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Artificial Intelligence for Spatiotemporal Data and Remote Sensing Applications in Monitoring Systems
No full textI moderni sistemi di monitoraggio si basano su vaste e ubiquitarie reti di sensori che registrano dati provenienti da processi fisici, con applicazioni nei settori marittimo, agricolo, dell’ispezione delle infrastrutture pubbliche e in molti altri ambiti di gestione. Questi sistemi generano grandi quantità di dati temporali, spaziotemporali e visivi, che vengono analizzati per ridurre il carico di lavoro e i ritardi operativi causati dalle attività manuali. I sistemi di monitoraggio supportano enti regolatori e autorità nella conservazione delle risorse, nella valutazione della conformità, nell’analisi dei rischi e nel supporto decisionale di routine. Tuttavia, la loro efficacia è soggetta a fattori operativi, ad esempio limitazioni dovute a guasti dei sensori, connettività instabile in ambienti difficili, interferenze meteorologiche e disattivazione intenzionale dei dispositivi di trasmissione, tra gli altri, che generano lacune in informazioni critiche. Questa tesi affronta sfide di monitoraggio e gestione in tre domini applicativi e mira a rispondere ai seguenti quesiti di ricerca: (i) come ottenere o ricostruire dati spaziotemporali quando la sensorizzazione è incompleta, (ii) come rilevare e caratterizzare oggetti piccoli o visivamente poco distintivi in presenza di dati e risorse limitati, e (iii) come associare modalità eterogenee di dati in contesti in cui copertura e qualità variano. Il primo dominio è il monitoraggio marittimo, in cui il lavoro esamina come ricostruire con sufficiente accuratezza segmenti mancanti nelle traiettorie delle imbarcazioni al fine di supportare decisioni operative. Viene introdotto un modello ricorrente BF-BiLSTM che combina dati spaziotemporali forward e backward in una rappresentazione condivisa, migliorando le prestazioni di ricostruzione sia su lacune brevi sia su intervalli estesi generati da malfunzionamenti nei sistemi di segnalazione o da disattivazioni deliberate dei trasponder AIS. Questo studio esamina inoltre come rilevare piccole imbarcazioni in presenza di dati annotati limitati e risorse computazionali vincolate in ambienti marittimi complessi. A tal fine vengono analizzati diversi rilevatori convoluzionali con architetture e dimensioni differenti e vengono applicate ottimizzazioni che migliorano il rilevamento di bersagli di piccole dimensioni nelle immagini satellitari e, inoltre, la classificazione di pescatori ricreativi a partire dalle immagini. Inoltre, viene proposta una pipeline multimodale che allinea dati spaziotemporali AIS con rilevamenti provenienti da sensori di imaging satellitare multipli al fine di identificare comportamenti cooperativi e non cooperativi delle piccole imbarcazioni. Il secondo dominio è la telemetria agricola e ambientale, in cui la tesi studia come migliorare registrazioni di posizione GNSS frammentate quando la disponibilità di rete diminuisce e mostra come una configurazione dedicata di raccolta e ingestione dei dati riduca le incoerenze di posizione e fornisca traiettorie stabili per analisi successive quali la conservazione delle risorse minimizzando le aree sovrapposte nelle operazioni. Oltre ai dati di posizionamento, il lavoro si estende alle serie temporali ambientali multivariate attraverso uno studio sul monitoraggio delle acque sotterranee, nel quale modelli previsionali classici e neurali vengono confrontati per valutarne la capacità di rappresentare la dinamica stagionale della ricarica. Questo studio mostra che le dinamiche di breve periodo delle acque sotterranee possono essere previste in modo affidabile anche con osservazioni limitate quando variabili ambientali multivariate vengono incorporate come regressori esterni e quando viene adottata una strategia appropriata di validazione incrociata per stabilizzare l’addestramento del modello in condizioni di scarsità di dati. Il terzo dominio è l’ispezione delle infrastrutture pubbliche, in cui il lavoro si concentra sulle attività di monitoraggio legate al problema della scarsità di immagini di difetti. Viene proposto un framework di inpainting controllabile COIGAN che genera classi di difetti valutate empiricamente e migliora le applicazioni successive, testate tramite modelli di segmentazione, dimostrando miglioramenti quando addestrati su immagini generate. Nel complesso, i contributi dimostrano che anche quando la sensorizzazione è irregolare o incompleta è possibile supportare decisioni operative robuste attraverso la progettazione di metodi espliciti. Questi risultati mostrano come sia comunque possibile costruire modelli robusti basati sui dati in condizioni operative reali.Modern monitoring systems depend on vast and ubiquitous sensor networks that record data from physical processes, with applications in maritime, agricultural, public infrastructure inspection, and many other domains for management purposes. These systems generate large amount of time series, spatiotemporal and visual data, which are analysed to reduce workload and operational delays caused by manual operations. Monitoring systems help regulatory bodies and authorities with resource conservation, compliance assessment, risk evaluation, and routine decision support. However, their effectiveness is