In the field of oscillating hydrofoil research, the choice of hydrofoils is still mainly based on traditional NACA airfoils. The article explores the hydrodynamic characteristics of other airfoil structures to further improve the applicable range of hydrofoil working environments. By applying the swept structure of fish tail fins through biomimetic methods to oscillating hydrofoils, a motion model of the swept oscillating hydrofoil is established, and the relevant mathematical expressions and parameter definitions are described. Through numerical simulation methods, the effects of the pitch axis position and the tip-to-root ratio on the performance of the swept oscillating hydrofoil are analyzed. The simulation results show that the pitch axis position has a significant impact on the various force characteristics and energy acquisition efficiency of the hydrofoil, while the tip-to-root ratio mainly reflects the degree of sweep of the hydrofoil, thereby affecting the lift-to-drag ratio and the moment coefficient of the swept hydrofoil. Selecting the appropriate pitch axis position and tip-to-root ratio will enhance the lift of the hydrofoil while reducing the drag experienced.

In response to the escalating demands of global trade and the pressing imperative for environmental preservation, the shipping industry is confronted with the dual challenges of augmenting energy efficiency and significantly curtailing carbon emissions. Ship drag reduction technology emerges as a promising solution to address these critical issues. Over the recent years, a spectrum of diverse drag reduction technologies has been developed, each precisely targeting distinct components of ship resistance and influenced by a multitude of factors. We provide a comprehensive synthesis and critical evaluation of the existing literature on ship drag reduction technologies. It categorizes these technologies into four primary domains: body-attached drag reduction, surface drag reduction, air lubrication drag reduction, and other specialized drag reduction techniques. By presenting detailed and extensive experimental data, coupled with real-world application cases, we underscore the practical implementation and proven efficacy of these technologies in reducing ship drag. We delve into the current limitations and challenges encountered by these technologies. We also offer strategic recommendations for future research endeavors and practical applications, aiming to overcome these limitations and enhance the overall performance of drag reduction technologies. The insights provided in this paper aim to serve as a guide for ongoing efforts in developing innovative and effective utilization of ship drag reduction technologies, ultimately contributing to the sustainability and efficiency of the shipping industry.

This study explores the innovative utilization of a biomimetic electric ray friction nanogenerator (ER-TENG) in combination with electrolysis technology for the remediation of maritime effluent. The ER-TENG is ingeniously crafted with a flexible, planar structure, enabling seamless adaptation to various curved and irregular substrates such as rocks, corals, and shipwrecks on the ocean floor, obviating the necessity for specialized mounting or securing devices. Simulation results regarding the potential distribution between the copper electrode and the PDMS film under different inter-electrode distances indicate that an increase in separation distance is correlated with an enhanced potential difference on the material's surface, exhibiting a linear upward trend, with the maximum potential difference reaching 120 V. When TiO2 nanoparticles are incorporated at a doping mass fraction of 4.65 wt%, the friction nanogenerator attains its peak electrical performance, boasting a peak opencircuit voltage of 123.25 V and a maximum short-circuit current of 13.52 μA, representing increases of 2.73-fold and 2.56-fold in open-circuit voltage and short-circuit current, respectively. At operational frequencies of 1.2 Hz and 1.0 Hz, the initial stage of sterilization rate enhancement proceeds at a moderate pace. However, after 60 minutes of electrolysis, sterilization rates reach 88.12% and 46.36%, respectively. The electrical energy harvested by the ER-TENG facilitates the generation of potent oxidizing chlorine through electrolysis, which effectively eliminates harmful aquatic organisms and pathogens present in ship ballast water.

Sustainable development is a critical global priority, as showed by United Nations' Sustainable Development Goals (SDGs). Effective logistics are crucial for achieving several SDGs so that improvements in Logistics Performance Index (LPI) often align with progress in SDG scores. For ASEAN countries, they may fall short of achieving 90% of their targeted SDGs and struggle to challenges of LPI fluctuations. By calculating the correlation between LPI and SDG scores in R software, this study seeks to explore the relationship between logistics performance and progress toward the SDGs in ASEAN countries from 64 secondary observations. As a result, the increasing logistics performance can greatly impact on the population well-being, accessibility, new energy approach, infrastructure formation, and sustainable production and consumption (G1, G3, G7, G9, G12) in ASEAN countries. The study contributes a background for national policymakers in the region to develop the sustainable logistics.

The green supply chain has become a central concern for global businesses, particularly in maritime industries, where sustainable development is pursued as both an economic growth strategy and a means of environmental preservation. This study seeks to identify the key challenges to implementing green supply chain in Vietnam. The Analytical Hierarchy Process (AHP) is employed to assess the significance of various factors, while Fuzzy Structural Modeling (FSM) is used to explore their interrelationships. Five major factors - economic, technological, organizational, governmental, and social - are identified as critical to the implementation of green supply chain. The study highlights that the organizational factor is the most crucial, with customer pressure, particularly regarding environmental standards from export countries, being the most influential sub-factor. The findings provide important insights for developing government policies, offering support to businesses, and guiding investment decisions in green supply chain.

Efficient and safe maritime navigation in complex and congested coastal regions requires advanced route optimization methods that surpass the limitations of traditional shortest-path algorithms. This study applies Deep Q-Network (DQN) and Proximal Policy Optimization (PPO) reinforcement learning (RL) algorithms to generate and refine optimal ship routes in East Asian waters, focusing on passages from Shanghai to Busan and Ulsan to Daesan. Operating within a grid-based representation of the marine environment and considering constraints such as restricted areas and Traffic Separation Schemes (TSS), both DQN and PPO learn policies prioritizing safety and operational efficiency. Comparative analyses with actual vessel routes demonstrate that RL-based methods yield shorter and safer paths. Among these methods, PPO outperforms DQN, providing more stable and coherent routes. Post-processing with the Douglas-Peucker (DP) algorithm further simplifies the paths for practical navigational use. The findings underscore the potential of RL in enhancing navigational safety, reducing travel distance, and advancing autonomous ship navigation technologies.