Dissertations / Theses on the topic 'Application des DPI'

Dans cette thèse, j'ai abordé les dispositions d'application des droits de propriété intellectuelle de trois accords d'association (AA), que l'Union européenne (UE) a conclus avec la Géorgie, la Moldavie et l'Ukraine au début des années 2010. J'ai puisé dans ces AA en tant que représentants de la politique extérieure souvent critiquée de l'UE en matière de propriété intellectuelle (PI), lancée en 2004, qui consiste à exporter les règles internes de l'UE en matière de propriété intellectuelle par le biais d'accords commerciaux. Cette analyse m'a permis d'aborder la question fondamentale de cette thèse : y a-t-il quelque chose de bon dans les accords commerciaux de l'UE ? La réponse claire, appuyée par cette thèse sur l'exemple des AA, est « oui ». L'enquête générale, qui a conduit à ces conclusions, était triple. Premièrement, j'ai analysé la politique générale de l'UE envers la Géorgie, la Moldavie et l'Ukraine concernant l'application des droits de propriété intellectuelle, ainsi que sa perception dans la littérature académique. Deuxièmement, après avoir retracé les critiques académiques existantes sur les accords commerciaux de l'UE, j'ai examiné si ces critiques étaient justifiées, telles qu'appliquées aux trois AA. Troisièmement, sur la base de cette analyse, j'ai identifié des problèmes supplémentaires auxquels les pays tiers pourraient être confrontés lors de la mise en oeuvre d'un accord commercial avec l'UE
In this thesis, I have addressed the IPR enforcement provisions of three Association Agreements (AAs), which the European Union (EU) concluded with Georgia, Moldova and Ukraine in the early 2010s. I drew on these AAs as representatives of the EU's often criticized external intellectual property (IP) policy, launched in 2004, which consists of exporting the EU's internal IP rules through trade agreements. Said analysis allowed me to approach the fundamental question of this thesis: is there something good with the EU trade agreements? The plain answer, supported by this thesis on the example of the AAs, is “yes”. The general investigation, which led to these conclusions, was threefold. First, I analyzed the general policy of the EU towards Georgia, Moldova and Ukraine regarding the enforcement of IPRs, as well as its perception in the academic literature. Second, after tracing existing academic criticism of the EU's trade agreements, I examined whether such criticism was justified, as applied to the three AAs. Third, based on this analysis, I identified additional problems that third countries might face when implementing a trade agreement with the EU

Programmable reversible logic is emerging as a prospective logic design style for implementation in modern nanotechnology and quantum computing with minimal impact on circuit heat generation. Adiabatic logic is a design methodology for reversible logic in CMOS where the current flow through the circuit is controlled such that the energy dissipation due to switching and capacitor dissipation is minimized. Recent advances in reversible logic using and quantum computer algorithms allow for improved computer architectures. Production of cost-effective Secure Integrated Chips, such as Smart Cards, requires hardware designers to consider tradeoffs in size, security, and power consumption. In order to design successful security-centric designs, the low-level hardware must contain built-in protection mechanisms to supplement cryptographic algorithms such as AES and Triple DES by preventing side channel attacks, such as Differential Power Analysis (DPA). Dynamic logic obfuscates the output waveforms and the circuit operation, reducing the effectiveness of the DPA attack. Significant research exists in the design and analysis of locally optimal adiabatic elements towards mitigation of side channel attacks. However, none of these works have addressed the use of adiabatic logic in implementation of flexible and programmable hardware security policies. Nor has adiabatic logic been employed in hardware security applications such as trustworthy voting systems and data encryption standards. In this dissertation, I address theory, synthesis, and application of adiabatic and reversible logic circuits for security applications. First, two major debates in reversible computing are addressed. These debates must be addressed in order to devise computational logic primitives in any emerging quantum computing technology. First, we address whether charged based computing is limited due to the use of charge as a state variable. We propose the use of body biasing in CMOS adiabatic systems as a design methodology for reducing the need for gradually changing the energy barriers. Simulation results in HSPICE at 22nm are presented which show behavior of a source-memory device operating at sub-Landauer operation. Second, we address whether reversible logic can be used to design sequential computing structures, such as memory devices. we present an analysis of Quantum Turing Machines with sequential reversible logic structures, to show that the entropy gain is substantially less than the Landauer Barrier of kTln(2), which is the limiting factor for irreversible computing. A mathematical proof is presented showing bit erasure does not occur in sequential reversible logic structures, and that these devices are physically reversible as long as appropriate delay elements are inserted in the feedback paths to prevent race conditions. This proof validates implementation of sequential reversible logic towards ultra-low power computing. Next, a novel algorithm for synthesis of adiabatic circuits in CMOS is proposed. This approach is unique because it correlates the offsets in the permutation matrix to the transistors required for synthesis, instead of determining an equivalent circuit and substituting a previously synthesized circuit from a library. Parallelism is used, and the bijective properties of the device to achieve synthesis of the logic structure in O(n) time. Then, using the ESPRESSO heuristic for minimization of Boolean functions method on each output node in parallel, we optimize the synthesized circuit. It is demonstrated that the algorithm produces a 32.86% improvement over previously synthesized circuit benchmarks. For stronger mitigation of DPA attacks, we propose the implementation of Adiabatic Dynamic Differential Logic for applications in secure IC design. Such an approach is effective in reducing power consumption, demonstrated using HSPICE simulations with 22nm predictive technology. The benefits of our design are demonstrated by comparing instantaneous power waveforms and observing the magnitude of differential power spikes during switching events. First, simulation results for body-biasing on sub-threshold adiabatic inverters show an improvement in differential power up to 43.28% for similar inverters without body biasing. Then, a High Performance Adiabatic Dynamic Differential Logic (PADDL) is presented for an implementation in high frequency secure ICs. This method improves the differential power over previous dynamic and differential logic methods by up to 89.65%. Finally, we propose a Body-Biased Adiabatic Dynamic Differential Logic (BADDL) for ultra-low power applications. Simulation results show that the differential power was improved upon by a factor of 199.16. Then, we present an adiabatic S-box which significantly reduces energy imbalance compared to previous benchmarks. The design is capable of forward encryption and reverse decryption with minimal overhead, allowing for efficient hardware reuse.

El texto completo de este trabajo no está disponible en el Repositorio Académico UPC por restricciones de la casa editorial donde ha sido publicado.
The most visible expression of violence against women is feminicide. The majority of feminicide cases are committed by the partner or former partner of the victim. This involves ongoing domestic abuses, threats or intimidation, sexual violence or situations in which women have less energy or resources than their partner. In addition, clinics, public hospitals or private health institutes have mental health evaluation processes, however, these flows are usually carried out in several sessions, which causes a delay in the diagnosis. In this article, a mobile application that supports psychologists or psychiatrists during the process of the psychological profile diagnosis is proposed. The system contains a questionnaire and psychological tests, in this way, based on the patient responses, indicators, and metrics, the psychological profile of the assailant is obtained as a result. The use of the system in 40 patients shows that the selection times and the psychological test qualification have improved, as well as the interpretation of the results and the total process of diagnosis, which, when obtained at opportune time, allows specialists to prevent the victim from a possible feminicide.

Tenere traccia delle proprie entrate e delle proprie uscite monetarie può risultare molto utile se si vogliono avere degli indicatori sulla qualità della gestione del proprio denaro. In questo testo viene presentata un'applicazione per dispositivi Android con la quale l'utente può salvare tutti i suoi movimenti monetari, con la possibilità di condividerli con altri utenti e di effettuare previsioni su eventi futuri.

BEC è un sistema sviluppato per la gestione della sicurezza del dipendente durante lo svolgimento del lavoro. Oltre il principale compito di monitoraggio, il sistema cerca di migliorare l'esperienza lavorativa dei dipendenti all'interno dell'azienda attraverso l'utilizzo delle nuove tecnologie.

