24 research outputs found

    Study of Oxidation and Combustion Characteristics of Iron Nanoparticles under Idealized and Enginelike Conditions

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    This document is the Accepted Manuscript version of a Published Work that appeared in final form in Energy Fuels, copyright © American Chemical Society after peer review and technical editing by the publisher.[EN] The present work includes findings from proof-of-principle feasibility studies on iron nanopowder combustion under idealized, enginelike, and real engine conditions. The study was conducted under the scope of recent interest in metallic nanoparticles as alternative fuels for internal combustion engines. More specifically, Fe nanoparticles with different morphologies and average primary particle sizes ranging from 25 to 85 nm were studied with respect to their oxidation characteristics via thermogravimetric analysis as well as in customized shock tube, constant-volume vessel, and compression-ignition (CI) engine configurations. Combusted powder samples were in all cases examined via in situ and ex situ techniques for the identification of combustion products and their morphologies. The findings facilitated the determination of the main phenomena involved during oxidation. The results verified that combustion of Fe nanoparticles in a slightly modified CI engine is feasible, albeit with various technological challenges related to ignition and scavenging that inhibit combustion quality.The authors thank the European Commission for partial funding of this work through the Project “COMETNANO” (FP7-NMP4-SL-2009-229063).Mandilas, C.; Karagiannakis, G.; Konstandopoulos, AG.; Beatrice, C.; Lazzaro, M.; Di Blasio, G.; Molina, S.... (2016). Study of Oxidation and Combustion Characteristics of Iron Nanoparticles under Idealized and Enginelike Conditions. Energy and Fuels. 30(5):4318-4330. https://doi.org/10.1021/acs.energyfuels.6b00121S4318433030

    Contributi alla flora vascolare di Toscana. VII (357-439)

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    New localities and/or confirmations concerning 83 specific and subspecific plant taxa of Tuscan vascular flora, belonging to 71 genera and 33 families are presented: Carpobrotus (Aizoaceae), Alternanthera (Amaranthaceae), Leucojum (Amaryllidaceae), Anacyclus, Andryala, Carduus, Centaurea, Cichorium, Erigeron, Helichrysum, Helminthotheca, Hieracium, Limbarda, Pilosella, Scolymus, Sonchus, Tagetes, Urospermum, Xanthium (Asteraceae), Mahonia (Berberidaceae), Myosotis (Boraginaceae), Biscutella, Ionopsidium, Raphanus, Rapistrum (Brassicaceae), Buxus (Buxaceae), Vaccaria (Caryophyllaceae), Cistus (Cistaceae), Calystegia, Cuscuta (Convolvulaceae), Cymodocea (Cymodoceaceae), Cyperus (Cyperaceae), Amorpha, Emerus, Lathyrus, Lotus, Ononis, Trifolium, Vicia (Fabaceae), Quercus (Fagaceae), Geranium (Geraniaceae), Myriophyllum (Haloragaceae), Malva (Malvaceae), Epipogium, Himantoglossum (Orchidaceae), Orobanche (Orobanchaceae), Osyris (Santalaceae), Oxalis (Oxalidaceae), Pinus (Pinaceae), Anisantha, Avellinia, Avena, Corynephorus, Crypsis, Cutandia, Elytrigia, Lolium, Panicum, Polypogon, Sporobolus (Poaceae), Rumex (Polygonaceae), Lysimachia (Primulaceae), Eranthis, Ranunculus (Ranunculaceae), Rubus (Rosaceae), Crucianella, Galium (Rubiaceae), Verbascum (Scrophulariaceae), Solanum (Solanaceae), Tamarix (Tamaricaceae), Viola (Violaceae). In the end, the conservation status of the units and eventual protection of the cited biotopes are discussed

    Suono e Spettacolo. Athanasius Kircher, un percorso nelle Immagini sonore.

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    The Society of Jesus made great propaganda efforts throughout the seventeenth century and chose the images and the play as a privileged means to communicate and persuade. Athanasius Kircher, a key figure of the seventeenth century, he decided to dominate the wild nature of sound through Phonurgia Nova, which includes a gallery of powerful symbolic images for Baroque aesthetics. The essay, through the grant of the images from the Library of the Department of Mathematics "Guido Castelnuovo" Sapienza University of Rome, aims to understand, through the pictures offered by Kircher, the sound phenomenon and the spectacle that this produces. In Phonurgia Nova a process of dramatization sound effects takes place, often through machines and "visions" applied to the theatrical reality, as experimental and astonishing environment beloved in baroque. Kircher illustrates the sound through explanatory figures, so to dominate the sound through the eyes. Sound is seen, admired and represented: its spectacle not only takes place through the implementation of sound machines or the "wonders" applied to the theater, but even through images, creating create a sense of wonder in in the erudite person of the seventeenth century

    The incidence of alien species on the taxonomic, phylogenetic, and functional diversity of lentic and lotic communities dominated by

