics, differential consolidation of the Pleistocene and Holocene deposits, and human activities, such as groundwater withdrawals, land reclamation of marshes and swamp areas, and farmland conversion into urban areas, superimpose to produce the observed displacements. In this work we have distinguished the displacement components on the basis of the depth of their occurrence. Deep causes, acting at a depth generally greater than 400-600 m below m.s.l., refer to downward movements of the pre-Quaternary basement and land uplift (up to 2 mm/yr) most likely related to neo-tectonic activity connected with the Alpine thrust belts and a NW-SE fault system. The displacement factors located in the medium depth interval, i.e. between 400 and 50 m below m.s.l., are of both natural and anthropogenic origin. The former refers to the Medium-Late Pleistocene deposits that exhibit a larger cumulative thickness of clayey compressible layers at the lagoon extremities with respect to the central lagoon area where stiffer sandy formations prevail. Land subsidence due to aquifer exploitation mainly occurs in the north-eastern sector of the coastland where thousands of active wells are located. In a 10-15 km wide coastal strip thickness, texture, and sedimentation environment of the Holocene deposits play a significant role in controlling shallow land subsidence. Other factors that contribute in increasing land sinking at a smaller areal extent are the salinization of clay deposits due to saltwater intrusion and biochemical oxidation of outcropping peat soils enhanced by. Even the load of houses and structures after the conversion of farmland into urbanized areas cause local shallow compaction.

Le livellazioni geometriche sono state nel secolo scorso l'unico metodo di rilievo altimetrico che abbia consentito di misurare con precisione l'entità della subsidenza "moderna" dell'area costiera nord adriatica. Solo alla fine degli anni 1990 è stata istallata una rete per misure GPS in differenziale (DGPS) e in continuo (CGPS). Nell'ultimo decennio inoltre, l'utilizzo del radar ad apertura sintetica (SAR) su vettori satellitari ha consentito lo sviluppo e l'affinamento dell'analisi interferometrica differenziale (InSAR) e dell'analisi interferometrica su riflettori persistenti (IPTA) che si sono dimostrati di estrema efficacia per lo studio dei movimenti verticali del suolo. Nel caso della pianura costiera Veneta, sono stati utilizzati i satelliti ERS-1/2 ed ENVISAT dell'Agenzia Spaziale Europea, rispettivamente per il periodo 1992-2005 e 2003-2009, ed il satellite TerraSAR-X dell'Agenzia Spaziale Tedesca, per il biennio 2008-2009. Oggi si dispone di una densità di dati SAR che, data la risoluzione spaziale dei satelliti tra 20 e 3 m, è maggiore di circa 2 ordini di grandezza nelle l'analisi a scala regionale e più di 3 ordini per analisi locali rispetto alle misure tradizionali su capisaldi. Ciò ha permesso la mappatura dei movimenti del suolo a scala "regionale" (100×100 km2), locale (10×10 km2) e puntale al livello di singole strutture. Le serie di dati SAR sono stati calibrati e validati con le misure altimetriche di livellazione, DGPS e CGPS nella rete di monitoraggio ISES-IRMA. Grazie all'elevata densità di informazioni, all'ottima risoluzione spaziale e accuratezza verticale millimetrica del monitoraggio SAR è emersa una dinamica verticali del territorio costiero Veneto diversa da quanto ottenibile utilizzando le sole tecniche di livellazione tradizionale. L'immagine attuale indica che il processo subsidenziale si esplica con una forte variabilità spaziale, sia a scala regionale che locale. L'analisi integrata dei dati altimetrici e delle numerose nuove informazioni sul sottosuolo, recentemente acquisite nell'ambito di una serie di ricerche condotte dagli Autori, ha permesso la caratterizzazione delle componenti dei movimenti verticali del suolo della pianura costiera Veneta in funzione della profondità alla quale agiscono e la loro distribuzione areale.

Negli ultimi anni numerose ricerche di carattere geologico hanno permesso di aggiornare le conoscenze relative all'assetto ed all'evoluzione dell'area lagunare veneziana. Fondamentale importanza hanno assunto soprattutto gli studi condotti nell'ambito del Progetto di Cartografia Geologica CARG finalizzati alla realizzazione dei Fogli Geologici 128 "Venezia" e 148-149 "Chioggia-Malamocco" alla scala 1:50.000, la cui pubblicazione è avvenuta nel 2007. Queste indagini hanno permesso di definire l'età, la distribuzione, i reciproci rapporti e le caratteristiche litologiche e di facies dei sedimenti tardo-pleistocenici ed olocenici affioranti e sepolti in laguna, nell'adiacente fascia di bacino scolante e presso il litorale. I depositi individuati sono stati classificati utilizzando le Unconformity Bounded Stratigraphic Units: in particolare sono stati definiti il Supersintema di Venezia, comprensivo delle unità post-messiniane deposte a partire dal Pliocene fino alla base del Pleistocene superiore, il Supersintema di Mestre, rappresentativo dei depositi alluvionali tardo-pleistocenici, ed il Sintema del Po, costituito dai depositi olocenici e diviso in due unità, l'Unità di Malamocco e l'Unità di Torcello, distinte esclusivamente su base cronologica. Recentemente nuove ricerche, alcune delle quali tuttora in corso, hanno fornito importanti risultati che hanno permesso di aggiornare ulteriormente le conoscenze geologiche finora acquisite nel corso dei precedenti studi. In particolare, l'analisi congiunta di carotaggi e di profili ottenuti mediante un sistema di acquisizione sismica ad altissima risoluzione adatto per rilievi in bassi fondali (profondità inferiore ad 1 m) si sta rivelando particolarmente utile per migliorare la ricostruzione dell'assetto morfostratigrafico della laguna. Questo sistema ha permesso di riconoscere anche lineamenti geomorfologici finora sconosciuti sepolti in ambiente lagunare e di stabilire le relazioni tra questi ultimi ed analoghe strutture presenti nell'adiacente terraferma.

