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The purpose of this paper is to study the anodic dissolution processes of alloy 690 in NaCl + Na₂S₂O₃ solutions by using digital holography.

The digital holography technique was used to in situ observe the dynamic processes occurring at the electrode|electrolyte interface during the anodic dissolution of alloy 690 in NaCl + Na₂S₂O₃ solutions, both in the presence and absence of a magnetic field (MF).

In 3.5% NaCl + 0.01 M Na₂S₂O₃ solutions, MF inhibited intergranular corrosion (IGC) because it increased the defects in the oxide film and facilitated the uniform adsorption of low concentration of S on these defects due to its stirring effects, which resulted in a weakened adsorption of S at the grain boundaries. Conversely, in 3.5% NaCl + 0.1 M Na₂S₂O₃ solutions, MF promoted IGC by increasing the number of defects in the oxide film, with lots of S species preferentially adsorbing at the grain boundaries. The resultant salt films formed more readily, inhibiting the formation of the oxide film at the grain boundaries.

Through the use of digital holography, it was possible to in situ observe the initiation of IGC at a single grain boundary and its progression to adjacent grain boundaries, regardless of the presence or absence of MF.

With respect to severe working conditions such as heavy load and impact, this paper aims to investigate the friction reduction and anti-wear performance of kaolin and molybdenum dialkyl dithiophosphate (MoDDP) composite lubricant additives to improve the lubrication effect of a single additive.

A four-ball friction test was carried out to determine the optimal concentration of kaolin and organic molybdenum additives and the tribological properties of the kaolin/MoDDP composite lubricant additives. A ring block test of composite lubricant additives was designed to investigate its lubrication performance under the severe working conditions of low speed, heavy load and impact.

The results showed that the optimal addition mass fractions of kaolin and MoDDP were 4.0 and 1.5 Wt.%, respectively, when kaolin and MoDDP were used as single lubricant additives. Compared with the single additive, the 4.0 Wt.% kaolin/1.5 Wt.% MoDDP composite lubricant additive showed excellent friction reduction and anti-wear effects under heavy load and impact conditions. Physicochemical analysis of the wear surface revealed that the lamellar kaolin additive and MoDDP had excellent synergistic effects, and the friction process promoted the generation of lubricant films containing a chemically reactive layer of MoS₂, MoO₂, FeS₂ and Fe₂O₃ and a physically adsorbent layer containing SiO₂ and Al₂O₃, which play important roles in anti-wear and friction reduction.

The excellent friction reduction and anti-wear effects of lamellar silicate minerals and the excellent antioxidant properties and good synergistic effects of molybdenum were comprehensively used to develop the composite additives with great lubricating properties.

Professional social networking sites (SNS) are widely employed by business individuals to build formal relationships, career opportunities, and professional development. While the characteristics of professional SNS are generally different from other SNS, there is limited understanding of the determinants of users’ continued usage on this platform. The study addresses this research gap by developing a conceptual framework that relates perceived values perspective (utilitarian value, hedonic value) and sociability dimensions (social presence, social benefit, social support, and self-presentation) to continuance intention to use professional SNS. Data were gathered from a questionnaire distributed on LinkedIn and analyzed using PLS-SEM. The findings contribute to the emerging literature on the IS continuance domain, particularly in the area of professional SNS. Furthermore, the study can help professional SNS providers properly manage to retain existing users for sustainable business performance.

The purpose of this paper is to develop a coupled lattice Boltzmann model for the simulation of the freezing process in unsaturated porous media.

In the developed model, the porous structure with complexity and disorder was generated by using a stochastic growth method, and then the Shan-Chen multiphase model and enthalpy-based phase change model were coupled by introducing a freezing interface force to describe the variation of phase interface. The pore size of porous media in freezing process was considered as an influential factor to phase transition temperature, and the variation of the interfacial force formed with phase change on the interface was described.

The larger porosity (0.2 and 0.8) will enlarge the unfrozen area from 42 mm to 70 mm, and the rest space of porous medium was occupied by the solid particles. The larger specific surface area (0.168 and 0.315) has a more fluctuated volume fraction distribution.

The concept of interfacial force was first introduced in the solid–liquid phase transition to describe the freezing process of frozen soil, enabling the formulation of a distribution equation based on enthalpy to depict the changes in the water film. The increased interfacial force serves to diminish ice formation and effectively absorb air during the freezing process. A greater surface area enhances the ability to counteract liquid migration.

The precast concrete slab track (PST) has advantages of fewer maintenance frequencies, better smooth rides and structural stability, which has been widely applied in urban rail transit. Precise positioning of precast concrete slab (PCS) is vital for keeping the initial track regularity. However, the cast-in-place process of the self-compacting concrete (SCC) filling layer generally causes a large deformation of PCS due to the water-hammer effect of flowing SCC, even cracking of PCS. Currently, the buoyancy characteristic and influencing factors of PCS during the SCC casting process have not been thoroughly studied in urban rail transit.

In this work, a Computational Fluid Dynamics (CFD) model is established to calculate the buoyancy of PCS caused by the flowing SCC. The main influencing factors, including the inlet speed and flowability of SCC, have been analyzed and discussed. A new structural optimization scheme has been proposed for PST to reduce the buoyancy caused by the flowing SCC.

The simulation and field test results showed that the buoyancy and deformation of PCS decreased obviously after adopting the new scheme.

The findings of this study can provide guidance for the control of the deformation of PCS during the SCC construction process.

