2,567 research outputs found

    Catalyst- and solvent-free synthesis of 2-fluoro-N- (3-methylsulfanyl-1H-1,2,4-triazol-5-yl)benzamide through a microwave-assisted Fries rearrangement : X-ray structural and theoretical studies

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    An efficient approach for the regioselective synthesis of (5-amino-3-methylsulfanyl- 1H-1,2,4-triazol-1-yl)(2-fluorophenyl)methanone, C10H9FN4OS, (3), from the N-acylation of 3-amino-5-methylsulfanyl-1H-1,2,4-triazole, (1), with 2-fluorobenzoyl chloride has been developed. Heterocyclic amide (3) was used successfully as a strategic intermediate for the preparation of 2-fluoro-N-(3- methylsulfanyl-1H-1,2,4-triazol-5-yl)benzamide, C10H9FN4OS, (4), through a microwave-assisted Fries rearrangement under catalyst- and solvent-free conditions. Theoretical studies of the prototropy process of (1) and the Fries rearrangement of (3) to provide (4), involving the formation of an intimate ion pair as the key step, were carried out by density functional theory (DFT) calculations. The crystallographic analysis of the intermolecular interactions and the energy frameworks based on the effects of the different molecular conformations of (3) and (4) are described

    Preventive Conservation and Restoration Monitoring of Heritage Buildings Based on Fuzzy Logic

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    This article discusses the usability of the Art-Risk 3.0 software for research on the conservation of heritage buildings. It is a new and free software based on fuzzy logic, which enables the assessment of preventive conservation and surveillance of the restoration of heritage buildings over a period of time. This artificial intelligence-based tool considers the vulnerability of buildings, their environ ments, and their management to evaluate the necessity of their restoration or preventive con servation. To validate the Art-Risk 3.0, 500 theoretical case studies were analyzed, and a 14th century Mudejar-Gothic-style Church in Seville, Spain was studied both before and after its restora tion to identify post-restoration changes. This proof of concept demonstrates the capability of the Art-Risk 3.0 software to analyze environmental impacts on the vulnerability, risk, and functional service life of buildings, and assess the effectiveness of restoration activities. Additionally, this software identifies the most problematic factors and the necessity of restoration.Ministerio de Economía y Competitividad BIA2015- 64878-R (RETOS)Ministerio de Ciencia e Innovación PID2019-107257RB-I00 (FENIX)Ministerio de Ciencia, Innovación y Universidades EQC2019-005780-P (Ambulab-LAB)Junta de Andalucía PYC20 RE 034 UPO RESILIENT-TOURISMMinisterio de Ciencia e Innovación PTA2019-01688

    Removal of nutrients and pesticides from agricultural runoff using microalgae and cyanobacteria

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    The use of pesticides in agriculture has ensured the production of different crops. However, pesticides have become an emerging public health problem for Latin American countries due to their excessive use, inadequate application, toxic characteristics, and minimal residue control. The current project evaluates the ability of two strains of algae (Chlorella and Scenedesmus sp.) and one cyanobacteria (Hapalosyphon sp.) to remove excess pesticides and other nutrients present in runoff water from rice production. Different concentrations of wastewater and carbon sources (Na2CO3 and NaHCO3 ) were evaluated. According to the results, all three strains can be grown in wastewater without dilution (100%), with a biomass concentration comparable to a synthetic medium. All three strains significantly reduced the concentration of NO3 and PO4 (95 and 85%, respectively), with no difference between Na2CO3 or NaHCO3 . Finally, Chlorella sp. obtained the highest removal efficiency of the pesticide (Chlorpyrifos), followed by Scenedesmus and Hapalosyphon sp. (100, 75, and 50%, respectively). This work shows that it is possible to use this type of waste as an alternative source of nutrients to obtain biomass and metabolites of interest, such as lipids and carbohydrates, to produce biofuels

