Studio e sviluppo di un motore a 2 tempi diesel veloce di nuova concezione per applicazioni automobilistiche

The Department of Mechanical and Civil Engineering (DIMeC) of the University of Modena and Reggio Emilia is developing a new type of small capacity HSDI 2-Stroke Diesel engine (called HSD2), featuring a specifically designed combustion system, aimed to reduce weight, size and manufacturing costs, and improving pollutant emissions at partial load. The present work is focused on the analysis of the combustion and the scavenging process, investigated by means of a version of the KIVA-3V code customized by the University of Chalmers and modified by DIMeC. The customization of the KIVA-3V code includes a detailed combustion chemistry approach, coupled with a comprehensive oxidation mechanism for diesel oil surrogate and the modeling of turbulence/chemistry interaction through the PaSR (Partially Stirred Reactor) model. A four stroke automobile Diesel engine featuring a very close bore size is taken as a reference, for both the numerical models calibration and for a comparison with the 2-Stroke engine. Analysis is carried out trough a comparison between HSD2 and FIAT 1300 MultiJet in several operating conditions, at full and partial load. Such a comparison clearly demonstrates the effectiveness of the two stroke concept in terms of emissions reduction and high power density. However, HSD2 is still a virtual engine, and experimental results are needed to assume the reliability of numerical results.

Studio di fattibilità di un impianto di servizio cogenerativo per un'industria farmaceutica

Il seguente elaborato analizza lo studio di fattibilità di un impianto di servizio cogenerativo per un’industria farmaceutica. Il sito industriale preso in esame ben si presta all’istallazione di un cogeneratore, vista la contemporanea richiesta di energia elettrica e termica. Grazie all’analisi dei dati di partenza relativi all’impianto industriale, verrà scelta la tipologia e la taglia ottimale del gruppo, nonché la sua migliore ubicazione. Attraverso una profonda analisi economica verrà mostrata la redditività del progetto.

Food safety in wine: optimization of analytical controls and evaluation of production technologies

This PhD thesis has been proposed to validate and then apply innovative analytical methodologies for the determination of compounds with harmful impact on human health, such as biogenic amines and ochratoxin A in wines. Therefore, the influence of production technology (pH, amino acids precursor and use of different malolactic starters) on biogenic amines content in wines was evaluated. An HPLC method for simultaneous determination of amino acids and amines with precolumnderivatization with 9-Fluorenyl-methoxycarbonyl chloride (FMOC-Cl) and UV detection was developed. Initially, the influence of pH, time of derivatization, gradient profile were studied. In order to improve the separation of amino acids and amines and reduce the time of analysis, it was decided to study the influence of different flows and the use of different columns in the chromatographic method. Firstly, a C18 Luna column was used and later two monolithic columns Chromolith in series. It appeared to be suitable for an easy, precise and accurate determination of a relatively large number of amino acids and amines in wines. This method was then applied on different wines produced in the Emilia Romagna region. The investigation permitted to discriminate between red and white wines. Amino acids content is related to the winemaking process. Biogenic amines content in these wines does not represent a possible toxicological problem for human health. The results of the study of influence of technologies and wine composition demonstrated that pH of wines and amino acids content are the most important factors. Particularly wines with pH > 3,5 show higher concentration of biogenic amines than wines with lower pH. The enrichment of wines by nutrients also influences the content of some biogenic amines that are higher in wines added with amino acids precursors. In this study, amino acids and biogenic amines are not statistically affected by strain of lactic acid bacteria inoculated as a starter for malolactic fermentation. An evaluation of different clean-up (SPE-MycoSep; IACs and LLE) and determination methods (HPLC and ELISA) of ochratoxin A was carried out. The results obtained proved that the SPE clean-up are reliable at the same level while the LLE procedures shows lowest recovery. The ELISA method gave a lower determination and a low reproducibility than HPLC method.