subject to operational factors, for instance, limitations arising due to sensor failures, unstable connectivity in challenging environments, weather interference, and intentional disabling of reporting devices among many others, that create gaps in critical information. This thesis addresses some monitoring and management challenges, across three application domains and aims to answer the following research questions, (i) how to obtain or reconstruct spatiotemporal data when sensing is incomplete, (ii) how to detect and characterize small or visually scarce objects under limited data and resource constraints, and (iii) how to associate heterogeneous data modalities in settings where data coverage and quality vary. The first domain is maritime monitoring, where the work examines how missing segments in vessel trajectories can be reconstructed with sufficient accuracy to support operational decisions. A recurrent model BF-BiLSTM is introduced that combines backward and forward spatiotemporal data in a shared representation, which improves reconstruction performance across both short and extended gaps created by reporting failures or deliberate deactivation of the AIS transponders. This study also examines how small maritime vessels can be detected under limited annotated data and constrained computational resources in challenging maritime environments. To this end a range of convolutional object detectors with varying model architecture and sizes are examined and optimizations are performed that improve detection of small targets in satellite imagery and additionally classification of recreational fishers from imagery. Additionally, a multimodal pipeline is proposed that aligns spatiotemporal AIS data with detections from multiple satellite based imaging sensors in order to identify cooperative and non-cooperative behaviour from small vessels. The second domain is agricultural and environmental telemetry, where this thesis investigates how fragmented GNSS location records can be improved when network availability drops, and shows how a dedicated data collection and ingestion setup reduces positional inconsistencies and provides stable trajectories for downstream analyses such as resource conservation minimizing overlapping area in operations. Beyond positioning data, the work extends to multivariate environmental time series through a groundwater-monitoring study, in which both classical and neural forecasting models are compared to assess their ability to represent seasonal recharge dynamics. This study shows that short term groundwater dynamics can be forecasted reliably even with limited data when multivariate environmental variables are incorporated as external regressors and an appropriate cross validation strategy is used to stabilise model training under data scarcity. The third domain is public infrastructure inspection, where this work focuses on the monitoring activities concerned with the problem of scarcity of defect imagery. A controllable inpainting framework COIGAN is proposed that generates empirically evaluated defect classes and improves downstream applications tested through segmentation models demonstrating improvements when trained on generated images. Taken together, the contributions demonstrate that even when sensing is irregular or incomplete it is possible to support robust operational decisions by design of explicit methods. These results show how robust data driven models can still be built under real world conditions
Magnetism of nanostructured hematite: from cultural heritage to fundamental properties
Full text linkThis study presents a comprehensive magnetic and morpho-structural investigation of α-Fe2O3 nanostructures from two distinct origins: natural (geologically extracted) and synthesized (i.e., laboratory-synthesized by an auto-combustion sol–gel method and commercially purchased hematite). All samples underwent thermal treatments, designed to reproduce color changes typical of hematite pigments in archaeological contexts. Through a combination of DC magnetization measurements and Mössbauer spectroscopy, we demonstrated the possibility of differentiating the origin of hematite nanostructures based on their magnetic behavior. Interestingly, low-temperature NPD analysis revealed that the intensity of the magnetic peak (003) was partially suppressed but not completely extinguished as expected for a perfect antiferromagnetic alignment, which suggests a possible coexistence of weakly ferromagnetic and antiferromagnetic phases in distinct domains below the Morin transition
Integrated Multilayer Reinforcement Model: Explaining the Dynamics of Online Radicalization
