Percorrer por autor "Duarte, Isabel"
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- A 3D-Printed Ceramics Innovative Firing Technique: A Numerical and Experimental StudyPublication . Santos, Tiago; Ramani, Melinda; Devesa, Susana; Batista, Catarina; Franco, Margarida; Duarte, Isabel; Costa, Luís; Ferreira, Nelson; Alves, Nuno; Pascoal-Faria, PaulaAdditive manufacturing (AM), also known as three-dimensional (3D) printing, allows the fabrication of complex parts, which are impossible or very expensive to produce using traditional processes. That is the case for dinnerware and artworks (stoneware, porcelain and clay-based products). After the piece is formed, the greenware is fired at high temperatures so that these pieces gain its mechanical strength and aesthetics. The conventional (gas or resistive heating elements) firing usually requires long heating cycles, presently requiring around 10 h to reach temperatures as high as 1200 °C. Searching for faster processes, 3D-printed stoneware were fired using microwave (MW) radiation. The pieces were fired within 10% of the conventional processing time. The temperature were controlled using a pyrometer and monitored using Process Temperature Control Rings (PTCRs). An error of 1.25% was calculated between the PTCR (1207 ± 15 °C) and the pyrometer (1200 °C). Microwave-fast-fired pieces show similar mechanical strength to the references and to the electrically fast-fired pieces (41, 46 and 34 (N/mm2), respectively), presenting aesthetic features closer to the reference. Total porosities of ~4%, ~5% and ~9% were determined for microwave, electrically fast-fired and reference samples. Numerical studies have shown to be essential to better understand and improve the firing process using microwave radiation. In summary, microwave heating can be employed as an alternative to stoneware conventional firing methods, not compromising the quality and features of the processed pieces, and with gains in the heating time.
- 3D-printed multisampling holder for microcomputed tomography applied to life and materials science researchPublication . Vasconcelos, Isabel; Franco, Margarida; Pereira, Mário; Duarte, Isabel; Ginjeira, António; Alves, NunoThe aim of this work was to design, fabricate, test and validate a 3D-printed multisampling holder for multi-analysis by microcomputed tomography. Different raw materials were scanned by microcomputed tomography. The raw material chosen was used to fabricate the holder by 3D printing. To validate the multisampling holder, five teeth were filled with a high density-material and scanned in two ways: a single and a multisampling scan mode. For each tooth, the root canal filling volume, porosity volume, closed pore volume, and open pore volume were calculated and compared when the same tooth was scanned in the two sampling scan mode. ABSplus P430™ allowed a high transmission value (84.3 %), and then it was the polymeric material selected to fabricate the holder. In a single sampling scan mode, the scan duration for scanning five teeth was 87.42 min, contrasting with 21.51 min for a multisampling scan mode, which scanned five teeth at the same time. The scan duration time and the cost using a multisampling holder represented a reduction of 75 % and the data volume generated represented a reduction of 60 %. Comparing the two scan modes, the results also showed that the difference of root canal filling volume, porosity volume, closed pore volume, and open pore volume was not statistically significant (p > .05). The multisampling holder was validated to do multi-analysis by microcomputed tomography without significant loss of quantitative accuracy data, allowing a reduction in scan duration time, imaging cost, and data storage.
- Additive manufactured stoneware fired in microwave furnacePublication . Santos, Tiago; Ramani, Melinda; Devesa, Susana; Batista, Catarina; Franco, Margarida; Duarte, Isabel; Costa, Luís; Ferreira, Nelson; Alves, Nuno; Pascoal-Faria, PaulaAdditive manufacturing (AM) techniques have revolutionized the concept of building parts not only in laboratory contexts but also in industry environments and can be applied to distinct fields such as the health, automotive and aeronautics sectors [...]
- PLAYER – a European Project and a Game to Foster Entrepreneurship Education for Young PeoplePublication . Fonseca, Benjamim; Morgado, Leonel; Paredes, Hugo; Martins, Paulo; Gonçalves, Ramiro; Neves, Pedro; Nunes, Ricardo Rodrigues; Lima, Jorge; Varajão, João; Pereira, Angela; Sanders, Robert; Barracho, Vera; Lapajne, Urban; Rus, Matej; Rahe, Martin; Mostert, Andre; Klein, Thorsten; Bojovic, Viktorija; Bošnjak, Saša; Bošnjak, Zita; Carvalho, João; Duarte, Isabel; Casaramona, Andreana; Soraci, AlbertoEntrepreneurship is widely recognized as one of the basic skills to be acquired through a life-long learning. The European Union, under the guidance of the Oslo Agenda, promotes several initiatives to develop entrepreneurship culture in Europe. Education can make a significant contribution to entrepreneurship, encouraging the development of ntrepreneurial attitudes and skills in young people. Serious Games are presently recognised as having an important role and potential in education and social networks emerged in the last years as the platform preferred by many, especially young people, to socialize, play games and even learn. This paper presents the PLAYER project, in which a game was developed and implemented as a Facebook application, to enable learning entrepreneurial skills progressively, by guiding users to develop a business idea in the form of a business plan.