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Article
Publication date: 27 February 2024

Karthikeyan Paramanandam, Venkatachalapathy S, Balamurugan Srinivasan and Nanda Kishore P V R

This study aims to minimize the pressure drop across wavy microchannels using secondary branches without compromising its capacity to transfer the heat. The impact of secondary…

147

Abstract

Purpose

This study aims to minimize the pressure drop across wavy microchannels using secondary branches without compromising its capacity to transfer the heat. The impact of secondary flows on the pressure drop and heat transfer capabilities at different Reynolds numbers are investigated numerically for different wavy microchannels. Finally, different channels are evaluated using performance evaluation criteria to determine their effectiveness.

Design/methodology/approach

To investigate the flow and heat transfer capabilities in wavy microchannels having secondary branches, a 3D conjugate heat transfer model based on finite volume method is used. In conventional wavy microchannel, secondary branches are introduced at crest and trough locations. For the numerical simulation, a single symmetrical channel is used to minimize computational time and resources and the flow within the channels remains single-phase and laminar.

Findings

The findings indicate that the suggested secondary channels notably improve heat transfer and decrease pressure drop within the channels. At lower flow rates, the secondary channels demonstrate superior performance in terms of heat transfer. However, the performance declines as the flow rate increased. With the same amplitude and wavelength, the introduction of secondary channels reduces the pressure drop compared with conventional wavy channels. Due to the presence of secondary channels, the flow splits from the main channel, and part of the core flow gets diverted into the secondary channel as the flow takes the path of minimum resistance. Due to this flow split, the core velocity is reduced. An increase in flow area helps in reducing pressure drop.

Practical implications

Many complex and intricate microchannels are proposed by the researchers to augment heat dissipation. There are challenges in the fabrication of microchannels, such as surface finish and achieving the required dimensions. However, due to the recent developments in metal additive manufacturing and microfabrication techniques, the complex shapes proposed in this paper are feasible to fabricate.

Originality/value

Wavy channels are widely used in heat transfer and micro-fluidics applications. The proposed wavy microchannels with secondary channels are different when compared to conventional wavy channels and can be used practically to solve thermal challenges. They help achieve a lower pressure drop in wavy microchannels without compromising heat transfer performance.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 34 no. 4
Type: Research Article
ISSN: 0961-5539

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Abstract

Details

Change Management for Organizations
Type: Book
ISBN: 978-1-78714-119-3

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Article
Publication date: 15 August 2023

Shriyuta Abhishek and Nanda Kishore Kannuri

Migrants face some unique health-care challenges, which often remain unaddressed by the health system. The purpose of this study is to determine health-care access among migrants…

91

Abstract

Purpose

Migrants face some unique health-care challenges, which often remain unaddressed by the health system. The purpose of this study is to determine health-care access among migrants in Chhattisgarh, from a lens of health equity.

Design/methodology/approach

This study was conducted in a government-built tenement under the Integrated Housing and Slum Development program in Bilaspur district of Chhattisgarh state of India. It is a mixed-methods study which used a survey method, focus group discussion, in depth-interviews, semi-structured interviews and non-participant observations of health facilities in the area. Respondents included residents (migrants) and other local stakeholders like the Chief Medical Officer of the district, elected representatives of the local government and frontline health workers. This paper focuses on the findings from the qualitative component of the study.

Findings

The move to resettle the people living in the slums to the periphery of the city had a negative impact on their health-care access. They find it difficult to access public health services, given the services are concentrated in the city. Women, elderly people and disabled people grapple with additional challenges in being able to access basic reproductive health services and care for chronic illnesses. Equity in health-care access is linked to various social determinants of health including access to housing and social security. However, the authors found that the migrant community is being deprived of appropriate housing facilities and social security.

Originality/value

This paper explores the health-care access of internal migrants in Chhattisgarh state of India in the larger context of urban development with a focus on health equity.

Details

International Journal of Migration, Health and Social Care, vol. 19 no. 3/4
Type: Research Article
ISSN: 1747-9894

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Article
Publication date: 2 January 2018

Mahmoud M. Elkholy

The paper aims to present an application of teaching learning-based optimization (TLBO) algorithm and static Var compensator (SVC) to improve the steady state and dynamic…

134

Abstract

Purpose

The paper aims to present an application of teaching learning-based optimization (TLBO) algorithm and static Var compensator (SVC) to improve the steady state and dynamic performance of self-excited induction generators (SEIG).

