Gheorghe Daniel Lakatos

This paper presents a critical review of surface protection strategies for refurbished hydropower components, with emphasis on the manufacturing and materials-processing logic that links damage mechanisms, substrate condition, deposition route, microstructure, and service performance. The literature indicates that cavitation erosion, sediment abrasion, corrosion, and their synergistic interactions are intensified by flexible and off-design hydropower operation, making refurbishment decisions increasingly surface-sensitive rather than purely bulk-material problems. Thermal spray and laser cladding remain the dominant industrially relevant routes, while cold spray and emerging multi-principal-element, high-entropy, and Fe-based amorphous systems expand the design space for lower heat input, better defect control, and improved cavitation resistance. Across the considered studies, the most consistent conclusion is that hardness alone is not a reliable selection criterion; porosity, interfacial integrity, crack susceptibility, residual stress, and the ability to accommodate local deformation govern real durability. Chemical pre-treatments, sealants, and hybrid finishing routes appear less mature as standalone hydropower solutions, but are important enablers for substrate activation, coating densification, and corrosion mitigation. Therefore, the review proposes a refurbishment-oriented framework in which route selection is based on the initial damage state of the component, the admissible thermal load on the substrate, the required build-up thickness, and the expected cavitation/slurry/corrosion regime.

Hydropower plants remain strategic assets for grid stability and decarbonization, with hydraulic turbines governing conversion efficiency, reliability, and environmental performance. This systematic review synthesizes recent methodologies for evaluating and optimizing turbine operation and maintenance to enhance efficiency, reduce impacts, and extend service life. Following a PRISMA-aligned protocol, studies published between 2020 and 2025 were screened across Web of Science and Scopus, using predefined eligibility criteria and a two-stage selection process. The resulting evidence was thematically analyzed across three domains: lifecycle and circular-economy-oriented refurbishment strategies; digitalization and predictive maintenance approaches; and environmentally optimized operating regimes. Of the 115 screened records, 37 met the inclusion criteria. Findings indicate that predictive monitoring, data-driven maintenance, and turbine selection tailored to local hydrology can significantly improve energy performance while reducing operation and maintenance costs. The literature also highlights the importance of ecological flow compliance and reduced aquatic impacts. Complementary case studies from Nepal, Switzerland, Germany, Portugal, and Romania illustrate regional challenges and modernization pathways. Overall, the review underscores the need for integrated, multi-objective turbine management that aligns techno-economic, lifecycle, and ecological considerations to support hydropower competitiveness within the energy transition.

This study is the result of the need to research the visualization of brainwaves. The aim is based on the idea of using generative AI art systems as a method. Data visualization is an important part of understanding the evolution of the world around us. It offers the ability to see a representation that goes beyond numbers. Generative AI systems have gained the possibility of helping the process of visualizing data in new ways. This specific process includes real-time-generated artistic renderings of these data. This real-time rendering falls into the field of brainwave visualization, with the help of the EEG (electroencephalogram), which can serve here as input data for Generative AI systems. The brainwave measurement technology as a form of input to real-time generative AI systems represents a novel intersection of neuroscience and art in the field of neurofeedback art. The main question this paper hopes to address is as follows: How can brainwaves be effectively fed into generative AI art systems, and where can the outcome lead, in terms of progress? EEG data were successfully integrated with generative AI to create interactive art. The installation provided an immersive experience by moving the image with the change in the user’s mental focus, demonstrating the impact of EEG-based art.

This article explores the integration of wood recycling and reuse practices within construction and reconstruction processes, as highlighted in a wood products questionnaire. The aim of this study is to understand how the Romanian consumers perceive the circular economy in order to adopt responsible consumption models. The working instrument consisted of a questionnaire. The questionnaire was applied to 60.7% urban respondents and 39.3% rural ones and consisted of 23 items. The response rate was 68.5% for certain items (257 responses). In the first part, the integration of wood recycling and reuse practices within construction and reconstruction processes is examined. Emerging recycling techniques and demolition processes, particularly incorporating reused, reconditioned, and recycled wood in the construction industry, are evaluated. The economic and environmental implications of these practices are also examined, contributing to the discussion of eco-design policies, and construction waste management and standards. In the second part, insights are provided into how Romanian consumers’ knowledge of CE principles, information about product characteristics, and attitudes influence the demand for recycled wood products. The study concludes with recommendations for better promotion strategies of wood-based recycled products, aiming to increase awareness of its long-term environmental and socio-economic benefits. Additionally, it suggests the need for providing more information on the environmental benefits of wood-based recycled products, and for a more active engagement of stakeholders in the transition to a circular economy. The results serve as a basis for a better understanding of Romanian consumers’ adoption of sustainable consumption behavior in agreement with circular economy concepts and SDGs. While the majority of respondents generally shows openness to an eco-friendly product, mere promotion of these principles may not suffice to change entrenched behaviors and purchasing habits.

Elena Simina Lakatos E-mail: simina.lakatos@ircem.ro Doctor, Institute for Research in Circular Economy and Environment "Ernest Lupan" Cluj-Napoca, Romania https://orcid.org/0000-0003-0096-4494 Sorin Dan Clinci E-mail: dan.clinci@ircem.ro Architect, Institute for Research in Circular Economy and Environment "Ernest Lupan" Cluj-Napoca, Romania https://orcid.org/0000-0001-5310-6376 Viktor Koval E-mail: victor-koval@ukr.net Professor, Southern Scientific Center of National Academy of Sciences of Ukraine and Ministry of Education a nd Science of Ukraine, National Academy of Sciences of Ukraine Kyiv, Ukraine https://orcid.org/0000-0003-2562-4373 Gheorghe Daniel Lakatos E-mail: daniel.lakatos@ircem.ro Doctor, Institute for Research in Circular E conomy and Environment "Ernest Lupan" Cluj-Napoca, Romania https://orcid.org/0000-0002-3280-9061 Urban landscapes are undergoing a transformative phase as they navigate the transition to resilient, circular cities. Cities, inherently complex systems, necessitate sustainable and resilient strategies to address multifaceted challenges. A prominent solution emerges in the form of the Circular Economy (CE), which emphasizes prolonging the life cycle of products through sharing, recycling, reusing, and repairing. Historically rooted in industrial ecology, CE's diverse implementations span across countries, from Germany's innovative waste management initiatives to China's developmental paradigms. The potential of CE is profound: it promises GDP growth, significant reductions in carbon dioxide emissions, and a decrease in raw material consumption. As the global population increasingly gravitates towards urban hubs, cities become the epicenters of sustainable change, with places like Amsterdam and Barcelona leading the charge. These "circular cities" epitomize sustainability, resilience, innovation, and growth, offering holistic benefits from minimal raw material consumption to cross-disciplinary innovation. However, the path to achieving circular urban systems isn't devoid of challenges. Striking a delicate balance between rigorous environmental mandates and urban comfort remains a primary concern. For the seamless integration of CE, a collective approach is crucial, involving policymakers, researchers, and the general public. This paper delves into the intricacies of the CE, its implications, challenges, and the potential roadmap towards resilient urban futures.