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- Análise sensorial de mel: revisão bibliográficaPublication . dos Santos, Pedro Emanuel Jarmela; Santos, Ana Sofia Gonçalves; Mateus, Teresa Susana LetraO mel é um produto natural complexo, que pode ter origem no néctar (mel de néctar) e/ou em outras soluções açucaradas (mel de melada). Por ser um produto natural, as propriedades sensoriais dependem de uma variedade de fatores, uns controláveis e outros não controláveis pelo Homem. Desta forma, a avaliação das características sensoriais constitui um parâmetro fundamental na determinação da qualidade do mel. A análise sensorial, é um método que permite de uma forma rápida, fiável e barata, identificar e mensurar determinadas propriedades de um produto através da utilização dos diferentes sentidos. Usando técnicas específicas direcionadas para o objetivo da análise, sob o cumprimento de determinadas condições ambientais, será possível caraterizar o produto em questão. No mel, a análise sensorial permite distinguir a origem botânica, identificar certos defeitos, contribuir para a definição de normas e controlo de determinados rótulos específicos, nomeadamente dos méis monoflorais; além disso, é também um elemento fulcral em estudos de preferência/aversão do consumidor. Apesar de estarem descritas várias metodologias de análise sensorial de mel, ainda não foi eleita nenhuma como referência para servir determinado objetivo de análise. Revela-se pois importante, a harmonização de determinadas técnicas recentes, particularmente para a determinação do carácter monofloral do mel, bem como a continuação do uso de técnicas tradicionais, em áreas em que por motivos económicos e/ou práticos, não seja exequível o uso de técnicas mais recentes e onerosas.
- Search for new physics with the M$_{T2}$ variable in all-jets final states produced in pp collisions at $ \sqrt{s}=13 $ TeVPublication . CMS collaboration (2270 authors); Calpas, Betty; Nayak, Aruna; Bargassa, Pedrame; Beirão Da Cruz E Silva, Cristóvão; Di Francesco, Agostino; Faccioli, Pietro; Ferreira Parracho, Pedro Guilherme; Gallinaro, Michele; Hollar, Jonathan; Leonardo, Nuno; Lloret Iglesias, Lara; Rodrigues Antunes, Joao; Seixas, Joao; Toldaiev, Oleksii; Vadruccio, Daniele; Varela, Joao; Vischia, Pietro; David Tinoco Mendes, Andre; Silva, Pedro; Musella, Pasquale; Pela, JoaoA search for new physics is performed using events that contain one or more jets, no isolated leptons, and a large transverse momentum imbalance, as measured through the M$_{T2}$ variable, which is an extension of the transverse mass in events with two invisible particles. The results are based on a sample of proton-proton collisions collected at a center-of-mass energy of 13 TeV with the CMS detector at the LHC, and that corresponds to an integrated luminosity of 2.3 fb$^{−1}$. The observed event yields in the data are consistent with predictions for the standard model backgrounds. The results are interpreted using simplified models of supersymmetry and are expressed in terms of limits on the masses of potential new colored particles. Assuming that the lightest neutralino is stable and has a mass less than about 500 GeV, gluino masses up to 1550-1750 GeV are excluded at 95% confidence level, depending on the gluino decay mechanism. For the scenario of direct production of squark-antisquark pairs, top squarks with masses up to 800 GeV are excluded, assuming a 100% branching fraction for the decay to a top quark and neutralino. Similarly, bottom squark masses are excluded up to 880 GeV, and masses of light-flavor squarks are excluded up to 600-1260 GeV, depending on the degree of degeneracy of the squark masses.
- Measurements of top-quark pair differential cross-sections in the lepton+jets channel in $pp$ collisions at $\sqrt{s}=8$ TeV using the ATLAS detectorPublication . ATLAS collaboration (2871 authors); Aguilar-Saavedra, Juan Antonio; Amor Dos Santos, Susana Patricia; Anjos, Nuno; Araque, Juan Pedro; Cantrill, Robert; Carvalho, João; Castro, Nuno Filipe; Conde Muiño, Patricia; Da Cunha Sargedas De Sousa, Mario Jose; Fiolhais, Miguel; Galhardo, Bruno; Gomes, Agostinho; Gonçalo, Ricardo; Jorge, Pedro; Lopes, Lourenco; Machado Miguens, Joana; Maio, Amélia; Maneira, José; Onofre, António; Palma, Alberto; Pedro, Rute; Pina, João Antonio; Santos, Helena; Saraiva, João; Silva, José; Tavares Delgado, Ademar; Veloso, Filipe; Wolters, HelmutMeasurements of normalized differential cross-sections of top-quark pair production are presented as a function of the top-quark, $t\bar{t}$ system and event-level kinematic observables in proton–proton collisions at a centre-of-mass energy of $\sqrt{s}=8\,\mathrm{TeV}$ . The observables have been chosen to emphasize the $t\bar{t}$ production process and to be sensitive to effects of initial- and final-state radiation, to the different parton distribution functions, and to non-resonant processes and higher-order corrections. The dataset corresponds to an integrated luminosity of 20.3 fb$^{-1}$ , recorded in 2012 with the ATLAS detector at the CERN Large Hadron Collider. Events are selected in the lepton+jets channel, requiring exactly one charged lepton and at least four jets with at least two of the jets tagged as originating from a b-quark. The measured spectra are corrected for detector effects and are compared to several Monte Carlo simulations. The results are in fair agreement with the predictions over a wide kinematic range. Nevertheless, most generators predict a harder top-quark transverse momentum distribution at high values than what is observed in the data. Predictions beyond NLO accuracy improve the agreement with data at high top-quark transverse momenta. Using the current settings and parton distribution functions, the rapidity distributions are not well modelled by any generator under consideration. However, the level of agreement is improved when more recent sets of parton distribution functions are used.
- Search for ultrarelativistic magnetic monopoles with the Pierre Auger ObservatoryPublication . Pierre Auger collaboration (413 authors); Abreu, Pedro; Andringa, Sofia; Assis, Pedro; Barreira Luz, Ricardo Jorge; Blanco, Alberto; Cazon, Lorenzo; Conceição, Ruben; Diogo, Francisco; Espadanal, João; Lopes, Luis; Pimenta, Mário; Santos, Eva; Sarmento, Raul; Tomé, BernardoWe present a search for ultra-relativistic magnetic monopoles with the Pierre Auger Observatory. Such particles, possibly a relic of phase transitions in the early universe, would deposit a large amount of energy along their path through the atmosphere, comparable to that of ultrahigh-energy cosmic rays (UHECRs). The air shower profile of a magnetic monopole can be effectively distinguished by the fluorescence detector from that of standard UHECRs. No candidate was found in the data collected between 2004 and 2012, with an expected background of less than 0.1 event from UHECRs. The corresponding 90% confidence level (C.L.) upper limits on the flux of ultra-relativistic magnetic monopoles range from $10^{-19}$ (cm$^{2}$ sr s)$^{-1}$ for a Lorentz factor $\gamma=10^9$ to $2.5 \times10^{-21}$ (cm$^{2}$ sr s)$^{-1}$ for $\gamma=10^{12}$. These results - the first obtained with a UHECR detector - improve previously published limits by up to an order of magnitude.