Design/methodology/approach

The TLBO algorithm is applied to generate the optimal capacitance to maintain rated voltage with different types of prime mover. For a constant speed prime mover, the TLBO algorithm attains the optimal capacitance to have rated load voltage at different loading conditions. In the case of variable speed prime mover, the TLBO methodology is used to obtain the optimal capacitance and prime mover speed to have rated load voltage and frequency. The SVC of fixed capacitor and controlled reactor is used to have a fine tune in capacitance value and control the reactive power. The parameters of SVC are obtained using the TLBO algorithm.

Findings

The whole system of three-phase induction generator and SVC are established under MatLab/Simulink environment. The performance of the SEIG is demonstrated on two different ratings (i.e. 7.5 kW and 1.5 kW) using the TLBO algorithm and SVC. An experimental setup is built-up using a 1.5 kW three-phase induction machine to confirm the theoretical analysis. The TLBO results are matched with other meta heuristic optimization techniques.

Originality/value

The paper presents an application of the meta-heuristic algorithms and SVC to analysis the steady state and dynamic performance of SEIG with optimal performance.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 37 no. 1
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 12 November 2018

Michael White and Dimitrios Papastamos

This paper aims to examine the housing market in Greece after the Global Financial Crisis focussing on regional analysis and urban markets in Athens and Thessaloniki.

278

Abstract

Purpose

This paper aims to examine the housing market in Greece after the Global Financial Crisis focussing on regional analysis and urban markets in Athens and Thessaloniki.

Design/methodology/approach

The paper uses a data set of over 70,750 property values from 2007 until 2014 incorporating characteristics variables upon which hedonic models are estimated. These form the bases for calculating value indices for mix adjusted houses/apartments by year and region. The indices are used in a panel model in which regional and economic variables are included as independent variables. Using advances in dynamic panel data modelling, a bias-corrected least squares dummy variable corrected (LSDVC) model is applied.

Findings

Results indicate the importance of macroeconomic variables in terms of the role of disposable income and significantly different regional effects. Examining the major urban markets, results indicate significant differences in the response of house values to exogenous demand side influences, consistent with the finding of significant regional differences in the LSDVC.

Research limitations/implications

While data on valuations are used that may contain smoothing, the data set covers a large sample of residential properties. As regional economic differences are significant and persistent, housing markets will also behave differently, and hence national policies, unless targeted, will have regionally differentiated effects.

Practical implications

Regional heterogeneity needs to be considered in model estimation.

Social implications

Policymakers should consider regional differences to improve policy effectiveness.

Originality/value

This is the first paper to use a large sample of residential properties in Greece and apply the LSDVC model to overcome estimation biases.

Details

Journal of European Real Estate Research, vol. 11 no. 3
Type: Research Article
ISSN: 1753-9269

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Article
Publication date: 14 September 2010

Khurshid Hafiz, Gaurav Nanda and Narayan C. Kar

In order to assess the performance of an induction generator in standalone wind power application, it is imperative that mathematical models are developed that accurately…

915

Abstract

Purpose

In order to assess the performance of an induction generator in standalone wind power application, it is imperative that mathematical models are developed that accurately represent the system and take into account various electromagnetic influences such as skin effect. The purpose of this paper is to utilize mathematical models to study the transient and steady‐state behaviour of the self‐excited induction generator (SEIG), in one case with an aluminum rotor, in another case, with a copper rotor, under various load conditions while taking the above factor into account.

Design/methodology/approach

Mathematical models of a SEIG in the d‐q axis frame have been developed based on the generalized machine theory. A relationship between the mutual inductance and the magnetizing current of the machine has been presented. The rotor impedances have been customized to include skin effect. Using these relations, the model has been extended to include the saturation and skin effects. In order to verify the accuracy of the models, numerical and experimental investigations have been carried out on two 7.5 hp aluminum‐rotor and copper‐rotor SEIGs.

Findings

It was found that the model that takes into account the saturation and skin effects produces numerical results that closely match experimental values for both the machines.

Originality/value

This paper describes how a model of an SEIG considering saturation and skin effect has been developed and applied to aluminum‐ and copper‐rotor machines of similar power ratings to analyze their performance.

