Charge doping and large lattice expansion in oxygen-deficient heteroepitaxial WO3

Tungsten trioxide is a versatile material with widespread applications ranging from electrochromic and optoelectronic devices to water splitting and catalysis of chemical reactions. For technological applications, thin films of WO3 are particularly appealing, taking advantage from high surface-to-volume ratio and tunable physical properties. However, the growth of stoichiometric, crystalline thin films is challenging because the deposition conditions are very sensitive to the formation of oxygen vacancies. In this work, we show how background oxygen pressure during pulsed laser deposition can be used to tune the structural and electronic properties of WO3 thin films. By performing X-ray diffraction and low-temperature transport measurements, we find changes in WO3 lattice volume up to 10%, concomitantly with an insulator-to-metal transition as a function of increased level of electron doping. We use advanced ab initio calculations to describe in detail the properties of the oxygen vacancy defect states, and their evolution in terms of excess charge concentration. Our results depict an intriguing scenario where structural, electronic, optical, and transport properties of WO3 single-crystal thin films can all be purposely tuned by a suited control of oxygen vacancies formation during growth

Dinamiche di influenza personale nei Social Network: il caso Twitter

Nei social network online gli utenti svolgono il duplice ruolo di produttori di contenuti e di nodi interni a una rete di contatti personale. Attraverso lo studio del network in cui gli utenti sono inseriti e tramite l’applicazione delle tecniche di social network analysis, è possibile individuare delle dinamiche di influenza personale. Il social network online scelto per l’analisi è Twitter. In primo luogo vengono esposte le ricerche svolte da Lazarsfeld negli anni ’40 nell’ambito dell’influenza personale, quindi, passando in rassegna diversi studi e le loro conclusioni, viene stabilito come le stesse condizioni e gli stessi meccanismi siano in parte validi per analizzare le dinamiche di influenza sul social network

Identifying technologies in circular economy paradigm through text mining on scientific literature

Technological innovation serves as the catalyst for the shift towards circular practices. Technologies not only address technical challenges, facilitating the transition to a more circular economy, but they also enhance business efficiency and profitability. Furthermore, they promote inclusivity and create job opportunities, ultimately yielding positive societal impacts. The research in this area tends to focus on digital technologies, neglecting other technological areas. Moreover, it heavily relies on literature reviews and expert opinions, potentially introducing biases. In this article we investigate the technological landscape of the circular economy through Natural Language Processing (NLP), examining key technologies used in this sector and the primary challenges in managing these technologies. The methodology is applied to more than 45,000 scientific publications and aims to extract technologies in the text of scientific articles with NLP. The findings of our analysis reveal a strong emphasis on emerging digital, life cycle assessment and biomaterials technologies. Furthermore, we identified seven distinct technological domains within the CE field. Finally, we provide advantages and problems arising in the adoption and implementation of these technologies in an industrial context

Vulnerability Assessment of Industrial Sites to Interface Fires and Wildfires

In the framework of climate change, the hazard caused by wildfires approaching the anthropic settlements is raising an increasing concern. Fatalities and relevant damage to properties were recently caused by wildfires affecting the Wildland-Urban and Wildland-Industrial Interfaces. Industrial sites storing large quantities of hazardous materials are vulnerable to interface fires, which have the potential to trigger specific cascading events such as Natech scenarios followed by domino effects. The present study aims at providing a methodology for the quantitative assessment of the vulnerability of industrial sites exposed to wildfires. The approach provides a novel framework for the identification and quantification of all the chains of failures that may occur due to wildfires or interface fires approaching industrial sites. The methodology accounts for the thermal radiation from fires in both primary Natech scenarios and cascading scenarios triggered by domino effects. The dynamic features of interface fires and the synergistic effects of multiple fires are also taken into account. The results of a case study demonstrated the importance of considering the dynamic behavior of wildfire, which strongly affects the vulnerability of industrial structures. The results also evidence the importance of emergency management and first response on the overall vulnerability figures

(Dipyrido[3,2-a:2',3'-c]phenazine)(glycinato)copper(II) perchlorate: A novel DNA-intercalator with anti-proliferative activity against thyroid cancer cell lines

A novel copper(II) heteroleptic complex of dipyrido[3,2-a:2′,3′-c]phenazine (dppz) and glycinato (gly) as chelating ancillary ligand, [Cu(dppz)(gly)]ClO4 (1), was synthesized and characterized. X-ray crystallography revealed that the coordination geometry of the cationic [Cu(dppz)(gly)]+ unit is hexacoordinated and shows a distorted octahedral coordination geometry in the solid state, with the N,N and N,O chelating atoms of dppz and glycinato, respectively, in the square plane and in which the planar units are connected in a monodimensional polymeric array by the apical copper coordination of the second carboxylic oxygen atom. Biological assays showed that 1 exhibits a remarkable anti-proliferative activity against the two human anaplastic thyroid cancer cell lines 8505c (BrafV600E/V600E) and SW1736 (BrafWT/V600E), in a dose- and time-dependent manner. In details, the IC50 after 48 h of drug exposure was 2.86±0.54 μM for SW1736 and 1.05±0.48 μM for 8505c. On the other hand, the IC50 shown by cis-diamminedichloroplatinum(II) (cisplatin) against the same cell lines was 2.50±0.40 μM and 6.03±0.78 μM, respectively. Optical microscopy observations, after 48 h of treatment, showed morphological cell changes typical of apoptosis, confirmed by DNA ladder assays. DNA interaction studies, performed by UV absorption spectrophotometry, circular dichroism and viscosimetry, clearly showed that [Cu(dppz)(gly)]ClO4 is a DNA-intercalator, with a DNA-binding constant, Kb, of 2.1×106 M−1, suggesting that the mechanism of the cytotoxic activity can be related to its DNA-binding