This PhD thesis deals with the exploitation of heterogeneous photocatalysis, as an Advanced Oxidation Process, for environmental issues related to the emerging pollution: in particular for wastewater remediation and bacterial decontamination purposes. During this project, several photocatalytic materials have been synthesized by coupling semiconductor (TiO2) nanoparticles (both bare and doped) to different supporting materials, e.g. persistent luminescence materials (3ZnO:Ga2O3:2GeO2: Cr3+; CaAl2O4: (La, Nd)3+), magnetic and porous materials (ferrite nanoparticles, magnetic zeolite obtained from industrial waste) and polymeric materials (based on polydimethylsiloxane “PDMS”). In addition, an analytical approach to the study on the abatement and the quantification of emerging pollutants was considered, an important part of which was carried out at the Water Lab of the Environmental Engineering Department at Technical University of Crete, under the supervision of Professor Elia Psillakis. Specifically, TiO2 was synthesized through the sol-gel technique, both in the undoped and doped form (for example with Cu and N), while its crystallization on several supporting materials was obtained with different synthetic techniques such as: sol-gel synthesis, solid-state synthesis, hydrothermal/solvothermal synthesis and electrospinning technique. Some of the synthesized materials were investigated using a chemometric approach, that is the possibility to exploit an Experimental Design mathematical model in order to investigate the optimal synthetic conditions to get enhanced photocatalytic efficiency (within the experimental domain) for the materials. All samples synthesized within the current project were subjected to a physical-chemical characterization, by means of: X-Ray Diffraction “XRD” and crystallographic refinements (Rietveld, Pair Distribution Function “PDF”, Williamson-Hall plot), Scanning and Transmission Electron Microscopy-Energy Dispersive X-Ray Spectrometry “SEM-EDS”, “TEM”, Porosimetry Brunauer-Emmett-Teller “BET”, Dynamic Light Scattering “DLS”, Differential Scanning Calorimetry “DSC”, Diffuse Reflectance (Kubelka-Munk plots for Energy Gap “Eg”), Rheological Measurements, Luminescence Properties, Turbidimetry, Inductively Coupled Plasma – Atomic Emission Spectroscopy “ICP-AES”, Diffuse Reflectance Infrared Fourier Transform Spectroscopy “DRIFTS” and antibacterial properties with E. Coli cultures. Above all, a kinetic characterization in terms of photocatalytic efficiency evaluation was always performed for synthesized samples. In particular, kinetic behaviour of the photocatalysts was evaluated by means of Methylene Blue “MB” aqueous solutions degradation, studied as a function of time, with different initial concentrations (as required by ISO NORM 10678:2010). For MB quantification, a UV-Vis spectrophotometer was used, and experiments were usually performed in triplicate. Furthermore, during the first part of the project, a Pilot Plant Prototype was assembled (with a processing volume equal to 1L) and used for preliminary evaluations on a potential industrial scale-up. All tests and characterizations achieved were adapted according to the specific supporting material employed. Eventually, considering the nature of emerging micro-pollutants, an analytical approach to the determination of their concentration in aqueous systems was employed. Specifically, chromatographic tests were performed with liquid and gas chromatography techniques, often coupled with mass spectrometry, for some specific emerging pollutants (Ofloxacin, Parabens, Nicotine, Salbutamol). Matrix effects were also considered in the evaluation of the pollutants’ degradation during the advanced oxidation tests. This task wouldn’t have been possible without valuable National and International collaborations, which gave an essential help to the development of the project for what concerns a part of the reported characterization. My acknowledgements are directed to: Department of Chemistry and Industrial Chemistry - University of Genova (Analytical, Industrial, Physical Sections), Analytic and Photochemistry Section of the Department of Chemistry - University of Pavia; Department of Chemistry - University of Kuwait; Department of Environmental Engineering - Technical University of Crete; Institute of Methodologies of Environmental Analysis, Institute of Matter and Institute of Superconducting and other Innovative Materials and Devices - National Research Council. Each individual contribute will be highlighted in each dedicated section, throughout the manuscript.

2010 - 2011
The aim of the present PhD project was to design inhalable powder-based formulations for pharmaceutical products that may improve the treatment of pulmonary diseases, mainly cystic fibrosis, and may be easier for patients to use. Particularly, the present project aims to supply CF patients with flavonoids (Naringin) and aminoglycosides (Gentamicin sulfate) in a respirable form as a valid alternative over more conventional (oral or parenteral) anti-inflammatory and antibiotic therapy. As a matter of fact, in CF epithelial cells, antioxidant defense systems appear to be defective in their ability to control the amount of ROS produced and over abundance of ROS may cause tissue injury-events and modify intracellular signalling pathways leading to enhanced inflammatory processes, typical of CF airways. Overall, evidence suggests improved CFTR function in vitro when flavonoids, such as genistein, are used. For chronic Pseudomonas aeruginosa (Pa) infections in CF, gentamicin given by pulmonary route may plays important role. In fact, it was observed daily inhalation of some aminoglycosides from nebulized solution delays the acquisition of chronic Pa infections and decreases CF progression. The project address a number of the key features that are outstanding in inhaled delivery, mainly - characteristic of the active drug; - properties of the drug formulation, particularly powder flow, particle size, shape, surface properties and drug/carrier interaction; - consistent dose delivery and high proportion of dose getting to the lung; - performance of the inhaler device, including aerosol generation and delivery. A balance among these characteristics is necessary in the design of a drug formulation intended for pulmonary administration. Utilizing proven (Spray-drying) or innovative (Supercritical Assisted Atomization) technology, stable and micronized powders usefull for dry powder inhaler (DPI) production have been developed. Moreover, the research has been based on in vitro product test methods to evaluate the health effects of produced powders and their aerodynamic behaviour through the pulmonary system. Optimized stability and bioavailability of the selected drugs, the achieving of therapeutically effective concentrations for the pulmonary care of cystic fibrosis have been other goals of the research. Technologies and products that the research is aimed to develop would be of interest to a number of pharmaceutical companies either in the respiratory area or trying to get a toehold in this market. Specific objectives of this research have been: design and development of Dry Powder Inhalers (DPIs) containing flavonoids (Naringin) or aminoglycoside antibiotics (Gentamicin sulfate) micronized powder by spray drying production or by Supercritical Assisted Atomization (SAA); optimization of the aerodynamic characteristics of the powders, through the use of excipients (amino acids) not toxic for lung but able to improve the powder flow properties and dispersion which, in turn, may increase lung deposition of the drugs; in vitro evaluation of the biological activity of the engineered particles on a model of bronchial epithelial cell lines from patients with cystic fibrosis (CuFi1, F508del/F508del CFTR), in comparison to the activity of the same products on normal bronchial epithelial cell lines (NuLi1). (edited by author)
X n.s.

Con una proiezione di crescita annuale del 20 per cento, il settore farmaceutico in Cina appare destinato a superare il Giappone quale seconda maggiore potenza del settore entro il 2015.Tuttavia, sebbene la percentuale della spesa sanitaria sul Pil totale sia attualmente soltanto di circa un 5 per cento, ciò che preoccupa è che quasi un 50 per cento di questa è dovuto alle spese in medicinali. Per questo motivo negli ultimi anni, il Governo è impegnato a riformare il sistema, attraverso normative e regolamentazioni volte al controllo e al monitoraggio dei prezzi. Gli effetti di questi interventi governativi, tuttavia, per una serie di ragioni, risultano essere ancora poco soddisfacenti ed è necessario pensare a delle strategie alternative per limitare la spesa medica che va a pesare sulle spalle dei singoli pazienti.

Descrizione di un'applicazione web che offre un servizio di backup del proprio Google Drive, sia completo che personalizzato. Nella tesi vengono spiegati i requisiti, l'architettura e il funzionamento del software, approfondendo le tecnologie utilizzate per lo sviluppo e le difficoltà riscontrate.

In the past few years, significant progress in the study of scaffolds for cells grow has taken place. This research has led to the development of a wide variety of metallic, polymeric, ceramic and composite biomaterials. This thesis describes the development of a novel composite system with tunable morphological and mechanical properties, ease of production and capability to guide the biological response. The composite system was composed by polyamide 6 (PA6) and carboxyl-functionalized multi-walled carbon nanotubes (MWCNT), which were used as reinforcement agents in the polymer matrix. Electrospinning was used as the fabrication technique for the production of anisotropic networks. Physical and biological properties of the nets were evaluated focusing on the effect of the filler addition. It was observed that the production technique induced the alignment of MWCNT within the nanofiber axis and the formation of a roughness on the fiber's surface. The biological properties of MG63 and MRC5 cell lines were enhanced if compared with the neat PA6 networks due to surface modification caused by the filler addition.

Il lavoro svolto si concentra sulla progettazione e realizzazione di un sistema per il calcolo dei consumi sotto forma di un'applicazione Android con l'obiettivo di sensibilizzare gli automobilisti ad una guida più eco-sostenibile. L’applicazione dovrà essere innanzitutto in grado di visualizzare i consumi istantanei di un veicolo. Per ottemperare a questa richiesta l'applicazione dovrà comunicare con la centralina dell'automobile, richiedendo i parametri necessari al calcolo dei consumi per poi visualizzare il risultato real-time al conducente. L'applicazione inoltre dovrà fornire un semplice social-network dove i diversi utenti potranno condividere i percorsi effettuati con la propria automobile e i relativi consumi medi. Durante lo sviluppo di questo elaborato particolare attenzione sarà data agli Automotive Embedded System proiettandoli nell'ottica della Smart Mobility e delle Smart City. Il focus sarà rivolto alla comunicazione con la centralina di un veicolo tramite interfaccia OBD-II di cui vedremo possibilità, limiti e alternative. Ci soffermeremo sull'analisi dei dati provenienti da una centralina, studiandone le funzionalità al fine di comprendere come utilizzare i parametri da essa ricavati. Si vedrà come integrare in un'applicazione Android le diverse opzioni disponibili attraverso i Google Play Services e come costruire un social network sfruttando Firebase, un backend fornito da Google come PaaS, costruito sulla Google Cloud Platform. Inoltre si vedrà come adottare un approccio user-centered nello sviluppo della user-interface dell’applicazione al fine di massimizzare la user-experience durante l’utilizzo della stessa.

Polyhydroxyalkanoates (PHAs) are a group of biobased, biodegradable and biocompatible polyesters, synthetized, through fermentation processes, by bacterial enzymes from various feedstock, e.g. agricultural wastes, that represent a promising alternative to currently used petroleum-based polymers. Among various produced PHAs, poly(3-hydroxybutyrate) (PHB) and the copolymer poly(3-hydroxybutyarte-co-3-hydroxyvalerate-co-4-hydroxyvalerate) (PHBVV) are nowadays intensively studied. Such polyesters are intriguing candidates as fully biobased and biodegradable polymeric matrix, which can be reinforced to obtain composites with enhanced thermal and mechanical properties. Using a novel approach, water-suspended micro-fibrillated cellulose (MFC) was dispersed into a PHA matrix through thermo-mechanical mixing by using a suitable polymeric dispersing agent. SEM images confirms obtainment of good dispersion and encourage further investigation. Furthermore, considering biocompatibility of PHAs, realization of PHB and PHBVV scaffolds for tissue engineering, filled with osteoinductive inorganic particles, were prepared. Preliminary in vitro investigations showed promising results and further analyses are currently ongoing. To improve and tune intrinsic excellent PHAs properties, and possibly extend polyesters applications, post-polymerization macromolecular chains modifications were attempted. After a PHB and PHBVV fully characterization by conventional chromatographic, thermal and spectroscopic analyses, a more complete characterization has been achieved by end-groups analyses through a herein proposed new 19F-NMR method, which allows to overcome typical disadvantages and drawbacks of traditional techniques. The 19F-NMR method reveled to be a simple and fast analytical tool for characterizing PHB derivatives and planning further reactions to obtain useful PHB-based macromonomers, as the herein presented UV-sensible PHB-based segments. Following the successful utilization of PHB-based cross-linking agent mixed with a liquid commercial methacrylate monomer in stereolithography 3D printing, demonstrating the real possible application of the synthesized material, a new green solvent-free preparation procedure was established. In this dissertation, a wide range of possible methodologies for PHAs properties modification have been proposed and all prepared materials can be envisioned in several various technological applications.

