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The Impacts of Monetary Policy in the 21st Century: Perspectives from Emerging Economies
Type: Book
ISBN: 978-1-78973-319-8

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Article
Publication date: 6 August 2021

Zhong-Xin Li, Peng Li and Ke-Chao Wang

The purpose of this paper is to propose a fast, accurate and efficient algorithm for assessment of transient behavior of grounding grids buried in horizontal multilayered earth…

62

Abstract

Purpose

The purpose of this paper is to propose a fast, accurate and efficient algorithm for assessment of transient behavior of grounding grids buried in horizontal multilayered earth model considering soil ionization effect.

Design/methodology/approach

The purpose of this paper is to develop a numerical simulation method to calculate the lightning impulse response of the grounding grid buried in a horizontal multilayered earth model. The mathematical model about the hybrid method based on PI basic function belonging to time domain is proposed in the paper; the mode can precisely calculate the lightning current distribution and lightning impulse response to grounding grids buried in horizontal multilayered soil model considering soil ionization effect. To increase computing efficiency, quasi-static complex image method (QSCIM) and its time-domain Green’s function closed form are introduced in the model.

Findings

The hybrid model is rather stable, with the respect to the number of elements used and with excellent convergence rate. In addition, because this mathematical model belongs to the time domain algorithm, it is very powerful for the simulation of soil ionization caused by high amplitude lightning current.

Research limitations/implications

To increase computing efficiency, QSCIM and its time domain Green's function closed form are introduced in the model.

Practical implications

The mathematical model about the hybrid method based on PI basic function can precisely calculate the lightning current distribution and lightning impulse response to grounding grids buried in horizontal multilayered soil model considering the soil ionization effect.

Social implications

Considering the soil ionization effect, the simulation calculation of lightning impulse response of substation grounding grid buried in the actual horizontal multilayered earth can effectively support the scientific and efficient design of lightning protection performance of substation grounding grid.

Originality/value

The hybrid model in time domain is originally developed by the authors and used to precisely calculate the lightning current distribution and lightning impulse response to grounding grids buried in horizontal multilayered soil model considering soil ionization effect. It is simple and very efficient and can easily be extended to arbitrary grounding configurations.

Available. Open Access. Open Access
Article
Publication date: 19 January 2024

Ummi Ibrahim Atah, Mustafa Omar Mohammed, Abideen Adewale Adeyemi and Engku Rabiah Adawiah

The purpose of this paper is to propose a model that will demonstrate how the integration of Salam (exclusive agricultural commodity trade) with Takaful (micro-Takaful – a…

1204

Abstract

Purpose

The purpose of this paper is to propose a model that will demonstrate how the integration of Salam (exclusive agricultural commodity trade) with Takaful (micro-Takaful – a subdivision of Islamic insurance) and value chain can address major challenges facing the agricultural sector in Kano State, Nigeria.

Design/methodology/approach

The study conducted a thorough and critical analysis of relevant literature and existing models of financing agriculture in Nigeria to come up with the proposed model.

Findings

The findings indicate that measures undertaken to address the major challenges fail. In view of this, this study proposed Bay-Salam with Takaful and value chain model to solve a number of challenges such as poor access to financing, poor marketing and pricing, delay, collateral requirement and risk issues in order to avail farmers with easy access to finance and provide effective security to financial institutions.

Research limitations/implications

The paper is limited to using secondary data. Therefore, empirical investigation can be carried out to strengthen the validation of the model.

Practical implications

The study outcome seeks to improve the productivity of the farmers through enhancing their access to finance. This will increase their level of production and provide more employment opportunities. In addition, it will boost financial inclusion, income generation, poverty alleviation, standard of living, food security and overall economic growth and development.

Originality/value

The novelty of this study lies in the integration of classical Bay-Salam with Takaful and value chain and create a unique model structure which the researchers do not come across in any research that presented it in Nigeria.

Details

Islamic Economic Studies, vol. 32 no. 1
Type: Research Article
ISSN: 1319-1616

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Article
Publication date: 8 October 2020

Seyyed Sajjad Sajjadi and Saeed Reza Ostadzadeh

The purpose of this paper is to investigate the ionization and dispersion effects in combination with the inhomogeneity of soil simultaneously on the effective lengths of…

76

Abstract

Purpose

The purpose of this paper is to investigate the ionization and dispersion effects in combination with the inhomogeneity of soil simultaneously on the effective lengths of counterpoise wires.

Design/methodology/approach

Improved multi-conductor transmission line model is used for computing effective length of counterpoise wires considering all aspects of soils.

Findings

The simulation results show that the ionization and dispersion effects simultaneously results in placing the effective length between situations where only one effect is considered. Also, predicting formulae for effective length of counterpoise wires considering all effects are proposed.

