Higher Institute on Territorial Systems for Innovation
PORTO@iris (Publications Open Repository TOrino - Politecnico di Torino)Not a member yet
146173 research outputs found
Sort by
Synergistic enhancement of PEM fuel cell performance for heavy-duty applications: PtCo/N-doped carbon catalyst and short-side-chain ionomer integration
Full text linkThis study systematically investigates a synergistic catalyst–ionomer design strategy integrating catalyst architecture, support chemistry, and ionomer structure to enable proton exchange membrane fuel cell (PEMFC) performance relevant to heavy-duty applications. A non-commercial PtCo alloy catalyst supported on nitrogen doped mesoporous carbon (PtCo/MFCS) enhances intrinsic oxygen reduction reaction activity via alloying while promoting ionomer dispersion, proton accessibility, and favorable interfacial interactions through surface nitrogen functionalities. In parallel, a short-side-chain (SSC) PFSA ionomer (Aquivion® D79) is introduced to improve proton conductivity and water retention under low-humidity conditions. In a systematic MEA campaign, PtCo/MFCS delivers over 16× higher mass activity at 0.9 V (537 vs 32 mA mgPt−1) than a commercial Pt/Vulcan catalyst, despite 43% lower Pt loading, supported by higher electrochemically active surface area and improved dispersion. Beyond kinetic gains, the mesoporous nitrogen-doped support enhances mid-to-high current density performance by facilitating oxygen transport and water management. Replacing Nafion® with Aquivion® D79 further sustains performance under partial humidification down to 33% RH, demonstrating that SSC ionomer benefits emerge only when coupled with appropriate support porosity and chemistry. Overall, the results reveal strong catalyst–support–ionomer synergy, enabling robust, balance-of plant-friendly PEMFC operation and offering a credible pathway toward DOE heavy-duty fuel cell targets
Integration of synchronised IR and PIV unsteady measurements on a channel flow
Full text linkEstimating velocity fields in wall-bounded turbulent flows using non-intrusive, wall-based measurements is a crucial challenge with significant implications for fundamental research and engineering applications like flow control. Traditional methods often rely on technically demanding intrusive probes or numerical simulations, which can be difficult to translate to real-world experimental setups. This study introduces a robust, non-intrusive experimental platform that uses infrared thermography with a heated thin-foil sensor to capture high-resolution, time-resolved measurements of unsteady heat transfer on a channel wall. These measurements are synchronized with particle image velocimetry data to enable the simultaneous acquisition of near-wall velocity fields. The methodology addresses key experimental challenges, including a low signal-to-noise ratio and the need for high-frequency acquisition. We demonstrate that the acquired heat transfer fluctuations show strong spatial and temporal coherence with near-wall structures, supporting their use for velocity field estimation. This work establishes a framework for generating reliable, synchronized datasets, paving the way for the development and validation of data-driven velocity field estimators and advanced active flow control strategies under realistic experimental conditions
Colonial Shadows: Heritage, Climate Change, and the Struggle for Resilience in Post- Colonial Africa
No full textColonial practices prioritized short-term economic gains, disrupting ecosystems and worsening climate change. These activities disrupted ecosystems, exacerbated climate change, and left lasting legacies of environmental degradation. French colonial interventions in Africa, such as Casablanca's nouvelle medina and Congo's Maison Tropicale, were framed as adapting to local climates but ultimately reinforced ecological and social inequalities. Climate change threatens local heritage and indigenous knowledge. This chapter examines the intersection of historical injustices and contemporary environmental challenges, exploring how colonial actions have shaped ongoing struggles for sustainability and equity
Robustness evaluation of existing valuable structures The case study of P.L. Nervi autogrill Motta on A4 motorway in Italy
No full textTowards optimal plasma actuator arrays for friction drag reduction
Full text linkAn optimization framework for the design of an array of DBD plasma actuators to be eventually used for friction drag reduction from turbulent flows is presented. To investigate the plasma induced flow and eventually their effect on the incoming flow, high fidelity simulations were performed. The actuators were modeled according to body force distributions well documented in the literature. The aim of the work is to explore how different geometrical and operational parameters of the PA array affect the induced flow. First, in the optimization iterations, laminar flow simulations are carried out in order to recreate a Stokes-like flow, which can compensate for the known drag-enhancing effect caused by the plasma-jets induced downwash. Then, the effect of the optimized configuration forcing is assessed on a turbulent channel flow at Reτ = 250. Eventually, also the effect of the incoming flow on the plasma-induced flow is evaluated
