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To discover if stress corrosion cracking (SCC) of C−Mn steel is possible at ambient pressure and temperature in a CO−CO₂−H₂O environment.

Approach involved electrochemical testing, slow strain rate testing (SSRT) and fractography. The chemistry within a crack or crevice during SCC differs from that of the bulk environment. To simulate this condition, a specimen was designed containing a steel plate, microelectrodes and artificial crevice. Electrochemical tests were performed to discover if conditions likely to cause SCC could be achieved. Slow strain rate tests and fractography was also carried out to support the electrochemical data.

Results indicated that CO can adsorb onto the metal and that localized corrosion occurred at defects in the adsorbed CO layer due to CO₂, which led to the onset of SCC. Consequently, larger anodic and cathodic currents were measured with or without a crevice, when CO₂ was in solution. Similar behaviour was observed on the microelectrodes. Regions of brittle fracture were discovered on the specimen surface after SSRT were conducted in a vapour phase environment. After such tests, the ductility of the steel was found to be impaired.

Practically the results could help to predict the potential range in which SCC may occur.

Paper is new because previous results were at high pressures. However, results indicate that SCC is a danger at atmospheric pressure. The paper is of value to people in the oil and gas industry.

The paper aims to investigate the empirical impact of working capital management (WCM) on firm performance (FP) in the emerging markets of Africa. This paper also aims to investigate this relationship during the global financial crisis of 2008 (GFC, 2008).

The sample of this study comprises two leading emerging markets in Africa (Egypt and South Africa) based on the MSCI world market classification list for the period 2007–2020. The study employs various regression techniques such as fixed effect and system generalized method of moments. In addition to baseline regressions, the authors applied various preliminary tests and, finally robustness measures. Besides the dependent, independent variables, the study uses firm-level and country macroeconomic-level explanatory variables.

The study's results indicate that (1) WCM and FP exhibit a direct relationship and (2) the WCM components such as cash conversion cycle, average collection period and the average age of inventory, have a significant inverse relationship, whereas the average payment period has a direct relationship with FP. The robustness results are assessed based on the selection of an alternative proxy for FP measurement, controlling for industry, country, year effect and the exclusion of the GFC 2008.

This study has various implications in terms of theoretical, societal and practical application for practitioners, managers, investors and regulators. In terms of theoretical implications, this is the first study that contributes to the existing body of knowledge in corporate finance and managerial accounting in relation to the examination of this relationship in the African region. Finally, practitioners, including regulators, can benefit from the study's findings while devising investment policies for investors in the region. More specifically, the financial sector conduct authority (FSCA) in South Africa and the financial regulatory authority (FRA) in Egypt can consider these findings to devise financial policies that aim to foster the FP.

Society benefits from the study's findings too. The efficient management of the WCM components will raise firm profits and investment opportunities for the society in Egypt and South Africa. A firm with good performance levels will increase salaries and will provide compensation to their employees in terms of bonuses. These compensations are one of the sources for achieving FP, which is evident from existing literature as well in the case of corporate governance studies. These compensations have psychological impacts as well. As society has its basic needs and goods, compensation levels will be tilted less toward societal ethical issues.

This study has various distinguishing features, which prior studies mostly lack, as most of these studies are on an individual country dataset, shorter periods, mixed results, lesser explanatory variables and no country-related control variables. The authors addressed all these challenges and provided robust results based on various measurement alternatives for the African markets. The study's results confirm a direct relationship between WCM and FP for South Africa and Egypt reflecting the emerging markets in Africa.

This study aims to investigate and point out the variations of agency theory in the context of Sharīʿah governance in Islamic banking operations in the Kingdom of Saudi Arabia (KSA).

The study followed the approach of quantitative Corporate Governance Index (CGI) by computing the Gov-index (Gompers et al., 2003) and the Gov-score (Brown and Caylor, 2004; Saffieddine, 2009) to examine corporate governance (CG) issues using primary as well as secondary data. The primary data was generated from three full-fledged Islamic banks (IBs) and nine traditional banks with Islamic banking wings, all operating in the KSA. The approach was to provide an insight into the agency structure in the context of Islamic banking, which may lead to a trade-off between the conformity of Sharīʿah (Islamic law) rules and processes followed in safeguarding the rights of investors.

The majority of the Islamic banking services that are surveyed in this study acknowledge the significance of Sharīʿah governance and have implemented the fundamental methods, in conformity with this system. Certain flaws in Sharīʿah governance principles pertaining to audit, control and transparency are reported.

The research outcomes will be invaluable to IBs aiming to improve existing SG practices. It also has implications for IB managers to design strategies while complying with regulations and to protect the interests of all investors without breaching the ethics of Sharīʿah.

This paper adds original value to the body of knowledge on agency relationship by analysing the dynamics of agency theory in the unique and complex context of Sharīʿah governance of IBs or those offering Islamic products in the KSA. The results can be used as a valuable feedback for improvement of Sharīʿah governance in the banking system in the KSA and the Gulf region at large.

