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1 – 10 of 834Fabiana Turelli, David Kirk and Alexandre Fernandez Vaz
Martial arts and combat sports (MACS) are supported on ritualistic practices which often encompass hazing creating environments where catastrophic masculinities prevail. These…
Abstract
Martial arts and combat sports (MACS) are supported on ritualistic practices which often encompass hazing creating environments where catastrophic masculinities prevail. These forms of masculinities are strengthened inside MACS’ world resonating with masculinities spread out in wider society. We consider this to be the situation found in Brazilian society. With this study, our aim is to analyse how hazing practices in MACS contribute to the production of a socially legitimised catastrophic masculinity in Brazil. Catastrophic masculinity appears as a new concept proposed by Andrade (2022) to define a hegemonic, toxic and tragic form of masculinity spread in Brazil attached to a political power project. We carried out two qualitative empirical pieces of research that focused on three martial arts. These were ethnographic (participant-) observations of various events, training sessions, belt examination and competition and interviews with men participants. Supported by the presented data, we argue that hazing practices end up acting as a means of reproducing the catastrophic masculinity fighters perform in the dojo. They learn and resonate with a pedagogy that requires them to conform to and follow hierarchies through the repetition of the word ‘oss’ as a symbol of submission to arbitrariness. Hazing constitutes, instantiates and reproduces catastrophic masculinity and originates in the same (social) catastrophic masculinity.
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Manuel Sardinha, Luís Ferreira, Hermínio Diogo, Tânia R.P. Ramos, Luís Reis and M. Fátima Vaz
This study aims to investigate the tensile strength and compressive behaviour of two thermoplastic polyurethane (TPU) filaments produced via material extrusion (ME): TPU 95A and…
Abstract
Purpose
This study aims to investigate the tensile strength and compressive behaviour of two thermoplastic polyurethane (TPU) filaments produced via material extrusion (ME): TPU 95A and Reciflex (recycled).
Design/methodology/approach
Tensile strength and compressive behaviour are assessed. The influence of extrusion temperature and infill pattern on these properties is examined, supported by thermal characterization, surface morphology analyses and a comprehensive comparison with existing literature. An analytical method is presented for estimating the solid ratio of ME parts, using an ellipse model to describe the material bead geometry.
Findings
Reciflex is generally stiffer than TPU 95A in both tensile and compressive tests. Specimens loaded orthogonally in compression tests exhibited stiffer behaviour than those loaded parallelly, and higher tensile properties were typically observed when material beads were deposited parallel to the load direction. Unlike TPU 95A, Reciflex is sensitive to extrusion temperature variations.
Social implications
By comparing recycled and virgin TPU filaments, this research addresses waste management concerns and advocates for environmentally sustainable production practices in the broadly used filament/based ME technique.
Originality/value
This study provides an extensive comparison of computed values with existing literature, offering insights into how different materials may behave under similar processing conditions. Given ongoing challenges in controlling melt flow during extrusion, these results may offer insights for optimizing the production of ME parts made with thermoplastic elastomers.
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P.S.B. Zdanski, M. Vaz and G.R. Inácio
Numerical simulation of polymer injection processes has become increasingly common in mould design. In industry, such a task is accomplished mainly by using commercial packages…
Abstract
Purpose
Numerical simulation of polymer injection processes has become increasingly common in mould design. In industry, such a task is accomplished mainly by using commercial packages. Owing to the complexities inherent of this class of problems, most commercial codes attempt to combine realistic rheological descriptions with simplified numerical models. In spite of the apparent success, such approaches are not able to capture important aspects of the flow topology. The present work aims to describe a more elaborate mathematical model based on finite volumes which is able to provide both accurate solutions and further insights on the physics of the polymer flow.
Design/methodology/approach
The mathematical model comprises the momentum and energy equations and a Poisson equation for pressure to impose the incompressibility constraint. The governing equations are discretized using the finite volume method based on central, second‐order accurate formulas for both convection and diffusion terms. Artificial dissipation terms are added externally in order to control the odd‐even decoupling problem.
Findings
The numerical model was conceived within the framework of a generalized Newtonian formulation. The capability of the numerical scheme is illustrated by simulations using three distinct constitutive relations to approach the non‐Newtonian behaviour of the polymer melt: isothermal power‐law, modified Arrhenius power‐law and cross models.
Originality/value
This paper extends the computational strategies previously developed to Newtonian fluids to account for more complex constitutive relations. The velocity and temperature coupled solution for polymer melts using only second‐order accurate formulas constitute also a relevant contribution.
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M. Vaz Jr, E.L. Cardoso and J. Stahlschmidt
Parameter identification is a technique which aims at determining material or other process parameters based on a combination of experimental and numerical techniques. In recent…
Abstract
Purpose
Parameter identification is a technique which aims at determining material or other process parameters based on a combination of experimental and numerical techniques. In recent years, heuristic approaches, such as genetic algorithms (GAs), have been proposed as possible alternatives to classical identification procedures. The present work shows that particle swarm optimization (PSO), as an example of such methods, is also appropriate to identification of inelastic parameters. The paper aims to discuss these issues.
Design/methodology/approach
PSO is a class of swarm intelligence algorithms which attempts to reproduce the social behaviour of a generic population. In parameter identification, each individual particle is associated to hyper-coordinates in the search space, corresponding to a set of material parameters, upon which velocity operators with random components are applied, leading the particles to cluster together at convergence.
