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1 – 10 of 45Muhammad Ijaz Khan, Sohail Ahmad Khan, Tasawar Hayat, Muhammad Faisal Javed and Muhammad Waqas
This paper aims to address the flow features of Ree–Eyring fluid between two rotating disks subject to the magnetic field. Heat transfer features are discussed through viscous…
Abstract
Purpose
This paper aims to address the flow features of Ree–Eyring fluid between two rotating disks subject to the magnetic field. Heat transfer features are discussed through viscous dissipation and nonlinear thermal radiation. Impact of thermophoresis and Brownian movement are elaborated. Physical characteristics of entropy generation optimization in nanofluid with homogeneous and heterogeneous chemical reaction are discussed.
Design/methodology/approach
The nonlinear system leads to ordinary one through the implementation of adequate transformation and then tackled analytically for a convergent series solution by homotopy analysis method.
Findings
The prime objective of the present research has been given to investigate entropy generation in Ree–Eyring fluid flow between two rotating disks subjected to the magnetic field. Vital features, namely, Brownian motion and thermophoresis have been addressed. Total entropy rate is computed using the second law of thermodynamics.
Originality/value
No such work yet exists in the literature.
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Muhammad Faisal Javed, Mohammed Jameel, Muhammad Ijaz Khan, Sumaira Qayyum, Niaz B. Khan and Tufail Ahmad Khan
This study aims to focus on second grade fluid flow over a rotating disk in the presence of chemical reaction. Uniform magnetic field is also taken into account. Because of the…
Abstract
Purpose
This study aims to focus on second grade fluid flow over a rotating disk in the presence of chemical reaction. Uniform magnetic field is also taken into account. Because of the smaller magnetic Reynolds number, induced magnetic field is negligible. Heat equation is constructed by considering heat source/sink.
Design/methodology/approach
Suitable variables are used to transform nonlinear partial differential equations to ordinary ones. Convergent series solutions are attained by applying homotopy analysis method.
Findings
Trends of different parameters on concentration, velocity and temperature are shown graphically. Skin friction coefficient and local Nusselt number are calculated and investigated under the effect of elaborated parameters. An elevation in the value of magnetic field parameter causes collapse in the velocity distributions. Velocity distribution in increasing function of viscoelastic parameter. Temperature and concentration profiles are decreasing functions of viscoelastic parameter. Concentration distribution reduces by increasing the chemical reaction parameter. There is more surface drag force for larger M, while opposite behavior is noted for β.
Originality/value
To the best of the authors’ knowledge, such consideration is yet to be published in the literature.
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Sohail Ahmad Khan, Muhammad Ijaz Khan, Tasawar Hayat, Muhammad Faisal Javed and Ahmed Alsaedi
The purpose of this paper is to address the impact of induced magnetic field in mixed convective stagnation flow of TiO2-Cu-water hybrid nanofluid towards a stretchable sheet…
Abstract
Purpose
The purpose of this paper is to address the impact of induced magnetic field in mixed convective stagnation flow of TiO2-Cu-water hybrid nanofluid towards a stretchable sheet. Non-linear thermal radiation and heat source/sink are accounted. Flow of hybrid nanofluid is discussed. Non-linear partial differential expressions are converted to ordinary ones through appropriate transformations.
Design/methodology/approach
The obtained systems are solved for convergence solutions via homotopy analysis method. Graphical results are discussed for different physical variables on the velocity, induced magnetic field and temperature fields for both Cu water nanofluid and TiO2-Cu-water hybrid nanofluid. Finally, the effect of different physical variables on skin friction coefficient (Cfx) and Nusselt number Nux in the presence of water nanofluid and TiO2-Cu-water hybrid nanofluid are discussed.
Findings
Velocities and induced magnetic field are increasing functions of mixed convection parameter and nanoparticle volume fraction. Temperature rises for higher radiation parameter. Skin friction is greater in case of Cu-water nanoliquid, while Nusselt number is less for Cu-water nanofluid when they are compared with hybrid nanoliquid TiO2-Cu-water.
Originality/value
No such work is not yet present in the literature.
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Muhammad Ijaz Khan, Sohail Ahmad Khan, Tasawar Hayat, Muhammad Faisal Javed and Ahmed Alsaedi
This study aims to examine the flow characteristics of Ree–Eyring fluid between two rotating disks. The characteristics of heat transfer are discussed in presence of viscous…
Abstract
Purpose
This study aims to examine the flow characteristics of Ree–Eyring fluid between two rotating disks. The characteristics of heat transfer are discussed in presence of viscous dissipation, heat source/sink and nonlinear radiative heat flux.
Design/methodology/approach
Nonlinear flow expressions lead to ordinary ones through adequate similarity transformations. The ordinary differential system has been tackled through optimal homotopic method. The impact of different flow variables on the velocity field, entropy generation rate and temperature fields is graphically discussed. The surface drag force and heat transfer rate are numerically examined via various pertinent parameters.
Findings
By minimization of values of stretching parameter and Brinkman number, the entropy generation rate can be controlled. The entropy generation rate enhances for higher values of magnetic parameter, while the Bejan number is decreased via magnetic parameter.