The purpose of this paper is to present the investigation of the pressure-driven flow of aluminum oxide-water based nanofluid with the combined effect of entropy generation and radiative electro-magnetohydrodynamics filled with porous media inside a symmetric wavy channel.

The non-linear coupled differential equations are first converted into a number of ordinary differential equations with appropriate transformations and then analytical solutions are obtained by homotopic approach. Numerical simulation has been designed by the most efficient approach known homotopic-based Mathematica package BVPh 2.0 technique. The long wavelength approximation over the channel walls is taken into account. The obtained analytical results have been validated through graphs to infer the role of most involved pertinent parameters, whereas the characteristics of heat transfer and shear stress phenomena are presented and examined numerically.

It is found that the velocity profile decreases near to the channel. This is in accordance with the physical expectation because resistive force acts opposite the direction of fluid motion, which causes a decrease in velocity. It is seen that when the electromagnetic parameter increases then the velocity close to the central walls decreases whereas quite an opposite behavior is noted near to the walls. This happens because of the combined influence of electro-magnetohydrodynamics. It is perceived that by increasing the magnetic field parameter, Darcy number, radiation parameter, electromagnetic parameter and the temperature profile increases, and this is because of thermal buoyancy effect. For radiation and electromagnetic parameters, energy loss at the lower wall has substantial impact compared to the upper wall. Residual error minimizes at 20th order iterations.

The proposed prospective model is designed to explore the simultaneous effects of aluminum oxide-water base nanofluid, electro-magnetohydrodynamics and entropy generation through porous media. To the best of author’s knowledge, this model is reported for the first time.

The paper aims to examine the boundary layers of a three-dimensional stagnation point flow of Al-Cu nanoparticle-suspended water-based nanofluid in an electrically conducting medium. The effect of magnetic field on second-order slip effect and convective heating is also taken into account.

The thermophysical properties of alloy nanoparticles such as density, specific heat capacity and thermal conductivity are computed using appropriate formula. The non-linear parabolic partial differential equations are transformed to ordinary differential equations and solved by shooting technique.

The influence of compositional variation of alloy nanoparticle, nanoparticle concentration, magnetic effect, slip parameters and Biot number are presented for various flow characteristics. Interesting results on skin friction and Nusselt number are obtained for different composition of aluminium and copper.

A novel result of the analysis reveals that impact of magnetic field near the boundary is suppressed by the slip effect.

The purpose of this paper is to present a novel model on the unsteady MHD flow of heat transfer in carbon nanotubes with variable viscosity over a shrinking surface.

The temperature-dependent viscosity makes the proposed model non-linear and coupled. Consequently, the resulting non-linear partial differential equations are first reformed into set of ordinary differential equations through appropriate transformations and boundary layer approximation and are then solved numerically by the Keller box method.

Graphical and numerical results are executed keeping temperature-dependent viscosity of nanofluid. It is noted that, for diverse critical points, it is found that at one side of these critical values, multiple solutions exist; on the other side, no solution exists. A comparison is also computed for the special case of existing study. The temperature and pressure profiles are also plotted for various effective parameters.

The work is original.

The purpose of this paper is to present the entropy analysis of ferrofluid inside a porous space with magnetic force. Homogenous model with second law analysis is also taken into account.

Innovative model has been proposed and designed using control volume finite element method.

Experimental results demonstrate that Bejan number augments with augment of Rayleigh. As Hartmann number rises, exergy loss enhances. Exergy loss increases by increasing Hartmann number, whereas magnetic entropy generation reduces with the decrease of Ha. The proposed model can be used for combustion process and optimizing the performance of energy conversion system like gas turbine.

To the best of authors’ knowledge, this model is reported for the first time.

The purpose of this study is to examine the simultaneous effects of Hafnium particles and partially submerged metallic particles for the flow of bi-phase coupled stress fluid over an inclined flat plane.

An unflinching free stream flow that stretches far from the surface of the plane with the possibility of containing some partially submerged metallic particles is considered. Innovative model has been proposed and designed using Runge–Kutta–Fehlberg method.

The findings show that the drag force resists the couple stress fluid, whereas the Newtonian flow is supported by increasing the velocity. For both types of flows, movement of the particle is retarded gradually against the drag force coefficient.

To the best of the authors’ knowledge, this model is reported for the first time.

The purpose of this study is to investigate the monodisperse cavitation of bubbly mixture flow for water and hydrogen mixture flows through a nozzle having a stenosis on the wall.

Two flow regions, namely, quasi-statically stable and quasi-statically unstable increase in the bubble radius, are considered. Different oscillating periods of bubbles in downstream corresponding to various values of Reynolds number are taken into account. The Range–Kutta method is used to tackle nonlinear coupled system of governing equations.

It is observed that for the larger values of Reynolds number, the void fraction at the upstream section, even at small values, yields instabilities at the downstream. Consequently, owing to sudden increase in the velocity, the bubbles strike the wall with high speed that eventually remove the existing stenosis. This process can be considered as an effective cardiac surgery for arteries with semi-blockage.

Original research work and to the best of author’s knowledge, this model is reported for the first time.