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Article

Juan Antonio Campos Soria and Luis Robles Teigeiro

The purpose of this study was to estimate the capacity of the predominant activity of the Hotel and Restaurant (H&R) sector to create female employment in European Union…

Abstract

Purpose

The purpose of this study was to estimate the capacity of the predominant activity of the Hotel and Restaurant (H&R) sector to create female employment in European Union (EU) countries.

Design/methodology/approach

The methodology used was conducted in two stages. First, a branch employment multiplier was calculated using the Leontief input-output tables (IOTs), which show the direct and indirect capacity of the activity to generate female employment. Second, a regression model was estimated to explain the determinants of the female employment multiplier in the H&R sector. It should be noted that the reliability and simplicity of the proposed model allows countries without IOTs, but with gender-disaggregated labor statistics, to easily estimate their own female employment multiplier.

Findings

The results show that the job-creation capacity of the H&R sector significantly varies across the EU countries, especially in relation to the female employment multiplier. Although international differences in gender wage gaps help to explain such multipliers, institutional factors and feminization rate also play a key role.

Research limitations/implications

The results may contribute to improving the actions of member states to stimulate the sustainable development of the tourism sector.

Originality/value

Based on previous literature, the finding that higher tourism expenditure may result in increases in tourism employment gives rise to another set of interesting questions. The most fundamental of these may concern the nature of the economic underpinnings of the growth of female employment. This paper contributes to this issue by conducting a specific analysis across EU countries using a homogenous and comparable methodology.

Details

International Journal of Contemporary Hospitality Management, vol. 31 no. 1
Type: Research Article
ISSN: 0959-6119

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Article

Antonio Campo and Yunesky Masip

The purpose of this study is to address one-dimensional, unsteady heat conduction in a large plane wall exchanging heat convection with a nearby fluid under “small time”…

Abstract

Purpose

The purpose of this study is to address one-dimensional, unsteady heat conduction in a large plane wall exchanging heat convection with a nearby fluid under “small time” conditions.

Design/methodology/approach

The Transversal Method of Lines (TMOL) was used to reformulate the unsteady, one-dimensional heat conduction equation in the space coordinate and time into a transformed “quasi-steady”, one-dimensional heat conduction equation in the space coordinate housing the time as an embedded parameter. The resulting ordinary differential equation of second order with heat convection boundary conditions is solved analytically with the method of undetermined coefficients.

Findings

Semi-analytical TMOL dimensionless temperature profiles of compact form with/without regressed terms are obtained for the whole spectrum of Biot number (0 < Bi < ∞) in the “small time” sub-domain. In addition, a new “large time” sub-domain is redefined, that is, setting a smaller critical dimensionless time or critical Fourier number τcr = 0.18.

Originality/value

The computed dimensionless center, surface and mean temperature profiles in the large plane wall accounting for all Biot number (0 < Bi < ∞) in the “small time” sub-domain τ < τcr = 0.18 exhibit excellent quality while carrying reasonable relative errors for engineering applications. The exemplary level of accuracy indicates that the traditional evaluation of the center, surface and mean temperatures with the standard infinite series retaining a large number of terms is no longer necessary.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 29 no. 2
Type: Research Article
ISSN: 0961-5539

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Book part

Alexandre F. S. Andrada and Mauro Boianovsky

This chapter investigates the political and economic contexts of the controversy about the causes of the increase of income concentration in Brazil during the 1960s. That…

Abstract

This chapter investigates the political and economic contexts of the controversy about the causes of the increase of income concentration in Brazil during the 1960s. That was the most important economic debate that took place under the military dictatorship that ran the country from 1964 to 1985. The perceived sharp increase in income inequality posed a challenge to the economic legitimation of the military regime, which had by the early 1970s achieved high rates of economic growth. This chapter discusses the apparent paradox of relatively open economic debate during a period of political repression, as well as its international dimension as reflected in the role played by institutions such as the World Bank.

