375 research outputs found

    Pyridoxine analysis by high performance liquid chromatography and validation in fortified milk powder

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    Vitamin B6 analysis by reverse-phase high performance liquid chromatography and its validation in milk powder prompted this study. The calibration curves for pyridoxal, pyridoxamine and pyridoxine were evaluated and method precision and accuracy assessed. It was found that the working range was adequate for all the analytes. The analytical procedure was verified by testing the enzymatic efficiency, precision and accuracy. In milk powder samples pyridoxine was the only vitamer found in quantities above the considered limit of quantification and the accuracy showed Z-scores lower than 2. Uncertainty estimation based on method validation results was 0.066 mg/100g, for a vitamin B6 content of 0.61 mg/100 g. It was concluded that the method is adequate for vitamin B6 quantification in powder milk

    Assessment of Woody Residual Biomass Generation Capacity in the Central Region of Portugal: Analysis of the Power Production Potential

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    Biomass is an alternative energy source with high potential to contribute to the global energy mix and to countries’ energetic independence. The case of Portugal is particularly relevant, given its biomass availability. Thus, the quantification of woody residual biomass is assumed to be urgent. To achieve the objective of quantifying residual woody biomass, various available data were used, namely the Land Cover and Soil Use Map (COS 2018), from which areas occupied by different categories were selected as being the most relevant. Then, based on coefficients previously established, the amounts of residual woody biomass were determined, namely for maritime pine forests, eucalyptus forests, scrubland, vineyards, olive groves, and orchards. Then, the potential for generating electricity was estimated. It was found that for the hypothetical scenario of the total conversion of the recently closed Pêgo coal power plant to biomass, the available amounts of residual woody biomass in the country would not be sufficient to ensure the operation. On the other hand, if the power plant only worked as a backup unit, the available quantities could ensure its operation and contribute to creating a value chain for residual woody biomass of forest and agricultural origin within a circular economy and sustainable development approachinfo:eu-repo/semantics/publishedVersio

    Reducing Rural Fire Risk through the Development of a Sustainable Supply Chain Model for Residual Agroforestry Biomass Supported in aWeb Platform: A Case Study in Portugal Central Region with the Project BioAgroFloRes

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    In the European Mediterranean region, rural fires are a widely known problem that cause serious socio-economic losses and undesirable environmental consequences, including the loss of lives, infrastructures, cultural heritage, and ecosystem services such as carbon sequestration and the provisioning of raw materials. In the last decades, the collapse of the traditional rural socioeconomic systems that once characterized the Mediterranean region, along with land-use changes, have created conflicts and additional driving factors for rural fires. Within Europe, Portugal is the most affected country by rural fires. This work intends to demonstrate the importance of recovering and valorizing residual agroforestry biomass to reduce rural fire risk in Portugal, and thus contributing to a fire resilient landscape. From the results of the known causes of fires in Portugal, it becomes very clear that it is crucial to educate people to end risky behaviors, such as the burning of agroforestry leftovers that causes 27% of fires in Portugal each year. The valorization of the existing energy potential in the lignocellulosic biomass of agroforestry residues favors the reduction of the probability of rural fires, this being the focus of the project BioAgroFloRes—Sustainable Supply Chain Model for Residual Agroforestry Biomass supported in a Web Platform—introduced and explained hereinfo:eu-repo/semantics/publishedVersio

    Evidence for muon neutrino oscillation in an accelerator-based experiment

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    We present results for muon neutrino oscillation in the KEK to Kamioka (K2K) long-baseline neutrino oscillation experiment. K2K uses an accelerator-produced muon neutrino beam with a mean energy of 1.3 GeV directed at the Super-Kamiokande detector. We observed the energy dependent disappearance of muon neutrino, which we presume have oscillated to tau neutrino. The probability that we would observe these results if there is no neutrino oscillation is 0.0050% (4.0 sigma).Comment: 5 pages, 4 figure

    Measurement of the correlation between flow harmonics of different order in lead-lead collisions at √sNN = 2.76 TeV with the ATLAS detector

