IPS - ESTS – DSI - Capítulos em livros
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- Development of a large size 3D delta printer for advanced polymersPublication . Pereira, D.; Leite, M.; Ferreira, M.; Machado, D.; V. Dionísio, R.; Cláudio, R. A.Additive Manufacturing has been extensively used in the last years for prototyping and small series production of functional parts. One of the most popular processes is material extrusion, where a material is extruded through a nozzle, being the part created layer by layer. In this work, an advanced 3D printer is presented, build by the authors, based in a Delta Robot configuration, able to produce parts with 400 mm diameter and up to 850 mm height. The chosen concept provides a very stiff structure with ease of access to all components. A high temperature water-cooled print head (that can reach 500 °C) and a closed heated chamber makes this printer able to produce large size parts with some advanced thermoplastic materials. To improve accuracy, a new sensor based in a load cell with specific signal conditioning is proposed for z-probe and to accurately determine some characteristics of the Delta mechanism. The principal features of this new sensor are compared with a previous assembled sensor (IR). A careful assembly and non-clearance mechanisms with the new sensor proposed are expected to improve print quality.
- An exploratory study for the implementation of the oxidative potential assessment of particulate matter in PortugalPublication . Vicente, C.; Gonçalves, S.; Gamelas ou Carla A. Gamelas, Carla; Almeida, S. M.; Cabo Verde, S.; Bartolomeo, A. R.; Guascito, M. R.; Contini, D.; Canha, N.Particulate matter (PM) is a harmful air pollutant that damages human health by inducing oxidative stress through the excessive generation of reactive oxygen species (ROS). Oxidative Potential (OP) is a proposed metric to measure PM's capacity to generate ROS (Almetwally et al., 2020; Jiang et al., 2019). This study aims to implement the OPDTT assessment methodology at C2TN (Portugal). A set of PM2.5 samples was evaluated using a widely used protocol (Chirizzi et al., 2017), and the results were compared to the values previously obtained at DISTEBA, where the protocol is well established. Moreover, the use of the reference material SRM 1648 (Urban Particulate) as a standard for determining OPDTT was also evaluated. Analyzing a 10 mg.L-1 solution of the reference material, it was possible to conclude that the standard solution presented an average DTT activity (normalized to the mass) value of 27.60 ± 3.79 pmol.min-1.μg-1.
- The meaning of life (in video games)Publication . Mourato, Fausto; Morais, João; Lima, Edirlei Soares deThis paper explores how the concept of life has been used in video games through time. Life is an essential element in different types of action games and several nuances have been used to provide various types of emotions and effects during gameplay. However, the details and patterns have not been extendedly analyzed. Primarily, we survey works regarding the description and formalization of game analysis with emphasis on works in which the concepts have impact in the arguably accepted notion of life. Multiple examples are provided to show different approaches to the concept of life and the impact of such approaches in overall gameplay, namely in the game difficulty and emotions. The examples are then generalized, resulting in a proposal of framework to describe life representation in games. The proposed framework was evaluated in a user study, having participants with gaming culture (professionals, academics, and students of game development courses). Each participant was assigned with the task of fitting a preselected set of games within the framework. The results indicate good coverage of the main concepts with satisfactory consistency
- Transitioning the Teaching/Learning Process to Online Environment During the COVID-19 PandemicPublication . Miranda, P.; Rafael, Silviano; Justino, JúliaThe adaptation of both teachers and students to the application of pedagogical techniques in remote teaching/learning platforms of a Portuguese technology and engineering school of a higher education institution, due to the confinement imposed by the safety measures taken against the COVID-19 pandemic, is presented in this paper. The teachers’ behavior and students’ attitude concerning the change to remote teaching and learning methods is analysed. The actions taken, the difficulties experienced by the academic community in the transition from face-to-face to remote education, in particular the changeover of technical-scientific and pedagogical components in the course units, the evaluation of the teaching-learning process and the improvement needs are presented. Considerations on possible solutions and some relevant conclusions are also pointed out, showing that both teachers and students are not ready to switch to new digital means of education.
