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This paper concerns the analytical investigation of the GO-water nanofluid flow in a semi-porous channel. The Similarity Berman’s transformation is employed to convert the governing partial differential equations of a steady laminar flow of an electrically conducting fluid in a two dimensional channel. Reconstruction of Variational Iteration Method (RVIM) has been used to obtain the expressions for velocity fields.

Graphs are sketched and discussed for various parameters, especially the effect of the expansion ratio on velocity fields. The results indicated that the Reynolds number, Hartmann number and solid volume fraction have strong effect on velocity boundary layer thickness.

The purpose of this paper is to study the laminar boundary layer flow between a stationary nonporous disk and a porous rotating disk, both being immersed in large amount of fluid.

The governing nonlinear momentum equations in cylindrical polar coordinates together with relevant boundary conditions are reduced to a system of coupled nonlinear ordinary differential equations (NODEs) using similarity transformations. The resulting coupled NODEs are solved using computer-extended series solution and homotopy analysis method.

The analytical solutions are explicitly expressed in terms of recurrence relation for determining the universal coefficients. The nature and location of singularity which restricts the convergence of series is analyzed by using Domb–Sykes plot. Reversion of series is used for the improvement of series. The region of validity of series is extended for much larger values of Reynolds number (R), i.e. R = 6 to 15.

The resulting solutions are compared with earlier works in the literature and are found to be in good agreement.

The purpose of this paper is to re-examine the assumptions implicit in Leveque’s approximation, and the variation of the temperature and the thickness of the boundary layer were illustrated using the developed solution. The analytical solutions are then checked against numerical solution programming by FORTRAN code obtained via using Runge–Kutta fourth-order (RK4) method. Finally, other important thermal results obtained from this analysis, such as approximate Nusselt number in the thermal entrance region, was discussed in detail. After that, the analytical results of the present paper are validated with certain previous investigations which were found in the specialized literature.

By defining a similarity variable, the governing equations are reduced to a dimensionless equation with an analytic solution in the entrance region. This paper gives justification for the similarity variable via scaling analysis, details the process of converting to a similarity form and presents a similarity solution. The calculation methodology for numerical resolution is based on the RK4 technique.

The profiles of the solutions are provided from which the authors infer that the numerical and exact solutions agreed very well. Another result that the authors obtained from this paper is the number of Nusselt in the thermal entrance region for which a parametric study was carried out and discussed well for the impact of scientific contribution.

The novelty of this paper is the application of the RK4 with a step size control, as a sequential numerical method of a ODEs system compared with the exact similarity solution of the thermal boundary layer problem.

Fluorocarbon (FC) gas, which contributes to the ozone depletion and global warming, is commonly used especially in the refrigeration and air conditioning (RAC) equipment. In Malaysia, lifecycle management of FC gas is still lacking at all stages, especially at the downstream level (maintenance, service, recycle, recovery, and destruction). Thus, the aim of this study is to assess the level of awareness of local stakeholders and consumers regarding FC gas management. Furthermore, the level of awareness among the consumers has been identified based on their educational background. Two sets of questionnaires were developed based on the dichotomous question types (yes/no) and were distributed to local stakeholders and consumers by using convenience sampling in two different programmes. The data were statistically analysed using IBM SPSS software. Findings demonstrate that, in contrast to consumers, local stakeholders have high level of awareness in every section. Remarkably, all non-engineering respondents have a low level of awareness about FC gas management. As a result, capacity building for consumers and service maintenance personnel who are heavily involved in middle steam and downstream lifecycle FC gas management is needed.

The dynamics and effects of interconnected risks among construction organisations tend to be overlooked across the Malaysian public project supply chains, making them highly vulnerable to supply chain disruptions. This study aims to investigate this dynamism by assessing the supply chain’s critical vulnerabilities and capabilities that formulate the level of resilience in handling disruptive events in construction projects.

A comprehensive questionnaire survey was conducted with 105 construction professionals from two groups of respondents, the public and private organisations that work in public projects to identify their current vulnerabilities and capabilities. Data were analysed and compared using the Mann–Whitney U and Kruskal–Wallis tests.

