University of Patras

Inconel 718 dominates laser powder bed fusion (PBF-LB/M) builds as the benchmark Ni superalloy for its γ′/γ″ hardenability, weldability, and qualification pedigree, yet its fatigue resistance remains limited by porosity, tensile residual stresses, and microstructural heterogeneity. Hot isostatic pressing (HIP) reduces porosity but induces grain growth and twinning, which degrade fatigue performance. Prior attempts to control grain size using micron-scale carbides often led to reduced ductility. We introduce a powder modification strategy for reused Inconel 718 feedstock by adding 0.6 wt.% micron-sized niobium and titanium carbides. During PBF-LB/M, these carbides dissolve and reprecipitate as nanoscale carbide-nitrides that pin grain boundaries and refine the microstructure during heat treatment. Neutron diffraction measurements reveal a redistribution of residual stresses, linked to interactions between nano-precipitates and the alloy structure. Fatigue life improves by 150–200% in the 10 5 –10 6 cycle regime, with fatigue limits up to 200 MPa higher than wrought or unmodified, additively manufactured (AM) IN718. This approach enables powder reuse while enhancing mechanical performance, offering a scalable route for fatigue-critical components in aerospace and energy sectors. By integrating powder chemistry and process control, this method demonstrates a sustainable strategy for upcycling aged AM powders into high-performance materials. • Powder-level NbC/TiC addition refines grains and suppresses HIP coarsening • Nano carbide–nitrides pin boundaries and redistribute residual stress • Fatigue life improved by 150–200% with +200 MPa fatigue limit • Compatible with existing IN718 reuse and qualification routes • Enables circular powder use and scalable fatigue-critical AM parts

The sustainability of the wine sector depends on primary production practices and on the adaptability of plant material to climate change. This study evaluates the carbon footprint and technical efficiency of four grape varieties in Paionia using an integrated Life Cycle Assessment and Data Envelopment Analysis framework. A cradle-to-gate approach was adopted, with system boundaries extending from input production to harvest, and functional units of kg CO2e/ha to capture input intensity and kg CO2e/kg grape to assess product-level environmental efficiency. The analysis included 82 vineyards, with DEA scores ranging from 0.744 to 1.000; most vineyards operated below the efficiency frontier, and the input-oriented VRS model identified potential input reductions without affecting output. Merlot showed the highest footprint (3794.02 kg CO2e/ha), followed by Assyrtiko (2798.40) and Xinomavro (2784.48), while Roditis had the lowest (1958.07); on a per-kg basis, emissions were 0.340, 0.304, 0.281, and 0.143 kg CO2e/kg respectively. The DEA identified targeted input-saving opportunities, including reduced irrigation needs in white varieties and lower nutrient and plant-protection requirements in red varieties, while the strong performance of Roditis highlights the advantages of locally adapted, low-input plant material for improving efficiency.

AI travel assistants are increasingly designating hotels as “eco”, yet when the evidence is not independently verifiable, these recommendations may serve as persuasive cues or credible decision support. We present a preregistered 2 × 2 between-subject laboratory experiment (n = 63) that manipulates autonomy framing (Recommend vs. Plan) and evidence verifiability (verifiable vs. non-verifiable) in a realistic hotel-booking workflow with a standardized “Verify eco-claim” drawer. Phasic arousal was recorded at recommendation onset (E1) and verification initiation (E3), employing eye-tracking indexed verification behavior (verify clicks, time-to-verify, verification depth) and event-locked galvanic skin response (GSR). Verifiability did not directly speed up or deepen verification (H1 not supported), but verification was common (74.6% clicked Verify). Rather, autonomy influenced checking: Plan slowed verification and altered verification depth. E1 SCR revealed an Evidence × Autonomy interaction, which is consistent with an autonomy-boundary account (H4), rather than credibility stress emerging as a simple evidence main effect at E1 (H2 not supported as stated). Verification served as a repair moment: depending on the availability of diagnostic cues, arousal dynamics from E1 to E3 supported differential “repair” (H3). SCR dynamics explained incremental variance in perceived manipulation/greenwashing concern beyond condition and eye-tracking indices (H5b supported), but verification depth did not mediate effects on trust or delegation (H5a not supported). Overall, users’ interpretation of AI sustainability advice is influenced by autonomy, and multimodal process measures offer useful signals for auditing eco-recommendation designs in travel platforms.