Full text linkOnline social platforms have become a fertile ground for the rapid spread of extremist narratives, yet traditional single-layer network analyses overlook the interplay of content, timing, and polarization that fuels radicalization. We introduce the Integrated Multilayer Reinforcement Model (IMRM), a unified framework that represents each user as a node in four interdependent layers (interaction, content similarity, temporal dynamics, and sentiment) and explicitly encodes feedback loops via uniform interlayer coupling. We define three novel measures: Composite Reinforced Centrality (CRC), which multiplicatively aggregates a user's normalized influence across layers; Temporal Burst Influence (TBI), which captures episodic surges in activity; and Sentiment Synchronization Coefficient (SSC), which quantifies emotional alignment with peers. We derive four theoretical propositions linking these measures to radicalization processes and validate them on Reddit data surrounding five major United States socio-political events. Our experiments reveal that (i) high CRC users have a high probability of being radicalized, (ii) radicalized users have higher values of both TBI and SSC, (iii) bridging nodes linking different communities exhibit elevated CRC, and (iv)CRC remains a robust, context-invariant predictor of radical engagement. The findings aim at highlighting how online radicalization emerges from the synergistic fusion of who you interact with, what you share, when you act, and how you feel
A Surgeons-Only Transcatheter Aortic Valve Implantation Programme: What Did We Learn After 1000 Procedures
No full textInvestigating the Semi-Permeable Membrane Behavior of Geosynthetic Clay Liners by Means of a Novel Apparatus
Full text linkThe paper presents a recently developed rigid-wall diffusion cell and the experimental setup that allows the determination of the coefficient omega, which quantifies the degree of solute restriction in clays or GCLs that exhibit semi-permeable membrane behaviour. In addition, the apparatus allows the monitoring of the total vertical stress acting on the specimen during a chemico-osmotic diffusion test while keeping the vertical deformations at a negligible level (<1%). This improvement of the traditional testing approach allows for the determination of the chemical-osmotic efficiency coefficient, omega, and of the swelling coefficient omega, the main parameters that characterize the chemico-osmotic behaviour of clays and GCLs on the same specimen. The paper also reports on the results of some tests carried out on conventional and enhanced GCLs, with the main purpose of comparing the results obtained by means of the new testing apparatus with literature data. A first application of an advanced existing theoretical model for the description of chemical-osmotic phenomena to the results obtained is also illustrated
Shaken up or still studying? Student performance after the Central Italy earthquake
Full text linkNatural hazards and disasters have diverse impacts on populations worldwide in different ways, including significant effects on students and educational systems. While the effects of COVID-19 on students have been extensively explored, less attention has been given to the impacts of disasters at the NUTS (nomenclature of territorial units for statistics)-3 level, particularly in Western European countries. This study investigates the effects of the 2016 Central Italy earthquake on the learning outcomes of primary school students using standardised test scores at the NUTS-3 level provided by INVALSI (Istituto Nazionale per la Valutazione del Sistema Educativo di Istruzione e di Formazione). Using a quasi-experimental design, we analyse the data through a dual methodological approach that combines synthetic difference-indifferences (SDID) and event study methodologies. The findings reveal a significant negative impact of the earthquake on the test scores of second-year primary school students, while effects on fifth-year students are not statistically significant. Notably, the negative impact persists for approximately two years, highlighting the enduring educational consequences of disasters. This case study offers policy implications for educational systems in the aftermath of an earthquake, as well as a quantitative background for comparative research on education in Europ
Hyaluronic acid and sodium cromoglycate (J.O.I.N.T project): Analysis of Inflammatory Cytokine Production Using a Co-Culture Model of Chondrocytes and Mast Cells
No full textOsteoarthritis (OA) has long been considered a “non-inflammatory” form of arthritis. However, recent immunohistochemical studies have demonstrated the presence of inflammatory infiltrates and, notably, mast cells within the synovial membrane of osteoarthritic joints. Given the crucial role of these elements in the pathogenesis and progression of OA, there is growing interest in synovial mast cells and, consequently, in drugs capable of inhibiting them, such as sodium cromoglycate. Intra-articular injections of hyaluronic acid are widely used in OA management, providing symptom relief and improving patients’ quality of life. Nevertheless, their effect is time-limited and highly variable, prompting the development of combined formulations to enhance efficacy. Following promising in vitro results with cromones for mast cell inhibition, we patented a novel compound combining the beneficial properties of hyaluronic acid and sodium cromoglycate. Mast cells play a key role in OA pathogenesis and in the production of cytokines involved in pain transmission (e.g., NGF). Therefore, this formulation represents a treatment capable of addressing both OA symptoms and underlying pathogenic mechanisms. These features highlight its potential as an innovative therapy with significant clinical applications, considering the global prevalence of OA as a true pandemic. Moreover, the development of a solution combining hyaluronic acid and sodium cromoglycate constitutes an absolute novelty in the pharmaceutical landscape.