Details

COMPEL - The international journal for computation and mathematics in electrical and electronic engineering, vol. 29 no. 5
Type: Research Article
ISSN: 0332-1649

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Article
Publication date: 31 January 2022

Akash Gupta and Manjeet Singh

The purpose of this study is to check the reliability of a multi-pin joint to be a fail-safe joint by considering different geometric and material parameters. The pin joints are…

63

Abstract

Purpose

The purpose of this study is to check the reliability of a multi-pin joint to be a fail-safe joint by considering different geometric and material parameters. The pin joints are made of uni-directional fiberglass that has been impregnated with epoxy composites incorporating 3% nano-clay.

Design/methodology/approach

This study incorporates the analysis of multi-pin joints experimentally, numerically and statistically using the Weibull approach. During analyses, geometrical parameters edge to diameter (E:D), longitudinal pitch to diameter (F:D), side edge to diameter (S:D) and transverse pitch to diameter (P:D) were analyzed using the Taguchi method with a higher-the-better L16 orthogonal array.

Findings

This study aims to develop multi-pin laminated joints to attain higher reliability, which have been designated as fail-safe joints for the intended application and which have higher joint strength. The study reveals that to achieve 99% reliability or 1% probability of failure using the Weibull approach, 24.4% load decrement from the experimental result recorded for three-pin joint configuration at E:D = 4, F:D = 5, S:D = 4 and P:D = 5. Similarly, for the four-pin configuration at E:D = 4, F:D = 4, S:D = 4 and P:D = 5, 23.07% of load decrement observed from the experimental result implies that the expected load with a 99% reliability offers a safe load.

Originality/value

A reliability analysis on multi-pin joints was not conducted in structural application. Composite materials are used because of high reliability and high strength-to-weight ratio. So, in the present work, reliability of the multi-pin joint is analyzed using Weibull distribution.

Details

World Journal of Engineering, vol. 20 no. 4
Type: Research Article
ISSN: 1708-5284

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Article
Publication date: 22 August 2023

Umar Saba Dangana and Namnso Bassey Udoekanem

The rising concern for the accuracy of residential valuations in Nigeria has created the need for key stakeholders in the residential property markets in the study areas to know…

132

Abstract

Purpose

The rising concern for the accuracy of residential valuations in Nigeria has created the need for key stakeholders in the residential property markets in the study areas to know the level of accuracy of valuations in order to make rational residential property transactions, amongst other purposes.

Design/methodology/approach

A blend of descriptive and causal designs was adopted for the study. Data were collected via structured questionnaire administered to 179 estate surveying and valuation (ESV) firms in the study areas using census sampling technique. Analytical techniques such as median percentage error (PE), mean and relative importance index (RII) analysis were employed in the analysis of data collected for the study.

Findings

The study found that valuation accuracy is greater in the residential property market in Abuja than in Minna, with inappropriate valuation methodology as the most significant cause of valuation inaccuracy.

Practical implications

The practical implication of this study is that a reliable databank should be established for the property market to provide credible transaction data for valuers to conduct accurate valuations in these cities. Strict enforcement of national and international valuation standards by the regulatory authorities as well as retraining of valuers on appropriate application of valuation approaches and methods are the recommended corrective measures.

Originality/value

No study has comparatively examined the accuracy of valuations in two extremely different residential property markets in the country using actual valuation and transaction prices.

Details

Property Management, vol. 42 no. 2
Type: Research Article
ISSN: 0263-7472

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Article
Publication date: 18 October 2021

Dulani Jayasuriya Daluwathumullagamage

The business model of monoline insurers is to guarantee payments of debt issues in case of defaults by the issuer. Although sparse attention is given to monolines in literature…

215

Abstract

Purpose

The business model of monoline insurers is to guarantee payments of debt issues in case of defaults by the issuer. Although sparse attention is given to monolines in literature, they play an important role in enabling municipalities and firms in refinancing. This study aims to conduct a systematic review of 181 articles from 1990 to 2020 from 23,130 records and a case study on the key monoline insurers. Key failure, success factors and demand for future monoline insurance are identified. Finally, the study explores monolines’ potential during COVID-19 and develops a framework for monoline governance and regulation.

Design/methodology/approach

The study follows Briner and Denyer and Moher et al. to implement the systematic review. The methodology involves ascertaining the motivation behind the review, and formulating research questions; aggregating relevant prior literature from scientific databases, conducting quality assessment and synthesising the data; and conducting extensive analysis for framework development. Case study methodology foundation phase focuses on understanding the research philosophy. The second phase involves documenting the procedures involved. The final phase involves collecting the relevant quantitative and qualitative material. In addition, collecting empirical data from numerous sources allows triangulation.

