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Article
Publication date: 1 May 2001

H.M. El‐Hawary

In this paper a spline approximation of deficiency 3 and a step of length 3h method is proposed to approximate the solution of the problem and its derivatives. The Falkner‐ Skan…

420

Abstract

In this paper a spline approximation of deficiency 3 and a step of length 3h method is proposed to approximate the solution of the problem and its derivatives. The Falkner‐ Skan equation has been solved through the use of the shooting technique for handling the problem when the conditions imposed are of boundary‐value rather than an initial‐value type for different values of its parameters. Comparisons are made between the data resulting from the proposed method and those obtained by others.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 11 no. 3
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 7 February 2024

Nancy Sobh, Nagla Elshemy, Sahar Nassar and Mona Ali

Due to herbs and plants’ therapeutic properties and simplicity of availability in nature, humans have used them to treat a variety of maladies and diseases since ancient times…

212

Abstract

Purpose

Due to herbs and plants’ therapeutic properties and simplicity of availability in nature, humans have used them to treat a variety of maladies and diseases since ancient times. Later, as technology advanced, these plants and herbs gained significant relevance in some industries due to their suitable chemical composition, abundant availability and ease of access. Aegle marmelos is a species of plant that may be found in nature. Yet, little or very little literature was located on the coloration behavior of this plant’s leaves. This study aims to focus on the effect of different parameters on the extraction of colorant from Aegle marmelos leaves.

Design/methodology/approach

Some factors that affected on the extraction processes were examined and found to have significant impacts on the textile dyeing such as the initial dye concentration, extracted temperature, extracted bath pH and extracted time were all changed to see how they affected color extraction. The authors report a direct comparison between three heating methods, namely, microwave irradiation (MWI), ultrasonic waves (USW) and conventional heating (CH). The two kinetic models have been designed (pseudo-first and pseudo-second orders) in the context of these experiments to investigate the mechanism of the dyeing processes for fabrics under study. Also, the experimental data were analyzed according to the Langmuir and Freundlich isotherms.

Findings

From the result, it was discovered these characteristics were found to have a substantial effect on extraction efficiency. Temperature 90°C and 80°C when using CH and USW, respectively, while at 90% watt when using MWI, period 120 min when using CH as well as USW waves, while 40 min when using MWI, and pH 4, 5 and 10 for polyamide, wool and cotton, respectively, were the optimal extraction conditions. Also, the authors can say that wool gives a higher absorption than the other fabric. Additionally, MWI provided the best color strength (K/S) value, and homogeneity, at low temperatures reducing the energy and time consumed. The coloring follows the order: MWI > USW > CH. The adsorption isotherm of wool could be well fitted by Freundlich isotherm when applying CH and USW as a heating source, while it is well fitted by the Langmuir equation in the case of MWI. In the study, it was observed that the pseudo-first-order kinetic model fits better the experimental results of CH with a constant rate K1 = −0.000171417 mg/g.min, while the pseudo-second-order kinetic model fits better the experimental results of absorption of both MWI (K2 = 38.14022572 mg/g.min) and USW (K2 = 12.45343554 mg/g.min).

Research limitations/implications

There is no research limitation for this work. Dye was extracted from Aegle marmelos leaves by applying three different heating sources (MWI, ultrasonic waves [USWW] and CH).

Practical implications

This work has practical applications for the textile industry. It is concluded that using Aegle marmelose leaves can be a possible alternative to extract dye from natural resource by applying new technology to save energy and time and can make the process greener.

Social implications

Socially, it has a good impact on the ecosystem and global community because the extracted dye does not contain any carcinogenic materials.

Originality/value

The work is original and contains value-added products for the textile industry and other confederate fields.

Details

Pigment & Resin Technology, vol. 54 no. 1
Type: Research Article
ISSN: 0369-9420

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Article
Publication date: 18 September 2007

Anati Ali, Norsarahaida Amin and Ioan Pop

The purpose of this paper is to study the unsteady boundary layer flow of a micropolar fluid past a circular cylinder which is started impulsively from rest.

