Search results
1 – 10 of 24Mohsen Anwar Abdelghaffar Saleh, Dejun Wu, Shadi Emad Areef Alhaleh, Nana Adwoa Anokye Effah and Azza Tawab Abdelrahman Sayed
This paper aims to examine the impact of board gender diversity (BOGD) following the adoption of gender quota legislation on earnings management (EM) in an emerging market, Egypt…
Abstract
Purpose
This paper aims to examine the impact of board gender diversity (BOGD) following the adoption of gender quota legislation on earnings management (EM) in an emerging market, Egypt, whose cultural and economic conditions and institutional context are unlike most previously studied countries’ context.
Design/methodology/approach
The authors use ordinary least squares (OLS) regression to estimate the impact of gender quota legislation on EM using data from listed companies in Egypt from 2015 to 2022. Difference-in-difference (DID) approach estimation was used to validate the robustness of the main results.
Findings
This paper documents that gender diversity on boards has a significantly negative impact on EM. In addition, this paper provides robust evidence using the DID approach to show that BOGD is significantly negatively linked with EM for the period following gender quota legislation. Furthermore, the results support the critical mass and agency theories.
Practical implications
The findings of this study have important implications for Egyptian companies, regulatory bodies and investors in emerging markets. Specifically, these results suggest that when choosing board members, enterprises should pay particular attention to BOGD, and female involvement in all listed firms should be monitored by regulators.
Social implications
This paper provides evidence supporting the positive contribution of women in society by enhancing the economic performance of Egyptian firms and promoting the country’s sustainable development strategy in light of Egypt vision 2030.
Originality/value
As per the authors' knowledge, this empirical study is unique in investigating the impact of BOGD quota regulation on EM in Egypt. This paper contributes to BOGD as a major factor in improving financial reporting quality in Egyptian companies.
Details
Keywords
Mohsen Anwar Abdelghaffar Saleh, Dejun Wu and Azza Tawab Abdelrahman Sayed
This chapter aims to examine the impact of whistleblowing policy (WH) on earnings management (EM) in an emerging market, Egypt. Our sample period from 2014 to 2019: the…
Abstract
This chapter aims to examine the impact of whistleblowing policy (WH) on earnings management (EM) in an emerging market, Egypt. Our sample period from 2014 to 2019: the pre-whistleblowing policy period is 2014–2016 and the post-whistleblowing policy period is 2017–2019 with a total of 780 observations and the data are analyzed using ordinary least squares (OLS) regression analysis. Data are collected from annual reports, corporate governance reports, and companies’ website. The empirical analysis shows that whistleblowing policy coefficient is negative and significantly impacts EM in Egyptian firms. The result shows that when the firm adopts a whistleblowing policy, it led to decrease in EM. In addition, we provide strong and robust evidence by the difference-in-difference (DID) method to show that whistleblowing is significantly negatively associated with the extent of EM, which indicates that firms have an effective whistleblowing policy and can have several benefits. Firstly, it can help to identify and prevent illegal or unethical behavior within an organization, which can ultimately save the company from potential legal and reputational damage. Secondly, a whistleblowing policy can empower employees to speak up about any concerns they have, without fear of retaliation, which can help to create a more transparent and ethical work environment. Overall, an effective whistleblowing policy can contribute to the long-term success of a company and the broader economy. The findings of this chapter are relevant to policymakers, governments, management, employees, and shareholders to constraining EM in Egyptian firms.
Details
Keywords
Li Jiahong and Kong Dejun
The purpose of this paper is to improve the salt spray corrosion and electrochemical corrosion performances of H13 hot work mould steel, Cr–Ni coatings with the different Cr and…
Abstract
Purpose
The purpose of this paper is to improve the salt spray corrosion and electrochemical corrosion performances of H13 hot work mould steel, Cr–Ni coatings with the different Cr and Ni mass ratios are fabricated using a laser cladding (LC), which provides an experimental basis for the surface modification treatment of H13 steel.
Design/methodology/approach
Cr–Ni coatings with the different Cr and Ni mass ratios were firstly fabricated on H13 hot work mould steel using a laser cladding (LC). The salt spray corrosion (SSC) and electrochemical corrosion performances of Cr–Ni coatings in 3.5 Wt.% NaCl solution were investigated to analyze the corrosion mechanism, and the effect of mass ratios of Cr and Ni on their corrosion mechanism was discussed.
Findings
The laser cladded Cr–Ni coatings with the different Cr and Ni mass ratios are composed of Cr–Ni compounds, which are metallurgically combined with the substrate. The SSC resistance of Cr–Ni coating with the Cr and Ni mass ratios of 24:76 is the highest. The electrochemical corrosion resistance of Cr–Ni coating with the Cr and Ni mass ratio of 24:76 is the best among the three kinds of coatings.