Originality/value

A sensitivity analysis on the effective lengths of counterpoise wires considering all aspects of soils is carried out.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering , vol. 39 no. 6
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 20 December 2024

Muhammad Shoaib Farooq and Maimoona Salam

The relationship between corporate-level green entrepreneurial orientation (GEO) and the implementation of cleaner production practices (CPPs) is to a great extent unexplored in…

64

Abstract

Purpose

The relationship between corporate-level green entrepreneurial orientation (GEO) and the implementation of cleaner production practices (CPPs) is to a great extent unexplored in previous literature. This study aims to connect them with the corporate-level green supply chain learning and organizational competitive aggressiveness, presenting a novel interpretation of social ethics and morality in CPPs.

Design/methodology/approach

To thoroughly explore this novel relationship, this study has used PLS-SEM for examining the moderated-mediation of competitive aggressiveness and green supply chain learning.

Findings

Findings based on the data collected from 176 German firms have largely confirmed our propositions. Suggesting that there is a strong positive relationship between corporate level GEO and CPPs. Furthermore, our findings have confirmed that green supply chain learning mediates the macro-level relationship between GEO and CPPs. Moreover, it is also confirmed that the mediation of green supply chain learning in the macro-level relationship between GEO and CPPs is negatively moderated by competitive aggressiveness.

Originality/value

This study offers a first-hand view of negatively moderated-mediation of competitive aggressiveness. Therefore, its findings are extremely relevant for policymakers in the domain of morality, social ethics, corporate-level GEO, sustainability, corporate-level green supply chain learning and CPPs.

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Article
Publication date: 3 May 2013

Zainal Salam, Seh Soon Yee and Yasir Saleem

This paper proposes an improved algorithm to compute selective harmonics elimination pulse width modulation (SHEPWM) angles, based on the Newton‐Raphson (NR) iteration for…

288

Abstract

Purpose

This paper proposes an improved algorithm to compute selective harmonics elimination pulse width modulation (SHEPWM) angles, based on the Newton‐Raphson (NR) iteration for cascaded multilevel inverter (CMI).

Design/methodology/approach

Newton Raphson (NR) is a very popular numerical method for transcendental equations that lack analytical solutions. It has been successfully used to compute the angles for selective harmonics elimination pulse width modulation (SHEPWM) schemes. Despite its effectiveness, NR has not been used for SHEPWM with cascaded multilevel inverter (CMI) structure with equal and non‐equal DC voltage sources. It is known that for CMI, inappropriate selection of initial angles causes long‐iteration time and possibly non‐convergence takes place. The computational difficulty is compounded by the fact that the SHEPWM switching angles need to be correctly sequenced, i.e. each angle must be assigned to the correct output voltage level of the CMI. In this work, an attempt is made to reduce the iteration time and to resolve the non‐convergence problem. The main idea is to relax the switching angle constraint by placing the switching angle sequencing outside the main loop of NR iteration. This allows for the program to run more freely and able to generate more possible solutions for the switching angles. Then these angles are selected to fulfill the requirements of multilevel sequencing. The performance of the proposed technique will be compared with the standard NR for CMI with equal and non‐equal DC sources. The latter case is quite common for CMI with renewable energy applications because the sources normally have different voltage levels.

Findings

Using MATLAB simulation, it will be shown that using this scheme, accurate SHEPWM angles can be achieved for a wide range of fundamental components. Furthermore, significant reduction in iteration time to compute the SHEPWM switching angles is achieved.

Originality/value

This paper proposes an improved algorithm to compute SHEPWM angles based on NR iteration.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 32 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 11 May 2010

Z. Salam

The purpose of this paper is to propose an on‐line algorithm to calculate the switching angles of the harmonics elimination pulse‐width modulation (HEPWM) scheme that can be…

408

Abstract

Purpose

The purpose of this paper is to propose an on‐line algorithm to calculate the switching angles of the harmonics elimination pulse‐width modulation (HEPWM) scheme that can be suitably implemented using a simple microprocessor/microcontroller. It is to be used for three‐phase voltage source inverter (VSI).

Design/methodology/approach

Approximate equations for the HEPWM angles are obtained by performing quadratic curve fittings of the trajectories of the exact HEPWM angles. This paper aims to obtain approximate equation that can be programmed on‐line using microprocessor/microcontroller.

Findings

The main feature of the algorithm is simplicity, whereby only addition and multiplications functions are required. It shall be shown that the proposed scheme allows for an efficient real‐time computation with acceptable error margins. The workability of the algorithm is validated with hardware results.

Practical implications

Since the algorithm allows for on‐line changes of the number of harmonics to be eliminated and an independent control of the fundamental component of the VSI, it is very suitable for motor drive applications.

