793 research outputs found

    Ferromagnetism in bulk Co-Zn-O

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    The origin of ferromagnetism in diluted magnetic semiconductors is still an open question, yielding a great deal of research across the world. This work focuses on the Co-Zn-O system. Room-temperature ferromagnetism is observed after a partial reaction of Co_3O_4 and ZnO, which can be ascribed neither to carrier mediation nor segregated cobalt metallic clusters. Another mechanism is yielding room-temperature ferromagnetism. This mechanism is associated with a partial reaction of ZnO and Co_3O_4 grains, and always appears when the starting phases (Co_3O_4 and ZnO) are present in the sample, suggesting that interfaces are involved in the origin of the observed ferromagnetism

    β-N-acetylglucosaminidase grafted on mesoporous silica nanoparticles. A bionanoantibiotic system against Staphylococcus aureus bacteria

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    A bionanoantibiotic system based on beta-N-acetylglucosaminidase (Ami) and Lysozyme (Lyz) enzymes grafted on the external surface of amino functionalized mesoporous silica nanoparticles, having a radial arrangement of pores (MSNr-NH2), was prepared and fully characterized. Before the enzyme grafting the nanoparticles were also loaded with the antibiotic drug levofloxacin (Levo) to explore the possible synergic effect with the enzymes. MSNr-NH2-Lyz-Levo and MSNr-NH2-Ami-Levo did not show any activity against S. aureus. On the contrary, in the absence of the antibiotic, both Lyz and Ami immobilized on MSNr were able to destroy S. aureus cells, suggesting an inhibiting action of the antibiotic on the enzymes. Although the loading of immobilized Lyz was higher than that of Ami (76 vs. 20 mg/g, respectively), the highest antibacterial efficacy was found for MSNr-NH2-Ami nanoantibiotic. Moreover, MSNr-NH2-Ami was active against S. aureus even at very low concentration (12.5 mu g/ mL) with a bactericidal activity (79%), higher than that determined for MSNr-NH2 loaded with levofloxacin (54%). These results suggest the possibility of using enzyme grafted MSNr as a bionanoantibiotic drug with high efficiency even at low nanoparticles concentration

    Electronically Tunable Phase Response for Phased array Patches

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    The design and prototyping of radiating elements with tunable phase response, for reconfigurable patch array antennas, is presented. Different options are found in the technical literature to obtain feasible reconfigurable array antennas: placing the active circuitry in the transmission lines or directly over the radiating element, obtaining the desired phase shift for each radiating element of the array. In this reported work, the second option is selected and active radiating elements at 12 GHz are designed and prototyped

    L'Università per la formazione delle educatrici e degli educatori al patrimonio storico-artistico: riflessioni a partire da una prima mappatura nazionale

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    L’ormai imprescindibile necessità educativa e comunicativa delle istituzioni museali invoca una sempre crescente specializza-zione dei professionisti incaricati di queste funzioni. Sebbene i re-quisiti delle educatrici e degli educatori, delle e dei responsabili dei servizi educativi siano ormai saldamente individuati, la nostra legislazione non riconosce tali figure professionali, aprendo di fatto a uno scollamento tra le necessità dei luoghi e degli istituti della cultura e i percorsi di formazione. Questi ultimi, non trovando riscon-tro nel riconoscimento professionale e dovendo rispondere a precise norme ministeriali in merito alla costruzione dei curricula formativi offerti ai vari livelli, dai diplomi di laurea ai corsi di dotto-rato, non possono che basare le proprie aperture didattiche all’educazione al patrimonio sulle sensibilità dei singoli Atenei, se non dei singoli docenti. Per verificare l’effettiva offerta formativa attualmente proposta dagli atenei nazionali è stata svolta una prima mappatura nazionale sui corsi di laurea di I e II livello, Scuole di Specializzazione e Master di I e II livello, in ambito storico-artistico

