2 resultados para Mixed work

em AMS Tesi di Laurea - Alm@DL - Università di Bologna


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Due to the high price of natural oil and harmful effects of its usage, as the increase in emission of greenhouse gases, the industry focused in searching of sustainable types of the raw materials for production of chemicals. Ethanol, produced by fermentation of sugars, is one of the more interesting renewable materials for chemical manufacturing. There are numerous applications for the conversion of ethanol into commodity chemicals. In particular, the production of 1,3-butadiene whose primary source is ethanol using multifunctional catalysts is attractive. With the 25% of world rubber manufacturers utilizing 1,3-butadiene, there is an exigent need for its sustainable production. In this research, the conversion of ethanol in one-step process to 1,3-butadiene was studied. According to the literature, the mechanisms which were proposed to explain the way ethanol transforms into butadiene require to have both acid and basic sites. But still, there are a lot of debate on this topic. Thus, the aim of this research work is a better understanding of the reaction pathways with all the possible intermediates and products which lead to the formation of butadiene from ethanol. The particular interests represent the catalysts, based on different ratio Mg/Si in comparison to bare magnesia and silica oxides, in order to identify a good combination of acid/basic sites for the adsorption and conversion of ethanol. Usage of spectroscopictechniques are important to extract information that could be helpful for understanding the processes on the molecular level. The diffuse reflectance infrared spectroscopy coupled to mass spectrometry (DRIFT-MS) was used to study the surface composition of the catalysts during the adsorption of ethanol and its transformation during the temperature program. Whereas, mass spectrometry was used to monitor the desorbed products. The set of studied materials include MgO, Mg/Si=0.1, Mg/Si=2, Mg/Si=3, Mg/Si=9 and SiO2 which were also characterized by means of surface area measurements.

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Nella presente tesi, dopo una prima parte dedicata all'analisi del concetto di realtà mediata e delle sue varie specializzazioni, verranno illustrati i principali dispositivi hardware presenti attualmente sul mercato, analizzandone le caratteristiche, gli aspetti innovativi e la diffusione raggiunta al momento. Si passerà quindi ad esaminare nel dettaglio il visore Microsoft HoloLens, impiegato per la realizzazione del progetto di laurea, per arrivare alla descrizione dello sviluppo di un'applicazione. Il software realizzato rappresenta un esempio di applicazione della realtà mista al campo del design di interni: verranno esaminati strumenti di sviluppo, architettura, casi d'uso e work-flow dell'applicazione. Infine verranno descritte le fasi di test, i costi di sviluppo dell'applicazione e il feedback ricevuto dagli utenti.