Originality/value
In this study, the corrosion resistance of laser cladded Cr–Ni coatings with the Cr and Ni mass ratios of 17: 83, 20: 80 and 24: 76 was first evaluated using salt spray corrosion (SSC) and electrochemical tests, and the effect of mass ratios of Cr and Ni on their corrosion mechanism was discussed.
Details
Keywords
Hu Yan and Kong Dejun
This paper aims to investigate the effects of Cr and Ta additions on the friction performance and corrosion-wear mechanism of Fe90-Al2O3 coating in 3.5% NaCl solution.
Abstract
Purpose
This paper aims to investigate the effects of Cr and Ta additions on the friction performance and corrosion-wear mechanism of Fe90-Al2O3 coating in 3.5% NaCl solution.
Design/methodology/approach
Cr and Ta reinforced Fe90-Al2O3 coatings were prepared on Q235 steel by laser cladding. The effects of Cr and Ta addition on the coefficient of friction (COF) and wear rate of Fe90-Al2O3 coating were investigated using a friction tester, and the wear model was established to discuss its corrosion-wear mechanism.
Findings
The average COFs of Fe90-Al2O3, Fe90-Al2O3-10%Cr and Fe90-Al2O3-10%Ta coatings in 3.5% NaCl solution are 0.57, 0.42 and 0.75, respectively, and the corresponding wear rates are 9.42 × 10−7, 5.31 × 10−7 and 7.02 × 10−7 mm3 s−1 N−1, respectively. The corrosion-wear resistance of Fe90-Al2O3-10%Cr coating is the best among the three kinds of coatings, in which the additions of Cr and Ta play a role in solid solution strengthening.
Originality/value
The Fe90-Al2O3 coating was strengthened by the additions of Cr and Ta to improve its corrosion-wear resistance in 3.5% NaCl solution.
Details
Keywords
Kong Dejun and Li Jiahong
The purpose of this paper is to evaluate the salt spray corrosion (SSC) and electrochemical corrosion performances of CrNi, TiAlN/NiCr and CrNi–Al2O3–TiO2 coatings on H13 steel…
Abstract
Purpose
The purpose of this paper is to evaluate the salt spray corrosion (SSC) and electrochemical corrosion performances of CrNi, TiAlN/NiCr and CrNi–Al2O3–TiO2 coatings on H13 steel, which improved the corrosion resistance of H13 hot work mold.
Design/methodology/approach
CrNi, TiAlN/NiCr and CrNi–Al2O3–TiO2 coatings were fabricated on H13 hot work mold steel using a laser cladding and cathodic arc ion plating. The SSC and electrochemical performances of obtained coatings were investigated using a corrosion test chamber and electrochemical workstation, respectively. The corrosion morphologies, microstructure and phases were analyzed using an electron scanning microscope, optical microscope and X-ray diffraction, respectively, and the mechanisms of corrosion resistance were also discussed.
Findings
The CrNi coating is penetrated by corrosion media, producing the oxide of Fe3O4 on the coating surface; and the TiAlN coating is corroded to enter into the CrNi coating, forming the oxides of TiO and NiO, the mechanism is pitting corrosion, whereas the CrNi–Al2O3–TiO2 coating is not penetrated, with no oxides, showing the highest SSC resistance among the three kinds of coatings. The corrosion potential of CrNi coating, TiAlN/CrNi and CrNi–Al2O3–TiO2 coatings was –0.444, –0.481 and –0.334 V, respectively, and the corresponding polarization resistances were 3,074, 2,425 and 86,648 cm2, respectively. The electrochemical corrosion resistance of CrNi–Al2O3–TiO2 coating is the highest, which is enhanced by the additions of Al2O3 and TiO2.
Originality/value
The CrNi, TiAlN/CrNi and CrNi–Al2O3–TiO2 coatings on H13 hot work mold were firstly evaluated by the SSC and electrochemical performances.
Details
Keywords
Zhang Jing and Kong Dejun
To improve the electrochemical corrosion resistance of cold sprayed Al coating.
Abstract
Purpose
To improve the electrochemical corrosion resistance of cold sprayed Al coating.
Design/methodology/approach
A cold sprayed aluminum (Al) coating fabricated on S355 structural steel was oxidized using a micro arc oxidation (MAO). The electrochemical corrosion and impedance spectroscopy were tested to investigate its corrosion performance.
Findings
The MAO film is primarily α-Al2O3 and γ-Al2O3, which increases its density and surface quality. The corrosion potential is positively shifted by 0.2 V, and the electrochemical impedance is significantly increased.
Originality/value
A cold sprayed Al coating on S355 steel was first oxidized using a MAO. The effects of MAO on the microstructure of Al coating were investigated to analyze its electrochemical corrosion behavior.
Details
Keywords
This paper aims to enhance the corrosive wear and electrochemical corrosion of Ti–6Al–4V alloy.
Abstract
Purpose
This paper aims to enhance the corrosive wear and electrochemical corrosion of Ti–6Al–4V alloy.
