Yanfu Wang, Xin Wang and Lifei Liu
Lapping is a vital flattening process to improve the quality of processed semiconductor wafers such as single-crystal sapphire wafers. This study aims to optimise the lapping…
Abstract
Purpose
Lapping is a vital flattening process to improve the quality of processed semiconductor wafers such as single-crystal sapphire wafers. This study aims to optimise the lapping process of the fixed-abrasive lapping plate of sapphire wafers with good overall performance [i.e. high material removal rate (MRR), small surface roughness (Ra) of the wafers after lapping and small lapping plate wear ratio (η)].
Design/methodology/approach
The influence of process parameters such as lapping time, abrasive size, abrasive concentration, lapping pressure and lapping speed on MRR, Ra and η of lapping-processed sapphire wafers was studied, and the results were combined with experimental data to establish a regression model. The multi-evaluation index optimisation problem was transformed into a single-index optimisation problem via an entropy method and the grey relational analysis (GRA) to comprehensively evaluate the performance of each parameter.
Findings
The results revealed that lapping time, abrasive size, abrasive concentration, lapping pressure and lapping speed had different influence degrees on MRR, Ra and η. Among these parameters, lapping time, lapping speed and abrasive size had the most significant effects on MRR, Ra and η, and the established regression equations predicted the response values of MRR, Ra and η to be 99.56%, 99.51% and 93.88% and the relative errors between the predicted and actual measured values were <12%, respectively. With increased lapping time, MRR, Ra and η gradually decreased. With increased abrasive size, MRR increased nearly linearly, whereas Ra and η initially decreased but subsequently increased. With an increase in abrasive concentration, MRR, Ra and η initially increased but subsequently decreased. With increased lapping pressure, MRR and η increased nearly linearly and continuously, whereas Ra decreased nearly linearly and continuously. With increased lapping speed, Ra initially decreased sharply but subsequently increased gradually, whereas η initially increased sharply but subsequently decreased gradually; however, the change in MRR was not significant. Comparing the optimised results obtained via the analysis of influence law, the parameters optimised via the entropy method and GRA were used to obtain sapphire wafers lapping with an MRR of 4.26 µm/min, Ra of 0.141 µm and η of 25.08, and the lapping effect was significantly improved.
Originality/value
Therefore, GRA can provide new ideas for ultra-precision processing and process optimisation of semiconductor materials such as sapphire wafers.
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Jianbin Luo, Yuanhao Tie, Ke Mi, Yajuan Pan, Lifei Tang, Yuan Li, Hongxiang Xu, Zhonghang Liu, Mingsen Li and Chunmei Jiang
The purpose of this paper is to investigate the optimal average drag coefficient of the Ahmed body for mixed platoon driving under crosswind and no crosswind conditions using the…
Abstract
Purpose
The purpose of this paper is to investigate the optimal average drag coefficient of the Ahmed body for mixed platoon driving under crosswind and no crosswind conditions using the response surface optimization method. This study has extraordinary implications for the planning of future intelligent transportation.
Design/methodology/approach
First, the single vehicle and vehicle platoon models are validated. Second, the configuration with the lowest average drag coefficient under the two conditions is obtained by response surface optimization. At the same time, the aerodynamic characteristics of the mixed platoon driving under different conditions are also analyzed.
Findings
The configuration with the lowest average drag coefficient under no crosswind conditions is 0.3 L for longitudinal spacing and 0.8 W for lateral spacing, with an average drag coefficient of 0.1931. The configuration with the lowest average drag coefficient under crosswind conditions is 10° for yaw angle, 0.25 L for longitudinal spacing, and 0.8 W for lateral spacing, with an average drag coefficient of 0.2251. Compared to the single vehicle, the average drag coefficients for the two conditions are reduced by 25.1% and 41.3%, respectively.
Originality/value
This paper investigates the lowest average drag coefficient for mixed platoon driving under no crosswind and crosswind conditions using a response surface optimization method. The computational fluid dynamics (CFD) results of single vehicle and vehicle platoon are compared and verified with the experimental results to ensure the reliability of this study. The research results provide theoretical reference and guidance for the planning of intelligent transportation.
