1,939 research outputs found

    CFRP group effect and interaction between stirrups and strips on the NSM-shear strengthening of RC beams

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    Available experimental research shows that the technique based on installing Carbon Fibre Reinforced Polymer (CFRP) strips into slits opened on the cover concrete of the beam’s lateral faces, designated as Near Surface Mounted (NSM), is very effective to increase the shear resistance of reinforced concrete (RC) beams. However, recent research has revealed that, in terms of NSM shear strengthening effectiveness, a detrimental effect can occur between existing steel stirrups and applied strips, as well as amongst the strips when the distance between strips, sf, is lower than a certain limit. In the present work, a test setup was developed and an experimental program was carried out to assess the influence of both sf and interaction between existing steel stirrups and strips on the shear strengthening of RC beams. The experimental program is described and the main results are presented and analyzed.(13-05-04-FDR-00031

    Long-range dependencies of euronext capital markets: A dynamic detrended analysis

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    This paper aims to test efficiency, in its weak form, in the capital markets of the Netherlands (AEX), Belgium (BEL 20), France (CAC 40), Ireland (ISEQ 20), Norway (OSEBX), Portugal (PSI 20), in the period from April 4, 2019 to April 1, 2021. The sample was partitioned into two subperiods, the first and second wave of the global pandemic: April 4, 2019 to April 30, 2020; May 4, 2020 to April 1, 2021. To carry out this analysis, different approaches were undertaken to analyze whether: (i) Euronext’s stock markets have more significant long memories in the first or second wave of the global pandemic? The results show the presence of sharp long memories during the first wave of the global pandemic, particularly in the stock indices OSEBX (0.67), PSI 20 (0.67), AEX (0.66), BEL 20 (0.64), CAC 40 (0.62), ISEQ 20 (0.61), which implies that the yields are autocorrelated in time and, there is a reversal of the average, in all indexes. Regarding the second wave of the global pandemic, we found that most Euronext stock markets don’t reject the random walk hypothesis, with the exception of the Norwegian (0.56) and Portugal (0.55) stock markets. These findings show that the impact of the Covid-19 pandemic was accentuated during the first wave, but from May 2020 the markets adjusted and showed balance. The authors believe that the results achieved will be a benefit to international investors seeking efficient diversification into their portfolios.info:eu-repo/semantics/publishedVersio

    The 2020 oil price war has increased integration between G7 stock markets and crude oil WTI

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    This paper aims to examine whether the oil price war between Saudi Arabia and Russia has increased integration between the Crude Oil WTI Spot oil index and the G7 stock markets, namely France (CAC 40), Germany (DAX 30), USA (DOW JONES), UK (FTSE 100), Italy (FTSE MID), Japan (Nikkei 225), Canada (S&P TSX), from January 2018 to January 2021. The results show that in the period before the oil price war, the G7 stock markets and the WTI index had 29 integrations (out of 56 possible). The WTI index is integrated with the UK stock markets (FTSE 100), and Japan (NIKKEI 225), and is integrated into the Japanese market. In the period of the oil price war, the G7’s stock markets and the Crude Oil WTI Spot index had 43 integrations (out of 56 possible), namely the WTI, Dow Jones, and Nikkei 225 indexes, with all their peers (7 out of 7 possible). When comparing the period before and during the 2020 oil crash, we found that integrations increased significantly from 29 to 43 (out of 56 possible); we also found that the Crude Oil WTI Spot index is no longer a safe haven for portfolio diversification in G7 stock markets. These findings validate our research issue, i.e., the oil price war between Saudi Arabia and Russia had increased integrations, and this evidence could question portfolio diversification.info:eu-repo/semantics/publishedVersio

    On the mechanical, thermoelectric, and excitonic properties of Tetragraphene monolayer

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    Two-dimensional carbon allotropes have attracted much attention due to their extraordinary optoelectronic and mechanical properties, which can be exploited for energy conversion and storage applications. In this work, we use density functional theory simulations and semi-empirical methods to investigate the mechanical, thermoelectric, and excitonic properties of Tetrahexcarbon (also known as Tetragraphene). This quasi-2D carbon allotrope exhibits a combination of squared and hexagonal rings in a buckled shape. Our findings reveal that tetragraphene is a semiconductor material with a direct electronic bandgap of 2.66 eV. Despite the direct nature of the electronic band structure, this material has an indirect exciton ground state of 2.30 eV, which results in an exciton binding energy of 0.36 eV. At ambient temperature, we obtain that the lattice thermal conductivity for tetragraphene is approximately 118 W/mK. Young's modulus and the shear modulus of tetragraphene are almost isotropic, with maximum values of 286.0 N/m and 133.7 N/m, respectively, while exhibiting a very low anisotropic Poisson ratio value of 0.09

    The impact of plant-based coatings in “ROCHA” pear preservation during cold storage: a metabolomic approach

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    Although new storage technologies have been emerging in recent years, preservation of pear (Pyrus communis L.) remains a challenge for suppliers. Maintenance of desired organoleptic properties throughout cold storage using non-chemical strategies has been investigated and the use of edible coatings has shown potential to delay fruit quality deterioration during cold storage. Thus, the objective of this study is to evaluate the impact of pectin coatings including plant extracts, in “Rocha” pear (Pyrus communis L. cv. Rocha) preservation. A four-month pilot scale assay was performed in both dynamic controlled atmosphere (DCA) (−0.5 °C, 0.5% O2, and 0.4% CO2) and normal atmospheric (NA) conditions (2 °C). For each storage condition, the following three coatings were tested: pectin (3% w/v) (PCT), pectin (3% w/v) + strawberry tree leaves extract (9.5 mg/mL) (CT1), and pectin (3% w/v) + apple pomace extract (16 mg/mL) (CT2). Volatile compounds, potentially related to aroma or ripening status of “Rocha” pear, were monitored alongside with conjugated trienols (CTs) and maturity parameters. The combination of DCA conditions and the application of pectin coatings were able to reduce the release of Rocha pear volatiles associated with ripening status, (particularly esters and sesquiterpenes), as well as reduce CTs, which could contribute to the preservation of Rocha pear for longer periods.info:eu-repo/semantics/publishedVersio

