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During the service period, the offshore wind turbine (OWT) must withstand multiple fluid loads of wind, waves and ocean currents. While the dynamic characteristics of OWT are affected by the coupling effect between the wind turbine structure, foundation, and fluid environment. Therefore, a complete model with geometrical scaling of 1:100 of the NERL-5MW wind turbine was manufactured and a series of model tests were conducted in the integrated Wind Tunnel-Flume-Foundation experimental system. The strain response characteristics of the monopile foundation were studied for the first time while the OWT under real fluid conditions. The strain response characteristics of OWT monopile foundation in the real fluid were studied for the first time. The experimental results revealed that the loading state, load intensity, and OWT operating state have significant effects on the dynamic strain response of the monopile. Under the coupling effect of complex fluid loads, the effect of waves enhances the strain response in the top region of the monopile foundation, which is attributed to the fact that the deformation of the foundation has amplified the effect of wind load acting on the upper part of OWT. Moreover, the dominant role of aerodynamic loads on the dynamic response of the OWT becomes more pronounced as the load intensity increases. Therefore, coupling effect between the influence of aerodynamic loads acting on the top and the impact of the hydrodynamic load acting on the foundation cannot be ignored. • According to the fluid-structure elasticity similarity, the integrated fluid - structure - seabed model test was carried out for the first time, which can provide reference for the subsequent fixed-foundation offshore wind turbine experimental research and the research on the long-term bearing characteristics of offshore wind turbine foundations. Additionally, it can serve as a validation for the integrated numerical simulation method of OWT. • The strain response characteristics of monopile foundation while OWT under aerodynamic load, hydrodynamic load and coupled load are summarized.The effects of load intensity and OWT operating state on the strain response are also revealed. • Research has found that the contribution of wave load to foundation deformation will strengthen the influence of aerodynamic load on OWT, verifying that the dominant role of wind on the dynamic response of OWT is more significant under the action of aerodynamic-hydrodynamic coupled load. [ABSTRACT FROM AUTHOR]

The clean transformation of domestic sewage treatment is essential for addressing the challenges of current rural environmental pollution. Village cadres, as rural leaders, play a crucial role in organizing and coordinating farmers' participation in improving sewage treatment. Although previous studies have highlighted the importance of domestic sewage treatment, research on how rural leaders' qualities influence farmers' sewage treatment practices remains significantly limited. To fill this gap and clarify the relationship between the qualities of village cadres and farmers' participation in domestic sewage treatment, this study focuses on analyzing whether improving the village cadres' quality can lead to enhanced scientific treatment of rural domestic sewage by farmers. Through linear regression analysis of a sample of rural residents in Jiangxi Province, China, this study demonstrates that the improved quality of village cadres positively affects farmers' scientific treatment of domestic wastewater. The study also finds that farmers' trust in village cadres plays a significant role in aiding high-quality leaders to improve farmers' scientific wastewater treatment behaviors. Moreover, compared to farmers in villages without a representative village council system, those in villages with such a system are more likely to be influenced by high-quality village cadres, thereby improving their wastewater treatment practices. Based on these findings, this article offers practical implications for policymakers and researchers aiming to strengthen rural environmental governance and sustainable development efforts. [ABSTRACT FROM AUTHOR]

Swirling flow was introduced into the solar air collector (SAC) with the purpose of thermal performance improvement. Numerical simulation was carried out to analyze the parameters that affect the thermal performance. The internal flow and heat transfer characteristics were compared between the basic and swirling-flow collectors in order to explain their difference in performance. The sensitivity study shows that the parameters of the swirling type, the swirling state and the swirling intensity all have significant influence on thermal performance of SAC. The numerical results show that the active swirling flow can yield better improvement than passive swirling flow. The maximum thermal efficiency growth rate (TEGR) of active swirling flow and passive swirling flow are 23.83% and 16.03%, respectively, compared with the basic model in the calculation. An experimental model was built to verify the effectiveness of swirling flow in thermal performance enhancement of SAC. The TEGR can be increased by up to 13.24% under small flow rate in the experiment. However, the improvement is not significant when the flow state is turbulent and the Reynolds number is high. This paper provides a new idea for the performance improvement of flat-plate solar air collectors. F06C• Thermal performance of solar air collector is improved by introducing swirling flow. F06C• The improvement of active swirling flow is better than the passive one. F06C• There exists optimum swirling intensity for a certain scale collector. F06C• Improvement by swirling flow is sensitive to the flow type, flow state and intensity. [ABSTRACT FROM AUTHOR]

