Politecnio die Bari - Catalogo di prodotti della Ricerca
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From knowledge to action: Assessing the effectiveness of immersive virtual reality training on safety behaviors in confined spaces using the Kirkpatrick model
Get PDFSafety in the industrial sector is paramount, with national legislations establishing specific regulations to reduce accidents. These regulations emphasize risk removal and proper operator training as preventive measures. However, traditional training can be time-consuming and costly, leading companies to meet only the minimum requirements. In particular, confined spaces pose significant dangers, often resulting in fatal, cascading accidents due to a lack of proper safety procedures. Therefore, effective training is crucial to mitigate these risks. Advanced technologies like Immersive Virtual Reality (IVR) present new opportunities for cost-effective and extensive training campaigns by eliminating the risks associated with real environment training, offering a safe yet realistic experience. Despite the widespread adoption of IVR training applications in industrial research, there is a notable lack of systematic approaches to evaluate their effectiveness. Conducting such evaluations is crucial to ascertain their impact on essential training outcomes, including participant engagement, knowledge transfer, and enhanced safety behavior during work activities. To address this gap, we developed an IVR-based training platform for confined space safety procedures and established a systematic validation procedure using the Kirkpatrick model to assess its effectiveness compared to conventional training methods. Results demonstrate that IVR training provides an excellent user experience, better knowledge transfer than the traditional approach, and improved performance in simulated procedures, reducing execution errors and completion times. This dual focus on creating and validating the IVR system underscores its potential as an effective training tool in hazardous environments such as confined spaces, where proper training can prevent tragic fatalities
Exploring the impact of thermal fluctuations on continuous models of adhesion
Get PDFAdhesion and deadhesion processes at the interface between an object and a substrate are well-established phenomena in the realm of materials science and biophysics. These processes can be profoundly influenced by thermal fluctuations, a phenomenon empirically validated through numerous experimental observations. While discrete models have traditionally served as a foundation for understanding this intricate interplay, this paper seeks to bridge the gap between such discrete representations and the continuous models that more accurately reflect experimental scenarios. To achieve this objective, we initially adopt discrete models comprising n elements, selected such that their physical parameters converge towards the continuum limit as n approaches infinity. This thoughtful scaling ensures that the discrete system retains its relevance in the context of continuous media. Leveraging principles from Statistical Mechanics and Griffith-type total energy minimization approaches, we employ this scaled discrete model to investigate the impact of temperature in continuous adhesion phenomena. As a result, we obtain an analytical model to account for the decrease of the decohesion threshold depending on thermal (entropic) energy terms. Interestingly, our approach demonstrates that continuous adhesion models invariably exhibit phase transitions, whose critical temperatures can be derived through closed-form calculations. By elucidating these critical temperature values, this work enhances our understanding of adhesion processes within continuous media and opens new avenues for the exploration of adhesion-related phenomena in diverse scientific disciplines. Finally, the comparison with some experimental results is discusse
Housing Overcrowding: Relationships and Challenges in the Contemporary Era
No full textThe home is a fundamental part of life, serving as a refuge and consuming significant economic and material resources. However, housing issues have become complex, gaining social and regulatory interest. Factors like housing size, crowding index, social housing, and housing codes significantly impact living quality and well-being. This research investigates domestic space and its relationship with users in new housing developments. It examines how standards influence living space design to meet needs for adequate space and social sustainability through social housing policies. The study analyses the crowding index as a key quality parameter, proposing scenarios for evolving home concepts to meet contemporary needs. The analysis considers demographic changes, household structure shifts, and the impact of working conditions on housing sustainability and social cohesion. It addresses economic challenges in securing adequate housing and managing family health and education, emphasising the need for inclusive housing policies. The paper views housing as crucial for dignity and sustainability, advocating for a holistic approach that sees housing as an integrated ecosystem supporting social and individual dynamics. It highlights how social housing models can combat overcrowding, improve life quality, and promote social inclusion
Digital twin for industrial systems: data-driven approaches for monitoring and control
No full textI sistemi industriali (SI), che vanno dalle linee di produzione alle reti più avanzate, richiedono sempre più meccanismi di controllo più intelligenti e intelligenti a causa delle complessità della moderna automazione industriale.
