Set up of a procedure for correlation analysis between current discharge and dose delivery in a pulsed power plasma device for medical application

This thesis work aims to find a procedure for isolating specific features of the current signal from a plasma focus for medical applications. The structure of the current signal inside a plasma focus is exclusive of this class of machines and a specific analysis procedure has to be developed. The hope is to find one or more features that shows a correlation with the dose erogated. The study of the correlation between the current discharge signal and the dose delivered by a plasma focus could be of some importance not only for the practical application of dose prediction but also for expanding the knowledge anbout the plasma focus physics. Vatious classes of time-frequency analysis tecniques are implemented in order to solve the problem.

Experimental set up and characterization of a prototype for breast microwave imaging

Nella presente tesi è stato sviluppato un sistema di acquisizione automatico finalizzato allo studio del breast microwave imaging. Le misure sono state eseguite in configurazione monostatica, in cui viene acquisito un segnale da diverse posizioni lungo il perimetro dell’area di indagine. A questo scopo, è stato installato un motore ad alta precisione che permette la rotazione del fantoccio e l’esecuzione automatica delle misure da un numero di posizioni fissato. Per automatizzare il processo di acquisizione, è stato inoltre sviluppato appositamente un software in ambiente LabView. Successivamente, è stata eseguita una intensa sessione di misure finalizzate alla caratterizzazione del sistema sviluppato al variare delle condizioni di misura. Abbiamo quindi utilizzato dei fantocci di tumore di diverse dimensioni e permittività elettrica per studiare la sensibilità della strumentazione in condizione di mezzo omogeneo. Dall’analisi delle ricostruzioni multifrequenza effettuate tramite diversi algoritmi di tipo TR-MUSIC sul range di frequenze selezionato, abbiamo notato che il tumore è ricostruito correttamente in tutti gli scenari testati. Inoltre, abbiamo creato un ulteriore fantoccio per simulare la presenza di una disomogeneità nel dominio di imaging. In questo caso, abbiamo studiato le performances del sistema di acquisizione al variare della posizione del tumore, le cui caratteristiche sono state fissate, e della permittività associata al fantoccio. Dall’analisi dei risultati appare che le performances di ricostruzione sono condizionate dalla presenza della disomogeneità, in modo particolare se il tumore è posizionato all’interno di essa. Infine, abbiamo studiato delle performance di due algoritmi di ricostruzione 3D: uno di essi è basato sulla sovrappo- sizione tomografica e sfrutta metodi di interpolazione, l’altro si basa sull’utilizzo di un propagatore 3D per il dipolo Hertziano in approssimazione scalare.

Feasibility study and flow scheduling optimization of a multi-product pipeline system

The first goal of this study is to analyse a real-world multiproduct onshore pipeline system in order to verify its hydraulic configuration and operational feasibility by constructing a simulation model step by step from its elementary building blocks that permits to copy the operation of the real system as precisely as possible. The second goal is to develop this simulation model into a user-friendly tool that one could use to find an “optimal” or “best” product batch schedule for a one year time period. Such a batch schedule could change dynamically as perturbations occur during operation that influence the behaviour of the entire system. The result of the simulation, the ‘best’ batch schedule is the one that minimizes the operational costs in the system. The costs involved in the simulation are inventory costs, interface costs, pumping costs, and penalty costs assigned to any unforeseen situations. The key factor to determine the performance of the simulation model is the way time is represented. In our model an event based discrete time representation is selected as most appropriate for our purposes. This means that the time horizon is divided into intervals of unequal lengths based on events that change the state of the system. These events are the arrival/departure of the tanker ships, the openings and closures of loading/unloading valves of storage tanks at both terminals, and the arrivals/departures of trains/trucks at the Delivery Terminal. In the feasibility study we analyse the system’s operational performance with different Head Terminal storage capacity configurations. For these alternative configurations we evaluated the effect of different tanker ship delay magnitudes on the number of critical events and product interfaces generated, on the duration of pipeline stoppages, the satisfaction of the product demand and on the operative costs. Based on the results and the bottlenecks identified, we propose modifications in the original setup.

Set-up di banchi prova per l'analisi strutturale della parte ciclistica di un motoveicolo da competizione

Il lavoro della tesi si compone di due parti principali: 1) progettazione del banco prova statico e set up dei banchi prova per la caratterizzazione a rigidezza. 2) Analisi dei risultati di spostamento e deformazione. Il fine ultimo del lavoro di tesi è stato quello di validare la moto progettata all'interno del Team UBM Motostudent di cui faccio parte, ed ottenere spunti per la riprogettazione degli elementi in fibra di carbonio. Inoltre i banchi progettati sono stati riutilizzati per testare i nuovi elementi, da telaio e telaietto riprogettati al nuovo forcellone.

