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This paper aims to establish a lattice Boltzmann (LB) method for solid-liquid phase transition (SLPT) from the pore scale to the representative elementary volume (REV) scale. By applying this method, detailed information about heat transfer and phase change processes within the pores can be obtained, while also enabling the calculation of larger-scale SLPT problems, such as shell-and-tube phase change heat storage systems.

Three-dimensional (3D) pore-scale enthalpy-based LB model is developed. The computational input parameters at the REV scale are derived from calculations at the pore scale, ensuring consistency between the two scales. The approaches to reconstruct the 3D porous structure and determine the REV of metal foam were discussed. The implementation of conjugate heat transfer between the solid matrix and the solid−liquid phase change material (SLPCM) for the proposed model is developed. A simple REV-scale LB model under the local thermal nonequilibrium condition is presented. The method of bridging the gap between the pore-scale and REV-scale enthalpy-based LB models by the REV is given.

This coupled method facilitates detailed simulations of flow, heat transfer and phase change within pores. The approach holds promise for multiscale calculations in latent heat storage devices with porous structures. The SLPT of the heat sinks for electronic device thermal control was simulated as a case, demonstrating the efficiency of the present models in designing and optimizing SLPT devices.

A coupled pore-scale and REV-scale LB method as a numerical tool for investigating phase change in porous materials was developed. This innovative approach allows for the capture of details within pores while addressing computations over a large domain. The LB method for simulating SLPT from the pore scale to the REV scale was given. The proposed method addresses the conjugate heat transfer between the SLPCM and the solid matrix in the enthalpy-based LB model.

The proposed model aims to consider the flying hours as a criterion to initiate maintenance operation. Based on this condition, aircraft must be checked before flying hours threshold is met. After receiving maintenance service, the model ignores previous flying hours and the aircraft can keep on flying until the threshold value is reached again. Moreover, the model considers aircraft age and efficiency to assign them to flights.

The aircraft maintenance routing problem (AMRP), as one of the most important problems in the aviation industry, determines the optimal route for each aircraft along with meeting maintenance requirements. This paper presents a bi-objective mixed-integer programming model for AMRP in which several criteria such as aircraft efficiency and ferrying flights are considered.

As the solution approaches, epsilon-constraint method and a non-dominated sorting genetic algorithm (NSGA-II), including a new initializing algorithm, are used. To verify the efficiency of NSGA-II, 31 test problems in different scales are solved using NSGA-II and GAMS. The results show that the optimality gap in NSGA-II is less than 0.06%. Finally, the model was solved based on real data of American Eagle Airlines extracted from Kaggle datasets.

The authors confirm that it is an original paper, has not been published elsewhere and is not currently under consideration of any other journal.

This paper aims to investigate whether paid work activity (PWA) experience of students from five emerging economies is related to academic results and self-assessment of possessed entrepreneurial traits. Additionally, the authors verify the relationship between obtaining work experience and the willingness to start own business among students.

Participants included 3,631 students of the first level of higher education at six universities in five countries (Bulgaria, Latvia, Lithuania, Poland and Ukraine). A survey questionnaire was used which included questions on the previous work experience, paid work during university studies, the assessment of competencies related to entrepreneurship and the assessment of the desirability of entrepreneurship as a career choice.

Findings indicate that students who engaged in PWA before studies are more likely to do it during studies. PWA during studies is related to perceiving oneself as a worse-performing student, but also to the perception of oneself as an entrepreneurial person. No such relationship was found for the PWA experience before entering the university. It was also found that students are likely to start their businesses after obtaining work experience.

Practical implications pertain to the role of the contemporary academic institutions that should consider their approach to enabling students’ PWA and teaching them how to engage in it for the benefit of their own and the societies to which they belong. It is argued that it may be particularly essential in emerging economies.

The correlates of PWA of students have been underexplored. This paper allows broadening the current understanding of this phenomenon. The authors investigated its relationship with feeling entrepreneurial and academic achievements among young people from five emerging economies, which provides valuable insights for policymakers and educational institutions. It is argued that such insights may be particularly essential in emerging economies. Additionally, the authors contribute to advancing two theories that have not been extensively used in the entrepreneurial context: expectancy theory and social learning theory of career development.

This review aims to give a critical view of the wheel/rail high frequency vibration-induced vibration fatigue in railway bogie.

Vibration fatigue of railway bogie arising from the wheel/rail high frequency vibration has become the main concern of railway operators. Previous reviews usually focused on the formation mechanism of wheel/rail high frequency vibration. This paper thus gives a critical review of the vibration fatigue of railway bogie owing to the short-pitch irregularities-induced high frequency vibration, including a brief introduction of short-pitch irregularities, associated high frequency vibration in railway bogie, typical vibration fatigue failure cases of railway bogie and methodologies used for the assessment of vibration fatigue and research gaps.