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Qingyu Shi, Jingyu Yu, Lifei Zhang, Jingfeng Wang and Guowei Cheng
The construction industry has experienced an irreversible digital transformation to smart construction. Many countries have published supporting policies to encourage the…
Abstract
Purpose
The construction industry has experienced an irreversible digital transformation to smart construction. Many countries have published supporting policies to encourage the development of smart construction. However, there is no universally valid approach. This paper thus aims to evaluate smart construction policies issued by 24 pilot cities in China and identify applicable policy tools and their impact.
Design/methodology/approach
This paper collected 33 governmental documents on smart construction through the official websites in China. Different policy tools were classified into supply-side, demand-side and environment-side categories. The supporting policies of smart construction development in pilot cities were quantitatively evaluated by using a policy modeling consistency index (PMC-index) model.
Findings
Supply-type and environment-type policy instruments were used more frequently than demand-type policies in 24 pilot cities. Most of the 24 pilot cities had an evaluation of PMC-index over 8, realizing the consistency of smart construction policies. Eight pilot cities had an evaluation of PMC-index of 6–7.99, realizing acceptable consistency. Only Foshan City has an evaluation of PMC-index below 4, which may reflect a poor consistency of policy implementation. The paper proposes consistencies of smart construction policies of 24 pilot cities and valid policy instruments, including the presale of commercial residential buildings, additional bonus points in the tendering process and cooperating with multiple departments when promoting smart construction.
Originality/value
This paper contributes to expanding policy evaluation studies in the smart construction field and provides concrete suggestions for policymakers to formulate more effective and specific policies and strategies for the development of smart construction.
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Lei Fu, Hui Li, Li Lin, Qingyuan Wang, Qi Fan, Xinjie Huang, XiuLan Li, Sheng Lai and Lifei Chen
Most supersonic aircraft were manufactured using 2A70 aluminum alloy. The purpose of this paper is to study the corrosion mechanism and fatigue behavior of an aircraft in a…
Abstract
Purpose
Most supersonic aircraft were manufactured using 2A70 aluminum alloy. The purpose of this paper is to study the corrosion mechanism and fatigue behavior of an aircraft in a semi-industrial atmospheric corrosive environment, alternating effects of corrosion and fatigue were used to simulate the aircraft’s ground parking corrosion and air flight fatigue.
Design/methodology/approach
For this purpose, the aluminum alloy samples were subjected to pre-corrosion and alternating corrosion-fatigue experiments. The failure mechanisms of corrosion and corrosion fatigue were analyzed using microscopic characterization methods of electrochemical testing, X-ray diffraction and scanning electron microscopy. Miner’s linear cumulative damage rule was used to predict the fatigue life of aluminum alloy and to obtain its safe fatigue life.
Findings
The results showed that the corrosion damage caused by the corrosive environment was gradually connected by pitting pits to form denudation pits along grain boundaries. The deep excavation of chloride ions and the presence of intergranular copper-rich phases result in severe intergranular corrosion morphology. During cyclic loading, alternating hardening and softening occurred. The stress concentration caused by surface pitting pits and denudation pits initiated fatigue cracks at intergranular corrosion products. At the same time, the initiation of multiple fatigue crack sources was caused by the corrosion environment and the morphology of the transient fracture zone was also changed, but the crack propagation rate was not basically affected. The polarization curve and impedance analysis results showed that the corrosion rate increases first, decreases and then increases. Fatigue failure behavior was directly related to micro characteristics such as corrosion pits and microcracks.
Originality/value
In this research, alternating effects of corrosion and fatigue were used to simulate the aircraft’s ground parking corrosion and air flight fatigue. To study the corrosion mechanism and fatigue behavior of an aircraft in a semi-industrial atmospheric corrosive environment, the Miner’s linear cumulative damage rule was used to predict the fatigue life of aluminum alloy and to obtain its safe fatigue life.
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Xi Liu, Bu Mi, Fei Li and Deqiang Zou
This study aims to explore how the ideal employee effects of internal marketing are created and sustained. It aims to reveal the role that outbound marketing activities play in…
Abstract
Purpose
This study aims to explore how the ideal employee effects of internal marketing are created and sustained. It aims to reveal the role that outbound marketing activities play in the reproduction of a brand-centric employee culture.
