This study focuses on enhancing the performance and reliability of piezoelectric bistable vibration energy harvesters. The research systematically classifies and evaluates different design strategies, aiming to maximize power density through strategic stress manipulation. Five designs are selected for optimization using a finite element model and are evaluated based on a proposed performance metric. The study introduces a method for effectively placing piezoelectric material to enhance power density. Experimental validation shows significant performance improvements, with the best design demonstrating a 71% increase in performance over conventional designs. The findings underscore the importance of addressing performance and durability in developing practical energy harvesters.

The thesis titled "Towards Smart Maintenance: The Implementation of Predictive Maintenance in the Railway Industry" focuses on integrating predictive maintenance (PdM) technologies into railway operations, emphasizing freight rail. PdM employs data analytics, machine learning, and IoT-enabled sensors to shift from traditional maintenance approaches to a proactive, data-driven methodology. This transformation promises reduced downtime, optimized resource use, and enhanced system reliability.

The research identifies technical, financial, and organizational challenges as key barriers to PdM adoption, including data standardization, algorithm maturity, high initial investment, and resistance to change. Drawing lessons from industries like aviation and infrastructure, the study highlights phased implementation, regulatory frameworks, and stakeholder collaboration as critical enablers.

Employing tools like Interpretive Structural Modeling and Fuzzy MICMAC, the thesis maps interdependencies among barriers and demonstrates PdM's potential for reducing maintenance costs by up to 47.8% over two decades. It concludes with recommendations for systematic adoption, addressing both technical and managerial factors, to ensure safer and more efficient railway maintenance practices.