25 research outputs found

    Low severity pretreatment for production of xylooligosaccharides from two varieties of energy cane

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    Orientadores: Telma Teixeira Franco, Sarita C√Ęndida RabeloDisserta√ß√£o (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Qu√≠micaResumo: A cana-energia √© uma fonte de biomassa promissora para estudos de etapas de pr√©-tratamento, pois possui alto teor de fibras e baixo teor de sacarose, possibilitando a produ√ß√£o de produtos de alto valor agregado, al√©m de etanol de segunda gera√ß√£o. Neste sentido, o presente trabalho teve como objetivo avaliar a produ√ß√£o de xilooligossacar√≠deos (XOS) a partir de duas variedades de cana-energia, empregando a otimiza√ß√£o de um pr√©-tratamento sequencial (desacetila√ß√£o seguida por pr√©-tratamento hidrot√©rmico). A primeira etapa teve como objetivo remover os grupos acetila ligados √† cadeia hemicelul√≥sica sendo estudados os par√Ęmetros operacionais como tempo, temperatura e concentra√ß√£o de hidr√≥xido de s√≥dio. Os resultados mostraram que a condi√ß√£o mais branda avaliada (15 min, 40¬įC e 60 mgNaOH/gbiomassa) promoveu uma solubiliza√ß√£o de 74,3 ¬Ī 2,8% de grupos acetila para o baga√ßo de cana-energia da empresa Granbio e 82,2 ¬Ī 1,8% para a cana-energia integral da empresa Vignis. Na segunda etapa, as condi√ß√Ķes operacionais do pr√©-tratamento hidrot√©rmico foram otimizadas utilizando o material desacetilado otimizado, com o intuito de maximizar a solubiliza√ß√£o das hemiceluloses e a obten√ß√£o de XOS, minimizando a forma√ß√£o dos produtos de degrada√ß√£o com menor severidade de processo. Para o baga√ßo de cana-energia da Granbio, as condi√ß√Ķes estudadas sem catalisador mostraram uma convers√£o de xilana em XOS variando de 67,1 a 75,6%. Para a biomassa da Vignis, a convers√£o de xilana em XOS variou de 5,0 a 88,9%. Os XOS presentes no hidrolisado foram quantificados e caracterizados quanto ao grau de polimeriza√ß√£o. Os resultados obtidos mostraram que para o baga√ßo de cana-energia da Granbio, a condi√ß√£o otimizada (190¬įC, 15 min, 0[H2SO4]) gerou 8,6 g L-1 de XOS, enquanto para a variedade de cana-energia da Vignis, a condi√ß√£o otimizada (210¬įC, 5 min, 0 [H2SO4]) gerou 11,6 g L-1 de XOS. Devido √† presen√ßa de inibidores no hidrolisado, etapas de purifica√ß√£o podem ser necess√°rias, dependendo da aplica√ß√£o almejada para o produto. Com os dados obtidos neste estudo, √© poss√≠vel concluir que o pr√©-tratamento sequencial √© uma op√ß√£o vi√°vel para produ√ß√£o de XOS a partir da cana-energiaAbstract: The energy cane is a promising biomass¬Ņ source for studies of pretreatment stages, because it has high fiber content and low sucrose content, enabling the production of high added value products, as well as second generation ethanol. In this sense, the present work had as objective the evaluation of xylooligosaccharides (XOS) production from two energy cane varieties, using the optimization of a sequential pretreatment (deacetylation followed by hydrothermal pretreatment). The first step was to remove the acetyl groups attached to the hemicellulosic chain and the operational parameters such as time, temperature and sodium hydroxide concentration were studied. The results showed that the milder condition evaluated (15 min, 40¬ļC and 60 mgNaOH/gbiomass) promoted a solubilization of 74,3 ¬Ī 2,8% of acetyl groups for Granbio energy cane bagasse and 82,2 ¬Ī 1,8% for Vignis integral energy cane. In the second step, the hydrothermal pretreatment operating conditions were optimized using the optimized deacetylated material, in order to maximize the solubilization of the hemicelluloses and the XOS obtaining, minimizing the formation of degradation products with less process severity. For Granbio energy cane bagasse, the conditions studied without catalyst showed a conversion of xylan to XOS ranging from 67,1 to 75,6%. For the Vignis biomass, the conversion of xylan to XOS ranged from 5,0 to 88,9%. The XOS present in the hydrolyzate were quantified and characterized by the degree of polymerization. The results showed that for Granbio energy cane bagasse, the optimized condition (190¬įC, 15 min, 0 [H2SO4]) generated 8,6 g L-1 of XOS, whereas for the energy cane variety of Vignis, the optimized condition (210¬įC, 5 min, 0 [H2SO4]) generated 11,6 g L-1 of XOS. Due to the presence of inhibitors in the hydrolyzate, purification steps may be required, depending on the intended application of the product. With the data obtained in this study, it is possible to conclude that sequential pretreatment is a suitable option to produce XOS from energy caneMestradoEngenharia Qu√≠micaMestra em Engenharia Qu√≠mica151961/2015-8CNP