    The Sensitivity of HAWC to High-Mass Dark Matter Annihilations

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    The High Altitude Water Cherenkov (HAWC) observatory is a wide field-of-view detector sensitive to gamma rays of 100 GeV to a few hundred TeV. Located in central Mexico at 19 degrees North latitude and 4100 m above sea level, HAWC will observe gamma rays and cosmic rays with an array of water Cherenkov detectors. The full HAWC array is scheduled to be operational in Spring 2015. In this paper, we study the HAWC sensitivity to the gamma-ray signatures of high-mass (multi- TeV) dark matter annihilation. The HAWC observatory will be sensitive to diverse searches for dark matter annihilation, including annihilation from extended dark matter sources, the diffuse gamma-ray emission from dark matter annihilation, and gamma-ray emission from non-luminous dark matter subhalos. Here we consider the HAWC sensitivity to a subset of these sources, including dwarf galaxies, the M31 galaxy, the Virgo cluster, and the Galactic center. We simulate the HAWC response to gamma rays from these sources in several well-motivated dark matter annihilation channels. If no gamma-ray excess is observed, we show the limits HAWC can place on the dark matter cross-section from these sources. In particular, in the case of dark matter annihilation into gauge bosons, HAWC will be able to detect a narrow range of dark matter masses to cross-sections below thermal. HAWC should also be sensitive to non-thermal cross-sections for masses up to nearly 1000 TeV. The constraints placed by HAWC on the dark matter cross-section from known sources should be competitive with current limits in the mass range where HAWC has similar sensitivity. HAWC can additionally explore higher dark matter masses than are currently constrained.Comment: 15 pages, 4 figures, version to be published in PR

    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

    At the beginnings of the funerary Megalithism in Iberia at Campo de Hockey necropolis

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    The excavations undertaken at the Campo de Hockey site in 2008 led to the identification of a major Neolithic necropolis in the former Island of San Fernando (Bay of Cádiz). This work presents the results of the latest studies, which indicate that the site stands as one of the oldest megalithic necropolises in the Iberian Peninsula. The main aim of this work is to present with precision the chronology of this necropolis through a Bayesian statistical model that confirms that the necropolis was in use from c. 4300 to 3800 cal BC. The presence of prestige grave goods in the earliest and most monumental graves suggest that the Megalithism phenomenon emerged in relation to maritime routes linked to the distribution of exotic products. We also aim to examine funerary practices in these early megalithic communities, and especially their way of life and the social reproduction system. As such, in addition to the chronological information and the Bayesian statistics, we provide the results of a comprehensive interdisciplinary study, including anthropological, archaeometric and genetic data.Archaeological background: the Campo de Hockey settlement Methods - Tomb typology - Radiocarbon dates and Bayesian analysis. - Bioarchaeology. - DNA - Grave goods Results - Tomb typology - Radiocarbon dating: Bayesian analysis - Bioarchaeology. - DNA - Grave goods. Discussion and conclusions

    At the beginnings of the funerary Megalithism in Iberia at Campo de Hockey necropolis

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    [EN] The excavations undertaken at the Campo de Hockey site in 2008 led to the identification of a major Neolithic necropolis in the former Island of San Fernando (Bay of Cadiz). This work presents the results of the latest studies, which indicate that the site stands as one of the oldest megalithic necropolises in the Iberian Peninsula. The main aim of this work is to present with precision the chronology of this necropolis through a Bayesian statistical model that confirms that the necropolis was in use from c. 4300 to 3800 cal BC. The presence of prestige grave goods in the earliest and most monumental graves suggest that the Megalithism phenomenon emerged in relation to maritime routes linked to the distribution of exotic products. We also aim to examine funerary practices in these early megalithic communities, and especially their way of life and the social reproduction system. As such, in addition to the chronological information and the Bayesian statistics, we provide the results of a comprehensive interdisciplinary study, including anthropological, archaeometric and genetic data.We wish to express our gratitude to Antonio Saez Espligares (Historical Museum of San Fernando) and Lourdes Lorenzo (Figlina, s.l.) for their support during the archaeological excavation. This research was conducted in the framework of the following research projects: "Analysis of prehistoric societies from the Middle Palaeolithic to the Late Neolithic at both sides of the Strait of Gibraltar: relations and contacts", funded by the State Research Agency (SRA) and the European Regional Development Fund (ERDF). Ref.: HAR2017-87324-P. (2018-2021). "Analisis interdisciplinar para el conocimiento del poblamiento humano de la Bahia de Cadiz durante la Prehistoria Reciente (VI-II milenios a.n.e.)", funded by 2014-2020 ERDF Operational Programme and the Department of Economy, Knowledge, Business and University of the Regional Government of Andalusia. Ref.: FEDER-UCA18-106917 (2020-2023). "Analisis de los isotopos de oxigeno en conchas y de los isotopos estables de oxigeno y carbono en huesos humanos en el poblado neolitico insular de Campo de Hockey (San Fernando, Cadiz)", authorised and funded by CEIMAR. Ref.: CEIJ-015 (2018-2019). Eduardo Molina Piernas acknowledges co-funding from European Social Fund (D1113102E3) and Junta de Andalucia
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