The findings revealed that the top five critical vulnerability factors of the supply chain include political or regulatory changes, market pressures, management, financial and strategic vulnerability. Further comparisons highlighted that the public organisations faced significantly higher political threats compared to the private organisations whilst the private organisations faced significant market pressures. The survey also shows that despite the private organisations’ high capability in financial strength, the public organisations’ financial vulnerability has destabilised the entire supply chain.

This study presents the construction supply chain’s vulnerabilities in a layered framework approach that can provide managers a new perspective on the dynamics of the cascading impacts of these vulnerabilities when observed through several layers of supply chains.

The competition is increasing every moment for the organizations and hence organizations are putting their best possible efforts to compete. This chapter is designed with the objective to explore various HR practices that can contribute in achieving the total quality management (TQM) in business. The basis for the study is taken from the aspects of competition that are cost reduction, differentiation and innovation. The extensive literature review from Scopus, J-gate, EBSCO and Springer databases are studied to integrate various aspects of TQM and HR practices that inculcate the competitive advantage for organizations. The framework may be developed for the reference to introduce and implement HR practices and manage TQM in the organization. The study may also help the professionals in designing the relevant HR practices for more value to the organizations. The linkage between various factors of the study may be helpful for the academicians and corporate organizations.

This study aims to get the essential data of the solubility and diffusion coefficient of gas in jet fuel for appropriately designing a kind of on-board inert gas generation system.

A test apparatus based on pressure–decay method was constructed to measure solubility and diffusion coefficient of gas in liquid. The test apparatus and method were verified via measurement of solubility and diffusion of CO₂ in the pure water.

The solubility of CO₂ and O₂ in RP-3 jet fuel with the temperature from 253 to 313 K under three various pressures were measured and compared with theoretical value calculated by a relative density method provided in the standard of ASTM D2780-92, and the deviation is within 10 per cent. The diffusion coefficients of CO₂ and O₂ in RP-3 jet fuel are determined by monitoring the gas pressure in a hermetic cell versus time with the temperature from 253 to 333 K. The measured diffusivity-temperature relation can be well fitted through the Arrhenius equation for engineering applications. The obtained correlation can be used to predict the diffusion coefficient of CO₂ and O₂ in RP-3 jet fuel under a wide temperature range.

The semi-empirical correlation of solubility and diffusion coefficient in RP-3 jet fuel obtained from the experimental data could be used to support the design of an inert gas generation system.

There are no essential data of solubility and diffusion of CO₂ and O₂ in RP-3 jet fuel; therefore, it is fatal if the quantity and rate of mass transfer of CO₂ and O₂ in RP-3 jet fuel must be assessed, e.g. during the design of green on-board inert gas generation system.

This study aims to seek a new economic and environmental protection fuel tank inerting method.

The principle that serves as the basis for the cooling inerting process is described, the workflow of the cooling inerting system is designed, the mathematical model of the cooling inerting system is established, and the important performance changes of cooling inerting in the flight package line and the influence of key parameters on it are simulated by using Modelica software.

The results show that the cooling inerting system can be turned on to quickly reduce the vapour concentration in the gas phase in the fuel space and reduce the temperature below the flammability limit. Within a certain range of pumping flow, the inerting effect is more obvious when the pumping flow is larger. Simply running the cooling inerting system on the ground can remain the tank in an inert state throughout the flight envelope.

However, cooling inerting is suitable for models with fewer internal heat sources. An excessive number of internal heat sources will lead to inerting failure.

This study provides theoretical support for the feasibility of cooling inerting. Cooling inerting does not require engine air, and the cooling is mainly accomplished with air, which places a small load on the cooling system and has a much lower cost than the airborne hollow fibre film inerting technology widely used at present. It is a promising new inerting technology.

The development of written accuracy among learners of English as a Second Language (ESL) has always been a primary concern for ESL teachers and researchers in Applied Linguistics and Second Language Acquisition (SLA). While a vast body of research has examined written corrective feedback on students’ written products, few studies have focused on the development of written accuracy among Arabic speaking learners of English using automated feedback tools. This case study first examined the level of written accuracy of Bahraini learners of English in their second year at a higher education institute, highlighting the frequency of errors influenced by their first language (Arabic). The course following this first stage included a significant component of automated feedback on students’ writing; and this study explored the impact that the use of these feedback tools had on learners’ writing in English, tracking development over the course of an academic semester. A corpus of students’ initial writings and subsequent revisions was analysed to identify whether there was an improvement in the accuracy of students’ texts; and students’ perceptions were elicited.

