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

Orientadores: Telma Teixeira Franco, Sarita Cândida RabeloDissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia QuímicaResumo: A cana-energia é uma fonte de biomassa promissora para estudos de etapas de pré-tratamento, pois possui alto teor de fibras e baixo teor de sacarose, possibilitando a produção de produtos de alto valor agregado, além de etanol de segunda geração. Neste sentido, o presente trabalho teve como objetivo avaliar a produção de xilooligossacarídeos (XOS) a partir de duas variedades de cana-energia, empregando a otimização de um pré-tratamento sequencial (desacetilação seguida por pré-tratamento hidrotérmico). A primeira etapa teve como objetivo remover os grupos acetila ligados à cadeia hemicelulósica sendo estudados os parâmetros operacionais como tempo, temperatura e concentração de hidróxido de sódio. Os resultados mostraram que a condição mais branda avaliada (15 min, 40°C e 60 mgNaOH/gbiomassa) promoveu uma solubilização de 74,3 ± 2,8% de grupos acetila para o bagaço de cana-energia da empresa Granbio e 82,2 ± 1,8% para a cana-energia integral da empresa Vignis. Na segunda etapa, as condições operacionais do pré-tratamento hidrotérmico foram otimizadas utilizando o material desacetilado otimizado, com o intuito de maximizar a solubilização das hemiceluloses e a obtenção de XOS, minimizando a formação dos produtos de degradação com menor severidade de processo. Para o bagaço de cana-energia da Granbio, as condições estudadas sem catalisador mostraram uma conversão de xilana em XOS variando de 67,1 a 75,6%. Para a biomassa da Vignis, a conversão de xilana em XOS variou de 5,0 a 88,9%. Os XOS presentes no hidrolisado foram quantificados e caracterizados quanto ao grau de polimerização. Os resultados obtidos mostraram que para o bagaço de cana-energia da Granbio, a condição otimizada (190°C, 15 min, 0[H2SO4]) gerou 8,6 g L-1 de XOS, enquanto para a variedade de cana-energia da Vignis, a condição otimizada (210°C, 5 min, 0 [H2SO4]) gerou 11,6 g L-1 de XOS. Devido à presença de inibidores no hidrolisado, etapas de purificação podem ser necessárias, dependendo da aplicação almejada para o produto. Com os dados obtidos neste estudo, é possível concluir que o pré-tratamento sequencial é uma opção viável para produção de XOS a partir da cana-energiaAbstract: The energy cane is a promising biomass¿ 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, 40ºC and 60 mgNaOH/gbiomass) promoted a solubilization of 74,3 ± 2,8% of acetyl groups for Granbio energy cane bagasse and 82,2 ± 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°C, 15 min, 0 [H2SO4]) generated 8,6 g L-1 of XOS, whereas for the energy cane variety of Vignis, the optimized condition (210°C, 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 QuímicaMestra em Engenharia Química151961/2015-8CNP

Surface Acoustic Wave Humidity Sensors Based on Graphene Oxide Thin Films Deposited with the Surface Acoustic Wave Atomizer

Submicron-thick films of graphene oxide and polyvinyl alcohol (PVA) were deposited onto the surface of 160 MHz quartz surface acoustic wave (SAW) delay lines, and manufactured devices were used as humidity sensors. Films were obtained by consecutive atomization of 0.35 μl droplets of 0.33 mg/ml graphene oxide water suspension or 5.00 mg/ml PVA water solution using 25 MHz SAW atomizers. During measurements authors did not observe additional attenuation of the surface acoustic wave propagating along the surface of the sensors, which confirms that deposited films have low thickness and good uniformity. It was shown that SAW quartz humidity sensors with graphene oxide films, PVA thin films and uncoated surface have sensitivity of 1.54 kHz/%RH, 0.47 kHz/%RH and 0.13 kHz/%RH respectively. Sensors with graphene oxide thin films showed the best sensitivity and dynamic response. It was concluded that they can be used as sensitive coatings in humidity sensors for industrial environment.</jats:p