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Abstract

Purpose

The purpose of this paper is to study the unsteady boundary layer flow of a micropolar fluid past a circular cylinder which is started impulsively from rest.

Design/methodology/approach

The nonlinear partial differential equations consisting of three independent variables are solved numerically using the 3D Keller‐box method.

Findings

Numerical solutions for the velocity profiles, wall skin friction and microrotation profiles are obtained and presented for various values of time t and material parameter K with the boundary condition for microrotation n=0 (strong concentration of microelements) and n=1/2 (weak concentration of microelements). The results are presented along the points on the cylinder surface, starting from the forward to the rear stagnation point, for small time up to the time when the boundary layer flow separates from the cylinder.

Originality/value

It is believed that this is the first paper that uses the 3D Keller‐box method to study the unsteady boundary layer flow of micropolar fluids. In the last four decades, there has been overhelming interest shown by researchers in micropolar fluids and still many problems are unsolved. The paper shows not only the fundamental importance of this problem, but also the implications for situations of practical interest.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 17 no. 7
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 15 May 2024

Alshaymaa Foudah, May Tarek, Sarah Essam, Mostafa El Hawary, Kareem Adel and Mohamed Marzouk

This study aims to thoroughly explore and visualize the trends and developments of digital twin (DT) literature in the construction field while revealing future research…

172

Abstract

Purpose

This study aims to thoroughly explore and visualize the trends and developments of digital twin (DT) literature in the construction field while revealing future research directions for further exploration and exploitation.

Design/methodology/approach

The research follows a three-stage methodology. First, the bibliographic data is acquired using the Web of Science database. Second, the bibliometric methods are defined to include co-authorship analysis, citation analysis, keywords co-occurrence, thematic mapping while the software tools include MS Excel, VOSviewer and Biblioshiny. Third, analysis and findings include yearly DT publication output, influential DT publications, leading DT contributors, top DT sources and science mapping of DT literature.

Findings

This study identifies top-cited DT publications (35 out of 320) in terms of citations score, local citations score and document average citations per year. Furthermore, the key contributors with respect to authors (58 out of 1147), organizations (55 out of 427) and countries (19 out of 51) are recognized in terms of productivity, influence, activeness and scientific value. Similarly, the major publishing sources (24 out of 58) are identified using the same measures. Regarding science mapping, the DT domain comprises four research frontiers, namely, deep learning and smart city, internet of things and blockchain, DT and building information modeling and machine learning and asset management.

Originality/value

Through a mixed-review strategy, this study introduces a comprehensive analysis of DT literature while avoiding the subjectivity/cognitive bias of traditional review approaches. Moreover, it illuminates the promising and rising DT themes for new/seasoned researchers, institutions, editorial boards and funding agencies.

Details

Construction Innovation , vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 1471-4175

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Book part
Publication date: 19 December 2016

Mohammad Ashraful Ferdous Chowdhury, Mohammad Shoyeb, Chowdhury Akbar and Md. Nazrul Islam

The purpose of this study is to examine the effect of risk sharing and non-risk sharing instruments on both the profitability of Islamic banks and the economic growth of the…

Abstract

Purpose

The purpose of this study is to examine the effect of risk sharing and non-risk sharing instruments on both the profitability of Islamic banks and the economic growth of the country. This study also aims to improve the profit and loss sharing-based asset growth of Islamic banks.

Methodology/approach

The data for this study are obtained from the annual reports of all Islamic banks from Bangladesh using Bank scope database and annual report for the period of 1983–2014. The research uses Autoregressive Distributive Lag approach.

Findings

The findings reveal that risk sharing instruments are positively related to profitability and the economic growth of the country. This study also finds that non-risk sharing instruments play a predominant role in the profitability of the Islamic bank but are negatively related to the economic growth of the country.

Research implications

Banks and other financial institutions need to pay greater attention to systemic risk created by risk transfer and apply risk sharing methods of financing more vigorously than has hitherto been the case.

