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Article
Publication date: 22 October 2018

Ali Mohammad Rashidi, Mehrad Paknezhad and Tooraj Yousefi

This study aims to clarify the relationship between inclination angle of hot surface of CPU and its temperature in absence and presence of aluminum foam as a cooling system. It…

224

Abstract

Purpose

This study aims to clarify the relationship between inclination angle of hot surface of CPU and its temperature in absence and presence of aluminum foam as a cooling system. It proposes application of the artificial neural [multi-layer perceptron (MLP) and radial basis function] networks and adaptive neuron-fuzzy inference system (ANFIS) to predict interface temperature of central processing unit (CPU)/metal foam heat sink.

Design/methodology/approach

To provide a consistent set of data, the surface of an aluminum cone with and without installing Duocel aluminum foam was heated in a natural convection using an electrical resistor. The hot surface temperature was measured using five K-type thermocouples (±0.1°C). To develop the predictive models, ambient temperature, input power and inclination angle are taken as input which varied from 23°C to 32°C, 4 to 20 W and 0° to 90°, respectively. The hot surface temperature is taken as the output.

Findings

The results show that in the presence of foam, the hot surface temperature was less sensitive to the variations of angle, and the maximum enhancement of the heat transfer coefficient was 23 per cent at the vertical position. Both MLP network and ANFIS are comparable, but the values predicted by MLP network are in more conformity with the measured values.

Originality/value

The effect of metal foam on the inclination angle/hot surface temperature dependence is identified. The optimum angle is clarified. The applicability of the MLP networks to predict interface temperature of CPU/heat sink is approved.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 28 no. 12
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 13 February 2023

SeyedAhmad SeyedAlinaghi, Behnam Farhoudi, Elnaz Shahmohamadi, Mehrnaz Rasoolinejad, Maliheh Hasannezhad, Mohammad Rasool Rashidi, Omid Dadras, Ali Moradi, Zohal Parmoon, Hooman Ebrahimi and Ali Asadollahi-Amin

Hepatitis C is one of the major health issues in both developed and developing countries. Hepatitis C virus (HCV) infection is more common in prisoners than in the general…

86

Abstract

Purpose

Hepatitis C is one of the major health issues in both developed and developing countries. Hepatitis C virus (HCV) infection is more common in prisoners than in the general population. The purpose of this study was to determine the prevalence of HCV and its associated risk factors in Iranian male prisoners in Tehran.

Design/methodology/approach

In this cross-sectional study, the authors investigated the frequency and risk factors of hepatitis C infection among male prisoners in the Great Tehran Prison. Information on risk factors including the length of imprisonment, previous history of imprisonment, history of drug injection, history of tattooing, history of piercing, history of high-risk sex and family history of hepatitis C were extracted from patients’ records. To evaluate HCV status, blood samples were collected and tested.

Findings

In this study, 179 participants were included. Nine participants (5.0%, 95% CI, 2.3-9.3) were positive for hepatitis C. HCV infection was not significantly associated with age, marital status, education, previous history of imprisonment, length of imprisonment, piercing and high-risk sex; however, there was a significant association between a history of tattooing and a history of injecting drug use and Hepatitis C.

Originality/value

The prevalence of hepatitis C among male prisoners in Great Tehran Prison was 5% in this study, similar to recent studies on prisoners in Tehran. A history of drug injections as well as tattooing were the most important risk factors for hepatitis C in male prisoners.

Details

International Journal of Prisoner Health, vol. 19 no. 4
Type: Research Article
ISSN: 1744-9200

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Article
Publication date: 4 December 2017

Aurang Zaib, Mohammad Mehdi Rashidi, Ali J. Chamkha and Krishnendu Bhattacharyya

This paper aims to peruse the influence of second law analysis for electrically conducting fluid of a Casson nanofluid over a wedge. For activation energy, a modified Arrhenius…

208

Abstract

Purpose

This paper aims to peruse the influence of second law analysis for electrically conducting fluid of a Casson nanofluid over a wedge. For activation energy, a modified Arrhenius function is used.

