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- Non-Destructive Testing Inspection for Metal Components Produced Using Wire and Arc Additive ManufacturingPublication . Serrati, Douglas S. M.; Machado, Miguel A.; Oliveira, J. P.; Santos, Telmo G.; DEMI - Departamento de Engenharia Mecânica e Industrial; UNIDEMI - Unidade de Investigação e Desenvolvimento em Engenharia Mecânica e Industrial; CENIMAT-i3N - Centro de Investigação de Materiais (Lab. Associado I3N); DCM - Departamento de Ciência dos Materiais; MDPI - Multidisciplinary Digital Publishing InstituteThe wire and arc additive manufacturing (WAAM) process enables the creation and repair of complex structures based on the successive deposition of fed metal in the form of a wire that is fused with an electric arc and then solidifies. The high number of depositions required to create or repair parts increases the likelihood of defect formation. If these are reliably detected during manufacturing, timely correction is possible. However, high temperatures and surface irregularity make inspection difficult. Furthermore, depending on the size, morphology, and location of the defect, the part can be rejected. Recent studies have shown that non-destructive testing (NDT) based on different physical phenomena for the timely, reliable, and customized detection of defects can significantly reduce the rejection rate and allow in-line repair, which consequently reduces waste and rework. This paper presents the latest developments in NDT for WAAM and its limitations and potential.
- Prototype of an affordable pressure-controlled emergency mechanical ventilator for COVID-19Publication . Pereira, Américo; Lopes, Luís; Fonte, Paulo; Póvoa, Pedro; Santos, Telmo G.; Martinho, Alberto José Antunes Marques; Neves, Ângela; Bugalho, António A.; Gabriel-Santos, António; Pimenta, Gonçalo Gaspar Bentes; Goes, João Carlos da Palma; Martins, João F.; Oliveira, João Pedro Abreu de; Santos, José Paulo; Gil, Luís Miguel Chagas da Costa; Domingues, Miguel Onofre; Cunha, Orlando; de Sousa, Pedro Pinheiro; Rodrigues, Tiago A.; Duarte, Valdemar Rebelo; Abrunhosa, Antero; Grilo, António; do Nascimento, João Agostinho; Pimenta, Mário; Comprehensive Health Research Centre (CHRC) - pólo NMS; Centro de Estudos de Doenças Crónicas (CEDOC); NOVA Medical School|Faculdade de Ciências Médicas (NMS|FCM); DEMI - Departamento de Engenharia Mecânica e Industrial; UNIDEMI - Unidade de Investigação e Desenvolvimento em Engenharia Mecânica e Industrial; UNINOVA-Instituto de Desenvolvimento de Novas Tecnologias; DEE2010-A2 Electrónica; DEE - Departamento de Engenharia Electrotécnica e de Computadores; CTS - Centro de Tecnologia e Sistemas; DEE2010-B1 Energia; DF – Departamento de Física; LIBPhys-UNLWe present a viable prototype of a simple mechanical ventilator intended as a last resort to ventilate COVID-19 patients. The prototype implements the pressure-controlled continuous mandatory ventilation mode (PC-CMV) with settable breathing rates, inspiration/expiration time ratios and FiO2 modulation. Although safe, the design aims to minimize the use of technical components and those used are common in industry, so its construction may be possible in times of logistical shortage or disruption or in areas with reduced access to technical materials and at a moderate cost, affordable to lower income countries. Most of the device can be manufactured by modest technical means and construction plans are provided.
- Industrial applications of power electronicsPublication . Rodrigues, Eduardo M. G.; Godina, Radu; Pouresmaeil, Edris; UNIDEMI - Unidade de Investigação e Desenvolvimento em Engenharia Mecânica e Industrial; DEMI - Departamento de Engenharia Mecânica e Industrial; MDPI - Multidisciplinary Digital Publishing InstituteElectronic applications use a wide variety of materials, knowledge, and devices, which pave the road to creative design, development, and the creation of countless electronic circuits with the purpose of incorporating them in electronic products. Therefore, power electronics have been fully introduced in industry, in applications such as power supplies, converters, inverters, battery chargers, temperature control, variable speed motors, by studying the effects and the adaptation of electronic power systems to industrial processes. Recently, the role of power electronics has been gaining special significance regarding energy conservation and environmental control. The reality is that the demand for electrical energy grows in a directly proportional manner with the improvement in quality of life. Consequently, the design, development, and optimization of power electronics and controller devices are essential to face forthcoming challenges. In this Special Issue, 19 selected and peer-reviewed papers discussing a wide range of topics contribute to addressing a wide variety of themes, such as motor drives, AC-DC and DC-DC converters, electromagnetic compatibility and multilevel converters.
