Politecnio die Bari - Catalogo di prodotti della Ricerca
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Toward human-centric Industry 5.0: a framework for cognitive workload assessment in maintenance and assembly
No full textIn the transition from Industry 4.0 to Industry 5.0 (I5.0), the focus of manufacturing is shifting toward human-centric, sustainable, and resilient systems. A key challenge in this evolution is managing the cognitive workload (CWL) of operators, especially during complex tasks such as maintenance and assembly. These activities are central to industrial operations and often involve high mental demands due to task variability, decision-making under pressure, and human–machine collaboration. Despite a growing body of research on CWL, there remains a lack of clarity regarding the most suitable assessment methods for specific industrial tasks. This study addresses that gap by conducting a systematic literature review to identify how CWL is measured across distinct categories of maintenance and assembly operations, the results of which were used to develop a framework for measuring CWL and a matrix of CWL assessment guidelines. Findings show that different task categories present distinct cognitive demands, which influence the selection of CWL assessment methods. Routine and structured tasks are typically assessed using subjective or basic physiological measures, while more complex and dynamic tasks increasingly require multimodal approaches combining subjective, physiological, and performance-based data. Additionally, the review revealed intra-domain similarities and inter-domain differences that highlight the need for task-specific CWL evaluation strategies. Based on these insights, the study proposes a framework that maps suitable CWL assessment methods to categories of maintenance and assembly tasks, along with a CWL assessment guidelines matrix to support method selection according to task complexity and operational impact. By offering a structured approach to CWL evaluation, this work contributes to the transition toward adaptive, human-centric industrial systems in line with the I5.0 paradigm
Effect of the Tank Volume and Aspect Ratios on the Storage Capacity in Solid-State Hydrogen Storage: A Numerical Assessment
No full textStoring hydrogen in solid state is gaining attention enabling for overcoming simultaneously two specific limits of conventional hydrogen storage technologies: storage capacity and safety. Currently, hydrogen is stored as compressed gas (usually, at either 350 or at 700 bar), reaching densities ranging from 24.5 to 41.4 kg/m3, but requiring a significant compression work and determining several safety issues; otherwise, it can be stored in liquid state under cryogenic conditions (70.8 kg/m3 at 1 bar and 20 K), but requiring a great amount of energy for liquefaction (about 12.5 kWh/kg) and costs to keep it liquid. In solid state context, physisorption (also said adsorption) mechanism has been recognized as an attractive technique for its capability of storing hydrogen in a porous structure, with weaker bonds, differently from chemisorption mechanism where hydrogen molecules chemically bonds to the absorbing material forming, for instance, metal hydrides. During adsorption, heat is released and thermal management can become an issue when the tank volume is increased. This work aims to numerically investigate the effect of increasing the tank volume on the solid-state hydrogen storage capacity. Moreover, the effect of the tank aspect-ratio is considered. The investigation has been carried out through Computational Fluid Dynamic analyses. The modified Dubinin-Astakhov isotherm model has been taken into account to describe the isotherm sorption during charge, dormancy, and discharge processes. Initially, the model has been validated on a 2.5 dm3 tank, against experimental results available in the literature; then, the geometry has been scaled by a factor of 10, and several aspect ratio considered. The numerical study was conducted considering three different aspect ratios (i.e., 5, 8.5, and 15), whilst keeping the internal volume constant. In this work, it is shown that larger aspect ratios can lead to improved adsorbed mass and decreased maximum temperatures in the system
Plasma deposition of hybrid nanocomposite coatings from aerosol containing TiO2 and AgNO3
No full textTiO2 nanocomposites are widely studied for the photocatalytic degradation of organic pollutants. Coupling TiO2, an n-type semiconductor, with an electron-sink co-catalyst effectively reduces electron-hole recombination, thereby enhancing photocatalytic efficiency. In this study, photoactive nanocomposite coatings were developed for the first time by depositing TiO2 nanoparticles and AgNO3 in various ratios within a siloxane matrix via aerosol-assisted atmospheric pressure plasma deposition. The photocatalytic activity of these coatings was assessed by monitoring the discoloration of a solution of methylene blue under UV irradiation (λ = 254 nm) using UV–Vis spectroscopy, with recyclability tested over three cycles. The chemical composition, structure, and morphology have been also assessed. The beneficial effect of the silver addition was more evident for coatings deposited with a low amount of TiO2. Moreover, repeated use of the photocatalytic coatings led to enhanced performance, due to partial matrix degradation and photoreduction of Ag(I) to Ag(0), as confirmed by X-Ray Photoelectron Spectroscopy
On the effect of thermal strains in slender prestressed concrete beams
No full textIn construction sector, prestressed concrete beams are commonly used, even in ordinary buildings; as a consequence, their exposure to various risk factors, including fires or high thermal gradients, is quite high. Extensive research has focused on concrete structures under extreme loading conditions, but slender prestressed members have proven unique and challenging in the understanding of mechanical response and their numerical modelling, particularly regarding the interaction between thermal gradients and prestressing forces. In fact, unlike ordinary concrete beams and columns, these structures are particularly sensitive to temperature changes and temperature gradients. In addition, their thermo-mechanical response is further complex due to the interaction of thermal loads with pre-existing prestressing stresses, which vary over time as a function of temperature field. This work explores this dual behavior by means of numerical simulations including temperature-dependent material properties, focusing on the thermal expansion coefficient (alpha) and thermal transient creep. Using a staggered scheme finite element modelling, the analysis applies a coupled thermo-mechanical approach. The model has been validated on a series of experimental tests carried out at Polytechnic of Bari. The comparison showed the model capability to capture the influence of temperature-dependent strains on these slender structures. The results highlight how even minor variations in thermal properties can affect the mechanical response, providing insights essential for the safe design of prestressed concrete elements under thermal loads
