The quantum-classical transition in thermally seeded parametric downconversion

We address the pair of conjugated field modes obtained from parametric-downconversion as a convenient system to analyze the quantum-classical transition in the continuous variable regime. We explicitly evaluate intensity correlations, negativity and entanglement for the system in a thermal state and show that a hierarchy of nonclassicality thresholds naturally emerges in terms of thermal and downconversion photon number. We show that the transition from quantum to classical regime may be tuned by controlling the intensities of the seeds and detected by intensity measurements. Besides, we show that the thresholds are not affected by losses, which only modify the amount of nonclassicality. The multimode case is also analyzed in some detail.Comment: 12 pages, 3 figure

The quantum-classical transition in thermally seeded parametric downconversion

We address the pair of conjugated field modes obtained from parametric-downconversion as a convenient system to analyze the quantum-classical transition in the continuous variable regime. We explicitly evaluate intensity correlations, negativity and entanglement for the system in a thermal state and show that a hierarchy of nonclassicality thresholds naturally emerges in terms of thermal and downconversion photon number. We show that the transition from quantum to classical regime may be tuned by controlling the intensities of the seeds and detected by intensity measurements. Besides, we show that the thresholds are not affected by losses, which only modify the amount of nonclassicality. The multimode case is also analyzed in some detail.Comment: 12 pages, 3 figure

Avalanche Photo-Detection for High Data Rate Applications

Avalanche photo detection is commonly used in applications which require single photon sensitivity. We examine the limits of using avalanche photo diodes (APD) for characterising photon statistics at high data rates. To identify the regime of linear APD operation we employ a ps-pulsed diode laser with variable repetition rates between 0.5MHz and 80MHz. We modify the mean optical power of the coherent pulses by applying different levels of well-calibrated attenuation. The linearity at high repetition rates is limited by the APD dead time and a non-linear response arises at higher photon-numbers due to multiphoton events. Assuming Poissonian input light statistics we ascertain the effective mean photon-number of the incident light with high accuracy. Time multiplexed detectors (TMD) allow to accomplish photon- number resolution by photon chopping. This detection setup extends the linear response function to higher photon-numbers and statistical methods may be used to compensate for non-linearity. We investigated this effect, compare it to the single APD case and show the validity of the convolution treatment in the TMD data analysis.Comment: 16 pages, 5 figure

Has VZV epidemiology changed in Italy? Results of a seroprevalence study

The aim of the study was to evaluate if and how varicella prevalence has changed in Italy. In particular a seroprevalence study was performed, comparing it to similar surveys conducted in pre-immunization era. During 2013–2014, sera obtained from blood samples taken for diagnostic purposes or routine investigations were collected in collaboration with at least one laboratory/center for each region, following the approval of the Ethics Committee. Data were stratified by sex and age. All samples were processed in a national reference laboratory by an immunoassay with high sensitivity and specificity. Statutory notifications, national hospital discharge database and mortality data related to VZV infection were analyzed as well. A total of 3707 sera were collected and tested. In the studied period both incidence and hospitalization rates decreased and about 5 deaths per year have been registered. The seroprevalence decreased in the first year of life in subjects passively protected by their mother, followed by an increase in the following age classes. The overall antibody prevalence was 84%. The comparison with surveys conducted with the same methodology in 1996–1997 and 2003–2004 showed significant differences in age groups 1–19 y. The study confirms that in Italy VZV infection typically occurs in children. The impact of varicella on Italian population is changing. The comparison between studies performed in different periods shows a significant increase of seropositivity in age class 1–4 years, expression of vaccine interventions already adopted in some regions

Impacts of safety on the design of light remotely-piloted helicopter flight control systems

This paper deals with the architecture definition and the safety assessment of flight control systems for light remotely-piloted helicopters for civil applications. The methods and tools to be used for these activities are standardised for conventional piloted aircraft, while they are currently a matter of discussion in case of light remotely-piloted systems flying into unsegregated airspaces. Certification concerns are particularly problematic for aerial systems weighing from 20 to 150 kgf, since the airworthiness permission is granted by national authorities. The lack of specific requirements actually requires to analyse both the existing standards for military applications and the certification guidelines for civil systems, up to derive the adequate safety objectives. In this work, after a survey on applicable certification documents for the safety objectives definition, the most relevant functional failures of a light remotely-piloted helicopter are identified and analysed via Functional Hazard Assessment. Different architectures are then compared by means of Fault-Tree Analysis, highlighting the contributions to the safety level of the main elements of the flight control system (control computers, servoactuators, antenna) and providing basic guidelines on the required redundancy level

Access to Healthcare as a New Commons: Telemedicine as a Strategy for Providing Value-Based Healthcare Services in Rural Areas