The results showed that the resulting excitation frequencies of short-pitch irregularity vary substantially due to different track types and formation mechanisms. The axle box-mounted components are much more vulnerable to vibration fatigue compared with other components. The wheel polygonal wear and rail corrugation-induced high frequency vibration is the main driving force of fatigue failure, and the fatigue crack usually initiates from the defect of the weld seam. Vibration spectrum for attachments of railway bogie defined in the standard underestimates the vibration level arising from the short-pitch irregularities. The current investigations on vibration fatigue mainly focus on the methods to improve the accuracy of fatigue damage assessment, and a systematical design method for vibration fatigue remains a huge gap to improve the survival probability when the rail vehicle is subjected to vibration fatigue.

The research can facilitate the development of a new methodology to improve the fatigue life of railway vehicles when subjected to wheel/rail high frequency vibration.

Based on the principle of equality, individuals with disabilities have the right to equal job opportunities and career advancements and to actively participate in the economy like other members of society. This study aims to provide an integrated description of discriminatory occupational practices and behaviours that individuals with disabilities face. This study followed the descriptive analytical approach to achieve the objectives. A questionnaire was used for data collection purposes.

The target population for this study was male and female employees with disabilities working in the Jordanian Government sector for the years 2019–2022 in all governorates of Jordan. The sample method used was purposive-convenient random sampling, and the size of the sample valid for statistical analysis was n = 1,043. Using the Statistical Package for Social Sciences (v26), a number of statistical tests were conducted to infer the features of the researched phenomenon.

This study found an overall moderate level (mean = 2.76) of practices and behaviours of job discrimination against individuals with disabilities in the Jordanian public sector. All proposed practices and behaviours were at moderate levels of agreement, with the highest discriminatory behaviours being in the areas of training and learning opportunities (2.88), followed by job performance evaluation (2.84), work leave and vacation (2.75), integration and social participation (2.74), career advancement and promotion (2.73) and, last, the distribution of tasks and responsibilities (2.61). Furthermore, it was found that there are significant differences in the levels of discriminatory practices and behaviours towards people with physical disabilities, individuals with visual impairments and psychological disabilities, new employees at work and those with a low level of education. In addition, employees at higher administrative levels (manager, deputy/assistant manager and head of department/division) and workers in the southern and central governorates are exposed to the highest levels of discrimination.

Lack of data: There is often a lack of reliable and comprehensive data on employees with disabilities, making it difficult for researchers to accurately study and understand the experiences of this population. Stigma and discrimination: People with disabilities often face stigma and discrimination, which can make it challenging for researchers to engage with them and collect accurate information.

Moreover, it was found that the main agencies to which cases of discriminatory practices towards individuals with disabilities working in the Jordanian public sector are reported are the direct managers/supervisors (n = 381), the ministry to which the institution/department belongs (n = 278) and the Higher Council for the Rights of Persons with Disabilities (n = 261).

Supporting social inclusion: Employment can provide a sense of purpose, identity and social inclusion for people with disabilities, which can have a positive impact on their disabilities and overall quality of life. Improving diversity and inclusion: The inclusion of employees with disabilities can contribute to a more diverse and inclusive workplace, where all employees feel valued and respected.

This study found that discriminatory practices against employees with disabilities in the Jordanian public sector were largely because of a lack of awareness of reporting mechanisms and negative attitudes towards individuals with disabilities. This study proposes solutions such as raising awareness among non-disabled employees, implementing penalties for discriminatory behaviour and updating legislation for the rights of individuals with disabilities.

This paper examines the career progression of women auditors working in auditing firms in Tanzania and the strategies employed by women auditors to cope with the masculine nature of audit firms.

Data were collected through semi-structured, in-depth interviews with current and former female and male auditors in two auditing firms. A thematic approach to the analysis is adopted.

The study reveals that career progression of women auditors studied is constrained by gender-related barriers such as motherhood, pregnancy, maternity leave and limited coaching and networking, as well as household and caring responsibilities. These barriers are facilitated by the patriarchal system, which regards women as wives and mothers rather than professional workers. As a result, women auditors balanced work and family responsibilities by employing various coping strategies including establishing informal network organization, hiring nannies, living with family members, enrolling children to boarding schools and lobbying in the allocation of audit assignments. Despite employing these strategies, very few women reach top positions in audit firms in Tanzania.

The findings reveal a need for wider engagement on the role of women and men in society, particularly to address the gender-related barriers faced by women in the accountancy profession.

Most previous studies of gender in the accountancy profession have focused on Western contexts. This is one of few to examine the phenomenon in an African context.

The expansion of bike-sharing enterprises has led to a series of social problems, and due to the high breakage rate and high recycling cost of bike sharing, enterprises are reluctant to maintain them. Therefore, government regulation does play a leading role in maintaining bike sharing. This study’s purpose is to investigate how the government should regulate the bike-sharing enterprises that maintain bicycles.

Firstly, the authors assume that there is only one bike-sharing enterprise and establish a game model that the government regulates the enterprise. Furthermore, the authors extend the model to the case that there are two competing enterprises in the market. Finally, through numerical analysis, the influence of various factors on the government strategy and revenue is analyzed.

