Design and experimental validation of Convex Conformal Reflectarray Antennas

In this work the design, the numerical analysis and the experimental characterization of a Convex conformal Reflectarray (CRA) has been carried out, with the aim of investigating the feasibility of reflectarrays bent on convex curved surfaces. A medium-size offset CRA in Ka-band has been designed, and a demonstrator has been manufactured and measured. The results prove the correctness of the design procedure and the feasibility of this type of antenna, pointing out the differences, also in terms of radiation performances, with respect to a planar reflectarra

Understanding Engagement and Willingness to Speak Up in Social Television: A Full-Season, Cross-Genre Analysis of TV Audience Participation on Twitter

The widespread use of digital platforms has changed the way people watch television. Despite an abundance of empirical studies, full-season, cross-genre analyses of different TV formats are rare. Based on a data set of 1,383,414 tweets, this study aims to close this gap by comparing Twitter commentaries around the 2012–2013 seasons of the Italian edition of The X Factor and the political talk show Servizio Pubblico. For each episode, we identify peaks of Twitter engagement and analyze the corresponding TV scene, revealing the role played by suspense and surprise in catalyzing the engagement of online audiences. A content analysis of 12,640 tweets created during peaks of engagement reveals how willingness to speak up varies when the topic is politics rather than entertainment

Reflectarray Antennas printed on convex surfaces

The characteristics of Reflectarray Antennas printed on convex curved surfaces are discussed in this paper. In particular, results will be presented on the radiation performances of Reflectarrays designed to fit cylinders with different radii of curvature, and with different types of radiating elements

Global longitudinal strain at rest predicts significant coronary artery stenosis in patients with peripheral arterial disease

Abstract Funding Acknowledgements Type of funding sources: None. Background Critical peripheral artery disease (PAD) is expression of systemic chronic atherosclerosis, it being often associated with cardiovascular events. The assessment of global longitudinal strain (GLS) at rest by speckle tracking echocardiography could be useful to unmask significant coronary artery disease (CAD) in asymptomatic PAD patients. Purpose To determine whether resting GLS is able to predict significant coronary artery stenosis in PAD patients selected for peripheral or carotid angiography. Methods One-hundred three clinically relevant PAD patients (M/F = 76/27, age = 66.8 ± 10,2 years, 72 with significant lower limb artery stenosis and 31 with carotid artery stenosis ≥50%), asymptomatic for CAD, underwent standard echo-Doppler exam at rest, comprehensive of GLS analysis, prior peripheral and coronary angiography. Information on cardiovascular (CV) risk factors and comorbidities were collected. Patients with know CAD and previous myocardial infarction, left ventricular (LV) ejection fraction < 50% and inadequate echocardiographic imaging were excluded. According to the results of coronary angiography, patients were divided in two groups: with significant coronary artery stenosis (>50% of obstruction. n = 73) and without significant coronary artery lesions (n = 30). Results No intergroup difference in the prevalence of CV risk factors and comorbidities was found. Age, body mass index and blood pressure were comparable between the two groups. LV ejection fraction (59.9 ± 4.2% in patients with significant coronary stenosis vs. 60.2 ± 4.7% in those without coronary stenosis, p = 0.75) and wall motion score index (1.02 ± 0.09 vs 1.03 ± 0.09 respectively, p = 0.67) did not differ significantly. Conversely, GLS was lower in patients with significant coronary artery stenosis than in those without (21.6 ± 2.7% vs. 22.8 ± 2%, p < 0.02) (Figure 1). This difference remained significant comparing the carotid subgroup with coronary stenosis vs. those without (p < 0.05) whereas it did not achieve the statistical significance in patients with lower limb artery lesions (p = 0.42). Conclusion In PAD patients, GLS at rest shoes the capability in identifying patients at higher probability of significant coronary artery stenosis. This involves in particular patients with carotid artery stenosis. GLS might be helpful to select patients who need to extend the peripheral angiographic evaluation to the coronary tree