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    This study aims to investigate, for the first time, the multiple diversity harbored in plant communities dominated by P. australis, discriminating between lentic and lotic habitats. We focused on the incidence of alien species on taxonomical, phylogenetic and functional diversity. Although it was hypothesized that ecological differences between habitats (lentic vs. lotic) could lead to plant adaptive trade-offs, results showed that the P. australis dominance affected overall plant diversity in the same way in both target habitats. Similarly, the two compared habitats hosted a similar alien species richness and relative abundance. Different results were observed based on whether the alien species richness or their relative abundance were considered regarding the incidence of alien species. Increasing alien species richness in lentic habitats resulted in increased taxonomic, phylogenetic and functional diversity. Instead, in lotic habitats, it promoted a decrease in taxonomic and functional diversity. In contrast, the increase in the relative abundance of alien species resulted in increased taxonomic, phylogenetic and functional diversity in both habitats. Choosing relative abundance vs richness of aliens in lotic stands can have a different impact in evaluating the effect of aliens on various components of diversity

    The role of transportation in the spread of Brachyspira hyodysenteriae in fattening farms

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    Abstract Background Direct and indirect contact among animals and holdings are important in the spread of Brachyspira hyodysenteriae. The objective of this study was to investigate the role of slaughterhouse vehicles in spreading B. hyodysenteriae between unconnected farms. Results Multilocus sequence typing (MLST) and Multiple Locus Variable number tandem repeat Analysis (MLVA) were used to characterize B. hyodysenteriae strains isolated from trucks. Before cleaning, 976 batches of finishing pigs transported by 174 trucks from 540 herds were sampled. After cleaning, 763 of the 976 batches were also sampled. Sixty-one of 976 and 4 of 763 environmental swabs collected from trucks before and after cleaning and disinfection operations, respectively, were positive for B. hyodysenteriae. The 65 isolates in this study originated from 48 farms. Trucks were classified into five categories based on the number of visited farms as follows: category 1: 1–5 farms, category 2: 6–10 farms, category 3: 11–15 farms, category 4: 16–20 farms, category 5: >21 farms. Although the largest number of vehicles examined belonged to category 1, the highest percentage of vehicles positive for B. hyodysenteriae was observed in categories 3, 4 and 5. Specifically, 90.9% of trucks belonging to category 5 were positive for B. hyodysenteriae, followed by categories 4 and 3 with 85.7% and 83.3%, respectively. The results of MLST and MLVA suggest that trucks transporting pigs from a high number of farms also play a critical role in spreading different B. hyodysenteriae genetic profiles. STVT 83–3, which seems to be the current dominant type in Italy, was identified in 56.25% of genotyped isolates. The genetic diversity of isolated strains from trucks was high, particularly, in truck categories 3, 4 and 5. This result confirmed that MLST and MLVA can support the study of epidemiological links between different B. hyodysenteriae farm strains. Conclusions This study highlights the potential role of shipments in B. hyodysenteriae spread. Moreover, it emphasizes the importance of strict vehicle hygiene practices for biosecurity programmes

    Comparative evaluation of immune responses of swine in PRRS-stable and unstable herds

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    Porcine Reproductive and Respiratory Syndrome (PRRS) is an elusive model of host/virus relationship in which disease is determined by virus pathogenicity, pig breed susceptibility and phenotype, microbial infectious pressure and environmental conditions. Successful disease control in PRRS-endemic Countries corresponds to "stability", i.e. a condition with no clinical signs of PRRS in the breeding-herd population and no viremia in weaning-age pigs. The aim of this work was to compare the profile and time-course of humoral and cell-mediated immunity in stable and unstable herds, respectively. In particular, we investigated PRRS virus (PRRSV) in serum and group oral fluid samples by Real-time RT-PCR, PRRSV-specific IgA and IgG in oral fluids, serum IgG antibody and the cell-mediated response (PRRSV-specific release of interferon-gamma) in whole blood samples. These parameters were measured in order to identify possible discrepancies in the development and kinetics of the immune response against PRRSV. PRRS-free gilts got regularly infected after entering PRRS-stable and unstable farms. In an open cycle, unstable pig farm PRRSV infection could be demonstrated in all groups of pigs, including suckling piglets. Four main results should be highlighted: A) the precocity of the Ab response in group oral fluids was generally similar to that recorded in sera; B) circulation of PRRSV was consistently detected in all age groups in the unstable herds, as opposed to the stable ones; C) an early, balanced, IgA and IgG response in oral fluids was only observed in the stable herds; D) an early IFN-gamma response after PRRSV infection was often observed in stable herds, as opposed to the unstable ones. These were characterized by IFN-gamma responses in piglets, likely due to transfer of maternal immunity. Most important, the mucosal IgA response was associated with cessation of virus excretion in oral fluid samples of PRRS-unstable herds. The above findings indicate that a peculiar profile of immune response to PRRSV can be found in PRRS-stable herds. Therefore, the outlined immune parameters can represent a useful readout system to evaluate successful adaptation to PRRSV based on acclimatization of breeding animals and management of pig flow
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