131,909 research outputs found
Se non ci credete non me ne importa
No full textNella postfazione si identificano e approfondiscono alcuni temi della raccolta Storie naturali
Pulse pressure affects the relationship between flow-mediated dilatation and cardiovascular risk
No full textEndothelial dysfunction is recognized as a pivotal factor in the development of atherosclerosis [1]. Dilatation of the brachial artery in response to an increase in flow (flow-mediated dilatation, FMD) during post-ischemic reactive hyperemia currently represents the most suitable approach for non-invasive assessment of endothelial functionFil: Cardona, Andrea. Universita Di Perugia; ItaliaFil: Ambrosio, Giuseppe. Universita Di Perugia; ItaliaFil: Mengoni, Anna. Universita Di Perugia; ItaliaFil: D´antonio, Antonella. Universita Di Perugia; ItaliaFil: Bentivoglio, Maurizio. Universita Di Perugia; ItaliaFil: Milei, Jose. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Investigaciones Cardiológicas (i); ArgentinaFil: Angeli, Fabio. Universita Di Perugia; Itali
The AGATA commissioning campaign at LNL
No full textThe one-year-long commissioning campaign of the AGATA Demonstrator, carried out at the Legnaro National Laboratories, is described, together with the main results achieved. The manuscript is dedicated to the memory of Enrico Farnea
Contract furniture design: an in-depth analysis to develop a competitive collaborative virtual environment
No full textContract Furniture market is a transversal business involving different types of products for diverse contexts of use representing an increasing competitive solution for Small and Medium-sized enterprises (SMEs). Although the well-known opportunities, contract furniture represents a quite unexplored field of research in terms of design methods and supporting tools. Collaboration in the contract cluster and web-enabling technologies, design automation and virtual prototyping of custom solutions are only a small set of relevant topics to be faced. In this context, the present paper investigates contract furniture by an in-depth analysis of AS-IS processes followed by 17 Italian companies operating in hospitality and retail and varying in size, skill, ICT expertise, organization and core business. Main research findings regard the formalization of contract furniture design processes, enabling technologies and main research challenges that need to be overcome and the definition of a TO- BE process model supported by an innovative web- based platform exploiting virtual prototyping techniques to enhance collaboration, process sustainability, negotiation and in general contract lifecycle management. The work contributes to improve a competitive sector that strongly differs from traditional product design and manufacturing, architecture and complex research projects involving multiple actors to achieve a common goal
A Web-Based platform to support contract furniture design
No full textContract furniture design is the process of creating finished commodities for hospitality, retail, store, office, restaurants, etc. According to the process stage, numerous stakeholders with different skills, abilities, background and interests are involved in the development of products and services. The management of these temporary networks is complex and requires proper computer-supported cooperative work platforms able to achieve coherent design solutions. The paper explores contract furniture design challenges and requirements to define a technological platform to support companies in market analysis and penetration, product configuration and team working. System architecture and its main software modules are described in detail and preliminary implementation results shown
An algorithmic approach to space vector modulation for multiphase inverters
No full textSince late 1990s multiphase drives have become a serious alternative to three-phase drives in some particular applications such as electric ship propulsion, locomotive traction, electric vehicles and high power industrial applications. Nowadays the research activity is focused on the development of control strategies that can exploit the degrees of freedom that exist in multiphase machines. As known, a multiphase motor cannot be analyzed using the space vector representation in a single d-q plane, but it is necessary to introduce multiple d-q planes.
In this paper the problem of the space vector modulation of multiphase inverters with an odd number of phases is solved introducing the concepts of reciprocal vector and adopting an algorithmic approach, i.e. the information on the inverter configurations, saved in a look-up table, is accessed on the basis of an iterative procedure. The proposed approach, confirmed by experimental tests, allows the full exploitation of the dc input voltage and the simultaneous modulation of voltage space vectors in different d-q planes
First Simulations on Higher-Efficiency Betavoltaic Battery Integrated with Electrets for Space, Medicine and Remote Sensing Applications
No full textThe results of Geant4 simulations using Montecarlo based code to explore suitable beta emitters and the interaction of beta rays with matter for the development of nuclear betavoltaic battery are shown. Such developments arise from the need of reliable, long-lived, high energy-density power sources for operating electrical systems in hostile and inaccessible environments, at variance with conventional electrochemical batteries with limited longevity and a strong tendency to degrade under extreme environmental conditions. The choice of beta emitters is due to the higher energy conversion efficiency and security when compared with other types of nuclear batteries. The geometrical efficiency of beta-particles interaction with different type of semiconductors is investigated
Seven-Phase Induction Motor Drive Based on Stator Flux Vector Control
No full textIn this paper, a rotor-flux-oriented control scheme for seven-phase induction motor drive, having the stator flux components instead of the stator current components as main control variables, is presented. As a consequence, a simple stator flux regulator can replace the conventional current regulators implemented in the synchronous reference frame.
The proposed Stator Flux Vector Control (SFVC) scheme uses a flexible modulation strategy for seven-phase Voltage Source Inverters (VSIs) that allows the simultaneous modulation of voltage space vectors in different d-q planes. This problem is completely solved using the Duty-Cycle Space Vector (DCSV) representation, which describes the state of the switches by means of complex variables. Using the DCSV representation it is possible to combine the multiple space vector representation, useful in modeling multi-phase machines, with traditional carrier-based PWM principle, suitable for the modulation of multi-phase VSIs.
The validity of the proposed control scheme is confirmed by experimental tests
Nuclear data activities at the n_TOF facility at CERN
No full textNuclear data in general, and neutron-induced reaction cross sections in particular, are important for a wide variety of research fields. They play a key role in the safety and criticality assessment of nuclear technology, not only for existing power reactors but also for radiation dosimetry, medical applications, the transmutation of nuclear waste, accelerator-driven systems, fuel cycle investigations and future reactor systems as in Generation IV. Applications of nuclear data are also related to research fields as the study of nuclear level densities and stellar nucleosynthesis. Simulations and calculations of nuclear technology applications largely rely on evaluated nuclear data libraries. The evaluations in these libraries are based both on experimental data and theoretical models. Experimental nuclear reaction data are compiled on a worldwide basis by the international network of Nuclear Reaction Data Centres (NRDC) in the EXFOR database. The EXFOR database forms an important link between nuclear data measurements and the evaluated data libraries. CERN's neutron time-of-flight facility n_TOF has produced a considerable amount of experimental data since it has become fully operational with the start of the scientific measurement programme in 2001. While for a long period a single measurement station (EAR1) located at 185 m from the neutron production target was available, the construction of a second beam line at 20 m (EAR2) in 2014 has substantially increased the measurement capabilities of the facility. An outline of the experimental nuclear data activities at CERN's neutron time-of-flight facility n_TOF will be presented. © 2016, The Author(s)
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