43 research outputs found

    Bioethanol production from autohydrolyzed Sargassum muticum

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    Currently, the high demand of energy has led to the seek of new renewable sources, cutting down with fossil fuels. An interesting and novel way may be the use of macoralgae as raw material to obtain third generation bioethanol. Sargassum muticum is an invasive seaweed highly spread in Asia, Europe and America, which has not been commercially used yet. It has an abundant quantity of polysaccharides which can be used in the production of biofuels. In order to employ them, it is necessary to pretreat the material, and the hydrothermal treatments (as autohydrolysis) have demonstrated to be highly effective, simple, environmentally friendly and economic. In this work, the study of the autohydrolysis of Sargassum muticum has been studied. Consequently, Simultaneous Saccharification and Fermentation took place, using different industrial strains of Saccharomyces cerevisiae and two type of experiments: i) using only the autohydrolyzed solid phase, ii) using the liquid and solid phase from the autohydrolysis procedure.info:eu-repo/semantics/publishedVersio

    Enhancement of the enzymatic hydrolysis of Paulownia wood using non-ionic surfactant

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    The abundance of lignocellulosic biomass from various industries provides a great potential feedstock for the production of value-added products. This lignocellulosic materials can be enzymatically hydrolyzed into sugars for the production of biofuels and biomaterials. However, the presence of lignin is inhibitory, becoming a major obstacle for enzymatic hydrolysis of lignocellulosic materials conducted in high solid loading. This is because the lignin acts as a protective barrier for cellulose and, thus, restricts the accessibility of the enzyme to the cellulose. Addition of surfactants, polymers, and noncatalytic proteins can improve the enzymatic hydrolysis of lignocellulosic materials by blocking the exposed lignin surfaces. In this work, the optimization of enzymatic hydrolysis of Paulownia wood was tested, evaluating the influence of: i) autohydrolysis pretreatment under non-isothermal conditions (TMAX: 210ºC, 220ºC and 230ºC), ii) solid loading (Consistency: 10, 13 and 16 %), iii) enzyme substrate ratio (ESR: 8, 12 and 16 UPF/g Paulownia), and iv) the addition of nonionic surfactant Tween 20 (0, 1.5 and 3 g/L). The enzyme employed was Cellic CTec2 (Novozymes) with an enzyme activity of 160 UFP/mL. This work suggested that autohydrolysis pretreatment could improve the enzymatic hydrolysis significantly and the addition of Tween 20 could reduce the hydrolysis time and enzyme dosage.info:eu-repo/semantics/publishedVersio

    Restauración de las olmedas ibéricas (Ulmus minor y U. laevis) en zonas riparias de la Comunidad de Madrid

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    El proyecto LIFE+ “Olmos Vivos” (LIFE13 BIO/ES/000556) tiene como objetivo la restauración de unas formaciones vegetales, las olmedas, que por diversos motivos prácticamente han desaparecido del paisaje forestal español, a pesar de haber poseído un alto valor ecológico y cultural. La grafiosis ha constituido una de las enfermedades forestales más devastadoras, y supuso la práctica desaparición de las olmedas ibéricas de Ulmus minor . En el caso de Ulmus laevis , la alteración de su hábitat ligado a zonas temporalmente encharcadas y riberas ha provocado que las poblaciones españolas se encuentren en riesgo de desaparición. Gracias a la obtención de siete clones de U. minor resistentes a la grafiosis como fruto del Programa del Olmo (UPM-MAGRAMA), el presente proyecto permitirá reintroducir la especie en diversas localizaciones de ribera de los ríos Jarama y Tajo. Asimismo, se plantarán brinzales obtenidos de agrupaciones relícticas de U. laevis , con el fin de aumentar sus poblaciones y conservar sus recursos genéticos, en terrenos de naturaleza silícea de las riberas del río Jarama y Arroyo Viñuelas. El desarrollo del proyecto, de cinco años y tres meses de duración 2014-2019), prevé la plantación de unas 16 700 plantas. Al mismo tiempo se recuperará en nuestras ciudades y pueblos la presencia del olmo, mediante plantaciones con fines divulgativos en entornos urbanos y paseos históricos, para devolver así el protagonismo cultural a un árbol que siempre estuvo entre nosotros, presidiendo las reuniones en las plazas y acompañando con su sombra en muchos caminos de nuestra geografía

