203 research outputs found

    Valorizzazione e tutela delle aree verdi periurbane per il recupero dell’identità culturale e della memoria storica del territorio

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    Il progetto di ricerca ha riguardato la progettazione di una greenway nel territorio comunale di Anzio e Nettuno al fine di comprendere come le aree verdi periurbane acquisiscono un ruolo di primaria importanza nell’ambito di attività di pianificazione territoriale. Esse infatti, in qualità di aree multifunzionali, consentono di innescare processi di riequilibrio dei flussi turistici e valorizzazione delle aree urbane. L’obiettivo principale del progetto si è concentrato sulla definizione di un’interazione dinamica tra sistemi sociali ed economici e sistemi ambientali basata su una funzione territoriale compatibile con gli obiettivi di tutela e delle risorse intendendo il territorio come substrato del processo di sedimentazione di valori storici, culturali e sociali.This research project focused on the design of a greenway in the municipality of Anzio and Nettuno in order to understand how green peri-urban areas acquire a role of primary importance within the activities of a territorial planning. As a matter of fact these multifunctional areas allow to trigger processes aimed at balancing tourist flows and enhancing urban areas. The project aims at defining a dynamic interaction between socio-economic and environmental systems based on a territorial function compatible with the objectives of protection of resources, being territory a substrate of the process of settling of historical, cultural and social values.Peer Reviewe

    Effect of ageing on carotid artery morphology, hemodynamics, and the development of atherosclerosis.

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    Cardiovascular diseases and ageing are two main challenges for health services. Cardiovascular disease is characterised by atherosclerosis, leading to heart attack and stroke. Atherosclerosis is a focal disease and occurs preferentially in regions of arterial bifurcation and curvature where complex flow features are observed. The carotid arteries represent a region of significant involvement in atherosclerosis. Previous studies have shown that haemodynamic factors are important determinants of the local distribution of atherosclerosis. However, longitudinal studies are lacking. The aim of this study was to investigate age-related changes in carotid artery morphology and haemodynamics based on longitudinal data acquired from a group of middle-aged subjects recruited to a cardiovascular disease prevention programme in Italy. The longitudinal study started in 1996 and participants were examined twice 12 years apart. All subjects underwent blood viscosity measurements and echo-Doppler examinations of the common carotid artery at baseline and follow-up. From the acquired ultrasound data, common carotid artery diameter, blood flow velocity, and intima-media thickness were measured, and wall shear stress, circumferential wall tension and Peterson elastic modulus were calculated. It was found that with ageing, blood viscosity increased, common carotid artery diameter increased, mean blood velocity and wall shear stress decreased, while intima-media thickness, circumferential wall tension and arterial stiffness increased. Interrelationships of the data were also examined: reductions in common carotid wall shear stress were independently associated with intima-media thickening. Furthermore, ageing-associated wall shear stress reduction predicted the development of atherosclerotic plaques, independently of known cardiovascular risk factors. In addition, in participants presenting shear stress reductions in only one side of the common carotid artery, development of atherosclerosis in the carotid tree was limited to the same body side. In conclusion, this longitudinal study confirms the role of arterial wall shear stress as a mediator of the effects of ageing on atherosclerosis.Open Acces

    Innovative Closed-Loop Recyclable Bio-Based Composites from Epoxidized Waste Flour and Recycled Carbon Fibers

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    Epoxy-based composites are designed for long-lasting applications, though their wide use is in contrast with their poor recyclability, which poses serious end-of-life issues. In order to reduce their environmental impact, precursors derived from fossil fuel based raw materials should be replaced with eco-friendly sources. This can be attained by using naturally derived epoxy matrices, or by finding a suitable solution for recycling at the end of life. In this paper, both strategies were analyzed, by replacing traditional monomers with epoxidized waste flour (EWF), an innovative bio-precursor derived from the organic waste stream, and a cleavable hardener, which allowed the recyclability of the matrix. The recyclable matrix was reinforced with recycled carbon fibers, derived from pyrolysis. DSC measurements were carried out in order to optimize the curing steps of the matrix, then flexural tests were performed in order to evaluate the mechanical response of the composite. A green recycling procedure was then investigated, which involved the use of non-toxic solvents and mild working conditions, and allowed recovery of the matrix while still preserving the properties of the carbon fibers. The components obtained after recycling were analyzed by FTIR analysis, which revealed the presence of the epoxy ring on the recycled waste flour. Hence, recycled waste flour was again used as a precursor and mixed with the cleavable hardener, thus, obtaining a closed-loop recycling