Findings
PSO has proved to be a viable alternative to identification of inelastic parameters owing to its robustness (achieving the global minimum with high tolerance for variations of the population size and control parameters), and, contrasting to GAs, higher convergence rate and small number of control variables.
Originality/value
PSO has been mostly applied to electrical and industrial engineering. This paper extends the field of application of the method to identification of inelastic material parameters.
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Climate change and crucial environmental issues, such as global warming, soil degradation and water pollution have incited concern over the natural environment and have provoked…
Abstract
Climate change and crucial environmental issues, such as global warming, soil degradation and water pollution have incited concern over the natural environment and have provoked both government and individual interventions in order to amplify constructive actions for environmental protection and restoration. Food is considered to be one of the most impactful consumption domains that substantially contribute to the overall carbon footprint. This chapter discusses the incentives and interventions oriented to support the transition to more sustainable agro-food systems. Furthermore, it provides a broader picture of stakeholders’ perceptions and adaptation to climate change uncertainties, as well as how climate change is perceived by consumers and how this may affect their food patterns, turning them to a more sustainable direction. Finally, a vocabulary of climate-related terms and a set of various exercises are presented, aiming to enhance students’ learning and critical thinking skills in the key role of the agro-food systems in climate change, sustainable development and environmental security.
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Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the…
Abstract
Gives a bibliographical review of the finite element methods (FEMs) applied for the linear and nonlinear, static and dynamic analyses of basic structural elements from the theoretical as well as practical points of view. The range of applications of FEMs in this area is wide and cannot be presented in a single paper; therefore aims to give the reader an encyclopaedic view on the subject. The bibliography at the end of the paper contains 2,025 references to papers, conference proceedings and theses/dissertations dealing with the analysis of beams, columns, rods, bars, cables, discs, blades, shafts, membranes, plates and shells that were published in 1992‐1995.
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Abdulkader Zairbani and Senthil Kumar Jaya Prakash
The purpose of this paper is to provide an organizing lens for viewing the distinct contributions to knowledge production from those research communities addressing the impact of…
Abstract
Purpose
The purpose of this paper is to provide an organizing lens for viewing the distinct contributions to knowledge production from those research communities addressing the impact of competitive strategy on company performance in general, and the influence of cost leadership and differentiation strategy on organizational performance in detail.
Design/methodology/approach
The research methodology was based on the PRISMA review, and thematic analysis based on an iterative process of open coding was analyzed and then the sample was analyzed by illustrating the research title, objectives, method, data analysis, sample size, variables and country.
Findings
The main factor that influenced the competitive strategy is strategic growth; strategic growth has a significant influence on competitive strategy. Furthermore, competitive strategy will boost firm network, performance measurement and organization behavior. In the same way, the internal goal factor will enhance organizational effectiveness. Also, a differentiation strategy will support management practice factors, strategic positions, product price, product characteristics and company performance.
Originality/value
This study contributes to the literature by identifying a framework of competitive strategy factors, company performance factors, cost leadership strategy factors, differentiation strategy factors and competitive strategy with global market factors. This study provides a complete picture and description of the resulting body knowledge in competitive strategy and organizational performance.
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Guilherme Duarte, Ana M.A. Neves and António Ramos Silva
The goal of this work is to create a computational finite element model to perform thermoelastic stress analysis (TSA) with the usage of a non-ideal load frequency, containing the…
Abstract
Purpose
The goal of this work is to create a computational finite element model to perform thermoelastic stress analysis (TSA) with the usage of a non-ideal load frequency, containing the effects of the material thermal properties.
Design/methodology/approach
Throughout this document, the methodology of the model is presented first, followed by the procedure and results. The last part is reserved to results, discussion and conclusions.
Findings
This work had the main goal to create a model to perform TSA with the usage of non-ideal loading frequencies, considering the materials’ thermal properties. Loading frequencies out of the ideal range were applied and the model showed capable of good results. The created model reproduced acceptably the TSA, with the desired conditions.
Originality/value
This work creates a model to perform TSA with the usage of non-ideal loading frequencies, considering the materials’ thermal properties.
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Daniele Cinque, Jose Viriato Araujo dos Santos, Stefano Gabriele, Sonia Marfia and Hernâni Lopes
The purpose of this paper is to present a study on the application of four damage factors to several single and multiple damage scenarios of aluminium beams. Each one of these…
Abstract
Purpose
The purpose of this paper is to present a study on the application of four damage factors to several single and multiple damage scenarios of aluminium beams. Each one of these damage factors is defined by the information given by modal curvatures of the beams.
Design/methodology/approach
The methodology consisted of a first experimental stage in which the modal rotations were measured with shearography and a subsequent numerical analysis in order to obtain the modal curvatures. To this end, three finite difference formulae were applied. The modal curvatures were then used to calculate the damage factors.
Findings
It was found that the profile of the damage factors varies according to the finite difference formula used. In view of the findings, the differences among the damage factors analysed are highlighted and some final recommendations to improve damage identifications via modal curvature-based are presented.
Originality/value
To the best of the authors’ knowledge, the application and comparison of several finite difference formulae and corresponding optimal sampling has not been carried out before. With the proposed approach, it is possible to identify multiple damages, which is still a great challenge. The post-processing of shearography measurements with a numerical method, which is inherently a multidisciplinary approach, is also a substantial improvement upon other type of approaches found in the literature.
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