Browsing by Author "Silva, Rui"
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- Academic Entrepreneurship Ecosystems: Systematic Literature Review and Future Research DirectionsPublication . Correia, Maria Patrocínia; Marques, Carla Susana; Silva, Rui; Ramadani, VelandResearch on the entrepreneurship ecosystem, based on different data and scales, limits the acceptance of a single definition. This conceptual limitation and the still recent research and higher education institutions have come to be seen as ecosystems associated with entrepreneurship. The aim of this study is to contribute to the field of knowledge, identify current and emerging thematic areas and trends and reveal the scientific roots of research on entrepreneurial ecosystems and their relationship with higher education institutions. A bibliometric analysis was developed to analyse a final sample of 110 articles published between 2011 and 2022. In order to develop the analysis, Bibliometrix R-Tool was used and the metadata of two databases (Web of Science and Scopus) was retrieved and merged. The software creates a reference co-citation's map, which allowed emphasize the state of the art and indicate three thematic clusters: (i) the importance of the higher education context for the entrepreneurial ecosystem, (ii) the evolution and challenges of entrepreneurship education and (iii) academic entrepreneurship ecosystems. The paper concludes by suggesting future research focused on the importance of building an integrated approach to entrepreneurial ecosystems and higher education institutions on a context regional scale.
- An experimental analysis on the thermal performance of rammed earth wallsPublication . Luso, Eduarda; Cabello, Isabelle; Silva, Rui; Briga-Sá, AnaEarth has been used as a building material since the beginning of civilizations and its utilization was widespread to most regions of the world, promoted by the high availability, easy access, and low cost of the material. As result of the generalised use of raw earth as building material, many earthen building techniques were developed through time, where adobe masonry, rammed earth and wattle-and-daub are among the most important. Currently, it is estimated that one quarter of the world's population lives in buildings made of earth. However, during the last century, earthen materials fell into disuse in several developed countries with the popularization of concrete, steel and fire bricks. Nevertheless, earthen architecture has been receiving increasing attention in the last few decades, driven by its green building potential and by other features of earthen materials, which includes, among others, unique aesthetics and hygrothermal regulation capacity. Several studies have been developed to characterize earthen solutions concerning physical and mechanical properties. However, regarding the thermal behaviour, it is known that the thermal conductivity of rammed earth is a parameter that depends on the characteristics of the soil (particle size distribution, mineralogy, etc.) and moisture content. Thus, given the soils variability, it becomes clear that further investigation should be addressed to characterize the thermal performance of rammed earth solutions, contributing to define more accurate thermal conductivity values for the design of rammed earth buildings. On this regard, this paper presents an experimental study that aims to characterize the thermal behaviour of rammed earth built with different soils and with different thicknesses. A continuous measurement allowed to obtain heat fluxes, inner surface temperatures and the thermal transmission coefficient of the tested rammed earth walls solutions. Values of 0.72 W/mºC and 1.17 W/mºC were obtained for the thermal conductivity, showing the thermal behaviour variability depending on the soil composition. It was also confirmed that thickness significantly influences the earthen solution thermal behaviour, being verified that the thermal transmission coefficient of a 50 cm thick wall is about 30% lower than the one verified for the wall with 35 cm, built with the same soil.
- Analysis of the physiological response in junior tennis players during short-term recovery: understanding the magnitude of recovery until and after the 25 seconds rulePublication . Morais, J.E.; Bragada, José A.; Silva, Rui; Nevill, Alan M.; Nakamura, Fabio Y.; Marinho, D.A.Literature lacks evidence about the physiological recovery of tennis players between points. This study aimed to: (i) verify the heart rate (HR) and oxygen uptake (V̇O2) recovery variance in young tennis players from the end of a tennis drill until the 25-s mark and onwards (65-s limit), performed at several intensities, and (ii) test the curve fitting that better characterizes the players’ HR and V̇O2 recovery, from the end of the drill until the 65-s mark. The sample was composed of 13 male tennis players (age: 16.80 ± 1.61 years) recruited from a National Tennis Association. Players were instructed to perform a drill test (“two-line drill wide mode”) based on an intensity increment protocol. Three levels of intensity were used based on the reserve HR and V̇O2. A significance level effect was observed on the HRreserve and V̇O2reserve (P <.001). At all three levels of intensity, the first 25 s were enough to significantly (P <.001) recover the HRreserve and V̇O2reserve. The same significance trend (P <.001) was maintained until the 65 s but with a lower magnitude over time. Overall, the HR and V̇O2 curve fitting indicated a cubic relationship at the three levels of intensity (except the V̇O2 at the first level). Considering the specific test performed, players significantly elicited their physiological profile for every additional 10 s (after the 25-s rule) in the three levels of intensity performed. Despite this being a drill test and not a competitive point, coaches, players, and tennis organizations should be aware of these findings
- Are Portuguese Higher Education Students Motivated to Study English as a Second/Foreign Language?Publication . Bessa, Luciana Cabral B.; Silva, Elisabete Mendes; Meirinhos, Galvão; Silva, RuiBeing motivated is fundamental for any individual to achieve personal and professional success. In the context of learning in Higher Education, Motivation is crucial for achieving this success. Understanding the motivational state of students is essential for higher education managers and teachers. Understanding students’ Amotivation, intrinsic and extrinsic motivation can provide vital information to initiate changes in teaching and learning. In this sense, measuring Amotivation, Intrinsic Motivation, and Extrinsic Motivation allows for understanding the general state of students’ Motivation. This study aims to analyze the Motivation of 145 Portuguese Higher Education Students (70 Male and 75 Female) aged between 17 and 47 years old who studied the second/foreign language (English) in Portugal during the Academic Year of 2020/2021. We used the Academic Motivation Scale to measure Motivation to study English. The results show that students are not demotivated. The Motivation that prevails in the results is Intrinsic Motivation, and Extrinsic Motivation was insignificant. This study’s results contribute to the literature on Motivation to study Second Language, especially concerning the need to understand why students are only intrinsically motivated. Are the lessons, the teaching methodologies, the techniques and the contents not able to motivate them?
- The developmental trajectory of motor competence of children that lived the COVID-19 confinement period: a four-year follow-up study in Portuguese childrenPublication . Carballo-Fazanes, Aida; Rodrigues, Luis Paulo; Silva, Rui; Lopes, Vitor P.; Abelairas-Gómez, CristianChildren’s motor competence (MC) was negatively affected by the COVID-19 pandemic; however, possible chronic effects have not been studied. Therefore, the aim of this study was to examine the possible impact of the forced lack of physical activity (PA) during the COVID-19 lockdown on children’s MC two years later. The motor competence of sixty-seven healthy children (7.4–12.2 years old) was assessed using the Motor Competence Assessment (MCA). All participants completed the MCA tests at two different moments (before and after the COVID-19 lockdown), four years apart. The mean values after the COVID-19 lockdown for all participants on the subscales and on the Total MCA are lower, but no significant changes were found when controlling for gender and age (p > 0.05 in all analyses). However, a significant decrease was found in the Locomotor subscale in boys (p = 0.003). After dividing the participants into three age groups, the youngest also suffered a decrease in the Locomotor subscale (p < 0.001) and their Total MCA (p = 0.04). In addition, those participants who had a higher MC at baseline decreased their scores for the Locomotor (p < 0.001) and Manipulative (p < 0.001) subscales, and for the Total MCA (p < 0.001). In conclusion, the younger children and the more motor proficient did not fully recover from the negative effects of the pandemic lockdown after two years.