In the past few years, significant progress in the study of scaffolds for cells grow has taken place. This research has led to the development of a wide variety of metallic, polymeric, ceramic and composite biomaterials. This thesis describes the development of a novel composite system with tunable morphological and mechanical properties, ease of production and capability to guide the biological response. The composite system was composed by polyamide 6 (PA6) and carboxyl-functionalized multi-walled carbon nanotubes (MWCNT), which were used as reinforcement agents in the polymer matrix. Electrospinning was used as the fabrication technique for the production of anisotropic networks. Physical and biological properties of the nets were evaluated focusing on the effect of the filler addition. It was observed that the production technique induced the alignment of MWCNT within the nanofiber axis and the formation of a roughness on the fiber's surface. The biological properties of MG63 and MRC5 cell lines were enhanced if compared with the neat PA6 networks due to surface modification caused by the filler addition.

L'objet de cette thèse est l'étude de la déposition de particules colloïdales dans un dispositif utilisé dans l'industrie, le dip-coating, qui consiste à plonger un substrat dans un bain de suspension colloïdale, et à l'en retirer à vitesse constante. Ce dispositif fait intervenir trois phénomènes, dont l'importance est prépondérante dans la même zone, à proximité de la ligne de contact: l'évaporation, présentant une singularité à la ligne triple, l'hydrodynamique, présentant une divergence des contraintes visqueuses à cette même ligne, et le dépôt de particules. Dans une première partie, nous nous sommes intéressés à l'évaporation d'un liquide pur, dont la ligne de contact est en mouvement. Nous avons pu donner de nouvelles lois de Voïnov (en mouillage partiel) et de Tanner (en mouillage total), prenant en compte l'évaporation, et pouvant expliquer les difficultés observées dans les mesures d'angles de contact. Enfin, nous avons pu isoler une longueur, appelée longueur de capture, grâce à une situation de flux nul. Dans une seconde partie, nous nous sommes penchés sur le cas classique de la "tache de café", où la ligne de contact est fixe, mais où il y a présence de particules. Nous avons pu isoler différentes phases de croissance du dépôt solide de particules, ainsi que la formation par flambage ou fluage de la surface de structures organisées à l'échelle microscopiques. Dans une troisième partie, nous avons étudié le dispositif de dip-coating proprement dit. Cette étude nous a permis de mettre en évidence un minimum dans l'épaisseur de particules déposées, et d'expliquer un nouveau régime de déposition appelé "régime évaporatif", grâce au concept de ligne de capture.

Trovare una fonte alternativa ai combustibili fossili non costituisce più una scelta, ma un obbligo. Lo sfruttamento dell’energia geotermica sta diventando una realtà sempre più diffusa, in quanto una forma di energia rinnovabile, pulita, economicamente conveniente, e con una giusta politica energetica potrebbe dare il suo importante contributo all’energia ottenuta da fonte rinnovabile. Ci sono però dei fattori da non sottovalutare, l’installazione e il funzionamento di impianti geotermici per il riscaldamento o raffrescamento di edifici può produrre alterazioni sull’ambiente circostante e nella falda acquifera. Attraverso un attento studio vengono presi in considerazione tutti i fattori che potrebbero provocare un cambiamento dell’equilibrio preesistente, e vengono individuate le soluzioni che permettono la fattibilità del progetto rispettando i parametri imposti dalla legge. Nell’istallazione di sistemi geotermici a bassa entalpia, il principale elemento da tenere sotto osservazione riguarda la previsione e il controllo delle temperature, in modo tale da impedire lo sviluppo di anomalie termiche. Il sistema preso in considerazione in questa tesi è un sistema geotermico open loop: attraverso un pozzo di adduzione viene prelevata acqua direttamente dalla falda acquifera, per il riscaldamento o il raffrescamento di un edificio, e reimmessa, ad una temperatura diversa, attraverso un pozzo di reimmissione. Si valuta l’impatto del sistema nel sottosuolo e le temperature raggiunte a seguito della messa in opera dell’impianto. In particolare, è proposto un modello numerico MODFLOW di un sistema open loop in un acquifero di sabbia e ghiaia, al fine di determinare l’influenza della reimmissione dal punto di vista idrico e termico. I dati risultanti da questo modello saranno confrontati con quelli ottenuti utilizzando un potente software, COMSOL MULTIPHYSICS. Infine si effettua l’analisi e il confronto dei dati ottenuti dai due software nelle diverse configurazioni del sistema e se ne individua la più adatta alle caratteristiche del sito in esame.

Gelatine, which is produced by collagen partial hydrolysis, has been largely used in the biomedical field for a wide variety of applications, which are ranging from drug delivery to wound healing. Its spread depends strongly on its biocompatibility: this natural polymer is indeed non-toxic, non-carcinogenic, non-immunogenic, enzymatically degradable and bioresorbable. In the biomedical field gelatine is mostly used as highly concentrated hydrogel (with a melting point above 43 °C - 45 °C) or cross-linked. This work investigated the use of uncross-linked gelatine hydrogels, with a melting temperature in the physiological range, for different biomedical applications. Firstly, it was studied the possibility to produce a solid hydrogel to use as easily removable wound dressing. Once applied to a wound, this patch keeps a moist environment in order to improve the regeneration, while releasing drugs or bioactive factors that it could be preloaded of. Moreover, it can be easily removed, without damages to the wound site and the newly formed tissue, by washing with warm sterile water (37 °C - 39 °C). Secondly, the gelatine material was investigated as substrate for the so-named cell sheet engineering. With our procedure cell sheets can be grown on the gelatine gel and, successively, they can be integrally transferred to a different surface, with gelatine being removed by melting at 37 °C, without any proteolytic enzyme. The gelatine sheet supporting cells, differently from the “Okano†cell sheet method, could be also directly implanted in-vivo without any need for removal, due to the gentle melting of the gelatine sheet after implantation. Thirdly, gelatine gels were used as depot to release pro-angiogenic factors in-vivo. Due to their ability to absorb aqueous solutions and release them while dissolving / degrading, gelatine gels were loaded with Amniotic Fluid Stem Cells Conditioned Medium and used to evaluate the effect of grow factors in a model of ischemic fasciocutaneous flap. Additionally, in order to evaluate the in-vivo degradation rate of gelatine gels loaded with Platelet Rich Plasma, a preliminary test was performed. The results of this test suggested the possibility to employ the gel films as antiadhesive membranes in surgery.

The repair or replacement of damaged or diseased hard tissue is a biomedical field that has been the subject of more and more interest in many areas of research and especially in the development of new biomaterials. The rise in the average age of the world population, increasing osteoporosis treatments and the spread of cancer and genetic bone diseases, has brought about the need to find solutions for patient care. To achieve this target/objective, biomaterials must simulate the body environment as much as possible and favour tissue repair by integrating them into the host site. Calcium phosphates are used as medical implants because they have a chemical composition similar to the mineral of human bones, i.e. apatite. For this reason they are biocompatible and they can interact in a bioactive way with bone tissue. In the present work a specific form of bone graft, in the form of calcium phosphate granules, has been developed by using the droplet extrusion technique. The granules were characterized chemically and physically, with specific attention to in vivo and in vitro analyses. The proposed method has allowed us to obtain spherical granules in very narrow micrometric size distribution (300-1200 μm) without the use of solvents or oils thus avoiding time consuming washing processes. Granules were produced with several controlled mineralogical compositions including: pure Hydroxyapatite (HA) and β-Tricalcium Phosphate (βTCP), mixtures of HA/βTCP and Hydroxyapatite/Tetracalcium phosphate (HA/TTCP), and compositions doped with zinc (for antibacterial purposes) and strontium (for anti-osteoporosis purposes). Of several interesting features, the produced granules show high interconnected microporosity (0.1-10 μm) and surface roughness, properties necessary for osteoconductivity. The solubility behavior of granules was studied and demonstrated that the morphology and microporosity are more important in dissolution processes than chemical or mineralogical composition. Products were tested in simulated body fluid (SBF), and among the different compositions, HA/TTCP has been found to be bioactive during in vitro studies. In fact an intense precipitation of a carbonated layer of apatite was observed, associated with the high dissolution of a TTCP phase. All pure granules were demonstrated to not be cytotoxic. Bone implantations in different animal models (rabbits and primates) showed good performance of granules in the repairing of bone. The granules stimulated the bone growth without any inflammatory reactions. In particular, HA/TTCP granules exhibited excellent biomechanical properties by increasing the stability of neo-formed bone. These preliminary investigations were sufficient to show that the developed granules can be used for bone repair or replacement. However, more studies, especially for doped products, such as in vitro cells experiments, have to be performed to assure the biocompatibility and the effective stimulation of bone growth. This work was performed in collaboration with Eurocoating S.p.A. (Trento, Italy), a company expert in biomedical coatings for prostheses and implants, and it is a part of “CaP project†co-sponsored by Provincia Autonoma di Trento (Italy).

