DESIGN OF SMART SENSORS FOR DETECTION OF PHYSICAL QUANTITIES

Microsystems and integrated smart sensors represent a flourishing business thanks to the manifold benefits of these devices with respect to their respective macroscopic counterparts. Miniaturization to micrometric scale is a turning point to obtain high sensitive and reliable devices with enhanced spatial and temporal resolution. Power consumption compatible with battery operated systems, and reduced cost per device are also pivotal for their success. All these characteristics make investigation on this filed very active nowadays. This thesis work is focused on two main themes: (i) design and development of a single chip smart flow-meter; (ii) design and development of readout interfaces for capacitive micro-electro-mechanical-systems (MEMS) based on capacitance to pulse width modulation conversion. High sensitivity integrated smart sensors for detecting very small flow rates of both gases and liquids aiming to fulfil emerging demands for this kind of devices in the industrial to environmental and medical applications. On the other hand, the prototyping of such sensor is a multidisciplinary activity involving the study of thermal and fluid dynamic phenomenon that have to be considered to obtain a correct design. Design, assisted by finite elements CAD tools, and fabrication of the sensing structures using features of a standard CMOS process is discussed in the first chapter. The packaging of fluidic sensors issue is also illustrated as it has a great importance on the overall sensor performances. The package is charged to allow optimal interaction between fluids and the sensors and protecting the latter from the external environment. As miniaturized structures allows a great spatial resolution, it is extremely challenging to fabricate low cost packages for multiple flow rate measurements on the same chip. As a final point, a compact anemometer prototype, usable for wireless sensor network nodes, is described. The design of the full custom circuitry for signal extraction and conditioning is coped in the second chapter, where insights into the design methods are given for analog basic building blocks such as amplifiers, transconductors, filters, multipliers, current drivers. A big effort has been put to find reusable design guidelines and trade-offs applicable to different design cases. This kind of rational design enabled the implementation of complex and flexible functionalities making the interface circuits able to interact both with on chip sensors and external sensors. In the third chapter, the chip floor-plan designed in the STMicroelectronics BCD6s process of the entire smart flow sensor formed by the sensing structures and the readout electronics is presented. Some preliminary tests are also covered here. Finally design and implementation of very low power interfaces for typical MEMS capacitive sensors (accelerometers, gyroscopes, pressure sensors, angular displacement and chemical species sensors) is discussed. Very original circuital topologies, based on chopper modulation technique, will be illustrated. A prototype, designed within a joint research activity is presented. Measured performances spurred the investigation of new techniques to enhance precision and accuracy capabilities of the interface. A brief introduction to the design of active pixel sensors interface for hybrid CMOS imagers is sketched in the appendix as a preliminary study done during an internship in the CNM-IMB institute of Barcelona

Progetto di un amplificatore da strumentazione in tecnologia BCD6

I segnali d’uscita dei sensori integrati sono tipicamente a bassa potenza, in special modo se sono presenti trasduttori autogeneranti; la loro amplificazione risulta quindi critica, e tuttavia necessaria per renderli facilmente trattabili da convenzionali sistemi di condizionamento e di elaborazione. L’obiettivo di questa tesi è quello di progettare una catena di amplificazione particolarmente sensibile, in grado di leggere i segnali provenienti da un sensore di portata basato su termocoppie; sia il sensore, sia l’interfaccia di lettura verranno integrati sul solito die di silicio. Questo lavoro si suddivide in cinque capitoli: Capitolo 1 : Viene fatta una breve panoramica sui sensori integrati di portata ed è data una descrizione di massima dei principi fisici implicati nella trasduzione delle grandezze: dal flusso al segnale elettrico. Si è dedicata particolare attenzione ai sensori di portata calorimetrici ed al loro pilotaggio, in quanto il circuito qui progettato, è destinato alla lettura di questo tipo di dispositivi. Capitolo 2 : Dopo aver introdotto i fenomeni – offset e rumore flicker – che limitano la risoluzione di un amplificatore per segnali la cui banda comprenda la continua, vengono descritte le tecniche note in letteratura per eliminare o ridurre queste limitazioni. Tra le tecniche conosciute, quella pi`u efficace risulta la tecnica di stabilizzazione a chopper: questa permette di ottenere un offset idealmente nullo ed un livello di rumore, in banda base, pari al rumore broad band dell’amplificatore, ossia il minimo possibile. E' quindi introdotta l’architettura adottata, composta da un amplificatore chopper e da un filtro passa-basso, oggetti di studio nei successivi capitoli. Capitolo 3 : Viene esplorato lo spazio di progetto dell’amplificatore chopper, con particolare attenzione al rumore che esso introduce, ed alla sensibilità del guadagno rispetto alle variazioni di temperatura e dei parametri di processo. Sono ricavati alcuni limiti teorici al minimo rumore introdotto dall’amplificatore, i quali hanno condizionato le scelte progettuali ed il dimensionamento del circuito. Dopo aver adottato alcune specifiche, come la densità di potenza di rumore riferita all’ingresso, è stato fatto un dimensionamento che ottimizza nel contempo il consumo di potenza e l’ingombro; sono stati quindi verificati i parametri più importanti che determinano le prestazioni del sistema, sia tramite simulazioni Monte Carlo, sia confrontando i risultati nominali con quelli ottenuti considerando la variabilità dei modelli dei dispositivi (corners). Si è tenuto di conto degli effetti di non linearità dell’amplificatore e della massima amplificazione ottenibile, in relazione ai limiti di dinamica del filtro in cascata. Saranno ricavati alcuni limiti teorici al minimo rumore introdotto dall'amplificatore i quali orienteranno le scelte progettuali ed il dimensionamento del circuito. Capitolo 4 : Poiché lo stadio di amplificazione impiega una tecnica di riduzione del rumore basata sulla modulazione dei segnali, è necessario rimuovere le componenti spettrali indesiderate tramite un opportuno filtraggio. In questo capitolo verranno esposti i criteri di dimensionamento del filtro preposto a questa operazione. Anche in questo caso è stato verificato il comportamento del sistema, in presenza di offset e di variazioni di temperatura. Capitolo 5 : Sono mostrate le prestazioni, ricavate per via simulativa, del sistema complessivo. Tali simulazioni sono volte a garantire la fattibilità del circuito, specialmente in presenza di errori di processo. Inoltre si è verificato che il rumore riportato all’ingresso di tutto il sistema, risultasse effettivamente quello desiderato

