1,019 research outputs found
The Effect of Bond-Slip in the Numerical Assessment of RC Frames Under Cyclic Loading
Bond-slip may have significant influence on the assessment, with numerical models, of reinforced concrete structures
subjected to cyclic loadings, whether static or dynamic. Its influence is discussed with the correlation of experimental and
analytical results, where two numerical models are considered, including a perfect bond fiber-section finite element
formulation and a force-based fiber-section model including bond-slip in the vicinity of the frame joints, both exterior and
interior. In this case, the model implemented makes it possible to consider the coupling effect of the response of the beams
adjacent to the joint, and the models are constructed from the geometrical and material characteristics of the structure,
without any calibration procedures. The experimental results are from a reinforced concrete column and a beam-column
subassemblage, both subjected to static cyclic loadings, with predefined displacements sequences for the element-ends, and
from a shaking table test of a one bay two-story reinforced concrete frame structure.
The comparisons show that the considered bond-slip based model makes it possible to satisfactorily predict the response of
reinforced concrete frames under both static and dynamic cyclic loadings. The influence of reinforcement slippage was
evaluated by comparison of the previous results with those obtained with the perfect bond-based model. This made it
possible to conclude that the accuracy of the model considering bond-slip is significantly superior to that of the perfect bond
model. Furthermore, responses obtained with the previous model show the pinching effect, which is characteristic of
reinforced concrete structures and significantly changes the hysteretic dissipated energy, not delivered by the latter model.
This can also be seen in the effect of bond-slip in the response of the fibers which model the reinforcing rebars.info:eu-repo/semantics/publishedVersio
Emotional and mental nuances and technological approaches: Optimising Fact-Check dissemination through cognitive reinforcement technique †
The issue of the dissemination of fake news has been widely addressed in the literature, but the issue of the dissemination of fact checks to debunk fake news has not received sufficient attention. Fake news is tailored to reach a wide audience, a concern that, as this paper shows, does not seem to be present in fact checking. As a result, fact checking, no matter how good it is, fails in its goal of debunking fake news for the general public. This paper addresses this problem with the aim of increasing the effectiveness of the fact checking of online social media posts through the use of cognitive tools, yet grounded in ethical principles. The paper consists of a profile of the prevalence of fact checking in online social media (both from the literature and from field data) and an assessment of the extent to which engagement can be increased by using simple cognitive enhancements in the text of the post. The focus is on Snopes and (Formula presented.) (formerly Twitter).FCT -Fundação para a Ciência e a Tecnologia(2022.06822
Development of nickel-based magnetoliposomes
Liposomes entrapping nickel-based magnetic nanoparticles (magnetoliposomes) were prepared and characterized.This work was supported by FEDER through the COMPETE Program and by the Portuguese Foundation for Science and Technology (FCT) in the framework of the Strategic Project of CFUM [PEst-C/FIS/UI0607/2011 (F-COMP-01-0124-FEDER-022711)]. FCT is also acknowledged for the PhD grant of A.R.O. Rodrigues (SFRH/BD/90949/2012)
Magnetoliposomes based on magnetite nanoparticles
In this work, magnetic nanoparticles of magnetite were prepared by soft chemical methods, using different surfactants as templating media. These nanoparticles were either covered with a lipid bilayer, forming dry magnetoliposomes, or entrapped in liposomes - aqueous magnetoliposomes.FCT, FEDER, COMPETE/QREN/EU for financial support to CFUM (Strategic Project PEst-C/FIS/UI0607/2011) and to the research project PTDC/QUI/81238/2006 (FCOMP-01-0124-FEDER-007467)
Stealth magnetoliposomes based on calcium-substituted magnesium ferrite nanoparticles for curcumin transport and release
Despite the promising pharmacological properties of curcumin, the transport and effective release of curcumin is still a challenge. The advances in functionalized nanocarriers for curcumin have also been motivated by the anticancer activity of this natural compound, aiming at targeted therapies. Here, stealth (aqueous and solid) magnetoliposomes containing calcium-substituted magnesium ferrite nanoparticles, CaxMg1−xFe2O4 (with x = 0.25, 0.50, 0.75) were developed as nanocarriers for curcumin. The magnetic nanoparticles exhibit superparamagnetic properties and crystalline structure, with sizes below 10 nm. The magnetoliposomes based on these nanoparticles have hydrodynamic diameters around or below 150 nm and a low polydispersity. The influence of an alternating magnetic field (AMF) on drug release over time was evaluated and compared with curcumin release by diffusion. The results suggest the potential of drug-loaded magnetoliposomes as nanocarriers that can be magnetically guided to the tumor sites and act as agents for a synergistic effect combining magnetic hyperthermia and controlled drug release.This research was funded by the Portuguese Foundation for Science and Technology (FCT) in the