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    Correlations between the elliptic or triangular flow coefficients vm (m=2 or 3) and other flow harmonics vn (n=2 to 5) are measured using √sNN=2.76 TeV Pb+Pb collision data collected in 2010 by the ATLAS experiment at the LHC, corresponding to an integrated luminosity of 7 μb−1. The vm−vn correlations are measured in midrapidity as a function of centrality, and, for events within the same centrality interval, as a function of event ellipticity or triangularity defined in a forward rapidity region. For events within the same centrality interval, v3 is found to be anticorrelated with v2 and this anticorrelation is consistent with similar anticorrelations between the corresponding eccentricities, ε2 and ε3. However, it is observed that v4 increases strongly with v2, and v5 increases strongly with both v2 and v3. The trend and strength of the vm−vn correlations for n=4 and 5 are found to disagree with εm−εn correlations predicted by initial-geometry models. Instead, these correlations are found to be consistent with the combined effects of a linear contribution to vn and a nonlinear term that is a function of v22 or of v2v3, as predicted by hydrodynamic models. A simple two-component fit is used to separate these two contributions. The extracted linear and nonlinear contributions to v4 and v5 are found to be consistent with previously measured event-plane correlations

    Measurement of the cross section for isolated-photon plus jet production in pp collisions at √s=13 TeV using the ATLAS detector

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    The dynamics of isolated-photon production in association with a jet in proton–proton collisions at a centre-of-mass energy of 13 TeV are studied with the ATLAS detector at the LHC using a dataset with an integrated luminosity of 3.2 fb−1. Photons are required to have transverse energies above 125 GeV. Jets are identified using the anti- algorithm with radius parameter and required to have transverse momenta above 100 GeV. Measurements of isolated-photon plus jet cross sections are presented as functions of the leading-photon transverse energy, the leading-jet transverse momentum, the azimuthal angular separation between the photon and the jet, the photon–jet invariant mass and the scattering angle in the photon–jet centre-of-mass system. Tree-level plus parton-shower predictions from Sherpa and Pythia as well as next-to-leading-order QCD predictions from Jetphox and Sherpa are compared to the measurements

    Search for vectorlike B quarks in events with one isolated lepton, missing transverse momentum, and jets at √s = 8 TeV with the ATLAS detector

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    A search has been performed for pair production of heavy vectorlike down-type (B) quarks. The analysis explores the lepton-plus-jets final state, characterized by events with one isolated charged lepton (electron or muon), significant missing transverse momentum, and multiple jets. One or more jets are required to be tagged as arising from b quarks, and at least one pair of jets must be tagged as arising from the hadronic decay of an electroweak boson. The analysis uses the full data sample of pp collisions recorded in 2012 by the ATLAS detector at the LHC, operating at a center-of-mass energy of 8 TeV, corresponding to an integrated luminosity of 20.3 fb −1 . No significant excess of events is observed above the expected background. Limits are set on vectorlike B production, as a function of the B branching ratios, assuming the allowable decay modes are B → Wt/Zb/Hb. In the chiral limit with a branching ratio of 100% for the decay B → Wt, the observed (expected) 95% C.L. lower limit on the vectorlike B mass is 810 GeV (760 GeV). In the case where the vectorlike B quark has branching ratio values corresponding to those of an SU(2) singlet state, the observed (expected) 95% C.L. lower limit on the vectorlike B mass is 640 GeV (505 GeV). The same analysis, when used to investigate pair production of a colored, charge 5/3 exotic fermion T 5/3 , with subsequent decay T 5/3 → Wt, sets an observed (expected) 95% C.L. lower limit on the T 5/3 mass of 840 GeV (780 GeV)

    Search for W′→tb→qqbb decays in pp collisions at √s=8 TeV with the ATLAS detector

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    A search for a massive W′ gauge boson decaying to a top quark and a bottom quark is performed with the ATLAS detector in pp collisions at the LHC. The dataset was taken at a centre-of-mass energy of √s=8 TeV and corresponds to 20.3 fb−1 of integrated luminosity. This analysis is done in the hadronic decay mode of the top quark, where novel jet substructure techniques are used to identify jets from high-momentum top quarks. This allows for a search for high-mass W′ bosons in the range 1.5–3.0 TeV. b-tagging is used to identify jets originating from b-quarks. The data are consistent with Standard Model background-only expectations, and upper limits at 95 % confidence level are set on the W′→tb cross section times branching ratio ranging from 0.16pb to 0.33pb for left-handed W′ bosons, and ranging from 0.10pb to 0.21pb for W′ bosons with purely right-handed couplings. Upper limits at 95 % confidence level are set on the W′-boson coupling to tb as a function of the W′ mass using an effective field theory approach, which is independent of details of particular models predicting a W′boson
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