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Article
Publication date: 23 June 2023

Sílvio Aparecido Verdério Júnior, Pedro J. Coelho, Vicente Luiz Scalon and Santiago del Rio Oliveira

The purpose of this study is to numerically and experimentally investigate the natural convection heat transfer in flat plates and plates with square, trapezoidal and triangular…

105

Abstract

Purpose

The purpose of this study is to numerically and experimentally investigate the natural convection heat transfer in flat plates and plates with square, trapezoidal and triangular corrugations.

Design/methodology/approach

This work is an extension of the previous studies by Verderio et al. (2021a, 2021b, 2021c, 2021d, 2022a). An experimental apparatus was built to measure the plates’ temperatures during the natural convection cooling process. Several physical parameters were evaluated through the experimental methodology. Free and open-source computational tools were used to simulate the experimental conditions and to quantitatively and qualitatively evaluate the thermal plume characteristics over the plates.

Findings

The numerical results were experimentally validated with reasonable accuracy in the range of studied RaLP for the different plates. Empirical correlations of Nu¯LPexp=f(RaLP), h¯conv=f(RaLP) and Nu¯LPexp(A/AP)=f(RaLP), with good accuracy and statistical representativeness, were obtained for the studied geometries. The convective thermal efficiency of corrugated plates (Δη), as a function of RaLP, was also experimentally studied quantitatively. In agreement with the findings of Oosthuizen and Garrett (2001), the experimental and numerical results proved that the increase in the heat exchange area of the corrugations has a greater influence on the convective exchange and the thermal efficiency than the disturbances caused in the flow (which reduce h¯conv). The plate with trapezoidal corrugations presented the highest convective thermal efficiency, followed by the plates with square and triangular corrugations. It was also proved that the thermal efficiency of corrugated plates increases with RaLP.

Practical implications

The results demonstrate that corrugated surfaces have greater thermal efficiency than flat plates in heating and/or cooling systems by natural convection. This way, corrugated plates can reduce the dependence on auxiliary forced convection systems, with application in technological areas and Industry 4.0.

Originality/value

The empirical correlations obtained for the corrected Nusselt number and thermal efficiency for the corrugated plate geometries studied are original and unpublished, as well as the experimental validation of the developed three-dimensional numerical code.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 33 no. 9
Type: Research Article
ISSN: 0961-5539

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Article
Publication date: 28 February 2024

Sílvio Aparecido Verdério Júnior, Pedro J. Coelho and Vicente Luiz Scalon

The purpose of this study is to numerically investigate the geometric influence of different corrugation profiles (rectangular, trapezoidal and triangular) of varying heights on…

151

Abstract

Purpose

The purpose of this study is to numerically investigate the geometric influence of different corrugation profiles (rectangular, trapezoidal and triangular) of varying heights on the flow and the natural convection heat transfer process over isothermal plates.

Design/methodology/approach

This work is an extension and finalization of previous studies of the leading author. The numerical methodology was proposed and experimentally validated in previous studies. Using OpenFOAM® and other free and open-source numerical-computational tools, three-dimensional numerical models were built to simulate the flow and the natural convection heat transfer process over isothermal corrugation plates with variable and constant heights.

Findings

The influence of different geometric arrangements of corrugated plates on the flow and natural convection heat transfer over isothermal plates is investigated. The influence of the height ratio parameter, as well as the resulting concave and convex profiles, on the parameters average Nusselt number, corrected average Nusselt number and convective thermal efficiency gain, is analyzed. It is shown that the total convective heat transfer and the convective thermal efficiency gain increase with the increase of the height ratio. The numerical results confirm previous findings about the predominant effects on the predominant impact of increasing the heat transfer area on the thermal efficiency gain in corrugated surfaces, in contrast to the adverse effects caused on the flow. In corrugations with heights resulting in concave profiles, the geometry with triangular corrugations presented the highest total convection heat transfer, followed by trapezoidal and rectangular. For arrangements with the same area, it was demonstrated that corrugations of constant and variable height are approximately equivalent in terms of natural convection heat transfer.

