Search results for "Modell"
showing 10 items of 2134 documents
Development of a Membrane Distillation module for solar energy seawater desalination
2012
Abstract Membrane Distillation (MD) processes are gaining growing interest among novel desalination technologies, in particular for small scale applications also coupled with non-conventional energy sources. In the present work an original laboratory scale planar geometry Membrane Distillation unit was designed, built and tested for future coupling with solar energy. Though conceptually simple, the original geometry was developed in order to allow for multi-stage arrangement, compactness, internal heat recovery and possible integration with a polymeric heat exchanger for final brine heating by means of solar energy or waste heat. The laboratory scale unit was tested in order to investigate …
Water losses dynamic modelling in water distribution networks
2015
In the last decades, one of the main concerns of the water system managers have been the minimisation of water losses, that frequently reach values of 30% or even 70% of the volume supplying the water distribution network. The economic and social costs associated with water losses in modern water supply systems are rapidly rising to unacceptably high levels. Furthermore, the problem of the water losses assumes more and more importance mainly when periods of water scarcity occur or when not sufficient water supply takes part in areas with fast growth. In the present analysis, a dynamic model was used for estimating real and apparent losses of a real case study. A specific nodal demand model …
A Refined Model for Knock Onset Prediction in Spark Ignition Engines Fueled With Mixtures of Gasoline and Propane
2015
In the last decade, gaseous fuels, such as liquefied petroleum gas (LPG) and natural gas (NG), widely spread in many countries, thanks to their prerogative of low cost and reduced environmental impact. Hence, bi-fuel engines, which allow to run either with gasoline or with gas (LPG or NG), became very popular. Moreover, as experimentally demonstrated by the authors in the previous works, these engines may also be fueled by a mixture of gasoline and gas, which, due to the high knock resistance of gas, allow to use stoichiometric mixtures also at full load, thus drastically improving engine efficiency and pollutant emissions with respect to pure gasoline operation without noticeable power los…
A Model for Capturing Product Assembly Information
2005
The important issue of mechanical assemblies has been a subject of intense research over the past several years. Most electromechanical products are assemblies of several components, for various technical as well as economic reasons. This paper provides an object-oriented definition of an assembly model called the Open Assembly Model (OAM) and defines an extension to the NIST Core Product Model (NIST-CPM). The assembly model represents the function, form, and behavior of the assembly and defines both a system level conceptual model and associated hierarchical relationships. The model provides a way for tolerance representation and propagation, kinematics representation, and engineering anal…
A predictive maintenance policy with imperfect monitoring
2010
For many systems,failure is a very dangerous or costly event. To reduce the occurrence of this event,it is necessary to implement a preventive maintenance policy to replace the critical elements before failure.Since elements do not often exhibit incipient faults, they are replaced before a complete exploiting of their useful life.To conjugate the objective of exploiting elements for almost all their useful life with the objective to avoid failure,condition based and,more recently,predictive maintenance policies have been proposed.This paper deals with this topic and proposes a procedure for the computation of the maintenance time that minimizes the global maintenance cost.By adopting a stoc…
How to formulate an accident prediction model for urban intersections.
2009
Several safety prediction models and methods have been developed to eliminate the relationship between the expected accident frequency and various urban intersection geometry and operational attributes. It is generally accepted that accident rates tend to be higher at intersections than on through sections of a road. This is particularly frequent in urban area where roads are characterized by intersections in close succession; moreover, the safe and effective operations of the urban road system can be significantly affected by safety conditions at intersections. In this paper models and methods designed to understand and to predict the accident process at urban intersections are reviewed. I…
Finite element modelling of slipage between FRP rebar and concrete in pull-out test
2014
The paper presents numerical results of direct pull-out test of glass fiber-reinforced polymer (GFRP) rebars embedded in concrete. Rebars of three different cross-sections are considered: circular without longitudinal ribs and with two and four ribs. The design analyses of the rebar configurations embedded in concrete are investigated by the 3D finite element method (FEM), which takes into account the non-linearity using ANSYS software. The results of the numerical model with two ribs were compared with the experimental results. Then, the effect of different rebar geometries to the load-slip pull-out curves was studied. It is concluded that the influence of rib height and width on the pull-…
Three-dimensional cardiac computational modelling: methods, features and applications
2015
[EN] The combination of computational models and biophysical simulations can help to interpret an array of experimental data and contribute to the understanding, diagnosis and treatment of complex diseases such as cardiac arrhythmias. For this reason, three-dimensional (3D) cardiac computational modelling is currently a rising field of research. The advance of medical imaging technology over the last decades has allowed the evolution from generic to patient-specific 3D cardiac models that faithfully represent the anatomy and different cardiac features of a given alive subject. Here we analyse sixty representative 3D cardiac computational models developed and published during the last fifty …
Surveying, Analysis and 3D Modeling in Archaeological Virtual Reconstruction. The inner colonnade of the naos of Temple G of Selinunte.
2012
This paper is focused on the virtual reconstruction of a portion of the naos of Temple G of Selinunte, as a case study for the definition of a method of virtual anastylosis and reconstruction of collapsed colonnades in archaeological contexts. Reconstruction is based on the combination of historical research, archaeological analysis, digital surveying, image-based modeling and laser scanning methods. The complexity of the ruins of the temple suggested a thorough archaeological analysis of the fragments of the inner colonnade of the naos. This analysis made it possible to identify reference surfaces and protective or sacrificial surfaces. The study of these surfaces, together with the dimens…
Dialoghi fra storia e disegno: il progetto di Enrico Del Debbio per la Casa del Balilla di Enna
2022
Attraverso il rapporto dialogico tra due diverse discipline afferenti al campo dell’architettura, come la storia e il disegno, in questo saggio si tenterà di indagare un’opera sconosciuta di Enrico Del Debbio, realizzata difformemente rispetto all’ipotesi progettuale: la Casa del Balilla per la città di Enna. Il progetto originario dell’architetto carrarese sarà ricostruito digitalmente a partire dall’esaustiva documentazione grafico-progettuale ritrovata presso il MAXXI di Roma. Un processo esegetico durante il quale si porterà alla luce un frammento finora inedito, quantunque infinitesimale della storia dell’architettura italiana, mediante l’applicazione combinata degli strumenti della Sc…