Unveiling the toxic effects of perfluorooctanoic acid on osteoblast function and extracellular matrix deposition using 2D and 3D models
No full textEmerging evidence revealed an association between perfluorooctanoic acid (PFOA) exposure and reduced bone mass density, leading to osteoporosis disease. This confirms the bone as a target tissue for per- and polyfluoroalkyl substances (PFAS). However, it is still unclear during which phase, proliferation or differentiation, PFOA exerts the most significant harm on osteoblasts, the cells responsible for secreting bone matrix. To tackle the intriguing question of how PFOA treatment affects the process, this study investigated the impact of different concentrations of PFOA on 2D and 3D human fetal osteoblast (hFOB1.19) cell line cultures representing the proliferation and differentiation phases, respectively. In 2D cultures, a 6-day PFOA exposure impaired antioxidant defense without directly altering osteogenesis or calcium deposition. In 3D spheroids, PFOA disrupted spheroid morphology and the deposition of the organic component of extracellular matrix (ECM) in a time-dependent manner. Given the relevance of the endocannabinoid system (ECS) in bone remodeling, we further assessed cannabinoid receptor 1 (CB1) levels. In 2D cultures, 10 μM PFOA reduced CB1 protein levels in parallel with decreased collagen levels. Conversely, in 3D spheroids, exposure to 100 μM PFOA for 2 days significantly increased CB1 levels while reducing the levels of degraded collagen. These findings emphasize the non-monotonic, phase- and time-dependent effects of PFOA on osteoblast function and ECM deposition, underscoring the need for further research into its long-term impact on bone homeostasis and human health induced by this emerging concern contaminant. (Figure presented.
Micro and Macrovascular disease in Systemic Sclerosis: An Observational Prospective Cohort Study
No full textIntroduzione. La sclerosi sistemica (SSc) è una malattia del tessuto connettivo caratterizzata da disfunzione endoteliale, vasculopatia micro- e macrovascolare e fibrosi. Dati recenti supportano il modello di “unified vascular framework”, in cui il danno vascolare rappresenta l’evento patogenetico centrale e comune ai diversi distretti circolatori. Tuttavia, mancano studi clinici che valutino in modo integrato microcircolo, macrocircolo e biomarcatori endoteliali lungo lo spettro PRP–VEDOSS–SSc.
Obiettivi. Scopo di questo studio osservazionale prospettico è stato caratterizzare in maniera multidimensionale la compromissione vascolare nei pazienti con SSc conclamata e VEDOSS rispetto a soggetti con fenomeno di Raynaud primario (PRP), esplorando le relazioni tra danno microvascolare, alterazioni macrovascolari e biomarcatori circolanti di disfunzione/danno endoteliale.
Metodi. Sono stati arruolati 62 soggetti adulti: 34 con SSc (21 lcSSc, 13 dcSSc), 14 VEDOSS e 14 PRP. Tutti i partecipanti sono stati sottoposti a valutazione clinica, stima del rischio cardiovascolare (SCORE2/SCORE2-OP), capillaroscopia periungueale, studio della funzione endoteliale mediante flow-mediated dilation (FMD) dell’arteria brachiale, ecocolorDoppler arterioso multisegmentario (distretti carotideo-vertebrale, aortico e arti inferiori) con calcolo di IMT, ABI e RRI, ed ecocardiografia standard. A livello laboratoristico sono stati dosati von Willebrand factor, ICAM-1, VCAM-1 e conteggiate le circulating endothelial cells (CECs). Le analisi statistiche hanno utilizzato test parametrici e non parametrici, chi-quadrato e correlazioni di Spearman, con p≤0,05 considerato significativo.