Practical implications

The results allowed a better understanding of the flow characteristics and the natural convection heat transfer process over isothermal plates with corrugations of variable height. The advantages of the surfaces studied in terms of increasing convective thermal efficiency were demonstrated, with the potential to be used in cooling systems exclusively by natural convection (or with reduced dependence on forced convection cooling systems), including in technological applications of microelectronics, robotics, internet of things (IoT), artificial intelligence, information technology, industry 4.0, etc.

Originality/value

To the best of the authors’ knowledge, the results presented are new in the scientific literature. Unlike previous studies conducted by the leading author, this analysis specifically analyzed the natural convection phenomenon over plates with variable-height corrugations. The obtained results will contribute to projects to improve and optimize natural convection cooling systems.

Details

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

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Article
Publication date: 8 May 2017

Pedro Gaudencio, Arnaldo Coelho and Neuza Ribeiro

The purpose of this paper is to show how organizational corporate social responsibility (CSR) can influence workers’ attitudes and behaviors, especially in terms of affective…

1582

Abstract

Purpose

The purpose of this paper is to show how organizational corporate social responsibility (CSR) can influence workers’ attitudes and behaviors, especially in terms of affective commitment (AC), job satisfaction (JS), and turnover intention (TI). A second aim is to explore the social exchange process that may underlie this relationship, by examining the mediating role of organizational trust (OT).

Design/methodology/approach

The authors employ structural equation modeling based on survey data obtained from 315 Portuguese individuals.

Findings

The findings show that perceptions of CSR predict workers’ attitudes and behaviors directly through the mediating role of OT. They suggest that managers should implement CSR practices because these can contribute toward fostering OT, improving workers’ AC and JS, and reducing TI.

Originality/value

This study enriches the existing knowledge about social exchange relationships in organizational contexts, and responds to the need to understand underlying mechanisms linking CSR with workers’ organizational outcomes, by analyzing CSR practices in a holistic stakeholder perspective.

Details

Journal of Management Development, vol. 36 no. 4
Type: Research Article
ISSN: 0262-1711

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Article
Publication date: 19 March 2019

Ana Claudia Braun Endo, Luiz Alberto de Farias and Pedro Simões Coelho

The purpose of this paper is to provide empirical insights about service branding from higher education administrators (HEAs) perspectives and to identify the main factors…

803

Abstract

Purpose

The purpose of this paper is to provide empirical insights about service branding from higher education administrators (HEAs) perspectives and to identify the main factors involved in their strategic thinking in this sector.

Design/methodology/approach

Adopting a qualitative approach, 22 in-depth interviews were performed in Brazilian HEAs to analyze service branding as a strategic institutional process in this context.

Findings

Findings reveal that service branding depends on several factors, e.g., in this case, deep integration between branding and services, leadership involvement, strong value propositions, sharing of strategic guidelines, branding experiences and, finally, credibility and reputation. Excellence of service is considered essential in higher education (HE) and, therefore, service branding faces the challenge of promoting the provision of quality services.

Originality/value

Although there have been many studies relating to HE and branding, few authors have studied service branding in educational sector and which issues must be observed in a competitive marketplace.

Details

Marketing Intelligence & Planning, vol. 37 no. 4
Type: Research Article
ISSN: 0263-4503

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Article
Publication date: 1 March 1990

Maria da Graça Carvalho and Pedro Jorge Coelho

A fully three‐dimensional model has been applied to an oil‐fired water tube boiler in order to predict the flow, temperature, mixture fraction, species concentrations and the heat…

73

Abstract

A fully three‐dimensional model has been applied to an oil‐fired water tube boiler in order to predict the flow, temperature, mixture fraction, species concentrations and the heat flux distributions to the furnace walls. The partial differential equations governing conservation of mass, momentum and energy as well as those describing the combustion phenomena are discretized by a finite volume method and solved numerically. Radiative heat transfer is handled by the discrete transfer method. Predicted results are presented and compared with experimental data for the heat fluxes. The results have suggested that 3‐D models of the present kind can be used with some confidence for design calculations.