Convenient and Sensitive Measurement of Lactosylceramide Synthase Activity Using Deuterated Glucosylceramide and Mass Spectrometry

Lactosylceramide is necessary for the biosynthesis of almost all classes of glycosphingolipids and plays a relevant role in pathways involved in neuroinflammation. It is synthesized by the action of galactosyltransferases B4GALT5 and B4GALT6, which transfer galactose from UDP-galactose to glucosylceramide. Lactosylceramide synthase activity was classically determined in vitro by a method based on the incorporation of radiolabeled galactose followed by the chromatographic separation and quantitation of the product by liquid scintillation counting. Here, we used deuterated glucosylceramide as the acceptor substrate and quantitated the deuterated lactosylceramide product by liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS). We compared this method with the classical radiochemical method and found that the reactions have similar requirements and provide comparable results in the presence of high synthase activity. Conversely, when the biological source lacked lactosylceramide synthase activity, as in the case of a crude homogenate of human dermal fibroblasts, the radiochemical method failed, while the other provided a reliable measurement. In addition to being very accurate and sensitive, the proposed use of deuterated glucosylceramide and LC-MS/MS for the detection of lactosylceramide synthase in vitro has the relevant advantage of avoiding the costs and discomforts of managing radiochemicals

Conferimento della Laurea magistrale ad honorem in scienze archivistiche e biblioteconomiche a Michele Casalini / Award of the Laurea magistrale ad honorem in Library and information Science to Michele Casalini

On the 21st May 2019, the University of Florence awarded Michele Casalini an honorary degree for his dedication and his important contribution in the field of Library and Archival Sciences. The ceremony, which was held in the Rectorate's Aula Magna in Florence, represents the first recognition of merit for modern library science and the second for library and archival sciences to ever be granted by an Italian university. The text features the complete speeches by Luigi Dei, Rector, by Andrea Zorzi, Director of the SAGAS Department, the Laudatio by Mauro Guerrini, president of the Degree in Library and Archival Sciences and the Lectio Doctoralis by Michele Casalini, entitled La centralità delle biblioteche per il progresso e la democrazia. All the texts are published in Italian and English

Variable-Mirror Amplifier: A New Family of Process-Independent Class-AB Single-Stage OTAs for Low-Power SC Circuits

Peer reviewe

A Robust 96.6-dB-SNDR 50-kHz-Bandwidth Switched-Capacitor Delta-Sigma Modulator for IR Imagers in Space Instrumentation

Infrared imaging technology, used both to study deep-space bodies' radiation and environmental changes on Earth, experienced constant improvements in the last few years, pushing data converter designers to face new challenges in terms of speed, power consumption and robustness against extremely harsh operating conditions. This paper presents a 96.6-dB-SNDR (Signal-to-Noise-plus-Distortion Ratio) 50-kHz-bandwidth fourth-order single-bit switched-capacitor delta-sigma modulator for ADC operating at 1.8 V and consuming 7.9 mW fit for space instrumentation. The circuit features novel Class-AB single-stage switched variable-mirror amplifiers (SVMAs) enabling low-power operation, as well as low sensitivity to both process and temperature deviations for the whole modulator. The physical implementation resulted in a 1.8-mm 2 chip integrated in a standard 0.18-μm 1-poly-6-metal (1P6M) CMOS technology, and it reaches a 164.6-dB Schreier figure of merit from experimental SNDR measurements without making use of any clock bootstrapping, analog calibration, nor digital compensation technique. When coupled to a IR imager, the current design allows more than 50 frames per minute with a resolution of 16 effective number of bits (ENOB) while consuming less than 300 mW

