7,664 research outputs found

    Ku & C Band solid state switch matrix for satellite payloads using LTCC multilayer substrate

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    This paper describes the design and development of Ku and C band solid state switch matrix for multimedia satellite payloads. The design, through the use of advanced packaging techniques, allows significant savings on mass and volume with respect to traditional electromechanical switches while guaranteeing a comparable reliability

    Using Augmented and Virtual Reality for teaching scientific disciplines

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    This paper aims at synthesizing the literature on the use of AR and VR for teaching scientific disciplines to identify strengths and weaknesses for student’s learning. Articles published in peer reviewed journals has been searched on Google Scholar from 2018. The results highlighted a great variety of studies’ methodology, field of applications, technology, target groups and outcomes. The growing interest in this topic is due to the emerging benefits for learning achievements, attitudes and motivations. Further studies are necessary to understand the type of technologies to be used in different contexts and to focus on learners’ characteristics, and its impact on learning outcomes. It is necessary to improve students’ and teachers’ digital competence, supporting them in designing educational intervention for the acquisition of scientific skills

    Transpulmonary pressure to guide mechanical ventilation: Art or science?

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    open3noNo abstract availableSupported in part by Progetti di Ricerca di Interesse Nazionale (PRIN 2017, project J4BE7A) of the Italian Minister of Education, University, and Research.openRanieri V.M.; Tonetti T.; Nava S.Ranieri V.M.; Tonetti T.; Nava S

    Long term therapeutic efficacy of a soft monobloc mandibular advancement device in adults with obstructive sleep apnea

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    To evaluate the long term (48 months) therapeutic efficacy of a soft monobloc mandibular advancement device in adult patients with mild or moderate obstructive sleep apnea

    Extracorporeal membrane oxygenation as "bridge" to lung transplantation: what remains in order to make it standard of care?

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    Since its introduction into clinical practice, lung transplantation (LTx) is gradually becoming a worldwide standard treatment for patients with a broad spectrum of end-stage respiratory diseases (1\u20133). From 1995 to 2010, more than 30,000 LTx have been performed, and it is worth noting that in recent years the number of LTx has been progressively increasing to more than 3,000/year in 2010, with a post-transplant graft half-life that went from 4.7 in the 1990s to 5.9 in the new millennium (4). However, the crude mortality rate of patients awaiting LTx is higher than mortality for other solid organs. Mortality rate in 2009 for patients on the waiting list for LTx was about 14.1% in North America (www.srtr.org) and 14.7% in Italy (www.airt.it). What are the reasons for these unacceptable mortality rates? First, patients have to wait for the graft longer than patients waiting for other organs because of the small number of lungs suitable for transplantation (5). Second is the lack of supportive therapies that are able to replace respiratory function when the primary pulmonary diseases evolve from \u201crespiratory insufficiency\u201d to \u201crespiratory failure,\u201d characterized by refractory hypoxemia and hypercapnia

    Optimal planning of safety improvements on road sites belonging to different categories within large networks: An integrated multi-layer framework

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    Planning road safety interventions on large road networks implies several layers of complexity in the decision-making process. In fact, the following simultaneous problems should be addressed: estimating safety performances on the different road elements of the network, identifying sites showing high potential for improvement with respect to reference values, defining the possible types of safety measures to be implemented and their anticipated effect on traffic safety, limiting the number of interventions given fixed budget constraints. This study proposes an integrated multi-layer framework which takes into account the above-defined problems into a single optimization procedure which provides the number and type of safety interventions to be implemented over a wide road network composed of different categories of road elements. The proposed framework is based on the following peculiar aspects: the potential for safety improvement is quantitatively assessed based on the estimation of safety performances for each road category, a bi-level thresholding process integrated in the optimization process is used to highlight sites for interventions, the anticipated outcome of safety measures is quantitatively assessed as well through available crash reduction factors. The proposed methodology is applied to a case study which analyzes a sample of real roads belonging to a province-wide road network composed of various road elements (i.e., different categories of segments and intersections), under different budget constraints. Results demonstrate the applicability and flexibility of the proposed approach, which could be used for planning purposes, independently of the particular geographic location. Clearly, the approach is valid at the planning stage, given that several details of the different layers of analysis are necessarily simplified, while they should be studied in detail at the single intervention project stage

    Effects of Berlin speed cushions in urban restricted speed zones: a case study in Bari, Italy

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    The widespread European policy towards urban sustainable mobility requires some engineering-related interventions on the existing urban road network, such as traffic calming measures. There is a substantial amount of research assessing the effects of different traffic calming measures, even if there is no unanimous evidence for some of them, such as speed cushions (in particular Berlin speed cushions). Some research on speed cushions has been conducted, even if different results were achieved, also varying with the country and context of installation. Moreover, some of these studies are old and they need to be updated, given the continuous transformation of urban environments. In agreement with the City of Bari, thanks to ASSET-Puglia Region funds, the Italian Ministry of Infrastructures and Transport has granted permission to install speed cushions on three urban streets located in restricted speed zones (≤30 km/h) in the City of Bari, to test their effects on vehicular traffic. In this context, this article is aimed at assessing the preliminary results obtained, considering the effects on vehicular speeds. The study design is a typical before-and-after study, in which speeds are measured using a laser speed gun on the three selected road segments before and after the implementation of speed cushions (for each segment, the cushion has a different width). Visual observations were also useful to detect the effects of speed cushions on trajectories and speeds of two-wheeled vehicles. The preliminary analysis of speed profiles revealed a consistent decrease in speed for all the three test sites (in particular the operating speed V85, which is reduced by up to approximately 30%). Moreover, it seems that the decrease in speed is more evident as the cushion width decreases
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