Innovative Technologies Center (Greece)

Steels remain among the most widely used structural and engineering materials in modern infrastructure, energy systems, and industrial facilities. Their long-term reliability depends critically on the early detection of corrosion damage and microstructural degradation. This review surveys recent advances in two complementary families of non-destructive evaluation (NDE) methods: magnetic techniques, including magnetic Barkhausen noise (MBN), magnetic flux leakage (MFL), eddy current testing (ECT), and magnetic hysteresis analysis; and electrochemical methods including electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR), scanning vibrating electrode technique (SVET), and electrochemical noise (EN). Recent progress in sensor miniaturization, signal processing algorithms, and multi-technique integration is reviewed. Particular attention is given to the sensitivity of these methods to microstructural changes reported in the literature, including carbide dissolution, phase transformations, temper embrittlement, and sensitization in stainless steels, as well as to the conditions under which such sensitivity has been demonstrated. The potential synergy between magnetic and electrochemical monitoring is discussed as a possible pathway toward more robust, condition-based maintenance frameworks. Challenges related to field deployment, environmental interference, calibration, and data interpretation are identified, and future directions—including machine learning-assisted analysis and multi-physics sensor arrays—are outlined.

This study investigates left-turn safety at urban intersections using surrogate safety measures derived from field video observations. Time-to-Collision (TTC) among motorized traffic and Post-Encroachment Time (PET) among pedestrian and motorized traffic were extracted for left-turn conflicts across five intersection types in Thessaloniki, Greece, and linked to geometric attributes, signal operations, and traffic conditions. Count-based models (Poisson, Negative Binomial) were estimated alongside machine-learning approaches (Random Forest, Gradient Boosting with Poisson loss). For PET events, the Poisson model had the best balance of parsimony and predictive accuracy, whereas the Negative Binomial model provided a superior fit for TTC events. Results indicate that PET-defined conflicts increased with pedestrian volume and the presence of shared and protected left-turn lanes, and decreased with higher opposing flow, greater average acceleration, and wider end-approach lanes. By contrast, TTC events were associated with lower average speeds, the presence of protected signal phasing for left turns, and the number of passenger cars. Machine-learning models underperformed relative to classical count models, reflecting limited sample size and the discrete event structure. The analysis indicates that the determinants of TTC and PET differ, with certain variables such as pedestrian activity and lane configuration having contrasting effects on the two surrogate safety measures. The analysis reveals that pedestrian demand and shared lane configurations significantly increase PET occurrences, whereas TTC events are more strongly associated with vehicle volumes, speeds, and signal phasing. This distinction underscores the importance of tailoring safety assessment and intervention strategies to the type of interaction being evaluated.

This study presents an in situ and laboratory evaluation of an innovative biocide-free nanocomposite coating designed to provide dual anti-corrosion and anti-fouling protection for EH36 naval steel in marine environments. The coating, comprising polyaniline nanorods, titanium dioxide nanoparticles, and Fe3O4-functionalized multiwalled carbon nanotubes embedded in a robust resin matrix, was systematically assessed through electrochemical, microscopic, and field-based methods. Laboratory immersion tests and extended exposures at two Mediterranean sea sites (Thessaloniki and Heraklion) revealed substantial improvements in corrosion resistance and significant suppression of marine biofouling over periods of up to 24 months. Electrochemical measurements demonstrated that coated specimens maintained a corrosion inhibition efficiency exceeding 93% throughout the study, exhibiting markedly lower corrosion current densities and higher charge transfer resistances than uncoated controls. Impedance spectroscopy and equivalent circuit modeling confirmed sustained barrier properties, while digital imaging and qualitative biological assessments showed reduced colonization by both micro- and macrofouling organisms. Comparative analysis with conventional biocidal and alternative eco-friendly coatings underscored the superior durability, environmental compatibility, and anti-fouling efficacy of the developed system. The results highlight the coating’s promise as a sustainable, high-performance solution for long-term protection of naval steels against the combined challenges of corrosion and biofouling in harsh marine settings.

In this paper, we present the development of a framework for the task scheduling system to enable the robotic automation of UHVC (ultra-high voltage center) inspection. Equipment failures at UHVC could be significantly reduced if the inspection methodology allowed for condition-based maintenance (CBM) and the equipment status was systematically monitored. To address this, an autonomous mobile robotic vehicle for inspection using an onboard system of optical and thermal cameras has been developed. The framework enables the automatic determination of the inspection schedule based on a combined time-and condition-criterion, the Total Reliability Index (TRI). The TRI represents the probability of equipment failure based on the evaluation of the images obtained through thermal and optical cameras, as well as the component’s age and frequency of inspection, based on its specifications and its importance in the UHVC infrastructure. Depending on the TRI value, a decision is made as to whether a component should be inspected as part of the regular monthly inspection or if it requires more frequent monitoring. The developed framework allows the automated creation of inspection plans on a monthly and weekly basis, based on each component’s TRI and without requiring the user’s input. The framework also enables the user to create inspection plans that can be saved, modified, and scheduled for immediate or future execution. In all cases, the output of the framework is th e list of elements for inspection. The framework enables the execution of systematic, frequent, automated inspections and will lead to financial, administrative and information benefits.