Originality/value

Owing to the transcendental nature of the HEPWM equations, the exact solution for the switching angles requires vast computing power. The quadratic curve fitting method proposed in this paper simplifies the angle calculations to only multiplication and addition functions. It can be easily implemented using a simple microprocessor/microcontroller.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 29 no. 3
Type: Research Article
ISSN: 0332-1649

Keywords

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Article
Publication date: 13 June 2016

B. Chitti Babu, Suresh Gurjar and Tomas Cermak

This paper aims to present a detailed investigation on the parameter estimation of a photovoltaic (PV) module by using a simplified two-diode model.

188

Abstract

Purpose

This paper aims to present a detailed investigation on the parameter estimation of a photovoltaic (PV) module by using a simplified two-diode model.

Design/methodology/approach

The studied PV module in this paper resembles an ideal two-diode model, and to reduce the computational time, the proposed model has a photocurrent source and two ideal-diodes and neglects the series and shunt resistances. Hence, for calculating the unknown parameters, only four parameters are required from the datasheet. Moreover, the studied model is simple and uses an easy modeling approach which is free from complexities.

Findings

The performance of the PV module is analyzed under non-standard test conditions by considering partial shading at different shaded levels, and it is found that the model has less computational time and gives accurate results.

Originality/value

The usefulness of this PV model is demonstrated with the help of several illustrative figures, and the performance of the PV module is evaluated.

Details

World Journal of Engineering, vol. 13 no. 3
Type: Research Article
ISSN: 1708-5284

Keywords

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Book part
Publication date: 17 July 2024

Laila Albughayl

The challenges that Saudi female leaders face have a major effect on their wellbeing, because their life’s satisfaction as Gärling et al. (2015) pointed out is related to the…

Abstract

The challenges that Saudi female leaders face have a major effect on their wellbeing, because their life’s satisfaction as Gärling et al. (2015) pointed out is related to the balance between mental and physical circumstances that they experience. Additionally, female leaders in Saudi higher education experience considerable job-related stress, and they often lack the strategies and guidance which are necessary to enhance the social and emotional competencies that could help them to cope appropriately with challenges and maintain their wellbeing. Therefore, this chapter presents findings from a qualitative study and unravels Saudi female leaders’ strategies for managing challenges and sustaining their wellbeing in higher education organizations.

Details

The Emerald Handbook of Wellbeing in Higher Education: Global Perspectives on Students, Faculty, Leaders, and Institutions
Type: Book
ISBN: 978-1-83797-505-1

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Article
Publication date: 14 January 2020

Thomas Thangam, Muthuvel K. and Hussein A. Kazem

Increased investment of a photovoltaic (PV) array makes it essential for the client to attain better results from the PV system. The nonlinearity of the PV array and the…

127

Abstract

Purpose

Increased investment of a photovoltaic (PV) array makes it essential for the client to attain better results from the PV system. The nonlinearity of the PV array and the revolution and rotation of the earth require the appliance of maximum power point tracking (MPPT) to the system. Accordingly, grid connected PV systems have turn out to be renowned, because they do not require battery back-ups to accomplish MPPT. Stand-alone systems could also attain MPPT; however, they require appropriate battery back-ups for this function.

Design/methodology/approach

This survey intends to formulate a review on the PV-based microgrid (MG) systems. Here, the literature analyses on diverse techniques associated with PV-based MG systems. It reviews 65 research papers and states the significant analysis. Initially, the analysis depicts various controllers that are contributed in different papers. Subsequently, the analysis also focuses on various features such as PV capacity and inverter topology, and it also analyses the renewable grid source that are exploited in each paper. Furthermore, this paper provides the detailed study regarding the chronological review and performance achievements in each contribution. Finally, it extends the various research issues which can be useful for the researchers to accomplish further research on PV-based MG systems.

Findings

This paper has presented a detailed review on PV-based MG systems that were enumerated in the above sections. Here, various controllers along with their better achievements were analyzed and described. From the review, it was known that several PV-based MG systems were really at the point for enabling better power output and conversion efficiency. In conclusion, this paper reviewed about 65 research papers and declared the significant analysis. Initially, the analysis also focused on various controller classifications in PV-based MG systems that were reviewed in this paper. Subsequently, the analysis also focused on various features, such as PV capacity and inverter topology. The analysis also reviewed the performance achievements and renewable gird source that were exploited in PV-based MG systems. At last, this paper has presented various research issues which can be useful for the researchers to accomplish further research on the features of PV-based MG systems.

Originality/value

This paper presents a brief analysis of PV-based MG systems. This is the first work that uses PV-based MG systems for better regulation of MPPT.

Details

World Journal of Engineering, vol. 17 no. 2
Type: Research Article
ISSN: 1708-5284

Keywords

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