The Project "Application of innovative of very high resolution seismic methodologies in shallow waters aimed at the study of the subsoil of the Venice Lagoon" allowed the characterization of the Late Pleistocene and Holocene depositional sequences with a detail, that has never been reached in the past. A boat, particularly suitable for very high resolution seismic survey in shallow water (less than 1 m deep) has been fully equipped and tested. It allowed to carried out surveys of specific areas of the Lagoon that have never been investigated in the past. Moreover a seismo-stratigraphic model of the lagoon and gulf of Venice subsoil has been performed. The seismic acquisition system allowed to investigate the subsoil down to 30-40 m deep. The new data provided significant geological features related to the Late Pleistocene and Holocene evolution of the investigated areas: the southern lagoon, the Lido and Chioggia inlets and part of the shelf of the Gulf of Venice.

Mediante un sistema di prospezione sismica ad altissima risoluzione per rilievi su bassi fondali (meno di 1 m di profondità), integrato con l'analisi di carotaggi, è stato possibile ricostruire l'assetto stratigrafico tardo Pleistocenico ed Olocenico della Laguna di Venezia fino a -20 m s.l.m. con una risoluzione di circa 10 cm ed individuare strutture geomorfologiche sepolte e subaffioranti finora sconosciute, quali incisioni fluviali, sistemi argine-canale, paleocanali lagunari ed antichi cordoni litoranei. I risultati delle indagini hanno fornito nuovi elementi utili per capire l'evoluzione olocenica del territorio ed hanno messo chiaramente in evidenza che le diversioni fluviali indotte dall'uomo nel corso dell'ultimo millennio hanno innescato drastici cambiamenti nel regime sedimentario della laguna ed ampiamente influito sulle sue modificazioni morfologiche avvenute nel corso dei secoli.

The southernmost tip of South America is an active continental margin where oblique convergence between plates, transcurrent motion, and tectonic rotation on land make the geodynamic setting more complex than that of the central Andes. A multichannel seismic data set has been used in conjunction with multibeam and altimetry data to clarify the regional architecture of the continental margin from 50 degree S to 57 degree S. Despite the thick sedimentary section in the trench and the slow plate convergence rate peculiar of typical accretionary margins, seismic reflection profiles image widely varying frontal wedge morphologies, different rates of accretion, a high degree of structural diversity, and different modes of continental building (offscraping, underplating, tectonic erosion). Correlation between structural parameters (depth of the decollement level, width of the wedge, accretionary rates, Moho depth) suggests large-scale structural control on margin geometry and structural diversity. The transition from tectonic accretion to erosion and general structural variations do not show any gradual trend, but rather, they occur along oblique structural trends that produce a tectonic segmentation of the margin. This is mainly related to tectonic processes on the overriding plate (block rotations along strike-slip faults), while local disturbances on the incoming plate (seamounts, fracture zones, and oceanic fabric relative orientation) add further structural complexity. Altimetry data, in conjunction with structural analysis, suggest that large-scale tectonic variations and structural development are related to trench-parallel gravity anomaly variations and, ultimately, to basal friction on the plate interface. Strong negative gravity anomalies are associated with sedimentary basins, wide wedges, and accretionary domains, while positive gravity anomalies mainly refer to transverse structural highs and narrow wedges.

Most of the Venice Lagoon consists of shallows and their subsoil provides a window on the whole Holocene history while below the shipping channels the upper layers are lost because of the occurrence of bottom erosion and the dredging activity. Unfortunately, to take cores in shallows is really hard owing to impervious environment. In addition, the cores represent a very local situation due to the high facies variability of the lagoon and they need to be a significant number for the lateral correlated to reconstruct the geological setting. Very high resolution seismic survey overcomes these difficulty and data obtained provide a powerful tool to study the architecture of Holocene deposits. The near outcrop resolution provided by this technique allows the recognition of sedimentary structures and main stratal surfaces.