Research in art conservation has been developed from the early 1950s, giving a significant contribution to the conservation-restoration of cultural heritage artefacts. In fact, only through a profound knowledge about the nature and conditions of constituent materials, suitable decisions on the conservation and restoration measures can thus be adopted and preservation practices enhanced. The study of ancient artworks is particularly challenging as they can be considered as heterogeneous and multilayered systems where numerous interactions between the different components as well as degradation and ageing phenomena take place. However, difficulties to physically separate the different layers due to their thickness (1-200 µm) can result in the inaccurate attribution of the identified compounds to a specific layer. Therefore, details can only be analysed when the sample preparation method leaves the layer structure intact, as for example the preparation of embedding cross sections in synthetic resins. Hence, spatially resolved analytical techniques are required not only to exactly characterize the nature of the compounds but also to obtain precise chemical and physical information about ongoing changes. This thesis focuses on the application of FTIR microspectroscopic techniques for cultural heritage materials. The first section is aimed at introducing the use of FTIR microscopy in conservation science with a particular attention to the sampling criteria and sample preparation methods. The second section is aimed at evaluating and validating the use of different FTIR microscopic analytical methods applied to the study of different art conservation issues which may be encountered dealing with cultural heritage artefacts: the characterisation of the artistic execution technique (chapter II-1), the studies on degradation phenomena (chapter II-2) and finally the evaluation of protective treatments (chapter II-3). The third and last section is divided into three chapters which underline recent developments in FTIR spectroscopy for the characterisation of paint cross sections and in particular thin organic layers: a newly developed preparation method with embedding systems in infrared transparent salts (chapter III-1), the new opportunities offered by macro-ATR imaging spectroscopy (chapter III-2) and the possibilities achieved with the different FTIR microspectroscopic techniques nowadays available (chapter III-3). In chapter II-1, FTIR microspectroscopy as molecular analysis, is presented in an integrated approach with other analytical techniques. The proposed sequence is optimized in function of the limited quantity of sample available and this methodology permits to identify the painting materials and characterise the adopted execution technique and state of conservation. Chapter II-2 describes the characterisation of the degradation products with FTIR microscopy since the investigation on the ageing processes encountered in old artefacts represents one of the most important issues in conservation research. Metal carboxylates resulting from the interaction between pigments and binding media are characterized using synthesised metal palmitates and their production is detected on copper-, zinc-, manganese- and lead- (associated with lead carbonate) based pigments dispersed either in oil or egg tempera. Moreover, significant effects seem to be obtained with iron and cobalt (acceleration of the triglycerides hydrolysis). For the first time on sienna and umber paints, manganese carboxylates are also observed. Finally in chapter II-3, FTIR microscopy is combined with further elemental analyses to characterise and estimate the performances and stability of newly developed treatments, which should better fit conservation-restoration problems. In the second part, in chapter III-1, an innovative embedding system in potassium bromide is reported focusing on the characterisation and localisation of organic substances in cross sections. Not only the identification but also the distribution of proteinaceous, lipidic or resinaceous materials, are evidenced directly on different paint cross sections, especially in thin layers of the order of 10 µm. Chapter III-2 describes the use of a conventional diamond ATR accessory coupled with a focal plane array to obtain chemical images of multi-layered paint cross sections. A rapid and simple identification of the different compounds is achieved without the use of any infrared microscope objectives. Finally, the latest FTIR techniques available are highlighted in chapter III-3 in a comparative study for the characterisation of paint cross sections. Results in terms of spatial resolution, data quality and chemical information obtained are presented and in particular, a new FTIR microscope equipped with a linear array detector, which permits reducing the spatial resolution limit to approximately 5 µm, provides very promising results and may represent a good alternative to either mapping or imaging systems.

Research in art conservation has been developed from the early 1950s, giving a significant contribution to the conservation-restoration of cultural heritage artefacts. In fact, only through a profound knowledge about the nature and conditions of constituent materials, suitable decisions on the conservation and restoration measures can thus be adopted and preservation practices enhanced. The study of ancient artworks is particularly challenging as they can be considered as heterogeneous and multilayered systems where numerous interactions between the different components as well as degradation and ageing phenomena take place. However, difficulties to physically separate the different layers due to their thickness (1-200 µm) can result in the inaccurate attribution of the identified compounds to a specific layer. Therefore, details can only be analysed when the sample preparation method leaves the layer structure intact, as for example the preparation of embedding cross sections in synthetic resins. Hence, spatially resolved analytical techniques are required not only to exactly characterize the nature of the compounds but also to obtain precise chemical and physical information about ongoing changes. This thesis focuses on the application of FTIR microspectroscopic techniques for cultural heritage materials. The first section is aimed at introducing the use of FTIR microscopy in conservation science with a particular attention to the sampling criteria and sample preparation methods. The second section is aimed at evaluating and validating the use of different FTIR microscopic analytical methods applied to the study of different art conservation issues which may be encountered dealing with cultural heritage artefacts: the characterisation of the artistic execution technique (chapter II-1), the studies on degradation phenomena (chapter II-2) and finally the evaluation of protective treatments (chapter II-3). The third and last section is divided into three chapters which underline recent developments in FTIR spectroscopy for the characterisation of paint cross sections and in particular thin organic layers: a newly developed preparation method with embedding systems in infrared transparent salts (chapter III-1), the new opportunities offered by macro-ATR imaging spectroscopy (chapter III-2) and the possibilities achieved with the different FTIR microspectroscopic techniques nowadays available (chapter III-3). In chapter II-1, FTIR microspectroscopy as molecular analysis, is presented in an integrated approach with other analytical techniques. The proposed sequence is optimized in function of the limited quantity of sample available and this methodology permits to identify the painting materials and characterise the adopted execution technique and state of conservation. Chapter II-2 describes the characterisation of the degradation products with FTIR microscopy since the investigation on the ageing processes encountered in old artefacts represents one of the most important issues in conservation research. Metal carboxylates resulting from the interaction between pigments and binding media are characterized using synthesised metal palmitates and their production is detected on copper-, zinc-, manganese- and lead- (associated with lead carbonate) based pigments dispersed either in oil or egg tempera. Moreover, significant effects seem to be obtained with iron and cobalt (acceleration of the triglycerides hydrolysis). For the first time on sienna and umber paints, manganese carboxylates are also observed. Finally in chapter II-3, FTIR microscopy is combined with further elemental analyses to characterise and estimate the performances and stability of newly developed treatments, which should better fit conservation-restoration problems. In the second part, in chapter III-1, an innovative embedding system in potassium bromide is reported focusing on the characterisation and localisation of organic substances in cross sections. Not only the identification but also the distribution of proteinaceous, lipidic or resinaceous materials, are evidenced directly on different paint cross sections, especially in thin layers of the order of 10 µm. Chapter III-2 describes the use of a conventional diamond ATR accessory coupled with a focal plane array to obtain chemical images of multi-layered paint cross sections. A rapid and simple identification of the different compounds is achieved without the use of any infrared microscope objectives. Finally, the latest FTIR techniques available are highlighted in chapter III-3 in a comparative study for the characterisation of paint cross sections. Results in terms of spatial resolution, data quality and chemical information obtained are presented and in particular, a new FTIR microscope equipped with a linear array detector, which permits reducing the spatial resolution limit to approximately 5 µm, provides very promising results and may represent a good alternative to either mapping or imaging systems.

This thesis begins with providing a basic introduction of electricity requirements for small developing country communities serviced by small scale generating units (focussing mainly on small wind turbine, small Photo Voltaic system and Micro-Hydro Power Plants). Scenarios of these small scale units around the world are presented. Companies manufacturing different size wind turbines are surveyed in order to propose a design that suits the most abundantly available and affordable turbines. Different Maximum Power Point Tracking (MPPT) algorithms normally employed for these small scale generating units are listed along with their working principles. Most of these algorithms for MPPT do not require any mechanical sensors in order to sense the control parameters like wind speed and rotor speed (for small wind turbines), temperature and irradiation (for PV systems), and water flow and water head (for Micro-Hydro). Models for all three of these systems were developed in order to generate Maximum Power Point (MPP) curves. Similarly, a model for Permanent Magnet Synchronous Generators (PMSGs) has been developed in the d-q reference frame. A boost rectifier which enables active Power Factor Correction (PFC) and has a DC regulated output voltage is proposed before implementing a MPPT algorithm. The proposed boost rectifier works on the principle of Direct Power Control Space Vector Modulation (DPC-SVM) which is based on instantaneous active and reactive power control loops. In this technique, the switching states are determined according to the errors between commanded and estimated values of active and reactive powers. The PMSG and Wind Turbine behaviour are simulated at various wind speeds. Similarly, simulation of the proposed PFC boost rectifier is performed in matlab/simulink. The output of these models are observed for the variable wind speeds which identifies PFC and boosted constant DC output voltage is obtained. A buck converter that employs the MPPT algorithm is proposed and modeled. The model of a complete system that consists of a variable speed small wind turbine, PMSG, DPC-SVM boost rectifier, and buck converter implementing MPPT algorithm is developed. The proposed MPPT algorithm is based upon the principle of adjusting the duty ratio of the buck converter in order reach the MPP for different wind speeds (for small wind turbines) and different water flow rates (Micro-Hydro). Finally, a prototype DPC-SVM boost rectifier and buck converter was designed and built for a turbine with an output power ranging from 50 W-1 kW. Inductors for the boost rectifier and buck DC-DC converter were designed and built for these output power ranges. A microcontroller was programmed in order to generate three switching signals for the PFC boost rectifier and one switching signal for the MPPT buck converter. Three phase voltages and currents were sensed to determine active and reactive power. The voltage vectors were divided into 12 sectors and a switching algorithm based on the DPC-SVM boost rectifier model was implemented in order to minimize the errors between commanded and estimated values of active and reactive power. The system was designed for charging 48 V battery bank. The generator three phase voltage is boosted to a constant 80 V DC. Simulation results of the DPC-SVM based rectifier shows that the output power could be varied by varying the DC load maintaining UPF and constant boosted DC voltage. A buck DC-DC converter is proposed after the boost rectifier stage in order to charge the 48 V battery bank. Duty ratio of the buck converter is varied for varying the output power in order to reach the MPP. The controller prototype was designed and developed. A laboratory setup connecting 4 kW induction motor (behaving as a wind turbine) with 1kW PMSG was built. Speed-torque characteristic of the induction motor is initially determined. The torque out of the motor varies with the motor speed at various motor supply voltages. At a particular supply voltage, the motor torque reaches peak power at a certain turbine speed. Hence, the control algorithm is tested to reach this power point. Although the prototype of the entire system was built, complete results were not obtained due to various time constraints. Results from the boost rectifier showed that the appropriate switching were performed according to the digitized signals of the active and reactive power errors for different voltage sectors. Simulation results showed that for various wind speed, a constant DC voltage of 80 V DC is achieved along with UPF. MPPT control algorithm was tested for induction motor and PMSG combination. Results showed that the MPPT could be achieved by varying the buck converter duty ratio with UPF achieved at various wind speeds.

