Assessment of the effectiveness of prestressed NSM CFRP laminates for the flexural strengthening of RC beams

The flexural behavior of RC beams strengthened with prestressed near-surface-mounted (NSM) carbon-fiber-reinforced-polymer (CFRP) laminate was investigated in this paper. For this purpose, four RC beams were tested under monotonic four-point loading. One beam was kept un-strengthened, as a control beam, and another one was strengthened with a non-prestressed NSM CFRP laminate. The remaining beams were strengthened with NSM CFRP laminates prestressed at 20% and 40% of its ultimate tensile strength. The prestressed NSM CFRP laminate technique provided a significant increment of the load carrying capacity for deflection levels corresponding to serviceability and ultimate limit states. A numerical strategy was also employed to simulate the flexural behavior of the tested RC beams. The experimental and numerical researches are described and the relevant results are presented and discussed.Fundação para a Ciência e a Tecnologia (FCT

Evaluation of the performance of full-scale RC beams prestressed with NSM-CFRP laminates

Carbon Fibre Reinforced Polymers (CFRP) applied according to the Near Surface Mounted (NSM) technique are known as capable of increasing the ultimate flexural resistance of Reinforced Concrete (RC) elements, but for Serviceability Limit States (SLS) the load increment it provides is, in general, relatively limited. Recently, researchers are giving attention towards the possibility of applying prestressed NSM-CFRPs to increase significantly the load carrying capacity of RC elements at SLS. As it is common knowledge, introducing prestress in a RC element produces an initial stress distribution, whose primary effect is, in the case of RC beams, the development of an initial deflection, typically in the opposite direction of loading. This initial stress field is the key factor that triggers most of the benefits of this technology, such as the delay in crack initiation and in steel yielding initiation. In this paper, the results of an experimental program consisting of a series of full-scale RC beams flexurally strengthened with NSM prestressed CFRP laminates up to four different levels (20%, 30%, 40% and 50%) will be presented. The experimental program is described and the main results are presented and discussed.Fundação para a Ciência e a Tecnologia (FCT

Influence of prestress level on NSM CFRP laminates for the flexural strengthening of RC beams

This study presents an experimental program to evaluate the influence of the prestressing technique on the flexural behavior of reinforced-concrete (RC) beams strengthened with near-surface-mounted (NSM) carbon-fiber-reinforced-polymer (CFRP) laminates. The experimental program was organized to highlight the benefits of this technique for flexural strengthening of RC beams with low reinforcement ratio, susceptible of not respecting serviceability-limit-state (SLS) conditions, namely the deflection limit. For this purpose, five RC beams were fabricated to be tested under monotonic four-point loading. One beam was kept unstrengthened as a control beam, and another one was strengthened with a non-prestressed NSM CFRP laminate. The remaining beams were reinforced with a NSM CFRP laminate prestressed at 20%, 30% and 40% of its nominal tensile strength. Based on the results, applying the prestress force provided an increase of load carrying capacity corresponding to the concrete cracking and steel yielding initiations compared to the non-prestressed strengthened beam. Moreover, the influence of prestress level on the prevailing failure mode of the tested beams was assessed, and the relevant results are presented and discussed. An advanced numerical strategy was also developed to simulate the tested beams, which was demonstrated capable of being used for the design of this type of structures.Fundação para a Ciência e a Tecnologia (FCT