A methodology for boundary condition optimization in 3D-CFD of internal combustion engines
No full textThis study presents a novel computationally efficient methodology for tuning boundary conditions in 3D CFD simulations of internal combustion engines. The objective is to achieve errors below 1% for in-cylinder pressure at spark timing and below 5% for intake mass. The approach employs an iterative procedure which is grounded on thermodynamic principles, applying the laws of thermodynamics based on both numerical and experimental data during the compression phase. A multi-zone convection model is developed to optimize wall temperatures, while intake pressure is adjusted using physics-informed considerations. In order to refine the multi-zone heat transfer coefficients, the method incorporates a hybrid optimization approach that combines simulated annealing with interior point methods. The methodology is tested on a heavy-duty port fuel injection spark-ignition engine fueled by compressed natural gas. The results demonstrate the effectiveness of this methodology in improving the accuracy of CFD simulations for internal combustion engines, providing a robust framework for boundary condition optimization. This allows the number of 3D simulations required for model tuning and calibration to be reduced compared to trial-and-error or DoE approaches, enhancing model predictive capability
Experimental and regulatory approaches for the standardisation of surgical meshes
No full textL'abstract è presente nell'allegato / the abstract is in the attachmen
L'Emergenza Spontanea del Proto-Indoeuropeo in uno Spazio Latente Pentagonale: Geodetiche Iperboliche e Punti di Sella nel Progetto PantaRei IV
No full textIl presente studio espone l'evoluzione del progetto PantaRei verso una comprensione topologica della transizione linguistica attraverso l'uso di Autoencoder. Superando l'interpolazione lineare statica, la metodologia PantaRei IV introduce una triangolazione pentagonale (Greco, Latino, Sanscrito, Ittita, Gotico) all'interno di un manifold a 64 dimensioni.Attraverso l'attivazione sigmoidea dello strato di bottleneck, che agisce come una funzione iperbolica, lo spazio latente viene deformato in una varietà non euclidea in cui i significati seguono percorsi di minima energia (geodetiche). Monitorando la metamorfosi dinamica in 20 passi discreti, si osserva l'emergenza di un punto di sella critico (Passo 10). In questa zona di transizione, il modello non si limita a una media statistica, ma "estrude" spontaneamente radici fonetiche primordiali vicine al Proto-Indoeuropeo (PIE) ricostruito, come la radice \*bhéreti e forme laringali artificiali. I risultati dimostrano che la pressione informativa di un sistema a cinque corpi linguistici costringe la macchina a operare come un acceleratore di particelle filologico, isolando l'invariante strutturale del linguaggio dalla deriva storica
Evaluating Smartphone RTK Performance with Low-Cost GNSS Receivers and Correction Services in Traditional and Low-Cost GNSS Networks
No full textThe emergence of low-cost GNSS hardware and affordable RTK correction services has made high-precision positioning more accessible. While prior studies have investigated RTK capabilities using smartphones, most rely on professional geodetic infrastructures. This study shifts the focus toward evaluating smartphone-based RTK positioning within low-cost GNSS networks and comparing the performance against traditional geodetic network setups. The research investigates two main configurations: (1) a smartphone functioning as an RTK rover within a low-cost GNSS network, using a low-cost base station and publicly available or inexpensive correction services, and (2) the same smartphone setup operating within a traditional geodetic network with high-grade base stations. The study aims to assess the viability of smartphones as RTK rovers in low cost networks, exploring metrics such as horizontal and vertical positioning accuracy, fix reliability, initialization time, and system responsiveness. Preliminary findings suggest that smartphones integrated with low-cost GNSS receivers can deliver sub-meter accuracy under favorable conditions, though some trade-offs are noted when compared with geodetic-grade infrastructure. The study emphasizes the potential of cost-effective RTK configurations for practical applications where high precision is required. By comparing performance across traditional and low-cost network configurations, this research demonstrates the increasing potential of using smartphones and low-cost GNSS systems to make high-precision positioning more accessible