Tipo e quantidade de atividade física e uso de dispositivos eletrónicos de estudantes do 7.◦ ao 12.◦ ano: caracterização e associação

ABSTRACT - Aim: To examine the association between self-reported physical activity and self-reported screen based time. Materials and methods: 969 high school students filled in a questionnaire on physical activity and screen based activities. Correlation analysis between time spent in moderate/vigorous physical activities and time spent in screen based activities were performed. Results: No association was found between physical activity and time spent watching TV, playing or using computers. A low correlation was found between time using mobile phones and time spent performing moderate physical activities (r = 0.09, p < 0.05), and vigorous physical activities (r = 0.13, p < 0.05). Conclusions: These findings suggest that screen time is not displacing physical activity.RESUMO - Objetivos: Explorar a associação entre o nível de atividade física e o uso de dispositivos eletrónicos. Materiais e métodos: Novecentos e sessenta e nove alunos do secundário preencheram um questionário sobre atividade física e uso de dispositivos eletrónicos. Foi realizada uma análise de correlação entre o tempo despendido em atividade física moderada e intensa e o uso de dispositivos eletrónicos. Resultados: Não há correlação entre a atividade física e ver televisão, jogar ou usar computadores. Há uma correlação baixa entre o uso de telemóveis e a atividade física moderada (r = 0,09, p < 0,05) e vigorosa (r = 0,13, p < 0,05). Conclusões: Estes resultados sugerem que o uso de dispositivos eletrónicos não interfere com a prática da atividade física.info:eu-repo/semantics/publishedVersio

Teletrabalho: Que oportunidade de trabalho para o cidadão incapacitado?

A natureza do trabalho, tal como até agora tem sido entendido, está a atravessar uma redefinição fundamental. O teletrabalho e o trabalho remoto efectuado em computador constituem duas das manifestações dessa redefinição. Um grupo que tem sido apontado como potencial beneficiário da adopção destas novas modalidades de trabalho é o constituído pelas pessoas que, por uma razão ou outra, estão relativamente «amarradas à casa», nomeadamente, as que possuem algum tipo de incapacidade.No entanto, o assunto levantaquestões de vária ordem. Designadamente, importa determinar qual a disponibilidade das empresas para adoptarem novas modalidades de trabalho, quais as actividades que elas estão dispostas a dar a executar a entidades externas e qual o modelo de trabalho mais adequado, nomeadamente, quando em causa estão trabalhadores com necessidades especiais. Por outro lado, é necessário determinar e analisar percepções, expectativas e ideias pré-concebidas, de modo a gerir, adequadamente, eventuais resistências e apresentar soluções passíveis de serem adoptadas e utilizadaseficazmente.Mais ainda, é fundamental averiguar até que ponto as oportunidades proporcionadas pelas tecnologias da informação e da comunicação significam uma vida mais completa e digna, ao nível moral, psicológico, intelectual e social para o cidadão portador de incapacidade. Este trabalho reporta os resultados de um estudo desenhado para responder a estas questões. Ele também permitiu descobrir quais as competências que os potenciais teletrabalhadores necessitam ter, possibilitando o progresso de acções de formação e o desenvolvimento de estratégias de inserção adaptadas ao teletrabalhador e às necessidades e expectativas das empresas

Electrical impedance tomography for damage detection and localization on carbon fibre reinforced polymer composites

Electrical impedance tomography (EIT) is being developed as promising non-intrusive technology for damage detection in conductive fibre reinforced polymers (FRP) composites. This work assessed EIT and one-step difference Gaussian-Newton algorithm to detect different damages in CFRP laminates, including through-thickness holes and impact damage of different severities. Two layup laminates were studied: quasi-isotropic [0/45/90/-45]s and unbalanced [0/0/45/90/-45]s. Each laminate configuration was subjected to three levels of impact energy.Through-thickness holes with diameters as small as 2 mm were detected. The LVI on unbalanced specimens created elongated shaped damages, which were observed through EIT and ultrasonic C-scan. Differently, the ultrasonic C-scan inspections revealed circular shaped damages on the centre of the quasi-isotropic specimens, while EIT could not reveal a well-defined damage shape Yet, the presence of damage was observed in the centre of the specimens by EIT. Although EIT overestimated the damaged area, it was highly sensitive to the imposed damages.The authors would like to acknowledge the support of the European Regional Development Fund [grant number NORTE-01-0145-FEDER-000015]; and of the European Space Agency [Network/Partnering Initiative Program - ESA Contract 4000123315]