Details

Engineering Computations, vol. 7 no. 3
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 17 October 2016

Georg Fassott, Jörg Henseler and Pedro S. Coelho

The purpose of this paper is to explain how to model moderating effects of composites using partial least squares (PLS) path modeling. It provides the methodological underpinning…

4411

Abstract

Purpose

The purpose of this paper is to explain how to model moderating effects of composites using partial least squares (PLS) path modeling. It provides the methodological underpinning of moderating effects in general and describes the various approaches for forming the interaction term, i.e., the product indicator approach, the two-stage approach, and orthogonalization.

Design/methodology/approach

The paper discusses the use of standardized vs unstandardized construct scores and introduces spotlight analysis as a useful way to report findings.

Findings

Researchers should rely on unstandardized estimates when analyzing moderating effects. Centering or orthogonalization can help improve the interpretability of path coefficients.

Practical implications

PLS software implementations should facilitate unstandardized estimates.

Originality/value

This paper formulates step by step guidelines for analyzing moderating effects of composites using PLS path modeling. It is the first to propose spotlight analysis for PLS path modeling.

Details

Industrial Management & Data Systems, vol. 116 no. 9
Type: Research Article
ISSN: 0263-5577

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Article
Publication date: 9 January 2017

Rita Coelho do Vale and Pedro Verga Matos

The purpose of this paper is to understand the importance of private labels (PLs) offered by each retailer on store loyalty, combining different loyalty-driven factors and…

1323

Abstract

Purpose

The purpose of this paper is to understand the importance of private labels (PLs) offered by each retailer on store loyalty, combining different loyalty-driven factors and assessing the importance of PLs on different loyalty stages – attitudinal and behavioural store loyalty.

Design/methodology/approach

Data were collected through a questionnaire (online survey) run in Portugal (n=469). Multi-level regressions were run to estimate the different loyalty models (base and full models) on each loyalty stage.

Findings

Results stress the positive contribution of PLs on consumers’ loyalty across different loyalty stages. However, findings suggest that this relationship may not be as strong as suggested in earlier studies. Findings highlight the importance of distinguishing between attitudinal and behavioural loyalty, emphasizing the complexity of the consumer loyalty construct and that multiple store-related factors can positively contribute to it.

Research limitations/implications

Data were collected in one single country. It would be interesting to collect similar data in other countries in order to assess the extent to which results prevail across different competitive and cultural contexts.

Practical implications

Findings indicate that the loyalty factors that contribute to store loyalty are not homogeneous across the different loyalty stages, strengthening the idea that retailers should adopt different loyalty strategies depending on the loyalty stage its target customers are in.

Originality/value

This study is the first of its kind combining in a single framework the loyalty towards the retailers’ brand, store-related variables (in-store and economic factors), and specific consumer and retailer characteristics across different loyalty stages.

Details

International Journal of Retail & Distribution Management, vol. 45 no. 1
Type: Research Article
ISSN: 0959-0552

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Article
Publication date: 26 July 2024

Guilherme Fonseca Gonçalves, Rui Pedro Cardoso Coelho and Igor André Rodrigues Lopes

The purpose of this research is to establish a robust numerical framework for the calibration of macroscopic constitutive parameters, based on the analysis of polycrystalline RVEs…

87

Abstract

Purpose

The purpose of this research is to establish a robust numerical framework for the calibration of macroscopic constitutive parameters, based on the analysis of polycrystalline RVEs with computational homogenisation.