Risultati. La malattia microvascolare ha mostrato una progressione significativa dal PRP al VEDOSS fino alla SSc, sia in termini di pattern capillaroscopico sia di storia di ulcere digitali, confermando il microcircolo quale primo distretto coinvolto. Le alterazioni macrovascolari (placche, stenosi, occlusioni, aneurismi) erano più frequenti in SSc (52,9%) e VEDOSS (50,0%) rispetto al PRP (21,4%), delineando un possibile continuum di coinvolgimento macrovascolare già nelle fasi precoci, pur in assenza di significatività statistica. Né SCORE2 né l’IMT carotideo differivano significativamente tra i gruppi, suggerendo che gli strumenti convenzionali non colgono l’eccesso di rischio vascolare nella SSc. I livelli di VCAM-1 risultavano significativamente più elevati nei pazienti con SSc rispetto a VEDOSS e PRP, mentre ICAM-1 e CECs erano aumentati nella SSc rispetto ai controlli, indicando un gradiente di attivazione e danno endoteliale lungo lo spettro di malattia. Non sono state osservate differenze significative nelle citochine circolanti tra PRP e VEDOSS, suggerendo che i meccanismi di attivazione endoteliale non siano ancora pienamente attivati nelle fasi molto precoci. Nei soggetti con evidenza di aterosclerosi ecografica la FMD era più ridotta e i livelli di VCAM-1 più elevati rispetto ai pazienti senza aterosclerosi, a sostegno di una disfunzione endoteliale sistemica che integra micro- e macroangiopatia.
Conclusioni. I risultati di questo studio sono coerenti con il paradigma dell’“unified vascular framework”, in cui la SSc si configura come una malattia vascolare sistemica a partenza endoteliale, caratterizzata da un continuum di danno micro- e macrovascolare già nelle fasi precoci (VEDOSS). La dissociazione tra rischio cardiovascolare stimato e burden vascolare reale sottolinea la necessità di sviluppare score predittivi specifici per la SSc che includano biomarcatori endoteliali quali VCAM-1, ICAM-1 e CECs. Questi marker, insieme agli indici strumentali di danno vascolare, potrebbero contribuire a identificare fenotipi ad alto rischio e a guidare strategie terapeutiche precoci mirate alla protezione endoteliale. Abbiamo riscontrato un maggiore burden aterosclerotico che coinvolge in maniera analoga VEDOSS e SSc, implicando un danno macrovascolare precoce nel decorso della malattia. Tuttavia, tale processo aterogenico iniziale sembra essere indipendente dalla disfunzione endoteliale, poiché l’incremento dei marker di attivazione endoteliale e delle cellule endoteliali circolanti diventa significativo solo nelle fasi più avanzate. Studi multicentrici con campioni più ampi e follow-up longitudinale sono necessari per confermare e validare tali evidenze.Introduction. Systemic sclerosis (SSc) is a connective tissue disease characterized by endothelial dysfunction, micro- and macrovascular vasculopathy, and fibrosis. Recent data support the “unified vascular framework” model, in which vascular damage represents the central pathogenic event shared across different circulatory districts. However, clinical studies that comprehensively assess microcirculation, macrocirculation, and endothelial biomarkers across the PRP–VEDOSS–SSc spectrum are lacking.
Objectives. The aim of this prospective observational study was to multidimensionally characterize vascular impairment in patients with established SSc and VEDOSS compared with individuals with primary Raynaud’s phenomenon (PRP), exploring the relationships between microvascular damage, macrovascular alterations, and circulating endothelial dysfunction/damage biomarkers.
Methods. A total of 62 adult subjects were enrolled: 34 with SSc (21 lcSSc, 13 dcSSc), 14 VEDOSS, and 14 PRP. All participants underwent clinical evaluation; cardiovascular risk assessment (SCORE2/SCORE2-OP); nailfold videocapillaroscopy; endothelial function assessment via brachial artery flow-mediated dilation (FMD); multisegmental arterial duplex ultrasound (carotid-vertebral, aortic, and lower limb districts) including IMT, ABI, and RRI calculation; and standard echocardiography. Laboratory analyses included von Willebrand factor, ICAM-1, VCAM-1 quantification, and circulating endothelial cell (CEC) enumeration. Statistical analyses included parametric and non-parametric tests, chi-square test, and Spearman correlations; p≤0.05 was considered statistically significant.