Design/methodology/approach
From an organizational ritual perspective, this study conducts a qualitative study of a Chinese department store’s anniversary celebration, which is a multi-day annual sales event. Data were collected through in-depth interviews, supplemented with corporate documents and field observation.
Findings
This study reveals that the focal event remains a success because the well-managed coordination of its onstage and backstage activities serves to reproduce an employee culture of espousing and voluntarily enacting corporately mandated role norms, values and beliefs.
Practical implications
For the management of retail events with the aim of building organizational culture, this study points to the importance of emphasizing the symbolism of the sales promotion aspects of an event and paying as much attention to employees’ backstage experiences as to the public execution of a consumer event.
Originality/value
This study shows that external marketing could set the stage for internal marketing, with the ideal effects of internal marketing actually constructed and institutionalized during activities and procedures comprising outbound marketing. This suggests that a more nuanced view of the practice of internal marketing is warranted.
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Marta Melguizo-Garde and Ana Yetano
International education is one of the largest and fastest growing economic sectors in the world. Degree-seeking students have become a large and growing export opportunity. Asian…
Abstract
International education is one of the largest and fastest growing economic sectors in the world. Degree-seeking students have become a large and growing export opportunity. Asian countries, especially China, are amongst the top countries sending students out, as a result, most countries aim to attract their students. Nevertheless, moving from Asian countries to the western ones is not an easy move. Chinese students face different types of challenges that need to be analysed to smooth their adaptation. This chapter analyses their performance, satisfaction and the challenges – pedagogical, language, cultural – they face to deploy the appropriate strategies to reduce failure and drop-out. Results show that the first 2 years are key for they adaptation. Language is the main barrier, it seems that the time devoted prior to their universities studies and their integration with national students is still a pending task.
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Ximing Yin, Fei Li, Jin Chen and Yuedi Zhai
University–industry (UI) collaboration is essential for knowledge and technology exchange between higher education institutions and industries, enabling enterprises to accelerate…
Abstract
Purpose
University–industry (UI) collaboration is essential for knowledge and technology exchange between higher education institutions and industries, enabling enterprises to accelerate innovation. However, few studies have investigated the collaborative innovation mechanism through which UI collaboration can enhance the accumulation of firms' intellectual capital (IC) and how this, in turn, affects their innovation-driven development.
Design/methodology/approach
Drawing from the knowledge management and collaborative innovation theory, this research proposes a theoretical framework of the inter-organization relationship between enterprises and universities to investigate the influence mechanism of UI collaboration, including academic engagement and commercialization, on corporate performance as well as the mediating role of IC by employing survey that covers 177 UI collaborations.
Findings
Empirical results show that human capital and relational capital fully mediate the relationship between academic engagement UI collaboration and corporate economic performance, while human capital partially mediates the relationship between commercialization UI collaboration and corporate economic performance. Additionally, structural capital and relational capital partially mediate the relationship between academic engagement and corporate innovation performance, while structural capital fully mediates the relationship between commercialization and corporate innovation performance.
Originality/value
This study empirically investigates how academic engagement and commercialization impact corporate performance (i.e. innovation dimension or economic dimension). It uncovers this relationship's underlying mechanism by documenting the IC's mediating impact.
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Alaa Mohamed, Mohamed Hamdy, Mohamed Bayoumi and Tarek Osman
This work describes the fabrication of composite nanogrease based on carbon nanotubes (CNTs) as an additive at different volume concentrations 0, 0.5, 1, 2 and 3 Wt.% and…
Abstract
Purpose
This work describes the fabrication of composite nanogrease based on carbon nanotubes (CNTs) as an additive at different volume concentrations 0, 0.5, 1, 2 and 3 Wt.% and investigates the correlation between CNTs and grease rheological behaviour. In addition, study the influence of shear thinning rate at various temperatures and investigates the thermal conductivity of nanogrease. The results demonstrated that grease behaves like a Newtonian viscoelastic material with a narrow linear domain. The thermal conductivity of nanogrease was enhanced by about 31.58 per cent, and the thermal and mechanical stabilities improved. Moreover, the apparent viscosity and dropping point increased by about 93 and 27 per cent, respectively.