Revisão do Sistema de Gestão da Qualidade: O Caso da CERCIG - Guarda

A Educação é um direito fundamental de todos, em geral, e da criança com necessidades educativas especiais, em particular, como processo de reduzir as diferenças de aprendizagem através de programas educacionais, que devem ser implementados tendo em conta a diversidade de características, de interesses e de habilidades das mesmas, desenvolvido por Instituições Particulares de Solidariedade Social (IPSS), como parceiras privilegiadas do Estado, que consolidam estratégias de qualidade e de responsabilidade social. Este relatório de estágio profissionalizante apresenta uma proposta de revisão do Sistema de Gestão da Qualidade, que se baseia na Norma NP EN ISO 9001: 2015 (IPQ, 2015a), aplicada à “CERCIG – Cooperativa de Educação e Reabilitação de Crianças Inadaptadas Guarda, C.R.L.” que é uma IPSS e que tem como objetivo garantir que a criança com necessidades educativas especiais tem acesso a serviços de educação e formação, com qualidade, e adequados à satisfação das suas competências e conhecimentos num quadro de expectativas e bem-estar. Sem dúvida que, o resultado do relatório de estágio profissionalizante garante que a criança, com necessidades educacionais especiais, deve ter acesso à Escola, acompanhada de uma pedagogia centrada no seu processo de inclusão e integração em Sociedade. Neste contexto, este relatório caracteriza o papel das IPSS, em geral, e da CERCIG, em particular. Enquanto parceiras das novas estratégias de educação e formação, em substituição das anteriores estratégias assentes nos paradigmas da diferenciação, viabilizadas com sistemas de gestão de qualidade que garantem a sua sustentabilidade futura

Thermo mechanic response of a ceramic material coated with gold

The present report has as the main objective to obtain, via the experimental process, the thermal response of a ceramic material coated with gold, when subjected to a variation of temperature. Under this context, the main information that it is important to be obtained consists in the calculation of the specific deformation, ε of the composite material (ceramic substrate coated with a gold top layer) that it is generated due to a temperature variation of about 100ºC. This information is of extreme importance because it imposes the adoption of specific techniques to be implemented in civil construction. It must be enhanced that the experimental activity also considered the study of the chemical composition and the morphology of the materials that were supplied by the manufacturer. In fact, this is essential information, since its knowledge helps to correlate and to interpret the thermo-mechanics response

Temperature responsiveness of gilthead sea bream bone; an in vitro and in vivo approach

This study aimed to characterize the molecules involved in osteogenesis in seabream and establish using in vitro/in vivo approaches the responsiveness of selected key genes to temperature. The impact of a temperature drop from 23 to 13 degrees C was evaluated in juvenile fish thermally imprinted during embryogenesis. Both, in vitro/in vivo, Fib1a, appeared important in the first stages of bone formation, and Col1A1, ON and OP, in regulating matrix production and mineralization. OCN mRNA levels were up-regulated in the final larval stages when mineralization was more intense. Moreover, temperature-dependent differential gene expression was observed, with lower transcript levels in the larvae at 18 degrees C relative to those at 22 degrees C, suggesting bone formation was enhanced in the latter group. Results revealed that thermal imprinting affected the long-term regulation of osteogenesis. Specifically, juveniles under the low and low-to-high-temperature regimes had reduced levels of OCN when challenged, indicative of impaired bone development. In contrast, gene expression in fish from the high and high-to-low-temperature treatments was unchanged, suggesting imprinting may have a protective effect. Overall, the present study revealed that thermal imprinting modulates bone development in seabream larvae, and demonstrated the utility of the in vitro MSC culture as a reliable tool to investigate fish osteogenesis."Ministerio de Economia y Competitividad" (MINECO) [BES-2015-074654]; Portuguese Science Foundation (FCT) [SFRH/BPD/111512/2015, SFRH/BD/81625/2011]; MINECO, Spain [AGL2010-17324, AGL2014-57974-R]; "Generalitat de Catalunya" (XRAq); Generalitat de Catalunya [2014SGR-01371]; FCT, Portugal [CCMAR/Multi/04326/2013]; European Union [LIFECYCLE EU-FP7 222719]info:eu-repo/semantics/publishedVersio

An embedded crack model for the simulation of the complex interactions in fibre reinforced concrete