Application of different instrumental techniques to the selective evaluation of bio-sensible compounds in foodstuff of animal and vegetable origin

This PhD thesis describes the application of some instrumental analytical techniques suitable to the study of fundamental food products for the human diet, such as: extra virgin olive oil and dairy products. These products, widely spread in the market and with high nutritional values, are increasingly recognized healthy properties although their lipid fraction might contain some unfavorable components to the human health. The research activity has been structured in the following investigations: “Comparison of different techniques for trans fatty acids analysis” “Fatty acids analysis of outcrop milk cream samples, with particular emphasis on the content of Conjugated Linoleic Acid (CLA) and trans Fatty Acids (TFA), by using 100m high-polarity capillary column” “Evaluation of the oxidited fatty acids (OFA) content during the Parmigiano-Reggiano cheese seasoning” “Direct analysis of 4-desmethyl sterols and two dihydroxy triterpenes in saponified vegetal oils (olive oil and others) using liquid chromatography-mass spectrometry” “Quantitation of long chain poly-unsatured fatty acids (LC-PUFA) in base infant formulas by Gas Chromatography, and evaluation of the blending phases accuracy during their preparation” “Fatty acids composition of Parmigiano Reggiano cheese samples, with emphasis on trans isomers (TFA)”

Low-dimensional carbon allotropes: an electron microscopy investigation

The research reported in this manuscript concerns the structural characterization of graphene membranes and single-walled carbon nanotubes (SWCNTs). The experimental investigation was performed using a wide range of transmission electron microscopy (TEM) techniques, from conventional imaging and diffraction, to advanced interferometric methods, like electron holography and Geometric Phase Analysis (GPA), using a low-voltage optical set-up, to reduce radiation damage in the samples. Electron holography was used to successfully measure the mean electrostatic potential of an isolated SWCNT and that of a mono-atomically thin graphene crystal. The high accuracy achieved in the phase determination, made it possible to measure, for the first time, the valence-charge redistribution induced by the lattice curvature in an individual SWCNT. A novel methodology for the 3D reconstruction of the waviness of a 2D crystal membrane has been developed. Unlike other available TEM reconstruction techniques, like tomography, this new one requires processing of just a single HREM micrograph. The modulations of the inter-planar distances in the HREM image are measured using Geometric Phase Analysis, and used to recover the waviness of the crystal. The method was applied to the case of a folded FGC, and a height variation of 0.8 nm of the surface was successfully determined with nanometric lateral resolution. The adhesion of SWCNTs to the surface of graphene was studied, mixing shortened SWCNTs of different chiralities and FGC membranes. The spontaneous atomic match of the two lattices was directly imaged using HREM, and we found that graphene membranes act as tangential nano-sieves, preferentially grafting achiral tubes to their surface.

Morphogenesis of follicular epithelium in Drosophila melanogaster: function of von Hippel-Lindau tumour suppressor gene

During my PhD I have been involved in several projects regarding the morphogenesis of the follicular epithelium, such as the analysis of the pathways that correlate follicular epithelium patterning and eggshell genes expression. Moreover, I used the follicular epithelium as a model system to analyze the function of the Drosophila homolog of the human von Hippel-Lindau (d-VHL) during oogenesis, in order to gain insight into the role of h-VHL for the pathogenesis of VHL disease. h-VHL is implicated in a variety of processes and there is now a greater appreciation of HIF-independent h-VHL functions that are relevant to tumour development, including maintenance and organization of the primary cilium, maintenance of the differentiated phenotype in renal cells and regulation of epithelial-mesenchymal transition. However, the function of h-VHL gene during development has not been fully understood. It was previously shown that d-VHL down-regulates the motility of tubular epithelial cells (tracheal cells) during embryogenesis. Epithelial morphogenesis is important for organogenesis and pivotal for carcinogenesis, but mechanisms that control it are poorly understood. The Drosophila follicular epithelium is a genetically tractable model to understand these mechanisms in vivo. Therefore, to examine whether d-VHL has a role in epithelial morphogenesis and maintenance, I performed genetic and molecular analyses by using in vivo and in vitro approaches. From my analysis, I determined that d-VHL binds to and stabilizes microtubules. Loss of d-VHL depolymerizes the microtubule network during oogenesis, leading to a possible deregulation in the subcellular trafficking transport of polarity markers from Golgi apparatus to the different domains in which follicle cells are divided. The analysis carried out has allowed to establish a significant role of d-VHL in the maintenance of the follicular epithelium integrity.