Wei Wang, Yongyong He, Yang Li, Bin Wei, Yutong Hu and Jianbin Luo
The purpose of this study is to investigate the inner flow field characteristics of groove textures in thrust bearings. Cavitation and vortex are studied simultaneously to enrich…
Abstract
Purpose
The purpose of this study is to investigate the inner flow field characteristics of groove textures in thrust bearings. Cavitation and vortex are studied simultaneously to enrich the theories of surface texture.
Design/methodology/approach
Navier–Stokes equations are solved using computational fluid dynamics. The MIXTURE model is adopted to study the gas–liquid mixture flow under the cavitation condition.
Findings
Re number, the depth ratio as well as the area ratio of the groove texture and the bottom shape are all influencing factors of the inner flow field characteristics. When cavitation region and vortex region occupy the bottom of the groove texture, these do not overlap because of the pressure gradient. The positive pressure gradient in the non-cavitation region introduces nonlinearity into the velocity profiles, which affects the load-carrying capacity and friction.
Originality/value
Cavitation and vortex are studied simultaneously only in this study. The characteristics of the textured thrust bearing can be analyzed and explained with the combined effect of cavitation and vortex.
Details
Keywords
Wei Wang, Yongyong Zhao, Yenchun Jim Wu and Mark Goh
Although MOOCs have become a pervasive online learning model, the problem of high dropout rates still persists. Gathering the reasons for the high dropout rate can help to improve…
Abstract
Purpose
Although MOOCs have become a pervasive online learning model, the problem of high dropout rates still persists. Gathering the reasons for the high dropout rate can help to improve the platform design and management of the MOOCs.
Design/methodology/approach
A total of 74 studies was extracted from the Web of Science and Scopus. Following the PRISMA (Preferred Reporting Items for systematic Reviews and Meta-Analyses) guidelines, the open-source program CiteSpace is employed to review and induce the studies on the antecedents of MOOC dropout.
Findings
The antecedents of the MOOC dropout rate are the psychological, social, personal, course-related, and time factors, and the unexpected hidden cost. Motivation and interaction, which have a decisive impact on the dropout rate of MOOCs, interact with each other. Interaction helps to strengthen the motivation, and appropriate course design enhances the degree of interaction.
Originality/value
From the perspective of a learner, the more knowledge and skills the learners acquire, the more likely they will complete the course. Possessing adequate foundational knowledge is one way to arrest the dropout rate. On the part of the MOOC platform, better course design eases the dropout rate. Further, the course duration and hidden cost in MOOCs contribute to the dropout rate.
Details
Keywords
Xiaolong Yuan, Yongyong Yang, Feng Wang, Qian Ding, Mianlin Deng, Wendian Shi and Xudong Zhao
Drawing upon social information processing theory, this study investigates the correlation between self-serving leadership and employee expediency. It also explores the mediating…
Abstract
Purpose
Drawing upon social information processing theory, this study investigates the correlation between self-serving leadership and employee expediency. It also explores the mediating effect of self-interest motivation and the moderating effect of trait mindfulness.
Design/methodology/approach
A total of 147 part-time MBA students were enlisted to participate in a scenario experiment (Study 1), and 291 valid employee questionnaires were collected through a multiple-time point survey (Study 2). SPSS 23.0, MPLUS 8.0 and PROCESS programs were used to analyze the data and test the hypotheses.
Findings
Study 1 illustrated a positive correlation between self-serving leadership and employee expediency. It also identified self-interest motivation as a mediating factor in the correlation between self-serving leadership and expediency. Study 2 replicated the results obtained in Study 1 and expanded upon them by demonstrating that trait mindfulness moderates the association between self-serving leadership and self-interest motivation. Additionally, trait mindfulness moderates the indirect effect of self-serving leadership on expediency.
Practical implications
This research argues that organizations should take steps to prevent self-serving leadership in order to reduce employee expediency. Furthermore, it is advisable to provide ethics training to employees who exhibit high trait mindfulness, as they show increased sensitivity to self-serving leadership and are more likely to engage in unethical behavior.
Originality/value
This study expands the existing research on the ethical outcomes of self-serving leadership and contributes to a deeper understanding of the negative aspects of trait mindfulness.