Results. Microvascular disease exhibited a significant progression from PRP to VEDOSS to SSc, both in terms of capillaroscopic patterns and history of digital ulcers, confirming microcirculation as the earliest involved vascular district. Macrovascular alterations (plaques, stenoses, occlusions, aneurysms) were more frequent in SSc (52.9%) and VEDOSS (50.0%) than in PRP (21.4%), delineating a potential continuum of macrovascular involvement already in early disease phases, although not reaching statistical significance. Neither SCORE2 nor carotid IMT significantly differed among groups, suggesting that conventional tools do not capture the excess vascular risk in SSc. VCAM-1 levels were significantly higher in SSc patients compared with VEDOSS and PRP, whereas ICAM-1 and CEC counts were increased in SSc relative to controls, indicating a progressive gradient of endothelial activation and damage along the disease spectrum. No significant differences in circulating cytokines were observed between PRP and VEDOSS, suggesting that endothelial activation mechanisms are not yet fully established in very early stages. In subjects with ultrasound evidence of atherosclerosis, FMD was reduced and VCAM-1 levels were higher compared with patients without atherosclerosis, supporting a systemic endothelial dysfunction integrating micro- and macroangiopathy.
Conclusions. The findings of this study are consistent with the “unified vascular framework,” in which SSc emerges as a systemic vascular disease driven by endothelial injury, characterized by a continuum of micro- and macrovascular damage already present in early disease phases (VEDOSS). The dissociation between estimated cardiovascular risk and actual vascular burden highlights the need to develop SSc-specific predictive scores incorporating endothelial biomarkers such as VCAM-1, ICAM-1, and CECs. These markers, together with instrumental indicators of vascular damage, may contribute to the identification of high-risk phenotypes and guide early therapeutic strategies aimed at endothelial protection. We observed a higher atherosclerotic burden affecting both VEDOSS and SSc to a similar extent, implying early macrovascular damage in the disease course. However, this early atherogenic process appears to be independent of endothelial dysfunction, since increases in endothelial activation markers and circulating endothelial cells became significant only at more advanced stages. Multicenter studies with larger cohorts and longitudinal follow-up are required to confirm and validate these findings
Water Mixing and Quality in Semi-Enclosed Sea Basins: The Adriatic and Gemlik Bay Cases
No full textI bacini marini semi-chiusi sono particolarmente vulnerabili al degrado della qualità dell'acqua poiché lo scambio limitato con il mare aperto aumenta il tempo di residenza, mentre la stratificazione verticale di densità inibisce il mescolamento e la ventilazione delle acque profonde. In tali sistemi, la concomitanza di lunghi tempi di rinnovo e forti interfacce termoaline può favorire la persistenza di nutrienti, contaminanti e sedimenti sospesi, aumentando la probabilità di eutrofizzazione, impatti sulla torbidità ed esaurimento dell'ossigeno nelle acque di fondo. All'interno di questo quadro generale, questa tesi sviluppa e applica approcci di modellazione basati sulla fisica per la valutazione della qualità dell'acqua, in particolare per quantificare il rinnovo e la ritenzione in bacini stratificati e per fornire indicatori pratici per la valutazione degli impatti della risospensione dei sedimenti associati alle operazioni offshore. In primo luogo, è stato sviluppato e validato un modello idrodinamico tridimensionale ad alta risoluzione Delft3D per la Baia di Gemlik (Mar di Marmara), un bacino semi-chiuso ampiamente segnalato come una delle aree più colpite dall'inquinamento del Mar di Marmara, caratterizzato da ricorrente arricchimento di nutrienti, eventi di fioritura algale e bassi livelli di ossigeno sul fondo durante i periodi stratificati, utilizzando profili CTD in situ provenienti da condizioni stagionali contrastanti. Il modello riproduce con alta fedeltà la struttura a due strati osservata e le caratteristiche nette di aloclino e termoclino, mentre il prodotto di rianalisi Copernicus mostra bias sistematici, tra cui salinità superficiali più basse e strati di interfaccia eccessivamente diffusi, limitando la sua idoneità per valutazioni focalizzate sulla stratificazione in piccoli bacini. L'analisi basata su traccianti fornisce la prima stima quantitativa del tempo di residenza dell'acqua nella Baia di Gemlik, rivelando un rapido rinnovo negli strati superiori (≈25–50 giorni) ma una forte ritenzione in profondità, con acque al di sotto dei 60 m che mostrano una persistenza superiore agli 8 mesi, e lo strato di fondo che si avvicina agli 11 mesi. Questi risultati evidenziano come la stratificazione possa isolare le acque di fondo e amplificare la vulnerabilità all'accumulo di inquinanti e all'ipossia. In secondo luogo, viene proposta una metodologia precauzionale e basata sulla fisica per