2,880 research outputs found

    Nanosecond dynamics in few-layer and heterojunction transition metal dichalcogenides from liquid phase exfoliation

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    The lifetimes of photogenerated charge carriers must be long enough to guarantee high efficiency of light harvesting devices. Two-dimensional transition metal dichalcogenides (TMDs) are promising materials due to their intense lightmatter interaction. Liquid phase exfoliation is a low-cost, versatile, scalable method able to produce polydisperse nanosheets in the form of inks. Here, we use nanosecond transient absorption spectroscopy to investigate the charge carrier dynamics in MoS2, WS2, and heterojunctions (HJs) of the two. We observe that the HJ stacking order does not affect the dynamics. We find that in thicker and larger flakes of the single material the carrier lifetime is significantly longer than even in HJs, due to different electronic contributions from nanosheet basal plane and edges. We conclude that there is no need for additional complexity in stacking two TMDs, and transport properties are enhanced in thicker and larger flakes. Our findings can be exploited for device fabrication

    Optimal design of drip irrigation submains: presure-compensating emitters

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    For a drip irrigation system to be successful, it must he well designed, properly installed, managed and maintained. In plots with steep slopes and irregular topography that have little land leveling capacity and/or that require very efficient agricultural machinery, drip irrigation designs generally use pressure-compensating emitters. This work develops a methodology and implements it in a computer tool that makes it possible to optimally determine in drip-irrigated plots with pressure-compensating emitters: a) telescopic sizing of the submain manifold pipe, b) supply valve pressure and c) subunit''s intake valve location, when considering all hydraulic-economic aspects in the design phase. Techniques of optimal sizing of pipe networks and simulation of hydraulic networks under pressure are linked to economic analyzes of total annualized costs. Finally, the practical usefulness of the proposed methodology is shown with three examples of complex real cases where pipe design costs are reduced by 16-34% and energy costs by 37-51%

    New Perspectives on the Sanctuary of Aesculapius in Nora (Sardinia): From Photogrammetry to Visualizing and Querying Tools

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    The ritual space of the Sanctuary of Aesculapius in Nora (Sardinia) is the main focus of a recent archaeological campaign led by the Cultural Heritage Department of the University of Padova. A partnership with 3DOM research group (Fondazione Bruno Kessler, Trento) has offered new opportunities for a digital investigation of the site. The aim of the project is to map and visualize the sanctuary with methodologies enabling different users to engage with the site in new ways. They offer different web tools for exploring, understanding and interacting with the site, by focusing on 3D modelling, semantic enrichment and the contextualization of digital records. The entire site of Nora has been surveyed by a drone, which produced a digital model of the peninsula. A number of outputs have been used for different scales of visualization and a range of purposes: an open source multi-resolution web renderer is used to navigate the point cloud, labelled using a system of bounding boxes. At the same time it provides access to a 2.5D model of each building. Plugins in QGIS are used to produce extrusions of any mapped feature, gaining height values from the point cloud, and attributes from the shapefile. Photogrammetric models of single ritual artifacts can be located in their own context and be displayed using 3D web renderers

    Knowledge and valorization of historical sites through 3D documentation and modeling

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    The paper presents the first results of an interdisciplinary project related to the 3D documentation, dissemination, valorization and digital access of archeological sites. Beside the mere 3D documentation aim, the project has two goals: (i) to easily explore and share via web references and results of the interdisciplinary work, including the interpretative process and the final reconstruction of the remains; (ii) to promote and valorize archaeological areas using reality-based 3D data and Virtual Reality devices. This method has been verified on the ruins of the archeological site of Pausilypon, a maritime villa of Roman period (Naples, Italy). Using Unity3D, the virtual tour of the heritage site was integrated and enriched with the surveyed 3D data, text documents, CAAD reconstruction hypotheses, drawings, photos, etc. In this way, starting from the actual appearance of the ruins (panoramic images), passing through the 3D digital surveying models and several other historical information, the user is able to access virtual contents and reconstructed scenarios, all in a single virtual, interactive and immersive environment. These contents and scenarios allow to derive documentation and geometrical information, understand the site, perform analyses, see interpretative processes, communicate historical information and valorize the heritage location

    Feeding and oviposition preferences of Monochamus galloprovincialis on its main hosts Pinus sylvestris and Pinus pinaster