ﻟط ﺎﻟ ﻣﺎ ﻛﺎ ن ﺗ طوﯾ ر اﻟدﻗﺔ ﻓ ﻲ ﻣﮭﺎ رة اﻟ ﻛﺗﺎﺑﺔ ﺑﯾ ن ﻣﺗ ﻌﻠ ﻣ ﻲ اﻟﻠ ﻐﺔ ا ﻹﻧ ﺟﻠﯾ زﯾﺔ ﻛﻠ ﻐﺔ ﺛﺎﻧﯾﺔ اﻟ ﺷـ ﻐ ل اﻟ ﺷـﺎ ﻏل ﻟ ﻣﻌﻠ ﻣ ﻲ اﻟﻠ ﻐﺔ ا ﻹﻧﺟ ﻠﯾ زﯾﺔ واﻟﺑﺎﺣ ﺛﯾ ن ﻓ ﻲ اﻟﻠ ﻐو ﯾﺎ ت اﻟ ﺗ ط ﺑﯾﻘﯾ ﺔ و ا ﻛﺗ ﺳ ـﺎ ب اﻟﻠ ﻐﺔ اﻟ ﺛﺎﻧﯾ ﺔ. ﻓ ﻲ ﺣ ﯾ ن أ ن ﻣ ﺟ ﻣو ﻋ ﺔ ﻛﺑﯾ ر ة ﻣ ن ا ﻷ ﺑ ﺣ ﺎ ث ﻗد د ر ﺳ ـ ت ﻣ ﻼ ﺣ ظ ﺎ ت ﺗ ﺻ ـ ﺣ ﯾ ﺣ ﯾ ﺔ ﺧ ط ﯾ ﺔ ﻋ ﻠ ﻰ ﻛﺗﺎﺑﺎ ت اﻟط ﻼ ب ، ﻓﻘ د رﻛز ت د را ﺳ ــﺎ ت ﻗﻠﯾﻠ ﺔ ﻋ ﻠ ﻰ ﺗ ط وﯾ ر اﻟ دﻗﺔ ﻓ ﻲ ﻣﮭﺎ رة اﻟ ﻛﺗﺎﺑ ﺔ ﺑﯾ ن ﻣﺗ ﻌﻠ ﻣ ﻲ اﻟﻠ ﻐﺔ ا ﻹ ﻧ ﺟ ﻠﯾ زﯾ ﺔ اﻟﻧﺎ ط ﻘﯾ ن ﺑﺎﻟ ﻌرﺑﯾ ﺔ ﺑﺎ ﺳ ــﺗ ﺧ دا م أدو ا ت اﻟ ﺗ ﻐذﯾ ﺔ ا ﻻ ﺳ ـــﺗ ر ﺟ ﺎ ﻋ ﯾ ﺔ ﻋ ﺑ ر ا ﻹ ﻧﺗ ر ﻧ ت . ﺗ ﺗ ﻧ ﺎ و ل د ر ا ﺳ ـ ـ ﺔ ا ﻟ ﺣ ﺎ ﻟ ﺔ ھ ذ ه أ و ﻻً ﻣ ﺳ ـ ـ ﺗ و ى ا ﻟ د ﻗ ﺔ ا ﻟ ﻣ ﻛ ﺗ و ﺑ ﺔ ﻟ ﻠ ﻣ ﺗ ﻌ ﻠ ﻣ ﯾ ن ا ﻟ ﺑ ﺣ ر ﯾ ﻧ ﯾ ﯾ ن ﻟ ﻠ ﻐ ﺔ ا ﻹ ﻧ ﺟ ﻠ ﯾ ز ﯾ ﺔ ﻓ ﻲ ﺳـ ﻧﺗ ﮭم اﻟﺛﺎﻧﯾ ﺔ ﻓ ﻲ ﻣؤﺳـ ﺳـ ﺔ ﻟﻠﺗ ﻌﻠﯾم اﻟﻌﺎﻟ ﻲ ، ﻣﻊ اﻟﺗ رﻛﯾ ز ﻋﻠ ﻰ ﺗﻛرا ر أ ﺧطﺎ ء اﻟﺗدا ﺧل ﺑﯾ ن اﻟﻠ ﻐﺔ ا ﻻوﻟ ﻰ واﻟﺛﺎﻧﯾﺔ. ﺛم ﺗ ﺳـﺗﻛ ﺷـ ف اﻟد را ﺳـ ﺔ ﺗﺄﺛﯾ ر أ دو ا ت اﻟ ﻣ ﻼﺣظﺎ ت ﻋﺑ ر ا ﻹﻧﺗ رﻧ ت ﻋﻠ ﻰ ﻛﺗﺎﺑﺔ اﻟ ﻣﺗ ﻌﻠ ﻣﯾ ن ﺑﺎﻟﻠ ﻐﺔ ا ﻹﻧ ﺟﻠﯾ زﯾﺔ ﻛﻠ ﻐﺔ ﺛﺎ ﻧﯾ ﺔ، وﺗ ﺗﺑ ﻊ اﻟﺗ طور ﺧﻼل اﻟﻔ ﺻ ـــ ل اﻟ د را ﺳـــ ﻲ. ﯾﺗ ﺿ ـــ ﻣ ن ا ﻟ ﺗ د ﺧ ل ا ﻟ ﻣ ط ﺑ ق ﻟ ﺗ ﺣ ﺳـ ﯾ ن ﺗ ﻧ ﻣ ﯾ ﺔ ﻣ ﮭ ﺎ ر ا ت ا ﻟ ﻣ ﺗ ﻌ ﻠ ﻣ ﯾ ن ﻣ ﻛ و ﻧًﺎ ﻣ ﮭ ﻣً ﺎ ﻟ ﻠ ﺗ ﻌ ﻠ ﯾ ق ﻋ ﺑ ر ا ﻹ ﻧ ﺗ ر ﻧ ت . ﻗ ﺎ ﻣ ت ا ﻟ د ر ا ﺳـ ﺔ ﺑ ﺗ ﺣ ﻠ ﯾ ل ﻣ ﺟ ﻣ و ﻋ ﺔ ﻣ ن ا ﻟ ﻛ ﺗ ﺎ ﺑ ﺎ ت ا ﻷ و ﻟ ﯾ ﺔ وا ﻟ ﻣرا ﺟﻌﺎ ت اﻟ ﻼﺣ ﻘﺔ ﻟﻠط ﻼ ب ، ﺑﺎﻹ ﺿ ﺎﻓﺔ إﻟ ﻰ ﻣر ا ﺟ ﻌﺎ ت اﻟ ﻧ ظ ر ا ء، ﻟﺗﺣ دﯾد ﻣﺎ إ ذا ﻛﺎ ن ھﻧﺎ ك ﺗ ﺣ ﺳ ن ﻓ ﻲ دﻗﺔ اﻟﻧ ﺻ و ص اﻟﻣﻛﺗ و ﺑ ﺔ ﻟﻠط ﻼ ب .

While much of the world’s attention has focused on the human cost of COVID-19, the economic cost caused by the pandemic has also had and is having a strong impact on European economies, energy markets and the environment. This chapter first investigates the social effects of the pandemic, with particular emphasis on the ratio of deaths to cases in different countries, which may reflect the quality of health care, vaccine management and quality of life in regions of the world, especially in relation to the European continent. Secondly, this chapter examines the main effects that the pandemic has had over time on the European Union economy, especially on trade, transport, tourism, gross domestic product (GDP), unemployment, the inflation rate and the savings rate of Europeans. Thirdly, the chapter analyses the effects of the pandemic on the demand, production and prices of fossil and renewable energies in Europe, as well as the effect on the transition from fossil to renewable energies. Fourthly and finally, the chapter analyses the distortion generated by the pandemic on carbon dioxide emissions into the atmosphere and the momentary improvement of the environment. Against this backdrop, this chapter summarises the impact of COVID-19 on the European Union economy, energy, and environment.