Damage localization on CFRP composites by electrical impedance tomography

This work exploited the use of electrical impedance tomography (EIT) with one-step difference Gaussian-Newton (GN) algorithm to detect different types of damage on unidirectional carbon fibre/epoxy composite laminates. The major challenge concerning the implementation of EIT on composite materials has to do with their anisotropy. To assess this issue, this study was conducted on carbon fibre composites having different layup configurations with different degrees of anisotropy: a quasi-isotropic layup, to approximate as much as possible these layered materials to an isotropic material, and an unbalanced layup, with further degree of anisotropy. Damage detection in the highly anisotropic unbalanced laminates is a major challenge for EIT technique, which has not been assessed before in the literature. Severe damage, in the form of through-thickness holes, was created in the laminates with different diameters and at two locations of the specimen to evaluate the sensitivity of this technique to damage size and its capacity to detect multiple damages. EIT showed progressive decrease of electrical conductivity as the diameter of through-thickness holes increased. Impact damages of different severities were also created. The EIT technique was able to distinguish different damage shapes in the laminates with different anisotropy. EIT identified elongated shaped damages, produced by impact events of different impact energies, on unbalanced laminates. However, the EIT images overestimate the damaged area, as compared to non-destructive ultrasonic inspections. The EIT images of the quasi-isotropic laminates revealed damage in the central area of the specimens, but a well-defined damage shape could not be distinguished.ANI, H2020, Contrato NORTE-01-0145-FEDER-00001

Exploring the Effect of Hierarchical Porosity in BEA Zeolite in Friedel-Crafts Acylation of Furan and Benzofuran

Hierarchical BEA zeolite was prepared through desilication or desilication followed by acid treatment. The catalytic performance of BEA zeolite samples was evaluated using Friedel-Crafts acylations with two substrates of different molecular sizes, furan (5.7 Å) and benzofuran (6.9 Å), in the presence of acetic anhydride as acylating agent. The application of the simplified Langmuir-Hinshelwood kinetic model showed that the size of the substrate leads to different catalytic activities, with improved rate constant and turnover frequency (TOF) solely in the presence of benzofuran for both desilicated and further acid treated samples. The mesopores developed during the zeolite treatments have an important role as transportation channels by reducing diffusion limitations. The application of Quantitative Structure–Property Relationships (QSPR) allowed the finding of the most relevant properties of the zeolite and substrate with impact on the catalytic parameters.publishe

Collapsing Perfect Fluid in Higher Dimensional Spherical Spacetimes

The general metric for N-dimensional spherically symmetric and conformally flat spacetimes is given, and all the homogeneous and isotropic solutions for a perfect fluid with the equation of state $p = \alpha \rho$ are found. These solutions are then used to model the gravitational collapse of a compact ball. It is found that when the collapse has continuous self-similarity, the formation of black holes always starts with zero mass, and when the collapse has no such a symmetry, the formation of black holes always starts with a mass gap.Comment: Class. Quantum Grav. 17 (2000) 2589-259

Procedures of user-centered usability assessment for digital solutions: scoping review of reviews reporting on digital solutions relevant for older adults

The assessment of usability is a complex process that involves several steps and procedures. It is important to standardize the evaluation and reporting of usability procedures across studies to guide researchers, facilitate comparisons across studies, and promote high-quality usability studies. The first step to standardizing is to have an overview of how usability study procedures are reported across the literature.publishe

Experts evaluation of usability for digital solutions directed at older adults: a scoping review of reviews

Background: it is important to standardize the evaluation and reporting procedures across usability studies to guide researchers, facilitate comparisons, and promote high-quality studies. A first step to standardizing is to have an overview of how experts-based usability evaluation studies are reported across the literature. Objectives: to describe and synthesize the procedures of usability evaluation by experts that are being reported to conduct inspection usability assessments of digital solutions relevant for older adults. Methods: a scoping review of reviews was performed using a five-stage methodology to identify and describe relevant literature published between 2009 and 2020 as follows: i) identification of the research question; ii) identification of relevant studies; iii) select studies for review; iv) charting of data from selected literature; and v) collation, summary, and report of results. The research was conducted on five electronic databases: PubMed, ACM Digital Library, IEEE, Scopus, and Web of Science. The articles that met the inclusion criteria were identified, and data extracted for further analysis, including evaluators, current usability inspection methods, and instruments to support usability inspection methods. Results: a total of 3958 articles were identified. After a detailed screening, 12 reviews matched the eligibility criteria. Conclusion: overall, we found a variety of unstandardized procedures and a lack of detail on some important aspects of the assessment, including a thorough description of the evaluators and of the instruments used to facilitate the inspection evaluation such as heuristics checklists. These findings suggest the need for a consensus framework on the experts’ assessment of usability that informs researchers and allows standardization of procedures.in publicatio