    Molecular-Level Switching of Polymer/Nanocrystal Non-Covalent Interactions and Application in Hybrid Solar Cells

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    Hy brid composites obtained upon blending conjugated polymers and colloidal inorganic semiconductor nanocrystals are regarded as attractive photo-active materials for optoelectronic applications. Here we demonstrate that tailoring nanocrystal surface chemistry permits to exert control on non-covalent bonding and electronic interactions between organic and inorganic components. The pendant moieties of organic ligands at the nanocrystal surface do not merely confer colloidal stability while hindering charge separation and transport, but drastically impact morphology of hybrid composites during formation from blend solutions. The relevance of our approach to photovoltaic applications is demonstrated for composites based on poly(3-hexylthiophene) and Pbs nanocrystals, considered as inadequate before the submission of this manuscript, which enable the fabrication of hybrid solar cells displaying a power conversion efficiency that reaches 3 %. Upon (quasi)steady-state and time-resolved analisys of the photo-induced processes in the nanocomposites and their organic and inorganic components, we ascertained that electron transfer occurs at the hybrid interface yielding long-lived separated charge carriers, whereas interfacial hole transfer appears slow. Here we provide a reliable alternative aiming at gaining control over macroscopic optoelectronic properties of polymer/nanocrystal composites by acting at the molecular-level via ligands' pendant moieties, thus opening new possibilities towards efficient solution-processed hybrid solar cells

    Blood Viscosity in Subjects With Normoglycemia and Prediabetes

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    OBJECTIVE Blood viscosity (BV) is higher in diabetic patients and might represent a risk factor for the development of insulin resistance and type 2 diabetes. However, data in subjects with normal glucose or prediabetes are missing. In the current study, we evaluated the relationship between BV and blood glucose in subjects with normal glucose or prediabetes. RESEARCH DESIGN AND METHODS Enrolled subjects were divided into three groups according to blood glucose: group A ( n = 74), blood glucose <90 mg/dL; group B ( n = 96), blood glucose ranging from 90 to 99 mg/dL; and group C ( n = 94), blood glucose ranging from 100 to 125 mg/dL. BV was measured at 37°C with a cone-plate viscometer at shear rates ranging from 225 to 22.5 s−1. RESULTS Blood pressure, blood lipids, fibrinogen, and plasma viscosity were similar in the three groups. BMI and waist circumference were significantly increased in group C. Hematocrit ( P < 0.05) and BV ( P between 0.01 and 0.001) were significantly higher in groups B and C compared with group A. Blood glucose was significantly and inversely correlated with HDL cholesterol and directly with BMI, waist, hematocrit ( r = 0.134), and BV (from 225 s−1 to 22.5 s−1; r ranging from 0.162 to 0.131). BV at shear rate 225 s−1 was independently associated with blood glucose. CONCLUSIONS The current study shows a direct relationship between BV and blood glucose in nondiabetic subjects. It also suggests that, even within glucose values considered completely normal, individuals with higher blood glucose levels have increased BV comparable with that observed in subjects with prediabetes

    Flexible distributed Bragg reflectors as optical outcouplers for OLEDs based on a polymeric anode

