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Oxide-dispersion-strengthened (ODS) steel is a material that is being studied for its potential in high-temperature and high-irradiation applications, such as nuclear fusion reactors or IV generation fission reactors. Its properties derive from the presence of nano-dispersed oxide particles that act as a barrier against the movement of dislocations, hence reducing susceptibility to creep, and as sinks for irradiation-induced defects, thus reducing the stress in the metal matrix itself. In this study, a powder for additive manufacturing is produced with mechanical alloying (MA) in a planetary ball mill; seven sets of powders are produced in this study, each with a different set of milling parameters, so that the best-suited specimen for the chosen manufacturing process may be selected. The powder is studied with a Scanning Electron Microscope (SEM) imaging and optical microscopy in order to characterize the formation of the oxides with an acceptable level of detail and to determine the size distribution of the powder particles. The results show the choice of acetic acid and ethanol as process control agents for dry grinding of the powders does not improve the characteristics of the end product to a significant extent. An increase in the grinding time seems more effective in increasing the yield and reducing the average size of the particles to an acceptable range, but it may result in a compromise in terms of the powder’s flowability.

In this master thesis, the characteristics of reduced-activation ferritic Fe-9Cr oxide-dispersion-strengthened (ODS) steel, produced via mechanical alloying and laser-based additive manufacturing, are explored, with the main focus on the microstructure and the presence and size of the Y-based nano-oxides. Reference steel samples are also produced with the same processes, in order to characterize the impact of Yttria on the characteristics of the final steel. The study employs metallographic techniques, SEM, TEM, STEM and synchrotron x-ray diffraction to assess the steel properties. The results show the typical structure and microstructure of metal additive manufacturing. Melt pools and layers are clearly visible. The layer size is on average roughly consistent with the set fabrication parameter, while the melt pools’ size appear to increase with higher energy density. Two types of grains can be identified: elongated columnar grains spanning from the edge towards the centre of the melt pool, and equiaxed grains, mostly localized in the centre. Regions that are expected to have experienced lower thermal gradients during solidification seem to develop larger grains on average. Instances of abnormal grain structure are also highlighted, such as the presence of hourglass-shaped grains. Overall, the samples are clearly fine-grained, with the largest grains still below 2 µm on average. In some of the samples, a higher degree of porosity than what is expected for this consolidation technique is noticed. Possible explanations are given, such as the large spread in characteristics of the feed powder, possible material stripping during cutting and grinding and volume contraction during the melt pool formation. Nanoparticles are clearly visible throughout all of the ODS steel samples. They appear larger than expected for high grade ODS, with a large presence of dispersoids above 40 nm in diameter. Their morphology appears to be spherical in most cases and octahedral crystalline in some. There is some evidence supporting the formation of a core-shell structure and heterogeneous composition inside the particles themselves. Possible traces of V presence are also found in some ODS particles. Some dispersoids below 10 nm are also identifiable, but their chemical nature cannot be confirmed due to the limited resolution of EDXS in this study.

A tele-monitoring system, based on a soft transducer network, developed by students of the Course "Measurements on Communications Network" (MRC), at the Department of Electrical Engineering and Information Technology, University of Naples Federico II, is presented. This project is the result of an innovative education approach for (i) overcoming specialization of single Courses on different aspects of advanced tele-monitoring and (ii) experimenting integrated design approach in a realistic environment. Therefore, the Course emulates the creation of a start up, MRC 2017 Ltd, where the students act like junior designers supervised by the teachers as Project Leaders and senior consultants. MRC 2017 Ltd receives an order from an actual customer, Del Bo Consortium, and leverages the project developments by actual industrial partners, STMicroelectronics for embedded solutions, and Nexus-tlc for software platform of Internet of Things.

Leber's hereditary optic neuropathy (LHON), a disease associated with a mitochondrial DNA mutation, is characterized by blindness due to degeneration of retinal ganglion cells (RGCs) and their axons, which form the optic nerve. We show that a sustained pathological autophagy and compartment-specific mitophagy activity affects LHON patient-derived cells and cybrids, as well as induced pluripotent-stem-cell-derived neurons. This is variably counterbalanced by compensatory mitobiogenesis. The aberrant quality control disrupts mitochondrial homeostasis as reflected by defective bioenergetics and excessive reactive oxygen species production, a stress phenotype that ultimately challenges cell viability by increasing the rate of apoptosis. We counteract this pathological mechanism by using autophagy regulators (clozapine and chloroquine) and redox modulators (idebenone), as well as genetically activating mitochondrial biogenesis (PGC1-α overexpression). This study substantially advances our understanding of LHON pathophysiology, providing an integrated paradigm for pathogenesis of mitochondrial diseases and druggable targets for therapy.