1,486 research outputs found
Investigating submerged morphologies by means of the low-budget âGeoDiveâ method (high resolution for detailed 3D reconstruction and related measurements)
Geophysical methods allow to collect geological data on lake and sea bottoms and characterize large areas, even at high depths, but with high costs. Moreover, the most widespread acquisition methods for morpho-bathymetric survey and the related instruments used are almost always ship-, ROV- or AUV-based and consequently they require high budgets. It is known that shallow waters can represent a limit for certain vessels and techniques, preventing the acquisition in the shoreface zone. To overcome the limits, i.e. to survey with high accuracy nearshore shallow waters with a low budget, we tested and tuned the âGeoDiveâ method that allowed us to survey two test sites, featured by the presence of âblock fieldsâ (i.e., accumulations of huge blocks and boulders of gravitational origin) under shallow waters. The âGeoDiveâ method allowed us to map the submerged morphologies and to acquire high-resolution optical images for further photogrammetric processing. The latter was fundamental to obtain 3D high-resolution models, also with conditions of low visibility. An Action Sport Cam with high definition resolution has been used for video acquisition, in addition to the equipment used during scientific diving. By coupling the processing of underwater-acquired data with the direct surveys performed by underwater SCUBA operators, it was possible to perform some morphological and sedimentological measurements and observations on the experimental targets, with the help of suitable markers
Development of a geological model useful for the study of the natural hazards in urban environments. An example from the eastern sector of Rome (Italy)
Detailed knowledge of the subsoil setting is an extremely important issue for a correct risk reduction policy, especially when dealing with urban areas hosting cultural heritage, which enhance risk conditions even at low geo-hazard levels, as in the case of Rome. In general, the reliability of risk assessments related to geo-hazards is strictly dependent on the resolution of the reference geological model. The study presented here exemplifies an integrated methodology aimed at refining the knowledge of the geological setting in unique urban environments, such as the city of Rome, where canonical approaches are limited by the scarcity of outcrops and ad-hoc geognostic surveys may be expensive and time-consuming. The methodology used in the study is based on a critical review of available geological, stratigraphic, archeological and historical-archival data. The integration of such data, properly stored, managed and analysed in a GIS environment, made it possible to: i) better frame the geological setting of a wide sector of the eastern part of Rome; and, in particular, ii) focus on buried natural morphologies (i.e. valleys) strongly modified by progressive urbanisation that determined their filling with huge thickness of backfills, which often represent a critical geotechnical issue. A detailed geological model was thus developed. The model shows slight but significant differences with respect to already available official maps, emphasising the need for carrying out in-depth analyses of already existing data from different sources, in order to collect thematic data to be used for effective land management policies
Imaging multi-age construction settlement behaviour by advanced SAR interferometry
This paper focuses on the application of Advanced Satellite Synthetic Aperture Radar Interferometry (A-DInSAR) to subsidence-related issues, with particular reference to ground settlements due to external loads. Beyond the stratigraphic setting and the geotechnical properties of the subsoil, other relevant boundary conditions strongly influence the reliability of remotely sensed data for quantitative analyses and risk mitigation purposes. Because most of the Persistent Scatterer Interferometry (PSI) measurement points (Persistent Scatterers, PSs) lie on structures and infrastructures, the foundation type and the age of a construction are key factors for a proper interpretation of the time series of ground displacements. To exemplify a methodological approach to