INDAGINI NON INVASIVE SU ALCUNE COLONNE DELLA VILLA ROMANA DEL CASALE, A PIAZZA ARMERINA

Alcune indagini non invasive sono state eseguite a supporto delle prove di verifica delle colonne prospicienti il Corridoio della Grande Caccia della Villa Romana del Casale, a Piazza Armerina. Scopo del progetto di indagine è la localizzazione di eventuali perni metallici e anomalie interne nelle dieci colonne che separano il Corridoio della Grande Caccia dal Peristilio e valutare il livello di portanza delle singole colonne. A tale scopo sono state eseguite indagini georadar e soniche. Le indagini georadar sono state effettuate utilizzando un apparecchiatura munita di antenna con frequenza centrale di 1000 MHz in modalità monostatica, per ogni colonna, sono stati acquisiti 4 profili verticali nel fusto, speculari a due a due, e due profili orizzontali: uno base del capitello e l’altro alla base del capitello. Operando con apparecchiatura sonica con sonde di 20 kHz, sono state effettuate circa un centinaio di acquisizione, allo scopo di ricostruire, per ciascuna colonna, un diagramma di distribuzione delle velocità sonica (Tomografia) e indagare sull’integrità del materiale costituente

A Fast Imaging Technique Applied to 2D Electrical Resistivity Data

A new technique is proposed to process 2D apparent resistivity datasets, in order to obtain a fast and contrasted resistivity image, useful for a rapid data check in field or as a starting model to constrain the inversion procedure. In the past some modifications to the back-projection algorithm, as well as the use of filtering techniques for the sensitivity matrix were proposed. An implementation of this technique is proposed here, considering a two-step approach. Initially a damped least squares solution is obtained after a full matrix inversion of the linearized geoelectrical problem. Furthermore, on the basis of the results, a subsequent filtering algorithm is applied to the Jacobian matrix, aiming at reducing smoothness, and the linearized damped least square inversion is repeated to get the final result. This fast imaging technique aims at increasing the resistivity contrasts and practically, since it does not require a parameter set optimization, it can be used to easily obtain fast and preliminary results. The proposed technique is tested on synthetic data, the objective of which is to find the optimal parameter set. Finally, two field cases are discussed and the comparison between back-projection and inversion is shown

Electromagnetic and ultrasonic investigations on a Roman marble slab

The archaeological museum of Rome asked our group about the physical consistency of a marble slab (second to third century AD) that recently fell during its travel as part of an exhibition. We decided to use different methodologies to investigate the slab: namely a pacometer (Protovale Elcometer) to individuate the internal coupling pins, and ground-penetrating radar (GPR) (2000 MHz) and ultrasonic (55 kHz) tomographic high-density surveys to investigate the internal extension of all the visible fractures and to search for the hidden ones. For the ultrasonic data, tests were carried out to optimize the inversion parameters, in particular the cell dimensions. The choice of cell size for the inversion process must take into account the size of the acquisition grid and the ray number acquired. We proposed to calculate a minimum Fresnel’s radius using the sampling frequency instead of that of the probes. For every methodology used, the quality of the acquired data was relatively high. This was then processed and compared to provide information that was useful for some of the insurance problems of the museum. Later on, the data was processed in depth to see how to improve the data processing and interpretation. Finally, the results of this in-depth study were exposed in detail. Ultrasonic and GPR tomographies show a strong correlation, and in particular, the inhomogeneous areas are located in correspondence to the slab injuries

Some tests of 3D ultrasonic traveltime tomography on the Eleonora d'Aragona statue (F. Laurana, 1468)

The use of a non-destructive technique in situ can be a valuable diagnostic tool to support verification of restoration, as well as a monitoring technique in works of art or historical monuments. We present a high resolution 3D ultrasonic tomography to one of the most important statues of the Regional Gallery of Palazzo Abatellis of Palermo, the bust of Eleonora d'Aragona by F. Laurana (1430–1502). This technique allowed to study the structural continuity of the material of the marble. Some tests have been carried out to optimize inversion parameters, such as voxel size and to choose between straight and curved rays. We propose to calculate a minimum lateral resolution using the sampling frequency instead of that of the probes. Consequently it was chosen to use a voxel size of 2 cm, lower than the expected resolution, 0.07 m (calculated considering the median ray length), and also to use curved rays instead of straight rays approximation. The resulting model showed velocity values corresponding to a sufficiently homogeneous and well-preserved marble, but in the lower front portion of the trunk at the breasts, that bears the entire weight of the artwork, low velocity values are present

Virtual three-dimensional model of the subsoil of the church of St. Maria Maddalena d'Alga in Palermo, using high-resolution GPR surveys

The church of Santa Maria Maddalena d'Alga is located in the historic center of Palermo and belongs to the monumental complex of the military district of San Giacomo, in the ancient western fortified area of the city. Today the area hosts a vast military complex, seat of the Command of the Carabinieri Legion of Sicily. The church is elevated with respect to the current floor. During some maintenance works of the church, for the installation of air conditioners, some georadar surveys were carried out to verify the presence of crypts or tombs under the pavement. The investigations made it possible to reconstruct a 3D georadar model and to identify some anomalies under the pavement. Some of these correspond to rooms that have been opened during maintenance work