Design/methodology/approach
A CoCrAlYTaSi alloy coating was fabricated on Ti–6Al–4V alloy using a laser thermal spraying (LTS). The surface and cross-section morphologies, chemical elements, phases and bonding strength of the obtained coating were analyzed using a scanning electron microscope, energy dispersive spectroscope, X-ray diffraction and scratch test, respectively, The corrosive wear and electrochemical corrosion of CoCrAlYTaSi coating in 3.5 Wt.% NaCl solution were investigated using a wear tester and electrochemical workstation, respectively.
Findings
The average coefficient of frictions (COFs) of CoCrAlYTaSi coating under the wear loads of 2, 4 and 6 N are 1.31, 1.02 and 0.88, respectively; and the corresponding wear rates are 0.66 × 10−4, 1.10 × 10−4 and 1.30 × 10−4 mm3·N–1·m–1, respectively. The wear mechanism under the wear load of 2 N is abrasive wear, while those under the wear loads of 4 and 6 N are adhesive wear and abrasive wear. The charge transfer resistance of CoCrAlYTaSi coating is 5.368 × 105 Ω·cm2, higher than 2.193 × 105 of the substrate.
Originality/value
In this study, a CoCrAlYTaSi coating was firstly fabricated on Ti–6Al–4V alloy using a LTS. Its corrosive wear and electrochemical corrosion in 3.5 Wt.% NaCl solution were investigated, which played a protective role of corrosive wear on Ti–6Al–4V alloy.
Details
Keywords
Peng Li, Xiya Huang and Dejun Kong
The purpose of this paper is to investigate the effects of load and speed on the corrosive wear performance of Al coating in 3.5% NaCl solution, which provided an experimental…
Abstract
Purpose
The purpose of this paper is to investigate the effects of load and speed on the corrosive wear performance of Al coating in 3.5% NaCl solution, which provided an experimental reference for the anti-corrosion engineering on offshore platforms.
Design/methodology/approach
A layer of Al coating was prepared on S355 steel using an arc spraying. The corrosive wear test was carried out with CFT–1 type surface property tester. The effects of load and speed on the corrosive wear performance of Al coating were investigated and the wear mechanism was also discussed. The electrochemical tests were conducted using a CHI660E type electrochemical workstation, the anti-corrosion mechanism was analyzed.
Findings
The average coefficient of frictions (COFs) of Al coating under loads of 1.5, 2.5 and 3.5 N are 0.745, 0.847 and 0.423, the wear mechanism is abrasive wear. The average COFs of Al coating at the speeds of 200, 400 and 600 rpm are 0.745, 0.878 and 0.617, respectively, the wear mechanism at the speeds of 200 and 400 rpm are abrasive wear, while that at the speed of 600 rpm is abrasive wear and fatigue wear. The anti-corrosion mechanism is the isolation of Cl– corrosion and cathodic protection of sacrificial anode.
Originality/value
This paper mainly studied corrosive wear and electrochemical corrosion performances of Al coating. This study hereby confirms that this manuscript is the original work and has not been published nor has it been submitted simultaneously elsewhere. This paper further confirms that all authors have checked the manuscript and have agreed to the submission.
Details
Keywords
He Chuang, Wang Fan, Liu Zhicheng and Kong Dejun
The purpose of this study is to investigate the effect of laser scanning speed (LSS) on the corrosive-tribological performance of Ni-60%WC coating in Wusu mine water, which was…
Abstract
Purpose
The purpose of this study is to investigate the effect of laser scanning speed (LSS) on the corrosive-tribological performance of Ni-60%WC coating in Wusu mine water, which was beneficial to improve the friction–wear performance of cylinder liner on water injection pump.
Design/methodology/approach
Ni-60%WC coatings were fabricated on 45 steel by laser cladding, and the microstructure and tribological performance was analyzed using a super depth of field microscope and ball-on-plate friction tester, and the wear mechanism was also discussed.
Findings
At room temperature (RT, 25 ± 2 °C), the average coefficients of friction of substrate and Ni-60%WC coatings fabricated at the LSS of 6, 10, 12 and 14 mm/s are 0.48 ± 0.08, 0.23 ± 0.01, 0.21 ± 0.05, 0.22 ± 0.02 and 0.25 ± 0.04, respectively, and the corresponding wear rates are 8.755 × 104, 4.525 × 103, 1.539 × 103, 1.957 × 103 and 2.743 × 103 µm3·s–1·N–1, respectively, showing that the coating fabricated at the LSS of 10 mm/s has best friction reduction and wear resistance. The wear mechanism of Ni-60%WC coating is abrasive wear, fatigue wear and oxidative wear, which is resulted from the WC particles with the high-hardness.
Originality/value
Ni-60%WC coatings were first applied for cylinder liner, and the effect of laser scanning speed on its tribological performance was investigated.
Details