387 research outputs found

    Exploring the potential of conventional and flash pyrolysis methods for the valorisation of grape seed and chestnut shell biomass from agri-food industry waste

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    Producción CientíficaResidual biomass is a valuable and growing by-product, but often underutilized. This research aims to investigate the possible strategies for the energetic valorisation of agri-food industry wastes: grape seed and chestnut shell. Pyrolysis thermal process was the selected for this work. Applied to biomass, pyrolysis is a promising method for the simultaneous production of biochar, bio-oil, and gas. Two different pyrolysis processes were conducted: conventional pyrolysis at 750 °C and flash pyrolysis at 750 °C and 850 °C. Flash pyrolysis yielded superior product properties compared to conventional pyrolysis. The gas obtained through flash pyrolysis presented a four-fold higher high heating value due to increased CH4 and H2 content. Bio-oil contains over 90% of polycyclic aromatic hydrocarbons, and calorific value reached up to 32 MJ kg−1 for grape seed, which is 7% more than bioethanol HHV. Biochar can be used both as fuel or as activated carbon precursor due to its high carbon content (91%). Calorific value of chestnut shell biochar (32.7 MJ kg−1), comparable to mineral coals, increased by 72% with respect to the value of this untreated raw material. This work approved the potential of flash pyrolysis as a method to process biomass wastes in a renewable energy scenario.FICYT - Fundación Fomento Asturias Investigación - FEDER (AYUD/2021/51379)Agencia Española de Investigación (PDC2022-133394-I00 y PID2021-124347OB-I00

    Identifying new potential areas for the establishment of the invasive raccoon (Procyon lotor) in Europe

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    The concern about biological invasions is growing worldwide because implies a serious threat to biodiversity conservation, the high economic costs of management measures and, in many cases, involves a health risk for humans, since some species are host of pathogens that are transmitted to humans. The raccoon (Procyon lotor), a medium-size carnivore native from North America, is a good example of invasive species. Its high ecological plasticity has allowed it to adapt successfully to different ecosystems in Europe and Asia, where the species has been introduced due to: releases for hunting, fur farms escapes and more recently the pet trade. The successful raccoon’s expansion in Europe poses a threat to biodiversity conservation. In this study we review and update the distribution of this species in Europe, with the aim of identifying new potential areas for the establishment of the raccoon in Europe. According to this updating of presences and a set of predictors variables (environmental and human activity), we applied the Favourability Function to detect favourable areas for the species. Anthropic variables have a significant relevance explaining the current occurrence of this invasive species. The favourability model detected central Europe and the United Kingdom as the areas with the best conditions for the species, being related to territories with a high percentage of urban area. This may indicate that the invasion pattern could still be reflecting the places of releases. In this sense, the favourable areas for the presence of the raccoon highlight unoccupied zones with high potential to be established in the near future. Our results provide useful information to increase the monitoring effort and develop prevention plans to optimize effective control measuresUniversidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Profibrotic role of inducible heat shock protein 90α isoform in systemic sclerosis