Design/methodology/approach

This framework is composed of four building-blocks: (1) the multi-scale model, consisting of polycrystalline RVEs, where the grains are modelled with anisotropic crystal plasticity, and computational homogenisation to link the scales, (2) a set of loading cases to generate the reference responses, (3) the von Mises elasto-plastic model to be calibrated, and (4) the optimisation algorithms to solve the inverse identification problem. Several optimisation algorithms are assessed through a reference identification problem. Thereafter, different calibration strategies are tested. The accuracy of the calibrated models is evaluated by comparing their results against an FE2 model and experimental data.

Findings

In the initial tests, the LIPO optimiser performs the best. Good results accuracy is obtained with the calibrated constitutive models. The computing time needed by the FE2 simulations is 5 orders of magnitude larger, compared to the standard macroscopic simulations, demonstrating how this framework is suitable to obtain efficient micro-mechanics-informed constitutive models.

Originality/value

This contribution proposes a numerical framework, based on FE2 and macro-scale single element simulations, where the calibration of constitutive laws is informed by multi-scale analysis. The most efficient combination of optimisation algorithm and definition of the objective function is studied, and the robustness of the proposed approach is demonstrated by validation with both numerical and experimental data.

Details

Engineering Computations, vol. ahead-of-print no. ahead-of-print
Type: Research Article
ISSN: 0264-4401

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Article
Publication date: 16 August 2024

Everton Coelho, Mário Augusto and Pedro Torres

This study aims to clarify the influence of different CEO’s political orientation (liberal/conservative) and corporate political activity on ESG performance, considering…

315

Abstract

Purpose

This study aims to clarify the influence of different CEO’s political orientation (liberal/conservative) and corporate political activity on ESG performance, considering contingencies related to CEO attributes and corporate governance mechanisms.

Design/methodology/approach

Using a sample of 131 companies from the Standard and Poor’s 500 index, this study employs fuzzy-set Qualitative Comparative Analysis (fs/QCA) to analyze combinations of conditions (i.e. configurations) that lead to greater ESG (i.e. environmental, social, and governance) performance.

Findings

Drawing on the upper echelon theory and the theory of social exchange, the findings show that different CEO’s political orientation (liberal/conservative) can contribute to ESG performance, depending on the combination of conditions. Furthermore, the results emphasize the importance of corporate political activity as a core condition to enhance ESG performance.

Originality/value

Taking a configurational approach, this study explores combinations of conditions that explain ESG performance, including CEO’s political orientation and corporate political activities as antecedent conditions. Unlike past research, this study examines possible complementarities between these two conditions and assumes that different CEO’s political orientation can have a positive influence on ESG performance, depending on the combination of conditions.

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Article
Publication date: 9 May 2020

Pedro Gaudencio, Arnaldo Coelho and Neuza Ribeiro

The study aims to show how organisational corporate social responsibility (CSR) can influence workers’ attitudes, especially in terms of turnover intentions (TI). A second aim is…

631

Abstract

Purpose

The study aims to show how organisational corporate social responsibility (CSR) can influence workers’ attitudes, especially in terms of turnover intentions (TI). A second aim is to explore the social exchange process that may underlie this relationship, by examining the mediating role of leader–member exchange (LMX) and the moderation role of perceived external prestige (PEP).

Design/methodology/approach

The authors use structural equation modelling based on survey data obtained from 315 Portuguese individuals.

Findings

The findings show that the perceptions of CSR predict TI through the mediating role of LMX. Seemingly PEP appears to be moderating the relationship between TI and its determinants. These findings suggest that managers should implement CSR practices because these can contribute towards reducing TI.

Originality/value

This study enriches the existing knowledge about relationships in organisational contexts and responds to the need of understanding the underlying mechanisms linking CSR with workers’ organisational outcomes, by analysing CSR practices in a holistic stakeholder perspective.

Details

Social Responsibility Journal, vol. 17 no. 4
Type: Research Article
ISSN: 1747-1117

Keywords

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