    Dark Matter and Fundamental Physics with the Cherenkov Telescope Array

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    The Cherenkov Telescope Array (CTA) is a project for a next-generation observatory for very high energy (GeV-TeV) ground-based gamma-ray astronomy, currently in its design phase, and foreseen to be operative a few years from now. Several tens of telescopes of 2-3 different sizes, distributed over a large area, will allow for a sensitivity about a factor 10 better than current instruments such as H.E.S.S, MAGIC and VERITAS, an energy coverage from a few tens of GeV to several tens of TeV, and a field of view of up to 10 deg. In the following study, we investigate the prospects for CTA to study several science questions that influence our current knowledge of fundamental physics. Based on conservative assumptions for the performance of the different CTA telescope configurations, we employ a Monte Carlo based approach to evaluate the prospects for detection. First, we discuss CTA prospects for cold dark matter searches, following different observational strategies: in dwarf satellite galaxies of the Milky Way, in the region close to the Galactic Centre, and in clusters of galaxies. The possible search for spatial signatures, facilitated by the larger field of view of CTA, is also discussed. Next we consider searches for axion-like particles which, besides being possible candidates for dark matter may also explain the unexpectedly low absorption by extragalactic background light of gamma rays from very distant blazars. Simulated light-curves of flaring sources are also used to determine the sensitivity to violations of Lorentz Invariance by detection of the possible delay between the arrival times of photons at different energies. Finally, we mention searches for other exotic physics with CTA.Comment: (31 pages, Accepted for publication in Astroparticle Physics

    The 2010 very high energy gamma-ray flare & 10 years of multi-wavelength observations of M 87

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    Abridged: The giant radio galaxy M 87 with its proximity, famous jet, and very massive black hole provides a unique opportunity to investigate the origin of very high energy (VHE; E>100 GeV) gamma-ray emission generated in relativistic outflows and the surroundings of super-massive black holes. M 87 has been established as a VHE gamma-ray emitter since 2006. The VHE gamma-ray emission displays strong variability on timescales as short as a day. In this paper, results from a joint VHE monitoring campaign on M 87 by the MAGIC and VERITAS instruments in 2010 are reported. During the campaign, a flare at VHE was detected triggering further observations at VHE (H.E.S.S.), X-rays (Chandra), and radio (43 GHz VLBA). The excellent sampling of the VHE gamma-ray light curve enables one to derive a precise temporal characterization of the flare: the single, isolated flare is well described by a two-sided exponential function with significantly different flux rise and decay times. While the overall variability pattern of the 2010 flare appears somewhat different from that of previous VHE flares in 2005 and 2008, they share very similar timescales (~day), peak fluxes (Phi(>0.35 TeV) ~= (1-3) x 10^-11 ph cm^-2 s^-1), and VHE spectra. 43 GHz VLBA radio observations of the inner jet regions indicate no enhanced flux in 2010 in contrast to observations in 2008, where an increase of the radio flux of the innermost core regions coincided with a VHE flare. On the other hand, Chandra X-ray observations taken ~3 days after the peak of the VHE gamma-ray emission reveal an enhanced flux from the core. The long-term (2001-2010) multi-wavelength light curve of M 87, spanning from radio to VHE and including data from HST, LT, VLA and EVN, is used to further investigate the origin of the VHE gamma-ray emission. No unique, common MWL signature of the three VHE flares has been identified.Comment: 19 pages, 5 figures; Corresponding authors: M. Raue, L. Stawarz, D. Mazin, P. Colin, C. M. Hui, M. Beilicke; Fig. 1 lightcurve data available online: http://www.desy.de/~mraue/m87

    Sensitivity of the Cherenkov Telescope Array to a dark matter signal from the Galactic centre

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    We provide an updated assessment of the power of the Cherenkov Telescope Array (CTA) to search for thermally produced dark matter at the TeV scale, via the associated gamma-ray signal from pair-annihilating dark matter particles in the region around the Galactic centre. We find that CTA will open a new window of discovery potential, significantly extending the range of robustly testable models given a standard cuspy profile of the dark matter density distribution. Importantly, even for a cored profile, the projected sensitivity of CTA will be sufficient to probe various well-motivated models of thermally produced dark matter at the TeV scale. This is due to CTA's unprecedented sensitivity, angular and energy resolutions, and the planned observational strategy. The survey of the inner Galaxy will cover a much larger region than corresponding previous observational campaigns with imaging atmospheric Cherenkov telescopes. CTA will map with unprecedented precision the large-scale diffuse emission in high-energy gamma rays, constituting a background for dark matter searches for which we adopt state-of-the-art models based on current data. Throughout our analysis, we use up-to-date event reconstruction Monte Carlo tools developed by the CTA consortium, and pay special attention to quantifying the level of instrumental systematic uncertainties, as well as background template systematic errors, required to probe thermally produced dark matter at these energies.</p

