Ricerca ed applicazione di nuovi metodi di progettazione meccanica e di industrial design

The present dissertation relates to methodologies and technics about industrial and mechanical design. The author intends to give a complete idea about the world of design, showing the theories of Quality Function Deployment and TRIZ, of other methods just like planning, budgeting, Value Analysis and Engineering, Concurrent Engineering, Design for Assembly and Manufactoring, etc., and their applications to five concrete cases. In these cases there are also illustrated design technics as CAD, CAS, CAM; Rendering, which are ways to transform an idea into reality. The most important object of the work is, however, the birth of a new methodology, coming up from a comparison between QFD and TRIZ and their integration through other methodologies, just like Time and Cost Analysis, learned and skilled during an important experience in a very famous Italian automotive factory.

Sorveglianza dell'influenza aviare: studio di un sistema di rilevazione precoce della circolazione virale in popolazioni di volatili selvatici

The emergency of infection by highly pathogenic avian influenza virus (HPAI) subtype H5N1 has focused the attention of the world scientific community, requiring the prompt provision of effective control systems for early detection of the circulation of low pathogenic influenza H5 viruses (LPAI) in populations of wild birds to prevent outbreaks of highly pathogenic (HPAI) in populations of domestic birds with possible transmission to humans. The project stems from the aim to provide, through a preliminary analysis of data obtained from surveillance in Italy and Europe, a preliminary study about the virus detection rates and the development of mathematical models, an objective assessment of the effectiveness of avian influenza surveillance systems in wild bird populations, and to point out guidelines to support the planning process of the sampling activities. The results obtained from the statistical processing quantify the sampling effort in terms of time and sample size required, and simulating different epidemiological scenarios identify active surveillance as the most suitable for endemic LPAI infection monitoring in wild waterfowl, and passive surveillance as the only really effective tool in early detecting HPAI H5N1 circulation in wild populations. Given the lack of relevant information on H5N1 epidemiology, and the actual finantial and logistic constraints, an approach that makes use of statistical tools to evaluate and predict monitoring activities effectiveness proves to be of primary importance to direct decision-making and make the best use of available resources.

Metodi di ottimizzazione morfologica nel progetto preliminare di propulsori aeronautici avanzati

The aim of this Doctoral Thesis is to develop a genetic algorithm based optimization methods to find the best conceptual design architecture of an aero-piston-engine, for given design specifications. Nowadays, the conceptual design of turbine airplanes starts with the aircraft specifications, then the most suited turbofan or turbo propeller for the specific application is chosen. In the aeronautical piston engines field, which has been dormant for several decades, as interest shifted towards turboaircraft, new materials with increased performance and properties have opened new possibilities for development. Moreover, the engine’s modularity given by the cylinder unit, makes it possible to design a specific engine for a given application. In many real engineering problems the amount of design variables may be very high, characterized by several non-linearities needed to describe the behaviour of the phenomena. In this case the objective function has many local extremes, but the designer is usually interested in the global one. The stochastic and the evolutionary optimization techniques, such as the genetic algorithms method, may offer reliable solutions to the design problems, within acceptable computational time. The optimization algorithm developed here can be employed in the first phase of the preliminary project of an aeronautical piston engine design. It’s a mono-objective genetic algorithm, which, starting from the given design specifications, finds the engine propulsive system configuration which possesses minimum mass while satisfying the geometrical, structural and performance constraints. The algorithm reads the project specifications as input data, namely the maximum values of crankshaft and propeller shaft speed and the maximal pressure value in the combustion chamber. The design variables bounds, that describe the solution domain from the geometrical point of view, are introduced too. In the Matlab® Optimization environment the objective function to be minimized is defined as the sum of the masses of the engine propulsive components. Each individual that is generated by the genetic algorithm is the assembly of the flywheel, the vibration damper and so many pistons, connecting rods, cranks, as the number of the cylinders. The fitness is evaluated for each individual of the population, then the rules of the genetic operators are applied, such as reproduction, mutation, selection, crossover. In the reproduction step the elitist method is applied, in order to save the fittest individuals from a contingent mutation and recombination disruption, making it undamaged survive until the next generation. Finally, as the best individual is found, the optimal dimensions values of the components are saved to an Excel® file, in order to build a CAD-automatic-3D-model for each component of the propulsive system, having a direct pre-visualization of the final product, still in the engine’s preliminary project design phase. With the purpose of showing the performance of the algorithm and validating this optimization method, an actual engine is taken, as a case study: it’s the 1900 JTD Fiat Avio, 4 cylinders, 4T, Diesel. Many verifications are made on the mechanical components of the engine, in order to test their feasibility and to decide their survival through generations. A system of inequalities is used to describe the non-linear relations between the design variables, and is used for components checking for static and dynamic loads configurations. The design variables geometrical boundaries are taken from actual engines data and similar design cases. Among the many simulations run for algorithm testing, twelve of them have been chosen as representative of the distribution of the individuals. Then, as an example, for each simulation, the corresponding 3D models of the crankshaft and the connecting rod, have been automatically built. In spite of morphological differences among the component the mass is almost the same. The results show a significant mass reduction (almost 20% for the crankshaft) in comparison to the original configuration, and an acceptable robustness of the method have been shown. The algorithm here developed is shown to be a valid method for an aeronautical-piston-engine preliminary project design optimization. In particular the procedure is able to analyze quite a wide range of design solutions, rejecting the ones that cannot fulfill the feasibility design specifications. This optimization algorithm could increase the aeronautical-piston-engine development, speeding up the production rate and joining modern computation performances and technological awareness to the long lasting traditional design experiences.