Details

Research in the History of Economic Thought and Methodology: Including a Symposium on Economists and Authoritarian Regimes in the 20th Century
Type: Book
ISBN: 978-1-83867-703-9

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Article

Antonio Campo and Juan C. Morales

This paper presents a simple computational procedure for the laminar,fully established velocity and temperature in straight ducts with irregular,singly connected…

Abstract

This paper presents a simple computational procedure for the laminar, fully established velocity and temperature in straight ducts with irregular, singly connected cross‐sections by virtue of a control volume discretization of the momentum and energy equations in boundary‐fitted co‐ordinate systems. The combined procedure has been applied to a large group of ducts whose cross‐sections possess different levels of difficulty. The numerical predictions for the pressure drop (friction factor) and the convective heat transfer coefficient (Nusselt number) have been reported for a sub‐class of ducts with curved sides and sharp corners utilizing various grid sizes.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 6 no. 6
Type: Research Article
ISSN: 0961-5539

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Article

Lourdes Campos and Antonio Gonzalez

A new method to solve zero‐sum two‐person games with imprecise values in their matrices of pay‐offs is suggested. The natural lack of precision generated by the use of…

Abstract

A new method to solve zero‐sum two‐person games with imprecise values in their matrices of pay‐offs is suggested. The natural lack of precision generated by the use of fuzzy numbers in a fuzzy game requires the use of subjective criteria by the players in the resolution model. We apply a ranking function, the Average Value, which allows the decision makers to take into account their subjectivity. The use of this function raises again the solution of the fuzzy game when two criteria, one for each player, are used.

Details

Kybernetes, vol. 20 no. 1
Type: Research Article
ISSN: 0368-492X

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Article

António A.M.A. Campos, Abílio M.P. de Jesus, José A.F.O. Correia and José J.L. Morais

Adhesively bonded joints are gaining importance in the structural joining processes competing against welding and bolting processes. However, long-term behaviour of…

Abstract

Purpose

Adhesively bonded joints are gaining importance in the structural joining processes competing against welding and bolting processes. However, long-term behaviour of adhesively bonded joints is still an open question. Due to the increasing interest in adhesively bonded joints, mainly in the transports industry, there is a need to deep the knowledge about the fatigue behaviour of adhesive joints with metallic substrates allowing the development of reliable joints to resist cyclic loadings. The paper aims to discuss these issues.

Design/methodology/approach

An experimental research aiming at characterizing the fatigue behaviour of adhesively bonded aluminium substrates is presented in this paper, covering both fatigue crack propagation and global S-N behaviours. Double cantilever beam (DCB), end notch flexure (ENF) and double lap joints (DLJ) specimens built using the AA6061T651 substrate and epoxy adhesive were used to evaluate the pure modes I and II fatigue crack propagation rates and the S-N fatigue behaviours.

Findings

DCB and ENF specimens allowed the formulation of pure modes I and II fatigue crack propagation laws including the propagation thresholds. DLJs showed higher static shear strength than recommended by the manufacturer for aluminium substrates, but fatigue resistance of the DLJs was lower than suggested by the manufacturer. The fatigue damage process in the DLJs was dominated by a fatigue crack initiation process.

Originality/value

A consistent fatigue research on adhesively bonded aluminium substrates is presented covering in the same study aspects of fatigue crack propagation and fatigue crack initiation. Data reduction schemes involving both numerical and analytical procedures were followed. Proposed work constitutes a rigorous basis for future fatigue prediction models developments.

Details

International Journal of Structural Integrity, vol. 8 no. 6
Type: Research Article
ISSN: 1757-9864

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Article

Antonio Campo, Abraham J. Salazar, Diego J. Celentano and Marcos Raydan

The purpose of this paper is to address a novel method for solving parabolic partial differential equations (PDEs) in general, wherein the heat conduction equation…

Abstract

Purpose

The purpose of this paper is to address a novel method for solving parabolic partial differential equations (PDEs) in general, wherein the heat conduction equation constitutes an important particular case. The new method, appropriately named the Improved Transversal Method of Lines (ITMOL), is inspired in the Transversal Method of Lines (TMOL), with strong insight from the method of separation of variables.

Design/methodology/approach

The essence of ITMOL revolves around an exponential variation of the dependent variable in the parabolic PDE for the evaluation of the time derivative. As will be demonstrated later, this key step is responsible for improving the accuracy of ITMOL over its predecessor TMOL. Throughout the paper, the theoretical properties of ITMOL, such as consistency, stability, convergence and accuracy are analyzed in depth. In addition, ITMOL has proven to be unconditionally stable in the Fourier sense.

Findings

In a case study, the 1-D heat conduction equation for a large plate with symmetric Dirichlet boundary conditions is transformed into a nonlinear ordinary differential equation by means of ITMOL. The numerical solution of the resulting differential equation is straightforward and brings forth a nearly zero truncation error over the entire time domain, which is practically nonexistent.