The authors find that the regulatory probability of two enterprises are regulated by the government is larger than that of one enterprise. When two bike-sharing enterprises compete without government regulation, both will choose the non-self-discipline strategy, thus falling into the Prisoner's Dilemma. If the government regulates them, then both enterprises will choose the self-discipline strategy. Finally, through numerical analysis, it is found that the self-discipline behavior of bike-sharing enterprises is related to the government regulatory probability, the cost of self-discipline, the probability of being reported and the penalties. Interestingly, the cost of government regulation will not affect the regulation probability of government.

This research provides a theoretical reference for the government to make the regulation strategies of bike sharing and achieve the sustainable development of bike sharing.

This research provides a theoretical reference for the government to make the regulation strategies of bike sharing and achieve the sustainable development of bike sharing.

Distribution network design involves a set of strategic decisions in supply chains because of their long-term impacts on the total logistics cost and environment. To incorporate a trade-off between financial and environmental aspects of these decisions, this paper aims to determine an optimal location, among candidate locations, of a new logistics center, its capacity, as well as optimal network flows for an existing distribution network, while concurrently minimizing the total logistics cost and gas emission. In addition, uncertainty in transportation and warehousing costs are considered.

The problem is formulated as a fuzzy multiobjective mathematical model. The effectiveness of this model is demonstrated using an industrial case study. The problem instance is a four-echelon distribution network with 22 products and a planning horizon of 20 periods. The model is solved by using the min–max and augmented ε-constraint methods with CPLEX as the solver. In addition to illustrating model’s applicability, the effect of choosing a new warehouse in the model is investigated through a scenario analysis.

For the applicability of the model, the results indicate that the augmented ε-constraint approach provides a set of Pareto solutions, which represents the ideal trade-off between the total logistics cost and gas emission. Through a case study problem instance, the augmented ε-constraint approach is recommended for similar network design problems. From a scenario analysis, when the operational cost of the new warehouse is within a specific fraction of the warehousing cost of third-party warehouses, the solution with the new warehouse outperforms that without the new warehouse with respective to financial and environmental objectives.

The proposed model is an effective decision support tool for management, who would like to assess the impact of network planning decisions on the performance of their supply chains with respect to both financial and environmental aspects under uncertainty.

Particles are of the controlled release delivery systems. Also, topically applied olive oil has a protective effect against ultraviolet B (UVB) exposure. Due to its sensitivity to oxidation, various studies have investigated the production of olive oil particles. The purpose of this study was to use chitosan and sodium alginate as the vehicle polymers for olive oil.

The gelation method used to prepare the sodium alginate miliparticles containing olive oil and particles were coated with chitosan. Morphology and size, zeta potential, infrared spectrum of olive oil miliparticles, encapsulation efficiency and oil release profile were investigated. Among 12 primary fabricated formulations, formulations F₅ (olive oil loaded alginate miliparticles) and F₁₁ (olive oil loaded alginate miliparticles + chitosan coat) were selected for further evaluations.

The size of the miliparticles was in the range of 1,100–1,600 µm. Particles had a spherical appearance, and chitosan coat made a smoother surface according to the scanning electron microscopy. The zeta potential of miliparticles were −30 mV for F₅ and +2.7 mV for F₁₁. Fourier transform infrared analysis showed that there was no interaction between olive oil and other excipients. Encapsulation efficiency showed the highest value of 85% in 1:4 (olive oil:alginate solution) miliparticles in F₁₁. Release study indicated a maximum release of 68.22% for F₅ and 60.68% for F₁₁ in 24 h (p-value < 0.016). Therefore, coating with chitosan had a marked effect on slowing the release of olive oil. These results indicated that olive oil in various amounts can be successfully encapsulated into the sodium-alginate capsules cross-linked with glutaraldehyde.

To the best of the authors’ knowledge, no study has used chitosan and sodium alginate as the vehicle polymers for microencapsulation of olive oil.

This paper aims to investigate the hydrodynamic instability properties of a mixed convection flow of nanofluid in a porous channel.

The treated single-phase nanofluid is a suspension consisting of water as the working fluid and alumina as a nanoparticle. The anisotropy of the porous medium and the effects of the inclination of the magnetic field are highlighted. The effects of viscous dissipation and thermal radiation are incorporated into the energy equation. The eigenvalue equation system resulting from the stability analysis is processed numerically by the spectral collocation method.

Analysis of the results in terms of growth rate reveals that increasing the volume fraction of nanoparticles increases the critical Reynolds number. Parameters such as the mechanical anisotropy parameter and Richardson number have a destabilizing effect. The Hartmann number, permeability parameter, magnetic field inclination, Prandtl number, wave number and thermal radiation parameter showed a stabilizing effect. The Eckert number has a negligible effect on the growth rate of the disturbances.

Linear stability analysis of Magnetohydrodynamics (MHD) mixed convection flow of a radiating nanofluid in porous channel in presence of viscous dissipation.