4,794 research outputs found

    Numerical simulation of transparent glass-GFRP composite beams using smeared crack models

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    This paper describes results of experimental and numerical investigations about the structural behaviour of composite beams made of annealed glass panes and GFRP pultruded profiles. A brief description of flexural tests previously carried out on glass and glass-GFRP composite beams is first presented. The second part of this paper describes the numerical simulation of a rectangular glass-GFRP composite beam. Two-dimensional finite element (FE) models of the composite beam were developed in order to simulate and analyse their serviceability behaviour (prior to glass breakage) as well as their post-cracking behaviour until the failure. To this end, a multi-fixed smeared crack model was used, and the effects of the following parameters were evaluated: (i) fracture energy of glass and (ii) shear retention factor. Experimental and numerical results are compared regarding the cracking load and post-cracking behaviour, namely in terms of crack pattern and load-deflection response.(undefined

    Experimental investigations on continuous glass-GFRP beams: preliminary nonlinear numerical modelling

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    This paper describes results of experimental and numerical investigations about the structural behaviour of composite beams made of annealed glass panes and GFRP pultruded profiles. A brief description of flexural tests previously carried out on simply supported glass and glass-GFRP composite beams is first presented. Then, results of flexural tests on two-span glass-GFRP composite beams, bonded with three different structural adhesives, are described in detail. Finally, a preliminary numerical study of the glass-GFRP composite simply supported beams is presented. In this study, two-dimensional finite element models were developed in order to simulate and analyse the serviceability and post-cracking behaviour of those beams. Experimental and numerical results presented in this paper prove the advantages and technical viability of glass-GFRP composite beams

    Construction of a novel and safe S. cerevisiae biocatalyst for lactulose production

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    Prebiotics are defined as substrates that are utilized by host microorganisms conferring a health benefit. These compounds have been incorporated in a wide variety of food products1. One of the most well-recognized prebiotics is lactulose. Lactulose is not found naturally so it has to be produced through different methods: chemical or enzymatic synthesis and electro-activation2. Recently, the production of lactulose through lactose isomerization catalyzed by cellobiose 2- epimerase from Caldicellulosiruptor saccharolyticus (CsCE) was reported3. This strategy is gaining attention as a preferable methodology for industrial application due to its notable yields. Saccharomyces cerevisiae, one of the most well-characterized microorganisms, is widely used for the heterologous production of several enzymes, also due to the diverse genetic manipulating tools that are currently available. Here, we propose a new and promising S. cerevisiae biocatalyst. Taking advantage of its GRAS status and using lactose as a single substrate, we believe that it can be a more economic and attractive approach for the synthesis of lactulose. The CsCE gene was cloned in the CEN.PK2-1C S. cerevisiae strain, under TEF or GAP promoters control. Both biocatalysts were used in lactulose production, reaching a concentration of 1.26 g/L (TEF promoter) and 2.15 g/L (GAP promoter). The maximum prebiotic yield was 6.20%. These promising results represent the first use of a S. cerevisiae biocatalyst for lactulose production and demonstrated its potential as a sustainable and safe approach for food application.BBC acknowledge her doctoral grant (SFRH/BD/132324/2017) from the Portuguese Foundation of Science and Technology (FCT). This study was supported by FCT under the scope of the strategic funding of UID/BIO/04469/2019 unit, the Project FoSynBio (POCI-01-0145-FEDER-029549) and BioTecNorte operation (NORTE-01-0145-FEDER000004) funded by the European Regional Development Fund under the scope of Norte2020 - Programa Operacional Regional do Norte.info:eu-repo/semantics/publishedVersio

    The adoption of cloud computing by SMEs: identifying and coping with external factors.

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    Comunicação apresentada na CAPSI 2011 - 11ª Conferência da Associação Portuguesa de Sistemas de Informação – A Gestão de Informação na era da Cloud Computing, Lisboa, ISEG/IUL-ISCTE/, 19 a 21 de Outubro de 2011.The recent development of Cloud Computing (CC) provides a convincing opportunity for organizations to outsource their Information and Communications Technology (ICT). Although its popularity is increasing rapidly, there are concerns that must be taken into account. This paper ascertains the most relevant issues associated with the political, economic, social and technological factors concerning CC adoption. The research described is based on a scoping review to identify relevant studies published in the literature recently. The aim is to provide an overview of the most recent findings in the Cloud Computing environment, which can inform strategic decision-making by Small to Medium-sized Enterprises (SMEs) in this area

    Enzymatic synthesis of lactulose using a novel biocatalyst

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    Agro-industrial wastes as alternative substrates for the production of prebiotic with Zymomonas mobilis