Studio di metodi di preparazione e caratterizzazione di nanostrutture per la funzionalizzazione di materiali ceramici

This thesis was carried out in the context of a co-tutoring program between Centro Ceramico Bologna (Italy) and Instituto di Tecnologia Ceramica, Castellón de la Plana (Spain). The subject of the thesis is the synthesis of silver nanoparticles and at their likely decorative application in the productive process of porcelain ceramic tiles. Silver nanoparticles were chosen as a case study, because metal nanoparticles are thermally stable, and they have non-linear optical properties when nano-structured, and therefore they develop saturated colours. The nanoparticles were synthesized by chemical reduction in aqueous solution, a method chosen because of its reduced working steps and energy costs. Besides such a synthesis method uses non-expensive and non-toxic raw material. By adopting this synthesis technique, it was also possible to control the dimension and the final shape of the nanoparticles. Several syntheses were carried out during the research work, modifying the molecular weight of the reducing agent and/or the firing temperature, in order to evaluate the influence such parameters have on the Ag-nanoparticles formation. The syntheses were monitored with the use of UV-Vis spectroscopy and the average dimension as well as the morphology of the nanoparticles was analysed by SEM. From the spectroscopic data obtained from each synthesis, a kinetic study was completed, relating the progress of the reaction to the two variables (ie temperature and molecular weight of the reducing agent). The aim was finding equations that allow the establishing of a relationship between the operating conditions during the synthesis and the characteristics of the final product. The next step was finding the best method of synthesis for the decorative application. For such a purpose the amount of nanoparticles, their average particle size, the shape and the agglomeration are considered. An aqueous suspension containing the nanoparticles is then sprayed over the fired ceramic tiles and they are subsequently thermally treated in conditions similar to the industrial one. The colorimetric parameters of the obtained ceramic tiles were studied and the method proved successful, giving the ceramic tiles stable and intense colours.

Studio dei metodi di valutazione della pericolosità associata ai "debris flow" in ambiente alpino