framework of the Strategic Funding of CF-UM-UP (UID/FIS/04650/2019) and through the research project
PTDC/QUI-QFI/28020/2017 (POCI-01-0145-FEDER-028020), financed by European Fund of Regional Development (FEDER), COMPETE2020 and Portugal2020. The magnetic measurements were supported by projects UTAP-EXPL/NTec/0046/2017, NORTE-01-0145-FEDER-028538 and PTDC/FIS-MAC/29454/2017. The APC was also funded by FCT. B.D.C. acknowledges FCT for a PhD grant (SFRH/BD/141936/2018)
Efeitos de Ácidos da Dieta na Microdureza e na Rugosidade de Superfície de Resinas de PMMA para Restaurações Temporárias em Prótese Fixa
Magnetoliposomes containing magnesium ferrite nanoparticles for enhanced therapeutic potential of curcumin
In this work, magnesium ferrite nanoparticles with superparamagnetic behavior and sizes around 20 nm were prepared and characterized. The structural and magnetic properties of these nanoparticles were evaluated by XRD, SEM and SQUID. In order to further develop applications in cancer therapy, the prepared MgFe2O4 nanoparticles were covered with a lipid bilayer (solid magnetoliposomes) or incorporated in lipid vesicles, forming aqueous magnetoliposomes.info:eu-repo/semantics/publishedVersio
Body growth and phenotypic variation of the carcasses of native duck lineages (Cairina moschata)
Natives ducks are birds that require little handling and are resistant to many diseases that affect chickens. Thus, they adapt to low-input farming conditions, which contributes to the food security of small farmers. Although they exhibit potential for growth, their production characteristics are relatively unknown, so they are underexploited. The objective of this study was to compare how nonlinear models fit the growth curve of two genetic groups of duck and to evaluate variation based on carcass characteristics. Two hundred and twenty four animals were weighed weekly, from birth to 90 days of age. We used nonlinear models (Brody, Richards, Gompertz, Von Bertalanff and Logistic) to describe growth curve. For the evaluation of phenotypic variation, we measured seven carcass traits from 81 ducks carried out by principal component analysis. The logistic model best fit the growth curve, and the absolute growth rates (AGR) for the Catolé duck showed that females reached their maximum AGR at approximately 30 days but did not reach their ideal commercial weight. The drumstick, thigh and liver yields accounted for 41.17% of the differences between the Catolé and Paysandu ducks. The slaughter of male Catolé ducks is recommended between 70 and 90 days because a drastic decrease in growth occurs after this time. For the slaughter of females, feeding management modifications and improvement in growth indices are recommended to increase the final weight and AGR. The carcass yields indicate potential for native duck meat production
Obtenção de dados meteorológicos para sistemas de alerta fitossanitário: o caso da duração do período de molhamento foliar
Disease-warning systems are decision support tools designed to help growers determine when to apply control measures to suppress crop diseases. Weather data are nearly ubiquitous inputs to warning systems. This contribution reviews ways in which weather data are gathered for use as inputs to disease-warning systems, and the associated logistical challenges. Grower-operated weather monitoring is contrasted with obtaining data from networks of weather stations, and the advantages and disadvantages of measuring vs. estimating weather data are discussed. Special emphasis is given to leaf wetness duration (LWD), not only because LWD data are inputs to many disease-warning systems but also because accurate data are uniquely challenging to obtain. It is concluded that there is no single best method to acquire weather data for use in disease-warning systems; instead, local, regional, and national circumstances are likely to influence which strategy is most successful.Os sistemas de alerta fitossanitário são ferramentas de suporte à decisão desenvolvidos para ajudar os agricultures a determinar o melhor momento da aplicação das medidas de controle para combater as doenças de plantas. As variáveis meteorológicas são dados de entrada quase que obrigatórios desses sistemas. Este trabalho apresenta uma revisão sobre os meios pelos quais as variáveis meteorológicas são coletadas para serem usadas como dados de entrada em sistemas de alerta fitossanitário e sobre os desafios associados à logística de obtenção desses dados. Essa revisão compara o monitoramento meteorológico ao nível do produtor, nas propriedades agrícolas, com aquele feito ao nível de redes de estações meteorológicas, assim como discute as vantagens e desvantagens entre medir e estimar tais variáveis meteorológicas. Especial ênfase é dada à duração do período de molhamento foliar (DPM), não somente pela sua importância como dado de entrada em diversos sistemas de alerta fitossanitário, mas também pelo desafio de se obter dados acurados dessa variável. Pode-se concluir, após ampla discussão do assunto, que não há um método único e melhor para se obter os dados meteorológicos para uso em sistemas de alerta fitossanitário; por outro lado, as circunstâncias a nível local, regional e nacional provavelmente influenciam a estratégia de maior sucesso
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