Universidade Federal de Santa Maria

About: Universidade Federal de Santa Maria is a education organization based out in Santa Maria, Brazil. It is known for research contribution in the topics: Population & Context (language use). The organization has 21178 authors who have published 35632 publications receiving 371665 citations.

Portuguese-language version of the Epworth sleepiness scale: validation for use in Brazil

Abstract: Objective: The aim of this study was to develop a Portuguese-language version of the Epworth sleepiness scale (ESS) for use in Brazil. Methods: The steps involved in creating the ESS in Brazilian Portuguese (ESS-BR) were as follows: translation; back-translation; comparison (by a committee) between the translation and the back-translation; and testing in bilingual individuals. The ESS-BR was applied to a group of patients who were submitted to overnight polysomnography in order to identify obstructive sleep apnea-hypopnea syndrome (OSAHS), insomnia and primary snoring. A control group was composed of subjects with a history of normal sleep habits, without reported snoring. Results: A total of 114 patients and 21 controls were included. The 8-item scores of the ESS-BR had an overall reliability coefficient of 0.83. The study group was composed of 59 patients with OSAHS, 34 patients with primary snoring and 21 patients with insomnia. One-way ANOVA demonstrated significant differences in ESS-BR scores among the four diagnostic groups (p 0.05). The ESS-BR scores were significantly higher for OSAHS patients and for primary snorers than for controls (p < 0.05). In addition, the scores for OSAHS patients were significantly higher than were those for primary snorers (p < 0.05). Conclusions: The results of the present study demonstrate that the ESS-BR is a valid and reliable instrument for the assessment of daytime sleepiness, equivalent to its original version when applied to individuals who speak Brazilian Portuguese.

A Maximum Power Point Tracking System With Parallel Connection for PV Stand-Alone Applications

Abstract: This paper presents the analysis, design, and implementation of a parallel connected maximum power point tracking (MPPT) system for stand-alone photovoltaic power generation. The parallel connection of the MPPT system reduces the negative influence of power converter losses in the overall efficiency because only a part of the generated power is processed by the MPPT system. Furthermore, all control algorithms used in the classical series-connected MPPT can be applied to the parallel system. A simple bidirectional dc-dc power converter is proposed for the MPPT implementation and presents the functions of battery charger and step-up converter. The operation characteristics of the proposed circuit are analyzed with the implementation of a prototype in a practical application.