Browsing by Author "Santos, M."
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- A 1.1 µA voltage reference circuit with high PSRR and temperature compensationPublication . Pereira, M. Silva; Costa, João E. N.; Santos, M.; Vaz, J. CaldinhasThis paper presents a low-power and a low output voltage CMOS Bandgap Reference Generator topology with high PSRR and a novel temperature curvature compensation method. The proposed design was implemented in a standard 0.13 μm CMOS process. The main circuit is based in an opamp based β-multiplier bandgap circuit with resistive division. The compensation method cancels out up to 2nd order non-linear terms of the BJT voltage by using the MOSFET leakage current effect. The performance of the circuit was verified by post-layout simulations. Simulated results have shown temperature coefficients as low as -4.4 ppm/°C over a temperature range of 140°C (-40°C to 100°C). In addition the circuit demonstrated a PSSR of -100 dB at low frequencies and -73 dB at 1 MHz. The current consumption is 1.1 μA at 27°C.
- Mouthguard and orofacial traumatism in young roller hockey practicersPublication . Lopes, Luísa; Santos, M.Objective: This study aimed to investigate the prevalence of mouthguard used and orofacial trauma in a roller hockey population and verify the several associated factors. Materials and Methods: An observational cross-sectional study based on clinical observation and questionnaire application to the athletes under search. The sample consisted of 117 roller hockey athletes between 13 and 19 years old, in Portugal, in several clubs which were, Sporting Clube de Portugal, Sport Lisboa e Benfica, Clube Desportivo de Pa#xE7;o de Arcos and Parede Futebol Clube. Results: The prevalence of mouthguard used was 16.2%, and 56.2% of them used Type II, and 47.4% Type III. The prevalence of orofacial trauma was 38.5%, in which 71.1% of these dental injuries involved the upper incisors, which were the most affected teeth, both the deciduous and definitive dentition. At the time of injury, only four athletes wore mouthguards, which 1 type I, 2 of type II and 1 of model III. Conclusion: Roller hockey is a sport in which the prevalence of mouthguard use is low, and that of orofacial trauma is high. Thus, the mouthguard is a device that should be more used by athletes, since it is useful in preventing these injuries.
- Projeto Juventude em Movimento: a relação entre o bullying, a vinculação e as condutas antissociaisPublication . Almeida, I.; Castela, R.; Costa, S.; Domingues, H.; Fernandes, B.; Ferreira, J.; Matias, S.; Morgado, R.; Romão, A.; Santos, F.; Santos, M.; Soeiro, C.