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    Fructooligosaccharides (FOS) are promising prebiotics in the relevant and increasing market of functional food. However, to achieve a more sustainable process, the industrial production of FOS should use cheap substrates. Zymomonas mobilis (ZM) has great potential for the production of FOS due to the presence of native enzymes (levansucrase) capable of metabolizing sucrose. In addition, ZM can use different carbon sources, such as molasses and sugarcane juice, which make the FOS production process cost-effective. In this study, sugarcane molasses (a potential replacement of sucrose) and corn step liquor (CSL) (a potential replacement of yeast extract (YE)), were used as nutrients for FOS production using ZM in an in vivo bioprocess approach. FOS production process from sucrose was first optimized and 52 g/L of FOS with a yield of 0.16 g/g was obtained. Afterwards, molasses and CSL were used as alternative nutrients. After studying different combinations of CSL and YE, the highest amount of FOS (54 g/L, with a yield of 0.18 g/g) was obtained with 12 g/L of CSL and 8 g/L of YE. In addition, 45 g/L of FOS were produced from molasses containing 200 g/L of sucrose, with a yield of 0.3 g/g. With this approach, it was possible to reduce around 5.5-times the cost associated with the FOS production medium. Moreover, this study proposed a sustainable process for the valorization of agro-industrial wastes contributing to the future Circular (Bio)Economy and the EU Green Deal.Cláudia Amorim, João Rainha, Beatriz B. Cardoso and Daniela Gomes acknowledge their grants (2020.0029.CEECIND, SFRH/BD/138325/2018, SFRH/BD/132324/2017 and SFRH/BD/04433/2020, respectively) from Portuguese Foundation for Science and Technology (FCT). The study received financial support from Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UIDB/04469/2020 unit and by LABBELS – Associate Laboratory in Biotechnology, Bioengineering and Microelectromechanical Systems, LA/P/0029/2020.info:eu-repo/semantics/publishedVersio

    A full-scale innovative GFRP-concrete hybrid footbridge : description and testing

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    The present paper describes the construction process of a full-scale innovative GFRP-concrete hybrid footbridge, and summarizes the main tests performed. This footbridge is 11 m long, 2 m wide, simply supported, and composed of two pultruded I-shaped GFRP girders (0.2 m x 0.4 m) and a 0.04 thick deck in steel fiber reinforced self-compacting concrete (SFRSCC). To evaluate the static and dynamic behavior of this footbridge, short and long-term load tests, and dynamic tests were performed.(undefined

    Interstitial deletion on chromosome 14q in prenatal diagnosis

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    A limited number of prenatal diagnosis (PND) cases have reported interstitial deletions of the long arm of chromosome 14 involving the 14q31-32 region. Those cases presented cardiac anomalies, urogenital anomalies, congenital diaphragmatic hernia, and mild pyelectasis. We report the PND of a 33-year-old pregnant woman, who underwent chorionic villus sampling at 12 weeks of gestation after a positive combined 1st trimester screen. The karyotype revealed a 14q interstitial deletion. Amniocentesis was performed at 18 weeks of gestation to confirm the deletion and to exclude a confined placental mosaicism and a microarray analysis was performed in order to accurately define the deletion breakpoints. Cytogenetics analysis revealed a karyotype 46,XY,del(14)(q31q32.2)dn. Microarray analysis allowed to redefined the breakpoints accurate localization and the identification of a ~21Mb deletion (arr[hg19] 14q31.1q32.31(79917376_101568230)x1). At 18 weeks of gestation the fetus presented abnormal fetal biometric parameters (occipitofrontal diameter, cephalic perimeter and abdominal circumference) on ultrasound. After counseling the couple opted for pregnancy termination. The postmorten analysis presented decreased biometry, low weight and low fetal size, facial dysmorphism, clinodactyly, club foot, overlapping fingers and short penis. In internal habitus he presented thymus hypoplasia, bladder hypoplasia, and horseshoe kidneys. The genotype-phenotype correlation in PND pure del(14q) cases is not well established. Furthermore, to our knowledge, del(14q) had not been reported so early in the gestation yet. In this case the positive 1st trimester screen was related to the inverted ductus venosus and low PAPP-A value. The urogenital anomalies (as horseshoe kidneys) and biometry anomalies are described in the literature. However, to our knowledge, some features of the present case were not seen in other reported cases, for instance clinodactyly, club foot, overlapping fingers, thymus hypoplasia and bladder hypoplasia. Other reports described cardiac and cerebral anomalies, diaphragmatic hernia, and also UPD(14)like phenotypes, which are possibly liked to the 14q32 imprinted region. The establishment of a phenotype-genotype correlation is difficult given the size of the deletion, which includes a large number of genes in distinct regions. Nevertheless, this work contributes to a better identification of additional features associated to del(14q) that can be present in PND.info:eu-repo/semantics/publishedVersio
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