Tuttavia, le tecniche tradizionali basate su modelli spesso non riescono a catturare la complessità di questi sistemi a causa delle non linearità intrinseche del sistema e della crescita esponenziale dei dati di processo.
Di conseguenza, la tecnologia data-driven (DD) si è affermata come un enabler fondamentale per la trasformazione digitale dei moderni ISs, promuovendo soluzioni di controllo integrate e adattative conformi alla cosiddetta Industria 4.0. Questa evoluzione introduce tecnologie avanzate, tra cui l'Internet delle cose, il machine learning e i sistemi cyber-fisici -in particolare il Digital Twin -, che insieme consentono ai sistemi di rispondere in modo adattativo alle richieste di produzione in tempo reale e ai cambiamenti ambientali.
Nonostante le metodologie DD rappresentino un'alternativa promettente per migliorare il controllo e la diagnostica dei sistemi, nonché per preservare le prestazioni del processo sfruttando i dati in tempo reale, esistono ancora diverse limitazioni tecniche che ne impediscono l'applicazione diffusa nei sistemi del mondo reale.
In tale contesto, questa tesi indaga il potenziale dei metodi DD per monitorare e controllare gli IS, affrontando le loro sfide più moderne. Per raggiungere questo obiettivo, vengono perseguite due direzioni principali di ricerca.
La prima parte della tesi esplora la modellazione dinamica DD per il controllo di processo, sviluppando metodi di controllo indiretto DD per ottimizzare le prestazioni del processo.
Tra i contributi in tal senso figurano (i) la progettazione di tecniche di controllo predittivo del modello per il processo di imbutitura, che migliora in modo significativo l'efficienza del processo e la qualità del prodotto, e (ii) un solido schema di controllo per lesistemi non lineari affini che utilizzano l'identificazione subspaziale della dinamica non lineare e la programmazione semidefinita on-li ne. Questo approccio di controllo offre stabilità e prestazioni superiori per una tale classe di modelli non lineari senza approssimarne la dinamica.
La seconda parte della tesi indaga i metodi di controllo adattivo e di rilevamento dei guasti DD per preservare le prestazioni dei processi industriali.
Ciò include (i) un controllo predittivo adattivo del modello per attuatori servo idraulici (HSA) basato su valvole di controllo del flusso e (ii) una nuova struttura di controllo adattivo di riferimento del modello per HSA multicamera basata su valvole di controllo della pressione. Inoltre, (iii) un nuovo algoritmo di clustering limitato adattivo è introdotto per il rilevamento in tempo reale dei guasti degli IS, distinguendo efficacemente tra condizioni di lavoro nominali e non nominali in un contesto operativo dinamico.Industrial Systems (ISs), ranging from manufacturing lines to more advanced networks, increasingly require smarter and smarter control mechanisms due to the complexities of modern industrial automation.
However, traditional model-based techniques often fall short in capturing the complexities of these systems due to the inherent system nonlinearities and the exponential growth of process data.
As a result, Data-Driven (DD) technology has emerged as a pivotal enabler for the digital transformation of modern ISs, promoting integrated and adaptive control solutions compliant to the so-called Industry 4.0. This evolution introduces advanced technologies, including Internet of Things, Machine Learning, and cyber-physical systems --especially Digital Twin--, which together allow systems to adaptively respond to real-time production demands and environmental changes.
Despite DD methodologies represent a promising alternative for improving system control and diagnostics, as well preserving process performance by leveraging real-time data, several technical limitations hindering their widespread application in real-world systems still exist.
Within such a context, this thesis investigates the potential of DD methods for monitoring and controlling ISs, addressing their most modern challenges. To this aim, two primary research directions are pursued.
The first part of the thesis explores DD dynamic modeling for process control, developing indirect DD control methods for optimizing the process performance.