Originality/value
No such work is yet published in the literature.
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Muhammad Ijaz Khan, M.Z. Kiyani, Tasawar Hayat, Muhammad Faisal Javed and I. Ahmad
This paper aims to address double-stratified stagnation-point flow of Williamson nanomaterial with entropy generation. Flow through porous medium is discussed. Energy equation is…
Abstract
Purpose
This paper aims to address double-stratified stagnation-point flow of Williamson nanomaterial with entropy generation. Flow through porous medium is discussed. Energy equation is modeled in existence of viscous dissipation, Brownian motion and thermophoresis. Furthermore, convective boundary conditions are considered. Total entropy rate is presented.
Design/methodology/approach
The non-linear flow expressions are converted to ordinary ones by implementation of suitable transformations. The obtained ordinary system is tackled for series solutions via homotopy analysis method.
Findings
Till date no one has considered the irreversibility analysis in stagnation-point flow of Williamson nanomaterial with double stratification, porous medium and convective conditions. The basic objective of present research is to investigate the convective stagnation point flow of Williamson liquid with entropy concept and porous medium.
Originality/value
As per the authors’ knowledge, no such work is yet present in the literature.
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Muhammad Qamar Zia, Ummi Naiemah Saraih, Muhammad Sufyan Ramish, Asima Faisal and Muhammad Naveed
The objective of this research is to investigate how ethical leadership (EL) directly or indirectly impacts adaptive performance (AP) within the hospitality industry, focusing on…
Abstract
Purpose
The objective of this research is to investigate how ethical leadership (EL) directly or indirectly impacts adaptive performance (AP) within the hospitality industry, focusing on the mediation of trust in leaders (TiL) and job crafting (JC).
Design/methodology/approach
Data were gathered from 328 employees and 66 leaders across 28 hotels in central and northern areas of Pakistan using a time-lagged methodology. Structural equation modeling was applied for data analysis using SPSS and AMOS.
Findings
Findings present a strong connection between EL and AP, with both TiL and JC serving as independent and sequential mediators. The study also revealed that EL is directly linked to TiL and JC.
Practical implications
Findings suggest that hospitality firms should foster a culture of EL by focusing on hiring and employees’ development programs, enhancing their dynamic capabilities to adapt to the changes.
Originality/value
By examining the AP of frontline employees, this study identifies new outcomes of EL within the hospitality context. Furthermore, it also contributes to the literature by exploring the novel impact of EL on AP through TiL and JC.
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Muhammad Faisal, Iftikhar Ahmad, Qazi Zan-Ul-Abadin, Irfan Anjum Badruddin and Mohamed Hussien
This study aims to explore entropy evaluation in the bi-directional flow of Casson hybrid nanofluids within a stagnated domain, a topic of significant importance for optimizing…
Abstract
Purpose
This study aims to explore entropy evaluation in the bi-directional flow of Casson hybrid nanofluids within a stagnated domain, a topic of significant importance for optimizing thermal systems. The aim is to investigate the behavior of unsteady, magnetized and laminar flow using a parametric model based on the thermo-physical properties of alumina and copper nanoparticles.
Design/methodology/approach
The research uses boundary layer approximations and the Keller-box method to solve the derived ordinary differential equations, ensuring numerical accuracy through convergence and stability analysis. A comparison benchmark has been used to authenticate the accuracy of the numerical outcomes.
Findings
Results indicate that increasing the Casson fluid parameter (ranging from 0.1 to 1.0) reduces velocity, the Bejan number decreases with higher bidirectional flow parameter (ranging from 0.1 to 0.9) and the Nusselt number increases with higher nanoparticle concentrations (ranging from 1% to 4%).
Research limitations/implications
This study has limitations, including the assumption of laminar flow and the neglect of possible turbulent effects, which could be significant in practical applications.
Practical implications
The findings offer insights for optimizing thermal management systems, particularly in industries where precise control of heat transfer is crucial. The Keller-box simulation method proves to be effective in accurately predicting the behavior of such complex systems, and the entropy evaluation aids in assessing thermodynamic irreversibilities, which can enhance the efficiency of engineering designs.
Originality/value
These findings provide valuable insights into the thermal management of hybrid nanofluid systems, marking a novel contribution to the field.
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Muhammad Faisal, Iftikhar Ahmad and Abdur Rashid
The present study aims to encompass the bidirectional magnetized flowing of a hybrid-nanofluid over an unsteady stretching device with the inclusion of thermal radiation and…
Abstract
Purpose
The present study aims to encompass the bidirectional magnetized flowing of a hybrid-nanofluid over an unsteady stretching device with the inclusion of thermal radiation and entropy generation. Brick-shaped nanoparticles (zinc-oxide and ceria) are suspended in water, serving as the base-fluid to observe the performance of the hybrid mixture. The Maxwell thermal conductivity relation is employed to link the thermophysical attributes of the hybrid mixture with the host liquid. Additionally, a heat source/sink term is incorporated in the energy balance to enhance the impact of the investigation. Both prescribed-surface-temperature (PST) and prescribed-heat-flux (PHF) conditions are applied to inspect the thermal performance of the hybrid nanofluid.
