184 research outputs found

    Upgrading of Biobased Glycerol to Glycerol Carbonate as a Tool to Reduce the CO2 Emissions of the Biodiesel Fuel Life Cycle

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    With regards to oil-based diesel fuel, the adoption of bio-derived diesel fuel was estimated to reduce CO2 emissions by approximately 75%, considering the whole life cycle. In this paper, we present a novel continuous-flow process able to transfer an equimolar amount of CO2 (through urea) to glycerol, producing glycerol carbonate. This represents a convenient tool, able to both improve the efficiency of the biodiesel production through the conversion of waste streams into added-value chemicals and to beneficially contribute to the whole carbon cycle. By means of a Design of Experiments approach, the influence of key operating variables on the product yield was studied and statistically modeled

    New Silver(I) Coordination Polymer with Fe4 Single-Molecule Magnets as Long Spacer

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    In continuation of our work on supramolecular architectures of single-molecule magnets (SMMs) as a promising strategy in developing their magnetic performance, in this paper we report the synthesis and single crystal X-ray structure of the centered triangular tetrairon(III) SMM, [Fe4(PhpPy)2(dpm)6], Fe4 (Hdpm = dipivaloylmethane, H3PhpPy = 2-(hydroxymethyl)- 2-(4-(pyridine-4-yl)phenyl)propane-1,3-diol), and its assembly in the coordination polymer {[Fe4(PhpPy)2(dpm)6Ag](ClO4)}n, Fe4Ag, upon reaction with silver(I) perchlorate. Thanks to the presence of the pyridyl rings on the two tripodal ligands, Fe4 behaves as divergent ditopic linker, and due to the Fe4:AgClO4 1:1 ratio, Fe4Ag probably possesses a linear arrangement in which silver(I) ions are linearly coordinated by two nitrogen atoms, forming 1D chains whose positive charge is balanced by the perchlorate anions. The stabilization of such a polymeric structure can be ascribed to the long distance between the two donor nitrogen atoms (23.4 \uc5) and their donor power. Fe4Ag shows slow relaxation of the magnetization which follows a thermally activated process with Ueff/kB = 11.17(18) K, t0 = 2.24(17) 107 s in zero field, and Ueff/kB = 14.49(5) K, t0 = 3.88(8) 107 s in 1-kOe applied field, in line with what reported for tetrairon(III) SMMs acting as building blocks in polymeric structures

    Vivisecting galaxies with BANG: an automated morpho-kinematical decomposition of the SDSS-DR17 MaNGA survey

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    From a purely photometric perspective galaxies are generally decomposed into a bulge+disc system, with bulges being dispersion-dominated and discs rotationally-supported. However, recent observations have demonstrated that such framework oversimplifies complexity, especially if one considers galaxy kinematic.To address this issue we introduced with the GPU-based code \textsc{bang} a novel approach that employs analytical potential-density pairs as galactic components, allowing for a computationally fast, still reliable fit of the morphological and kinematical properties of galaxies. Here we apply \textsc{bang} to the SDSS-MaNGA survey, estimating key parameters such as mass, radial extensions, dynamics, for both bulges and discs of +10,000 objects. We test our methodology against a smaller subsample of galaxies independently analysed with an orbit-based algorithm, finding agreement in the recovered total stellar mass. We also manage to reproduce well-established scaling relations, demonstrating how a proper dynamical modelling can result in tighter correlations and provide corrections to standard approaches. Finally, we propose a more general way of decomposing galaxies into "hot" and "cold" components, showing a correlation with orbit-based approaches and visually determined morphological type. Unexpected tails in the "hot-to-total" mass-ratio distribution are present for galaxies of all morphologies, possibly due to visual morphology misclassifications.Comment: 13 pages, 10 figure

    Supporting a transition towards sustainable circular economy: sensitivity analysis for the interpretation of LCA for the recovery of electric and electronic waste

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    Purpose: The interpretation is a fundamental phase of life cycle assessment (LCA). It ensures the robustness and the reliability of the overall study. Moving towards more circular economy requires that different waste management options are systematically scrutinized to assess the environmental impacts and benefits associated to them. The present work aims at illustrating how a sensitivity analysis could be applied to the impact assessment step supporting the interpretation of a LCA study applied to a waste management system that includes material recovering. The focus is on toxicity-related and resource-related potential impacts as they are considered among the most critical ones, which may affect the way the final benefit from material recovery is evaluated. Methods: Possible alternatives in terms of impact assessment assumptions and modelling are tested by performing a sensitivity analysis on a case study on electric and electronic waste. For the toxicity-related impact categories, first, a sensitivity analysis is performed using different sets of characterization factors for metals aiming at identifying how they are affecting the final results. Then, an analysis of the relative contribution of long-term emissions in upstream processes is carried out aiming at unveiling critical issues associated to their inclusion or exclusion. For the resource depletion impact category, a sensitivity analysis has been performed, adopting different sets of characterization factors based on existing models for minerals and metals as well as recently proposed sets accounting for critical raw materials. Results and discussion: The indicator of the ecotoxicity impact category obtained by applying the updated characterization factors is about three times higher than the corresponding obtained by the USEtox model. The long-term emission result is responsible for the major part of all the toxicity impact indicators. Moreover, for the ecotoxicity indicator, excluding the long-term emissions changes the total results from being negative into positive. The sensitivity analysis for the resource depletion impact category shows that all the models applied result in a total avoided impact. A quantitative comparison among all the results is not possible as the different models use different units of measure. Conclusions: The application of LCA is crucial for assessing avoided impacts and uncovers potential impacts due to recycling. However, contrasting results may stem from the application of different assumptions and models for characterization. A robust interpretation of the results should be based on systematic assessment of the differences highlighted by the sensitivity, as guidance for delving into further analysis of the drivers of impacts and/or to steer ecoinnovation to reduce those impacts

