This study examines whether green logistics performance (GLI) is associated with national competitiveness (NCI) in a nonlinear manner using a global panel aligned with the World Bank Logistics Performance Index (LPI) survey waves from 2007 to 2023. The dataset covers 136 countries and 663 country–wave observations. Two-way fixed-effects models provide evidence of a U-shaped association: the estimated conditional association is negative at lower levels of green logistics upgrading and changes sign around the turning point of the fitted quadratic. Exploratory turning-point comparisons and cluster-based descriptions suggest that the nonlinear pattern is most visible among countries in transition rather than in the weakest or most advanced logistics regimes. Overall, the findings indicate that the competitiveness payoff of greener logistics is stage-dependent rather than immediate.
The transition to low-emission marine fuels has significantly increased the application of fuel gas supply systems (FGSS) on dual-fuel vessels, introducing new safety challenges associated with cryogenic fuels and gas handling. This paper develops a structured safety concept for an FGSS installed on a 1400 TEU container vessel, aiming to enhance system reliability and minimize operational risks. The proposed concept is based on a risk-oriented and barrier-based approach, incorporating multiple Layers of Protection (LoP) to prevent hazardous events and mitigate their consequences. The study systematically addresses key safety domains, including prevention of containment loss, implementation of controlled gas release strategies, and emergency handling procedures in the event of leakage. Measures for reducing ignition probability and managing fire scenarios are also analyzed, combining both passive and active safety techniques. The arrangement concept of the FGSS is evaluated with respect to hazardous area classification, system segregation, and layout optimization. Engineering design criteria, including design pressures, temperature limits, and material selection, are assessed in relation to cryogenic conditions and mechanical integrity requirements. Particular attention is given to containment and vent systems as critical elements for pressure relief and safe gas dispersion. Furthermore, the integration of safety systems, instrumentation and control architecture, and the fuel gas monitoring system is examined, emphasizing real-time detection, automation, and emergency shutdown capabilities. The results demonstrate that the application of a multi-layered safety framework significantly reduces the likelihood and impact of hazardous events in FGSS operations. The proposed approach provides a practical reference for the design and safety assessment of gas-fueled container vessels in compliance with contemporary regulatory requirements.