There are several benefits of introducing steel fibres in reinforced concrete. They can improve the structural ductility, reduce the permeability, and provide more resistance to cracking caused by loading and shrinkage. Steel fibres are mainly activated when they are crossed by active cracks in what is known by the bridging effect. They are mostly inactive otherwise. With the progress of damage, the fibres can be pulled out or fail, in which case the bond with the cementitious matrix is a critical factor for accurate simulations. Although existing models that are able to simulate fibres as discrete elements can achieve realistic predictions, difficulties are found in the generation of complex meshes with numerous randomly-oriented fibres, namely due to the requirement of excessive degrees of freedom and long computational times. The formulation herein proposed, embeds both discrete fibres and cracks within the finite elements, while accounting for the main features of the fibre behaviour, including the main effects such as the bond between fibre and cementitious material and snubbing. It should be highlighted that the fibre behaviour is modelled without the need for additional degrees of freedom. An advanced constitutive behaviour law is implemented that accounts for the changes depending on the inclination angle of the fibre relative to the crack and its embedment length. For fracture simulation, the model uses the Discrete Strong Discontinuous Approach (DSDA), where the jumps related to the opening of the cracks are transmitted to the parent element as a rigid body motion. Several numerical tests are used to assess the performance of the numerical technique, which include comparison with other formulations and experimental data

Photovoltaic solar energy. A pedagogic approach

The present work reports on a simple pedagogic exploration of a photovoltaic solar kit which aims to demonstrate the operation of a mobile orientable photovoltaic solar energy collection system employing a robot built with Lego parts

Can Mediterranean terroirs withstand climate change ? Case studies at the Alentejo portuguese winegrowing region

XII Congreso Internacional TerroirClimate change introduced new challenges to vinegrowers in the Mediterranean areas such as the hot and dry winegrowing region of Alentejo, south Portugal. Warmer and drier conditions are harmful for grape yield and berry quality attributes and for vine’s longevity, mainly when optimal thresholds are exceeded. Therefore winegrowers are forced to move from rainfed to irrigated production systems making Alentejo’ wine production strongly based on available water resources for irrigation. This work aims to review and discuss ecophysiological and agronomical data obtained in irrigation trials set up at different terroirs of Alentejo. In the last four decades, classical bioclimatic temperature-based indices showed a significantly positive trend, while the dryness index present a negative trend over time. Furthermore, ecophysiological data collected in deficit irrigation experiments are reviewed and discussed, focusing on the effects of drought and heat stress on vigour, yield and berry composition. Emphasis is given on the indirect effects of leaf senescence on cluster exposure and consequences on berry temperature and composition. In order to promote the sustainability and quality of wine production in these hot and dry terroirs short- to longterm adaptation measures are suggested. The limitations and risks of using deficit irrigation during heat waves are also underlinedinfo:eu-repo/semantics/publishedVersio

Evaluation Of Osteoporosis Using Ultrasound

We have developed an equipment using ultrasound transducers to help in the diagnosis of osteoporosis. The equipment consists of an X-Y axes displacement system controlled by a microcomputer and uses two ultrasound transducers in opposite sides to inspect the calcaneus region of the patient. We have used two pairs of transducers with 500 kHz and 1 MHz central frequencies. Each pair of transducers was fixed in the X-Y displacement system submerged in a small water tank with a support for the foot of the patient. The transmitter was excited with pulses of 400-600 kHz or 800-1200 kHz and the ultrasound waves propagating through the bone in the calcaneus region are received by the opposite transducer, amplified and acquired in a digital oscilloscope. The data are transferred to the microcomputer and the ultrasound attenuation and the ultrasound transmission velocity are determined. The system was tested in patients, selected from a group that had already been diagnosed using a DEXA equipment. The results showed that there is a decrease in the ultrasound transmission velocity and the ultrasound attenuation in osteoporotic patients when compared to healthy patients of the same sex and age group. The conclusion is that ultrasound attenuation and the transmission velocity in the calcaneus region may be used as parameters in the evaluation of osteoporosis using our new system.398227828