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    Θεωρώντας τον ρόλο του Monochamus galloprovincialis κλειδί στην εξάπλωση του νηματώδη του πεύκου στην Ευρώπη, η διαλεύκανση του εύρους των ξενιστών και των προτιμήσεων του Μ. galloprovincialis σε αυτούς είναι πρωτεύουσας σημασίας για την προστασία του δάσους. Συγκριτικές μελέτες σε συνθήκες εργαστηρίου διεξήχθησαν με σκοπό την διευκρίνηση των διατροφικών και ωοθετικών προτιμήσεων των ενηλίκων αυτού του εντόμου καθώς και της ανάπτυξης των προνυμφών του στα P. sylvestris και P. pinaster. Η διατροφή και η ωοτοκία βρέθηκαν στατιστικά πιο σημαντικές στο P. sylvestris αλλά καμία διαφορά δεν βρέθηκε στην επιβίωση των προνυμφών στα δύο είδη πεύκου. Οι προνύμφες έφτασαν στην 4η ηλικία νωρίτερα στο P. sylvestris από ότι στο P. pinaster. Τα αποτελέσματα της παρούσης μελέτης ισχυροποιούν τις υποψίες για μια γρήγορη μελλοντική εξάπλωση του νηματώδη σε ολόκληρη την Ευρώπη.Considering the key role of Monochamus galloprovincialis (Olivier) (Coleoptera: Cerambycidae) in the dispersion of the pine wood nematode, Bursaphelenchus xylophilus (Steiner & Bührer) Nickle (Nematoda: Aphelenchoidea), in Europe, defining the host spectrum and preference of M. galloprovincialis is of primary importance for forest management. Therefore, comparative studies under laboratory conditions were performed in order to define the feeding and oviposition preferences of M. galloprovincialis adults as well as the larval development on Pinus sylvestris and Pinus pinaster. Both nutrition and oviposition were significantly higher on P. sylvestris. However, no difference was found when comparing larval survival on the two Pinus species even though larvae attended the fourth instar earlier when reared on P. sylvestris than on P. pinaster. The results of this study reinforce the suspicions of a future rapid propagation of the nematode, by M. galloprovincialis, into the Pine forests all over Europe

    Feeding and oviposition preferences of Monochamus galloprovincialis on its main hosts Pinus sylvestris and Pinus pinaster

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    Θεωρώντας τον ρόλο του Monochamus galloprovincialis κλειδί στην εξάπλωση του νηματώδη του πεύκου στην Ευρώπη, η διαλεύκανση του εύρους των ξενιστών και των προτιμήσεων του Μ. galloprovincialis σε αυτούς είναι πρωτεύουσας σημασίας για την προστασία του δάσους. Συγκριτικές μελέτες σε συνθήκες εργαστηρίου διεξήχθησαν με σκοπό την διευκρίνηση των διατροφικών και ωοθετικών προτιμήσεων των ενηλίκων αυτού του εντόμου καθώς και της ανάπτυξης των προνυμφών του στα P. sylvestris και P. pinaster. Η διατροφή και η ωοτοκία βρέθηκαν στατιστικά πιο σημαντικές στο P. sylvestris αλλά καμία διαφορά δεν βρέθηκε στην επιβίωση των προνυμφών στα δύο είδη πεύκου. Οι προνύμφες έφτασαν στην 4η ηλικία νωρίτερα στο P. sylvestris από ότι στο P. pinaster. Τα αποτελέσματα της παρούσης μελέτης ισχυροποιούν τις υποψίες για μια γρήγορη μελλοντική εξάπλωση του νηματώδη σε ολόκληρη την Ευρώπη.Considering the key role of Monochamus galloprovincialis (Olivier) (Coleoptera: Cerambycidae) in the dispersion of the pine wood nematode, Bursaphelenchus xylophilus (Steiner & Bührer) Nickle (Nematoda: Aphelenchoidea), in Europe, defining the host spectrum and preference of M. galloprovincialis is of primary importance for forest management. Therefore, comparative studies under laboratory conditions were performed in order to define the feeding and oviposition preferences of M. galloprovincialis adults as well as the larval development on Pinus sylvestris and Pinus pinaster. Both nutrition and oviposition were significantly higher on P. sylvestris. However, no difference was found when comparing larval survival on the two Pinus species even though larvae attended the fourth instar earlier when reared on P. sylvestris than on P. pinaster. The results of this study reinforce the suspicions of a future rapid propagation of the nematode, by M. galloprovincialis, into the Pine forests all over Europe

    Towards Socially and Emotionally Believable ICT Interfaces

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    In order to realize an artificial intelligence focused on human needs, it is necessary to identify the interactional characteristics that describe human mood, social behavior, beliefs, and experiences. The cross-modal analysis of communicative macro-signals represents the first step in this direction. The second step requires the definition of adequate mathematical representations of these signals to validate them perceptively (on the human side) and computationally

    Diagnostic value of presepsin for bacterial infection in cirrhosis: a pilot study

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    Introduction: Presepsin (or sCD14) has been identified as a protein whose levels increase specifically in the blood of patients with bacterial infections. In this study, we evaluated the clinical performance of sCD14 and its usefulness in the early diagnosis of bacterial infection in decompensated cirrhotic patients. Materials: Seventy patients were enrolled in this study. The mean age of patients was 49.5 years, and 21 were women and 49 men. The heparinized whole blood for the PATHFAST test was used in the evaluation of bacterial infection (T0). The test was repeated after 48 hours (T1); at 96 hours (T2); at 144 hours (T3); then at 15 days (T4) to monitor the clinical responses to therapeutic interventions. Results: Forty-nine patients tested positive for sCD14. The mean sCD14 level was 1854 ± 1744 pg/mL. Microbiological findings confirmed the presence of bacterial infections within 84 ± 4.8 h from enrollment in all 49 positive patients. Thirty-eight patients were considered responders to empirical antibiotic therapy with a decrease of presepsin at the different time points, while an increased level of sCD14 was highlighted in 11 patients. When the test was performed, 45% of the patients showed no signs or symptoms of bacterial infection. At 30 days of follow-up 43 patients survived, and 6 patients died from septic shock. Conclusions: The PATHFAST test highlighted the presence of infection in a very short time (15 minutes), and the presepsin could be considered an early biomarker in patients with cirrhosis. A greater number of patients are necessary to confirm these data
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