Nanoscale electron-beam-driven metamaterial light sources

Free-standing and fiber-coupled photonic metamaterials act as nanoscale, free-electron-driven, tuneable light sources: emission occurs at wavelengths determined by structural geometry in response to electron-beam excitation of metamaterial resonant plasmonic modes

Sustainability Determinants of Cultural and Creative Industries in Peripheral Areas.

Cultural and Creative Industries (CCIs) are increasingly recognized as part of the global economy and of growing importance for sustainable local development. However, the exploitation of their full potential depends on several issues concerning their entrepreneurial dimension and the context where they operate. The paper deals with these issues having the scope to investigate the main determinants of CCIs’ sustainability in peripheral areas, to understand what kind of policy could better support the survival of CCIs and development in these areas, according to an end-user perspective. The research is part of an Interreg Greece-Italy project carried out from mid-2018 until the end of 2020 with specific reference to CCIs in Apulia (IT) andWestern Greece (EL). A two-step mixed methodology has been used to figure out regional specializations and the specific aspects of the entrepreneurial structure and business sustainability in the cultural and creative sector (CCs). In the end, the paper shows and discusses the main determinants considered crucial for CCI sustainability, suggesting guidelines for local authorities supporting their economic development

Spin and lattice excitations of a BiFeO3 thin film and ceramics

We present a comprehensive study of polar and magnetic excitations in BiFeO3 ceramics and a thin film epitaxially grown on an orthorhombic (110) TbScO3 substrate. Infrared reflectivity spectroscopy was performed at temperatures from 5 to 900 K for the ceramics and below room temperature for the thin film. All 13 polar phonons allowed by the factor-group analysis were observed in theceramic samples. The thin-film spectra revealed 12 phonon modes only and an additional weak excitation, probably of spin origin. On heating towards the ferroelectric phase transition near 1100 K, some phonons soften, leading to an increase in the static permittivity. In the ceramics, terahertz transmission spectra show five low-energy magnetic excitations including two which were not previously known to be infrared active; at 5 K, their frequencies are 53 and 56 cm-1. Heating induces softening of all magnetic modes. At a temperature of 5 K, applying an external magnetic field of up to 7 T irreversibly alters the intensities of some of these modes. The frequencies of the observed spin excitations provide support for the recently developed complex model of magnetic interactions in BiFeO3 (R.S. Fishman, Phys. Rev. B 87, 224419 (2013)). The simultaneous infrared and Raman activity of the spin excitations is consistent with their assignment to electromagnons

Electron-beam-driven nanoscale metamaterials light sources

Nanoscale light (ultimately laser) and surface plasmon (ultimately 'spaser') sources for numerous potential nanophotonic applications have generated and continue to generate considerable research interest, with a variety of optically- and electrically-pumped sources recently demonstrated. We show experimentally that beams of free electrons can be used to induce light emission from nanoscale planar photonic metamaterials, at wavelengths determined by both the metamaterial design parameters and the electron energy

Nowcasting of convective cells over Italian Peninsula

International audienceThe aim of the study is the individuation of convective cells over the Italian peninsula with the conjunction use of geostationary satellite data (METEOSAT, MSG satellite) in the IR and WV channels and lightning data. We will use GCD (Global Convective Diagnostic) algorithm developed at Aviation Weather Centre (AWC) of NOAA (National Oceanic and Atmospheric Administration). This algorithm is based on the idea that a deep convective cloud will not have any significant moisture above it. This technique works quite well at identifying active deep convection and can be applied to all the world's geostationary satellites. However it does not always agree with lightning sensors. Low topped convection with lightning will be missed. We will extend the capabilities of GCD using lightning data. The new product will be validate over different cases in the central Italy using the C-band polarimetric radar of ISAC-CNR (Institute of Atmospheric Sciences and Climate-of the Italian National Research Council) Rome

Synergic use of SAR imagery and high resolution atmospheric model to estimate marine wind fields : an application in presence of an atmospheric gravity wave episode.

A study aimed at retrieving sea surface wind fields of semi-enclosed basins from combined use of SAR imagery and a high resolution mesoscale numerical atmospheric model, is presented. Two consecutive ERS-2 SAR frames and a set of NOAA/AVHRR and MODIS images acquired over the North Tyrrhenian Sea on March 30, 2000 were used for the analysis. SAR wind speeds and directions at 10 m above the sea surface were retrieved using the semi-empirical backscatter models CMOD4 and CMOD-IFREMER. Surface wind vectors predicted by the meteorological ETA model were exploited as guess input to SAR wind inversion procedure. ETA is a three-dimensional, primitive equation, grid-point model currently operational at the National Centers for Environmental Prediction of the U.S. National Weather Service. The model was adapted to run with a resolution up to about 4.0 Km. It was found that the inversion methodology was not able to resolve wind speed modulations due to the action of an atmospheric gravity wave, called “lee wave”, which occurred in the analyzed area. A simple atmospheric wave propagation model was thus used to account for the SAR observed surface wind speed modulation. Synergy with ETA model outputs was further exploited in simulations where atmospheric parameters up-wind the atmospheric wave were provided as input to the lee wave propagation model

Measles among healthcare workers in Italy. Is it time to act?