Originality/value

This study will also contribute to the literature as relatively few Islamic financial literatures deal with the relationship between equity financing and profitability which may make a strong contribution to the area of Islamic finance.

Details

Advances in Islamic Finance, Marketing, and Management
Type: Book
ISBN: 978-1-78635-899-8

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Article
Publication date: 1 April 2019

Arulraj Rajendran and Kumarappan Narayanan

This paper aims to optimally plan distributed generation (DG) and capacitor in distribution network by optimizing multiple conflicting operational objectives simultaneously so as…

112

Abstract

Purpose

This paper aims to optimally plan distributed generation (DG) and capacitor in distribution network by optimizing multiple conflicting operational objectives simultaneously so as to achieve enhanced operation of distribution system. The multi-objective optimization problem comprises three important objective functions such as minimization of total active power loss (Plosstotal), reduction of voltage deviation and balancing of current through feeder sections.

Design/methodology/approach

In this study, a hybrid configuration of weight improved particle swarm optimization (WIPSO) and gravitational search algorithm (GSA) called hybrid WIPSO-GSA algorithm is proposed in multi-objective problem domain. To solve multi-objective optimization problem, the proposed hybrid WIPSO-GSA algorithm is integrated with two components. The first component is fixed-sized archive that is responsible for storing a set of non-dominated pareto optimal solutions and the second component is a leader selection strategy that helps to update and identify the best compromised solution from the archive.

Findings

The proposed methodology is tested on standard 33-bus and Indian 85-bus distribution systems. The results attained using proposed multi-objective hybrid WIPSO-GSA algorithm provides potential technical and economic benefits and its best compromised solution outperforms other commonly used multi-objective techniques, thereby making it highly suitable for solving multi-objective problems.

Originality/value

A novel multi-objective hybrid WIPSO-GSA algorithm is proposed for optimal DG and capacitor planning in radial distribution network. The results demonstrate the usefulness of the proposed technique in improved distribution system planning and operation and also in achieving better optimized results than other existing multi-objective optimization techniques.

Details

International Journal of Energy Sector Management, vol. 13 no. 1
Type: Research Article
ISSN: 1750-6220

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Article
Publication date: 27 May 2014

Jiyang Dai, Jin Ying and Chang Tan

– The purpose of this paper is to present a novel optimization approach to design a robust H-infinity controller.

145

Abstract

Purpose

The purpose of this paper is to present a novel optimization approach to design a robust H-infinity controller.

Design/methodology/approach

To use a modified particle swarm optimization (PSO) algorithm and to search for the optimal parameters of the weighting functions under the circumstance of the given structures of three weighting matrices in the H-infinity mixed sensitivity design.

Findings

This constrained multi-objective optimization is a non-convex, non-smooth problem which is solved by a modified PSO algorithm. An adaptive mutation-based PSO (AMBPSO) algorithm is proposed to improve the search accuracy and convergence of the standard PSO algorithm. In the AMBPSO algorithm, the inertia weights are modified as a function with the gradient descent and the velocities and positions of the particles.

Originality/value

The AMBPSO algorithm can efficiently solve such an optimization problem that a satisfactory robust H-infinity control performance can be obtained.

Details

Engineering Computations, vol. 31 no. 4
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 12 June 2017

Zayyad Abdul-Baki and Ahmad Bukola Uthman

This paper aims to argue that the current environment in which the Islamic banking system is situated is not ideal for the system’s pursuance of its socioeconomic ideals, thus…

1053

Abstract

Purpose

This paper aims to argue that the current environment in which the Islamic banking system is situated is not ideal for the system’s pursuance of its socioeconomic ideals, thus necessitating the system’s shift from pursuing falah to maximizing profits.

Design/methodology/approach

The paper theorizes and conceptualizes this shift from falah to profit maximization using two complementary theories – systems theory and institutional theory – to prove that such a shift is not unexpected. The paper further adopts a dialectical analysis that is somewhat historical to analyse the shift.

