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1 – 10 of over 3000This paper aims to describe the laminar flow of Maxwell fluid past a non-isothermal rigid plate with a stream wise pressure gradient. Heat transfer mechanism is analyzed in the…
Abstract
Purpose
This paper aims to describe the laminar flow of Maxwell fluid past a non-isothermal rigid plate with a stream wise pressure gradient. Heat transfer mechanism is analyzed in the context of non-Fourier heat conduction featuring thermal relaxation effects.
Design/methodology/approach
Flow field is permeated to uniform transverse magnetic field. The governing transport equations are changed to globally similar ordinary differential equations, which are tackled analytically by homotopy analysis technique. Homotopy analysis method-Padè approach is used to accelerate the convergence of homotopy solutions. Also, numerical approximations are made by means of shooting method coupled with fifth-order Runge-Kutta method.
Findings
The solutions predict that fluid relaxation time has a tendency to suppress the hydrodynamic boundary layer. Also, heat penetration depth reduces for increasing values of thermal relaxation time. The general trend of wall temperature gradient appears to be similar in Fourier and Cattaneo–Christov models.
Research limitations/implications
An important implication of current research is that the thermal relaxation time considerably alters the temperature and surface heat flux.
Originality/value
Current problem even in case of Newtonian fluid has not been attempted previously.
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M. Mustafa, T. Hayat and A. Alsaedi
The purpose of this paper is to analyze the heat transfer effects on the stretched flow of Oldroyd-B fluid in a rotating frame. Cattaneo–Christov heat conduction model is…
Abstract
Purpose
The purpose of this paper is to analyze the heat transfer effects on the stretched flow of Oldroyd-B fluid in a rotating frame. Cattaneo–Christov heat conduction model is considered, which accounts for the influence of thermal relaxation time.
Design/methodology/approach
Based on scale analysis, the usual boundary layer approximations are used to simplify the governing equations. The equations so formed have been reduced to self-similar forms by similarity transformations. A powerful analytic approach, namely, homotopy analysis method (HAM), has been applied to present uniformly convergent solutions for velocity and temperature profiles.
Findings
Suitable values of the so-called auxiliary parameter in HAM are obtained by plotting h-curves. The results show that boundary layer thickness has an inverse relation with fluid relaxation time. The rotation parameter gives resistance to the momentum transport and enhances fluid temperature. Thermal boundary layer becomes thinner when larger values of thermal relaxation time are chosen.
Originality/value
To the authors’ knowledge, this is the first attempt to study the three-dimensional rotating flow and heat transfer of Oldroyd-B fluid.
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Michael Mustafa, Alan Coetzer, Hazel Melanie Ramos and Jorg Fuhrer
The purpose is to contribute to the debate on how job satisfaction might influence small and medium-sized enterprise (SME) employees' propensity to engage in innovative work…
Abstract
Purpose
The purpose is to contribute to the debate on how job satisfaction might influence small and medium-sized enterprise (SME) employees' propensity to engage in innovative work behaviours. The authors examine the relations between job satisfaction and innovative work behaviour and each of its sub-dimensions: idea generation, promotion and realisation. Additionally, the authors explore the potential moderating effects of openness to experience and conscientiousness on the relations between job satisfaction and innovative work behaviour and each of the sub-dimensions of innovative work behaviour.
Design/methodology/approach
Paper-based questionnaires were used to collect data from employees in 28 SMEs located in the Aargau region of Switzerland. All the SMEs were part of the high-tech manufacturing industry. The authors’ hypothesized model was tested using hierarchal regression analysis on a sample of 125 employees.
Findings
Job satisfaction was positively related to innovative work behaviour and to each of its sub-dimensions: idea generation, promotion and realisation. Openness to experience moderated the relationships between job satisfaction and innovative work behaviour and job satisfaction and the sub-dimensions idea generation, idea promotion and idea realisation. However, conscientiousness did not moderate the relationship between job satisfaction and innovative work behaviour, nor between job satisfaction and each of the sub-dimensions of innovative work behaviour.
Practical implications
Findings demonstrate that supportive work environments in SMEs which help develop job satisfaction among employees can have positive effects on the discretionary performances of employees.
Originality/value
Studies that examine relationships between job satisfaction and innovative work behaviours in SMEs are extremely sparse. This study makes novel contributions to this line of inquiry by examining how job satisfaction relates to each of the three sub-dimensions of innovative work behaviour and by exploring the potential moderating roles of two important personality traits in these relationships.
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Junaid Ahmad Khan, M. Mustafa, T. Hayat, Mustafa Turkyilmazoglu and A. Alsaedi
The purpose of the present study is to explore a three-dimensional rotating flow of water-based nanofluids caused by an infinite rotating disk.
Abstract
Purpose
The purpose of the present study is to explore a three-dimensional rotating flow of water-based nanofluids caused by an infinite rotating disk.