    Synthesis and enzymatic evaluation of the guanosine analogue 2-amino-6-mercapto-7-methylpurine ribonucleoside (MESG): insights into the phosphorolysis reaction mechanism based on the blueprint transition state: SN1 or SN2?

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    A modified experimental procedure for the synthesis of MESG (2-amino-6-mercapto-7-methylpurine ribonucleoside) 1 has been successfully performed and its full characterization is presented. High resolution ESI(+)-MSMS indicates both the nucleoside bond cleavage as the main fragmentation in the gas phase and a possible SN1 mechanism. Ab initio transition state calculations based on the blue print transition state support this mechanistic rationale and discard an alternative SN2 mechanism. Assays using purine nucleoside phosphorylase (PNP) enzyme (human and M. tuberculosis sources) indicate its efficiency in the phosphorolysis of MESG and allow the quantitative determination of inorganic phosphate in real time assay

    The revolving door : evidence from the United Kingdom, Germany, France, Spain, Belgium, Greece and Brazil

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    The following study analyses the academic background and careers of 175 members of Governments and Central Banks of seven countries (Belgium, Brazil, France, Germany, Greece, Spain and United Kingdom) for the years 1975 and 2015, in order to verify whether the “Revolving Door Theory” can be applied to these cases. After some research on the curricula vitae of the members of Governments and Central Banks, we found that, for instance, that more Government and Central Bank members studied abroad for the case of the UK and US than for the other countries. We also found that it is more common for Central Bank executive members to obtain PhDs than it is the case for Government members. Moreover, external promotions in the Central Banks in 1975 were quite relevant but no cases were registered for 2015; for Governments, the trend was the exact opposite, no external promotions in 1975 but many cases in 2015. While it is not possible to find irrefutable evidence to sustain the Revolving Door hypothesis, it is still possible to find recurrent patterns in different countries that may be explained by that theory. More expanded databases and a larger selection of countries is required for that analysis

    Tlx3 exerts direct control in specifying excitatory over inhibitory neurons in the dorsal spinal cord

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    © 2021 Monteiro, Miranda, Samina, Dias, Raposo, Oliveira, Reguenga, Castro and Lima. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.The spinal cord dorsal horn is a major station for integration and relay of somatosensory information and comprises both excitatory and inhibitory neuronal populations. The homeobox gene Tlx3 acts as a selector gene to control the development of late-born excitatory (dILB) neurons by specifying glutamatergic transmitter fate in dorsal spinal cord. However, since Tlx3 direct transcriptional targets remain largely unknown, it remains to be uncovered how Tlx3 functions to promote excitatory cell fate. Here we combined a genomics approach based on chromatin immunoprecipitation followed by next generation sequencing (ChIP-seq) and expression profiling, with validation experiments in Tlx3 null embryos, to characterize the transcriptional program of Tlx3 in mouse embryonic dorsal spinal cord. We found most dILB neuron specific genes previously identified to be directly activated by Tlx3. Surprisingly, we found Tlx3 also directly represses many genes associated with the alternative inhibitory dILA neuronal fate. In both cases, direct targets include transcription factors and terminal differentiation genes, showing that Tlx3 directly controls cell identity at distinct levels. Our findings provide a molecular frame for the master regulatory role of Tlx3 in developing glutamatergic dILB neurons. In addition, they suggest a novel function for Tlx3 as direct repressor of GABAergic dILA identity, pointing to how generation of the two alternative cell fates being tightly coupled.This work is a result of the project Norte-01-0145-FEDER-000008 – Porto Neurosciences and Neurologic Disease Research Initiative at I3S, supported by Norte Portugal Regional Operational Program (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). This work was also supported by FCT – Fundação para a Ciência e Tecnologia (Grants PTDC/SAU-OBD/099886/2008 to DL and PTDC/NEU-NMC/0315/2012 to DC) and Universidade do Porto/Banco Santander Totta (Projetos Pluridisciplinares to FM). We acknowledge the support of POCI-01-0145-FEDER-022122, granted to i3S Scientific Platform Advanced Light Microscopy, member of the national infrastructure PPBI-Portuguese Platform of BioImaging.info:eu-repo/semantics/publishedVersio

    Explaining the Higgs Decays at the LHC with an Extended Electroweak Model

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    We show that the recent discovery of a new boson at the LHC, which we assume to be a Higgs boson, and the observed enhancement in its diphoton decays compared to the SM prediction, can be explained by a new doublet of charged vector bosons from an extended electroweak gauge sector model with SU(3)_C\otimesSU(3)_L\otimesU(1)_X symmetry. Our results show a good agreement between our theoretical expected sensitivity to a 126--125 GeV Higgs boson and the experimental significance observed in the diphoton channel at the 8 TeV LHC. Effects of an invisible decay channel for the Higgs boson are also taken into account, in order to anticipate a possible confirmation of deficits in the branching ratios into ZZZZ^*, WWWW^*, bottom quarks, and tau leptons.Comment: 16 pages, 5 figure
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