Percorrer por data de Publicação, começado por "2025-02-19"
A mostrar 1 - 2 de 2
Resultados por página
Opções de ordenação
- Head-to-Head Evaluation of FDM and SLA in Additive Manufacturing: Performance, Cost, and Environmental PerspectivesPublication . Abbasi, Maryam; ANTUNES VAZ, PAULO JOAQUIM; Martins, Pedro; Silva, JoséThis paper conducts a comprehensive experimental comparison of two widely used additive manufacturing (AM) processes, Fused Deposition Modeling (FDM) and Stereolithography (SLA), under standardized conditions using the same test geometries and protocols. FDM parts were printed with both Polylactic Acid (PLA) and Acryloni trile Butadiene Styrene (ABS) filaments, while SLA used a general-purpose photopolymer resin. Quantitative evaluations included surface roughness, dimensional accuracy, ten sile properties, production cost, and energy consumption. Additionally, environmental considerations and process reliability were assessed by examining waste streams, recy clability, and failure rates. The results indicate that SLA achieves superior surface quality (Ra ≈ 2 µm vs. 12–13 µm) and dimensional tolerances (±0.05 mm vs. ±0.15–0.20 mm), along with higher tensile strength (up to 70 MPa). However, FDM provides notable ad vantages in cost (approximately 60% lower on a per-part basis), production speed, and energy efficiency. Moreover, from an environmental perspective, FDM is more favorable when using biodegradable PLA or recyclable ABS, whereas SLA resin waste is hazardous. Overall, the study highlights that no single process is universally superior. FDM offers a rapid, cost-effective solution for prototyping, while SLA excels in precision and surface finish. By presenting a detailed, data-driven comparison, this work guides engineers, product designers, and researchers in choosing the most suitable AM technology for their specific needs.
- “What Does Gerotranscendence Mean to You?” Older Adults’ Lay Perspectives on the TheoryPublication . Abreu, Taiane; Araújo, Lia; Teixeira, Laetitia; Ribeiro, OscarBackground and Objectives: Gerotranscendence, a recent adaptive aging theory developed by Tornstam, postulates a mindset shift in old age from a materialistic viewpoint to a more transcendent one. Gerotranscendence is considered a promising aging model, as it approaches specific developmental challenges in late life. However, knowledge of this theory is still maturing and lacks laypersons’ perspectives to further validate its components. This study aimed to explore how older adults perceive gerotranscendence and gain insights of their understanding. Research Design and Methods: Three focus group discussions were conducted with 18 participants (59–98 years old; mean: 79.5 years). The protocol included open-ended questions on what gerotranscendence, and its dimensions meant (based exclusively on their designations), as well as on the theory’s components (after further explanation). The discussions were recorded and transcribed, and a content analysis was performed. Results: The data were organized into 2 themes: general suppositions and personal perceptions. This second theme was divided into (i) relatable thoughts and experiences and (ii) a different and complementary understanding of the theory. Discussion and Implications: Despite the lack of knowledge of the meaning of gerotranscendence, older persons presented clear evidence that this topic was meaningful for them and that they experienced aspects of the cosmic, coherence, and solitude dimensions of gerotranscendence. However, at specific points, some participants had distinctive and complementary ideas compared with those espoused by gerotranscendence theory. Obtaining laypersons’ perspectives provides a more in-depth understanding of gerotranscendence theory and the cultural aspects it may encompass.