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Metal-cooled reactors generally use molten metals such as sodium, potassium or a combination of sodium and potassium because of their excellent heat transfer properties so that the reactor can operate at much lower pressures and higher temperatures. The purpose of this paper is to investigate the stability of natural convection in an inclined ring filled with molten potassium under the influence of a radial magnetism.

A numerical simulation of electrically conductive fluid natural convection stability is performed on an inclined cylindrical annulus under the influence of a radial magnetism. The upper and lower walls are adiabatic, while the internal and external cylinders are kept at even temperatures. The equations governing this fluid system are solved numerically using finite volume method. The SIMPLER algorithm is used for pressure-speed coupling in the momentum equation.

Numerical results for various effective parameters that solve the problem in the initial oscillatory state are discussed in terms of isobars, isotherms and flow lines in the annulus for a wide range of Hartmann numbers (0 ≤ Ha ≤ 80), inclination angles (0 ≤ γ ≤ 90°) and radii ratios λ ≤ 6. The dependency stability diagrams between complicated situations with the critical value of the Rayleigh number RaCr and the corresponding frequency FrCr are established on the basis of the numeric data of this investigation. The angle of inclination and the radii ratio of the annulus have a significant effect on the stabilization of the magneto-convective flux and show that the best stabilization of the natural oscillatory convection is obtained by the intensity of the strongest magnetic field, the high radii ratio and inclination of the annulus at γ = 30°.

This numerical model is selected for its various applications in technology and industry.

To the best of the authors’ knowledge, the influence of the inclination of the cylindrical annulus (ring), with various radii ratio, on natural oscillatory convection under a radial magnetism has never been investigated.

The purpose of this paper is to evaluate the temperature, the Dirichlet conditions have been considered to the parallel horizontal plates. The model of generalized Brinkman-extended Darcy with the Boussinesq approximation is considered and the governing equations are computed by COMSOL multiphysics.

In the current study, the thermodynamic irreversible principle is applied to study the unsteady Poiseuille–Rayleigh–Bénard (PRB) mixed convection in a channel (aspect ratio A = 5), with the effect of a uniform transverse magnetic field.

The effects of various flow parameters on the fluid flow, Hartmann number (Ha), Darcy number (Da), Brinkman number (Br) and porosity (ε), are presented graphically and discussed. Numerical results for temperature and velocity profiles, entropy generation variations and contour maps of streamlines, are presented as functions of the governing parameter mentioned above. Basing on the generalized Brinkman-extended Darcy formulation, which allows the satisfaction of the no-slip boundary condition on a solid wall, it is found that the flow field and then entropy generation is notably influenced by the considering control parameters. The results demonstrate that the flow tends toward the steady-state with four various regimes, which strongly depends on the Hartman and Darcy numbers variations. Local thermodynamic irreversibilities are more confined near the active top and bottom horizontal walls of the channel when increasing the Da and decreasing the Hartmann number. Entropy generation is also found to be considerably affected by Brinkman number variation.

In the present work, we are presenting our investigations on the influence of a transverse applied external magnetohydrodynamic on entropy generation at the unsteady laminar PRB flow of an incompressible, Newtonian, viscous electrically conducting binary gas mixture fluid in porous channel of two horizontal heated plates. The numerical solutions for the liquid velocity, the temperature distribution and the rates of heat transport and entropy generation are obtained and are plotted graphically.

This article aims to develop a new theory that can better explain and predict how and when humans interact with commercial robots. To this end, utility maximization theory (UMT) along with four principles and propositions that may guide how human-to-commercial robot interactions are developed.

This article conceptualizes UMT by drawing from social exchange, conservation of resources, and technology-driven theories.

This article proposes UMT, which consists of four guiding principles and propositions. First, it is proposed that the human must invest sufficient resources to initiate a human-to-commercial robot interaction. Second, the human forms an expectation of utility gain maximization once a human-to-commercial robot interaction is initiated. Third, the human severs a human-to-commercial robot interaction if the human is unable to witness maximum utility gain upon the interaction. Finally, once the human severs a human-to-commercial robot interaction, the human seeks to reinvest sufficient resources in another human-to-commercial robot interaction with the same expectation of utility maximization.

This article is one of the few studies that offers a theoretical foundation for understanding the interactions between humans and commercial robots. Additionally, this article provides several managerial implications for managing effective human-to-commercial robot interactions.