Commons is a general term that refers to a resource shared by a group of people. Over the years, scholars have identified two generations of commons. The first generation of commons was about sharing of physical things; the second one is about intangible commons pool resources such as science and culture. These generally can be recognized as "rights" (Hess 2008). Among the various New Commons sectors there is medical and health. In the perspective of guaranteeing the right of Health, the ―Access to Healthcare‖ could be considered as a New Commons provided by worldwide National Healthcare Systems (NHS), However, healthcare sector is characterized by plenty of stakeholders with myriad, often, conflicting goals. The value-based approach (Porte, 2010) attempts to introduce a new universal language in healthcare management around the value for the patient that reconcile all stakeholders‘ interests. The goal of this approach is to improve the outcome and increase the number of treatments. This aim is very difficult to be enriched for rural residents; when patients live in remote areas, providing them with valuable medical care can be considered a hard challenge for the NHS, which has to be addressed also by the employment of new healthcare strategies and technologies. Defined as "a new healthcare delivery process provided when patient and professional are not physically in the same place" (Italian Ministry of Health, 2014), telemedicine could be seen as an answer to this challenge. Accordingly, this study aims at discovering if telemedicine employment can be effectively considered as a successful strategy to improve healthcare in location far from specialized hospital, enhancing the New Commons ―Access to care‖. A statistical-based narrative review of the literature was conducted in the field of telemedicine, with the aim to understand which experiences of telemedicine applications have got successful results as support of healthcare delivering in rural locations. With regards to rural and remote areas, several Authors recognized telemedicine-based strategies as a method to facilitate the access to healthcare in different medical disciplines. In particular, many studies highlight that telemedicine improves patient care by increasing the capacity of the rural clinician to manage patient locally, minimizing time away to support networks and reducing unnecessary transfers. Telemedicine could also be considered a cost-effective method whose outcomes remain similar (if not better) in quality to ―staffed‖ services, whose infrastructural costs could be easily paid-back

Enhanced Scattering by Wearable Objects in Wireless Power Transfer Links: Case Studies

Wireless power transfer (WPT) systems have ushered in a new era for wearable and implantable technologies, introducing opportunities for enhanced device functionality. A pivotal aspect in improving these devices is the optimization of electromagnetic transmission. This paper presents several solutions to improve electromagnetic transmission to an implantable/wearable device. Several scatterers are considered to mimic objects that can be easily worn by a patient, such as necklaces and bracelets, or easily integrated into textile fabric. An analytical method is employed to address the scattering by cylindrical objects above a biological tissue, modeled as a multilayer. Expansions into cylindrical waves, also represented through plane-wave spectra, are used to express the scattered fields in each medium. Numerical results for both the case of conducting and of dielectric cylindrical scatterers are presented at a frequency of the Industrial, Scientific and Medical band ((Formula presented.) GHz), showing possible configurations of worn objects for electromagnetic field intensification

Development of a simulation platform of all-electric aircraft on-board systems for energy management studies

This paper deals with the development of a simulation platform for the dynamic analysis of systems characterised by different physical domains. The research has been carried out in the context of the EC-funded Clean Sky Joint Technology Initiative (Green Regional Aircraft/All-Electric Aircraft domain). In particular, the objective of the research is focused on the on-board systems of new All-Electric Aircraft, where a crucial design point is related to the electrical energy management. In the “all-electric” concept, where pneumatic and hydraulic power systems are eliminated to improve aviation costs and environmental impact, the dynamics of electrical power absorptions is to be characterised and managed to avoid excessive peaks with respect to generators capabilities. The paper describes the architecture of a Matlab/Simulink simulation platform developed in order to design and validate of the electrical energy management logics, which lead up to 32% reduction of the maximum power request for the case study considered. Thanks to an approach based on a mixing of cosimulation and S-function compiling, the platform integrates models coming from different environments (AMESim, Dymola/Modelica), and developed by various partners/specialists

A nature-based system for improving Mediterranean buildings’ performance: contribution to energy saving by heat transfer reduction and influence of climatic parameters

Urban environments can be turned greener and more sustainable by letting in vegetation. Applying green facades on buildings’ vertical surfaces is a viable option that brings various advantages. This study focuses on the energy benefit provided by an evergreen green facade in Mediterranean climate conditions. The results came from a long experimental campaign, heat fluxes evaluation, and statistical analyses. The thermal behaviour of the experimental green facade was analysed all year round, highlighting differences between warm and cold periods and the time of the day. The main advantage was assessed in terms of energy saving, defined as heat flux reduction through the wall covered with vegetation compared to an unvegetated wall. The study pointed out that energy saving was achieved throughout the year, but at different times of the day based on the season. A daytime energy saving was obtained in warm periods due to the shading effect and the plants’ evapotranspiration. A night-time benefit was reached in cold periods mainly thanks to the green layer’s thermal and wind barrier action. The results showed daily mean energy saving values equal to 11.47 W m-2 for a warm period and 3.23 W m-2 for a cold period. The statistical analysis highlighted that the energy saving was positively influenced by external air temperature, especially in the daytime. Overall, higher energy saving was provided by the green facade when higher external air temperature values were recorded. This research contributes to filling existing literature gaps on the yearly behaviour of green facades and on the energy benefits these provide. use only

Implementing a GIS-Based Digital Atlas of Agricultural Plastics to Reduce Their Environmental Footprint: Part II, an Inductive Approach.

Plastic pollution, largely perceived by the public as a major risk factor that strongly impacts sea life and preservation, has an even higher negative impact on terrestrial ecosystems. Indeed, quantitative data about plastic contamination on agricultural soils are progressively emerging in alarming ways. One of the main contributors to this pollution involves the mismanagement of agricultural plastic waste (APW), i.e., the residues from plastic material used to improve the productivity of agricultural crops, such as greenhouse covers, mulching films, irrigation pipes, etc. Wrong management of agricultural plastics during and after their working lives may pollute the agricultural soil and aquifers by releasing macro-, micro-, and nanoplastics, which could also enter into the human food chain. In this study, we aimed to develop a methodology for the spatial quantification of agricultural plastics to achieve sustainable post-consumer management. Through an inductive approach, based on statistical data from the agricultural census of the administrative areas of the Italian provinces, an agricultural plastic coefficient (APC) was proposed, implemented, and spatialized in a GIS environment, to produce a database of APW for each type of crop. The proposed methodology can be exported to other countries. It represents valuable support that could realize, in integration with other tools, an atlas of agricultural plastics, which may be a starting point to plan strategies and actions targeted to the reduction of the plastic footprint of agriculture