Design/methodology/approach
Mathematical formulation is performed using the well-known Buongiorno model which accounts for the combined influence of Brownian motion and thermophoresis. The recently suggested condition of passively controlled wall nanoparticle volume fraction has been adopted.
Findings
The results reveal that temperature decreases with an increase in thermophoresis parameter, whereas it is negligibly affected with a variation in the Brownian motion parameter. Axial velocity is negative because of the downward flow in the vertical direction.
Originality/value
Two- and three-dimensional streamlines are also sketched and discussed. The computations are found to be in very good agreement with the those of existing studies in the literature for pure fluid.
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M. Mustafa, Ammar Mushtaq, T. Hayat and A. Alsaedi
This study aims to deal with the laminar flow owing to rough rotating disk in the existence of vertical magnetic field and partial slip effects. The aim is to resolve heat…
Abstract
Purpose
This study aims to deal with the laminar flow owing to rough rotating disk in the existence of vertical magnetic field and partial slip effects. The aim is to resolve heat transfer problem in the existence of non-linear radiative flux and thermal slip effects. The study also analyzes the mass transfer process when the flow field contains chemically reacting species.
Design/methodology/approach
Modified von-Kármán transformations are applied to change the conservation equations into similar forms. The transformed equations are treated by a convenient shooting method and by contemporary built in routine bvp4c of MATLAB.
Findings
The numerical solutions are used to address the role of main ingredients of the problem, namely, wall roughness, radiation and chemical reaction on the flow fields.
Research limitations/implications
Temperature profiles are considerably affected by a parameter measuring wall to ambient temperature ratio. Furthermore, behavior of concentration field is highly influenced by the reaction rate of the diffusing species.
Originality/value
The concept of non-linear radiation in chemically reactive flow over a rotating disk is just introduced here.
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T. Hayat, Z. Iqbal, M. Mustafa and A. Alsaedi
This investigation has been carried out for thermal-diffusion (Dufour) and diffusion-thermo (Soret) effects on the boundary layer flow of Jeffrey fluid in the region of…
Abstract
Purpose
This investigation has been carried out for thermal-diffusion (Dufour) and diffusion-thermo (Soret) effects on the boundary layer flow of Jeffrey fluid in the region of stagnation-point towards a stretching sheet. Heat transfer occurring during the melting process due to a stretching sheet is considered. The paper aims to discuss these issues.
Design/methodology/approach
The authors convert governing partial differential equations into ordinary differential equations by using suitable transformations. Analytic solutions of velocity and temperature are found by using homotopy analysis method (HAM). Further graphs are displayed to study the salient features of embedding parameters. Expressions of skin friction coefficient, local Nusselt number and local Sherwood number have also been derived and examined.
Findings
It is found that velocity and the boundary layer thickness are increasing functions of viscoelastic parameter (Deborah number). An increase in the melting process enhances the fluid velocity. An opposite effect of melting heat process is noticed on velocity and skin friction.
Practical implications
The boundary layer flow in non-Newtonian fluids is very important in many applications including polymer and food processing, transpiration cooling, drag reduction, thermal oil recovery and ice and magma flows. Further, the thermal diffusion effect is employed for isotope separation and in mixtures between gases with very light and medium molecular weight.
Originality/value
Very scarce literature is available on thermal-diffusion (Dufour) and diffusion-thermo (Soret) effects on the boundary layer flow of Jeffrey fluid in the region of stagnation-point towards a stretching sheet with melting heat transfer. Series solution is developed using HAM. Further, the authors compare the present results with the existing in literature and found excellent agreement.
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Mohammad Tayeh, Rafe’ Mustafa and Adel Bino
This study investigated the impact of corporate ownership structure on agency costs in the insurance industry.
Abstract
Purpose
This study investigated the impact of corporate ownership structure on agency costs in the insurance industry.
Design/methodology/approach
The study sample included 23 insurance companies listed on the Amman Stock Exchange (ASE) from 2010 to 2019. Panel regression was used to account for the firm- and time-specific unobservable variables and system-GMM estimation was used to address endogeneity concerns.
Findings
The results show that managerial ownership positively (negatively) affects selling, general and administrative (SG&A) expenses (assets turnover), implying that unmonitored managers engage in activities that serve their own interests rather than those of shareholders. The largest shareholder's ownership has no impact on agency costs, implying that the ownership of the largest shareholder is irrelevant. However, as the wedge between the percentage of capital owned by the largest shareholders and managers increases, SG&A expenses (efficiency ratio) decrease (increases), indicating that the existence of large non-management shareholders reduces agency costs. After accounting for the endogeneity problem, the impact of ownership structure on agency costs measured by asset turnover remains robust.
Originality/value
To the best of the authors' knowledge, this study is the first to provide unique evidence and useful insights into the determinants of agency costs from a frontier market in the Middle East and North Africa (MENA), with a focus on the insurance sector. Additionally, this study uses a new measure of separation between ownership and control by calculating the wedge between managers' and large shareholders' ownership.