Originality/value

Accurate levels of the analytical/numerical solution of the 1-D heat conduction equation by ITMOL are easily established in the entire time domain.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 24 no. 7
Type: Research Article
ISSN: 0961-5539

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Article

El Hassan Ridouane and Antonio Campo

Sets out to discuss laminar free convection characteristics of air confined to a square cavity and a horizontal rectangular cavity (aspect ratio A=2) along with the viable…

Abstract

Purpose

Sets out to discuss laminar free convection characteristics of air confined to a square cavity and a horizontal rectangular cavity (aspect ratio A=2) along with the viable isosceles triangular cavities and right‐angle triangular cavities that may be inscribed inside the two original cavities.

Design/methodology/approach

The three distinct cavities shared the base wall as the heated wall, while the remaining sides and upper walls are cold. The finite volume method is used to perform the numerical computation of the transient conservation equations of mass, momentum and energy. The methodology takes into account the second‐order‐accurate quick scheme for the discretization of the convective term, whereas the pressure‐velocity coupling is handled with the simple scheme. The working fluid is air, which is not assumed as a Boussinesqian gas, so that all influencing thermophysical properties of air are taken as temperature‐dependent. The cavity problem is examined over a variety of height‐based Grashof numbers ranging from 103 to 106.

Findings

Numerical results are reported for the velocity fields, the temperature field as well as the local and mean wall heat fluxes along the heated base wall. It was found that the airflow remains symmetric for the isosceles triangular cavity with aspect ratio A=1 even at high Grashof numbers. In contrast, for an isosceles triangular cavity with an aspect ratio A=2, a pitchfork bifurcation begins to form at a critical Grashof number of 2 × 105, breaking the airflow symmetry. The computed local and mean heat fluxes along the hot base wall are compared for the three configurations under study and the corresponding maximum heat transfer levels are clearly identified for the two aspect ratios A=1 and 2.

Research limitations/implications

As a continuity of this work, there are two avenues that future research could explore and indeed are presently being explored by the authors within these geometries. The first deals with heat transfer enhancement using mixture of gases. The second is to re‐examine the problem under turbulent conditions.

Originality/value

The present study seeks to maximize the convection heat transport in cavities and minimize their sizes. The peculiarity of the derived cavities is their cross‐section area being half of the cross‐section area of the basic cavities.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 16 no. 3
Type: Research Article
ISSN: 0961-5539

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Article

Antonio Campo, Bernardo Hernández‐Morales and Ulises Lacoa

To provide a suitable linkage of a computational fluid dynamics code and a shape optimization code for the augmentation of local heat transfer coefficients in forced…

Abstract

Purpose

To provide a suitable linkage of a computational fluid dynamics code and a shape optimization code for the augmentation of local heat transfer coefficients in forced convection channels normally used in the cooling of electronic equipment.

Design/methodology/approach

A parallel‐plate channel with a discrete array of heat sources embedded in one wall, while the other wall is insulated, constitutes the starting model. Using water as coolant, the objective is to optimize the shape of the channel employing a computerized design loop. The two‐part optimization problem is constrained to allow only the unheated wall to deform, while keeping the same inlet shape and observing a maximum pressure drop constraint.

Findings

First, the results for the linearly deformed unheated wall show significant decrease compared with the wall temperatures of the heated wall, with the maximum wall temperature occurring slightly upstream of the outlet. Second, when the unheated wall is allowed to deform nonlinearly, a parabolic‐like shaped wall is achieved where the maximum wall temperature is further reduced, with a corresponding intensification in the local heat transfer coefficient. The effectiveness of the computerized design loop is demonstrated in complete detail.

Originality/value

This paper offers a simple technique for optimizing the shapes of forced convection channels subjected to pre‐set design constraints.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 16 no. 3
Type: Research Article
ISSN: 0961-5539

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Article

Antonio Campo, Biagio Morrone and Salah Chikh

It is undeniable that the annular fin of hyperbolic profile with constant thermal conductivity and uniform convective coefficient is important in many applications of heat…

Abstract

It is undeniable that the annular fin of hyperbolic profile with constant thermal conductivity and uniform convective coefficient is important in many applications of heat transfer engineering. The importance of this fin configuration stems from its close resemblance to the annular fin of optimal cross section capable of delivering maximum heat transfer for a given volume of material. This paper addresses two simple numerical procedures for solving the generalized Bessel equation that governs the temperature variation in annular fins of hyperbolic profile, one is the finite‐difference technique with an uncharacteristic coarse mesh and the other is the shooting method. Certainly, the central objective here is to avoid the evaluation of the elegant, but intricate exact analytic temperature distributions and companion fin efficiencies containing modified Bessel functions of fractional order.

Details

International Journal of Numerical Methods for Heat & Fluid Flow, vol. 14 no. 8
Type: Research Article
ISSN: 0961-5539

Keywords

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