Desempenho de modelos analíticos de previsão da contribuição de materiais compósitos no reforço ao corte de vigas de betão armado

Na presente comunicação são apresentados alguns modelos analíticos para previsão da contribuição de materiais compósitos no reforço ao corte de vigas de betão armado recentemente introduzidos nos códigos de dimensionamento, sendo o seu desempenho aferido por comparação entre os valores estimados pelas formulações analíticas com os registados numa base de dados contendo informação referente a mais de 200 programas experimentais.Os autores manifestam os seus agradecimentos ao apoio prestado pela Fundação para a Ciência e Tecnologia (FCT) no projecto POCI/ECM/59033/2004. O primeiro autor agradece a bolsa UMINHO/POCI-59033/BI/05 concedida ao abrigo deste projecto

Novas perspectivas para o desenvolvimento de modelos de dimensionamento ao corte de vigas de betão armado reforçadas com FRP colado externamente

Com o presente artigo pretende-se apresentar uma base de dados (BD) contendo os registos relativos a mais de 250 vigas reforçadas ao corte com materiais poliméricos reforçados com fibras (FRP) e ensaiadas em diversos programas experimentais conduzidos por diferentes autores. O desempenho dos modelos de dimensionamento propostos pelo fib, ACI, e pelas Norma Italiana CNR-DT200 e Norma Australiana CIDAR é aferido comparando o comportamento observado experimentalmente com as previsões obtidas por via analítica. Tendo por base os resultados registados na BD, foi efectuado um estudo paramétrico com o objectivo de avaliar a influência no desempenho dos modelos de dimensionamento de diversos factores não explicitamente considerados nas formulações analíticas que os suportam. Os resultados são analisados, interpretados e apontadas as limitações encontradas nos modelos de dimensionamento em estud

Reliability analysis of shear strengthening EBR FRP models

This work presents a statistically oriented study aiming to assess the reliability of some of the most well known design models available for the prediction of the contribution of fiber reinforced polymer (FRP) systems applied according to the externally bonded reinforcing (EBR) technique for the shear strengthening of reinforced concrete (RC) beams. Relevant data was collected from experimental programs carried out in recent years in the context of the shear strengthening with FRP, and an extended database was obtained. Using this data, the performance of fib, ACI, Italian and Australian design guidelines was appraised by means of comparing the contribution of the FRP shear systems predicted by the analytical formulations with those registered experimentally. In general, the obtained results were not very promising, since a large scatter of the design safety factor was observed and, for some cases, the contribution of the FRP systems predicted by the design models was highly unconservative, which may be a serious concern as these formulations may be currently being used in design practice.The study reported in this paper forms a part of the research programme Cutinemo, supported by FCT, PTDC/ECM/73099/2006

Design models for shear strengthening of reinforced concrete beams with externally bonded FRP composites : a statistical vs reliability approach

Fundação para a Ciência e a Tecnologia (FCT) - POCTI/ECM/59033/200

A robust feature extraction for automatic speech recognition in noisy environments

This paper presents a method for extraction of speech robust features when the external noise is additive and has white noise characteristics. The process consists of a short time power normalisation which goal is to preserve as much as possible, the speech features against noise. The proposed normalisation will be optimal if the corrupted process has, as the noise process white noise characteristics. With optimal normalisation we can mean that the corrupting noise does not change at all the means of the observed vectors of the corrupted process. As most of the speech energy is contained in a relatively small frequency band being most of the band composed by noise or noise-like power, this normalisation process can still capture most of the noise distortions. For Signal to Noise Ratio greater than 5 dB the results show that for stationary white noise, the normalisation process where the noise characteristics are ignored at the test phase, outperforms the conventional Markov models composition where the noise is known. If the noise is known, a reasonable approximation of the inverted system can be easily obtained performing noise compensation still increasing the recogniser performance

Ejercicio físico y estilo de vida sedentario: consecuencias para la salud

Perhaps the greatest barriers for achieving major advances in public health in the twenty-first century result from the paralysis of the pandemic paradigm or from the widespread inability to envision alternative or new models of thought. Human movement represents a complex behavior that is influenced by personal motivation, health and mobility problems, genetic factors, and social and physical environments in which people live. These factors influence the propensity to engage in sedentary behaviors or in physical activity. However, the biological, social, and environmental pathways leading to sedentary behavior versus physical activity may be different. In addition, the health effects associated with sedentary behavior and physical activity may be the result of different biological mechanisms. Thus, our objective was to discuss the importance of physical exercise on health-related outcomes and the consequences of sedentary lifestyles. Research on sedentary behavior has been growing;however, the evidence for its determinants is relatively sparse. More studies are needed to obtain more conclusive results because it is fundamental to understand these complex relationships related to the practice and the acquisition of active and healthy lifestyles as opposed to a sedentary lifestyle.info:eu-repo/semantics/publishedVersio

Metallic-insulator phase transitions in the extended Harper model

In this work we investigate the transport properties of non-relativistic quantum particles on incommensurate multilayered structures with the thicknesses $w_n$ of the layers following an extended Harper model given by $w_n = w_0 |\cos(\pi a n^{\nu})|$. For the normal incidence case, which means an one-dimensional system, we obtained that for a specific range of energy, it is possible to see a metallic-insulator transition with the exponent $\nu$. A metallic phase is supported for $\nu<1$. We also obtained that for the specific value $\nu=1$ there is an alternation between metallic and insulator phases as we change the disorder strength $w_0$. When we integrate out all incidence angles, which means a two-dimensional system, the metallic-insulator transition can be seen for much larger range of energy compared to the normal incidence case