Contributions in this direction include (i) the design of Model Predictive Control techniques for the deep drawing process, which significantly enhances process efficiency and product quality, and (ii) a robust control scheme for input-affine nonlinear systems using Subspace Identification of Nonlinear Dynamics and online Semi-Definite Programming. This control approach offers superior stability and performance for such a class of nonlinear models without approximating their dynamics.
The second part of the thesis investigates DD adaptive control and fault detection methods for preserving the performance of industrial processes.
This includes (i) an Adaptive Model Predictive Control for Hydraulic Servo Actuators (HSAs) based on flow control valves, and (ii) a novel Model Reference Adaptive Control framework for multi-chamber HSAs based on pressure control valves. Additionally, (iii) a new Adaptive Constrained Clustering algorithm is introduced for the real-time fault detection of ISs, effectively distinguishing between nominal and non-nominal working conditions in a dynamic operational context
Viscoelastic friction in sliding a non-cylindrical asperity
Get PDFWe investigate the 2D contact problem of sliding a non-cylindrical punch on a viscoelastic halfplane, assuming a power law shape xk with k>2 . We find with a full boundary element numerical solution that the Persson analytical solution for friction, which works well for the cylindrical punch case assuming the pressure remains identical in form to the elastic case, in this case leads to significant qualitative errors. However, we find that the friction coefficient follows a much simpler trend; namely, we can use as a first approximation the solution for the cylinder, provided we normalize friction coefficient with the modulus and mean pressure at zero speed, despite that we show the complex behaviour of the pressure distribution in the viscoelastic regime. We are unable to numerically solve satisfactorily the ill-defined limit of sharp flat punch, for which Persson's solution predicts finite friction even at zero speed
Galactic transient sources with the Cherenkov Telescope Array Observatory
No full textA wide variety of Galactic sources show transient emission at soft and hard X-ray energies: low-mass and high-mass X-ray binaries containing compact objects, isolated neutron stars exhibiting extreme variability as magnetars as well as pulsar wind nebulae. Although most of them can show emission up to MeV and/or GeV energies, many have not yet been detected in the TeV domain by Imaging Atmospheric Cherenkov Telescopes. In this paper, we explore the feasibility of detecting new Galactic transients with the Cherenkov Telescope Array Observatory (CTAO) and the prospects for studying them with Target of Opportunity observations. We show that CTAO will likely detect new sources in the TeV regime, such as the massive microquasars in the Cygnus region, low-mass X-ray binaries with low-viewing angle, flaring emission from the Crab pulsar-wind nebula or other novae explosions, among others. Since some of these sources could also exhibit emission at larger timescales, we additionally test their detectability at longer exposures. We finally discuss the multi-wavelength synergies with other instruments and large astronomical facilities
Simulation-Based Effectiveness Evaluation of “Best Strategies” for Single and Multi-Risk Mitigation in Typological Historic Squares
No full textSquares in historical city centres are challenging scenarios for disaster risk mitigation. Besides their physical vulnerability, they are “hot spots” in both terms of morphology and human factors, being also characterized by overcrowding and the presence of vulnerable users. Thus, mitigation strategies should be designed to be effective in various single-risk and multi-risk scenarios, depending on hosted users’ emergency needs and behaviours. This paper aims at determining optimal mitigation strategies against rising temperatures, air pollution, terrorist acts and earthquakes and their combination, using a behavioural simulation-driven methodology. Single risk Key Performance Indicators are defined to combine users’ exposure and vulnerability to square features (i.e. morphology, physical vulnerability, climatic attributes, hazard probabilities, and damage