Novel catalytic systems and methidologies for organocatalysis and photocatalysis

The thesis is divided into two main parts. In the first one organocatalysis is briefly introduced. Then, new enantiopure trityl pyrrolidines modified with an ionic tag are described. All the catalysts are tested in the benchmark Michael addition reaction to prove their activity and stereoselectivity. In the second part, photocatalysis is first introduced. Then, four different research projects are described. At first, the construction of a hybrid metal-organo-photoredox catalyst is described. The hybrid photocatalysts obtained were employed in the benchmark photoredox alkylation of aldehydes. Then, the use of visible light and a photocatalytic system for the cyclization of iodoaryl vinyl derivatives to tetrahydroquinoline structures is described. In addition, the reaction can also be performed using flow-chemistry. Finally, a mechanistic proposal based on some mechanistic studies is described. Third, a new photoredox catalyzed transformation for the synthesis of 2,3-dihydrofurans is reported. Depending on the involved starting materials, different pathways have arisen. A mechanistic proposal based on reported literatures and experimental data is described. At last, a new photoredox catalyzed transformation for the synthesis of 2-aminofurans is described. Electrophilic radical addition on allenamides and subsequential intramolecular cyclization are exploited. The reaction proceeds under very mild conditions and in 2-aminofurans are obtained in good to high yield. It represents one of the few applications of allenamides in photoredox catalysis. A mechanistic proposal is described. Finally, preliminary investigations on the applicability of the developed transformation under flow chemistry conditions.

Multi-phase electric drives for mobility

Multi-phase electrical drives are potential candidates for the employment in innovative electric vehicle powertrains, in response to the request for high efficiency and reliability of this type of application. In addition to the multi-phase technology, in the last decades also, multilevel technology has been developed. These two technologies are somewhat complementary since both allow increasing the power rating of the system without increasing the current and voltage ratings of the single power switches of the inverter. In this thesis, some different topics concerning the inverter, the motor and the fault diagnosis of an electric vehicle powertrain are addressed. In particular, the attention is focused on multi-phase and multilevel technologies and their potential advantages with respect to traditional technologies. First of all, the mathematical models of two multi-phase machines, a five-phase induction machine and an asymmetrical six-phase permanent magnet synchronous machines are developed using the Vector Space Decomposition approach. Then, a new modulation technique for multi-phase multilevel T-type inverters, which solves the voltage balancing problem of the DC-link capacitors, ensuring flexible management of the capacitor voltages, is developed. The technique is based on the proper selection of the zero-sequence component of the modulating signals. Subsequently, a diagnostic technique for detecting the state of health of the rotor magnets in a six-phase permanent magnet synchronous machine is established. The technique is based on analysing the electromotive force induced in the stator windings by the rotor magnets. Furthermore, an innovative algorithm able to extend the linear modulation region for five-phase inverters, taking advantage of the multiple degrees of freedom available in multi-phase systems is presented. Finally, the mathematical model of an eighteen-phase squirrel cage induction motor is defined. This activity aims to develop a motor drive able to change the number of poles of the machine during the machine operation.

Numerical and experimental analysis of 3D printed smart structures and systems

Three dimensional (3D) printers of continuous fiber reinforced composites, such as MarkTwo (MT) by Markforged, can be used to manufacture such structures. To date, research works devoted to the study and application of flexible elements and CMs realized with MT printer are only a few and very recent. A good numerical and/or analytical tool for the mechanical behavior analysis of the new composites is still missing. In addition, there is still a gap in obtaining the material properties used (e.g. elastic modulus) as it is usually unknown and sensitive to printing parameters used (e.g. infill density), making the numerical simulation inaccurate. Consequently, the aim of this thesis is to present several work developed. The first is a preliminary investigation on the tensile and flexural response of Straight Beam Flexures (SBF) realized with MT printer and featuring different interlayer fiber volume-fraction and orientation, as well as different laminate position within the sample. The second is to develop a numerical analysis within the Carrera' s Unified Formulation (CUF) framework, based on component-wise (CW) approach, including a novel preprocessing tool that has been developed to account all regions printed in an easy and time efficient way. Among its benefits, the CUF-CW approach enables building an accurate database for collecting first natural frequencies modes results, then predicting Young' s modulus based on an inverse problem formulation. To validate the tool, the numerical results are compared to the experimental natural frequencies evaluated using a digital image correlation method. Further, we take the CUF-CW model and use static condensation to analyze smart structures which can be decomposed into a large number of similar components. Third, the potentiality of MT in combination with topology optimization and compliant joints design (CJD) is investigated for the realization of automated machinery mechanisms subjected to inertial loads.