Implementing vegetable traceability systems is complex. Farmers are producers and the first point of traceability. Their intention and behavior related to implementation of vegetable traceability systems directly determine the success or failure of the implementation of those systems. The objective of this study was to identify factors that affect participation behavior in vegetable traceability systems by using a structural equation model and a logistic regression model. Data collected from a 2019 in-person interview survey of vegetable farmers located in Jiangxi province, China were analyzed. Results from the structural equation model showed that perceived usefulness positively affected farmers' participation intentions and their participation intentions positively affected their participation behavior. The impacts of social influence on perceived usefulness were greater than the impacts of traceability system characteristics on perceived usefulness. Facilitating conditions such as equipment resources, knowledge, and skills that farmers have a significant positive impact on the perceived ease of use. Facilitating conditions and perceived usefulness were two key factors influencing participation intention. Results from the logistic regression model showed that gender, age, marital status, cooperative organization membership, and whether the respondents were near a city had a significant impact on participation intention. The conclusions of this study further expanded the current research scope regarding farmers' quality and safety behaviors and revealed the internal decision-making mechanism for farmers' participation behavior regarding vegetable traceability systems. This study has implications for implementing vegetable traceability systems to ensure food safety in China or elsewhere in the world. • This paper expands technology acceptance model. • Social influence had a significant positive impact on facilitating conditions. • Participation intention impacts participation behavior. • Facilitating conditions and perceived usefulness affect participation intention the most. [ABSTRACT FROM AUTHOR]

Rock-socketed single piles are integral components of offshore wind turbine foundations in rock-based sea areas. Traditional numerical models have been employed to analyze the failure modes and lateral interactions between piles and the rock medium. However, these do not simulate the decline in the horizontal bearing capacity due to rock breakage, posing potential safety risks. In this study, the combined finite-discrete element method (FDEM) was used to simulate the deformation process of submarine rock masses transitioning from an intact to a fractured state. A notable innovation in the proposed approach is the consideration of the effects of the rock mass fracture and pile-rock cohesion on the load-bearing behavior of single-pile foundations. The FDEM model was validated through full-scale lateral load tests. The results showed a distinctive sequence in failure mechanisms, with the tensile failure of the rock mass around the pile at significant depths preceding the compression failure. Local failure at the contact interface significantly reduced the horizontal bearing capacity—a phenomenon that is inadequately represented by conventional finite element models. Furthermore, the cohesion element embedding method was introduced and used to simulate the influence of the tensile properties inherent in grouting materials on the failure strength and mode of the pile-rock interface. This study highlighted the importance of considering the nuanced effects of rock failure in the design of horizontally loaded piles. Failure to do so could lead to nonconservative designs and compromise the safety and efficacy of offshore wind turbine foundations. By pushing the boundaries of numerical modeling with the FDEM, the study aims to provide a more accurate and reliable framework for the design and assessment of rock-socketed single piles for offshore wind energy applications. • The effect of rock mass fracture on the pile-rock interaction of an offshore wind turbine is considered for the first time. • The grout strength at the pile-rock interface is effectively simulated by the cohesive element method. • A simplified Domain Decomposition and Bounding Box method is applied to the FDEM and developed to 2D problems. • Rock-socketed foundations for offshore wind turbines have been analyzed for horizontal bearing performance using FDEM. [ABSTRACT FROM AUTHOR]