Entradas recentes
Investigation of a recyclable flax–acrylic composite structure (FLACS) for construction applications
( 2026 ) Pereira, Rui; Antunes, Paulo Fernando Rocha; Uribe, Braian Esneider Buitrago
Sandwich composite structures combine high stiffness, mechanical strength and low weight, making them attractive for panel applications in construction. However, their limited reprocessability, arising from the use of thermoset matrices that cannot be remelted after crosslinking, restricts their recyclability and sustainable use. This study reports the development of a recyclable sandwich composite structure based on flax fibers and a liquid polymethyl methacrylate (PMMA) thermoplastic matrix (FLACS). The work includes the fabrication of the core and face sheets, as well as the complete sandwich structure, using a combination of resin infusion and compression molding techniques. Mechanical testing revealed a bending strength of 41 MPa, a compressive load capacity of 19.6 kN and an energy absorption of 14.1 J under low-velocity impact. With a density of 234 kg/m3, the material demonstrates high specific mechanical performance. FLACS was subsequently subjected to a single mechanical recycling cycle followed by thermo-mechanical processing, without the addition of virgin polymer. The results demonstrate the feasibility of recovering the material as feedstock for manufacturing new composite panels suitable for scalable construction applications.
Explaining turnover intention: The role of leadership in organizational contexts
( 2026 ) Sousa, Bruna; Gomes, A. Rui; Morais, Catarina; Dias-Oliveira, Eva; Araújo, Patrícia; Simães, C.
Leaders assume an important role in organizational success by influencing workers' attitudes and behaviors. The Leadership Efficacy Model (LEM) is a recent theoretical proposal focusing on factors that increase leadership efficacy. According to the LEM, three leadership factors can explain the efficacy of leadership: leadership cycles, leadership styles, and antecedent factors of leadership. This study explored the relationship between the congruence of leadership cycles and leadership efficacy (measured by turnover intention), analyzing whether leadership styles and antecedent factors of leadership moderate this relationship. The study included 842 participants evaluated in terms of leadership cycles, leadership styles, antecedent factors of leadership, and turnover intention. The results confirmed that congruence between the conceptual and practical cycles of leadership was associated with lower turnover intention and that the leadership styles were moderators of this relationship. These findings contribute to the leadership field and provide valuable insights for managing organizations.
Life skills in school health promotion: challenges and solutions
( 2026 ) Carvalho, Graça S.; Vilaça, Teresa; Magalhães-Júnior, Carlos A.; Darlington-Bernard, Adeline
The e-book on “Life skills in school health promotion: challenges and solutions” addresses the ongoing challenges in defining and understanding life skills within school health promotion and beyond. It aims at providing clarity and direction for policymakers, educators, and stakeholders striving to enhance health outcomes and the development of life skills among children, young people, adults and older people. The e-book comprises 25 papers: 9 explore health promotion and wellbeing, 8 examine mental health and emotional competencies, and 8 address physical activity.