Radar detection of pedestrian-induced vibrations on Michelangelo’s David

This paper summarizes the results of a two-day dynamic monitoring of Michelangelo's David subject to environmental loads (city traffic and pedestrian loading induced by tourists visiting the Accademia Gallery). The monitoring was carried out by a no-contact technique using an interferometric radar, whose effectiveness in measuring the resonant frequencies of structures and historic monuments has proved over the last years through numerous monitoring activities. Owing to the dynamic behavior of the measurement system (radar and tripod), an accelerometer has been installed on the radar head to filter out the movement component of the measuring instrument from the measurement of the David's displacement. Measurements were carried out in the presence and absence of visitors, to assess their influence on the dynamic behavior of the statue. A numerical model of the statue was employed to evaluate the experimental results

Impact of lipid sources on quality traits of medical cannabis-based oil preparations

The feasibility of the use of two lipid sources and their impact on the cannabinoid profile, terpene fingerprint, and degradation products in medical cannabis oil preparations during 3 months of refrigerated storage time were investigated. LCHRMS-Orbitrap® and HS-SPME coupled to GC-MS for the investigation of targeted and untargeted cannabinoids, terpenes, and lipid degradation products in Bedrocan® and Bediol® macerated oils were used as analytical approaches. As regards the cannabinoid trend during 90 days of storage, there were no differences between PhEur-grade olive oil (OOPH) and medium-chain triglycerides oil (MCT oil) coupled to a good stability of preparations for the first 60 days both in Bedrocan® and Bediol® oils. MCT lipid source extracted a significant concentration of terpenes compared to olive oil. Terpenes showed a different scenario since MCT oil displayed the strongest extraction capacity and conservation trend of all compounds during the shelf life. Terpenes remained stable throughout the entire storage period in MCT formulations while a significant decrease after 15 and 30 days in Bediol® and Bedrocan® was observed in olive oil. Therefore, MCT oil could be considered a more suitable lipid source compared to olive oil involved in the extraction of medical cannabis for magistral preparations.Fil: Ramella, Alberto. Farmacia Dott.ri Giuliana E Alberto Ramellasas; ItaliaFil: Roda, Gabriella. Università degli Studi di Milano; ItaliaFil: Pavlovic, Radmila. Universita Degli Studi Di Milano. Medicina Veterinaria. Dipartimento Di Scienze Veterinarie Per la Salute.; ItaliaFil: Cas, Michele Dei. Università degli Studi di Milano; ItaliaFil: Casagni, Eleonora. Università degli Studi di Milano; ItaliaFil: Mosconi, Giacomo. Universita Degli Studi Di Milano. Medicina Veterinaria. Dipartimento Di Scienze Veterinarie Per la Salute.; ItaliaFil: Cecati, Francisco Miguel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Luis. Instituto de Investigaciones en Tecnología Química. Universidad Nacional de San Luis. Facultad de Química, Bioquímica y Farmacia. Instituto de Investigaciones en Tecnología Química; ArgentinaFil: Minghetti, Paola. Università degli Studi di Milano; ItaliaFil: Grizzetti, Carlo. Ospedale Di Circolofondazione Macchi, Asst Sette Laghi; Itali

Myriocin modulates the altered lipid metabolism and storage in cystic fibrosis.

Cystic fibrosis (CF) is a hereditary disease mostly related to ΔF508 CFTR mutation causing a proteinopathy that is characterized by multiple organ dysfunction, primarily lungs chronic inflammation, and infection. Defective autophagy and accumulation of the inflammatory lipid ceramide have been proposed as therapeutic targets. Accumulation of lipids and cholesterol was reported in the airways of CF patients, together with altered triglycerides and cholesterol levels in plasma, thus suggesting a disease-related dyslipidemia. Myriocin, an inhibitor of sphingolipids synthesis, significantly reduces inflammation and activates TFEB-induced response to stress, enhancing fatty acids oxidation and promoting autophagy. Myriocin ameliorates the response against microbial infection in CF models and patients' monocytes. Here we show that CF broncho-epithelial cells exhibit an altered distribution of intracellular lipids. We demonstrated that lipid accumulation is supported by an enhanced synthesis of fatty acids containing molecules and that Myriocin is able to reduce such accumulation. Moreover, Myriocin modulated the transcriptional profile of CF cells in order to restore autophagy, activate an anti-oxidative response, stimulate lipid metabolism and reduce lipid peroxidation. Moreover, lipid storage may be altered in CF cells, since we observed a reduced expression of lipid droplets related proteins named perilipin 3 and 5 and seipin. To note, Myriocin up-regulates the expression of genes that are involved in lipid droplets biosynthesis and maturation. We suggest that targeting sphingolipids de novo synthesis may counteract lipids accumulation by modulating CF altered transcriptional profile, thus restoring autophagy and lipid metabolism homeostasis

Key pedagogical and technological factors for effective blended learning design

This is a report by the expert pools of the EMPOWER programme established by EADTU to cover the latest trends and developments in new modes of teaching. New modes of teaching and learning create new opportunities for enhancing the quality of the learning experience in on campus programmes, reaching out to new target groups off campus and offering freely accessible courses nationally or worldwide through the internet. They enhance the quality, visibility and reputation of the institution.Co-funded by the Erasmus+ Programme of the European Unioninfo:eu-repo/semantics/publishedVersio