This study aims to examine the relationship between employees’ psychological contract breach and two types of voice behavior based on the social exchange theory. Additionally, the study explores the role of globally responsible business leadership in buffering the negative impacts of psychological contract breach on voice.

Survey data was collected from Chinese full-time employees and the final sample size is 337. Partial least squares structural equation modeling was used to test the hypotheses.

Findings indicate that psychological contract breach (PCB) has a positive and significant impact on employee aggressive voice behavior (AVB), while its relationship with constructive voice behavior (CVB) is not significant. Furthermore, globally responsible business leadership (GRBL) weakens the negative relationship between PCB and CVB, while strengthens the positive relationship between PCB and AVB.

The findings assist organizations in better recognizing the detrimental consequences of psychological contract breach. Second, the findings serve as a reminder to managers of the benefits of displaying globally responsible business leadership. Third, managers should recognize the complexities of globally responsible business leadership.

First, this study sheds new light on the impact of PCB on employees’ desirable and undesirable proactive behaviors by investigating how and when psychological contract breach affects two types of voice behavior. Second, the moderating role of GRBL further enriches our understanding of how to buffer negative effects of PCB and the desirable function of GRBL. Third, this study enriches the social exchange theory by investigating whether the leader−employee relationship will compensate for the failure of organization−employee relationship.

Microenterprises (MEs) are vital to the growth and prosperity of economies around the world. All levels of society, from universities to national governments, have collaborated to improve the chances of survival and future growth of these businesses. The threat to life is serious, and unless concerted action is taken, the situation will spiral out of control. Policymakers and business leaders must work together to address the sustainability crisis. The study, therefore, set out to determine how various entrepreneurial skills (such as creativity, collaboration, networking, and risk-taking) affect the long-term viability of MEs. The overall objective of the study was to determine the importance of innovative problem-solving, collaboration, networking, and willingness to take calculated risks of microentrepreneurs for the long-term success of their businesses. A total of 274 microentrepreneurs in rural areas of the Ancash region of Peru were surveyed in the grocery, hardware, clothing, and food service sectors. The survival of the MEs was tested on four dimensions: innovation, leadership, networking, and risk-taking. According to the results, MEs managers can increase their longevity by cultivating creative skills, strengthening leadership as a key to business sustainability and survival, maximizing the use of networks to gain a market advantage and expand their customer base, and employing calculated risk-taking.

The purpose of this paper is to study the thermal behavior of radial porous fin surrounded by water-base copper nanoparticles under the influence of radiation.

In order to optimize the response variable, the authors perform sensitivity analysis with the aid of response surface methodology (RSM). Moreover, this study enlightens the applications of artificial neural networks (ANN) for predicting the temperature gradient. The governing modeled equations are firstly non-dimensionalized and then solved with the aid of Runge–Kutta fourth order together with the shooting method in order to guess the initial conditions.

Numerical results are analyzed and presented in the form of tables and graphs. This study reveals that the temperature of the fin is decreasing as the wet porous parameter increases (m₂) and the temperature for 10% concentration of nanoparticles are higher than 5 and 1%. Physical parameters involved in the study are analyzed and processed through RSM. It is come to know that sensitivity of temperature gradient to radiative parameter (Nr) and convective parameter (Nc) is positive and negative to dimensionless ambient temperature (θ_a). Furthermore, after ANN training it can be argued that the established model can efficiently be used to predict the temperature gradient over a radial porous fin for the copper-water nanofluid flow.

To the best of our knowledge, only a few attempts have been made to analyze the thermal behavior of radial porous fin surrounded by copper-based nanofluid under the influence of radiation and convection.

The research analyzes the influence of three environmental triggers, i.e. awareness, concern and knowledge on environmental attachment and green motivation that affect tourists' pro-environmental behavior in the Pakistan’s tourism industry. Furthermore, this study has analyzed the moderating role of moral obligation concerning environmental attachment and green motivation on tourists' pro-environmental behavior.

Data were gathered via a structured questionnaire by 237 local (domestic) tourists of Pakistan. Furthermore, the data were examined by employing SmartPLS.

Findings demonstrate that all three environmental triggers have a positive and significant relationship with environmental attachment and green motivation. Accordingly, environmental attachment and green motivation promote tourists' pro-environmental behavior. Furthermore, the moderating role of moral obligations has also been incorporated in the study. The finding reveals a strong and positive relationship among environmental attachment and tourists' pro-environmental behaviors during high moral obligations. In contrast, moral obligations do not moderate association between green motivation and tourists' pro-environmental behavior. Therefore, competent authorities should facilitate tourists to adopt environmentally friendly practices; which will ultimately promote pro-environmental behavior.