Design/methodology/approach
Grease was dissolved in chloroform (10 Wt.%), at 25°C for 1 h. In parallel, functionalized CNTs with different volume concentrations (0.5, 1, 2 and 3 Wt.%) were dispersed in N,N-dimethylformamide; the dispersion was stirred for 15 min, and then sonicated (40 kHz, 150 W) for 30 min. Grease solution was then added to the CNTs. The nanofluid was magnetically stirred for 15 min and then sonicated for 2 h. This ensured uniform dispersion of nanoparticles in the base fluid.
Findings
Inexpensive and simple fabrication of nanogrease. Thermal conductivity of nanogrease was typically enhanced compared to other reported studies. Apparent viscosity and dropping point increases with the increase the volume concentration.
Originality/value
This work describes the inexpensive and simple fabrication of nanogrease for improving properties of lubricants, which improve power efficiency and extend lifetimes of mechanical equipment.
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Abstract
Purpose
The purpose of this paper is to study the positioning points of successful retail enterprises in China, and to try to conclude the general law for selecting the positioning points.
Design/methodology/approach
By analyzing the evaluation data of countrywide samples and the impact factors of customer satisfaction, the authors select some successful retail enterprises in China to be the study samples. On the base of that, the performance concerning positioning points of the samples are discussed.
Findings
The paper reaches five valuable conclusions: first, successful retail enterprises have definite positioning points; second, successful retail enterprises commonly have a main positioning point and a second best positioning point; third, successful retail enterprises could choose commodity, service, price or shopping environment as their positioning point; fourth, retail enterprises in the same retail format could have different positioning points; fifth, the non‐positioning points of successful retail enterprises are usually above the industry average level, while those of retail enterprises in successful tendency could hardly reach the industry average level.
Research limitations/implications
The limitation of samples (only large‐scale supermarkets) might still make the practical applications on other retail formats limited. Meanwhile, the criteria for identifying the successful enterprises in this paper are mainly customer satisfaction and loyalty, without considering the financial performance.
Practical implications
The conclusions in this paper have great significance for Chinese retail enterprises to establish a unique competitive advantage.
Originality/value
The conclusion concerning positioning points of this paper might be the first to answer the key issues in Chinese retail enterprises' positioning strategies.
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Kaliyan Mathiyazhagan, Sonu Rajak, Swayam Sampurna Panigrahi, Vernika Agarwal and Deepa Manani
In a quest to meet increasing pressure to incorporate environmental and sustainability factors due to the legislations and growing public awareness, companies are rethinking of…
Abstract
Purpose
In a quest to meet increasing pressure to incorporate environmental and sustainability factors due to the legislations and growing public awareness, companies are rethinking of strategizing their supply chain network to take control of the reverse flow of products as well. This growing interest has also led to tremendous growth in publications occurring in several reputed journals in the last few years. In this context, the purpose of this article is to perform a systematic literature survey of recent and state-of-the-art papers in order to draw insights and highlight the future directions.
Design/methodology/approach
This paper has selected and reviewed 204 papers published from the year 2002–2017. The papers were collected from the web of science and Google scholar database which have the DOI number. The selected papers were then categorized into main five core areas of RSC management namely reverse supply chain (RSC), Reverse Logistics (RL), Remanufacturing, Closed-Loop Supply Chain (CLSC) and Product Recovery Systems (PRS) and then analyzed with great detail. Finally, the research gaps that were identified from the study have been highlighted for future research opportunities.
Findings
This paper would serve as a roadmap to the managers who wish to align their forward and reverse supply chains for overall growth and development. It provides an in-depth knowledge on RSC to the researchers working in this domain. The scholars would be able to identify the areas of RSC which have been already addressed and the areas which remain unaddressed.
Originality/value
This paper presents a systematic literature survey of state-of-the-art papers that was published in the reputed journal in the area of RSC. Total 204 numbers of papers which were published in the reputed journals between 2002 and 2017 are reviewed, categorized and analysed to draw the opportunities and future research direction in the area of RSC.