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1 – 5 of 5Zakaria Mohamed Salem Elbarbary, Ahmed A. Alaifi, Saad Fahed Alqahtani, Irshad Mohammad Shaik, Sunil Kumar Gupta and Vijayakumar Gali
Switching power converters for photovoltaic (PV) applications with high gain are rapidly expanding. To obtain better voltage gain, low switch stress, low ripple and cost-effective…
Abstract
Purpose
Switching power converters for photovoltaic (PV) applications with high gain are rapidly expanding. To obtain better voltage gain, low switch stress, low ripple and cost-effective converters, researchers are developing several topologies.
Design/methodology/approach
It was decided to use the particle swarm optimization approach for this system in order to compute the precise PI controller gain parameters under steady state and dynamic changing circumstances. A high-gain q- ZS boost converter is used as an intermittent converter between a PV and brushless direct current (BLDC) motor to attain maximum power point tracking, which also reduces the torque ripples. A MATLAB/Simulink environment has been used to build and test the positive output quadratic boost high gain converters (PQBHGC)-1, PQBHGC-8, PQBHGC-4 and PQBHGC-3 topologies to analyse their effectiveness in PV-driven BLDC motor applications. The simulation results show that the PQBHGC-3 topology is effective in comparison with other HG cell DC–DC converters in terms of efficiency, reduced ripples, etc. which is most suitable for PV-driven BLDC applications.
Findings
The simulation results have showed that the PQBHGC-3 gives better performance with minimum voltage ripple of 2V and current ripple of 0.4A which eventually reduces the ripples in the torque in a BLDC motor. Also, the efficiency for the suggested PQBHGC-3 for PV-based BLDC applications is the best with 99%.
Originality/value
This study is the first of its kind comparing the different topologies of PQBHGC-1, PQBHGC-8, PQBHGC-4 and PQBHGC-3 topologies to analyse their effectiveness in PV-driven BLDC motor applications. This study suggests that the PQBHGC-3 topology is most suitable in PV-driven BLDC applications.
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Bas Becker and Carel Roessingh
Multisited ethnography has primarily been portrayed as a challenge for the following field-worker, with the researcher taking the central role and neglecting research participants…
Abstract
Purpose
Multisited ethnography has primarily been portrayed as a challenge for the following field-worker, with the researcher taking the central role and neglecting research participants also experiencing a multisited nature of their work. The authors argue that literature on multisited ethnography merely discusses multisitedness as a methodological theme. In correspondence, the authors propose to think of multisitedness not just as a methodological theme but also as an empirical theme.
Design/methodology/approach
The authors contend etic and emic perspectives to address multisitedness empirically, which enables researchers to compare and contrast the multisited topic of inquiry in academic “outsider” terms with the etic analysis and considering the perspective of the research participants' multisited experiences using the emic perspective. To show the fruitfulness of discussing multisitedness using the complementary etic and emic analysis, the authors present the example of Mennonite entrepreneurial activities in Belize, a heterogeneous group of migrants that established themselves as successful traders and entrepreneurs.
Findings
Through an etic multisited ethnographic perspective, the authors compare and contrast four communities of Mennonites in terms of their entrepreneurial activities, technology and energy use. Through an emic perspective, the authors demonstrate how Mennonites, while preferring an in-group focus, navigate their multisited entrepreneurial activities, which require interaction with the outside world.
Originality/value
The authors highlight the value of combining etic–emic reflections to acknowledge and include the multisited nature of many social phenomena as experienced by the research participants.
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Adella Grace Migisha, Joseph Mapeera Ntayi, Muyiwa S. Adaramola, Faisal Buyinza, Livingstone Senyonga and Joyce Abaliwano
An unreliable supply of grid electricity has a strong negative impact on industrial and commercial profitability as well as on household activities and government services that…
Abstract
Purpose
An unreliable supply of grid electricity has a strong negative impact on industrial and commercial profitability as well as on household activities and government services that rely on electricity supply. This unreliable grid electricity could be a result of technical and security factors affecting the grid network. Therefore, this study aims to investigate the effects of technical and security factors on the transmission and distribution of grid electricity in Uganda.