Design/methodology/approach

The highly non-linear governing equations are developed using similarity transformations and then computed numerically via Keller–Box method.

Findings

The influences of emerging parameters on velocity, temperature distribution and concentration of nanoparticle are explained and presented via graphs and tables. Also, the behavior of fluid flow is investigated through the coefficient of skin friction, Nusselt and Sherwood numbers. Results reveal that the velocity profile enhances due to increasing Casson parameter and magnetic parameter, whereas the temperature distribution and concentration of nanoparticle decrease with larger vales of Casson parameter. It is inspected that the concentration boundary layer increases due to activation energy and decreases due to reaction rate and temperature differences.

Originality/value

The authors believe that all the numerical results are original and significant which are used in biomedicine, industrial, electronics and transportation. The results have not been considered elsewhere.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 27 no. 12
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 6 November 2018

Aurang Zaib, Rizwan Ul Haq, Ali J. Chamkha and Mohammad Mehdi Rashidi

The purpose of this paper is to present an inclusive study of the mixed convective flow involving micropolar fluid holding kerosene/water-based TiO2 nanoparticle towards a…

169

Abstract

Purpose

The purpose of this paper is to present an inclusive study of the mixed convective flow involving micropolar fluid holding kerosene/water-based TiO2 nanoparticle towards a vertical Riga surface with partial slip. The outcomes are confined for opposing and assisting flows.

Design/methodology/approach

Similarity equations are acquired and then worked out numerically by the Keller box technique.

Findings

Impacts of significant parameters on microrotation velocity, temperature distribution, velocity profile together with the Nusselt number and the skin friction are argued with the help of graphs. Two solutions are achieved in opposing flow, while the solution is unique in assisting flow. It is also monitored that the separation of boundary layer delays because of micropolar parameter and accelerates because of volume fraction.

Originality/value

The authors trust that all these results are new and significant for researchers.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 5
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 20 September 2011

Mohammad Mehdi Rashidi and Eemaeel Erfani

The purpose of this paper is to investigate the nano boundary‐layer flows over stretching surfaces with Navier boundary condition. This problem is mapped into the ordinary…

540

Abstract

Purpose

The purpose of this paper is to investigate the nano boundary‐layer flows over stretching surfaces with Navier boundary condition. This problem is mapped into the ordinary differential equation by presented similarity transformation. The resulting nonlinear ordinary differential equation is solved analytically by applying a newly developed method. The authors consider two types of flows: viscous flows over a two‐dimensional stretching surface; and viscous flows over an axisymmetric stretching surface.

Design/methodology/approach

The governing equation is solved analytically by applying a newly developed method, namely the differential transform method (DTM)‐Padé technique that is a combination of the DTM and the Padé approximation. The analytic solutions of the nonlinear ordinary differential equation are constructed in the ratio of two polynomials.

Findings

Graphical results are presented to investigate influence of the slip parameter and the suction parameter on the normal velocity and on the lateral velocity. The obtained solutions, in comparison with the numerical solutions, demonstrate remarkable accuracy. It is predicted that the DTM‐Padé can have wide application in engineering problems especially for boundary‐layer problems.

Originality/value

The resulting nonlinear ordinary differential equation is solved analytically by applying a newly developed method, namely the DTM‐Padé technique that is a combination of the DTM and the Padé approximation. The analytic solutions of the nonlinear ordinary differential equation are constructed in the ratio of two polynomials.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 21 no. 7
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 17 January 2022

Khakan Najaf, Ali Haj Khalifa, Shaher Mohammad Obaid, Abdulla Al Rashidi and Ahmed Ataya

This study aims to look at how financial technology (FinTech) companies adhere to sustainable standards in contrast to their counterparts. Following the validation of its new…

1247

Abstract

Purpose

This study aims to look at how financial technology (FinTech) companies adhere to sustainable standards in contrast to their counterparts. Following the validation of its new sustainability index, this study looks into the impact of sustainability on the stock performance of FinTech companies.