levels). Multi-risk metrics are then developed combining these indicators. Input data for indicators and metrics are calculated through validated simulation models, and applications to relevant typological configurations of Italian historic squares are performed considering the scenarios before and after the implementation of literature-based strategies affecting users’ behaviours. Results show how implementing greenery and engineered planters can be selected as “best strategies” to face the given risks, since they can both decrease effects on users’ health and support evacuation flows in emergency conditions. Being tested in typological (idealized) conditions, this study provides an initial strategies inventory that can be further customized in real-world squares. Decision-makers can evaluate their specific impact using the proposed simulation-based methodology and the proposed indicators and metrics
Rapid detachment of a rigid sphere adhered to a viscoelastic substrate: An upper bound model incorporating Maugis parameter and preload effects
No full textFor a typical adhesive contact problem, a rigid sphere initially adhered to a relaxed viscoelastic substrate is pulled away from the substrate at finite speeds, and the pull-off force is often found to depend on the rate of pulling. Despite significant theoretical advancements in this area, how the apparent adhesion enhancement is affected by the Maugis parameter and preload remains unclear, and existing models are sometimes contentious. In this work, we revisit this adhesive contact problem and propose a theoretical model to predict the upper bound detachment behavior when the pulling speed approaches infinity. Our analysis reveals that the apparent work of adhesion can always be enhanced, regardless of the Maugis parameter, when the initial contact radius exceeds a critical threshold. Conversely, when the initial contact radius is below this critical value, the adhesion enhancement becomes limited and depends on both the Maugis parameter and the preload condition. Further model calculations suggest that the critical initial contact radius is dependent on the Maugis parameter. In the JKR-like regime, this critical radius converges to a constant value, whereas in the DMT-like regime, it diverges rapidly following an inverse power law with respect to the Maugis parameter. As a result, observing adhesion enhancement is generally more challenging in DMT-like contacts compared to JKR-like contacts. In the meantime, our model also suggests that the adhesion enhancement arises from the expansion of the cohesive zone area due to the viscoelastic properties of the material not only within the cohesive zone but also in the intimate contact zone. Overall, our findings offer a more comprehensive understanding of viscoelastic effects in adhesive contacts, which can be used to rationally predict or optimize adhesion strength in viscoelastic interfaces
Accessibilità ampliata nel palinsesto architettonico urbano. Strategie e strumenti integrati per il progetto di valorizzazione culturale nell’era del digitale.
Get PDFLa tesi di dottorato dal titolo “Accessibilità ampliata nel palinsesto architettonico
urbano. Strategie e strumenti integrati per il progetto di valorizzazione
culturale nell’era del digitale” indaga le possibilità di integrare il requisito
dell’accessibilità nei contesti urbani storici. Condotta nell’ambito del XXXVII
ciclo del Dottorato di ricerca in “Conoscenza e innovazione nel progetto per
il patrimonio” del Politecnico di Bari, esplora come l’accessibilità sia considerata
oggi non solo una sfida, ma un’opportunità irrinunciabile per la valorizzazione
e rigenerazione del patrimonio culturale. La ricerca propone la
costruzione di un nuovo approccio metodologico integrato per la progettazione
architettonica, sostenuto dai principi di inclusività e sostenibilità per
un progetto sensibile alle dinamiche culturali e sociali contemporanee.
Attraverso un’analisi interdisciplinare e multiscalare, vengono studiati casi
nazionali e internazionali per definire modelli metodologici innovativi e applicabili
a diverse scale e contesti. In particolare, lo sviluppo di un modello
esigenziale-prestazionale e l’integrazione di strumenti digitali permettono di
valorizzare l’interazione tra patrimonio, architettura e accessibilità.
