Browsing by Author "Ferreira, M."
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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.
- How to survive earthquakes: the example of NorciaPublication . Lopes, M.; Sá, F. M.; Ferreira, M.; Oliveira, Cristina
- Long term experience in Autonomous Stations and production quality controlPublication . Lopes, L.; Alves, A.B.; Assis, P.; Blanco, A.; Carolino, N.; Cerda, M.A.; Conceição, R.; Cunha, O.; Dobrigkeit, C.; Ferreira, M.; Fonte, P.; de Almeida, L.; Luz, R.; Martins, V.B.; Mendes, L.; Nogueira, J.C.; Pereira, A.; Pimenta, M.; Sarmento, R.; de Souza, V.; Tomé, B.
- MARTA: a high-energy cosmic-ray detector concept for high-accuracy muon measurementPublication . Abreu, P. et al. (45 authors); Andringa, S.; Assis, P.; Blanco, A.; Brogueira, P; Carolino, N.; Cazon, L.; Conceição, R.; Cunha, O; Diogo, F.; Espadanal, J.; Ferreira, M.; Ferreira, P.; Fonte, P.; Gonçalves, P.; Lopes, L.; Mendes, L.; Pereira, A.; Pimenta, M.; Sarmento, R.; Tomé, B.; Wolters, H.A new concept for the direct measurement of muons in air showers is presented. The concept is based on resistive plate chambers (RPCs), which can directly measure muons with very good space and time resolution. The muon detector is shielded by placing it under another detector able to absorb and measure the electromagnetic component of the showers such as a water-Cherenkov detector, commonly used in air shower arrays. The combination of the two detectors in a single, compact detector unit provides a unique measurement that opens rich possibilities in the study of air showers.
- Outdoor Field Experience with Autonomous RPC Based StationsPublication . Lopes, L.; Assis, P.; Blanco, A.; Carolino, N.; Cerda, M.A.; Conceição, R.; Cunha, O.; Ferreira, M.; Fonte, P.; Luz, R.; Mendes, L.; Pereira, A.; Pimenta, M.; Sarmento, R.; Tomé, B.In the last two decades Resistive Plate Chambers were employed in the Cosmic Ray Experiments COVER-PLASTEX and ARGO/YBJ. In both experiments the detectors were housed indoors, likely owing to gas distribution requirements and the need to control environment variables that directly affect RPCs operational stability. But in experiments where Extended Air Shower (EAS) sampling is necessary, large area arrays composed by dispersed stations are deployed, rendering this kind of approach impossible. In this situation, it would be mandatory to have detectors that could be deployed in small standalone stations, with very rare opportunities for maintenance, and with good resilience to environmental conditions. Aiming to meet these requirements, we started some years ago the development of RPCs for Autonomous Stations. The results from indoor tests and measurements were very promising, both concerning performance and stability under very low gas flow rate, which is the main requirement for Autonomous Stations. In this work we update the indoor results and show the first ones concerning outdoor stable operation. In particular, a dynamic adjustment of the high voltage is applied to keep gas gain constant.
- The cancer registry as an ally in monitoring treatment effectivenessPublication . Costa, F. A.; Ramos, C.; Murteira, R.; Almodovar, T.; Passos-Coelho, J. L.; Carvalho, M. I.; Costa, L.; Brito, M. J.; Ramos, S.; Ferreira, M.; Miranda, A. C.OBJECTIVE: To evaluate if the cancer registry database can be used to monitor treatment effectiveness using nivolumab treatment of non-small cell lung cancer (NSCLC) as an example. METHOD: An observational inception cohort was used, where all registered cases of NSCLC with authorisation to initiate treatment with nivolumab were monitored retrospectively to evaluate disease characteristics and response to prior treatments. Current exposure to nivolumab was prospectively characterised and treatment outcomes classified based on the clinical information registered in the patient medical record. The main outcome measure used to assess treatment effectiveness was overall survival (OS). Secondary outcomes considered were progression free survival (PFS) as a measure of effectiveness and occurrence of Adverse Drug Reaction (ADRs) as a measure of safety. Data were analysed using SPSS, version 24. RESULTS: A total of 115 patients received treatment with nivolumab for NSCLC, between November 1st 2015 and July 31st 2016, and were registered in the database. The majority were non-squamous type (n=107). The median OS was 11.4 months {CI95%: 11.1-11.7}, with a 1-year survival of 44%, in line with clinical trial data. Median PFS was 5.4 months {CI95%: 2.8-7.9}. Treatment was discontinued in 82 cases, most frequently due to disease progression. There were 38 cases of ADRs documented in the patient medical chart, 21 of which led to treatment discontinuation. CONCLUSION: The analysed data suggest that the cancer registry is a powerful tool to monitor treatment effectiveness, although considerable investment is needed to improve the medical culture of recording treatment exposure, particularly documentation of ADRs.