- Estudo de patentes de tecnologias de produção de ostras em aquaculturaPublication . Mata, A. M. T.; Salgado, R.
- Revisiting human relativism: guidelines for precision in information systems modellingPublication . CordeiroHuman Relativism (HR) was presented a decade ago as a new philosophical stance for thinking and modelling Information Systems. The Normative Approach for Modelling Information Systems (NOMIS) adopted HR by using a human-observable-action centred perspective of information systems. By using HR, NOMIS claims to have reduced unpredictability, attributed to human behaviour, and increased precision, required by formal methods. Still, there are other approaches, some of them using formal methods, supported by different ontologies, such as the well-known Bunge–Wand–Weber ontology, that lack the necessary precision. In this paper, we explore different ontologies, their relationship to language and why they fail to deliver precision. Precision, a concept introduced in HR, as a basis for engineering, is analysed, and the way to achieve it is proposed through suggesting guidelines for further discussion and research.
- Avaliação da eficácia da biorremediação em termos de remoção da ecotoxicidade associada ao sedimento SEMAPublication . Gonçalves, Odete; Almeida, Paulo Fernando de; Quintella, Cristina; Mata, A. M. T.Na problemática da indústria de produção pode-se citar os resíduos gerados e sua destinação ao meio ambiente, consequentemente a contaminação ambiental como a indústria de mineração na geração de resíduos minerais. Houve um acidente com rompimento da Barragem de Fundão, de rejeitos de mineração de ferro, no município de Mariana/MG. Foram utilizados para no processo de biorremediação os rejeitos de mineração com um consórcio microbiano no qual se obteve o sedimento biorremediado e os produtos biopolímero, cristais residuais. Após caracterização se avalia aqui a eficácia da biorremediação e validação do processo e produto com teste de ecotoxicologia a fim de viabilizar estes ou seus compostos moleculares para o setor industrial, fármacos, cosméticos, petrolífero e compósitos e de serviços/processos, conforme sua aplicação. Neste contexto, este trabalho avalia a inibição do crescimento das microalgas Pseudokirchneriella subcapitata com as amostras estudadas. Foram feitos cinco testes no rejeito de mineração em culturas triplicatas e em ambiente estéril. A leitura da absorvência a 450 nm em espectrofotómetro na gama UV-VIS com o período do teste por 72:00h. Se aplicou a equação DESVPAD com o cálculo. A microalga Pseudokirchneriella subcapitata apresentou 51% de redução da ecotoxicidade no sedimento biorremediado rejeito de mineração SEMA. Confirma assim, menor toxicidade, o que se torna importante para a validação do processo de biorremediação e atende aos principais requisitos para o desenvolvimento sustentável.
- The potential of biodiesel production from WWTP wastesPublication . Salgado, R. M.; Mata, A. M. T.; Epifâneo, L.; Barreiros, A. M.
- Improved PWM A/D conversion technique: working principle and model validationPublication . Pereira, José Miguel Costa DiasAnalog-to-digital conversion plays a central role in any application of digital sensors and sensor systems that require an interface between analog devices, namely analog sensors, and digital devices, namely, microprocessors, digital signal processors or microcontrollers. With the advent of smart sensing, the integration of signal conditioning, analog-to-digital and digital data processing in single hardware devices became a reality. Moreover, the usage of low-cost discrete A/D conversion techniques for applications that are not critic in terms of accuracy, resolution or conversion rate, are considering increasingly mixed hardware and software A/D solutions tailored for specific application demands. In this context, this chapter presents a discrete low-cost A/D conversion solution based on pulse width modulation particularly suited for microcontrollers' integration with smart sensing devices.
- Industrial Internet of the ThingsPublication . Viegas, Vítor; Pereira, José Miguel Costa Dias