Huanxin Lai, Yuying Yan and Keqi Wu
This paper aims to develop a numerical method for analysing the time‐dependent conjugate heat and fluid flows inside and around single bubbles rising in a hot liquid.
Abstract
Purpose
This paper aims to develop a numerical method for analysing the time‐dependent conjugate heat and fluid flows inside and around single bubbles rising in a hot liquid.
Design/methodology/approach
The procedure combines the moving mesh method for flows in time‐dependent geometries and the zoned calculation algorithm for conjugate viscous flows. A moving axisymmetric boundary‐fitted mesh is used to track the deformable gas‐liquid interface, while conjugate flows in both gas and liquid sides are calculated by a two‐block zoned method. The interfacial stresses are employed to calculate the velocity value and to decide the time‐dependent bubble shape simultaneously. Governing equations for the rising velocity and acceleration of the bubble are derived according to the forces acting on the bubble.
Findings
A calculating procedure for time‐dependent conjugate heat and fluid flows inside and around a rising single bubble has been developed. The algorithm has been verified, and can be employed for further analysing heat, mass and momentum transfer phenomena and their relevant mechanisms.
Originality/value
The paper developed a method to obtain high fidelity results for the heat and fluid flow details in the vicinity of a time‐dependent moderately deformable rising bubble; the physically zero‐thickness of a gas‐liquid interface is guaranteed. The governing equations for the time‐dependent rising velocity and acceleration are derived.
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Brad McKenna, Wenjie Cai and Hyunsun Yoon
Research into older adults' use of social media remains limited. Driven by increasing digitalisation in China, the authors focus on Chinese older adults (aged 60–75)’ use of…
Abstract
Purpose
Research into older adults' use of social media remains limited. Driven by increasing digitalisation in China, the authors focus on Chinese older adults (aged 60–75)’ use of WeChat.
Design/methodology/approach
This study used a qualitative interpretive approach and interviewed Chinese older adults to uncover their social practices of WeChat use in everyday life.
Findings
By using social practice theory (SPT), the paper unfolds Chinese older adults' social practices of WeChat use in everyday life and reveals how they adopt and resist the drastic changes in Chinese society.
Originality/value
The study contributes to new understandings of SPT from technology use by emphasising the dynamic characteristics of its three elements. The authors synthesise both adoptions and resistance in SPT and highlight the importance of understanding three elements interdependently within specific contexts, which are conditioned by structure and agency.
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Matthew Tingchi Liu, Li Yan, Ian Phau, Andrea Perez and Min Teah
This study aims to investigate the main and interactive effects of three employee attributes, namely, employee friendliness, helpfulness and respectfulness, on customer…
Abstract
Purpose
This study aims to investigate the main and interactive effects of three employee attributes, namely, employee friendliness, helpfulness and respectfulness, on customer satisfaction in Mainland China.
Design/methodology/approach
A 2 × 2 × 2 between-subjects experimental design enabled an eight-scenario study depicting a service experience manipulated by employee friendliness (high/low), helpfulness (high/low) and respectfulness (high/low).
Findings
It is found that the effect of respectfulness has the strongest impact on customer satisfaction. Customer satisfaction generated by helpfulness is higher when respectfulness is high rather than low, while the interaction between helpfulness and friendliness is not found, even though helpfulness exerts a stronger effect than friendliness on customer satisfaction. Customer satisfaction is also maximized when all three positive interpersonal attributes all jointly presented. Interestingly, the absence of respectfulness tends to trigger a negative effect, while the display of friendliness results in a positive effect.
Research limitations/implications
Beyond the joint positive effects on service outcomes, different interaction patterns reveal that the display of friendliness is desirable and beneficial to enhance interpersonal outcome. However, the communication of respect is crucial, and, as such, managers and employees need to strive for a good balance on how to demonstrate these behaviours in critical moments such as service recovery. The findings from relative and interactive effects of three employee attributes are new in the literature and provide significant theoretical and managerial contributions for both researchers and managers.
Originality/value
This study takes the first step in decoding the cultural meaning of employee attributes through integrating Chinese traditional philosophy, Li (i.e. politeness), into a specific service setting by examining its comparative effects with other attributes.
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The present study provides a comprehensive review of the advancements in five active heating modes for cold-proof clothing as of 2021. It aims to evaluate the current state of…
Abstract
Purpose
The present study provides a comprehensive review of the advancements in five active heating modes for cold-proof clothing as of 2021. It aims to evaluate the current state of research for each heating mode and identify their limitations. Further, the study provides insights into the optimization of intelligent temperature control algorithms and design considerations for intelligent cold-proof clothing.
Design/methodology/approach
This article presents a classification of active heating systems based on five different heating principles: electric heating system, solar heating system, phase-change material (PCM) heating system, chemical heating system and fluid/air heating system. The systems are analyzed and evaluated in terms of heating principle, research advancement, scientific challenges and application potential in the field of cold-proof clothing.
Findings
The rational utilization of active heating modes enhances the thermal efficiency of cold-proof clothing, resulting in enhanced cold-resistance and reduced volume and weight. Despite progress in the development of the five prevalent heating modes, particularly with regard to the improvement and advancement of heating materials, the current integration of heating systems with cold-proof clothing is limited to the torso and limbs, lacking consideration of the thermal physiological requirements of the human body. Additionally, the heating modes of each system tend to be uniform and lack differentiation to meet the varying cold protection needs of various body parts.
Research limitations/implications
The effective application of multiple heating modes helps the human body to maintain a constant body temperature and thermal equilibrium in a cold environment. The research of heating mode is the basis for realizing the temperature control of cold-proof clothing and provides an effective guarantee for the future development of the intelligent algorithms for temperature control of non-uniform heating of body segments.
Practical implications
The integration of multiple heating modes ensures the maintenance of a constant body temperature and thermal balance for the wearer in cold environments. The research of heating modes forms the foundation for the temperature regulation of cold-proof clothing and lays the groundwork for the development of intelligent algorithms for non-uniform heating control of different body segments.
Originality/value
The present article systematically reviews five active heating modes suitable for use in cold-proof clothing and offers guidance for the selection of heating systems in future smart cold-proof clothing. Furthermore, the findings of this research provide a basis for future research on non-uniform heating modes that are aligned with the thermal physiological needs of the human body, thus contributing to the development of cold-proof clothing that is better suited to meet the thermal needs of the human body.