Mechanical and Industrial Engineering PhD @ROMA TRE

Mechanical micro-probing as a versatile technique for the surface engineering: from mapping to patterning (Ph.D. Thesis)

In the last decades, nanoscience and nanotechnology raised their role and impact in industry due to the increasing importance of the analysis and characterization of materials at the nano-scale. In fact, at a such small (10-9 m) scale, materials exhibit properties (such as strength, stiffness, hardness but also electrical resistivity and conductivity or optical absorption) that are significantly different from the properties of the same matter at bulk scale. For this reason, it has been necessary to realize and develop...

5-Level 3-Phase Back To Back E-Type Power Converter Topology: design, modulation and control

The use of variable speed drive plays an important role in commercial, industrial and military applications, where small size and lightweight, low maintenance, reliability in a wide range of environments and good efficiency are required. For these applications, the complete drive system can be basically composed of three main parts: high-speed generators, double conversion AC/DC-DC/AC ((Back To Back)) and load. Starting from a variable three-phase input AC voltage provided by grid or the permanent-magnet synchronous generator (PMSG) at high fundamental...

“Litografia tramite nanoindentazione per patterning superficiale : effetti locali sull’energia libera superficiale e meccanismi di adesione”

La tematica in oggetto può essere suddivisa in tre fasi di ricerca: 1)        Studio dell’energia libera superficiale di materiali selezionati in funzione dei parametri del patterning superficiale; 2)        Misure locali di energia libera superficiale su micro particelle per applicazioni biomediche; 3)        Effetti di adesione in micro e nano dispositivi (M.E.M.S.). La nano-fabbricazione interessa qualsiasi processo che produce pattern di strutture con dimensioni minori di 100 nanometri in almeno una dimensione. L’electron-beam litography (EBL) e l’incisione tramite Focused ion beam (FIB)...

3D FIB nanolithography using nanomachining technics

  The Focused Ion Beam (FIB)microscopes are extermely versatile and powerful instruments for materials research. It’s a tool to realize sample imaging, sectioning,  ion-lithography and nano/micro machining on surfaces. The art to produce complex shapes at the nanoscales is often limited with the default pattern engine included in the instrument software or you need to buy a very expensive add-in for enlarging the potentiality of your pattern strategy. An alternative way to improve the complexity of your pattern is the ‘stream file’....

Study of combustion development and modeling of the pollutants formation process in diesel engines

In recent years, to improve the efficiency of diesel engines and, at same time, to reduce the pollutants emission (NOx and soot), the researchers and the automotive producers have focused on technologies that enable compliance with both requirements: devices for the exhaust after-treatment, exhaust gas recirculation (EGR) and new combustion models. Thus, it was necessary a deeper understanding of the combustion process in diesel engines with direct injection. The research is related to the analysis of spray formation, combustion and...

Non-intrusive measurements on Engines – Acoustic radiations

The main advantage to develop non-intrusive measurement procedures rely on the possibility to perfom testing on engines without benching preparations, i.e outside labs. Since this route naturally leads not only on monitoring purposes but also on control duties, it is interesting to look for simple sensing chains which can be utilized on mass productions and can easily integrate with Engine Control Units. Real Time monitoring and control of combustion  process in engines is the way to deal with tight pollutant regulations. On a...

Jet aero-acoustics

  The development of aircraft transportation has brought an increase of air traffic volume and issues related to environmental aspects such as carbon and NOx emissions and noise pollution. The jet exhausting from aircraft engine is the responsible for pollutant discharge and one of the main sources of community and interior noise. Jet noise is a challenging topic for the scientific community. Despite of many years of research, the mechanism by which turbulent structures generate noise is still unknown. The...

Safety and health in quarry and mining activities

the physical phenomenon of vibration in context of safety and health on work is classified as a physical agent that can be a danger source for the environment and can generate hazards for the human health, if the exposure overtakes a threshold defined (limit dose exposure). The work is focused on the effects of exposure to whole-body vibration for the employees who work in quarry and mining activities. Furthermore the vibratory phenomenon is analyzed in relation to the different types...

Indoor Environmental Quality Assessment & Monitoring

The study is developed in the field of investigation that analyzes the relationships between the Indoor Environment Quality (IEQ) and the User Global Comfort, where the Comfort is intended as the particular condition of well-being determined, on the basis of sensory perceptions of an individual in an environment, by temperature, humidity, noise level, brightness, air quality detected within the environment. The purpose of the study is to deepen the knowledge of the single factors that influence the sensory perception of different environmental conditions by an individual...

Gas Turbine Combustion Instabilities Diagnosis

Combustion of lean and preformed mixtures (Lean Premixed Combustion, LPM) is the current state of the art among the combustion technologies for stationary gas turbine plants, fuelled by natural gas. This in terms both of energy conversion efficiency both of harmful emission reduction. However, just the ultra-lean premixed flames are those most prone to thermo-acoustic instabilities, that is to the onset of large amplitude pressure fluctuations, dues to the coupling between the unsteady expansion effects of heat release fluctuations and...