Design/methodology/approach

To efficiently test the hypotheses, sample has been collected from the Bloomberg of all FinTech and non-FinTech companies from the USA. The final sample comprises 1,712 company-year observations over the investigation period 2010–2019. The methodology entails ordinary least squares regressions and generalized panel methods of moments (GMM).

Findings

The results suggest that the developed sustainability index is a valid proxy for sustainability measures and directly relates to stock performance. Besides, the evidence indicates that non-FinTech companies display superior sustainability and stock performance compared to FinTech companies. The present results corroborate with stakeholder theory, which implies that quality sustainability performance will alleviate the agency issue and safeguard the shareholders’ interest.

Research limitations/implications

Despite the fact that it presents the limitation of not considering other dimensions of financial performance, this research is important as it highlights the sustainability practices by the FinTech and non-FinTech companies, offering insights to researchers, policymakers, regulators, financial reports users, investors, environmental union, employees, clients and society.

Originality/value

This paper is novel because it is unique in evaluating the sustainability practices in FinTech and non-FinTech firms.

Details

Competitiveness Review: An International Business Journal , vol. 33 no. 1
Type: Research Article
ISSN: 1059-5422

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Article
Publication date: 25 February 2014

Hany Hassan and Mohammad Mehdi Rashidi

– The paper aims to find an accurate analytic solution (series solution) for the micropolar flow in a porous channel with mass injection for different values of Reynolds number.

993

Abstract

Purpose

The paper aims to find an accurate analytic solution (series solution) for the micropolar flow in a porous channel with mass injection for different values of Reynolds number.

Design/methodology/approach

In this paper, the homotopy analysis method (HAM) with different numbers of unknown convergence-control parameters has been used to derive accurate analytic solution for micropolar flow in a porous channel with mass injection. The possible optimal value of convergence-control parameter determined by minimizing the averaged residual error.

Findings

The results obtained from HAM solution with two parameters are compared with numerical results and that obtained from HAM solution with only one parameter. The results show that this method gives an analytical solution with high order of accuracy with a few iterations. As shown in this paper, by minimizing the averaged residual error, the authors can get the possible optimal value of the convergence-control parameters which may give the fastest convergent series.

Practical implications

The HAM with different numbers of unknown convergence-control parameters can be used to obtain analytic solutions for many problems in sciences and engineering.

Originality/value

This paper fulfils an identified need to evaluate the accurate analytic solution (series solution) of practical problem.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 24 no. 2
Type: Research Article
ISSN: 0961-5539

Keywords

Available. Open Access. Open Access
Article
Publication date: 31 July 2020

Mohammad Mahbubi Ali and Rusni Hassan

Tawarruq (Islamic commodity financing) has evolved as the most ubiquitous concept in Malaysia’s Islamic banking industry. Nevertheless, the extensive use of tawarruq has invoked a…

9621

Abstract

Purpose

Tawarruq (Islamic commodity financing) has evolved as the most ubiquitous concept in Malaysia’s Islamic banking industry. Nevertheless, the extensive use of tawarruq has invoked a number of Sharīʿah (Islamic law) concerns in its practice. This study aims to investigate the Sharīʿah non-compliant (SNC) phenomena in the practice of tawarruq financing in Malaysia.

Design/methodology/approach

This study adopts qualitative research methodology, combining both descriptive and content analysis. A self-administered questionnaire was distributed to 16 Malaysian Islamic commercial banks to unveil the Sharīʿah non-compliance issues in the application of tawarruq in Islamic banks (IBs) in Malaysia.

Findings

The study found that some practices of tawarruq in Malaysia might not comply with the Sharīʿah, mainly due to the improper sequencing of contracts. The study also discovered that IBs adopt different approaches in dealing with SNC events and the income derived therefrom. Finally, the study noted the influence of board of director/management on certain Sharīʿah decisions particularly on the treatment of non-ḥalāl (impermissible) income.