The main aim of this study is to model the Nature-based solution of Green Roofs (GRs) in order to assess their efficiency as a mitigation strategy for UHI effects and extreme summertime temperatures over Attica in Greece. The area of study is a region that encompasses Athens, the largest Metropolitan area of Greece, and the suburbs. The analysis has been performed with the use of an advanced modeling system that consists of the mesoscale Weather Research and Forecasting model (WRF) and the advanced multilayer urban canopy scheme building energy parameter and building energy model (BEP/BEM). The two modules are fully coupled, forming WRF urban. For a better description of the urban environment and in order to use the full capabilities of the urban canopy scheme, 11 urban classes corresponding to the WUDAPT Local Climate Zones (LCZ) were used instead of the 3 traditional urban classes that the default version uses. Sensitivity tests for a major heatwave that affected the area of study have been performed in order to evaluate the impact of GRs on the UHI structure. Results indicate that the modification of the roof energy budget decreased the maximum temperature during heatwaves and altered the spatio-temporal pattern of the effect.

The use of Nature-based Solutions (NBS), designed and implemented with participatory approaches, is rapidly increasing. Much use is being made of the Living Lab (LL) concept to co-create innovative NBS with stakeholders in a certain societal and environmental, real-life context. Most of the current research revolves around urban LLs, thus overlooking specificities of rural areas. Furthermore, the influence of the context itself on co-creation processes is insufficiently recognised, leaving challenges associated with co-creation such as stakeholder engagement unresolved. By exploring the co-creation processes in the LLs of the OPERANDUM project, this study identifies eighteen contextual factors shaping the co-creation processes of NBS within rural territories and provides associated recommendations. In addition, based on lessons learnt in the OPERANDUM project, we discuss the value of a relational place-based approach in LLs, suggesting that the co-creation process should be approached as a dynamic confluence of many interconnected contextual factors. We conclude that acknowledging the interconnections in co-creation in the real-life context of rural territories may increase the success and impact of the LL approach, and ultimately, the benefits of NBS.

The present paper investigates the stages of the microstructure and texture evolution in non-oriented electrical silicon steels by means of magnetic measurements and metallographic analysis. The goal of this work was to study temperature effects and their influence on grain growth processes in non-oriented electrical steels while being subjected to different annealing conditions and to clarify the mechanism of grain boundary motion during annealing. It is important to study the development of texture and grain size in electrical steel samples along the entire production line chain (hot rolling, cold rolling, and final annealing), as both are affected by each processing stage. The lack of magnetic data dependent on the operating temperature of non-oriented electrical steels makes it impossible to accurately design high-power motors (e.g., propulsion systems in ships) or generators that are to operate at high temperatures. The correlation of magnetic properties with the microstructure of electrical steels can yield important information about their suitability for various substrates and marine applications. In addition, it can potentially non-destructively define both the annealing stage and the preferred crystallographic growth pattern in single-phase ferritic steels, which affect the performance and longevity of the electromagnetic devices in which these are used.

5G Stand Alone (SA) networks are starting to be considered, designed and implemented in multiple countries in various forms (public, private, experimental). 5G SA networks mass adoption is expected to materialize by 2025. Mass deployment is anticipated at a large scale, due to the rich features and capabilities offered by 5G networks, including but not limited to slicing, service orchestration and automation, bringing the benefits of 5G among industry stakeholders and verticals. The concept of Network Applications is gaining momentum, as a way to ease the process of deploying industry-specific services and applications and to integrate them seamlessly with the new 5G networks and customer-specific application components. We target deploying and operating the novel 5G SA testbeds, Network Application and related capabilities in different T&L facilities across Europe. We envision the architectural advancement in terms of 5G features, such as orchestration, multi-slice implementation, Quality of Service (QoS)/Quality of Experience (QoE) and an innovative end-to-end monitoring framework, for network and application KPIs. In this paper, 5G open testbed advancements (3GPP Rel. 16 compliant) and readiness for Network Application experiments in real-life scenarios are presented, integrated as a unitary whole within the EU-funded VITAL-5G project.