About stabilization of non-minimum phase systems by output feedback

This thesis work has been motivated by an internal benchmark dealing with the output regulation problem of a nonlinear non-minimum phase system in the case of full-state feedback. The system under consideration structurally suffers from finite escape time, and this condition makes the output regulation problem very hard even for very simple steady-state evolution or exosystem dynamics, such as a simple integrator. This situation leads to studying the approaches developed for controlling Non-minimum phase systems and how they affect feedback performances. Despite a lot of frequency domain results, only a few works have been proposed for describing the performance limitations in a state space system representation. In particular, in our opinion, the most relevant research thread exploits the so-called Inner-Outer Decomposition. Such decomposition allows splitting the Non-minimum phase system under consideration into a cascade of two subsystems: a minimum phase system (the outer) that contains all poles of the original system and an all-pass Non-minimum phase system (the inner) that contains all the unavoidable pathologies of the unstable zero dynamics. Such a cascade decomposition was inspiring to start working on functional observers for linear and nonlinear systems. In particular, the idea of a functional observer is to exploit only the measured signals from the system to asymptotically reconstruct a certain function of the system states, without necessarily reconstructing the whole state vector. The feature of asymptotically reconstructing a certain state functional plays an important role in the design of a feedback controller able to stabilize the Non-minimum phase system.

Multi-Principal Agency and the Compliance with Professional Guidelines in Health Systems: Economic and Regulatory Perspectives

Amid the trend of rising health expenditure in developed economies, changing the healthcare delivery models is an important point of action for service regulators to contain this trend. Such a change is mostly induced by either financial incentives or regulatory tools issued by the regulators and targeting service providers and patients. This creates a tripartite interaction between service regulators, professionals, and patients that manifests a multi-principal agent relationship, in which professionals are agents to two principals: regulators and patients. This thesis is concerned with such a multi-principal agent relationship in healthcare and attempts to investigate the determinants of the (non-)compliance to regulatory tools in light of this tripartite relationship. In addition, the thesis provides insights into the different institutional, economic, and regulatory settings, which govern the multi-principal agent relationship in healthcare in different countries. Furthermore, the thesis provides and empirically tests a conceptual framework of the possible determinants of (non-)compliance by physicians to regulatory tools issued by the regulator. The main findings of the thesis are first, in a multi-principal agent setting, the utilization of financial incentives to align the objectives of professionals and the regulator is important but not the only solution. This finding is based on the heterogeneity in the financial incentives provided to professionals in different health markets, which does not provide a one-size-fits-all model of financial incentives to influence clinical decisions. Second, soft law tools as clinical practice guidelines (CPGs) are important tools to mitigate the problems of the multi-principal agent setting in health markets as they reduce information asymmetries while preserving the autonomy of professionals. Third, CPGs are complex and heterogeneous and so are the determinants of (non-)compliance to them. Fourth, CPGs work but under conditions. Factors such as intra-professional competition between service providers or practitioners might lead to non-compliance to CPGs – if CPGs are likely to reduce the professional’s utility. Finally, different degrees of soft law mandate have different effects on providers’ compliance. Generally, the stronger the mandate, the stronger the compliance, however, even with a strong mandate, drivers such as intra-professional competition and co-management of patients by different professionals affected the (non-)compliance.

Low carbon systems for climate change mitigation and adaptation

Global warming and climate change have been among the most controversial topics after the industrial revolution. The main contributor to global warming is carbon dioxide (CO2), which increases the temperature by trapping heat in the atmosphere. Atmospheric CO2 concentration before the industrial era was around 280 ppm for a long period, while it has increased dramatically since the industrial revolution up to approximately 420 ppm. According to the Paris agreement it is needed to keep the temperature increase up to 2°C, preferably 1.5° C, to prevent reaching the tipping point of climate change. To keep the temperature increase below the range, it is required to find solutions to reduce CO2 emissions. The solutions can be low-carbon systems and transition from fossil fuels to renewable energy sources (RES). This thesis is allocated to the assessment of low-carbon systems and the reduction of CO2 by using RES instead of fossil fuels. One of the most important aspects to define the location and capacity of low-carbon systems is CO2 mass estimation. As mentioned, high-emission systems can be substituted by low-carbon systems. An example of high-emission systems is dredging. The global CO2 emission from dredging is relatively high which is associated with the growth of marine transport in addition to its high emission. Thus, ejectors system as alternative for dredging is investigated in chapter 2. For the transition from fossil fuels to RES, it is required to provide solutions for the RES storage problem. A solution could be zero-emission fuels such as hydrogen. However, the production of hydrogen requires electricity, and electricity production emits a large amount of CO2. Therefore, the last three chapters are allocated to hydrogen generation via electrolysis, at the current condition and scenarios of RES and variation of cell characteristics and stack materials, and its delivery.

Hardware-software design of embedded systems for intelligent sensing applications

This Thesis wants to highlight the importance of ad-hoc designed and developed embedded systems in the implementation of intelligent sensor networks. As evidence four areas of application are presented: Precision Agriculture, Bioengineering, Automotive and Structural Health Monitoring. For each field is reported one, or more, smart device design and developing, in addition to on-board elaborations, experimental validation and in field tests. In particular, it is presented the design and development of a fruit meter. In the bioengineering field, three different projects are reported, detailing the architectures implemented and the validation tests conducted. Two prototype realizations of an inner temperature measurement system in electric motors for an automotive application are then discussed. Lastly, the HW/SW design of a Smart Sensor Network is analyzed: the network features on-board data management and processing, integration in an IoT toolchain, Wireless Sensor Network developments and an AI framework for vibration-based structural assessment.