- Correction to: Elemental Effects on Weld Cracking Susceptibility in Al xCoCrCu yFeNi High-Entropy Alloy (Metallurgical and Materials Transactions A, (2020), 51, 2, (778-787), 10.1007/s11661-019-05564-8)Publication . Martin, Alexander C.; Oliveira, João Pedro; Fink, Carolin; DEMI - Departamento de Engenharia Mecânica e Industrial; SpringerTHE Acknowledgments in the original article are incomplete. Following is the updated text. This work was supported by the Institute of Materials Research (IMR) at The Ohio State University (OSU), and by the American Welding Society (AWS) Foundation. The authors also express their gratitude to Brady Soulivong, a high school student in the OSU Intern Program, which is hosted by the National Science Foundation IUCRC Materials and Manufacturing Innovation Research Center (Ma2JIC). Electron microscopy was performed at the Center for Electron Microscopy and Analysis (CEMAS) at The Ohio State University.
- Sustainable energy systems: Optimization and efficiencyPublication . de Oliveira Matias, João Carlos; Godina, Radu; Pouresmaeil, Edris; UNIDEMI - Unidade de Investigação e Desenvolvimento em Engenharia Mecânica e Industrial; DEMI - Departamento de Engenharia Mecânica e Industrial; MDPI - Multidisciplinary Digital Publishing InstituteThe world population is growing at a very high rate, which also entails a massive increase in energy consumption, and also, therefore, in its production, which is gradually and steadily increasing. Energy and the environment are essential to achieving sustainable development, and constitute a fundamental part of human activity. If we consider energy efficiency as the use of an appliance, process or installation for which we try to produce more energy, but with less energy consumption than the average for these appliances, processes or installations, then achieving a higher energy efficiency is imperative. Energy efficiency is a cornerstone policy on the road to stopping climate change and to achieving sustainable societies, along with the development of renewable energy and an environmentally friendly transport policy. In this Special Issue, 11 selected and peer-reviewed articles have been contributed, on a wide range of topics under the umbrella of sustainable energy systems. The published articles encompass distinct areas of interest. One area addresses distributed generation, which addresses such topics as the optimal planning of distributed generation, protection of blind areas in distribution networks, multi-objective optimization in distributed generation, energy management of virtual power plants in distributed generation, and the impact of demand-response programs on a home microgrid, as well as concentrating solar power into a highly renewable, penetrated power system. The second section of the Special Issue addresses a wide range of topics, from parametric studies of 2 MW gas engines or data centers, to combustion characteristics of a non-premixed oxy-flame, to new techniques of PV Tracking, to applications of nanofluids in the thermal performance enhancement of parabolic trough solar collectors.
- Laser weldingePublication . Oliveira, J. P.; Zeng, Zhi; DEMI - Departamento de Engenharia Mecânica e Industrial; UNIDEMI - Unidade de Investigação e Desenvolvimento em Engenharia Mecânica e Industrial; Elsevier Science B.V., Amsterdam.
- Fundamentos de Axiomatic Design: Parte 7 – A Reangularidade e a Semangularidade Segundo a Teoria Axiomática de ProjetoPublication . Navas, Helena V. G.; UNIDEMI - Unidade de Investigação e Desenvolvimento em Engenharia Mecânica e Industrial; DEMI - Departamento de Engenharia Mecânica e Industrial; Vida Económica
- Occupational safety and health in the wind energy sector - European Risk ObservatoryPublication . Webster, Jennifer; Cabeças, José Martin Miquel; Kuhl, Klaus; Liddle, Mark; Ellwood, Peter; Smith, Phoebe; Gervais, Roxane; Bradbrook, Samuel Dylan; Väänänen, Virpi; DEMI - Departamento de Engenharia Mecânica e Industrial