Costruire con la terra: tra memoria costruttiva e innovazione progettuale
No full textIl workshop “Cultura Material no Alentejo” ha evidenziato come la terra cruda, oltre che materiale costruttivo, possa divenire dispositivo critico per ripensare il progetto di architettura. La sua reversibilità, prossimità e memoria ne fanno strumento per una pratica contestuale, etica e trasformativa. Il progetto, inteso come atto di cura e relazione, supera la forma per divenire processo culturale e ambientale, capace di generare immaginari alternativi, abitare il tempo e risignificare l’eredità costruita
Flexible electrochemical sensor for detecting chlorine ions in sweat
No full textIn this work we present a flexible sensor for Cl ion concentration based on electrochemical measurements, suitable for a rapid screening method of cystic fibrosis. The electrodes have been fabricated by depositing an Ag layer subsequently reduced to Ag/AgCl with two different procedures. The developed electrodes show sensitivity around 52mV/decade in [Cl-] concentration, stability times around 30 minutes, minimum detectable concentration around 240nM and good reproducibility between the different samples. The readout implementable also on flexible support is also shown and characterized. The readout is a reusable support while the electrodes should be replaced at each measurement. The resolution of the tool is comparable with the instrumental equipment used as golden standard in laboratory
SISMOGRAFI DELLA MODERNITÀ. SPAZI E ARCHITETTURE PER IL COMMERCIO DI MARINO LOPOPOLO
No full textThis contribution aims to investigate the urban reality of the city of Bari during the period between
the two wars. Particular attention is paid to the ways in which the places of consumption became
rooted in the physical geography of the city, in the flows of mobility, in the models of urban
planning and architectural design. In order to do this, it was decided to address the design activity
of some of the most active designers in this field on the territory of the Apulian capital. Specifically,
the projects of the futurist architect Marino Lopopolo were examined in depth, identifying as a
case study that of the individual businesses, the shops he designed during the years of fascism
Analysis of the rapid tempering treatment on a high-strength boron steel in the martensitic state through physical simulation
No full textIn recent years, high-strength boron steels have become increasingly important in the automotive industry, particularly for structural components such as the B-pillar. These steels, when in a martensitic state, provide excellent safety performance while enabling the use of thinner sheets, which contributes to reducing the overall weight of vehicles. However, the inherent brittleness of martensite poses difficulties during the mechanical assembly process with other car body parts. One potential solution to enhance ductility is the application of rapid tempering, which is also valued for its lower energy consumption when compared to conventional tempering treatments. This study focuses on analyzing the softening behavior and associated microstructural evolution of martensitic 37MnB4 steel when subjected to rapid tempering cycles. Three distinct heating rates (10K/s, 100K/s, and 250K/s) and two holding times (0 s and 8 s) were considered. The findings indicate that rapid tempering leads to notable softening of the steel, with the highest degree of softening observed at tempering temperatures close to, specifically a few dozen degrees higher than, the eutectoid point at equilibrium, depending on both the heating rate and the holding time applied
Optimizing 3D printing process parameters for high-performance inflatable soft actuators
No full textInflatable actuators have shown great potential in soft robotics; however, the usage of 3D printing technologies is still at its infancy phase. This paper focuses on the usage of Material Extrusion (MEX) to advance the fabrication of soft inflatable actuators and enhance performance. Two different designs were studied and the softest thermoplastic elastomer available on the market was used. Printing parameters (i.e., infill direction, ironing and extrusion temperature) were investigated to maximize the elongation and improve the intra-layer adhesion which is crucial to achieve air-tightness. A design of experiments approach was used to analyze the effect of each process parameter on mechanical properties. Additionally, hyperplastic simulations were performed and benchmarked with experimental results. The relationship process parameters- mechanical properties- performance is evaluated, laying the foundation for a broader usage of MEX for the fabrication of soft inflatable actuators
Effect of Crestal Position on Bone–Implant Stress Interface of Three-Implant Splinted Prostheses: A Finite Element Analysis
No full textOptimizing stress distribution at the bone–implant interface is critical to enhancing the long-term biomechanical performance of dental implant systems. Vertical misalignment between splinted implants can result in elevated localized stresses, increasing the risk of material degradation and peri-implant bone resorption. This study employs three-dimensional finite element analysis (FEA) to evaluate the mechanical response of peri-implant bone under oblique loading, focusing on how variations in vertical implant platform alignment influence stress transmission. Four implant configurations with different vertical placements were modeled: (A) all crestal, (B) central subcrestal with lateral crestal, (C) lateral subcrestal with central crestal, and (D) all subcrestal. A 400 N oblique load was applied at 45° simulated masticatory forces. Von Mises stress distributions were analyzed in both cortical and trabecular bone, with a physiological threshold of 100 MPa considered for cortical bone. Among the models, configuration B exhibited the highest cortical stress, exceeding the physiological threshold. In contrast, configurations with uniform vertical positioning, particularly model D, demonstrated more favorable stress dispersion and lower peak values. Stress concentrations were consistently observed at the implant–abutment interface across all configurations, identifying this area as critical for design improvements. These findings underscore the importance of precise vertical alignment in implant-supported restorations to minimize stress concentrations and improve the mechanical reliability of dental implants. The results provide valuable insights for the development of next-generation implant systems with enhanced biomechanical integration and material performance under functional loading