The biomedical applications of carbon nanomaterials are under intensive investigation for the development of next-generation therapeutics. Although much focus has been placed on carbon nanotubes (CNTs) and graphene, other carbon nanomaterials including carbon nanohorns (CNHs), nanodiamonds (NDs) and fullerenes have emerged as suitable candidates for biomedical applications. Among these multi-shell fullerenes, also known as carbon nano-onions (CNOs), are the less studied carbon nanomaterials in biomedicine. The unique properties of carbon nano-onions, such as high surface area-to-volume ratio, thermal conductivity, electrical conductance, mechanical stiffness and ease of chemical functionalization render them fascinating materials for diverse applications including drug-delivery, diagnostics, biological imaging and tissue engineering. Carbon nanomaterials are emerging as smart nanostructures for biomedicine due to the possibility to incorporate multiple functionalities and moieties internally or externally. They can be modified at a precise physicochemical level to optimize targeting in the complex in vivo environment and also engineered for fluorescence detection, magnetic resonance imaging and ablation of tumor cells. Herein, robust and versatile synthetic strategies for the modification of carbon nano-onions (CNOs) are reported. The development of novel CNO conjugates represent a promising platform for the realization of novel technology scaffold for molecular imaging, photodynamic therapy and molecular transporter of fully synthetic carbohydrate-based vaccines for immunotherapy due to the large specific surface area and unique optical and electrochemical properties of CNOs. Through the methodologies described, these smart nano-materials can envisage the realization of multi stimuli-responsive and dynamic architectures capable of changing their physicochemical behavior upon encountering specific microenvironmental signals becoming relevant for diagnosis, imaging and therapies of specific disease applications.

Gelatine, which is produced by collagen partial hydrolysis, has been largely used in the biomedical field for a wide variety of applications, which are ranging from drug delivery to wound healing. Its spread depends strongly on its biocompatibility: this natural polymer is indeed non-toxic, non-carcinogenic, non-immunogenic, enzymatically degradable and bioresorbable. In the biomedical field gelatine is mostly used as highly concentrated hydrogel (with a melting point above 43 °C - 45 °C) or cross-linked. This work investigated the use of uncross-linked gelatine hydrogels, with a melting temperature in the physiological range, for different biomedical applications. Firstly, it was studied the possibility to produce a solid hydrogel to use as easily removable wound dressing. Once applied to a wound, this patch keeps a moist environment in order to improve the regeneration, while releasing drugs or bioactive factors that it could be preloaded of. Moreover, it can be easily removed, without damages to the wound site and the newly formed tissue, by washing with warm sterile water (37 °C - 39 °C). Secondly, the gelatine material was investigated as substrate for the so-named cell sheet engineering. With our procedure cell sheets can be grown on the gelatine gel and, successively, they can be integrally transferred to a different surface, with gelatine being removed by melting at 37 °C, without any proteolytic enzyme. The gelatine sheet supporting cells, differently from the “Okano” cell sheet method, could be also directly implanted in-vivo without any need for removal, due to the gentle melting of the gelatine sheet after implantation. Thirdly, gelatine gels were used as depot to release pro-angiogenic factors in-vivo. Due to their ability to absorb aqueous solutions and release them while dissolving / degrading, gelatine gels were loaded with Amniotic Fluid Stem Cells Conditioned Medium and used to evaluate the effect of grow factors in a model of ischemic fasciocutaneous flap. Additionally, in order to evaluate the in-vivo degradation rate of gelatine gels loaded with Platelet Rich Plasma, a preliminary test was performed. The results of this test suggested the possibility to employ the gel films as antiadhesive membranes in surgery.

The repair or replacement of damaged or diseased hard tissue is a biomedical field that has been the subject of more and more interest in many areas of research and especially in the development of new biomaterials. The rise in the average age of the world population, increasing osteoporosis treatments and the spread of cancer and genetic bone diseases, has brought about the need to find solutions for patient care. To achieve this target/objective, biomaterials must simulate the body environment as much as possible and favour tissue repair by integrating them into the host site. Calcium phosphates are used as medical implants because they have a chemical composition similar to the mineral of human bones, i.e. apatite. For this reason they are biocompatible and they can interact in a bioactive way with bone tissue. In the present work a specific form of bone graft, in the form of calcium phosphate granules, has been developed by using the droplet extrusion technique. The granules were characterized chemically and physically, with specific attention to in vivo and in vitro analyses. The proposed method has allowed us to obtain spherical granules in very narrow micrometric size distribution (300-1200 μm) without the use of solvents or oils thus avoiding time consuming washing processes. Granules were produced with several controlled mineralogical compositions including: pure Hydroxyapatite (HA) and β-Tricalcium Phosphate (βTCP), mixtures of HA/βTCP and Hydroxyapatite/Tetracalcium phosphate (HA/TTCP), and compositions doped with zinc (for antibacterial purposes) and strontium (for anti-osteoporosis purposes). Of several interesting features, the produced granules show high interconnected microporosity (0.1-10 μm) and surface roughness, properties necessary for osteoconductivity. The solubility behavior of granules was studied and demonstrated that the morphology and microporosity are more important in dissolution processes than chemical or mineralogical composition. Products were tested in simulated body fluid (SBF), and among the different compositions, HA/TTCP has been found to be bioactive during in vitro studies. In fact an intense precipitation of a carbonated layer of apatite was observed, associated with the high dissolution of a TTCP phase. All pure granules were demonstrated to not be cytotoxic. Bone implantations in different animal models (rabbits and primates) showed good performance of granules in the repairing of bone. The granules stimulated the bone growth without any inflammatory reactions. In particular, HA/TTCP granules exhibited excellent biomechanical properties by increasing the stability of neo-formed bone. These preliminary investigations were sufficient to show that the developed granules can be used for bone repair or replacement. However, more studies, especially for doped products, such as in vitro cells experiments, have to be performed to assure the biocompatibility and the effective stimulation of bone growth. This work was performed in collaboration with Eurocoating S.p.A. (Trento, Italy), a company expert in biomedical coatings for prostheses and implants, and it is a part of “CaP project” co-sponsored by Provincia Autonoma di Trento (Italy).

Cuprite (Cu2O) and tenorite (CuO) have been extensively studied because of their potential use in several electronic applications, which include solar cells and gas sensors, just to mention the most appealing ones. Both materials are p-type semiconductors, the one with a wide bandgap (Cu2O, 2.0 eV-2.2 eV), the other with a much narrower one (CuO, 1.2 eV-1.8 eV), and both show interesting optical properties in the visible and near-visible range. This Thesis work is devoted to the synthesis, characterisation and application of nanostructured copper oxides in the field of renewable energies. Within this broad scope the Thesis focuses on: • production of defect-free nanocrystals (Cu2O & CuO) and investigation of the correlation between experimental parameters and resulting microstructure; • production of highly defective nanocrystalline Cu2O powders, with the estimation of the effect of milling on microstructure and phase transformations; • production of inks for photonic applications in photovoltaic cells. Reverse micelle microemulsions (a bottom-up approach) have been employed for the production of the defect-free nanocrystals. Models have been proposed for the nanocrystal formation and growth, validated by means of several techniques such as X-ray Diffraction (XRD), Scanning Electron Microscopy (SEM) and Transmission Electron Microscopy (TEM), UV-Visible and Fourier Transform InfraRed spectroscopy (UV-Vis and FTIR). The produced nanocrystals show good crystallinity with Cu2O and CuO exhibiting cuboidal and rod-like structures, respectively. The nanometric nature of the primary domains (20 nm – 4 nm) leads to quantum confinement phenomena highlighted by photoluminescence measurements. A top-down approach has been exploited to produce highly defective particles to be possibly employed in new-generation intermediate-band solar cells. A high-energy mill, suitably modified to work in controlled temperature and environment, allowed the production of highly defective copper oxides with little or no phase transformation and contamination from the mill. Finely dispersed powders with a high density of line defects (Ï â‰ˆ 4×10-16 m-2) were ultimately obtained. The effect of milling on the microstructure evolution was investigated using both traditional and synchrotron radiation XRD line profile analysis supported by High Resolution TEM and SEM. The synthesised powders were employed for the production of copper oxide inks for photonic applications. Those inks would allow solar cells to be directly printed on a substrate, with a dramatic reduction of production costs and the possibility of coating objects of any shape. Sprayed films usually need high consolidation temperatures: the proposed formulation, on the contrary, allows sintering of the ink-derived films at a relatively low temperature (below 600 °C), thus making possible the deposition on inexpensive substrates such as aluminium. Prototype solar cells based on the copper oxide inks have been fabricated using simple coating techniques. Results can be considered as a first step towards the production of fully recyclable solar cells, made of low-cost raw materials and realized by cost-effective deposition techniques.