Study of a pulsed LED set-up to characterise the light response of SiPM sensors for the EIC dRICH detector

L’Electron Ion Collider (EIC) è un futuro acceleratore di particelle che ha l’obiettivo di approfondire le nostre conoscenze riguardo l’interazione forte, una delle quattro interazioni fondamentali della natura, attraverso collisioni di elettroni su nuclei e protoni. L’infrastruttura del futuro detector comprende un sistema d’identificazione basato sull’emissione di luce Cherenkov, un fenomeno che permette di risalire alla massa delle particelle. Una delle configurazioni prese in considerazione per questo sistema è il dual-radiator RICH, basato sulla presenza di due radiatori all’esterno dei quali si trovano dei fotorivelatori. Un’opzione per questi sensori sono i fotorivelatori al silicio SiPM, oggetto di questo lavoro di tesi. L’obiettivo dell’attività è lo studio di un set-up per la caratterizzazione della risposta di sensori SiPM a basse temperature, illuminati attraverso un LED. Dopo un’analisi preliminare per determinare le condizioni di lavoro, si è trovato che la misura è stabile entro un errore del 3.5%.

Development and scale-up studies of bio-based poly(ester-amide)s

Plastics are polymers of conventional and extensive use in our day-to-day life. This is due to their light weight, adaptability to different uses and low prices. A downside of such extensive use is the environmental pollution arising from plastic production and disposal. Indeed, many commodity polymers are produced from non-renewable resources while other do not bio-degrade after their end-of-life disposal. Consequently, the ideal polymer comes from renewable raw materials and bio-degrades after its disposal, meaning that it would do little or no harm to the environment from the beginning to the end of its life cycle. In this thesis project a class of bio-based and bio-degradable co-polymers, namely poly(ester-amide)s, was investigated because of their tunable mechanical and bio-degradation properties as well as their renewable origin. Such polymers were synthetized and characterized thermically and mechanically. Furthermore, a scale-up procedure was developed and applied to one polymer and processing trials were made with the material obtained after scale-up.

Design and management of a supply chain: a joint location-inventory problem under uncertainty (Part B)

In recent years, global supply chains have increasingly suffered from reliability issues due to various external and difficult to-manage events. The following paper aims to build an integrated approach for the design of a Supply Chain under the risk of disruption and demand fluctuation. The study is divided in two parts: a mathematical optimization model, to identify the optimal design and assignments customer-facility, and a discrete-events simulation of the resulting network. The first one describes a model in which plant location decisions are influenced by variables such as distance to customers, investments needed to open plants and centralization phenomena that help contain the risk of demand variability (Risk Pooling). The entire model has been built with a proactive approach to manage the risk of disruptions assigning to each customer two types of open facilities: one that will serve it under normal conditions and a back-up facility, which comes into operation when the main facility has failed. The study is conducted on a relatively small number of instances due to the computational complexity, a matheuristic approach can be found in part A of the paper to evaluate the problem with a larger set of players. Once the network is built, a discrete events Supply Chain simulation (SCS) has been implemented to analyze the stock flow within the facilities warehouses, the actual impact of disruptions and the role of the back-up facilities which suffer a great stress on their inventory due to a large increase in demand caused by the disruptions. Therefore, simulation follows a reactive approach, in which customers are redistributed among facilities according to the interruptions that may occur in the system and to the assignments deriving from the design model. Lastly, the most important results of the study will be reported, analyzing the role of lead time in a reactive approach for the occurrence of disruptions and comparing the two models in terms of costs.

SmartForge: An event-driven architecture for simulator-based process optimization

In the metal industry, and more specifically in the forging one, scrap material is a crucial issue and reducing it would be an important goal to reach. Not only would this help the companies to be more environmentally friendly and more sustainable, but it also would reduce the use of energy and lower costs. At the same time, the techniques for Industry 4.0 and the advancements in Artificial Intelligence (AI), especially in the field of Deep Reinforcement Learning (DRL), may have an important role in helping to achieve this objective. This document presents the thesis work, a contribution to the SmartForge project, that was performed during a semester abroad at Karlstad University (Sweden). This project aims at solving the aforementioned problem with a business case of the company Bharat Forge Kilsta, located in Karlskoga (Sweden). The thesis work includes the design and later development of an event-driven architecture with microservices, to support the processing of data coming from sensors set up in the company's industrial plant, and eventually the implementation of an algorithm with DRL techniques to control the electrical power to use in it.

Life cycle assessment (LCA) of a bio-fuel cell fed with waste biomass: potential for scale-up and process optimization

In this Thesis, a life cycle analysis (LCA) of a biofuel cell designed by a team from the University of Bologna was done. The purpose of this study is to investigate the possible environmental impacts of the production and use of the cell and a possible optimization for an industrial scale-up. To do so, a first part of the paper was devoted to studying the present literature on biomass, and fuel cell treatments and then LCA studies on them. The experimental part presents the work done to create the Life Cycle Inventory and Life Cycle Impact Assessment. Several alternative scenarios were created to study process optimization. Reagents and energy supply were changed. To examine whether this technology can be competitive, a comparison was made with some biofuel cell use scenarios with traditional biomass treatment technologies. The result of this study is that this technology is promising from an environmental point of view in case it is possible to recover nutrients in output, without excessive energy consumption, and to minimize the use of energy used to prepare the solution.