Production of curcumin from ferulic acid by an engineered Saccharomyces cerevisiae

II Congress in Health Sciences Research: Towards Innovation and Entrepreneurship - Trends in Biotechnology for Biomedical ApplicationsCurcumin is a secondary metabolite produced in the rhizome of Curcuma longa that represents the most active and studied naturally-derived curcuminoid product. Studies have confirmed its biological and therapeutic effects in several diseases being the anticancer activity the most documented. Since curcumin is synthetized in low amounts, its heterologous production could represent a rapid and easy method to obtain large amounts of this bioactive compound. Curcumin has already been produced in engineered Escherichia coli although with low yields. However, the curcumin biosynthetic pathway has never been engineered in Saccharomyces cerevisiae. As a eukaryotic organism, it presents unique advantages over E. coli that facilitate the expression of plant derived genes. This work aimed to design an artificial biosynthetic pathway for the production of curcumin by S. cerevisiae. The principal enzymes involved in the artificial pathway are: 4-coumarate-CoA ligase (4CL) and the type III polyketide synthases (PKSs). In C. longa there are two types of PKSs - diketide-CoA (DCS) and curcumin synthase (CURS) - that catalyse different reactions. Curcuminoid synthase (CUS) from Oryza sativa is also a PKS able of catalysing the one-pot synthesis of curcuminoids in E. coli. Herein, we intended to produce curcumin using ferulic acid as precursor. For that purpose, shuttle vectors with enzymes from different organisms were constructed and transformed in S. cerevisiae CENPK2-1C. The vectors carry 4CL from Arabidopsis thaliana or Lithospermum erythrorhizon, and DCS and CURS or CUS. DCS and CURS were codon-optimized for S. cerevisiae. In addition, CRISPRCas9 method was used to knockout a gene from S. cerevisiae that codifies ferulic acid decarboxylase that is responsible for the ferulic acid decarboxylation as a detoxification process. The engineered strains are currently being tested for curcumin production.info:eu-repo/semantics/publishedVersio

Automatic Vehicle Trajectory Extraction by Aerial Remote Sensing

Research in road users’ behaviour typically depends on detailed observational data availability, particularly if the interest is in driving behaviour modelling. Among this type of data, vehicle trajectories are an important source of information for traffic flow theory, driving behaviour modelling, innovation in traffic management and safety and environmental studies. Recent developments in sensing technologies and image processing algorithms reduced the resources (time and costs) required for detailed traffic data collection, promoting the feasibility of site-based and vehicle-based naturalistic driving observation. For testing the core models of a traffic microsimulation application for safety assessment, vehicle trajectories were collected by remote sensing on a typical Portuguese suburban motorway. Multiple short flights over a stretch of an urban motorway allowed for the collection of several partial vehicle trajectories. In this paper the technical details of each step of the methodology used is presented: image collection, image processing, vehicle identification and vehicle tracking. To collect the images, a high-resolution camera was mounted on an aircraft's gyroscopic platform. The camera was connected to a DGPS for extraction of the camera position and allowed the collection of high resolution images at a low frame rate of 2s. After generic image orthorrectification using the flight details and the terrain model, computer vision techniques were used for fine rectification: the scale-invariant feature transform algorithm was used for detection and description of image features, and the random sample consensus algorithm for feature matching. Vehicle detection was carried out by median-based background subtraction. After the computation of the detected foreground and the shadow detection using a spectral ratio technique, region segmentation was used to identify candidates for vehicle positions. Finally, vehicles were tracked using a k- shortest disjoints paths algorithm. This approach allows for the optimization of an entire set of trajectories against all possible position candidates using motion-based optimization. Besides the importance of a new trajectory dataset that allows the development of new behavioural models and the validation of existing ones, this paper also describes the application of state-of-the-art algorithms and methods that significantly minimize the resources needed for such data collection. Keywords: Vehicle trajectories extraction, Driver behaviour, Remote sensin

using network analysis to understand the position of Portugal in a global FDI network

Lima, F., Pinheiro, F. L., Silva, J. F., & Matos, P. (2020). Foreign direct investment: using network analysis to understand the position of Portugal in a global FDI network. In Bridging measurement challenges and analytical needs of external statistics: evolution or revolution?: Proceedings of the IFC Conference on external statistics, Lisbon, Portugal, 17-18 February 2020 (pp. 1-16). (IFC Bulletin; No. 52). Bank of International Settlements. https://www.bis.org/ifc/publ/ifcb52.htmUnderstanding the role of foreign direct investment (FDI) is of utmost importance in a world economy of increasingly interdependent economies. However, the lack of an unified data source of FDI covering a long time frame has posed serious challenges to its analysis. In this article we apply methods of network analysis to build a representation of the global FDI relationships. We show how the network representation of the global FDI can be used to identify patterns, identify preferential paths for investment, establish trends and describe the relations between countries over time. We present the results by using specific visualisation tools that graphically illustrate the interlinkages between the economies, and that can be a valuable instrument for the design and deployment of regulating instruments.publishersversionpublishe