Findings

The measure of the Islamic banks’ performance in terms of their social ideals is misplaced, as the environment in which they currently operate does not support such goals. Thus, stemming from the theoretical base, the Islamic banks’ pursuance of profit maximization instead of falah should not be unexpected. The paper concludes that despite the unfavorable environment, the social ideals of the Islamic banking system may still be met, to an extent, through investment in microfinance and awqaf.

Research limitations/implications

The paper adopts document analysis for sourcing data majorly from prior studies. Hence, the authors do not conclude that the analysis herein is applicable to all Islamic banks. Secondly, as the authors could not get a complete historical account of the Islamic banking system’s development, some aspects of the dialectical analysis – contradiction and change – have been discussed in a general fashion.

Practical implications

The need for Islamic banks in the current environment, especially for the Muslim population, cannot be over emphasized; however, the achievement of falah given this current environment may be daunting.

Originality/value

The current analyses of the shift of Islamic banks from pursuing falah to pursuing profit maximization are not well-defined, as they lack a proper theorization of the challenges faced by Islamic banks. This paper fills this gap.

Details

Journal of Islamic Accounting and Business Research, vol. 8 no. 3
Type: Research Article
ISSN: 1759-0817

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Article
Publication date: 24 September 2019

Amal AlAbbad, M. Kabir Hassan and Irum Saba

The purpose of this paper is to study whether the characteristics of the Shariah Supervisory Board (SSB) can influence the risk-taking behaviors of Islamic banks.

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Abstract

Purpose

The purpose of this paper is to study whether the characteristics of the Shariah Supervisory Board (SSB) can influence the risk-taking behaviors of Islamic banks.

Design/methodology/approach

The data on governance were collected from 70 Islamic banks’ annual reports across 18 countries for the period from 2000 to 2011 to investigate the relationship between SSB’s characteristics including size, busyness and foreign board and the Islamic banks’ risk activities.

Findings

The size of SSB and the proportion of busy board in SSB positively and significantly influence Islamic banks’ asset return and insolvency risks. Foreign members are more effective in monitoring banks’ Shariah compliance. Further analysis provides some evidence that most of the findings on the associations between the SSB structure and bank risk are derived from countries in the Gulf Cooperation Council where Shariah governance is ruled internally at the bank level.

Practical implications

There is a need for better Shariah board characteristics in place that complement with other governance mechanisms to well comprehend the main purpose of Islamic banks.

Originality/value

SSB board busyness and foreign characteristics appear to influence the risk-taking behaviors of Islamic banks.

Details

International Journal of Islamic and Middle Eastern Finance and Management, vol. 12 no. 4
Type: Research Article
ISSN: 1753-8394

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Article
Publication date: 1 April 2019

Narinder Kumar and Ashwani Kumar

The purpose of this paper is to analyze annual energy expenditure in the presence of non-linear load and substation voltage harmonics in distribution systems. Economic assessment…

67

Abstract

Purpose

The purpose of this paper is to analyze annual energy expenditure in the presence of non-linear load and substation voltage harmonics in distribution systems. Economic assessment of non-sinusoidal energy is a challenging task that involves complex computations of harmonic load powers and harmonic line losses.

Design/methodology/approach

The paper evaluates fundamental and non-sinusoidal components of electrical energy by applying backward/forward sweep technique in distorted distribution systems. This work involves harmonic power computations at the substation by including harmonic losses occurring in various lines of the distribution system.

Findings

The paper found that annual energy expenditure significantly depends upon the non-linear load, supply voltage harmonics and type of tariff structure considered in the distribution system. Impact of individual harmonic orders on the energy billing is also assessed.

Originality/value

The paper concludes that considering harmonic distortions in the distribution system analysis would help electricity regulators formulate adequate pricing structures, which would further generate appropriate economic signals for electricity utility and the consumers.

Details

International Journal of Energy Sector Management, vol. 13 no. 1
Type: Research Article
ISSN: 1750-6220

Keywords

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