Design/methodology/approach
The transport equations in Cartesian configuration are transformed into ordinary differential equations (ODEs), and an efficient method, namely the Keller-Box method (KBM), is utilized to solve the transformed system. Postprocessing is conducted to visually represent the velocity profile, thermal distribution, skin-friction coefficients, Bejan number, Nusselt number and entropy generation function against the variations of the involved parameters.
Findings
It is observed that more entropy is generated due to the increases in temperature difference and radiation parameters. The Bejan number initially declines but then improves with higher estimations of unsteadiness and Hartmann number. Overall, the thermal performance of the system is developed for the PST scenario than the PHF scenario for different estimations of the involved constraints.
Originality/value
To the best of the authors' knowledge, no investigation has been reported yet that explains the bidirectional flow of a CeO2-ZnO/water hybrid nanofluid with the combined effects of prescribed thermal aspects (PST and PHF) and entropy generation.
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Muhammad Ijaz Khan, Shahid Farooq, Tasawar Hayat, Faisal Shah and Ahmed Alsaedi
The novel mechanical, chemical and thermodynamics characteristics of both single- and multi-wall carbon nanotubes (CNTs) make them a subject of much attention for the scientists…
Abstract
Purpose
The novel mechanical, chemical and thermodynamics characteristics of both single- and multi-wall carbon nanotubes (CNTs) make them a subject of much attention for the scientists and engineers from all domains. Fluid flows subject to CNTs are significant in biomedical engineering, energy storage systems, domestic and industrial cooling, automobile industries and solar energy collectors, etc. Keeping such effectiveness of CNTs in mind, this paper aims to examine peristaltic flow subject to CNTs in an asymmetric tapered channel. Both single and multiple walls CNTs are considered. The viscosity of nanomaterial depends on nanoparticles volume fraction and temperature. Total entropy rate through second law of thermodynamics is calculated. Heat source/sink and nonlinear heat flux are accounted.
Design/methodology/approach
The complicated flow expressions are simplified through lubrication approach. The velocity, temperature and entropy expressions are numerically solved by the built-in-shooting method.
Findings
The solutions for entropy generation, temperature and velocity are plotted, and the influences of pertinent variables are examined. The authors noticed that entropy generation is an increasing function of the Brinkman number.
Originality/value
The originality of this work is to communicate peristaltic CNTs-based nanomaterial peristaltic flow of viscous fluid in an asymmetric channel. No such consideration is yet published in the literature.
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Qurat-ul-Ain Burhan, Muhammad Asif Khan and Muhammad Faisal Malik
This study aims to identify the impact of ethical leadership on ethical voice by determining two paths covering relational identification and psychological safety. The first path…
Abstract
Purpose
This study aims to identify the impact of ethical leadership on ethical voice by determining two paths covering relational identification and psychological safety. The first path focused on relational identification and psychological safety. Alternatively, the second path focused on organizational identification and psychological ownership leading to ethical voice. The specific objective of the study is to develop and test an integrated model of ethical leadership.
Design/methodology/approach
The objectives were achieved through the adoption of quantitative research techniques. Two hundred forty-eight samples were collected from the banking sector using quantitative research techniques, and data was gathered through a self-administrated questionnaire. Exploratory and confirmatory factor analyses were used through AMOS to generate the results and test hypotheses.
Findings
The results suggested a significant impact of ethical leadership on ethical voice, while the other paths’ results, such as relational identification, psychological safety, organizational identification and psychological ownership, suggested partial mediation. The study result adds new insights into ethical leadership and social exchange theory since it tested overlooked paths in the literature, such as relational identification and psychological safety.
Research limitations/implications
The research highlights the significance of ethical voice as a desirable organizational behavior. Ethical voice contributes to a culture of accountability, transparency and ethical decision-making. Organizations should establish channels and platforms for employees to voice ethical concerns and suggestions. This may involve regular feedback sessions, anonymous reporting mechanisms and protection policies for whistleblowers. Leaders should actively encourage and value ethical voices as a valuable contribution to the ethical climate of the organization.
Practical implications
The study found that ethical leaders influence their followers in such a way that they adopt ethical behavior. It is also validated that organizational ethics are shared by employees who interact with ethical leaders. So, departments should train such leaders because ethical leadership positively affects followers’ attitudes and behaviors, and organizations should encourage ethical behavior in supervisors and subordinates. The study also found that relational and organizational identification helps employees develop psychological capabilities, which leads to reporting workplace misconduct. The current study tested these mechanisms collectively and found that ethical leadership significantly contributes to ethical voice.
Social implications
The current study highlighted the role of ethical leaders in promoting ethical behavior, improving employee well-being and engagement, cultivating collaboration and inclusion, and making a contribution to the overall ethical climate within organizations and society as a whole. Organizations can have a positive impact on the social fabric by cultivating a culture of ethics, respect and social responsibility if they make these considerations their top priorities.
Originality/value
The current study is unique since it is intended to develop and test an integrated model of ethical leadership and ethical voice. This research combines an integrated model, focusing on employees’ identities and self-concepts and examining ethical voice as a behavioral outcome.
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