evaluate these issues, this paper refers to an analysis carried out in the coastal/deltaic plain west of Rome (Rome and Fiumicino municipalities) affected by subsidence and related damages to structures. This region is characterized by a complex geological setting (alternation of recent deposits with low and high compressibilities) and has been subjected to different urbanisation phases starting in the late 1800s, with a strong acceleration in the last few decades. The results of A-DInSAR analyses conducted from 1992 to 2015 have been interpreted in light of high-resolution geological/geotechnical models, the age of the construction, and the types of foundations of the buildings on which the PSs are located. Collection, interpretation, and processing of geo-thematic data were fundamental to obtain high-resolution models; change detection analyses of the land cover allowed us to classify structures/infrastructures in terms of the construction period. Additional information was collected to define the types of foundations, i.e., shallow versus deep foundations. As a result, we found that only by filtering and partitioning the A-DInSAR datasets on the basis of the above-mentioned boundary conditions can the related time series be considered a proxy of the consolidation process governing the subsidence related to external loads as confirmed by a comparison with results from a physically based back analysis based on Terzaghi's theory. Therefore, if properly managed, the A-DInSAR data represents a powerful tool for capturing the evolutionary stage of the process for a single building and has potential for forecasting the behaviour of the terrain-foundation-structure combination
First insights on the potential of Sentinel-1 for landslides detection
This paper illustrates the potential of Sentinel-1 for landslide detection, Accepted 23 March 2016 mapping and characterization with the aim of updating inventory maps and monitoring landslide activity. The study area is located in Molise, one of the smallest regions of Italy, where landslide processes are frequent. The results achieved by integrating Differential Synthetic Aperture Radar Interferometry (DInSAR) deformation maps and time series, and Geographical Information System (GIS) multilayer analysis (optical, geological, geomorphological, etc.) are shown. The adopted methodology is described followed by an analysis of future perspectives. Sixty-two landslides have been detected, thus allowing the updating of pre-existing landslide inventory maps. The results of our ongoing research show that Sentinel-1 might represent a signiïŹcant improvement in terms of exploitation of SAR data for landslide mapping and monitoring due to both the shorter revisit time (up to 6 days in the close future) and the wavelength used, which determine an higher coherence compared to other SAR sensors
Geological constraints for a conceptual evolutionary model of the slope deformations affecting Mt. Nuovo at Ischia (Italy)
ischia island was the scenario of several Holocene slope in- stability events occurred at different scales, from shallow mass movements, triggered by meteo-climatic forcing, up to massive rock slope failures such as large debris avalanches these last ones related to the volcano-tectonic dynamics of a resurgent caldera. the present study focuses on the gravitational deformation that in- volves Mt. nuovo, located in the western portion of Mt. epomeo resurgent block. a high-resolution engineering-geological model was reconstructed according to a multi-modelling approach sup- ported by field geo-structural evidences and constrained by pas- sive seismic investigations. it revealed a complex morpho-struc- tural setting and led to the identification of a multiple compound mechanism, involving a rock mass volume of about 190 million of cubic meters.
the obtained geological model shows a partial structural control of the pre-existing tectonic pattern on slope deformation mechanisms, highlighting geometric and volumetric similarities between the Mt. nuovo ongoing deformation and an already oc- curred rock avalanche. the defined conceptual evolutionary mod- el allows to hypothesize the role of inner pressures constraining the shear zone initiation and propagation and making reliable a future scenario of generalized collapse.