Design/methodology/approach
This study used the ordinary least squares (OLS) and autoregressive distributed lag (ARDL) models to examine the effects of technical and security factors on grid electricity reliability in Uganda. The study draws upon secondary time series monthly data sourced from the Uganda Electricity Transmission Company Limited (UETCL) government utility, which transmits electricity to both distributors and grid users. Additionally, data from Umeme Limited, the largest power distribution utility in Uganda, were incorporated into the analysis.
Findings
The findings revealed that technical faults, failed grid equipment, system overload and theft and vandalism affected grid electricity reliability in the transmission and distribution subsystems of the Ugandan power grid network. The effect was computed both in terms of frequency and duration of power outages. For instance, the number of power outages was 116 and 2,307 for transmission and distribution subsystems, respectively. In terms of duration, the power outages reported on average were 1,248 h and 5,826 h, respectively, for transmission and distribution subsystems.
Originality/value
This paper investigates the effects of technical and security factors on the transmission and distribution grid electricity reliability, specifically focusing on frequency and duration of power outages, in the Ugandan context. It combines both OLS and ARDL models for analysis and adopts the systems reliability theory in the area of grid electricity reliability research.
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Debora Gottardello and Solmaz Filiz Karabag
Using the lens of crisis innovation and strategic alignment, this study explores how a segment of the restaurant sector that may be less agile than others—Michelin-starred…
Abstract
Purpose
Using the lens of crisis innovation and strategic alignment, this study explores how a segment of the restaurant sector that may be less agile than others—Michelin-starred restaurants—perceives and aligns with the challenges brought about by the COVID-19-pandemic.
Design/methodology/approach
The study collected data from 19 Michelin-starred restaurants in Spain using a qualitative interview method. The data were analyzed qualitatively and organized thematically.
Findings
Four key categories of strategic challenges were identified: human resources, uncertainty, control and economic challenges. In response, chefs displayed both behavioral and organizational strategies. Those organizational strategies were new human resource management, reorganization, product and service innovation and marketing. While the new human resource management actions adopted to align with the human resource challenges identified, a misalignment remains between some of the other strategic actions, such as product and service innovation, marketing and economic and uncertainty challenges.
Originality/value
The findings offer new insight into Michelin-starred restaurant chefs' challenges and (mis)alignment strategies, an area that has been understudied in the current literature on innovative responses in the hospitality sector post-pandemic.
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Erik Melin and Johan Gaddefors
The purpose of this article is to explore how agency is distributed between human actors and nonhuman elements in entrepreneurship.
Abstract
Purpose
The purpose of this article is to explore how agency is distributed between human actors and nonhuman elements in entrepreneurship.
Design/methodology/approach
It is based on an inductive longitudinal case study of a garden in a rural community in northern Sweden. The methodology includes an ethnography of the garden, spanning the course of 16 years, and a careful investigation of the entrepreneurial processes contained within it.
Findings
This article identifies and describes different practices to explain how agency is distributed between human actors and nonhuman elements in the garden's context. Three different practices were identified and discussed, namely “calling”, “resisting”, and “provoking”.
Originality/value
Agency/structure constitutes a longstanding conundrum in entrepreneurship and context. This study contributes to the on-going debate on context in entrepreneurship, and introduces a posthumanist perspective—particularly that of distributed agency—to theorising in entrepreneurship. Rather than focussing on a human (hero)-driven change process, induced through the exploitation of material objects, this novel perspective views entrepreneurship as both a human and a nonhuman venture, occurring through interactions located in particular places and times. Coming from the agency/structure dichotomy, this article reaches out for elements traditionally established on the structure side, distributing them to the agency side of the dichotomy. As such, it contributes to an understanding of the agency of nonhuman elements, and how they direct entrepreneurship in context. This theoretical development prepares entrepreneurship theories to be better able to engage with nonhuman elements and provides example solutions for the ongoing climate crisis.
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