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Wen Li Chan and Michael James Mustafa
The purpose of this paper is to provide an overview of studies published in the Journal of Entrepreneurship in Emerging Economies (JEEE) between 2014 and 2019. The review also…
Abstract
Purpose
The purpose of this paper is to provide an overview of studies published in the Journal of Entrepreneurship in Emerging Economies (JEEE) between 2014 and 2019. The review also provides suggestions for future research in JEEE.
Design/methodology/approach
Integrative literature of 90 empirical and conceptual articles published in JEEE between 2014 and 2019. The selected articles were analyzed using content analysis.
Findings
Analysis of the 90 published articles shows that JEEE has covered a number of relevant topics related to entrepreneurship and innovation in emerging economies. In particular, scholars have adopted a variety of methods to describe such activities in emerging economies. The review also highlights the lack of comparative studies in JEEE and studies, which significantly take into account or focus on the emerging economy context.
Practical implications
The findings suggest that future scholars wishing to submit to JEEE should consider taking a more detailed account of the emerging context.
Originality/value
Since its first publication in 2014, this study represents the first review of articles found in JEEE. Specifically, the study provides a platform for future scholars wishing to submit to JEEE to take stock of the studies in the journal, thus giving them a better understanding of the field. The study also provides directions regarding areas of possible future research, which might be of interest to scholars wishing to submit to JEEE.
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Michelle She Min Ngo, Michael J. Mustafa, Craig Lee and Rob Hallak
How does a manager’s coaching behaviour encourage taking charge behaviour among subordinates? Although prior research has found a positive association between managerial coaching…
Abstract
Purpose
How does a manager’s coaching behaviour encourage taking charge behaviour among subordinates? Although prior research has found a positive association between managerial coaching behaviour and employee performance, to date few studies have examined its effect on proactive behaviours in the workplace such as taking charge. Drawing on social exchange theory (SET) and social cognitive theory (SCT), this study develops a theoretical model to examine the mediating effects of work engagement and role breadth self-efficacy (RBSE) in the relationship between managerial coaching and subordinates taking charge. Additionally, drawing on social role theory (SRT), we test whether our proposed relationships are contingent on subordinates’ gender.
Design/methodology/approach
We tested our proposed moderated-mediation model using empirical data collected across two waves from 196 employees within a large Malaysian services enterprise. Partial least squares structural equation modelling was used to test the proposed hypotheses.
Findings
The results revealed that managerial coaching has a significant, positive relationship with taking charge, work engagement and RBSE. However, only work engagement was found to partially mediate the relationship between managerial coaching and taking charge. Subordinates’ gender was found to positively attenuate the direct effect between managerial coaching and taking charge among females. However, the mediating effects of work engagement and RBSE in managerial coaching and taking charge were found to be not contingent on subordinates’ gender.
Practical implications
Finding from this study reveals that managerial coaching is useful in shaping employees' taking charge behaviour through work engagement. Hence, organisations should focus on strategies aiming to enhance managers' coaching capabilities.
Originality/value
This study extends the nomological networks of managerial coaching by highlighting it as a predictor of taking charge. Moreover, drawing on SET and SCT to explain the mechanism of managerial coaching and taking charge, we provide a novel perspective on how managerial coaching can influence taking charge. Specifically, we highlight the critical role of work engagement as a key mechanism that influences the relationship between managerial coaching and taking charge. Finally, we demonstrate managerial coaching as a means through which organisations can improve individual functioning.
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Ambreen Khursheed, Faisal Mustafa, Maham Fatima and Marriam Rao
This study proposes a new comprehensive model of entrepreneurial intentions (EIs) that enhances the understanding of the crucial entrepreneurial personality traits. This study…
Abstract
Purpose
This study proposes a new comprehensive model of entrepreneurial intentions (EIs) that enhances the understanding of the crucial entrepreneurial personality traits. This study also examines how entrepreneurial family history, gender and discipline moderate the relationship between the key entrepreneurial personality traits and EIs of university students.
Design/methodology/approach
The study introduces a new combination of important entrepreneurial personality traits, theoretically following the theory of planned behaviour (TPB). The data are collected using an entrepreneurial intention questionnaire and analysed with structural equation modelling (SEM) over a sample of 297 university students from Pakistan.
Findings
The findings highlight that one of the notable contributions to assessing EI is the negative impact of foreseeable challenges (FCs), resulting in negative EIs among university students of our sample. The authors also found significant moderating roles of gender, discipline and entrepreneurial family history in strengthening the relationship between entrepreneurial traits and EIs.
Originality/value
The study contributes both to the existing empirical and theoretical literature by examining a key set of entrepreneurial personality traits leading to enhance EIs. The results may also assist academicians to discover new ways for developing entrepreneurial traits among university students.
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