Qingchao Cheng, Guangsheng Cao, Congyu Sang, Yujie Bai, Dan Li and Ruixuan Bu
This paper aims to clarify the corrosion inhibition effect of different corrosion inhibitor systems on the corrosion of metal pipe string by potassium persulfate plugging agent…
Abstract
Purpose
This paper aims to clarify the corrosion inhibition effect of different corrosion inhibitor systems on the corrosion of metal pipe string by potassium persulfate plugging agent, so as to improve the injection capacity of polymer plugging well and reduce the corrosion of steel by oxidant plugging agent.
Design/methodology/approach
The effect of different corrosion inhibitors on the corrosion inhibition of N80 carbon steel in 1% potassium persulfate solution was studied by electrochemical experiment and weight loss experiment. The corrosion inhibition mechanism of potassium persulfate inhibitor and the synergistic mechanism among different inhibitors were analyzed.
Findings
The results indicated that when the temperature was 50°C, the inhibition effect of 0.2% sodium molybdate with a single inhibitor was the best at pH 8.5, and the inhibition rate was 70.17%. The inhibition efficiency of 0.2% sodium molybdate + 0.3% sodium silicate in the composite inhibition system can reach 94.38%. In the temperature range of 20°C–60°C, with the increase of system temperature, the inhibition effect of corrosion inhibitor will gradually weaken.
Originality/value
The corrosion inhibition system of N80 steel in potassium persulfate oxidant was mainly studied, and it clarified the influence of temperature and pH value on the corrosion inhibition effect, which provided guidance and suggestions for the corrosion inhibition of tubular string in the oilfield.
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Qingchao Sun, Xiaokai Mu, Bo Yuan, Jiawen Xu and Wei Sun
This paper aims to distinguish the relationship between the morphology characteristics of different scales and the contact performance of the mating surfaces. Also, an integrated…
Abstract
Purpose
This paper aims to distinguish the relationship between the morphology characteristics of different scales and the contact performance of the mating surfaces. Also, an integrated method of the spectrum analysis and the wavelet transform is used to separate the morphology characteristics of the actual machined parts.
Design/methodology/approach
First, a three-dimensional (3D) surface profilometer is used to obtain the surface morphology data of the actual machined parts. Second, the morphology characteristics of different scales are realized by the wavelet analysis and the power spectral density. Third, the reverse modeling engineering is used to construct the 3D contact models for the macroscopic characteristics. Finally, the finite element method is used to analyze the contact stiffness and the contact area of the 3D contact model.
Findings
The contact area and the nominal contact pressure Pn have a nonlinear relationship in the whole compression process for the 3D contact model. The percentage of the total contact area of the macro-scale mating surface is about 70 per cent when the contact pressure Pn is in the range of 0-100 MPa, and the elastic contact area accounts for the vast majority. Meanwhile, when the contact pressure Pn is less than 10MPa, the influence factor (the relative error of contact stiffness) is larger than 50 per cent, so the surface macro-scale morphology has a weakening effect on the normal contact stiffness of the mating surfaces.
Originality/value
This paper provides an effective method for the multi-scale separation of the surface morphology and then lays a certain theoretical foundation for improving the surface quality of parts and the morphology design.
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Naoyuki Yoshino and Muhammad Zubair Mumtaz
This study proposes a theoretical model for measuring the greenness factors of a firm. We develop the multifactor utility function and find that the proportion of investment in…
Abstract
This study proposes a theoretical model for measuring the greenness factors of a firm. We develop the multifactor utility function and find that the proportion of investment in green bonds is higher if greenness factors account for by a firm and vice versa. Moreover, we further develop the global aspects of greenness measures which identify how much level of greenness is maintained by a firm to make the environment green. In terms of reduction in emissions based on global measures, we report that the proportion of investment in green bonds is higher. This study argues that the difference between firm-related and global measures of greenness refers to distortion in portfolio allocation. Lastly, we compare the results of five Asian countries and report that Japanese firms are appropriately following the greenness measures while the firms operating in developing countries including Indonesia, Malaysia, Pakistan, and Thailand are far behind in implementing the greenness measures.
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From the sixteenth to eighteenth century, China underwent a commercial revolution similar to the one in contemporaneous Europe. The rise of market did foster the rise of a nascent…
Abstract
From the sixteenth to eighteenth century, China underwent a commercial revolution similar to the one in contemporaneous Europe. The rise of market did foster the rise of a nascent bourgeois and the concomitant rise of a liberal, populist version of Confucianism, which advocated a more decentralized and less authoritarian political system in the last few decades of the Ming dynasty (1368–1644). But after the collapse of the Ming Empire and the establishment of the Qing Empire (1644–1911) by the Manchu conquerors, the new rulers designated the late-Ming liberal ideologies as heretics, and they resurrected the most conservative form of Confucianism as the political orthodoxy. Under the principle of filial piety given by this orthodoxy, the whole empire was imagined as a fictitious family with the emperor as the grand patriarch and the civil bureaucrats and subjects as children or grandchildren. Under the highly centralized administrative and communicative apparatus of the Qing state, this ideology of the fictitious patrimonial state penetrated into the lowest level of the society. The subsequent paternalist, authoritarian, and moralizing politics of the Qing state contributed to China’s nontransition to capitalism despite its advanced market economy, and helped explain the peculiar form and trajectory of China’s popular contention in the eighteenth century. I also argue that this tradition of fictitious patrimonial politics continued to shape the state-making processes in twentieth-century China and beyond.
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Micro-texture is processed on the surface to reduce the friction of the contact surface, and its application is more and more extensive. The purpose of this paper is to create a…
Abstract
Purpose
Micro-texture is processed on the surface to reduce the friction of the contact surface, and its application is more and more extensive. The purpose of this paper is to create a texture function model to study the influence of surface parameters on the accuracy of the simulated surface so that it can more accurately reflect the characteristics of the real micro-textured surface.
Design/methodology/approach
The microstructure function model of rough surfaces is established based on fractal geometry and polar coordinate theory. The offset angle θ is introduced into the fractal geometry function to make the surface asperity normal perpendicular to the tangent of the surface. The 2D and 3D contour surfaces of the surface groove texture are analyzed by MATLAB simulation. The effects of fractal parameters (D and G) and texture parameter h on the curvature of the surface micro-texture model were studied.
Findings
This paper more accurately characterizes the textured 3D curved surface, especially the surface curvature. The scale coefficient G significantly affects curvature, and the influence of fractal dimension D and texture parameters on curvature can be ignored.
Originality/value
The micro-texture model of the rough surface was successfully established, and the range of fractal parameters was determined. It provides a new method for the study of surface micro-texture tribology.
Peer review
The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-09-2023-0298/