Colloidal quantum dot (QD) solid-state films are fundamental building blocks for modern optoelectronic devices. In these films, the complex dielectric environment formed by surrounding QDs and organic ligands significantly modifies their electronic and excitonic properties, posing a considerable theoretical challenge. Herein, we report a robust first-principles scheme capable of accurately predicting the fundamental and optical gaps of these films. The methodology's success is rooted in a twofold innovation: the development of optimized, dimensionally consistent Gaussian basis sets that accurately treat both extended and confined systems, and a unique density functional parameterization. This parameterization employs screened range-separated hybrid density functional theory, uniquely incorporating the QD size-dependence of the range-separation parameter while introducing the solid-state film's scalar dielectric constant. This comprehensive scheme determines the electronic structure with an accuracy competing with state-of-the-art self-consistent GW calculations. Applying it to group IV and II-VI QD solid-state films, we achieve an excellent reproduction of experimental fundamental and optical gaps, allowing the accurate determination of the exciton binding energy. We established that this binding energy in solid-state films scales linearly with the inverse QD diameter, a key relationship predicted by classical electrostatics that is largely independent of the material type. Conventional hybrid functional calculations are found to severely fail to quantify this energy and its size-dependent scaling relations. This work provides a cost-effective and broadly applicable theoretical framework for accurately determining the electronic and optical properties of colloidal QD solid-state films.

Η σημασία της ψηφιακής ασφάλειας στις σχολικές κοινότητες της Α’θμιας εκπαίδευσης είναι ιδιαίτερης σημασίας δε δεδομένο πως εκπαιδευτικοί και γονείς φέρουν την κύρια ευθύνη για τη διαμόρφωση συνηθειών ασφαλούς χρήσης των μέσων στους νεαρούς χρήστες. Σκοπός της παρούσας έρευνας είναι να συζητήσει θέματα Ψηφιακής ασφάλειας κατά την Επείγουσα από Απόσταση Διδασκαλία. 20 Εκπαιδευτικοί, 10 Διευθυντές και 12 Γονείς μαθητών σχολείων Πρωτοβάθμιας Εκπαίδευσης συμμετείχαν σε ημιδομημένες συνεντεύξεις οι ερωτήσεις των οποίων αφορούν θέματα ψηφιακής ασφάλειας, εστιάζοντας σε περιπτώσεις επείγουσας από απόσταση διδασκαλίας. Τα αποτελέσματα έδειξαν ότι όλοι οι συμμετέχοντες, γνωρίζουν για την κατοχή λογαριασμού σε μέσα κοινωνικής δικτύωσης από μαθητές Δημοτικών σχολείων, θεωρούν την ενημέρωση γονέων και κηδεμόνων από το σχολείο για θέματα ψηφιακής ασφάλειας πολλή σημαντική και την αναζητούν, θεωρούν πως αυξάνουν οι κίνδυνοι στο διαδίκτυο κατά τη διάρκεια επείγουσας από απόσταση διδασκαλίας, δεν αισθάνονται πολύ σίγουροι για την ικανότητα στη διαχείριση ψηφιακών κινδύνων από τους ίδιους, εκδηλώνουν την ανάγκη επιμόρφωσης σε θέματα ψηφιακής ασφάλειας, και ζητούν υποστήριξη σε θέματα ψηφιακής ασφάλειας, εστιάζοντας σε περιπτώσεις επείγουσας από απόσταση διδασκαλίας.

This study examines the intercultural competence of Greek primary school teachers and early childhood educators enrolled in the Joint Master’s Program Intercultural Education & Mediation at the University of Patras. Using the Intercultural Development Inventory (IDI), the study assessed both perceived and developmental orientations of intercultural competence. The results reveal a significant gap between teachers’ self-assessed and actual competence, with most participants positioned in a minimization orientation—emphasizing commonalities while overlooking the educational value of cultural differences. Such an orientation limits teachers’ ability to fully engage with diversity, often resulting in superficial approaches to multicultural classrooms. The findings underscore the urgent need for systematic professional development in intercultural competence, diversity education, and critical self-reflection. Within this framework, the practicum of the Master’s program emerges as a key mechanism for transformation: through immersive experiences in schools, NGOs, and community organizations, coupled with structured reflective practices, teachers confront real intercultural challenges and develop adaptability, empathy, and resilience. By bridging theory with practice, the practicum fosters meaningful growth in intercultural mindset, enabling educators to acknowledge their biases, embrace cultural diversity as an asset, and design inclusive learning environments. Overall, the study contributes to the literature on intercultural competence and teacher education, offering insights into the challenges Greek educators face and the role of practicum-based learning in fostering culturally responsive teaching.