Yajun Dai, Chang Liu, Min Zhan, Xiangyu Wang, Chao He and Qingyuan Wang
The investigations provide a basis for the optimization of the alloy 6061-T6 friction stir welding (FSW) process to improve the mechanical properties of welded joints.
Abstract
Purpose
The investigations provide a basis for the optimization of the alloy 6061-T6 friction stir welding (FSW) process to improve the mechanical properties of welded joints.
Design/methodology/approach
The local deformation of the FSW joint in tension and fatigue test were experimentally investigated by digital image correlation (DIC) technique.
Findings
The local stress-strain behaviors of the sub-regions show that the plastic strain always concentrated at the heat affected zone (HAZ) on the advancing side both in tension and high cycle fatigue and eventually leads to the final fracture. The evolution of the plastic strain at very low stress is extremely slow and accounts for most of the total fatigue life. However, the local deformation exhibits a sudden increase just before the fatigue failure.
Originality/value
Based on the experimental data, the result indicates that the HAZ is the weakest zone across the weld and the strain localization in high cycle fatigue is very harmful and unpredictable for the FSW joints.
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Min Zhan, Yajun Dai, Chang Liu, Xiangyu Wang, Lang Li, Yongjie Liu, Chao He and Qingyuan Wang
The purpose of this paper is to determine (1) the relationship between microstructure and fatigue cracking behavior and (2) effect of rolling on the process of crack initiation…
Abstract
Purpose
The purpose of this paper is to determine (1) the relationship between microstructure and fatigue cracking behavior and (2) effect of rolling on the process of crack initiation and propagation in FeCrAl alloys.
Design/methodology/approach
The qualitative and quantitative fracture studies were performed using scanning electron microscopy and the non-contact optical measurement system (IFMG5).
Findings
The results show that the formation of facets, rough facets and parallel stripes in the crack initiation and early crack propagation zones are closely related to the sensitivity of crack behavior to the microstructure of the material. Besides, the rolling process has a significant influence on the small crack initiation and propagation behavior. Quantitative analysis demonstrates that the size of the stress intensity factor and plastic zone size in the rough zone is associated with the rolling process.
Originality/value
The findings of this study have the potential to enhance the understanding of the microstructural crack formation mechanisms in FeCrAl alloys and shed light on the impact of rolling on the long-term and ultra-long fatigue behavior of these alloys. This new knowledge is vital for improving manufacturing processes and ensuring the safety and reliability of FeCrAl alloys used in nuclear industry applications.
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Shanta Pandey, Min Zhan and Youngmi Kim
In spite of the War on Poverty programs of the 1960s and the economic boom of the 1990s, poverty remains consistently high among families with children in the USA. The main source…
Abstract
Purpose
In spite of the War on Poverty programs of the 1960s and the economic boom of the 1990s, poverty remains consistently high among families with children in the USA. The main source of income for these families is employment, which is largely a function of educational attainment. The purpose of this paper is to turn to aggregate and individual level data and demonstrate the power of college education in economic well‐being of women with children.
Design/methodology/approach
A nationally representative sample of single and married mothers was retrieved and the role of education in economic well‐being of these women was examined using descriptive, bi‐variate, and multiple ordinal logistic regression.
Findings
Both married and single mothers benefit immensely from a bachelors degree.
Practical implications
In recent years, policy makers in the USA have trimmed resources that promote education among poor women with children. This analysis, underscores the importance of postsecondary education in the economic well‐being of mothers with children and therefore the need for social policy promoting college education.
Originality/value
This article shows the power of education on economic well‐being of both married and single women with children.
Geoffrey Wall and Ning Ryan Zhao
The purpose of this paper is to describe and evaluate red tourism in China and, in doing so, shed light on the complex relationships between tourism, heritage and identity…
Abstract
Purpose
The purpose of this paper is to describe and evaluate red tourism in China and, in doing so, shed light on the complex relationships between tourism, heritage and identity politics.
Design/methodology/approach
Mixed methods – literature review, document analysis, interviews with government officials, travel agents and tourists.
Findings
Red tourism is an initiative to preserve, promote and pass down China’s communist past that is underpinned by political purposes. It has resulted in an imbalance between the government’s designation of communist heritage sites all over the country and the concentration of visitors in a small number of popular destinations. Red tourism fosters allegiance to the Communist Party of China. At the same time, it is expected to bring economic opportunities to remote locations through tourism spending and the branding opportunities that it provides. However, a different emphasis can be discerned at the national and local levels, whereby the former emphasizes political cohesion and the latter stresses local economic development.
Research limitations/implications
Four sites are investigated in detail out of the hundreds that might have been explored.
Practical implications
Recommendations are made to: diversify the product, increase stakeholder involvement, enhance heritage conservation plans, improve interpretation.
Social implications
Many implications for relationships between governments at all levels and the Chinese population. Also implications for the economic well-being of places and people adjacent to red tourism sites.
Originality/value
One of very few papers in either English or Chinese that addresses the red tourism policy in detail and with substantial empirical materials.
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Wei Xie and Maximilian von Zedtwitz
Through examining the development of the video compact disc player industry in China, this article aims to explore the main characteristics of world‐first innovation and identify…
Abstract
Purpose
Through examining the development of the video compact disc player industry in China, this article aims to explore the main characteristics of world‐first innovation and identify four success factors for innovation followers to launch world‐first products in catching‐up countries.