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

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

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

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/$c$ charged pions and protons are correctly reconstructed and identified with efficiencies of 86.1$\pm0.6$% and 84.1$\pm0.6$%, respectively. The efficiencies measured for test-beam data are shown to be within 5% of those predicted by the simulation

The DUNE Phase II Detectors

International audienceThe international collaboration designing and constructing the Deep Underground Neutrino Experiment (DUNE) at the Long-Baseline Neutrino Facility (LBNF) has developed a two-phase strategy for the implementation of this leading-edge, large-scale science project. The 2023 report of the US Particle Physics Project Prioritization Panel (P5) reaffirmed this vision and strongly endorsed DUNE Phase I and Phase II, as did the previous European Strategy for Particle Physics. The construction of DUNE Phase I is well underway. DUNE Phase II consists of a third and fourth far detector module, an upgraded near detector complex, and an enhanced > 2 MW beam. The fourth FD module is conceived as a 'Module of Opportunity', aimed at supporting the core DUNE science program while also expanding the physics opportunities with more advanced technologies. The DUNE collaboration is submitting four main contributions to the 2026 Update of the European Strategy for Particle Physics process. This submission to the 'Detector instrumentation' stream focuses on technologies and R&D for the DUNE Phase II detectors. Additional inputs related to the DUNE science program, DUNE software and computing, and European contributions to Fermilab accelerator upgrades and facilities for the DUNE experiment, are also being submitted to other streams

European Contributions to Fermilab Accelerator Upgrades and Facilities for the DUNE Experiment

International audienceThe Proton Improvement Plan (PIP-II) to the FNAL accelerator chain and the Long-Baseline Neutrino Facility (LBNF) will provide the world's most intense neutrino beam to the Deep Underground Neutrino Experiment (DUNE) enabling a wide-ranging physics program. This document outlines the significant contributions made by European national laboratories and institutes towards realizing the first phase of the project with a 1.2 MW neutrino beam. Construction of this first phase is well underway. For DUNE Phase II, this will be closely followed by an upgrade of the beam power to > 2 MW, for which the European groups again have a key role and which will require the continued support of the European community for machine aspects of neutrino physics. Beyond the neutrino beam aspects, LBNF is also responsible for providing unique infrastructure to install and operate the DUNE neutrino detectors at FNAL and at the Sanford Underground Research Facility (SURF). The cryostats for the first two Liquid Argon Time Projection Chamber detector modules at SURF, a contribution of CERN to LBNF, are central to the success of the ongoing execution of DUNE Phase I. Likewise, successful and timely procurement of cryostats for two additional detector modules at SURF will be critical to the success of DUNE Phase II and the overall physics program. The DUNE Collaboration is submitting four main contributions to the 2026 Update of the European Strategy for Particle Physics process. This paper is being submitted to the 'Accelerator technologies' and 'Projects and Large Experiments' streams. Additional inputs related to the DUNE science program, DUNE detector technologies and R&D, and DUNE software and computing, are also being submitted to other streams

Neutrino Interaction Vertex Reconstruction in DUNE with Pandora Deep Learning

International audienceThe Pandora Software Development Kit and algorithm libraries perform reconstruction of neutrino interactions in liquid argon time projection chamber detectors. Pandora is the primary event reconstruction software used at the Deep Underground Neutrino Experiment, which will operate four large-scale liquid argon time projection chambers at the far detector site in South Dakota, producing high-resolution images of charged particles emerging from neutrino interactions. While these high-resolution images provide excellent opportunities for physics, the complex topologies require sophisticated pattern recognition capabilities to interpret signals from the detectors as physically meaningful objects that form the inputs to physics analyses. A critical component is the identification of the neutrino interaction vertex. Subsequent reconstruction algorithms use this location to identify the individual primary particles and ensure they each result in a separate reconstructed particle. A new vertex-finding procedure described in this article integrates a U-ResNet neural network performing hit-level classification into the multi-algorithm approach used by Pandora to identify the neutrino interaction vertex. The machine learning solution is seamlessly integrated into a chain of pattern-recognition algorithms. The technique substantially outperforms the previous BDT-based solution, with a more than 20% increase in the efficiency of sub-1 cm vertex reconstruction across all neutrino flavours