This study provides useful insights regarding the role of tourism in fostering environmental attachment and green motivation that sequentially influence tourist pro-environmental behavior. Secondly, this research has employed moral obligations as a moderator to identify the changes in tourists’ pro-environmental behavior based on individuals' ethical considerations. Hence, the study provides an in-depth insight into tourists' behavior. Lastly, the present research offers effective strategies for the tourism sector and other competent authorities to increase green activities that can embed the importance of the environment among individuals.

This study aims to investigate the effect of abusive supervision on employees’ creativity through the mediating role of job insecurity and the moderating role of subordinate gender in Indonesia.

Data were collected from various sources using online recruitment methods. The abusive supervision scale, job insecurity scale and employee creativity scale were the three measures in this study. Participants completed a three-wave data collection procedure using an online survey platform. After removing participants with incomplete and careless responses, the final data set contained 515 usable responses.

The results suggested that the negative effect of abusive supervision on employees’ creativity was mediated by job insecurity, and employees’ gender moderated this adverse effect. Gender roles shaped how employees respond to their leader’s hostile behaviours. In Indonesia, abusive supervision increased employees’ job insecurity and consequently reduced their creativity. However, the damage was more profound for the male employees than the female employees.

Gender role theory and perspectives are essential in explaining leader–employee interactions and must be included in leadership strategies. Also, support and resources must be provided equally for both male and female employees. However, more attention must be given to male employees to ensure their security working in organisations. Finally, some interventions are necessary to mitigate the effect of abusive supervision.

This study offers insight into how male and female employees, in a traditional gender role culture like Indonesia, respond to their leader’s abusive behaviours.

The purpose of this paper is to examine the combined effects of thermal radiation and magnetic field of molybdenum disulfide nanofluid in a channel with changing walls. Water is considered as a Newtonian fluid and treated as a base fluid and MoS₂ as nanoparticles with different shapes (spherical, cylindrical and laminar). The main structures of partial differential equations are taken in the form of continuity, momentum and energy equations.

The governing partial differential equations are converted into a set of nonlinear ordinary differential equations by applying a suitable similarity transformation and then solved numerically via a three-stage Lobatto III-A formula.

All obtained unknown functions are discussed in detail after plotting the numerical results against different arising physical parameters. The validations of numerical results have been taken into account with other works reported in literature and are found to be in an excellent agreement. The study reveals that the Nusselt number increases by increasing the solid volume fraction for different shapes of nanoparticles, and an increase in the values of wall expansion ratio α increases the velocity profile f′(η) from lower wall to the center of the channel and decreases afterwards.

In this paper, a numerical method was utilized to investigate the influence of molybdenum disulfide (MoS₂) nanoparticles shapes on MHD flow of nanofluid in a channel. The validity of the literature review cited above ensures that the current study has never been reported before and it is quite new; therefore, in case of validity of the results, a three-stage Lobattoo III-A formula is implemented in Matlab 15 by built in routine “bvp4c,” and it is found to be in an excellent agreement with the literature published before.

There has been substantial research on branding globally. However, there is a dearth of studies empirically investigating branding strategies during the pandemic to mitigate COVID-19 effects on the airline industry. The paper considers three factors which are brand familiarity, brand communication and brand reputation to develop the brand trust of customers and that ultimately influence their brand preferences.

The study is based on self-administrative surveys as 450 questionnaires were spread, received 339 responses and a total of 301 questionnaires were selected for data analysis by structural-based modeling after the deletion of outliers and partially filled questionnaires. The data was collected through purposive sampling from Malaysian airports.

The findings confirm the relationship of brand communication, brand familiarity and brand reputation to brand trust and brand preference through mediation and directly except direct relationship of brand familiarity to brand preference. The study is limited to the provided dataset of surveys. The present study couldn't interview respondents which can be done by future studies and also effects of COVID-19 can be examined on related industries or through comparative studies among countries.

The present study is the first to investigate the effects of COVID-19 on airline brands and explored the strategies to respond to crises. The study is one of the rare studies that consider branding strategies to the uplift airline industry and mitigate post-pandemic effects from the airline sector.