The thesis project is focused on the synthesis and characterization of nanostructured bismuth ferrite, BiFeO3 (BFO), thin films with enhanced photoelectrocatalytic properties. Photoelectrocatalytic materials are semiconductors that are able to catalyze water splitting processes or other reactions under sunlight irradiation. They can, through the absorption of photons, create electron/hole pairs which can be exploited to carry out electrochemical reactions. BFO is a very promising perovskite-type material with an optical band gap that fits well with the sunlight irradiation in the visible region. Since most of the conventional photocatalyst like TiO2 is limited by a wide band gap and a UV light absorption, the BFO material is an interesting visible light driven photoactive material for solar energy conversion. The main disadvantages of such material are poor efficiency and high variability in the photoelectrocatalytic performance. BFO’s performance depends on structure, defects, phase, electronic properties, which are directly connected with the synthetic methodology. In this thesis a sol-gel synthesis has been optimized in order to prepare highly reproducible thin films, that could be directly applied to a device, with modified structure and improved photoelectrocatalytic performance. Moreover, in order to achieve sensitization in the Near Infrared Region where pure BFO is not active, a composite nanomaterial has been developed. Previously prepared nanoparticles with peculiar optical properties have been dispersed in a BFO matrix and the optical and structural characterization have been carried out to correlate the enhancement of photoelectrocatalytic properties with the modification caused by the nanoparticles doping.

Il ruolo cruciale che le interfacce solide rivestono nei problemi strutturali in numerosi campi dell'Ingegneria e ormai consolidato (Ingegneria Civile, Ingegneria Meccanica, Biomeccanica, ecc.), sicuramente esse rappresentano un argomento di grande interesse scientico. Al giorno d'oggi, la modellazione analitica e numerica delle interfacce strutturali sono un obiettivo sdante, sia a causa dei complessi fenomeni sici da tenere in conto (come l'adesione, il contatto non-conforme, la microfessurazione, l'attrito ed il contatto unilaterale), che della necessita di avere metodi numerici capaci di trattare simultaneamente l'esiguo spessore delle zone di interfaccia ed i salti nei campi sici, relativi al problema considerato. La seguente tesi di dottorato mira a sviluppare uno strumento analitico consistente e generale, che sia capace di superare le restrizioni tipiche delle strategie modellistiche esistenti, riguardanti le interfacce soft e hard caratterizzate da una microfessurazione evolvente. Si propone un nuovo approccio, denito Imperfect Interface Approach (IIA). Quest'ultimo, accoppia coerentemente argomenti della teoria asintotica e tecniche di omogeneizzazione per materiali microfessurati nel contesto della Non-Interacting Approxima- tion (NIA). Nel dettaglio, l'omogeneizzazione micromeccanica e impiegata per ottenere le proprieta elastiche eettive di un'interfase microfessurata situata tra due aderenti deformabili. Inoltre, utilizzando una procedura di sviluppo asintotico, vengono dedotte delle leggi di interfaccia nel problema limite, cioe per uno spessore di interfase che tende a zero. Nel contesto dell'elasticita lineare, l'IIA e impiegato con successo al ne di ottenere un insieme di modelli di interfacce imperfette, corrispondenti sia al caso di interfase tridimensionale inizialmente isotropo, che al caso di interfase bidimensionale inizialmente ortotropo. In particolare, nel caso bidimensionale si e dimostrato come si ottengano delle leggi di interfaccia rispettivamente soft e hard, in funzione dell'approccio d'omogeneizzazione adottato (in tensioni o in deformazioni). Generalizzando il metodo di sviluppo asintotico alla teoria elastica in deformazioni nite, si ottiene un modello d'interfaccia soft non-lineare. Come nuova applicazione, l'IIA e stato utilizzato al ne di formulare un modello di contatto non-conforme a molle equivalenti, che e stato confrontato con successo sia con le predizioni teoriche che con i dati sperimentali disponibili. Inne, sono state eseguite delle simulazioni numeriche, applicando alle strutture in muratura i modelli di interfaccia soft ottenuti nei casi lineare e non-lineare, confermando l'ecacia e la robustezza della formulazione proposta.
The crucial role of solid interfaces in structural problems in several engineering elds (e.g., Civil Engineering, Mechanical Engineering, Biomechanics, etc.) is well-established and they represent certainly a scientic topic of great interest. Nowadays, analytical and numerical modeling of structural interfaces are challenging tasks, due to the complex physical phenomena to take into account (such as adhesion, non-conforming contact, microcracking, friction, unilateral contact), as well as to the need of numerical methods suitable for treating small thickness of the interface zones and jumps in the physically relevant elds. Present PhD thesis aims to develop a consistent and general analytical tool able to overcome some modeling shortcomings of available modeling strategies accounting for soft and hard interfaces, and characterized by evolving microcracking. A novel approach, referred to as Imperfect Interface Ap- proach (IIA), is proposed. It consistently couples asymptotic arguments and homogenization techniques for microcracked media in the framework of the Non-Interacting Approximation (NIA). In detail, the micromechanical homogenization is exploited to nd the eective elastic properties of a microcracked interphase between deformable adherents. Additionally, by employing a matched asymptotic expansion method, the interface laws are deduced, in the limit of a vanishing interphase thickness. In the context of linear elasticity, the IIA is successfully employed to derive a set of imperfect interface, addressing both the case of an initially-isotropic three-dimensional interphase and of initially-orthotropic two-dimensional interphase. In particular, in two-dimensional case, stress/strain-based soft and hard interface laws are properly recovered as depending on the adopted homogenization approach. By generalizing the matched asymptotic expansion method to nite strains, a nonlinear soft interface model has been derived. As a new general application, the IIA is applied to formulate a spring-type model for non-conforming contact, which is successfully compared with theoretical predictions and available experimental data. Finally, numerical simulations applying the soft interface models obtained in both linear and nonlinear cases to masonry structures, are carried out, showing eectiveness and soundness of the proposed formulation.

Self-hardening aluminum alloys (Al-Zn-Si-Mg alloys) represent an innovative class of light aluminum alloys. They present high mechanical properties, which make them suitable for many applications in different industrial fields, especially in transport industry. The most important and relevant feature of the self-hardening alloys is related to their good performance, without the need of any heat treatment: they are subjected to a natural ageing phenomenon at room temperature after a storage period of about 7-10 days. The possibility to avoid the heat treatment represents an important benefit, contributing to considerably reduce both the production cost of some components and the amount of energy involved in the manufacturing process. Furthermore, without heat treatment the risk of component's deformation during the production is eliminated. The goal of this PhD Thesis was to find an alternative solution to the actually used T6 heat-treated A356 alloy for automotive component production. The feasibility of the development, of a knuckle suspension component, starting from the self hardening alloy was evaluated and investigated. In addition, some qualitative and semi-quantitative considerations was figured out from economical point of view. The use of the self-hardening aluminum alloy allows avoiding any heat treatment, consequently an important energy saving can be reached during the manufacturing, especially in terms of gas and electricity consumption, that are important features for the environment. A consistent part of this thesis was focalized on the study of the structural features and mechanical properties of the self-hardening aluminum alloys. Another part was dedicated to investigate their corrosion resistance. The effect of the Mg content and of the cooling rate, on the microstructure of three different self-hardening aluminum alloys, were investigated, aiming to define the optimal alloy composition for knuckle suspension component production.