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    Top-emitting OLEDs (TOLEDs) represent a promising technology for the development of next-generation flexible and rollable displays, thanks to their improved light outcoupling and their compatibility with opaque substrates. Metal thin films are the most used electrodes for the manufacturing of TOLEDs, but they show poor resistance to mechanical deformation, which compromises the long-term durability of flexible devices. This paper reports the exploitation of a dielectric mirror (DBR) based on seven pairs of TiO2 and SiO2 combined with a polymeric electrode as an alternative to the bottom metal electrode in flexible TOLEDs. The DBR showed a maximum reflectivity of 99.9% at about 550 nm, and a stop-band width of about 200 nm. The reflectivity remained unchanged after bending and treatment with water and solvents. Green TOLED devices were fabricated on top of DBRs, and demonstrated good stability in terms of electro-optical and colorimetric characteristics, according to varying viewing angles. These results demonstrate that the combination of the flexible DBR with the polymeric anode is an interesting strategy for improving the durability of flexible TOLEDs for display applications, implemented on different kinds of free-standing ultra-thin substrates

    Generalized Poisson Difference Autoregressive Processes

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    This paper introduces a new stochastic process with values in the set Z of integers with sign. The increments of process are Poisson differences and the dynamics has an autoregressive structure. We study the properties of the process and exploit the thinning representation to derive stationarity conditions and the stationary distribution of the process. We provide a Bayesian inference method and an efficient posterior approximation procedure based on Monte Carlo. Numerical illustrations on both simulated and real data show the effectiveness of the proposed inference

    Markers of insulin resistance and carotid atherosclerosis. A comparison of the homeostasis model assessment and triglyceride glucose index.

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    Summary Aims The present investigation was designed to test the association between carotid atherosclerosis and two simple markers of insulin resistance, i.e. HOMA-Index and TyG-Index. Materials and methods The study was performed in two different cohorts. In the first cohort, 330 individuals were enrolled. Blood pressure, lipids, glucose, waist and cigarette smoking were evaluated. HOMA-IR and TyG-Index were calculated as markers of prevalent hepatic and muscular insulin resistance respectively. Carotid atherosclerosis was assessed by Doppler ultrasonography. The association between cardiovascular risk factors, markers of insulin resistance and carotid atherosclerosis was assessed by multiple logistic regression analyses. In the second cohort, limited to the evaluation of TyG-Index, 1432 subjects were studied. Results In the first cohort, TyG-Index was significantly associated with carotid atherosclerosis in a model including age, sex, diabetes, cigarette smoking and LDL cholesterol, while HOMA-IR was not. When components of metabolic syndrome were added to the model as dichotomous variables (absent/present), TyG-Index retained its predictive power. The same result was obtained when the metabolic syndrome was added to the model (absence/presence). The association between TyG-Index and carotid atherosclerosis was confirmed in the second cohort. Conclusions The present findings suggest that TyG-Index is better associated with carotid atherosclerosis than HOMA-IR

    The enhancement of excitonic emission crossing Saha equilibrium in trap passivated CH3NH3PbBr3 perovskite

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    Metal-halide semiconductor perovskites have received great attention for the development of stable and efficient light emitting diodes and lasers, since they combine high charge carrier mobility and light emission spectral-purity with low-cost fabrication methods. Nevertheless, the role of excitons, free carries and trap states in perovskite light emission properties is still unclear due to their interdependence. In this paper we selectively manage trapping and light emission mechanisms by a reversible laser-assisted trap-passivation process performed on a CH3NH3PbBr3 perovskite layer, coupled to the inner modes of a high-quality micro-cavity, which only affects the radiative recombination. We show that photoluminescence is dominated by exciton radiative decay process and that trap states passivation increases the exciton gemination rate by reducing coulombic scattering of free electrons due to the ionized impurities. This picture provides a more general description than the model based on trap states-free Saha thermodynamic equilibrium between photo-generated species. The interdependence of free carries, trap states and excitons in the light emission properties of CH3NH3PbBr3 perovskite thin films and their relationship to device performance is a subject of debate. Here, the authors investigate the role of non-radiative recombination and demonstrate that the photoluminescence is dominated by exciton radiative decay processes
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