Politecnio die Bari - Catalogo di prodotti della Ricerca
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La linea d'ombra
No full textl progetto assume la “linea d’ombra” conradiana come metafora del passaggio dalla città contemporanea di Palazzolo Acreide alla sua matrice archeologica. Tra la valle dell’Anapo e i rilievi degli Iblei, il centro storico si configura come una massa muraria stratificata che ancora oggi conserva l’impronta delle antiche architetture rupestri. Il Castello e l’insediamento di Akrai emergono come poli fondativi, connessi da un asse ideale che diventa direttrice del progetto. Una grande copertura, intesa come piano di quota comune, ordina uno spazio ipostilo che protegge e misura i resti archeologici, ricostruendo in forma analogica la continuità della cinta muraria medievale. Una torre si innalza come punto di raccordo tra le diverse quote, segnando il paesaggio e offrendo uno sguardo che si apre verso Akrai e sull’intero territorio ibleo, trasformando il percorso in un’esperienza di attraversamento, memoria e riconoscimento del luogo
A Centralized Distribution Network Model for Reducing Economic and Environmental Impact in Healthcare Logistics
No full textRecent studies have shown that logistics costs in healthcare can constitute up to 35% of hospital expenditures, a figure significantly higher than in other industries. This elevated cost is primarily driven by the decentralized structure of healthcare supply chains, which rely on a large number of warehouses to maintain high service levels and ensure rapid response times. Although the presence of numerous warehouses can support superior service delivery, it also contributes to increased warehousing costs and potential inefficiencies. As such, healthcare systems are confronted with a complex trade-off: maintaining a large number of warehouses to optimize service levels or consolidating them to reduce costs. To address this challenge, the present research work aims to develop an analytical model that facilitates the design of a centralized distribution network, ensuring an optimal solution from both economic and environmental perspectives. The proposed model integrates facility location decisions with vehicle routing considerations. Specifically, it enables a comparative analysis of alternative centralized configurations, which vary in terms of vehicle parameters such as cargo capacity and distance constraints. The model was tested through a case study involving the distribution of medical supplies in the Campania Region (Southern Italy). The results demonstrate the model’s capability to identify the most effective logistics strategy for minimizing the economic and environmental impact of medical supply distribution while maintaining high service levels. Additionally, the approach provides valuable insights into how healthcare systems can achieve cost efficiency and sustainability by optimizing their distribution networks, offering a framework for future logistical improvements in healthcare systems worldwide
Beyond Color Extraction: How Pulsed Electric Fields and Sulfites Affect Phenolic and Volatile Compounds of Primitivo Red Wine
Get PDFThe different impact and interaction of pulsed electric field (PEF) treatment and sulfite addition on the color, phenolic compounds, volatile profile, and sensory properties of a Primitivo wine were studied at bottling and after six months of storage. The results show that PEF treatment, promoting the electroporation of grape skin cells and the permeability of cell membranes, accelerated the extraction of anthocyanins and polyphenols only in the initial phase of maceration. After six months in bottles, wines treated only with PEF show lower levels of hydroxycinnamic acids and flavonols, but a significant increase in procyanidins B2, which are important for structure and color stability and a richer flavor profile, with higher concentrations of fruity esters and higher alcohols. The use of SO2 improves anthocyanin stabilization and facilitates the extraction of polyphenols. The wines from the PEF + SO2 combination maintain greater aromatic freshness, limiting the formation of oxidative compounds. Wines made from SO2 have a more balanced profile, with cherry, plum, and licorice aromas, although the combined PEF + SO2 treatment better preserves fresh fruit aromas, reducing the perception of dried fruits and herbaceous notes
A Safety Aware Deep Reinforcement Learning Technique for Automated Insulin Delivery
No full textAutomated Insulin Delivery (AID) systems have shown great promise in managing diabetes by automating insulin administration. However, a significant challenge remains: preventing hypoglycemia or hyperglycemia during dynamic glucose fluctuations while minimizing the daily insulin dosage, or control effort. This study explores ways to enhance AID systems using a Reinforcement Learning (RL) algorithm called Maskable Proximal Policy Optimization (Maskable PPO), based on invalid action masking. Our findings demonstrate that this approach leads to a safety-aware framework for AIDs, providing highly realistic simulation scenarios for individual adult, adolescent, and child patients. The results show improved Time In Range (TIR) metrics (96.39%, 96.85%, and 54.43%), prevention of emergency bolus administration in adolescent and adult patients, and a reduction in Total Injected Insulin (TII) (17.32 U, 13.52 U, and 4.35 U per day)
Thermal fluctuations effects on crack nucleation and propagation