    Gli uccelli della provincia di Novara (Piemonte, Italia): distribuzione, abbondanza e stato di conservazione

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    In questo lavoro viene riportato un elenco commentato degli uccelli noti per la provincia di Novara (1.340 km2) aggiornato al 31/12/2016 e vengono forniti dati di sintesi relativi alle attività di monitoraggio condotte in anni recenti (2009-2016). I dati sono stati raccolti sia attraverso revisione bibliografica sia attraverso attività di ricerca diretta sul campo. L'avifauna della provincia di Novara annovera o ha annoverato (dal 1860 al 2016) 304 specie delle quali 135 nidificanti certe o probabili in tempi recenti (dopo il 2000), 85 di interesse comunitario (Allegato I della Direttiva "Uccelli"), 116 SPEC - Species of European Conservation Concern secondo BirdLife International e 53 inserite nella European Red List of Birds. L'area è di importanza europea e/o nazionale per la nidificazione di specie di interesse conservazionistico quali Egretta garzetta (650-1.100 nidi), Nycticorax nycticorax (200-300 nidi), Botaurus stellaris (5-7 maschi cantori), Ciconia nigra (1-2 coppie), Ciconia ciconia (4-6 coppie), Himantopus himantopus (300-500 coppie), Vanellus vanellus (500-600 coppie), Columba oenas (20-30 coppie), nonché per la migrazione di Philomachus pugnax (5.000-7.000 ind.) e Tringa glareola (500-1.500 ind.). Negli ultimi anni (2009-2016) si segnalano in particolare: la nidificazione accertata per la prima volta nel Novarese di Ardea alba, Galerida cristata e Lullula arborea; il ritorno di Burhinus oedicnemus e Chlidonias niger in periodo riproduttivo dopo decenni di assenza; la colonizzazione da parte di Dryocopus martius degli ambienti forestali di collina e di pianura.</p

    Detection of Chlamydial {DNA} from Mediterranean Loggerhead Sea Turtles in Southern Italy

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    Chlamydiae are obligate intracellular bacteria that include pathogens of human and veterinary importance. Several reptiles were reported to host chlamydial agents, but pathogenicity in these animals still needs clarification. Given that only one report of chlamydiosis was described in sea turtles, and that chlamydiae might also be detected in hosts without clinical signs, the current study examined asymptomatic Mediterranean loggerhead sea turtles for the presence of chlamydial DNA. Twenty loggerhead sea turtles, rehabilitated at the Marine Turtle Research Centre (Portici, Italy), were examined collecting ocular-conjunctival, oropharyngeal and nasal swabs. Samples were processed through quantitative and conventional PCR analyses to identify Chlamydiales and Chlamydiaceae, with particular attention to C. pecorum, C. pneumoniae, C. psittaci, and C. trachomatis. Although it was not possible to determine the species of chlamydiae involved, the detection of chlamydial DNA from the collected samples suggests that these microorganisms might act as opportunistic pathogens, and underlines the role of sea turtles as potential carriers. This study highlights the presence of chlamydial agents in sea turtles, and encourages further research to fully characterize these microorganisms, in order to improve the management of the health and conservation of these endangered species, and prevent potential zoonotic implications

    Subclassification of the “Grey Zone” of Thyroid Cytology; A Retrospective Descriptive Study with Clinical, Cytological, and Histological Correlation

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    Undetermined thyroid cytology precludes any definitive distinction between malignant and benign lesions. Recently several classifications have been proposed to split this category into two or more cytological subcategories related to different malignancy risk rates. The current study was performed retrospectively to investigate the results obtained separating “undetermined” cytologic reports into two categories: “follicular lesion” (FL) and “atypia of undetermined significance” (AUS). Biochemical, clinical, and echographic features of each category were also retrospectively analyzed. Altogether, 316 undetermined fine-needle aspirated cytologies (FNACs) were reclassified as 74 FL and 242 AUS. Histological control leads to a diagnosis of carcinomas, adenomas, and nonneoplastic lesions, respectively, in 42.2%, 20%, and 37.8% of AUS and in 8.3%, 69.4%, and 22.2% of FL. Among biochemical, clinical, cytological, and echographic outcomes, altered thyroid autoantibodies, multiple versus single nodule, AUS versus FL, and presence of intranodular vascular flow were statistically significant to differentiate adenoma from carcinoma and from nonneoplastic lesions, whereas no significant differences were found between carcinomas and nonneoplastic lesions for these parameters. The results of this retrospective study show that undetermined FNAC category can further be subclassified in AUS and FL, the former showing higher malignancy rate. Further prospective studies are needed to confirm our results
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