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Article
Publication date: 19 March 2021

Abdelraheem M. Aly and Ehab Mahmoud Mohamed

This study aims to illustrate the impacts of the motion of circular cylinders on the natural convection flow from variable heated partitions inside the X-shaped cavity…

Abstract

Purpose

This study aims to illustrate the impacts of the motion of circular cylinders on the natural convection flow from variable heated partitions inside the X-shaped cavity filled with Al2O3-water nanofluid. A partial layer of a homogeneous/heterogeneous porous medium is located in the top area of the X-shaped cavity.

Design/methodology/approach

Three different cases of the porous media including homogeneous, horizontal heterogeneous and vertical heterogeneous porous media were considered. Three different thermal conditions of the embedded circular cylinders including hot, cold and adiabatic conditions are investigated. An incompressible scheme of smoothed particle hydrodynamics (ISPH) method is modified to compute the non-linear partial differential equations of the current problem. Two variable lengths of the left and right sides of the X-shaped cavity have a high-temperature Th and a low-temperature Tc, respectively. The other wall parts are adiabatic. The numerical simulations are elucidating the dependence of the heat transfer and fluid flow characteristics on lengths of hot/cold source Lh, porous cases, Darcy parameter, thermal conditions of the embedded circular cylinders and solid volume fraction.

Findings

Overall, an increment in length of hot/cold source leads to augmentation on the temperature distributions and flow intensity inside the X-shaped cavity. The hot thermal condition of the circular cylinder augments the temperature distributions. The homogeneous porous medium slows down the flow speed in the top porous layer of the X-shaped cavity. The average Nusselt number decreases as Lh increases.

Originality/value

ISPH method simulated the motion of circular cylinders in the X-shaped cavity. The X-shaped cavity is saturated with a partial layer porous medium. It is found that an increase in hot source length augments the temperature and fluid flow. ISPH method can easily handle the motion of cylinders in the X-shaped cavity. Different thermal conditions of cylinders can change the temperature distributions in X-cavity.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 31 no. 5
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 27 November 2020

Abdelraheem M. Aly and Ehab Mahmoud Mohamed

The purpose of this study is to use an incompressible smoothed particle hydrodynamics (ISPH) method for simulating buoyancy ratio and magnetic field effects on double…

Abstract

Purpose

The purpose of this study is to use an incompressible smoothed particle hydrodynamics (ISPH) method for simulating buoyancy ratio and magnetic field effects on double diffusive natural convection of a cooper-water nanofluid in a cavity. An open pipe is embedded inside the center of a cavity, and it is occupied by solid particles.

Design/methodology/approach

The dimensionless governing equations in Lagrangian form were solved by ISPH method. Two different thermal conditions were considered for the solid particles. The actions of the solid particles were tracked inside a cavity. The effects of Hartman parameter, Rayleigh number, nanoparticles volume fraction and Lewis number on features of heat and mass transfer and flow field were tested.

Findings

The results showed that the buoyancy ratio changes the directions of the solid particles diffusion in a cavity. The hot solid particles were raised upwards at aiding mode (N > 0) and downwards at an opposing mode (N < 0). A comparison is made with experimental and numerical simulation results, and it showed a well agreement.

Originality/value

Novel studies for the impacts of buoyancy ratio on the diffusion of solid particles embedded in an open pipe during double-diffusive flow were conducted.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 31 no. 6
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 27 September 2021

Abdelraheem M. Aly, Noura Alsedais and Hakan F. Oztop

The purpose of this study is to use the incompressible smoothed particle hydrodynamics method to examine the influences of a magnetic field on the double-diffusive…

Abstract

Purpose

The purpose of this study is to use the incompressible smoothed particle hydrodynamics method to examine the influences of a magnetic field on the double-diffusive convection caused by a rotating circular cylinder with paddles within a square cavity filled by a nanofluid.

Design/methodology/approach

The cavity is saturated by two wavy layers of non-Darcy porous media with a variable amplitude parameter. The embedded circular cylinder with paddles carrying T_h and C_h is rotating around the cavity center by a uniform circular velocity.

Findings

The lineaments of nanofluid velocity and convective flow, as well as the mean of Nusselt and Sherwood numbers, are represented below the variations on the frequency parameter, amplitude parameter of the wavy porous layers, Darcy parameter, nanoparticles parameter, Hartmann number and Ryleigh number. The performed simulations showed the role of paddles mounted on circular cylinders for enhancing the transmission of heat and mass within a cavity. The wavy porous layers at the lower Darcy parameter are playing as a blockage for the nanofluid flow within the porous area. Increasing the concentration of the nanoparticles to 6% reduces the maximum flow speed by 8.97% and maximum streamlines |ψ|max by 10.76%. Increasing Hartmann number to 100 reduces the maximum flow speed by 65.83% and |ψ|max by 75.54%.