Starting from these new field and laboratory data, numerical models will be reconstructed in order to depict the evolution of the gravitational slope deformation, evaluate its sensitivity and constrain future evolutionary instability scenarios
Hydrogeochemical model supporting the remediation strategy of a highly contaminated industrial site
Delineation and understanding the geology and the hydrogeology of a contaminated site, considering its chemical and its biological aspects, are fundamental requirements for successful environmental remediation. The aim of this research is to provide some evidence about the effectiveness of a hydrogeochemical geodatabase to facilitate the integrated management, representation and analysis of heterogeneous data, enabling the appropriate selection, design and
optimization of an effective remediation strategy. This study investigates a new technology for the remediation of a dense non-aqueous phase liquid aged source zone, with the aim of enhancing in situ bioremediation by coupling groundwater circulation wells with a continuous production system of electron donors. The technology was verified through a pilot test carried out at an industrial site highly contaminated by chlorinated aliphatic hydrocarbons. The multidisciplinary conceptual model confirmed a complex hydrogeological situation, with the occurrence of active residual sources in low permeability layers. The pilot test results clearly demonstrate a significant mobilization of contaminants from the low permeability zone, and the possibility of favoring the in situ natural attenuation mechanisms based upon biological reductive dechlorination. Different information related to the hydrogeochemical sphere must be integrated and taken into consideration when developing a reliable remediation strategy for contaminated sites
Earthquakeâinduced landslide scenarios for seismic microzonation. Application to the Accumoli area (Rieti, Italy)
Scenarios of earthquake-induced landslides are necessary for seismic microzonation (SM) studies since they must be integrated with the mapping of instability areas. The PARSIFAL (Probabilistic Approach to pRovide Scenarios of earthquakeâInduced slope FAiLures) approach provides extensive analyses, over tens to thousands of square kilometers, and is designed as a fully comprehensive methodology to output expected scenarios which depend on seismic input and saturation conditions. This allows to attribute a rating, in terms of severity level, to the landslide-prone slope areas in view of future engineering studies and designs. PARSIFAL takes into account first-time rock- and earth-slides as well as re-activations of existing landslides performing slope stability analyses of different failure mechanisms. The results consist of mapping earthquake-induced landslide scenarios in terms of exceedance probability of critical threshold values of co-seismic displacements (P[Dâ„Dc|a(t),ay]). PARSIFAL was applied in the framework of level 3 SM studies over the municipality area of Accumoli (Rieti, Italy), strongly struck by the 2016 seismic sequence of Central Apennines. The use of the PARSIFAL was tested for the first time to screen the Susceptibility Zones (ZSFR) from the Attention Zones (ZAFR) in the category of the unstable areas, according to the guidelines by Italian Civil Protection. The results obtained were in a GIS-based mapping representing the possibility for a landslide to be induced by an earthquake (with a return period of 475 years) in three different saturation scenarios (i.e. dry, average, full). Only 41% of the landslide-prone areas in the Municipality of Accumoli are existing events, while the remaining 59% is characterized by first-time earth- or rock-slides. In dry conditions, unstable conditions or P[Dâ„Dc|a(t),ay]>0 were for 54% of existing landslides, 17% of first-time rock-slides and 1% of first-time earth- slides. In full saturation conditions, the findings are much more severe since unstable conditions or P[Dâ„Dc|a(t),ay]>0 were found for 58% of the existing landslides and for more than 80% of first-time rock- and earth-slides. Moreover, comparison of the total area of the ZAFR versus ZSFR, resulted in PARSIFAL screening reducing of 22% of the mapped ZAFR
Therapeutic potential of the phosphino Cu(I) complex (HydroCuP) in the treatment of solid tumors
[Cu(thp)4][PF6] (HydroCuP) is a phosphino copper(I) complex highly soluble and stable in physiological media that has been developed as a possible viable alternative to platinum-based drugs for anticancer therapy. HydroCuP potently inhibited the growth of human cancer cells derived from solid tumors by inducing endoplasmatic reticulum (ER) stress thus leading to cell death through paraptosis with a preferential efficacy against cancer rather than non-cancer cells. Aim of the present study was to assess the therapeutic potential of HydroCuP in vivo, in syngenic and xenograft murine models of solid tumors by triggering the Unfolded Protein Response (UPR) pathway. With respect to platinum drugs, HydroCuP induced a markedly higher reduction of tumor growth associated with minimal animal toxicity. In human colorectal cancer xenografts, chemotherapy with HydroCuP was extremely effective in both oxaliplatin-sensitive and resistant models. The favorable in vivo tolerability of HydroCuP was also correlated to an encouraging biodistribution profile. Additionally, no signs of drug-related neurotoxicity and nephrotoxicity were observed. Altogether, these results demonstrate that HydroCuP appears worth of further investigation to evaluate its therapeutic activity towards a broad spectrum of solid malignancies
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