    Deep Underground Neutrino Experiment (DUNE) Near Detector Conceptual Design Report

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    International audienceThe Deep Underground Neutrino Experiment (DUNE) is an international, world-class experiment aimed at exploring fundamental questions about the universe that are at the forefront of astrophysics and particle physics research. DUNE will study questions pertaining to the preponderance of matter over antimatter in the early universe, the dynamics of supernovae, the subtleties of neutrino interaction physics, and a number of beyond the Standard Model topics accessible in a powerful neutrino beam. A critical component of the DUNE physics program involves the study of changes in a powerful beam of neutrinos, i.e., neutrino oscillations, as the neutrinos propagate a long distance. The experiment consists of a near detector, sited close to the source of the beam, and a far detector, sited along the beam at a large distance. This document, the DUNE Near Detector Conceptual Design Report (CDR), describes the design of the DUNE near detector and the science program that drives the design and technology choices. The goals and requirements underlying the design, along with projected performance are given. It serves as a starting point for a more detailed design that will be described in future documents

    The DUNE Far Detector Vertical Drift Technology, Technical Design Report

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    International audienceDUNE is an international experiment dedicated to addressing some of the questions at the forefront of particle physics and astrophysics, including the mystifying preponderance of matter over antimatter in the early universe. The dual-site experiment will employ an intense neutrino beam focused on a near and a far detector as it aims to determine the neutrino mass hierarchy and to make high-precision measurements of the PMNS matrix parameters, including the CP-violating phase. It will also stand ready to observe supernova neutrino bursts, and seeks to observe nucleon decay as a signature of a grand unified theory underlying the standard model. The DUNE far detector implements liquid argon time-projection chamber (LArTPC) technology, and combines the many tens-of-kiloton fiducial mass necessary for rare event searches with the sub-centimeter spatial resolution required to image those events with high precision. The addition of a photon detection system enhances physics capabilities for all DUNE physics drivers and opens prospects for further physics explorations. Given its size, the far detector will be implemented as a set of modules, with LArTPC designs that differ from one another as newer technologies arise. In the vertical drift LArTPC design, a horizontal cathode bisects the detector, creating two stacked drift volumes in which ionization charges drift towards anodes at either the top or bottom. The anodes are composed of perforated PCB layers with conductive strips, enabling reconstruction in 3D. Light-trap-style photon detection modules are placed both on the cryostat's side walls and on the central cathode where they are optically powered. This Technical Design Report describes in detail the technical implementations of each subsystem of this LArTPC that, together with the other far detector modules and the near detector, will enable DUNE to achieve its physics goals

    Reconstruction of interactions in the ProtoDUNE-SP detector with Pandora

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    International audienceThe Pandora Software Development Kit and algorithm libraries provide pattern-recognition logic essential to the reconstruction of particle interactions in liquid argon time projection chamber detectors. Pandora is the primary event reconstruction software used at ProtoDUNE-SP, a prototype for the Deep Underground Neutrino Experiment far detector. ProtoDUNE-SP, located at CERN, is exposed to a charged-particle test beam. This paper gives an overview of the Pandora reconstruction algorithms and how they have been tailored for use at ProtoDUNE-SP. In complex events with numerous cosmic-ray and beam background particles, the simulated reconstruction and identification efficiency for triggered test-beam particles is above 80% for the majority of particle type and beam momentum combinations. Specifically, simulated 1 GeV/cc charged pions and protons are correctly reconstructed and identified with efficiencies of 86.1¬Ī0.6\pm0.6% and 84.1¬Ī0.6\pm0.6%, respectively. The efficiencies measured for test-beam data are shown to be within 5% of those predicted by the simulation

    Reconstruction of interactions in the ProtoDUNE-SP detector with Pandora