    Augmented Reality App with AI-based Pervasive Latency Monitoring of RAN and Programmable Metro Packet-Optical Networks

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    Deep data plane programmability is exploited at different future 6G network technological segments to realize end-to-end application delay telemetry. For the first time, data analytics obtained by RAN controllers and metro network collectors are processed by a Multi Agent System running AI algorithms with the aim of detecting latency anomalies and their location in the network, suggesting the most appropriate recovery countermeasure. The demo is shown applied to Augmented Reality application with extreme low latency requirements

    Synthetic populations of protoplanetary disks. Impact of magnetic fields and radiative transfer

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    Protostellar disks are the product of angular momentum conservation during protostellar collapse. Understanding their formation is crucial because they are the birthplace of planets and their formation is also tightly related to star formation. Unfortunately, the initial properties of Class 0 disks and their evolution are still poorly constrained both theoretically and observationally. Aims: We aim to better understand the mechanisms that set the statistics of disk properties as well as to study their formation in massive protostellar clumps. We also want to provide the community with synthetic disk populations to better interpret young disk observations. Methods: We used the ramses code to model star and disk formation in massive protostellar clumps with magnetohydrodynamics, including the effect of ambipolar diffusion and radiative transfer as well as stellar radiative feedback. Those simulations, resolved up to the astronomical unit scale, have allowed us to investigate the formation of disk populations. Results: Magnetic fields play a crucial role in disk formation. A weaker initial field leads to larger and massive disks and weakens the stellar radiative feedback by increasing fragmentation. We find that ambipolar diffusion impacts disk and star formation and leads to very different disk magnetic properties. The stellar radiative feedback also have a strong influence, increasing the temperature and reducing fragmentation. Comparing our disk populations with observations reveals that our models with a mass-to-flux ratio of 10 seems to better reproduce observed disk sizes. This also sheds light on a tension between models and observations for the disk masses. Conclusions: The clump properties and physical modeling significantly impact disk populations. It is critical to for the tension, with respect to disk mass estimates, between observations and models to be solved with synthetic observations. This is particularly important in the context of understanding planet formation

    Follow-up of multi-messenger alerts with the KM3NeT ARCA and ORCA detectors

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    The strength of multi-messenger astronomy comes from its capability to increase the significance of a detection through the combined observation of events coincident in space and time. This is particularly valuable for transient events, since the use of a narrow time window can allow a reduction of background of the search. In KM3NeT, we are actively monitoring and analysing a variety of external triggers in real-time, including alerts like IceCube neutrinos, HAWC gamma-ray transients, LIGO-Virgo- KAGRA gravitational waves, SNEWS neutrino alerts, and others. In this contribution, we present the follow-up of various external alerts using the comple- mentary capabilities of the two KM3NeT detectors, ORCA (covering the few GeV to few TeV energy range) and ARCA (ranging from sub-TeV energies up to tens of PeV). Both detectors were collecting high-quality data with partial configurations during the period of the studied alerts, which goes from December 2021 until June 2023

    Psychosocial and environmental risk factors of obesity and hypertension in children and adolescents—a literature overview

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    Childhood obesity has become a worldwide epidemic in the 21st century. Its treatment is challenging and often ineffective, among others due to complex, often not obvious causes. Awareness of the existence and meaning of psychosocial and environmental risk factors seems to be an essential element in the prevention and treatment of obesity and its complications, especially arterial hypertension. In this review, we will discuss the role of that risk factors linking obesity and increased cardiovascular disorders including the role of nutritional factors (including the role of unhealthy diet, inadequate hydration), unhealthy behaviors (e.g. smoking, alcohol and drugs, sedentary behavior, low physical activity, disrupted circadian rhythms, sleep disorders, screen exposure), unfavorable social factors (such as dysfunctional family, bullying, chronic stress, mood disorders, depression, urbanization, noise, and environmental pollution), and finally differences in cardiovascular risk in girls and boy
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