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The purpose of this paper is to develop a model that facilitates the evaluation and selection processes of curtain wall systems used in office buildings.

A comprehensive literature review and interviews with local experts were conducted to identify common types of curtain wall systems used in office buildings and their selection criteria. A questionnaire was designed and completed using multi-criteria decision-making techniques through face-to-face meetings with consultants in the Eastern Province of Saudi Arabia. The proposed model was implemented in prototype software as a proof of concept.

The results revealed that fire resistance scored the highest weighting of all the criteria. Furthermore, precast concrete cladding panels were found to be the best system for use in office buildings located in the Eastern Province of Saudi Arabia. The model validation reveals that the score for any curtain wall system varies depending on the nature of the project and that the prioritisation of criteria can vary from one practitioner to another.

The model captures the knowledge of professionals who are experts in the prioritisation of criteria for selecting curtain wall systems. The research design presented expands the boundaries of knowledge of the relevant literature, through demonstrating a conceptual framework incorporating different techniques into a computerised model. It has practical implications through presenting a systematic procedure for developing and adopting a computerised decision-making tool, which aligns experts’ professional practice and requirements, for use in selecting fragmented options.

This study aims to investigate experimentally and numerically the thermal analysis of a wavy diverging-converging corrugated enclosure, partitioned into two parts under the effect of magnetohydrodynamic (MHD) natural convection. The left part was filled with Al₂O₃/C₂H₆O₂ nanofluid, while the right part was Al₂O₃/C₂H₆O₂ saturated by a porous medium, featuring a corrugated cylinder at the center. This system is relevant to many engineering applications. Key factors affecting thermal performance, such as nanofluid volume fraction, Darcy number, Hartmann number, inclination angle of MHD and Rayleigh number, were analyzed. This study evaluated the impact of these parameters on stream function, average Nusselt number and isothermal lines under three heat source scenarios: heating the corrugated cylinder, heating the magnetic source and heating the nanofluid, porous media and corrugated walls.

The main governing equations for the nanofluid flow are mass, momentum and heat transfer, while the porous media are modeled using the Darcy–Brinkmann model. These governing equations are transformed into a dimensionless form and solved numerically using COMSOL 6.0 based on the finite-element method. Dynamic viscosity, density and thermal conductivity equations are used to calculate the properties of the nanofluid at different volume concentrations.

The results showed that increasing the Rayleigh number (Ra) and Darcy number (Da) increased the Nusselt number by 55%, indicating enhanced heat transfer. A vertical magnetic source (γ = 90°) further improved thermal performance. Conversely, thermal performance decreased with increasing Hartmann number (Ha). The highest Nusselt number was observed when the heat source was applied to the corrugated cylinder, followed by the right side with nanofluid–porous contact and was lowest for the left side with nanofluid contact. Experimental data demonstrated that the presence of a magnetic field can significantly increase the temperature, thereby enhancing heat transfer by natural convection, particularly when the heat source is applied in the region of nanofluid–porous contact.

The primary originality of this work lies in the use of a novel design featuring a diverging-converging structure with a wavy wall. In addition, it uses two types of fluids simultaneously, dividing the enclosure into two sections: the right side contains nanofluid mixed with a porous medium, while the left side is filled with nanofluid only. The system also includes a corrugated cylinder at its center with four undulations. The position of the heat source significantly influences heat dissipation. Therefore, three different positions were examined: heating the cylinder at a constant temperature, heating the left side of the enclosure and heating the right side.

Design issues are one of the factors contributing to waste production in the Ghanaian construction industry (GCI). Design for adaptability (DfA) is a construction approach that provides buildings with adaptive capabilities during the design phase. It facilitates easy modification, with no or limited demolition, waste reduction, sustainable construction and circularity. However, as to whether design professionals operating in the GCI are aware of this concept and its benefits and whether they consider some of its practices in the designs they produce are something that is yet to be ascertained. Therefore, this study aims to investigate the awareness and engagement of DfA practices among design professionals in the GCI.

The study adopted a quantitative research approach to retrieve responses from 236 design professionals (i.e. architects and civil/structural engineers) via survey questionnaires. The data retrieved from the respondents were analyzed using both descriptive and inferential statistical tests.

The findings revealed that the design professionals were moderately aware of the concept of DfA. Notwithstanding this moderate level of awareness, the design professionals’ frequency of engagement in DfA practices was high, and factors such as profession, experience and type of firms they worked in, among others, did not influence their level of engagement in DfA practices.

This study pioneers research on DfA implementation in the GCI. It highlights design professionals’ awareness and engagement in adaptability practices, thereby revealing gaps in knowledge, encouraging sustainable design and promoting resilience in architecture, which could ultimately contribute to a future-proofing built environment in Ghana.

This study aims to satisfy the thermal management of gallium nitride (GaN) high-electron mobility transistor (HEMT) devices, microchannel-cooling is designed and optimized in this work.

A numerical simulation is performed to analyze the thermal and flow characteristics of microchannels in combination with computational fluid dynamics (CFD) and multi-objective evolutionary algorithm (MOEA) is used to optimize the microchannels parameters. The design variables include width and number of microchannels, and the optimization objectives are to minimize total thermal resistance and pressure drop under constant volumetric flow rate.

In optimization process, a decrease in pressure drop contributes to increase of thermal resistance leading to high junction temperature and vice versa. And the Pareto-optimal front, which is a trade-off curve between optimization objectives, is obtained by MOEA method. Finally, K-means clustering algorithm is carried out on Pareto-optimal front, and three representative points are proposed to verify the accuracy of the model.

Each design variable on the effect of two objectives and distribution of temperature is researched. The relationship between minimum thermal resistance and pressure drop is provided which can give some fundamental direction for microchannels design in GaN HEMT devices cooling.

This paper aims at examining the co-movement dependent regime and causality relationships between conventional and Islamic returns for emerging, frontier and developed markets from November 2008 to August 2020.

First, the authors used the Markov-switching autoregression (MS–AR) model to capture the regime-switching behavior in the stock market returns. Second, the authors applied the Markov-switching regression and vector autoregression (MS-VAR) models in order to study, respectively, the co-movement and causality relationship between returns of conventional and Islamic indexes across market states.

Results show the presence of two different regimes for the three studied markets, namely, stability and crisis periods. Also, the authors found evidence of a co-movement relationship between the conventional and Islamic indexes for the three studied markets whatever the regime. For the Granger causality, it is proved only for emerging and developed markets and only during the stability regime. Finally, the authors conclude that Islamic indexes can act as diversifiers, or safe-haven assets are not strongly supported.

This paper is the first study that examines the co-movement and the causal relationship between conventional and Islamic indexes not only across different financial markets' regimes but also during the COVID-19 period. The findings may help investors in making educated decisions about whether or not to add Islamic indexes to their portfolios especially during the recent outbreak.