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    Systemic sclerosis (SSc) is an autoimmune disease that affects skin and multiple internal organs. TGF-β, a central trigger of cutaneous fibrosis, activates fibroblasts with the involvement of the stress-inducible chaperone heat shock protein 90 isoform α (Hsp90α). Available evidence supports overexpression and secretion of Hsp90α as a feature in profibrotic pathological conditions. The aim of this work is to investigate the expression and function of Hsp90α in experimental models of skin fibrosis such as human fibroblasts, C57BL/6 mice, and in human SSc. For this purpose, we generated a new experimental model based on doxorubicin administration with improved characteristics with respect to the bleomycin model. We visualized disease progression in vivo by fluorescence imaging. In this work, we obtained Hsp90α mRNA overexpression in human skin fibroblasts, in bleomycin- and doxorubicin-induced mouse fibrotic skin, and in lungs of bleomycin- and doxorubicin-treated mice. Hsp90α-deficient mice showed significantly decreased skin thickness compared with wild-type mice in both animal models. In SSc patients, serum Hsp90α levels were increased in patients with lung involvement and in patients with the diffuse form of SSc (dSSc) compared with patients with the limited form of SSc. The serum Hsp90α levels of patients dSSc were correlated with the Rodnan score and the forced vital capacity variable. These results provide new supportive evidence of the contribution of the Hsp90α isoform in the development of skin fibrosis. In SSc, these results indicated that higher serum levels were associated with dSSc and lung fibrosis.This work was supported by Spanish Ministerio de Economía, Industria y Competitividad, Gobierno de España Grant RTI2018-095214-B-I00, as well as by the Instituto de Formación e Investigación Marqués de Valdecilla IDIVAL (InnVal 17/22; InnVal 20/34), 2020UCI22-PUB-0003 Gobierno de Cantabria (to A.V.V.), SAF2016-75195-R (to J.M.), SAF2017-82905-R (to R.M.), and (NextVal 18/14) to A.P

    Relationship of runoff, erosion and sediment yield to weather types in the Iberian Peninsula

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    Precipitation has been recognized as one of the main factors driving soil erosion and sediment yield (SY), and its spatial and temporal variability is recognized as one of themain reasons for spatial and temporal analyses of soil erosion variability. The weather types (WTs) approach classifies the continuumof atmospheric circulation into a small number of categories or types and has been proven a good indicator of the spatial and temporal variability of precipitation. Thus, themain objective of this study is to analyze the relationship betweenWTs, runoff, soil erosion (measured in plots), and sediment yield (measured in catchments) in different areas of the Iberian Peninsula (IP) with the aimof detecting spatial variations in these relationships. To this end, hydrological and sediment information covering the IP from several Spanish research teams has been combined, and related with daily WTs estimated by using the NMC/NCAR 40-Year Reanalysis Project. The results showthat, in general, a fewWTs (particularly westerly, southwesterly and cyclonic) provide the largest amounts of precipitation; and southwesterly, northwesterly and westerly WTs play an important role in runoff generation, erosion and sediment yield as they coincide with the wettest WTs. However, this study highlights the spatial variability of erosion and sediment yield in the IP according to WT, differentiating (1) areas under the influence of north and/or north-westerly flows (the north coast of Cantabria and inland central areas), (2) areas under the influence of westerly, southwesterly and cyclonic WTs (western and southwestern IP), (3) areas in which erosion and sediment yield are controlled by easterly flows (Mediterranean coastland), and (4) lastly, a transitional zone in the inland northeast Ebro catchment,wherewe detected a high variability in the effects ofWTs on erosion. Overall results suggest that the use of WTs derived fromobserved atmospheric pressure patterns could be a useful tool for inclusion in future projections of the spatial variability of erosion and sediment yield, as models capture pressure fields reliably

    VAMOS: a Pathfinder for the HAWC Gamma-Ray Observatory

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    VAMOS was a prototype detector built in 2011 at an altitude of 4100m a.s.l. in the state of Puebla, Mexico. The aim of VAMOS was to finalize the design, construction techniques and data acquisition system of the HAWC observatory. HAWC is an air-shower array currently under construction at the same site of VAMOS with the purpose to study the TeV sky. The VAMOS setup included six water Cherenkov detectors and two different data acquisition systems. It was in operation between October 2011 and May 2012 with an average live time of 30%. Besides the scientific verification purposes, the eight months of data were used to obtain the results presented in this paper: the detector response to the Forbush decrease of March 2012, and the analysis of possible emission, at energies above 30 GeV, for long gamma-ray bursts GRB111016B and GRB120328B.Comment: Accepted for pubblication in Astroparticle Physics Journal (20 pages, 10 figures). Corresponding authors: A.Marinelli and D.Zaboro

    All-particle cosmic ray energy spectrum measured by the HAWC experiment from 10 to 500 TeV