Higher pain intensity, depression, and being 75 Years or Older are associated with lower Levels of self-reported physical activity in older adults with pain attending primary care

Objective: This study investigated whether pain characteristics (intensity, frequency, duration and number of pain sites), depression, age, sex and comorbidities are associated with lower levels of selfreported physical activity in older adults with pain at the primary healthcare setting.Methods: A total of 504 participants aged 60 years of age and over were assessed for: socio-demographics, comorbidities, pain, depression, and physical activity. Associations between these variables were investigated using ordinal logistic regression.Results: Reporting severe pain or worst imaginable pain, being older (≥ 75 years), and feeling depressed were significantly associated with lower physical activity in the univariate (OR = 2.33, 2.93, 2.31, and 2.23, respectively) and multivariate models (Adj OR = 2.21, 2.47, 2.49, and 1.97, respectively).Conclusions: Interventions aiming to increase physical activity for older adults in primary care should consider the needs of those reporting higher pain intensity, feeling depressed and who are 75 years or older

Efeito da solução desinfetante de iodo a 2% sobre a adesão à dentina

INTRODUCTION: Disinfection of dentin surfaces is desirable so long as it does not interfere with subsequent bonding of adhesive resins. OBJECTIVE: To test the null hypothesis that bond strengths to dentin are not affected by previous application of an iodine disinfecting solution. MATERIALS AND METHODS: Twenty-four extracted non-carious molars were selected. Occlusal enamel was removed producing a flat dentin substrate. Test teeth were all treated with 2% Iodine disclosing/disinfecting solution (I2DDS) for 20 sec and rinsed for 20 sec followed by the application of self- or total- etching bonding systems, generating five adhesive groups (n=3): Single Bond; ; Prime & Bond NT; Clearfil SE Bond; Opti-Bond Plus. The control groups (n=3 per adhesive) had no disclosing/disinfectant application prior to adhesive application. A 4-mm thick resin restoration was built up on each tooth for microtensile testing. Statistical analyses between experimental and control groups were performed by student's t-test (alpha= 0.05). RESULTS: In general, experimental groups (previously treated with I2DDS) showed significantly lower bond strength values when compared with their respective controls (p;0.05). CONCLUSION: Acetone-base adhesive systems seem not to be affected by the application of I2DDS prior to etching and bonding procedures.INTRODUÇÃO: A desinfecção das superfícies de dentina é desejada desde que não haja interferência na adesão dos agentes adesivos. OBJETIVO: Testar a hipótese nula de que a resistência adesiva não é afetada pela aplicação prévia de uma solução desinfetante de iodo. MATERIAL AND MÉTODO: Vinte e quatro molares hígidos foram selecionados. O esmalte oclusal destes dentes foi removido, e sobre as superfícies planas de dentina expostas foi aplicada da solução desinfetante de Iodo a 2% (I2DDS), que permaneceu sobre a superfície por 20 s e foi lavada por 20 s com água deionizada. Sobre as superfícies desinfetadas foram aplicados um dos seguintes sistemas adesivos (n=3): Single Bond; Prime & Bond NT; Clearfil SE Bond; Opti-Bond Plus. Os grupos controle (n=3) não tiveram a supeficie de dentina tratada com I2DDS antes dos precedimentos adesivos. Em todos os grupos, após hibridização da dentina, foi construída uma "restauração" de resina composta com cerca de 4 mm de espessura. Após 7 dias de armazenagem em água destilada, os dentes foram secionados de modo a originarem espécimes a serem submetidos ao teste de microtração (palitos). Análise estatística para comparação dos dados foi realizada pelo teste t de student (alfa=0,05). RESULTADOS: De forma geral, os grupos experimentais (tratados com I2DDS) apresentraram resistência adesiva significativamente menor do que os respectivos grupos controle (p;0.05). Assim, a hipótese nula deve ser rejeitada para os adesivos a base de etanol e/ou a base de água, mas aceita para o adesivo a base de acetona. CONCLUSÃO: O uso da solução experimental de iodo previamente à realização dos procedimentos adesivos afetou a efetividade da união à dentina apenas quando do emprego de sistemas adesivos a base de etanol e/ou água