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1 – 4 of 4Zhifeng Huang, Xiaoyang Ma, Zemin Qiao, Shujuan Wang and Xinli Jing
This paper aims to disclose the evolution of pendulum hardness of two-component acrylic polyurethane coatings during the cure process and attempts to describe the quantitative…
Abstract
Purpose
This paper aims to disclose the evolution of pendulum hardness of two-component acrylic polyurethane coatings during the cure process and attempts to describe the quantitative relationship between pendulum hardness and curing time. These findings are helpful for the study of fast curing acrylic polyurethane coatings.
Design/methodology/approach
The pendulum hardness method was used to monitor the hardness of two-component acrylic polyurethane coatings during curing. The quantitative relationship between pendulum hardness and curing time can be obtained with Avrami equation.
Findings
The evolution of coating pendulum hardness can be divided into three stages. By using the Avrami equation that explained the influence of both the acid value and the curing temperature on the drying speed of hydroxyl acrylic resin, the evolution of coating pendulum hardness during curing can also be accurately described.
Research limitations/implications
It should be noted that the physical meaning of the Avrami exponent, n, is not yet clear.
Practical implications
The results are of great significance for the development of fast-curing hydroxyl-functional acrylic resins, with the potential to improve the drying speed of the coatings used in automotive refinish.
Originality/value
It is novel to divide the pendulum hardness into three stages, and, for the first time, the Avrami equation is utilized to describe the evolution of coating pendulum hardness during curing.
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Hui-Wen Deng and Kwok Wah Cheung
The National People’s Congress (NPC) of People’s Republic of China, the highest organ of state power, is popularly seen as a rubber-stamp entity. However, it has been…
Abstract
Purpose
The National People’s Congress (NPC) of People’s Republic of China, the highest organ of state power, is popularly seen as a rubber-stamp entity. However, it has been substantially evolving its roles to accommodate the governance discourses within China’s political system over the decades. This study aims to explore the changes of governance discourse of the NPC within China’s political system through which to offer a thorough understanding of the NPC’s evolving substantial role in current China.
Design/methodology/approach
This study deploys a historical approach to explore the changes of governance discourse of the NPC that has seen a growing importance in China’s political agenda, as argued by this study.
Findings
The authors find that the NPC has been substantially evolving its role within China’s political system in which the Chinese Communist Party has created different governance discourses. Besides, the NPC and its Standing Committee have asserted its authority as a substantial actor within China’s political system. The NPC is no longer functioned as a rubber-stamp institution, though it is still popularized as a rubber stamp by many scholars.
Research limitations/implications
This study is a historical elaboration on the development of NPC under three governance discourses. It might be, to some extent, relatively descriptive in nature.
Originality/value
This study, therefore, sheds some light on a revisit on the governance discourses in current China.
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The purpose of this paper is to focus on the regional development of Northeast China and recommend certain alternatives to revive its economies.
Abstract
Purpose
The purpose of this paper is to focus on the regional development of Northeast China and recommend certain alternatives to revive its economies.
Design/methodology/approach
The paper reviews and analyses the transitional situations of the major three constituent provinces of Northeast China, namely Liaoning, Jilin and Heilongjiang during the economic reform.
Findings
The paper finds that, in the initial couple of decades since the foundation of The People's Republic of China, a significant part of the northeast economy mirrored the economic model of the USSR, which ineffectively reacted to market economy. The transitional economy reformed the weaknesses of the economic systems of Northeast China but led to regional economic issues in unemployment, productivity, non‐recurrent resources, and duplicated investments.
Practical implications
With the state's northeast revitalization policy and the reform measures of provincial governments, the economic situation of the region has progressively improved over the years, reflected in a higher increase rate in added value of industrial output, international trade and investments. However, the northeast still has shortfalls compared with other economic poles in China.
Originality/value
The paper concludes that the Northeast should strengthen its regional comparative advantages and adopt industrial cluster development for its revival; and it is presumed that regional international trade and foreign direct investments will be further advanced through the more open policies implemented in recent years.
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Lenka Šimková and Petra Šulcová
The purpose of this study was to investigate the influence of doping ions Mg2+, Zn2+, Al3+ to the structure of hydroxyapatite (HAP; Ca10(PO4)6(OH)2) and subsequently to evaluate…
Abstract
Purpose
The purpose of this study was to investigate the influence of doping ions Mg2+, Zn2+, Al3+ to the structure of hydroxyapatite (HAP; Ca10(PO4)6(OH)2) and subsequently to evaluate their adaptation in structure and their anticorrosive properties.
Design/methodology/approach
The substituted hydroxyapatite was synthesized by precipitation method that included the addition of Mg2+, Zn2+ and Al3+ containing precursors to partially replace Ca2+ ions in the hydroxyapatite structure. For precipitation synthesis, three ratios of Ca/P = 1; 1.67; 3 and two values of pH = 7 and 12 were selected. Samples 1 (Ca/P = 1; pH = 7), 2 (Ca/P = 1.67; pH = 7), 3 (Ca/P = 3; pH = 7) and 5 (Ca/P = 1.67; pH = 12) were chosen to monitor the influence of doping ions Mg2+, Zn2+ and Al3+ to the structure of hydroxyapatite and its anticorrosive properties.
Findings
The chosen synthesis conditions are appropriate for the formation of crystalline HAP substituted by elements Mg, Zn and Al. Only for one sample (1-Mg), two different phases (hydroxyapatite and whitlockite) were identified in the phase composition. On the basis of preliminary corrosion tests, pigments were divided into three groups pursuant to their anticorrosion effectivity: pigments with high corrosion-inhibition efficiency; pigments without anticorrosive properties; and pigments that promote corrosion processes.
Originality/value
In addition, no doping effect can be observed except for the sample 1-Mg, which consists of two phases (hydroxyapatite and whitlockite). Preliminary corrosion tests prove that some samples of HAP have extremely high anticorrosive effectivity as effectivity of the commercial pigments. The accelerated corrosion test showed that HAP samples have insufficient corrosion-inhibition properties for coating applications compared with the commercial pigment.
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