Browsing by Issue Date, starting with "2024-02-14"
Now showing 1 - 2 of 2
Results Per Page
Sort Options
- Moda Consciente e Bem-estarPublication . Miyoshi, Letícia Augusto Borges; Pereira, Maria Madalena Rocha; Fernandes, Solange RosaO presente trabalho visa aprofundar a compreensão da relação complexa entre moda e bem-estar, reconhecendo o paradoxo existente: enquanto as tendências de moda proporcionam auto expressão e autoestima, o seu consumo desenfreado gera, paralelamente, aflição e culpa, dada a notória pegada ambiental da indústria. Segundo dados da Organização das Nações Unidas, o aumento médio de consumo de vestimenta aumentou 60% em relação ao que era há 15 anos, enquanto o tempo de uso de cada peça diminuiu pela metade. Para entender essa realidade, foi utilizada uma metodologia não intervencionista, recorrendo a uma revisão bibliográfica abrangente através da abordagem de temas como pós-modernidade, sustentabilidade, comportamentos de consumo e tendências de mercado, a fim de explorar estratégias e soluções coletivas que promovam um consumo de moda mais consciente e de acordo com o bem-estar geral dos indivíduos. Conclui-se que a formação de comunidades pode ser um caminho a ser seguido, visto que desempenham um papel vital ao unir, educar, apoiar e capacitar os indivíduos a enfrentarem os desafios das mudanças climáticas e da instabilidade global. Por fim, foram analisados diversos serviços focados no bem-estar e no consumo de moda consciente cujos insights motivaram a idealização de um projeto único e inovador baseado na participação ativa da comunidade como forma de promover o consumo consciente de moda atrelado ao bem-estar físico, mental e do ambiente.
- Piezoresistive Sensing for Structural Health Monitoring of Multifunctional MWCNT-Reinforced Composites under Low-Velocity ImpactsPublication . Brito, Sérgio Daniel Fernandes; Pereira, João Pedro Nunes; Silva, Abílio Manuel Pereira da; Parente, João Miguel NunesFiber-reinforced composites have firmly established themselves as the preferred choice for designing and manufacturing high-performance structures, particularly in aeronautical and aerospace engineering. Despite the outstanding mechanical properties of these materials, their vulnerability to in-service damages, mainly due to low-velocity impacts, has driven the need for reliable structural health monitoring systems that can provide early indications of damage, ensuring the safety and longevity of composite structures in the aeronautical and aerospace industries. In this context, the core objective of this study is to develop a self-sensing glass fiber-reinforced composite with real-time damage detection capabilities tailored for low-velocity impact events. To achieve this, 0.5 wt% of multi-walled carbon nanotubes were added to the epoxy matrix to serve as piezoresistive sensors. Initially, the mechanical properties of the composites were assessed both before and after experiencing impacts of 3 J and 6 J energies, revealing a tangible enhancement in mechanical performance due to the incorporation of multi-walled carbon nanotubes. Subsequently, the investigation extended to the impact response and damage characterization of the specimens, uncovering notable distinctions in the degree of damage incurred under the two distinct impact energy levels. Afterward, the nano-enhanced specimens underwent controlled flexural loading conditions, simulating real-world mechanical stresses. The changes in electrical resistance of the specimens were monitored as a function of applied strain. The results obtained from monotonic and cyclic loading tests demonstrated a remarkable correlation between the mechanical strain and the corresponding change in electrical resistance (gauge factor of -0.40 for the non-impacted specimens), highlighting the inherent piezoresistive behavior of the material. Finally, the piezoresistive response of the specimens under 3 J and 6 J impact events validated its self-sensing capabilities for the real-time detection of low-velocity impacts. In summary, by adding 0.5 wt% of multi-walled carbon nanotubes to the epoxy matrix, it was possible to obtain a glass-fiber composite material that could act as a structural component and a strain sensor simultaneously, offering an effective and multifunctional solution for structural health monitoring applications.