Metal oxide chemical sensors based on nanomaterials are gaining popularity and finding extensive use in automotive industries, process control and environmental monitoring. ZnO, a semiconducting metal oxide has attracted great interest over the years for its sensitivity to a variety of gases. Nanostructured sensing materials, such as thin films, nanowires, tetrapods, nanoflackes offer an inherently high surface area, reducing operating temperatures and increasing sensitivity to low concentrations of analytes. In this thesis, ZnO nanostructures have been tested as chemical sensors and a detailed study on the effect of different process parameters such as grain size, roughness, surface-to-volume ratio, depletion layer, temperature, gas concentration and material properties on gas sensitivity is presented. Initially, ZnO nanodevices were prepared with a variety of techniques, such as RF sputtering, electrodeposition, hydrothermal growth, chemical vapour deposition, thermal evaporation and controlled oxidation. The structural characterization of the nanodevices has been done by a FEI QUANTA 3D dual beam SEM/FIB machine and by a Dimension 3100 Atomic Force Microscope (AFM) (Digital Instruments) in tapping mode. X-ray diffraction (XRD) spectra were recorded on an AXS D8 diffractometer (Bruker) with a Cu Kα X-ray tube. The gas sensor substrate based on alumina consisted of Pt grid of 50nm thickness and golden contacts of 200nm thickness creating an alumina patterned substrate. The sensor deposition area was coated with ZnO nanostructures to form the sensing material. Sensing measurements are performed in a closed steel chamber where air and tested gases have been inserted. ZnO based nanostructures’ response was measured in different concentrations of Ethanol, CO and NO2. Initially the role of grain size and roughness has been investigated in several thin film based nanodevices. Grain size is decreasing with increasing RF sputtering power and increasing by post-annealing treatment. Roughness instead is increasing with both the increasing of RF sputtering power and post-annealing treatment. High response was observed for those films with smaller grain size, while the roughness seems to influence very little the response of the sensor. For all thin films, the response is increasing with ii temperature and gas concentration. Recovery time and response time seem to follow a non-linear behavior with the above parameters. Extended studies have investigated the role of surface-to-volume ratio and depletion layer in the sensing performance. It has been observed that the increase of surface-to volume ratio has an important effect on the sensitivity, increasing, more than twice the response of such a device in respect to another that is based on a ZnO thin film. On the other hand, the dimensions of a nanostructure play the most crucial role in the depletion layer width in respect to the sensing properties. The diameter of a nanowire should be comparable with its depletion layer width. In this case the depletion layer has strong effect, which makes the sensor’s response depend also on it. The sensing properties of all fabricated structures have been compared to find the optimum sensor that could face the demands of automotive industries. All fabricated structures have been compared in different configurations to find out which one presents the best sensing performance. To that direction sensors based on thin film, tetrapods, nanowires, nanoflackes have been tested in same environmental conditions. Advanced nanostructures present better sensing properties. Sensing response of every advanced nanostructure presents more than double sensing response than every thin film-based nanostructure. Comparing the advanced nanostructures with each other, tetrapods based sensor has higher response and recovery time, while the sensitivity is slightly higher for the nanowires-based sensor. Theoretical studies have been performed by ab-initio simulations in NO2 environment. They have revealed that the sensing mechanism is driven almost exclusively by competitive adsorption between NO2 and atmospheric oxygen mediated by temperature change. The influence of the NO2 on the electronic properties of ZnO has been assessed and it is in accordance with the experiments. Our future work is the investigation of other materials for the development of sensing nanodevices targeting to develop more sensitive nanosensors in the same or lower cost. Additionally, the investigation of other growth techniques that could develop more complicated structures in low cost is another point of interest for the future.

The purpose of this research is to develop and improve the process of massive growth of carbon nanotubes (CNTs) via chemical vapor deposition (CVD). Beside the growth of CNTs and their potential applications, CNTs based polymer composites properties were also explored. The thesis may be divided into two major sections. In the first section a comprehensive introduction to carbon nanomaterials specifically CNTs (which includes the structure, types, growth mechanism and techniques, characterization techniques and properties) is described. Then the CVD growth procedure adopted in our lab to grow different carbon nanomaterials in particular Multiwall Carbon nanotubes (MWCNTs) under differential experimental conditions is discussed. We have grown upto 3mm thick MWCNTs carpet on Si substrate with MWCNTs diameter in the range 20nm-80nm. The individual length of MWCNTs is as long as few hundreds of micrometer. MWCNTs based structures were also grown on patterned surfaces. The patterning of the surfaces is performed by soft photolithography. These MWCNT structures have very interesting applications e.g. a). The vertical cylinders were use to produce SiC hollow cylinders, and b). CNT based fins grown on Si substrate were used to enhance the convective heat transfer properties. Several treatments (thermal annealing, acid treatment and plasma treatment) were also performed on MWCNTs in order to modify their characteristics. These procedures are useful for purification, functionalization and graphitization of MWCNTs. The second section about CNT based polymer composites starts with the brief introduction to polymer composites, processing techniques, major issues in mixing the CNTs in different polymers and finally the mixing tools used for better dispersion. The optical characterization of PDMS based MWCNTs composites films are studied. These films can have application in optical limiting devices. Furthermore, the transparency of these films is also used to calculate a unique parameter absorption cross section of a single MWCNT. The absorption cross section of individual MWCNTs having widely different aspect ratios scales with their volume. The approximation of absorption cross section per carbon atom is also in close agreement with that of graphite. The electrical conductivity phenomena in epoxy based carbon nanomaterials (CNMs) composites are also discussed. A total number of 16 types of different CNMs were used. Several conduction behaviors have been found e.g. from highly conductive CNTs which showed linear Ohmic curve, to non-linear diode-like trend to completely insulating one. The best performances have been reached by the shortest and thinner MWCNTs (both as grown and slightly functionalized with COOH groups), which can underline that small fillers can be better dispersed inside the composite and create a better conductive net within the matrix. We have also applied physical models such as the percolation theory and the fluctuation mediated tunnelling theory to the most conductive nanocomposites, with poor agreement between experimental data and theoretical prediction. Finally, we applied a recently revised model based on tunnelling-percolation theory and obtained a good fit between experimental and theoretical results.

L'Open Data, letteralmente “dati aperti”, è la corrente di pensiero (e il relativo “movimento”) che cerca di rispondere all'esigenza di poter disporre di dati legalmente “aperti”, ovvero liberamente re-usabili da parte del fruitore, per qualsiasi scopo. L’obiettivo dell’Open Data può essere raggiunto per legge, come negli USA dove l’informazione generata dal settore pubblico federale è in pubblico dominio, oppure per scelta dei detentori dei diritti, tramite opportune licenze. Per motivare la necessità di avere dei dati in formato aperto, possiamo usare una comparazione del tipo: l'Open Data sta al Linked Data, come la rete Internet sta al Web. L'Open Data, quindi, è l’infrastruttura (o la “piattaforma”) di cui il Linked Data ha bisogno per poter creare la rete di inferenze tra i vari dati sparsi nel Web. Il Linked Data, in altre parole, è una tecnologia ormai abbastanza matura e con grandi potenzialità, ma ha bisogno di grandi masse di dati tra loro collegati, ossia “linkati”, per diventare concretamente utile. Questo, in parte, è già stato ottenuto ed è in corso di miglioramento, grazie a progetti come DBpedia o FreeBase. In parallelo ai contributi delle community online, un altro tassello importante – una sorta di “bulk upload” molto prezioso – potrebbe essere dato dalla disponibilità di grosse masse di dati pubblici, idealmente anche già linkati dalle istituzioni stesse o comunque messi a disposizione in modo strutturato – che aiutino a raggiungere una “massa” di Linked Data. A partire dal substrato, rappresentato dalla disponibilità di fatto dei dati e dalla loro piena riutilizzabilità (in modo legale), il Linked Data può offrire una potente rappresentazione degli stessi, in termini di relazioni (collegamenti): in questo senso, Linked Data ed Open Data convergono e raggiungono la loro piena realizzazione nell’approccio Linked Open Data. L’obiettivo di questa tesi è quello di approfondire ed esporre le basi sul funzionamento dei Linked Open Data e gli ambiti in cui vengono utilizzati.

Ces travaux de thèse ont eu deux objectifs: i) le développent de systèmes nanofluidique en utilisant une méthode non-lithographique, peu chère et facilement transposable à l'échelle industrielle ii) la compréhension des phénomènes nanofluidiques au travers des études expérimentales et de modélisation. Des couches minces mesoporeuses, en particulier des structures planaires avec des nanopiliers, ont été utilisé pour des études sur l'infiltration capillaire des liquides dans espaces confiné au niveau nanométrique. En plus des premiers tests pour des applications plus complexes comme des séparations et réactions nanoconfiné. Des structures mesoporeuses non-organisés ont aussi été étudiées pour déterminer la relation entre la nanostructure et la vitesse de remplissage capillaire. A été aussi démontré que pour des porosités avec des forts rétrécissements le remplissage capillaire se produit par l'intermédiaire d'une phase vapeur. Les échantillons ont été préparés par dip-coating. Une méthode de préparation basé sur une substitution de la plus grande parte de la solution à déposer par un fluide inerte a été développé. La méthode permet de réduire fortement le cout de procédé et, par conséquence, de faire des dépôts sur plus grande surface. Un effort dans la modélisation des phénomènes nanofluidiques a aussi été fait pendant cette thèse. Une méthode de simulation qui permet de décrire adéquatement les interactions hydrodynamiques dans un système nano a été utilisée pour simuler un flux électro-osmotique. La méthode, Stochastic Rotational Dynamics, a été valide par confrontation avec des résultats connus et l'influence des certains paramètres de simulation évaluée dans le détail
This thesis had a dual purpose: i) the development of nanofluidic devices through not lithographic, cheap and scalable bottom-up approach ii) the understanding of nanofluidic phenomena both through experiments and simulations. Mesoporous thin films, in particular Pillared Planar Nanochannels (PPNs), were prepared and utilized to study the capillary infiltration of liquids in nanostructures and have been tested for future nanofluidic applications like separations and nanoconfined reactions. Non organized mesoporous films have also been studied to determine the relationship between nanostructure characteristics and infiltration speed. It has been also demonstrated that in the case of porosities with reduced bottle-necks capillary penetration is performed through a vapor mediated mechanism The samples were prepared by dip-coating. A novel method of preparation based on the substitution of a large part of the deposing solution in dip-coating with an inert fluid has been developed in order to strongly reduce the fabrication costs and allow the preparation of larger samples. Moreover advancement in control of the dip-coating technique in “acceleration-mode” to produce thickness gradients has been developed and some potential application linked to fluidics shown. Finally a part of the effort of this thesis has been placed in the modeling of the electro-osmotic phenomenon in nanostructures through a rather novel simulation method, Stochastic Rotational Dynamics, which takes into account the hydrodynamics and the other interactions inside a nanofluidic system. Validations of the method and further investigations in particular nanofluidic conditions have been performed