Practical implications

The findings of the study serve as a reference to industry players and regulators in formulating a Sharīʿah non-compliance risk management framework for tawarruq practices.

Originality/value

The survey on SNC issues in tawarruq practice constitutes the first of its kind in the existing literature.

Details

ISRA International Journal of Islamic Finance, vol. 12 no. 2
Type: Research Article
ISSN: 0128-1976

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Article
Publication date: 13 September 2022

Ali Noroozian, Babak Amiri and Mehrdad Agha Mohammad Ali Kermani

Movies critics believe that the diversity of Iranian cinematic genres has decreased over time. The paper aims to answer the following questions: What is the impact of the…

143

Abstract

Purpose

Movies critics believe that the diversity of Iranian cinematic genres has decreased over time. The paper aims to answer the following questions: What is the impact of the continuous cooperation between the key nodes on the audience's taste, uniformity of the cinematic genres and the box office? Is there any relationship between the importance of actors in the actors' network and their popularity?

Design/methodology/approach

In the artistic world, artists' relationships lead to a network that affects individuals' commercial or artistic success and defines the artwork's value. To study the issue that the diversity of Iranian cinematic genres has decreased over time, the authors utilized social network analysis (SNA), in which every actor is considered a node, and its collaboration with others in the same movies is depicted via edges. After preparing the desired dataset, networks were generated, and metrics were calculated. First, the authors compared the structure of the network with the box office. The results illustrated that the network density growth negatively affects box office. Second, network key nodes were identified, their relationships with other actors were inspected using the Apriori algorithm to examine the density cause and the cinematic genre of key nodes, and their followers were investigated. Finally, the relationship between the actors' Instagram follower count and their importance in the network structure was analyzed to answer whether the generated network is acceptable in society.

Findings

The social problem genre has stabilized due to continuous cooperation between the core nodes because network density negatively impacts the box office. As well as, the generated network in the cinema is acceptable by the audience because there is a positive correlation between the importance of actors in the network and their popularity.

Originality/value

The novelty of this paper is investigating the issue raised in the cinema industry and trying to inspect its aspects by utilizing the SNA to deepen the cinematic research and fill the gaps. This study demonstrates a positive correlation between the actors' Instagram follower count and their importance in the network structure, indicating that people follow those central in the actors' network. As well as investigating the network key nodes with a heuristic algorithm using coreness centrality and analyzing their relationships with others through the Apriori algorithm. The authors situated the analysis using a novel and original dataset from the Iranian actors who participated in the Fajr Film Festival from 1998 to 2020.

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Article
Publication date: 3 December 2018

Aurang Zaib, Rizwan Ul Haq, A.J. Chamkha and M.M. Rashidi

The study aims to numerically examine the impact of nanoparticles on an unsteady flow of a Williamson fluid past a permeable convectively heated shrinking sheet.

61

Abstract

Purpose

The study aims to numerically examine the impact of nanoparticles on an unsteady flow of a Williamson fluid past a permeable convectively heated shrinking sheet.

Design/methodology/approach

In sort of the solution of the governing differential equations, suitable transformation variables are used to get the system of ODEs. The converted equations are then numerically solved via the shooting technique.

Findings

The impacts of such parameters on the velocity profile, temperature distribution and the concentration of nanoparticles are examined through graphs and tables. The results point out that multiple solutions are achieved for certain values of the suction parameter and for decelerating flow, while for accelerating flow, the solution is unique. Further, the non-Newtonian parameter reduces the fluid velocity and boosts the temperature distribution and concentration of nanoparticles in the first solution, while the reverse drift is noticed in the second solution.

Practical implications

The current results may be used in many applications such as biomedicine, industrial, electronics and solar energy.

Originality/value

The authors think that the current results are new and significant, which are used in many applications such as biomedicine, industrial, electronics and solar energy. The results have not been considered elsewhere.

Details

World Journal of Engineering, vol. 15 no. 6
Type: Research Article
ISSN: 1708-5284

Keywords

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