Originality/value

The novelty of this work is to examine the effects of an inclined magnetic field and rotating novel shape of a circular cylinder with paddles on the transmission of heat/mass in the interior of a nanofluid-filled cavity saturated by undulating porous medium layers.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 32 no. 3
Type: Research Article
ISSN: 0961-5539

Keywords

Article
Publication date: 4 April 2016

Ehab Alshamaileh, Mazen Al-Sulaibi, Ahmad Al-Khawaldeh, Mansour H. Almatarneh, Dina El-Sabawi and Aiman Al-Rawajfeh

The current status of nanotechnology research and development in Jordan is analyzed. In recent years, Jordanian institutions demonstrated considerable interest in the…

Abstract

Purpose

The current status of nanotechnology research and development in Jordan is analyzed. In recent years, Jordanian institutions demonstrated considerable interest in the development and production of nanotechnology. Here the purpose of this paper is to provide detailed information about the status of nanotechnology in Jordan in terms of several factors that influence selectivity in nanotechnology and the number of published peer-reviewed research articles.

Design/methodology/approach

Several factors that influence selectivity in nanotechnology and the number of published peer-reviewed research articles were analyzed. A detailed analysis of the collected data reveals that the number of publications, citations, and patents is highly dependent on the amount of research fund.

Findings

The development in nanotechnology is associated with presence and accessibility of sensitive laboratory equipment. The nanotechnology research output in Jordan is still lower than it should be due to the lack of necessary laboratory infrastructure. This is due to the insufficient funds allocated to scientific research, the restrictive access to available instruments and the bureaucracy of some governmental departments. Compared to some developed countries, Jordan is noticeably behind in developing a nanotechnology system of research and industry. It will take time as well as technical and financial resources in order to achieve an advanced level in the field of nanotechnology in Jordan. Nevertheless, many Jordanian researchers are doing their best and are producing some good research articles.

Research limitations/implications

The many applications to the same approach.

Practical implications

Time and publications’ resources.

Social implications

Peer cooperation.

Originality/value

First comprehensive review ever. A base for researchers and decision makers.

Details

World Journal of Science, Technology and Sustainable Development, vol. 13 no. 2
Type: Research Article
ISSN: 2042-5945

Keywords

Article
Publication date: 14 June 2022

Achraf Haddad

The purpose of this research is to compare the board quality's (BQ) impacts on the financial performance (FP) of conventional and Islamic banks (IBs) after the Subprime…

Abstract

Purpose

The purpose of this research is to compare the board quality's (BQ) impacts on the financial performance (FP) of conventional and Islamic banks (IBs) after the Subprime financial crisis. The main reason is to help financial stakeholders choose the best performing and most appropriate bank type with its engagement based on the BQ index.

Design/methodology/approach

Based on the existing gap in previous researches and by using the GLS method (Generalized Least Squares method), the author compared the BQ's impacts on the FP of conventional and IBs. Settings of the FP and BQ were collected from 30 countries located on 4 continents. Two equal samples were tested; each of them is composed of 112 banks. The author concentrated only on the banks that have published regularly the banks' annual reports over the period 2010–2018.

Findings

Cylindrical panel results revealed that in conventional banks (CBs), the BQ has negatively affected banks' FP, while in IBs the BQ's impacts on the banks’' FP is ambiguous. Nevertheless, the positive impacts are more significant on the IBs' FP than the negative impacts on the IBs' FP.

Practical implications

The main practical contribution is the identification and distinction between the impacts of board determinants' quality on the shareholders' profits in the case of conventional and IBs. Hence, conventional or IBs which have a bad BQ will generate less FP and will be classified as a lender of bankruptcy danger for the bank customer. Besides, whatever the bank type, in a financial stable period, good BQ positively influences FP and provides a good impression to stakeholders. Otherwise, FP indicates that the banks suffer from the weaknesses of the board quality determinants.

Originality/value

Returning to the finance and banking governance literature, the author's article provides the first conditional and demonstrative analysis that detailed a logical comparative process to analyze the correlation between the board determinants' quality and the financial performance of conventional and IBs. However, previous research has always discussed the main role of the board as an internal governance mechanism on the FP separately in each bank type.

Details

Journal of Accounting in Emerging Economies, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 2042-1168

Keywords

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