This review critically examines hydrogen energy systems, highlighting their capacity to transform the global energy framework and mitigate climate change. Hydrogen showcases a high energy density of 120 MJ/kg, providing a robust alternative to fossil fuels. Adoption at scale could decrease global CO₂ emissions by up to 830 million tonnes annually. Despite its potential, the expansion of hydrogen technology is curtailed by the inefficiency of current electrolysis methods and high production costs. Presently, electrolysis efficiencies range between 60 % and 80 %, with hydrogen production costs around $5 per kilogram. Strategic advancements are necessary to reduce these costs below $2 per kilogram and push efficiencies above 80 %. Additionally, hydrogen storage poses its own challenges, requiring conditions of up to 700 bar or temperatures below -253 °C. These storage conditions necessitate the development of advanced materials and infrastructure improvements. The findings of this study emphasize the need for comprehensive strategic planning and interdisciplinary efforts to maximize hydrogen's role as a sustainable energy source. Enhancing the economic viability and market integration of hydrogen will depend critically on overcoming these technological and infrastructural challenges, supported by robust regulatory frameworks. This comprehensive approach will ensure that hydrogen energy can significantly contribute to a sustainable and low-carbon future.

The thermal management of cylindrical battery packs, widely used in electric vehicles and energy storage systems, is a critical aspect of ensuring their safety, performance, and longevity. As energy densities increase, effective cooling solutions become essential to address the challenges posed by excessive heat generation and uneven temperature distribution. This review has highlighted the promising potential of hybrid nanofluids and phase change materials (PCMs) in advancing thermal management systems for battery packs. Hybrid nanofluids, offering enhanced heat transfer properties, and PCMs, capable of storing and dissipating latent heat, represent a promising synergy for improving thermal management systems. This review provides a comprehensive analysis of the role of hybrid nanofluids and PCM in addressing the thermal challenges of cylindrical battery packs. The paper discusses heat generation mechanisms, the drawbacks of existing cooling methods, and the advantages of integrating these advanced materials into thermal management systems. By identifying research gaps and opportunities, this review offers a pathway for optimizing battery performance and highlights future research directions necessary for scalable and sustainable solutions. According to this review, future research should concentrate on creating hybrid cooling systems that effectively combine active, passive, and hybrid cooling techniques. Additional advancements in computer modeling, nanotechnology, and material science will be crucial to achieving the full potential of these innovative materials and overcoming existing limitations.

To address the complexities of managing networks of unmanned aerial vehicles (UAVs) and Just-in-Time problem solving, this study introduces a cutting-edge multi-objective location-routing optimization model. This model integrates time window constraints, concurrent pick-up and delivery demands, and rechargeable battery functionality, significantly enhancing the efficiency of UAV operations. It reduces battery consumption and transportation costs while optimizing delivery times and reducing operational risks. The model improves the refinement of delivery schedules by accounting for uncertain traffic scenarios, thereby increasing its accuracy and reliability in dynamic environments. Additionally, a Bayesian belief networks approach for risk assessment introduces a new layer to operational risk management. The model’s performance and its trade-offs are demonstrated through advanced data visualizations such as 3D Pareto fronts, pair plots, and network graphs, with validation via the NSGA-II approach confirming its reliability and practical applicability. This research represents a major leap forward in drone routing strategies, focusing on efficiency, adaptability, and risk management in UAV logistics and provides a comprehensive framework that bridges the gap between theoretical exploration and practical application.