Findings

The review results of 181 articles from 1990 to 2020 show that peak article counts occur in 2010 and 2013 (nine academic studies) and in 2008 and 2010 (six industry studies). Over- and under-explored domains happen to be bond pricing (86 academic studies) and bond markets (36 industry studies) and corporate bonds (19 academic studies), respectively. The study highlights failure factors such as adverse selection, premiums mispricings, inadequate capital and regulation, untimely downgrades and governance issues; and identifies success factors such as conservative underwriting, early financing, competitor business acquisitions and obtaining put-back claims. Potential during COVID-19 is discussed and a monoline governance framework is developed.

Research limitations/implications

Search and selection criteria distortions may lead to sample selection bias in systematic reviews. Issue is addressed by using different permutations of the search key words to refine the search criteria. Reference list of collected final sample of articles are perused to identify additional articles. It is difficult to obtain verifiable empirical data on the bond/monoline insurers or their insured products, especially for the structured finance sector. Most of the information available on data stream and firm’s quarterly financial reports for publicly traded monoline/bond insurers and credit rating reports are included to overcome this issue.

Practical implications

Demand for bond/monoline insurance still persists even in the USA. Although borrowing costs are low, obtaining bank loans would be challenging for municipalities and corporates with increased risks. Especially, given worldwide government stimulus on wages, most municipalities would possess reduced budgets for public finance. Monoline insurance can play a key role in financing such projects. Thus, it is important to understand their unique traditional and transformed business model and applicability during and post-COVID-19. Given the near extinction of bond/monoline insurers during the 2008 global financial crisis (GFC), an adequate framework for bond/monoline insurers as developed in this study is key for future business continuity.

Social implications

There is significant interest, especially, from the industry on monolines as identified in our systematic review. Monoline insurance has major effects on taxpayers, government policies and bond investors. They aid in financing public finance projects that have significant societal impact. This study contributes by filling existing gaps in the literature, especially, from a behavioural, ethical and social perspective of the monolines, regulators, other stakeholders and new entrants to the industry during COVID-19. This study links prior finance theories to the impact of bond/monoline insurer’s during the 2008 GFC and their stakeholders involved that has societal implications.

Originality/value

This study can be differentiated from prior research on monoline insurers as follows: The study identifies, gaps, similarities, trends between prior academic and industry literature and develop a bond/monoline governance framework; identifies key failure and success factors during the 2008 GFC crisis to develop the governance framework and identify monolines’ potential during COVID-19; as opposed to most prior literature that only focus on one (Drake and Neal, 2011 analyse MBIA) or two key bond/monoline insurers, this study focuses on five key bond/monoline insurers in detail and all other key insurers as well in the empirical analysis section.

Details

Qualitative Research in Financial Markets, vol. 14 no. 1
Type: Research Article
ISSN: 1755-4179

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Article
Publication date: 17 October 2023

Sarikha Srinivasavarathan and Poornima Rajendran

The international academic literature agrees that principals act as change agents and are vital in creating and promoting an inclusive school culture. In this article, the authors…

117

Abstract

Purpose

The international academic literature agrees that principals act as change agents and are vital in creating and promoting an inclusive school culture. In this article, the authors proclaim that Indian schools lack school leadership to accomplish inclusive education (IE) characterized by local needs. The article emphasizes the importance of school principals and discusses how principal vacancies, insufficient training and lack of autonomy jeopardize inclusive and equitable quality education in Indian schools. Contextualized policies, professional standards for principals, research that highlights principals' perspectives and autonomy for principals are required to strengthen principals, who are the primary advocates for IE, to create a more democratic, equitable and just society.

Design/methodology/approach

The authors base their arguments and opinions on the latest National Education Policy (NEP, 2020), data/statistics from various educational organizations in India, and research findings of global scholars.

Findings

The data and statistics show that principals in Indian schools do not receive the essential assistance to implement IE successfully. A lack of adequate data regarding the subject of debate is another point made by the authors.

Social implications

Understanding the hardships faced by Indian school principals would help readers recognize the leadership challenges for IE in India. Addressing these challenges is one of the best ways to fulfill the equity and inclusion goals emphasized in UN Sustainable Development Goal #4.

Originality/value

This article is the first to emphasize the importance of prioritizing principals in Indian schools, among other agents when trying to achieve inclusion.

Details

Asian Education and Development Studies, vol. 12 no. 4/5
Type: Research Article
ISSN: 2046-3162

Keywords

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