Sensitivity of Pollutant Concentrations to the Turbulence Schemes of a Dispersion Modelling Chain over Complex Orography

Atmospheric circulation over mountainous regions is more complex than over flat terrain due to the interaction of flows on various scales: synoptic-scale flows, thermally-driven mesoscale winds and turbulent fluxes. In order to faithfully reconstruct the circulation affecting the dispersion and deposition of pollutants in mountainous areas, meteorological models should have a sub-kilometer grid spacing, where turbulent motions are partially resolved and the parametrizations of the sub-grid scale fluxes need to be evaluated. In this study, a modelling chain based on the Weather Research and Forecasting (WRF) model and the chemical transport model Flexible Air Quality Regional Model (FARM) is applied to estimate the pollutant concentrations at a 0.5 km horizontal resolution over the Aosta Valley, a mountainous region of the northwestern Alps. Two pollution episodes that occurred in this region are reconstructed: one summer episode dominated by thermally-driven winds, and one winter episode dominated by synoptic-scale flows. Three WRF configurations with specific planetary boundary layer and surface layer schemes are tested, and the numerical results are compared with the surface measurements of meteorological variables at twenty-four stations. For each WRF configuration, two different FARM runs are performed, with turbulence-related quantities provided by the SURface-atmosphere interFace PROcessor or directly by WRF. The chemical concentrations resulting from the different FARM runs are compared with the surface measurements of particulate matter of less than 10 µm in diameter and nitrogen dioxide taken at five air quality stations. Furthermore, these results are compared with the outputs of the modelling chain employed routinely by the Aosta Valley Environmental Protection Agency, based on FARM driven by COSMO-I2 (COnsortium for Small-scale MOdelling) at 2.8 km horizontal grid spacing. The pollution events are underestimated by the modelling chain, but the bias between simulated and measured surface concentrations is reduced using the configuration based on WRF turbulence parametrizations, which imply a reduced dispersion

String Stability of a Vehicular Platoon with the use of Macroscopic Information

We investigate the possibility to use macroscopic information to improve control performance of a vehicular platoon composed of autonomous vehicles. A general mesoscopic traffic modeling is described, and a closed loop String Stability analysis is performed using Input-to-State Stability (ISS) results. Examples of mesoscopic control laws are provided and shown to ensure String Stability properties. Simulations are implementedin order to validate the control laws and to show the efficacy of the proposed approach.Comment: arXiv admin note: substantial text overlap with arXiv:2003.1252

Datacenter in a box: test your SDN cloud-datacenter controller at home

In the last years, the widespread of Cloud computing as the main paradigm to deliver a large plethora of virtualized services significantly increased the complexity of Datacenters management and raised new performance issues for the intra-Datacenter network. Providing heterogeneous services and satisfying users’ experience is really challenging for Cloud service providers, since system (IT resources) and network administration functions are definitely separated. As the Software Defined Networking (SDN) approach seems to be a promising way to address innovation in Datacenters, the paper presents a new framework that allows to develop and test new OpenFlow–based controllers for Cloud Datacenters. More specifically, our framework enhances both Mininet (a well–known SDN emulator) and POX (a network controller written in python), with all the extensions necessary to experiment novel control and management strategies of IT and network resources.FEDER Funds through the Programa Operacional Fatores de Competitividade - COMPETE and by National Funds through the FCT - Fundação para a Ciência e a Tecnologia (Portuguese Foundation for Science and Technology) within project FCOMP-01-0124-FEDER-022674Italian Ministry of University and Research funded project Green-Net (contract n. RBFR100QHJ

Promoting STEM via UMI: an Ecological Framing of CoPs in Networking and Networked Robotics

Ubiquitous Computing, Mobile Computing and Internet of Things (UMI) technologies, are widely diffused in the everyday life. In addition to their primary usage (e.g., supporting the implementation of the future 5G network),these technologies can be used in the context of Science Education.According to this perspective, the innovative psycho-pedagogical approach here presented has been ad-hoc developed for the Horizon 2020 Project “Exploiting Ubiquitous Computing, Mobile Computing and the Internet of Things to promote Science Education” (Umi-Sci-Ed). The aim of the project is to enhance knowledge and skills of Science, Technology, Engineering and Mathematics (STEM) and to promote positive attitudes towards these disciplines. In order to reach this goal, the UMI technologies, framed in the Community of Practices (CoPs) paradigm, will be introduced in the learning process of secondary schools’ students (i.e., 9thand 10thgrade). Specifically, the students will attend to innovative learning activities, such as hands-on activities, concerning with Networking and networked Robotics. In the present contribution, the theoretical framework that constitutes the rationale for the Umi-Sci-Ed projectwill be described. In particular, the “bottom-up” socio-constructionist perspective will be presented, aswell as the main technological tools (e.g., UDOO) that would be used to implement an integrated STEM learning environment. The expected results of the project will be discussed