2,579 research outputs found
Hadronic physics with KLOE
No full textF. Ambrosino et al. 2009. 8pp.
Prepared for 23th Les Rencontres de Physique de La Vallee d'Aoste, La Thuile, Aosta Valley, Italy, 1-7 Mar 2009.
Published in Nuovo Cim.C32N5-6:129-136,2009. Also in *La Thuile 2009, Results an
Drawing for Placemaking
No full textAllestimento mostra “Drawing for Placemaking” (4-18 novembre 2022) a cura di M. Ascolese, F. Iarrusso, V. Saitto con N. Ambrosino, P. Buccaro, F. Casalino, L. Esposito, M. Masi, C. Priore, M. Russo presso l’ambulacro di Palazzo Gravina – Facoltà di Architettura, via Monteoliveto 3, Napoli
Entrained-flow gasification of coal under slagging conditions: Relevance of fuel-wall interaction and char segregation to the properties of solid wastes
No full textEntrained-flow slagging gasifiers are characterized by operating conditions that promote ash migration/ deposition onto the reactor walls, whence ash is drained as a molten phase. Experimental investigation on ashes generated by full-scale plants suggested that both char entrapment inside the melt and carboncoverage of the slag can occur. Because of the wide range of spatial and temporal scales involved in these phenomena, numerical simulation of the fate of the flying fine char particles is a very difficult task. This work illustrates how different numerical modeling approaches can be jointly used to understand segregation patterns of char particles in full-scale entrained-flow coal gasifiers operated in the slagging regime. A multilevel approach has been developed for this purpose. RANS-based simulations of the full-scale geometry with coal particle injection and tracking aimed to obtain the general behavior of the flow field and particle trajectories. Simulations enabled to estimate the effect of swirl and tangential flow on the bulk-to-wall char particle deposition rate. Then, RANS results were adopted in a more detailed numerical model based on the solution of the filtered Navier-Stokes equations. In this last model, a turbulence LES approach for the Eulerian gas phase was applied. The equations of particles motion were solved via a Lagrangian particle tracking algorithm with the TrackToFace method. Simulations were performed involving a level of detail that allowed to obtain a clear picture of the multiphase flow behavior responsible for char deposition phenomena. This multilevel approach enabled the assessment of the char particle deposition rates and the nature of char-slag interaction (segregation/entrapment) that are likely to occur in full-scale slagging gasifiers. Results of numerical simulations have been critically discussed in the light of experimental findings. They represent a useful source of information for the implementation of constitutive equations and parameters in design-oriented reduced compartmental models. © 2013 Elsevier Ltd. All rights reserved
A virtual prototyping platform to improve CAE analysis workflow
No full textThis paper describes an experimental software system that allows interfacing a virtual immersive environment with Computer Aided Engineering (CAE) open source software aiming for improving and simplifying design process and results evaluation. System includes a middleware to execute jobs on HPC architectures and to compare results of server-class processors with GPGPU hardware. The main innovation of the overall system is the possibility to setup the CAE job directly inside the virtual reality platform speeding-up the entire process. User evaluations on selected case studies show how the use of a virtual environment may enhance the perception of engineers ideas during the design process. In addition, the use of a system that allows reconfiguring and relaunching the job simplifies setup of job configuration. Results also show that HPC hardware based on GPGPU offers a perceivable speedup for problems with an high number of nodes. © 2015, Springer International Publishing Switzerland
A case study on possible radiological contamination in the Lo Uttaro landfill site (Caserta, Italy)
No full textThe prevention of radioactive pollution is a primary objective of environmental protection codes in the operation of solid waste landfill activities. Several studies have demonstrated the effectiveness of radiological monitoring of the main constituents of urban landfill waste. The present contribution reports on an investigation plan carried out to evaluate the possible radiological contamination in the municipal landfill Lo Uttaro, district of Caserta (Italy). The investigation focused primarily on the perimeter area of the landfill in order to assess the possible impact on the surrounding population. The results of measurements of the equivalent dose rate along the perimeter of the landfill show average values lower than the population dose limit due to natural background radiation. Several samples of soil, groundwater and leachate representative of the subsoil of the study area were collected and the radionuclides were measured by gamma spectrometry. The results of these measurements show the absence of artificial radionuclides, except for small amounts of 137Cs due to nuclear disasters occurring in the last 50 years on Earth, and the mere presence of 40K and other natural radionuclides belonging to natural radioactive chains of 238U, 235U and 232Th
Etno-Graphs. The (textural, graphical, photographical) transcription of field observation as a specific pratice of architectural ethnography
No full textAllestimento mostra “Etno-Graphs. The (textural, graphical, photographical) transcription of field observation as a specific pratice of architectural ethnography” (22-26 maggio 2023) a cura di G. Postiglione, P. Briata, V. Saitto con N. Ambrosino, P. Buccaro, F. Casalino, L. Esposito, M. Masi, C. Priore, M. Russo presso l’ambulacro di Palazzo Gravina – Facoltà di Architettura, via Monteoliveto 3, Napoli
Real-time Detectors for Muography
No full textDifferent types of detectors can be used for muon radiography. Common to all detectors is the ability to track the direction of the incoming muon. Emulsion detectors have very high resolution and no need for electric power, but cannot give real-time information and cannot be used in all environmental conditions. Detectors with electronic readout have generally lower resolution but are more flexible, can be operated in real-time, and can also measure the time of the muon hitting the detector with resolutions as low as few hundred ps in specific setups. Special geometries and assemblies have been used for specific applications, where the size, weight, or shape of the detector are heavily constrained
Una rilettura sistemico vitale delle relazioni socio-saniatarie in Campania. Il caso del Centro Penitenziario Secondigliano
No full textStability and instability conditions using polyhedral Lyapunov functions
No full textIn this article, the authors study the robustness analysis problem for linear continuous-time systems subject to parametric time-varying uncertainties making use of piecewise linear (polyhedral) Lyapunov functions. A given class of Lyapunov functions is said to be 'universal' for the uncertain system under consideration if the search of a Lyapunov function that proves the robust stability of the system can be restricted, without conservatism, to the elements of the class. In the literature, it has been shown that the class of polyhedral functions is universal, while, for instance, the class of quadratic Lyapunov functions is not. This fact justifies the effort of developing efficient algorithms for the construction of optimal polyhedral Lyapunov functions. In this context, the authors provide a novel procedure that enables to construct, in the general n-dimensional case, a polyhedral Lyapunov function to prove the robust stability of a given system. Some numerical examples are included, where the authors show the effectiveness of the proposed approach comparing it with other approaches proposed in the literature
A convex condition for robust stability analysis via polyhedral Lyapunov functions
No full textIn this paper we study the robustness analysis problem for linear continuous-time systems subject to parametric time-varying uncertainties making use of piecewise linear (polyhedral) Lyapunov functions. A given class of Lyapunov functions is said to be "universal" for the uncertain system under consideration if the robust stability of the system is equivalent to the existence of a Lyapunov function belonging to the class. In the literature it has been shown that the class of polyhedral functions is universal, while, for instance, the class of quadratic functions is not. This fact justifies the effort of developing efficient algorithms for the construction of polyhedral Lyapunov functions. In this context, we provide a low computational cost procedure, based on a novel convex condition, for the construction of a polyhedral Lyapunov function. In the section on the numerical examples, we consider some benchmark problems for the robust stability analysis and we show that the proposed low computational cost approach, though only sufficient, is less conservative than all the other approaches presented so far in the literature
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