This research paper investigates the efficacy of artificial intelligence (AI)-powered Chatbot's in enhancing user engagement and satisfaction within various contexts. As organizations increasingly deploy Chatbot's to interact with users, understanding their impact on user experience becomes imperative. The study employs Smart partial least squares (PLS) as a robust analytical tool to assess the multifaceted dimensions of AI-powered Chatbot interactions. The research focuses on user engagement, examining the Chatbot's ability to captivate users and sustain their interest throughout interactions. Additionally, user satisfaction is explored to gauge the overall effectiveness of the Chatbot in meeting user expectations. The proposed model integrates key variables, including the Chatbot's responsiveness, conversational abilities, and problem-solving capabilities, to comprehensively evaluate its impact. The methodology involves collecting data from diverse user groups to ensure a representative sample. Smart PLS, a powerful structural equation modeling technique, is employed to analyze the relationships between the identified variables. The findings are expected to contribute valuable insights into the factors influencing user engagement and satisfaction in the context of AI-powered Chatbots. The implications of this research extend beyond theoretical understanding, offering practical recommendations for organizations seeking to optimize their Chatbot implementations. By leveraging Smart PLS, this study aims to provide a nuanced understanding of the intricate dynamics involved in AI-powered Chatbot interactions, ultimately guiding the development and deployment of more effective and user-centric conversational agents.

The landscape of health information acquisition has shifted from offline to online, and online question-and-answer (Q&A) communities have emerged as prominent sources of health information; however, it is unclear how users identify satisfactory health information. This paper identifies factors that influence users’ adoption of health information in the context of online Q&A communities.

Based on the elaboration likelihood model (ELM) and opinion leader theory, we construct a research model to examine how information quality (complexity, image structure and emotional change) and source credibility (authentication status, follower number) affect health information adoption behavior. We verify the hypotheses by Poisson regression and zero-inflation Poisson regression using the data collected from an online Q&A community.

The empirical results indicate that both information quality and source credibility positively affect users’ adoption of health information.

This research can assist designers and managers of online Q&A communities to better comprehend users’ health information needs and their preferences for adoption. This enhanced understanding can facilitate the provision of superior online health information.

This research aims to investigate the trajectory tracking problem for a four-wheel independent drive autonomous vehicle (4WID) and propose an integrated, coordinated control strategy to address the mutual interference between trajectory tracking and stability control in extreme cases.

The authors establish an adaptive preview model that modifies the preview distance based on vehicle speed. They utilize a three-degrees-of-freedom vehicle model and employ model predictive control to calculate the necessary front wheel angle for trajectory tracking. In terms of longitudinal control, a longitudinal coordinated control mechanism is established to achieve the two conflicting objectives of trajectory tracking accuracy and dynamic stability through early deceleration. A stability controller based on sliding mode control (SMC) is designed, considering tire constraints and tracking the optimal yaw angle and sideslip angle. Furthermore, a lateral coordinated control strategy is developed, considering the weight coefficient of stability control, and the yaw moment is calculated and distributed based on the vehicle torque requirements.

The proposed integrated, coordinated control strategy successfully addresses the mutual interference between trajectory tracking and stability control in extreme cases for the 4WID vehicle. The strategy achieves trajectory tracking accuracy, dynamic stability and reduced energy consumption while taking into account tire constraints.

We have proposed a cooperative control strategy for the trajectory tracking problem of autonomous driving vehicles. This strategy is different from previous methods in that we have taken into account the integrated dynamic control in both longitudinal and lateral directions, balancing the conflicting control requirements and reducing energy consumption, improving trajectory tracking accuracy and vehicle dynamic stability. We have verified the feasibility of this strategy through joint simulation under different driving conditions.

In this chapter, we describe the importance of good governance in the metaverse. It offers unlimited opportunities and presents unique governance challenges. First, we describe the concept of good governance and its relevance to the metaverse. We emphasize that the speed of metaverse adoption depends upon the presence or absence of effective governance. Recognizing the metaverse as the next iteration of the internet, we present significant governance issues. Some issues such as interoperability, security, safety, privacy, law, and digital inequality are critical governance issues in the metaverse. Next, we explore the diverse governance frameworks to ensure the implementation of policies and regulations. These frameworks include decentralized governance, cross-sector collaboration, and standards-based governance. We also describe the best practices which are essential for good governance. To materialize the concepts and principles discussed, we present a compelling case study centered on Decentraland. This insightful exploration dissects a decentralized autonomous organization (DAO)-based governance structure, offering valuable insights into the intricacies and stages of governance proposals. We acknowledge both the merits and potential drawbacks inherent to this approach. This chapter aims to offer an all-encompassing view of metaverse governance, essentially serving as a comprehensive roadmap for traversing the multifaceted landscape of this digital frontier.

Sustainable tourism practices are the need of the hour not only for the survival of the tourism products but also to make these resources available for future generation. For the generation of meaningful experience, various techniques were administered. This study explores the relationship between meaningful travel and sustainable tourism practices, highlighting how community involvement, environmental protection and cultural preservation are interconnected. The collaboration between decision-makers, destination managers, tour operators and tourists plays an important role in deciding the direction of sustainable tourism. This chapter is based on three objectives. The first objective showcases the global trends in sustainable tourism, the second objective will focus on the elements responsible for meaningful travel and the third objective highlights the suggestions and recommendations for tourism stakeholders. To conduct this study, Scopus-indexed papers were reviewed to identify the factors to achieve the objectives.