No full textThis paper investigates the impact of thermal effects on fracture propagation, a subject that poses significant theoretical and experimental challenges across multiple scales. While previous experimental and numerical studies have explored the relationship between temperature fluctuations and mechanical behavior, a comprehensive theoretical framework in fracture mechanics that rigorously incorporates temperature effects is still absent. Building upon the Griffith energetic approach and equilibrium statistical mechanics, we incorporate entropic effects into the overall energy balance of the system and replace the total mechanical energy with free energies. Indeed, our model captures the energetic interplay between elastic deformation, external loads, fracture energy, and entropic contributions. We propose a simplified approach in which both discrete and continuum representations are formulated concurrently, reflecting a multiscale paradigm. The discrete model leverages statistical mechanics to account for temperature effects, while the continuum model provides a mesoscopic description of the fracture process. This framework provides (temperature dependent) analytical expressions for key mechanical parameters, such as the stress and displacement fracture thresholds, the energy release rate, the fracture surface energy, and the J-integral. Notably, we identify a critical temperature at which the system undergoes a phase transition from an intact to a fractured state in the absence of mechanical loading. We believe that this approach lays the foundation for a new theoretical framework, enabling a rigorous multiscale understanding of thermal fluctuations in fracture mechanics. We finally propose a comparison with numerical data concerning the fracture of graphene as a function of temperature exhibiting the efficiency of the model in describing thermal effects in fracture behavior
Synthesis and characterization of succinylated pectin hydrogels with enhanced swelling performances
No full textA novel polymeric material was obtained through succinylation of pectin (S-Pec), resulting in greater stability, film-forming ability, transparency, swelling, and water retention capacity compared to native pectin (Pec). Spectroscopic techniques confirmed the success of the succinylation reaction performed on pectin, employing the reaction of galacturonic acid with succinic anhydride as a model reaction under similar experimental conditions. Moreover, fluorinated succinic anhydride was used to gain insight into the succinylation degree by X-ray Photoelectron Spectroscopy, and a different thermal behavior of S-Pec compared to Pec was confirmed through thermoanalytical characterization. Additionally, the effect of cross-linking either Pec or S-Pec in the presence of divalent cations (i.e., calcium or magnesium ions) on water retention capacity and stability was tested. A significant improvement in the ability to absorb and retain water or saline solution was found for magnesium-crosslinked succinylated pectin, while the in vitro hydrogel stability was higher for the calcium-crosslinked one. The obtained polymer represents a promising substrate for the development of natural-based superabsorbent polymers
Finite deformations induce friction hysteresis in normal wavy contacts
No full textSince Hertz's pioneering work in 1882, contact mechanics has traditionally been grounded in linear elasticity, assuming small strains and displacements. However, recent experiments clearly highlighted linear elasticity limitations in accurately predicting the contact behavior of rubbers and elastomers, particularly during frictional slip, which is governed by geometric and material nonlinearity. In this study, we investigate the basic scenario involving normal approach-retraction contact cycles between a wavy rigid indenter and a flat, deformable substrate. Both frictionless and frictional interfacial conditions are examined, considering finite strains, displacements, and nonlinear rheology. We developed a finite element model for this purpose and compared our numerical results with Westergaard's linear theory. Our findings show that, even in frictionless conditions, the contact response is significantly influenced by geometric and material nonlinearity, particularly for wavy indenters with high aspect ratios, where normal-tangential stresses and displacements coupling emerges. More importantly, interfacial friction in nonlinear elasticity leads to contact hysteresis (i.e., frictional energy dissipation) during normal loading–unloading cycles. This behavior cannot be explained in a linear framework; therefore, most of the experiments reporting hysteresis are typically explained invoking other interfacial phenomena (e.g., adhesion, plasticity, or viscoelasticity). Here we present an additional suitable explanation relying on finite strains/displacements with detailed peculiarities, such as vanishing pull-off force. Moreover, we also report an increase of hysteretic losses as for confined systems, stemming from the enhanced normal-tangential nonlinear coupling
A safety assessment planning strategy proposal within the context of sustainable Urban mobility Plans: How to account for Connected and Autonomous vehicles in safety analysis in the SUMP?
No full textIn the context of Sustainable Urban Mobility Plans (SUMP), when road safety assessments are dealt with, different future scenarios are considered weighing the positive impacts of the proposed strategies for improving the transport system and road safety, globally. However, while considering those future scenarios, until now, the chance that Connected and Autonomous Vehicles (CAVs) will be introduced in the market has never been accounted. Neglecting CAVs can provide misleading results in terms of safety assessment. In this study, a general framework about how to include CAVs in SUMP safety assessments is provided. The general framework, which relies on traffic simulations and algorithms to count conflicts, was tested on two-way two-lane rural roads within the Province of Bari (Italy), where a SUMP was recently developed but the possible introduction of AVs has not been accounted, as it is a common practice in SUMP drafting. Results provided by simulations show a dramatic crash reduction when the traffic is made only of CAVs, while more dangerous situations are highlighted in the case of mixed traffic. Therefore, some countermeasures to handle mixed traffic, such as e.g., reserved lanes for CAVs in case of new roads, must be found and provided for stakeholders and practitioners while dealing with planning strategie