    Sensitivity of the Cherenkov Telescope Array for probing cosmology and fundamental physics with gamma-ray propagation

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    The Cherenkov Telescope Array (CTA), the new-generation ground-based observatory for γ\gamma-ray astronomy, provides unique capabilities to address significant open questions in astrophysics, cosmology, and fundamental physics. We study some of the salient areas of γ\gamma-ray cosmology that can be explored as part of the Key Science Projects of CTA, through simulated observations of active galactic nuclei (AGN) and of their relativistic jets. Observations of AGN with CTA will enable a measurement of γ\gamma-ray absorption on the extragalactic background light with a statistical uncertainty below 15% up to a redshift z=2z=2 and to constrain or detect γ\gamma-ray halos up to intergalactic-magnetic-field strengths of at least 0.3pG. Extragalactic observations with CTA also show promising potential to probe physics beyond the Standard Model. The best limits on Lorentz invariance violation from γ\gamma-ray astronomy will be improved by a factor of at least two to three. CTA will also probe the parameter space in which axion-like particles could constitute a significant fraction, if not all, of dark matter. We conclude on the synergies between CTA and other upcoming facilities that will foster the growth of γ\gamma-ray cosmology

    Risk profiles and one-year outcomes of patients with newly diagnosed atrial fibrillation in India: Insights from the GARFIELD-AF Registry.

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    BACKGROUND: The Global Anticoagulant Registry in the FIELD-Atrial Fibrillation (GARFIELD-AF) is an ongoing prospective noninterventional registry, which is providing important information on the baseline characteristics, treatment patterns, and 1-year outcomes in patients with newly diagnosed non-valvular atrial fibrillation (NVAF). This report describes data from Indian patients recruited in this registry. METHODS AND RESULTS: A total of 52,014 patients with newly diagnosed AF were enrolled globally; of these, 1388 patients were recruited from 26 sites within India (2012-2016). In India, the mean age was 65.8 years at diagnosis of NVAF. Hypertension was the most prevalent risk factor for AF, present in 68.5% of patients from India and in 76.3% of patients globally (P < 0.001). Diabetes and coronary artery disease (CAD) were prevalent in 36.2% and 28.1% of patients as compared with global prevalence of 22.2% and 21.6%, respectively (P < 0.001 for both). Antiplatelet therapy was the most common antithrombotic treatment in India. With increasing stroke risk, however, patients were more likely to receive oral anticoagulant therapy [mainly vitamin K antagonist (VKA)], but average international normalized ratio (INR) was lower among Indian patients [median INR value 1.6 (interquartile range {IQR}: 1.3-2.3) versus 2.3 (IQR 1.8-2.8) (P < 0.001)]. Compared with other countries, patients from India had markedly higher rates of all-cause mortality [7.68 per 100 person-years (95% confidence interval 6.32-9.35) vs 4.34 (4.16-4.53), P < 0.0001], while rates of stroke/systemic embolism and major bleeding were lower after 1 year of follow-up. CONCLUSION: Compared to previously published registries from India, the GARFIELD-AF registry describes clinical profiles and outcomes in Indian patients with AF of a different etiology. The registry data show that compared to the rest of the world, Indian AF patients are younger in age and have more diabetes and CAD. Patients with a higher stroke risk are more likely to receive anticoagulation therapy with VKA but are underdosed compared with the global average in the GARFIELD-AF. CLINICAL TRIAL REGISTRATION-URL: http://www.clinicaltrials.gov. Unique identifier: NCT01090362

    Sensitivity of the Cherenkov Telescope Array for probing cosmology and fundamental physics with gamma-ray propagation

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    The Cherenkov Telescope Array (CTA), the new-generation ground-based observatory for γ astronomy, provides unique capabilities to address significant open questions in astrophysics, cosmology, and fundamental physics. We study some of the salient areas of γ cosmology that can be explored as part of the Key Science Projects of CTA, through simulated observations of active galactic nuclei (AGN) and of their relativistic jets. Observations of AGN with CTA will enable a measurement of γ absorption on the extragalactic background light with a statistical uncertainty below 15% up to a redshift z=2 and to constrain or detect γ halos up to intergalactic-magnetic-field strengths of at least 0.3 pG . Extragalactic observations with CTA also show promising potential to probe physics beyond the Standard Model. The best limits on Lorentz invariance violation from γ astronomy will be improved by a factor of at least two to three. CTA will also probe the parameter space in which axion-like particles could constitute a significant fraction, if not all, of dark matter. We conclude on the synergies between CTA and other upcoming facilities that will foster the growth of γ cosmology.</p
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