TECNICHE NON INVASIVE DI SUPERFICIE E DI VOLUME PER IL MONITORAGGIO STRUTTURALE DELLE SCULTURE MARMOREE

L’analisi delle proprietà strutturali di una scultura in marmo, attraverso l’impiego di tecniche di indagine non invasive da realizzare direttamente in situ, è di fondamentale importanza per la valutazione dello stato di conservazione e, conseguentemente, per il monitoraggio di eventuali fenomeni di degrado che possono compromettere l’integrità dell’opera d’arte. Lo studio condotto sul bassorilievo raffigurante la Madonna con Bambino conservato presso la Cappella del Monastero delle Clarisse Totus Tuus di Gorizia ha permesso di verificare la complementarietà delle informazioni restituite da tecniche di analisi della superficie (acquisizioni in fluorescenza ultravioletta) e tecniche di analisi del volume (tomografia ultrasonica). Le indagini in fluorescenza ultravioletta consentono di individuare e differenziare i materiali (originali, di restauro o di degrado) presenti sulla superficie lapidea. La tomografia ultrasonica, attraverso la stima delle velocità ultrasoniche caratteristiche del materiale, permette di ottenere una caratterizzazione strutturale dell’intero volume dell’opera. Generalmente, tale indagine è associata a un rilievo pacometrico necessario per rilevare la presenza di perni metallici all'interno dell'opera o nel supporto di ancoraggio, anche per interpretare eventuali anomalia riscontrate. Nel caso studio presentato, il modello tomografico ad ultrasuoni ha evidenziato la presenza di piccole zone ad alta velocità correlabili alla presenza di perni metallici e da una zona a maggiore degrado che si concentra nella parte inferiore dell’opera. Le indagini in fluorescenza ultravioletta hanno mostrato la reale estensione della frattura che coinvolge la porzione inferiore del bassorilievo, verificando il perimetro dell’area caratterizzata da un maggior degrado ed evidenziata dall’indagine ad ultrasuoni

MAPPING LOCAL CLIMATE ZONES WITH MULTIPLE GEODATA AND THE OPEN DATA CUBE: INSIGHTS OF DOMAIN USER REQUIREMENTS AND OUTLOOKS OF THE LCZ-ODC PROJECT

Rapid urbanization and climate change are intensifying the urban heat island (UHI) phenomenon across cities worldwide. There is a pressing need to implement evidence-based mitigation and adaptation strategies as well as to develop tools for effectively measuring the impact of such actions on UHI patterns. In this context, the Local Climate Zone (LCZ) concept is a well-established classification system commonly used for the assessment of UHI. With this in mind, we present here the LCZ-ODC project aiming to develop a methodology for LCZ mapping in the Metropolitan City of Milan (northern Italy) by leveraging multiple geospatial data and cutting-edge software tools, including the Open Data Cube (ODC). A key aim of the project is to develop user-oriented solutions facilitating the exploitation of the generated LCZ maps for different application tasks. In this paper, we first present a brief overview of the methodologies and data sources used in the literature for LCZ mapping. Then, we introduce the LCZ-ODC project, with a focus on the end-user requirements which were gathered through a questionnaire distributed to a sample of potential stakeholders. The primary objective of the survey was to collect insights and consolidate requirements related to the key features of LCZ maps that will be produced within the project. The outcomes of the survey play a pivotal role in guiding the project’s development phase, ensuring that the project outputs will effectively address the identified end-user needs

"Dietaly": Practical issues for the nutritional management of CKD patients in Italy

Evidence exists that nutritional therapy induces favorable metabolic changes, prevents signs and symptoms of renal insufficiency, and is able to delay the need of dialysis. Currently, the main concern of the renal diets has turned from the efficacy to the feasibility in the daily clinical practice. Herewith we describe some different dietary approaches, developed in Italy in the last decades and applied in the actual clinical practice for the nutritional management of CKD patients. A step-wise approach or simplified dietary regimens are usually prescribed while taking into account not only the residual renal function and progression rate but also socio-economic, psychological and functional aspects. The application of the principles of the Mediterranean diet that covers the recommended daily allowances for nutrients and protein (0.8 g/Kg/day) exert a favorable effect at least in the early stages of CKD. Low protein (0.6 g/kg/day) regimens that include vegan diet and very low-protein (0.3-0.4 g/Kg/day) diet supplemented with essential amino acids and ketoacids, represent more opportunities that should be tailored on the single patient’s needs. Rather than a structured dietary plan, a list of basic recommendations to improve compliance with a low-sodium diet in CKD may allow patients to reach the desired salt target in the daily eating. Another approach consists of low protein diets as part of an integrated menu, in which patients can choose the “diet” that best suits their preferences and clinical needs. Lastly, in order to allow efficacy and safety, the importance of monitoring and follow up of a proper nutritional treatment in CKD patients is emphasized

Integration of HVSR measures and stratigraphic constraints for seismic microzonation studies: the case of Oliveri (ME)

Because of its high seismic hazard the urban area of Oliveri has been subject of first level seismic microzonation. The town develops on a large coastal plain made of mixed fluvial/marine sediments, overlapping a complexly deformed substrate. In order to identify points on the area probably suffering relevant site effects and define a preliminary Vs subsurface model for the first level of microzonation, we performed 23 HVSR measurements. A clustering technique of continuous signals has been used to optimize the calculation of the HVSR curves. 42 reliable peaks of the H/V spectra in the frequency range 0.6–10 Hz have been identified. A second clustering technique has been applied to the set of 42 vectors, containing Cartesian coordinates, central frequency and amplitude of each peak to identify subsets which can be attributed to continuous spatial phenomena. The algorithm has identified three main clusters that cover significant parts of the territory of Oliveri. The HVSR data inversion has been constrained by stratigraphic data of a borehole. To map the trend of the roof of the seismic bedrock, from the complete set of model parameters only the depth of the seismic interface that generates peaks fitting those belonging to two clusters characterized by lower frequency has been extracted