Articles in Press

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Summary:
The concept of the hydrogen economy has attracted significant attention in recent years due to its potential to revolutionize the way we manage waste and transition towards a more sustainable future. This paper aims to provide a comprehensive overview of the current state of research on the topic of the hydrogen economy, focusing on its application in the waste sector. The study utilizes systematic literature review and bibliometric analysis to identify key factors influencing the success rate of hydrogen economy implementation and to determine the definition of the hydrogen economy in the waste sector. The methodology used involved a combination of Systematic Literature Review (SLR) and Bibliometric Analysis (BA), which enabled detailed analysis of the results and provided a faster analysis of the practical literature than other methods of analysis. The findings of this study highlight the importance of understanding current research trends and gaps in the field, as well as the need for a deeper understanding of the factors that influence effective participation in the hydrogen economy. By reviewing the existing literature and identifying the most prominent research themes, this study aims to contribute to the development of a more comprehensive framework for the implementation of the hydrogen economy in the waste sector, ultimately supporting the transition towards a more sustainable and environmentally friendly model.

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Summary:
Acetylene (C₂H₂) has attracted research interest as a high-reactive fuel for internal combustion engines due to its high flame speed, low ignition energy, and wide flammability limits. When introduced as a supplementary fuel, acetylene can change combustion characteristics, enabling improved thermal efficiency, extended lean operation, and substantial reductions in particulate emissions across spark-ignition (SI), compression-ignition (CI), and advanced combustion concepts. However, these advantages are counterbalanced by pronounced challenges related to abnormal combustion, elevated pressure rise rates, increased NOx emissions, and stringent safety constraints. Drawing from peer-reviewed articles, this study offers a comprehensive synthesis of experimental, numerical, and system-level research on acetylene-fueled engines. The performance, combustion behavior, and emission characteristics of SI, CI, dual-fuel, HCCI, and RCCI setups are systematically compared. The review reveals the limited operational periods in which acetylene can be used efficiently, discusses differences between research, and shows recurring tendencies. When safety, storage, and life-cycle sustainability factors are evaluated, it becomes clear that acetylene's production process, rather than just its in-cylinder advantages, dominates its environmental viability. Acetylene is better positioned as a combustion enhancer in tightly regulated multi-fuel systems rather than as a stand-alone alternative fuel. The research also identifies important research objectives needed for any future practical deployment.

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Summary:
Focusing on vibration-based power generation, this research investigates design changes intended to overcome the drawbacks of conventional wind turbines. To improve aerodynamic performance, the motion characteristics of two different geometries with the same surface area were evaluated. The components were designed in Solidworks and produced via 3D printing. The findings reveal how modifications in the turbine's shape affect its overall efficiency. Notably, the structural characteristics of the PLA and PETG materials used for the prototypes led to a divergence between experimental results and theoretical expectations.