La ricerca si specializza poi nel caso studio di Bitonto, con particolare riferimento
al circuito delle mura urbiche, un contesto urbano di grande valenza
identitaria, storica e culturale, dove è possibile applicare la metodologia e le
strategie progettuali sviluppate. La tesi mira a proporre un modello scalabile
e replicabile di rigenerazione dei palinsesti architettonici e urbani storici,
che promuova un accesso inclusivo e un uso contemporaneo del patrimonio,
delineando nuove prospettive progettuali per il futuro della città storica.The thesis entitled "Wider accessibility in the architectural and urban palimpsest. Integrated strategies and tools for the cultural enhancement project in the digital age", investigates the possibilities of integrating the accessibility requirement in historical urban contexts. Carried out within the framework of the XXXVII cycle of the doctoral programme 'Knowledge and Innovation in Heritage Design' of the Politecnico di Bari, it examines how accessibility is now considered not only a challenge but also an indispensable opportunity for the valorisation and regeneration of cultural heritage. The research proposes the construction of a new integrated methodological approach to architectural design, based on the principles of inclusiveness and sustainability for a project sensitive to contemporary cultural and social dynamics. Through an interdisciplinary and multi-scalar analysis, national and international cases will be studied in order to define innovative methodological models applicable to different scales and contexts. In particular, the development of a demand-supply model and the integration of digital tools allow for a better interaction between heritage, architecture and accessibility. The research then specialises in the case study of Bitonto, with particular reference to the circuit of the city walls, an urban context of great identity, historical and cultural value, where the methodology and design strategies developed can be applied. The thesis aims to propose a scalable and replicable model for the regeneration of historic architectural and urban palimpsests, promoting inclusive access and contemporary use of heritage, and outlining new design perspectives for the future of the historic city
Innovative technologies for the sustainable management of WEEE: combined treatments for material recovery
No full textLa crescente domanda di Apparecchiature Elettriche ed Elettroniche (AEE) ha portato alla generazione di un flusso di rifiuti in rapido aumento a livello globale, noto con l'acronimo RAEE (Rifiuti da Apparecchiature Elettriche ed Elettroniche). In particolare, la percentuale maggiore è rappresentata da lavastoviglie, lavatrici, forni, piani cottura e stufe elettriche che, nel contesto italiano, costituiscono i cosiddetti "Grandi Bianchi" e rientrano nel raggruppamento R2. Questi rifiuti contengono metalli ferrosi e non ferrosi, come rame e alluminio, oltre a plastica, vetro e altri materiali; questa composizione eterogenea rende i RAEE una preziosa risorsa secondaria. Tuttavia, alcune apparecchiature possono contenere ritardanti di fiamma bromurati e metalli pesanti, che costituiscono un rischio per la salute umana e per l'ambiente.
In questo contesto, la presente tesi mira alla valutazione tecnica e ambientale di tecnologie innovative, con l'obiettivo di ottimizzare il recupero di materia dai RAEE R2 e minimizzare le frazioni destinate allo smaltimento in discarica.
Le attività condotte presso un impianto di trattamento dei RAEE R2, situato nel sud Italia, hanno consentito di analizzare l’attuale ciclo di gestione di questi rifiuti. È stato calcolato il bilancio di massa dell’intero processo di trattamento, attraverso la caratterizzazione dei flussi in entrata e in uscita e sono state determinate le efficienze di separazione dei metalli ferrosi, dei metalli non ferrosi e delle plastiche che sono risultate essere pari rispettivamente a circa il 93%, il 78% e il 91%.
I test di trattabilità, condotti in laboratorio, hanno mirato a sperimentare alcune tecnologie innovative di recupero di materia dai RAEE R2.
Una tavola densimetrica prototipale è stata testata per la separazione del rame e dell’alluminio, due metalli non ferrosi che attualmente costituiscono un unico flusso in uscita nello schema tipico di trattamento dei “Grandi Bianchi”. I risultati mostrano che l’impiego di questa tecnologia, in condizioni specifiche, può garantire elevati tassi di recupero e purezza (prossimi al 100%), tali da consentire il reintegro di questi metalli non ferrosi nel ciclo economico come materia prima seconda (MPS).
Al fine di ottimizzare il recupero dei polimeri plastici tipicamente presenti negli e-waste, come polipropilene (PP), polistirene (PS), polivinilcloruro (PVC) e poliammide 6 (PA6), sono stati condotti i test di trattabilità di due soluzioni innovative: la tecnologia ad umido sink-float, utilizzando la melassa come soluzione green, e la separazione tribo-elettrostatica, testando un impianto prototipale costituito da un tribo-charger e un sistema di selezione delle particelle plastiche in funzione della loro carica elettrica superficiale. I risultati dimostrano che la tecnica di separazione sink-float è un metodo efficace e sostenibile per separare e selezionare i polimeri plastici dai RAEE, consentendo di ottenere efficienze di recupero prossime al 100%. Anche la separazione tribo-elettrostatica rappresenta una soluzione efficace. Infatti, i risultati mostrano che, in condizioni specifiche, è possibile ottenere un grado di purezza del PP e del PS pari a circa l’85% e un tasso di recupero per il PA6 e per il PVC pari al 91%.