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    We report on the measurement of the all-particle cosmic ray energy spectrum with the High Altitude Water Cherenkov (HAWC) Observatory in the energy range 10 to 500 TeV. HAWC is a ground based air-shower array deployed on the slopes of Volcan Sierra Negra in the state of Puebla, Mexico, and is sensitive to gamma rays and cosmic rays at TeV energies. The data used in this work were taken from 234 days between June 2016 to February 2017. The primary cosmic-ray energy is determined with a maximum likelihood approach using the particle density as a function of distance to the shower core. Introducing quality cuts to isolate events with shower cores landing on the array, the reconstructed energy distribution is unfolded iteratively. The measured all-particle spectrum is consistent with a broken power law with an index of 2.49±0.01-2.49\pm0.01 prior to a break at (45.7±0.1(45.7\pm0.1) TeV, followed by an index of 2.71±0.01-2.71\pm0.01. The spectrum also respresents a single measurement that spans the energy range between direct detection and ground based experiments. As a verification of the detector response, the energy scale and angular resolution are validated by observation of the cosmic ray Moon shadow's dependence on energy.Comment: 16 pages, 11 figures, 4 tables, submission to Physical Review

    Constraining the pˉ/p\bar{p}/p Ratio in TeV Cosmic Rays with Observations of the Moon Shadow by HAWC

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    An indirect measurement of the antiproton flux in cosmic rays is possible as the particles undergo deflection by the geomagnetic field. This effect can be measured by studying the deficit in the flux, or shadow, created by the Moon as it absorbs cosmic rays that are headed towards the Earth. The shadow is displaced from the actual position of the Moon due to geomagnetic deflection, which is a function of the energy and charge of the cosmic rays. The displacement provides a natural tool for momentum/charge discrimination that can be used to study the composition of cosmic rays. Using 33 months of data comprising more than 80 billion cosmic rays measured by the High Altitude Water Cherenkov (HAWC) observatory, we have analyzed the Moon shadow to search for TeV antiprotons in cosmic rays. We present our first upper limits on the pˉ/p\bar{p}/p fraction, which in the absence of any direct measurements, provide the tightest available constraints of 1%\sim1\% on the antiproton fraction for energies between 1 and 10 TeV.Comment: 10 pages, 5 figures. Accepted by Physical Review

    Very high energy particle acceleration powered by the jets of the microquasar SS 433

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    SS 433 is a binary system containing a supergiant star that is overflowing its Roche lobe with matter accreting onto a compact object (either a black hole or neutron star). Two jets of ionized matter with a bulk velocity of 0.26c\sim0.26c extend from the binary, perpendicular to the line of sight, and terminate inside W50, a supernova remnant that is being distorted by the jets. SS 433 differs from other microquasars in that the accretion is believed to be super-Eddington, and the luminosity of the system is 1040\sim10^{40} erg s1^{-1}. The lobes of W50 in which the jets terminate, about 40 pc from the central source, are expected to accelerate charged particles, and indeed radio and X-ray emission consistent with electron synchrotron emission in a magnetic field have been observed. At higher energies (>100 GeV), the particle fluxes of γ\gamma rays from X-ray hotspots around SS 433 have been reported as flux upper limits. In this energy regime, it has been unclear whether the emission is dominated by electrons that are interacting with photons from the cosmic microwave background through inverse-Compton scattering or by protons interacting with the ambient gas. Here we report TeV γ\gamma-ray observations of the SS 433/W50 system where the lobes are spatially resolved. The TeV emission is localized to structures in the lobes, far from the center of the system where the jets are formed. We have measured photon energies of at least 25 TeV, and these are certainly not Doppler boosted, because of the viewing geometry. We conclude that the emission from radio to TeV energies is consistent with a single population of electrons with energies extending to at least hundreds of TeV in a magnetic field of 16\sim16~micro-Gauss.Comment: Preprint version of Nature paper. Contacts: S. BenZvi, B. Dingus, K. Fang, C.D. Rho , H. Zhang, H. Zho
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