The present work concerns with the study of debris flows and, in particular, with the related hazard in the Alpine Environment. During the last years several methodologies have been developed to evaluate hazard associated to such a complex phenomenon, whose velocity, impacting force and inappropriate temporal prediction are responsible of the related high hazard level. This research focuses its attention on the depositional phase of debris flows through the application of a numerical model (DFlowz), and on hazard evaluation related to watersheds morphometric, morphological and geological characterization. The main aims are to test the validity of DFlowz simulations and assess sources of errors in order to understand how the empirical uncertainties influence the predictions; on the other side the research concerns with the possibility of performing hazard analysis starting from the identification of susceptible debris flow catchments and definition of their activity level. 25 well documented debris flow events have been back analyzed with the model DFlowz (Berti and Simoni, 2007): derived form the implementation of the empirical relations between event volume and planimetric and cross section inundated areas, the code allows to delineate areas affected by an event by taking into account information about volume, preferential flow path and digital elevation model (DEM) of fan area. The analysis uses an objective methodology for evaluating the accuracy of the prediction and involve the calibration of the model based on factors describing the uncertainty associated to the semi empirical relationships. The general assumptions on which the model is based have been verified although the predictive capabilities are influenced by the uncertainties of the empirical scaling relationships, which have to be necessarily taken into account and depend mostly on errors concerning deposited volume estimation. In addition, in order to test prediction capabilities of physical-based models, some events have been simulated through the use of RAMMS (RApid Mass MovementS). The model, which has been developed by the Swiss Federal Institute for Forest, Snow and Landscape Research (WSL) in Birmensdorf and the Swiss Federal Institute for Snow and Avalanche Research (SLF) takes into account a one-phase approach based on Voellmy rheology (Voellmy, 1955; Salm et al., 1990). The input file combines the total volume of the debris flow located in a release area with a mean depth. The model predicts the affected area, the maximum depth and the flow velocity in each cell of the input DTM. Relatively to hazard analysis related to watersheds characterization, the database collected by the Alto Adige Province represents an opportunity to examine debris-flow sediment dynamics at the regional scale and analyze lithologic controls. With the aim of advancing current understandings about debris flow, this study focuses on 82 events in order to characterize the topographic conditions associated with their initiation , transportation and deposition, seasonal patterns of occurrence and examine the role played by bedrock geology on sediment transfer.

La neoangiogenesi nel reimpianto autologo di tessuto ovarico in pazienti a rischio di fallimento ovarico precoce: ottimizzazione dei metodi di crioconservazione di corticle ovarica

Introduzione L’efficacia dei chemio/radioterapici ha aumentato notevolmente l’aspettativa di vita delle pazienti oncologiche, tuttavia, questi trattamenti possono compromettere la funzionalità ovarica. La crioconservazione di tessuto ovarico, con il successivo reimpianto, ha lo scopo di preservare la fertilità delle pazienti a rischio di fallimento ovarico precoce. Scopo dello studio Definire la migliore procedura di crioconservazione e reimpianto in grado di ottenere la neovascolarizzazione del tessuto reimpiantato nel minor tempo possibile al fine di diminuire la perdita follicolare causata dall’ischemia durante la procedura. Materiali e metodi Per ciascuna paziente (3) le biopsie ovariche, sono state prelevate laparoscopicamente e crioconservate secondo il protocollo di congelamento lento/scongelamento rapido. Campioni di corticale ovarica sono stati processati per l’analisi istologica, ultrastrutturale, immuistochimica e confocale per valutare la preservazione morfologiaca del tessuto. Le fettine di corticale ovarica sono state scongelate e reimpiantate ortotopicamente (2), nelle ovaia e in due tasche peritoneali, o eterotopicamente (1), in due tasche create nel sottocute sovrapubico. Risultati Le analisi di microscopia hanno mostrato il mantenimento di una discreta morfologia dello stroma, e dei vasi criopreservati e un lieve ma non significativo danneggiamento dei follicoli scongelati. Tutte le pazienti hanno mostrato la ripresa della funzionalità endocrina rispettivamente dopo 2/4 mesi dal reimpianto. Il color-doppler, inoltre ha rivelato un significativo aumento della vascolarizzazione ovarica rispetto alla quasi totale assenza di vascolarizzazione prima del reimpianto, quando le pazienti mostravano una conclamata menopausa. Conclusioni Lo studio ha confermato la ripresa della vascolarizzazione dell’ovaio in seguito a reimpianto avascolare di fettine di corticale, senza l’impiego di fattori esogeni o meccanici aggiuntivi, in tempi concordanti con i dati della letteratura. I risultati sono incoraggianti e l’avanzare degli studi e della ricerca potranno contribuire allo sviluppo di nuove metodologie di reimpianto che possano avere un successo clinico ed una sicurezza superiori a quelle finora ottenute.