valutare l'impronta sulla qualità dell'acqua della risospensione dei sedimenti durante la rimozione completa di piattaforme offshore nel Mar Adriatico italiano. Un ampio set di simulazioni CORMIX del trasporto di sedimenti scavati, che copre condizioni ambientali e operative rappresentative, è sintetizzato in relazioni predittive per le distanze caratteristiche di impatto, consentendo uno screening rapido dell'estensione del potenziale pericolo quando le informazioni dettagliate sul sito sono limitate. I risultati indicano che gli impatti del pennacchio sono transitori e spazialmente limitati: la diluizione supera il 99% entro pochi giorni; gli effetti dei sedimenti depositati rimangono limitati (<6,6 km), mentre i sedimenti fini in sospensione possono viaggiare più lontano (fino a 14,6 km) ma rimangono principalmente vicino al fondale marino. Le risultanti funzioni predittive forniscono uno strumento trasferibile e orientato alle decisioni per supportare la pianificazione preliminare, lo screening ambientale e la progettazione delle misure di mitigazione per lo smantellamento (decommissioning) in contesti costieri sensibili. Complessivamente, la tesi trasmette due messaggi generali per la gestione della qualità dell'acqua nei bacini semi-chiusi: i) è essenziale la modellazione 3D ad alta risoluzione per superare i bias dei dati di rianalisi sulla stratificazione; (ii) indicatori predittivi semplificati sono efficaci per tradurre complesse simulazioni di sedimenti in strumenti gestionali pratici. Semi-enclosed marine basins are particularly vulnerable to water-quality degradation because restricted exchange with the open sea increases residence time, while vertical density stratification inhibits mixing and deep-water ventilation. In such systems, the coincidence of long renewal timescales and strong thermohaline interfaces can promote the persistence of nutrients, contaminants, and suspended sediments, increasing the likelihood of eutrophication, turbidity impacts, and bottom-water oxygen depletion. Within this general framework, this thesis develops and applies physics-based modelling approaches for the water quality assessment, in particular to quantify renewal and retention in stratified basins and to provide practical indicators for assessing sediment-resuspension impacts associated with offshore operations.
Firstly, a high-resolution three-dimensional Delft3D hydrodynamic model is developed and validated for Gemlik Bay (Sea of Marmara), a semi-enclosed basin widely reported as one of the most pollution-impacted areas of the Marmara Sea, with recurrent nutrient enrichment, bloom events, and low bottom oxygen during stratified periods, using in-situ CTD profiles from contrasting seasonal conditions. The model reproduces the observed two-layer structure and sharp halocline/thermocline features with high fidelity, while the Copernicus reanalysis product exhibits systematic biases, including fresher surface salinities and overly diffuse interface layers, limiting its suitability for stratification-focused assessments in small basins. Tracer-based analysis provides the first quantitative estimate of water residence time in the Gemlik Bay, revealing rapid renewal in the upper layers (≈25–50 days) but strong retention at depth, with waters below 60 m exhibiting persistence exceeding 8 months, with the bottom layer approaching 11 months. These results highlight how stratification can isolate bottom waters and amplify vulnerability to pollutant accumulation and hypoxia.
Secondly, a physics-based and precautionary methodology is proposed to evaluate the water-quality footprint of sediment resuspension during complete offshore-platform removal in the Italian Adriatic Sea. A large set of CORMIX simulations of excavated-sediment transport, spanning representative environmental and operational conditions is synthesized into predictive relationships for characteristic impact distances, enabling rapid screening of potential hazard extension when detailed site information is limited. Results indicate that plume impacts are transient and spatially constrained: dilution exceeds 99% within days; deposited sediment effects remain limited (<6.6 km), while suspended fine sediments can travel farther (up to 14.6 km) but remain primarily near the seabed. The resulting predictive functions provide a transferable, decision-oriented tool to support early-stage planning, environmental screening, and mitigation design for decommissioning in sensitive coastal settings.
Overall, the thesis delivers two general messages for water-quality management in semi-enclosed basins: (i) when stratification controls renewal and vertical exchange, high-resolution three-dimensional hydrodynamic modelling is essential, as coarse reanalysis products may exhibit systematic biases in surface properties and interface-layer representation; and (ii) for sediment-resuspension risks associated with offshore operations, robust yet simple indicators (e.g., impact-distance predictors) can translate complex plume simulations into actionable metrics for regulators and practitioners