Vaccination of healthcare workers (HCWs) against measles is strongly recommended in Europe. In this study, we examined the impact of measles on Italian HCWs by systematically and quantitatively analyzing measles cases involving HCWs over time and by identifying the epidemiological characteristics of the respective measles outbreaks. We retrieved data on measles cases from the Italian national integrated measles and rubella surveillance system from January 2013 to May 2019. Additionally, we performed a systematic review of the literature and an analysis of the measles and rubella aggregate outbreaks reporting forms from 2014 to 2018. Our review suggests that preventing measles infection among HCWs in disease outbreaks may be crucial for the elimination of measles in Italy. National policies aiming to increase HCW immunization rates are fundamental to the protection of HCWs and patients, will limit the economic impact of outbreaks on the institutions affected and will help achieve the elimination goal

Evaluation of immunization practices in Naples, Italy.

This paper reports the results of a survey on vaccination coverage among children born in January 1995 and residing at the beginning of the study (March 1998) in the city of Naples, Italy. The percentages vaccinated, at various times from birth, with oral polio vaccine (OPV), have been compared with those found in a similar survey conducted at the end of 1985 regarding the cohort of children born in June 1983. By the fourth month of life 67% of the 1995 cohort were vaccinated with the first doses of OPV, an increase of about 26% on that found in the 1983 cohort. Similar results were found with the second doses. Among the 1995 cohort 49% were vaccinated with the third dose of OPV within the thirteenth month of life; the corresponding value for the 1983 cohort was 33%. Within the twenty-fourth month of life, in the 1995 cohort, 86% completed the primary cycle of vaccination with OPV; the corresponding figure for the 1983 cohort was 65%. At the end of the third year of life 80% of the 1995 cohort received the fourth dose of OPV. A significant association has been found between socioeconomic status and coverage level

Membrane-Based, Liquid–Liquid Separator with Integrated Pressure Control

We describe the development and application of an improved, membrane-based, liquid–liquid separator. Membrane-based separation relies on the exploitation of surface forces and the use of a membrane wetted by one of the phases; however, successful separation requires accurate control of pressures, making the operation and implementation cumbersome. Here we present an improved separator design that integrates a pressure control element to ensure that adequate operating conditions are always maintained. Additionally, the integrated pressure control decouples the separator from downstream unit operations. A detailed examination of the controlling physical equations shows how to design the device to allow operation across a wide range of conditions. Easy to implement, multistage separations such as solvent swaps and countercurrent extractions are demonstrated. The presented design significantly simplifies applications ranging from multistep synthesis to complex multistage separations.Novartis-MIT Center for Continuous ManufacturingUnited States. Defense Advanced Research Projects Agency (Grant N66001-11-C-4147

O2Activation over Ag-Decorated CeO2(111) and TiO2(110) Surfaces: A Theoretical Comparative Investigation

Periodic spin-polarized hybrid density functional theory calculations have been performed to investigate the reactivity of pristine, O-defective, and Ag-decorated CeO2(111) and TiO2(110) surfaces with a small Ag10 cluster toward O2. The adsorption of O2 and its subsequent dissociation have been studied in order to provide a better understanding of the role of the oxide, the metallic nanoparticle, and their interaction in the reactivity of composite metal/metal oxide materials toward O2, as potential catalysts to this reaction. Structural, energetic, electronic, and vibrational properties of all species involved in the different reaction paths considered have been fully characterized. On the stoichiometric surfaces, Ag10 is oxidized and reduces surface Ce4+/Ti4+ ions, while on the O-defective surfaces, the adhesion of silver is promoted only on CeO2 but unfavored on TiO2. On the other hand, on the silver-free supports, O2 strongly adsorbs at vacancies and preferentially reduces to peroxide. When no O vacancies are considered on the Ag10-decorated supports, the net positive charge on Ag10 actually prevents the adsorption and reduction of O2. Instead, when O vacancies are included, two reaction pathways are observed; oxygen molecules can weakly absorb on the silver cluster as a superoxide moiety or strongly adsorb at the vacancy as peroxide. The dissociation of the O-O bond of the peroxide is favored both from the thermodynamic and kinetic points of view in silver-decorated surfaces, in contrast with the silver-free cases. In addition, Ag10/CeO2 shows higher activity toward the O2 adsorption and dissociation than Ag10/TiO2, which can be related both to the higher ionicity and superior electron storage/release ability of ceria with respect to titania, thus leading to the weakening of the O-O bond and providing lower activation barriers for oxygen reduction. These results deepen the current understanding of the reactivity of metal/metal oxide composites toward O2, especially elucidating how the surface stoichiometry affects the charge state of the metal clusters, and hence the reactivity of these interfaces toward O2, with potential important consequences when such composites are considered for catalytic applications