Design and Manufacturing of a Nd-Doped Phosphate Glass-Based Jewel

This paper reports the results of the designing, manufacturing and characterization of a jewel obtained by means of coupling the dogmas of industrial design to the analytical engineering approach. The key role in the design of the jewel was played by an in-house synthesized Neodymium (Nd)-doped phosphate glass, selected due to its easy handling and capability to change color according to the incident light wavelength. The glass core was covered by a metal alloy to mitigate its relatively high fragility and sensitivity to thermal shock and, at the same time, to highlight and preserve its beauty. The selection of the proper metal alloy, having thermo-mechanical properties compatible with those exhibited by the glass, was carried out by means of Ashby’s maps, a powerful tool commonly adopted in the field of industrial design

FITTING A PARAMETRIC MODEL TO A CLOUD OF POINTS VIA OPTIMIZATION METHODS

Computer Aided Design (CAD) is a powerful tool for designing parametric geometry. However, many CAD models of current configurations are constructed in previous generations of CAD systems, which represent the configuration simply as a collection of surfaces instead of as a parametrized solid model. But since many modern analysis techniques take advantage of a parametrization, one often has to re-engineer the configuration into a parametric model. The objective here is to generate an efficient, robust, and accurate method for fitting parametric models to a cloud of points. The process uses a gradient-based optimization technique, which is applied to the whole cloud, without the need to segment or classify the points in the cloud a priori. First, for the points associated with any component, a variant of the Levenberg-Marquardt gradient-based optimization method (ILM) is used to find the set of model parameters that minimizes the least-square errors between the model and the points. The efficiency of the ILM algorithm is greatly improved through the use of analytic geometric sensitivities and sparse matrix techniques. Second, for cases in which one does not know a priori the correspondences between points in the cloud and the geometry model\u27s components, an efficient initialization and classification algorithm is introduced. While this technique works well once the configuration is close enough, it occasionally fails when the initial parametrized configuration is too far from the cloud of points. To circumvent this problem, the objective function is modified, which has yielded good results for all cases tested. This technique is applied to a series of increasingly complex configurations. The final configuration represents a full transport aircraft configuration, with a wing, fuselage, empennage, and engines. Although only applied to aerospace applications, the technique is general enough to be applicable in any domain for which basic parametrized models are available

3d food printing: study and applications to produce innovative food products.

La stampa 3D degli alimenti rappresenta una tecnologia innovativa ed emergente capace di costruire un oggetto tridimensionale partendo da un modello CAD creato su software di disegno grafico. Durante gli ultimi anni molti studi hanno dimostrato come questa tecnologia sia stata applicata per la produzione di alimenti nuovi. L’obiettivo principale di questa tesi è stato l’approfondimento e il miglioramento della tecnologia di stampa 3D nel settore alimentare contribuendo alla creazione di alimenti dalle proprietà mai esplorate prima. Dopo un’analisi dell’evoluzione temporale della tecnologia di stampa 3D nel settore alimentare, una varietà di altri aspetti sono stati studiati, tra cui la capacità di creare e modificare alimenti dalle nuove texture attraverso la progettazione di nuovi design, inoltre è stata oggetto di studio la stampa 3D ad alta velocità, tema interessante dal punto di vista dell’applicazione in campo industriale. Gli studi si sono focalizzati sull’utilizzo di due diverse matrici di stampa: impasto a base di cereali e gel a base d’amido, stampando strutture geometriche (cubi, parallelepipedi) e design ispirati alla natura (tessuti interni delle mele). La tesi è strutturata in 8 capitoli: una breve introduzione (capitolo 1), obiettivi e linee di ricerca (capitolo 2) e altri cinque capitoli corrispondenti alle 5 pubblicazioni su riviste internazionali; Drawing the scientific landscape of 3D Food Printing. Maps and interpretation of the global information in the first 13 years of detailed experiments, from 2007 to 2020’(capitolo 3) and ‘Rheological properties, dispensing force and printing fidelity of starchy-gels modulated by concentration, temperature and resting time’ (capitolo 4). I capitoli 5 e 6 sono dedicati alla creazione di alimenti stampati in 3D con proprietà meccaniche desiderate e personalizzabili: Programmable texture properties of cereal-based snack mediated by 3D printing technology’ (capitolo 5), ‘Extending 3D food printing application. Apple tissues microstructure as CAD model to create innovative cereal-based snacks’ (capitolo 6). Il capitolo 7 si è focalizzato sulla stampa 3D ad alta velocità: ‘Extending the 3D food printing tests at high speed. Material deposition and effect of non-printing movements on the final quality of printed structures’. E infine il capitolo 8 racchiude le conclusioni e alter discussioni generali riguardanti la tesi.3D printing (3DP) represents an innovative and emerging technology aiming to build three-dimensional objects starting from the computer-aided model. During last years main studies showed the application of this technology to produce innovative foods. The main aim of this research was the better understanding and the implementation of 3D Printing in the food sector aiming to contribute to the creation of food with unprecedented properties. After an analysis on the temporal evolution of 3D Food Printing (3DFP) in scientific field, a variety of relevant aspects have been studied: the capability of modifying the texture properties of the end products by means of accurate design of the digital models and the printing at high speed that could open for a more practical application at industrial level. Moreover, the studies have focused on two different matrix: cereals based and starchy gels, printing geometric structures (cube, parallelepiped) and design inspired by nature (apple tissue). The thesis is structured in 8 chapters: a brief introduction (chapter 1), objects and outlines of research (chapter 2) and the other sections consists of five published papers in international peer reviewed journals ‘Drawing the scientific landscape of 3D Food Printing. Maps and interpretation of the global information in the first 13 years of detailed experiments, from 2007 to 2020’(chapter 3); ‘Rheological properties, dispensing force and printing fidelity of starchy-gels modulated by concentration, temperature and resting time’ (chapter 4). The chapters 5 and 6 has been dedicated to the creation of 3D-printed food with desired and programmable mechanical properties: ‘Programmable texture properties of cereal-based snack mediated by 3D printing technology’ (chapter 5), ‘Extending 3D food printing application. Apple tissues microstructure as CAD model to create innovative cereal-based snacks’ (chapter 6). Chapter 7 focused on speed up of 3DFP: ‘Extending the 3D food printing tests at high speed. Material deposition and effect of non-printing movements on the final quality of printed structures’. Finally chapter 8 contains the conclusions and some general discussion of the thesis