Ka Han, Junning Li, Qian Wang, Wuge Chen and Jiafan Xue
The purpose of this study is to reveal the tribological performance of the textured rolling bearing.
Abstract
Purpose
The purpose of this study is to reveal the tribological performance of the textured rolling bearing.
Design/methodology/approach
In the present study, the oil film pressure distribution and load capacity analysis method are established, which integrate the micro-texture model and Hydrodynamic lubrication (HL) methods. The tribological performances of the textured rolling bearing under the various working condition, texture dimension and texture type are investigated systematically.
Findings
The results show that the oil film load capacity increases with the increase in the texture size. As the texture depth increases, the oil film load capacity increases first and then decreases, and then the load capacity is the largest at the texture depth range of 3 to 5 µm. In addition, the oil film load capacity of the matching pairs, such as Si4N3-Si4N3, GCr15- Si4N3 and GCr15-GCr15 are compared; the results show that the cases of using ceramic material can improve oil film load capacity of textured rolling bearing.
Originality/value
The current manuscript can be useful for supporting the reliability and life research of textured rolling bearing.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2020-0055
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Junning Li, Ka Han, Wuge Chen, Xiaojie Tang and Qian Wang
The purpose of this study is to reveal the lubrication performance of textured roller bearings under various texture size, texture depth, texture types and slip.
Abstract
Purpose
The purpose of this study is to reveal the lubrication performance of textured roller bearings under various texture size, texture depth, texture types and slip.
Design/methodology/approach
In the present study, the improved thermal elastohydrodynamic lubrication method based on the surface texturing of the textured roller bearings is proposed, and then the effect of texture size, texture depth, texture types and slip on the contact pressure, film thickness and temperature distribution are analyzed systematically.
Findings
The results show that the pressure decreases and the film thickness increases on the contact area because of the surface texturing. The temperature increases first and then decreases as the texture size increases, and then the temperature increases as the texture depth and the slip increases. Compared to circle and square texture, cross texture can obviously decrease the temperature on the contact area. The effectiveness of the proposed method is verified.
Originality/value
This study can help to reduce friction and wear of textured roller bearings.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-08-2020-0318/
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Qin Tan, Yali Zhang, Xinle Li, Jian Pu, Shu Yang and Zhongmin Jin
This study aims to systematically investigate the tribological behaviors of metal and polyethylene using lubricants composed of four synovial fluid (SF) components. In addition…
Abstract
Purpose
This study aims to systematically investigate the tribological behaviors of metal and polyethylene using lubricants composed of four synovial fluid (SF) components. In addition, the changes in protein conformation during wear were analyzed to establish the correlation between protein conformation and tribological properties.
Design/methodology/approach
A pin-on-disk tester with multidirectional sliding motion was used for tribological properties observation between metal and polyethylene pairs. Simulated SFs with four main constituents were used as the testing lubricants. Differential scanning calorimetry and Raman were used to characterize the changes in protein conformation during wear.
Findings
The coupling of lipids and hyaluronic acid further suppressed protein denaturation. The protein structures of the adsorption film and the ensnared protein chains in the friction zone were maintained to a certain extent, thus improving the friction and wear of polyethylene.
Originality/value
These findings established the correlation between protein conformation and friction and wear, promoting the understanding of the lubrication mechanism of artificial joints.
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Yansui Liu, Yuanzhi Guo and Yang Zhou
Poverty alleviation is a global challenge. Human society has never ceased to fight against poverty. China was once the developing country with the largest rural poor population in…
Abstract
Purpose
Poverty alleviation is a global challenge. Human society has never ceased to fight against poverty. China was once the developing country with the largest rural poor population in the world. Remarkable achievements have been made in China’s antipoverty program over the past decades, shaping a unique poverty reduction strategy with Chinese characteristics. The purpose of this paper is to first review the history of China’s rural reform and antipoverty, and then analyze the related policy systems, mechanism innovations and future challenges in poverty alleviation and development. At last, some specific policy implications were provided.
Design/methodology/approach
Literature on China’s antipoverty history was reviewed and mechanism innovations on targeted poverty alleviation strategy were investigated.
Findings
Along with the deepening of the rural reform, the poverty alleviation and development in new China have undergone six stages, and experienced a transformation from relief-oriented to development-oriented poverty alleviation. The object of poverty alleviation has gradually targeted with a transformation from poor counties/areas to villages/households, and the effectiveness of poverty alleviation is also gradually improved. However, the increase in the difficulty of antipoverty, fragile ecological environment, rapid population aging and rural decline poses challenges to the construction of a well-off society in an all-round way in China. Specific antipoverty measures were put forward based on the investigation. Finally, the authors emphasize the importance of strengthening the study of poverty geography.
Originality/value
This study investigates the history of China’s antipoverty policy and analyzes the future challenges for implementing targeted poverty alleviation policy. These findings will lay a foundation for the formulation of China’s antipoverty policies after 2020, and provide experience for poverty alleviation in other developing countries around the world.
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To examine “universal service” as a policy objective in post‐WTO accession Chinese telecommunications and analyze the challenges of the Chinese telecommunications system in…
Abstract
Purpose
To examine “universal service” as a policy objective in post‐WTO accession Chinese telecommunications and analyze the challenges of the Chinese telecommunications system in defining and promoting public service ethos in a country that is marked by staggering disparities.
Design/methodology/approach
A range of media, academic, industry, and policy discourses on “universal service” and a broader notion of “public service,” together with recent government efforts in promoting “universal service,” are examined and assessed to develop an analysis of the uneven nature of China's telecommunications development and reveal the dynamics of “universal service” policy formation, as well as the impetuses and impediments in developing any notion of public service telecommunications in China.
Findings
Public service issues in China need to be situated within a continuing process of uneven development which comprises dimensions other than residential telephone access. Although the ultimate policy goal appears to develop a nationally accessible telecommunications infrastructure as the basis of a unified national economy, this overall objective is beset by conflicts and contingent on the dynamics of elite and popular struggles over and beyond telecommunications development. Despite the spectacular expansion in telephone access, pragmatic concessions to dominant power groups, rather than a principled commitment to “universal service,” let alone efforts to define the social functions of telecommunications in more democratic ways, have shaped the development of China's telecommunications.
Originality/value
The development of China's telecommunications infrastructure offers lessons both as to the likelihood of successfully establishing an integrated national economy, and the role of public service in that context. However, the Chinese telecommunications policy field remains extremely fluid.