Il paesaggio urbano e L'automobile nelle arre metropolitane di Belo Horizonte, Shanghai, Torino - Verso una nuova forma di integrazione tra trasporto privato e tessuto urbano

Partendo da una selezionata bibliografia di riferimento vengono analizzate le città di Belo Horizonte, Shanghai e Torino sulla base del rapporto tra paesaggio urbano e mobilità privata, narrando sia il punto di vista dell' automobile verso la città che il punto di vista della città verso l'automobile. Sulla base dei risultati ottenuti dall'analisi delle tre città campione si ipotizza un nuovo modello di mobilità privata, che non intende intervenire sulla struttura del tessuto urbano bensì sull'idea di automobil

Advertisement Delivery and Display in Vehicular Networks: Using V2V Communications for Targeted Ads

Advertisement delivery is expected to play a crucial role in future vehicular networks. In this paper, we address such a problem in vehicular networks, where advertisements (ads) can be broadcasted by roadside units (RSU) as well as vehicles, and then displayed to interested users. We describe the advertisement dissemination process by means of an optimization model that aims at maximizing the number of ads that users display within the target area and validity period of the ad. We then solve the optimization problem, obtaining the optimal scheduling strategy that RSUs and vehicles should adopt for ad broadcasting. Our study highlights the important role that vehicle-to-vehicle communication will have in ads delivery. Also, it shows how coexisting vehicular and cellular networks can effectively complement each other, with vehicular networks being a very efficient means for pervasive ad dissemination

RV longitudinal deformation correlates with myocardial fibrosis in patients with end-stage heart failure

Objectives This study was performed to determine the accuracy of right ventricular (RV) longitudinal strain (LS) in predicting myocardial fibrosis in patients with severe heart failure (HF) undergoing heart transplantation. Background RVLS plays a key role in the evaluation of its systolic performance and clinical outcome in patients with refractory HF. Methods We studied 27 patients with severe systolic HF (ejection fraction 25% and New York Heart Association functional class III to IV, despite full medical therapy and cardiac resynchronization therapy) using echocardiography before heart transplantation. RV free wall LS, right atrial LS, sphericity index (SI), and tricuspid annular plane systolic excursion (TAPSE) were all measured. Upon removal of the heart, from the myocardial histologic analysis, the ratio of the fibrotic to the total sample area determined the extent of fibrosis (%). Results RV myocardial fibrosis correlated with RV free wall LS (r = 0.80; p < 0.0001), SI (r = 0.42; p = 0.01) and VO max (r = -0.41; p = 0.03), with a poor correlation with TAPSE (r = -0.34; p = 0.05) and right atrial LS (r = -0.37; p = 0.03). Stepwise multivariate analysis showed that RV free wall LS (β = 0.701, p < 0.0001) was independently associated with RV fibrosis (overall model R= 0.64, p < 0.0001). RV free wall LS was the main determinant of myocardial fibrosis. In the subgroup of patients with severe RV fibrosis, RV free wall LS had the highest diagnostic accuracy for detecting severe myocardial fibrosis (area under the curve = 0.87; 95% confidence interval: 0.80 to 0.94). Conclusions In late-stage HF patients, the right ventricle is enlarged, with reduced systolic function due to significant myocardial fibrosis. RV free wall myocardial deformation is the most accurate functional measure that correlates with the extent of RV myocardial fibrosis and functional capacity

Reference values of right atrial longitudinal strain imaging by two-dimensional speckle tracking.

Background: The role of speckle tracking in the assessment of right atrial (RA) deformation dynamics has not been established yet. The reference ranges of RA longitudinal strain indices were measured by speckle tracking in a population of normal subjects. Methods: In 84 healthy individuals, peak atrial longitudinal strain (PALS), peak atrial contraction strain (PACS), and time to peak longitudinal strain (TPLS) were measured using a six-segment model for the RA. Strain rate (SR) was also measured starting from the QRS-wave onset, peak positive (x-wave), first peak negative (y-wave), and second negative peak (z-wave). The time from the QRS onset was measured to each wave peak. Results: Adequate tracking quality was achieved in 64% of segments analyzed. Inter- and intraobserver variability coefficients of measurements ranged between 6% and 11%. Global PALS was 49 ± 13%, global TPLS was 363 ± 59 msec, x-wave was 2.12 ± 0.58 sec−1, y-wave was −1.91 ± 0.63 sec−1, and z-wave was −2.18 ± 0.78 sec−1. Conclusion: Speckle tracking is a feasible technique for the assessment of longitudinal myocardial RA deformation. Reference ranges of strain indices were reported

Three-reactors chemical looping process for hydrogen production

This paper analyzes a novel process for producing hydrogen from natural gas, based on chemical looping (CL) techniques, allowing for intrinsic capture of carbon dioxide. The core of the process consists of a three-reactors CL system, where iron oxide particles are circulated to: (i) oxidize natural gas (thus providing, after cooling and water condensation, a CO2 stream ready for sequestration), (ii) reduce steam, to produce hydrogen as the final product of the process, (iii) consume oxygen from an air stream, to sustain the thermal balance of the system. The process is intrinsically very attractive, because it directly produces hydrogen and CO2 from natural gas, by means of a process simpler than the conventional technologies with CO2 capture capabilities. Hence, a significant potential for investment cost reduction can be anticipated. However, to fully exploit the system potential, an efficient energy recovery from the gaseous streams exiting the reactors must be arranged, taking into account power and steam production needed to support internal consumptions. Therefore, after an introduction clarifying the concept and the scope of the system, as well as its basic chemistry, this paper presents a discussion of two plant configurations, including different integration levels with power production (fired gas turbine (GT) vs. unfired turbocharger) and/or heat recovery steam production methods (also considering steam compression devices). A comparison with ‘‘proven technology’’ plants, based on steam reforming, is also carried out. Due to the lack of reliable estimates of the investment costs for components to be developed from scratch (CL reactors), the analysis is limited to the thermodynamic and technological aspects. Results show, however, that an impressive potential exists for CL systems for hydrogen production, thus deserving substantial R&D activities in the near future