Design/methodology/approach
This article takes the form of a case study
Findings
The main characteristics of world‐first innovation in catching‐up countries include: from the demand side, innovation is mainly pulled by the local market, rather than technology‐push; from the supply side, innovation cannot isolate itself from the rest of the world – suppliers of key technologies in advanced countries play an important role; inter‐firm alliances are an increasingly important way to generate world‐first innovation; and downstream integration capabilities are required for followers to mix pieces of technologies together at competitive pricing. The success of followers from catching‐up countries to launch world‐first products hinges on the four critical factors: strengths of complementary assets; figuring out ways to meet local market demand without relying on large R&D spending; emphasizing untapped innovation opportunities by multinationals; and positioning themselves on the proper points of the globally coordinated network for innovation.
Originality/value
This article identifies the main characteristics of world‐first innovation and points out four success factors for innovation followers to launch world‐first products, which could be significant to managers in catching‐up countries. Findings of this paper are more relevant to large catching‐up countries such as India, Brazil, Mexico and Indonesia where a large domestic market could serve as important launch markets for the world‐first innovation.
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Sungwook Min, Namwoon Kim and Ge Zhan
The purpose of this study is to offer explanations of the wide variation in the impact of market size on new market entry decisions – i.e. its positive impact lessens because of…
Abstract
Purpose
The purpose of this study is to offer explanations of the wide variation in the impact of market size on new market entry decisions – i.e. its positive impact lessens because of unreliable predictability of market size on post-entry profit and entry motivations other than post-entry profit.
Design/methodology/approach
On the basis of the two explanations, this paper builds a contingency frame that the impact of market size on new market entry depends on entry-context-specific variables. It validates the contingency frame, empirically analyzing 219 parameter estimates of the impact of market size on market entry obtained from 41 existing empirical studies.
Findings
The meta-analysis results reveal that the entry-context-specific variables used in this study – niche market entry, high-tech market entry, entry by industry incumbent firms and the year of market entry – notably moderate the impact of market size on new market entry decisions, as the research frame suggests.
Research limitations/implications
This study examines the various literature and study outcomes in the areas of marketing, economics and strategy to elucidate whether and when market size is a critical driver of new market entry. In most cases, the greater the new market size, the greater is the propensity to enter the market. However, the contingency arguments stated in this paper suggest that firms may and do enter a new market even if the market size is not large at the time of entry.
Originality/value
This paper enhances the understanding of the relative importance of market size in market entry decisions, which depend on various entry contexts. It clarifies the direction and magnitude of the impact of such entry contexts.
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A mathematical model and numerical method for water flow and solute transport in a tidal river network is presented. The tidal river network is defined as a system of open…
Abstract
A mathematical model and numerical method for water flow and solute transport in a tidal river network is presented. The tidal river network is defined as a system of open channels or rivers with junctions and cross sections. As an example, the Pearl River in China is represented by a network of 104 channels, 62 nodes, and a total of 330 cross sections with 11 boundary sections for one of the applications. The simulations are performed with a supercomputer for seven scenarios of water flow and/or solute transport in the Pearl River, China, with different hydrological and weather conditions. Comparisons with available data are shown. The intention of this study is to summarize previous works and to provide a useful tool for water environmental management in a tidal river network, particularly for the Pearl River, China.
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Xiaobo Wang, Zhipeng Li, Wen Zhan, Jesong Tu, Xiaohua Zuo, Xiangyi Deng and Boyi Gui
This study aims to expand the reliability and special functions of lightweight materials for high-end equipment and green manufacturing, so that it is the first such research to…
Abstract
Purpose
This study aims to expand the reliability and special functions of lightweight materials for high-end equipment and green manufacturing, so that it is the first such research to carry out nano-composite technology of nickel-coated carbon nanotubes (Ni-CNTs)-based titanium-zirconium chemical conversion on aluminum alloy substrate.
Design/methodology/approach
Corrosion behavior of various coatings was investigated using dropping corrosion test, linear polarization and electrochemical impedance spectroscopy. The results showed that the corrosion resistance of the nano-composite conversion coatings was significantly improved to compare with the conventional titanium-zirconium conversion coating. The morphology and microdomain characteristics of the nano-composite conversion coatings were characterized by SEM/eds/EPMA, which indicated that the CNT or Ni-CNTs addition promoting the integrity coverage of coatings in a short time.
Findings
Surface morphology of titanium-zirconium (Ti-Zr)/Ni-CNT specimens exhibited smooth, compact and little pores. The nano-composite conversion coatings are mainly composed of Al, O, C and Ti elements and contain a small amount of F and Zr elements, which illuminated that CNT or Ni-CNT addition could co-deposit with aluminum and titanium metal oxides.
Originality/value
The study of corrosion resistance of nano-composite conversion coatings and the micro-zone film-formation characteristics would be provided theoretical support for the development of basic research on surface treatment of aluminum alloys.
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Principal instructional leadership and teacher participation in decision-making are conceptualized as shared instructional leadership (SIL) – a management philosophy that…
Abstract
Purpose
Principal instructional leadership and teacher participation in decision-making are conceptualized as shared instructional leadership (SIL) – a management philosophy that positively impacts student academic performance. However, the statistically meaningful relationship between SIL and student performance remains controversial as SIL functioning is influenced by various fundamental school conditions shaped by education policy, including high-stakes accountability, school autonomy and teacher professionalization. The authors examined the relationship between three SIL policy configurations and promising student performance: inclusion, exclusion and insensitive to SIL.
Design/methodology/approach
The authors used fuzzy-set qualitative comparative analysis on data obtained from the Program for International Student Assessment (2015) results, including principals' responses to leadership questions and school conditions shaped by policy, and student science scores in 64 countries and areas.
Findings
The role of SIL in student performance varied among the three configurations, and the condition of teacher professionalization in the configuration was consistently associated with high student performance.
Originality/value
SIL can create conditions for continued professional development of the teaching workforce in conjunction with school conditions shaped by policy.