I dati sperimentali ottenuti suggeriscono che l'implementazione in scala industriale di queste tecnologie innovative, associate a quelle consolidate, potrebbe ottimizzare il recupero di materia dai RAEE R2, consentendo di superare gli obiettivi minimi di recupero fissati dalla stringente Direttiva Europea per questa categoria di rifiuti.
Infine, è stata condotta una valutazione ambientale attraverso l'analisi Life Cycle Assessment (LCA) dell'attuale schema di trattamento dei RAEE R2, basata sul caso studio dell'impianto del sud Italia, e di un nuovo modello di gestione di questi rifiuti, che integra le tecnologie innovative investigate. I risultati confermano la sostenibilità ambientale della nuova configurazione rispetto al processo tradizionale.Increasing demand for Electrical and Electronic Equipment results in the generation of a rapidly growing waste stream worldwide, known by the acronym WEEE (Waste Electrical and Electronic Equipment). In particular, the largest percentage is represented by dishwashers, washing machines, ovens, hobs and electric stoves which, in the Italian context, represent the 'Large Whites' and fall into the R2 grouping. This kind of waste contains ferrous and non-ferrous metals, e.g. copper and aluminium, as well as plastic, glass and other materials; this heterogeneous composition makes WEEE a valuable secondary resource. However, some appliances may contain brominated flame retardants and heavy metals, which pose a risk to human health and the environment.
In this context, this thesis aims at the technical and environmental evaluation of inno-vative technologies, with the objective of optimising material recovery from WEEE R2and minimising the fractions going to landfill.
Activities conducted at a WEEE R2 treatment plant, located in southern Italy, allowed an analysis of the current management cycle of this kind of waste. The mass balance of the entire treatment process was calculated by characterizing the input and output flows, and the separation efficiencies for ferrous metals, non-ferrous metals, and plastics were determined, found to be approximately 93%, 78%, and 91%, respec-tively.
The treatability tests, conducted in the laboratory, aimed to experiment with some innovative technologies for material recovery from WEEE R2. A prototype densimetric table was tested for the separation of copper and aluminium, two non-ferrous metals that currently form a single output flow in the typical treatment scheme for "Large Whites". The results show that, under specific conditions, the use of this technology can ensure high recovery rates and purity (close to 100%), allowing these non-ferrous metals to be reintegrated into the economic cycle as secondary raw material.
In order to optimise the recovery of the plastic polymers typically found in e-waste, such as polypropylene (PP), polystyrene (PS), polyvinyl chloride (PVC) and polyamide 6 (PA6), the treatability of two innovative solutions was tested: the wet sink-float technology, using molasses as a green solution, and tribo-electrostatic separation, testing a prototype plant consisting of a tribo-charger and a system for sorting plastic particles according to their surface electrical charge. The results show that the sink-float separation technique is an effective and sustainable method for separating and sorting plastic polymers from WEEE, allowing recovery efficiencies close to 100 %. Tribo-electrostatic separation is also an effective solution. In fact, results show that, under specific conditions, PP and PS purity of around 85% and recovery rates for PA6 and PVC of 91% can be achieved.
The experimental data obtained suggest that the industrial-scale implementation of these innovative technologies, coupled with the established ones, could optimise material recovery from R2 WEEE, making it possible to exceed the minimum recovery targets set by the stringent European Directive for this category of waste.
Finally, an environmental assessment was conducted by means of a Life Cycle As-sessment (LCA) of the current R2 WEEE treatment scheme, based on the case study of the southern Italian plant, and of a new management model for this waste, which integrates the innovative technologies investigated. The results confirm the environ-mental sustainability of the new configuration compared to the traditional process