In this work, new tools in atmospheric pollutant sampling and analysis were applied in order to go deeper in source apportionment study. The project was developed mainly by the study of atmospheric emission sources in a suburban area influenced by a municipal solid waste incinerator (MSWI), a medium-sized coastal tourist town and a motorway. Two main research lines were followed. For what concerns the first line, the potentiality of the use of PM samplers coupled with a wind select sensor was assessed. Results showed that they may be a valid support in source apportionment studies. However, meteorological and territorial conditions could strongly affect the results. Moreover, new markers were investigated, particularly focusing on the processes of biomass burning. OC revealed a good biomass combustion process indicator, as well as all determined organic compounds. Among metals, lead and aluminium are well related to the biomass combustion. Surprisingly PM was not enriched of potassium during bonfire event. The second research line consists on the application of Positive Matrix factorization (PMF), a new statistical tool in data analysis. This new technique was applied to datasets which refer to different time resolution data. PMF application to atmospheric deposition fluxes identified six main sources affecting the area. The incinerator’s relative contribution seemed to be negligible. PMF analysis was then applied to PM2.5 collected with samplers coupled with a wind select sensor. The higher number of determined environmental indicators allowed to obtain more detailed results on the sources affecting the area. Vehicular traffic revealed the source of greatest concern for the study area. Also in this case, incinerator’s relative contribution seemed to be negligible. Finally, the application of PMF analysis to hourly aerosol data demonstrated that the higher the temporal resolution of the data was, the more the source profiles were close to the real one.

In this work, new tools in atmospheric pollutant sampling and analysis were applied in order to go deeper in source apportionment study. The project was developed mainly by the study of atmospheric emission sources in a suburban area influenced by a municipal solid waste incinerator (MSWI), a medium-sized coastal tourist town and a motorway. Two main research lines were followed. For what concerns the first line, the potentiality of the use of PM samplers coupled with a wind select sensor was assessed. Results showed that they may be a valid support in source apportionment studies. However, meteorological and territorial conditions could strongly affect the results. Moreover, new markers were investigated, particularly focusing on the processes of biomass burning. OC revealed a good biomass combustion process indicator, as well as all determined organic compounds. Among metals, lead and aluminium are well related to the biomass combustion. Surprisingly PM was not enriched of potassium during bonfire event. The second research line consists on the application of Positive Matrix factorization (PMF), a new statistical tool in data analysis. This new technique was applied to datasets which refer to different time resolution data. PMF application to atmospheric deposition fluxes identified six main sources affecting the area. The incinerator’s relative contribution seemed to be negligible. PMF analysis was then applied to PM2.5 collected with samplers coupled with a wind select sensor. The higher number of determined environmental indicators allowed to obtain more detailed results on the sources affecting the area. Vehicular traffic revealed the source of greatest concern for the study area. Also in this case, incinerator’s relative contribution seemed to be negligible. Finally, the application of PMF analysis to hourly aerosol data demonstrated that the higher the temporal resolution of the data was, the more the source profiles were close to the real one.

The work of this doctoral thesis can be mainly divided in three parts. In the first part, the synthesis and characterization of different types of inorganic nanoparticles (NP) is described. The full protocol to prepare NP-GS, NP-Si)GS, and NP-Si)Au was found in literature. Stöber method-synthesized NP-Si were used as a platform to create NP-Si)GS, and NP-Si)Au. A novel method to conjugate antitumor drugs (s-Azl 6 and s-Azl 38) to Au-NP was also developed. Studies on Azl 6 and Azl 38 showed that they are highly hydrophobic, but when conjugated with Au-NPs, in the presence of an amphiphilic molecule (C), the complex (DNPC) passed through water. NP-Si, NP-GS, NP-Si)GS, and NP-Si)Au were characterized with electron microscopy, x-ray diffraction (EDS), and DLS. Although synthesis appeared to be easy to perform, results showed that NP-Si)Au did not form, while NP-GS and NP-Si)GS were obtained. NP-GS have a small diameter (2-3 nm on average), while for NP-Si and NP-Si)GS a diameter of 178-205,52 nm, and 164,80-178,66 nm respectively was calculated. TEM and SEM microscopy also indicated that NP-Si)Au corroded, and the gold envelope, that was supposed to coat the whole particule, was observed detached from the silica NP and in the form of small spheres. The reason why the synthesis of NP-Si)Au did not succeed, maybe relies on the particular type of Si-NP used. Further studies will deepen this aspect. The culture of three different types of human cell phenotypes is accurately described in the second part. For our experiments, we decided to cultivate human melanocytes, a human melanoma cell line, and human keratinocytes. Melanocytes appeared characterized by a dendritic-like morphology, and they showed a very slow growth rate. On the contrary, we observed that their corresponding tumor cells (melanoma) grew quickly and, although they were sold as adherent cells, floating living cells were also found in cultures. Finally, in human keratinocytes two morphotypes were observed. The first (the most diffused) had the typical “cobblestone shape” of keratinocytes, while the second appeared bigger than the first, flattened, and with a jagged contour. Finally, in the third part of this work, the toxicity of inorganic NP (i.e., NP-Si, NP-GS, and NP-Si)GS), DNPC, inorganic rhodaminated NP conjugated with heparin, and lipid NP containing paclitaxel (NC-Pacli), was tested on the cell phenotypes mentioned above. CellTiter Blue reagent was selected to quantify cell viability, and it was chosen among other dyes and assays for its non-toxicity and easiness of use. It was shown that among inorganic NP, only Si-NP have toxic effect, especially on healthy cells. NC-Pacli, on the contrary, caused the decrease of cell viability on healthy and tumor cells.

Background scientifico: Alicyclobacillus spp. comprende microrganismi sporigeni e termoacidofili isolati in diversi habitat (suolo, bevande acide, frutti e impianti di produzione di succhi di frutta). Il genere include diverse specie e sottospecie, ma A. acidoterrestris è considerato l’alterante per eccellenza dei succhi di frutta e delle bevande acide. (i) Considerando la rapida capacità di adattamento ad ambienti diversi da parte di molteplici ceppi di A. acidoterrestris isolati da suolo, questo progetto di tesi ha studiato l’effetto di alcuni fattori, non ultima la disponibilità di nutrienti e l’habitat, sulla filogenesi del genere. (ii) Differenti approcci fisici, chimici e combinati sono stati testati su diversi ceppi di A. acidoterrestris per studiarne la resistenza e l’eventuale presenza di danno sub-letale. (iii) L'efficacia in vitro di alcuni trattamenti è stata valutata in condizioni reali. Scopo del lavoro: (i) Selezione e caratterizzazione di ceppi “wild” di A. acidoterrestris. (ii) Studio dei cambiamenti strutturali e funzionali in A. acidoterrestris e Bacillus spp. (usato come riferimento) in seguito all' applicazione di diversi trattamenti invasivi di controllo. (iii) Validazione in un sistema reale (succo di mela limpido) per evidenziare l’eventuale presenza di danno sub-letale in un sistema complesso. Pianificazione della ricerca: (i) 25 ceppi autoctoni di A. acidoterrestris sono stati isolati da suolo (23 ceppi) e da succo di pera alterato (CB-1 e CB-2), successivamente identificati e sottoposti ad analisi genotipica e fenotipica. (ii) 4 ceppi di A. acidoterrestris (ceppo di collezione, 2 ceppi isolati da suolo e un ceppo isolato da succo di pera alterato) e 2 specie del genere Bacillus sono stati sottoposti a diversi trattamenti chimici, fisici e combinati per valutarne la suscettibilità e la presenza di danno sub-letale. In relazione alla presenza di danno sub-letale, è stato effettuato uno studio atto a spiegare l’entità del danno. (iii) La presenza di danno sub-letale valutata attraverso mezzi di laboratorio è stata confermata in un sistema reale. Materiali e metodi: (i) L’analisi genotipica dei ceppi è stata realizzata attraverso l’amplificazione del 16S rRNA e mediante RAPD PCR (Random-Amplified-polimorfi-DNA); l’analisi fenotipica mediante mezzi specifici di laboratorio. (ii) La caratterizzazione del danno sub-letale è stata effettuata attraverso spettrofotometria e metodo di Bradford. (iii) Per le prove in vivo è stato utilizzato succo di mela limpido. Risultati: (i) I dati relativi alla caratterizzazione genotipica e fenotipica dei microrganismi isolati dal suolo suggeriscono una loro suddivisione in tre blocchi, evidenziando un possibile adattamento dei ceppi dal terreno verso altri ambienti. Numerosi ceppi diversi da un punto di vista genotipico, inoltre, hanno mostrato i medesimi tratti fenotipici, suggerendo la possibilità che A. acidoterrestris esista come “genomovar”. I risultati relativi al ceppo CB-1 hanno mostrato un profilo fenotipico distante dagli altri alicyclobacilli e con caratteristiche simili solo all’ altro isolato da succo (CB-2). (ii) L’effetto dei diversi trattamenti sui 4 ceppi di A. acidoterrestris è risultato ceppo-dipendente e probabilmente correlato alla fonte di isolamento primaria dei microrganismi; tuttavia, la presenza di danno sub-letale in relazione al rilascio di acidi nucleici, proteine e DPA, ha sottolineato delle lesioni a carico del cortex e della membrana esterna rivelando la perdita delle proprietà barriera delle spore. (iii) La sperimentazione condotta in succo di mela ha confermato i risultati ottenuti con mezzi di laboratorio. Significato e importanza della ricerca: A. acidoterrestris è sempre stato considerato un microrganismo “target” importante per il controllo della qualità di bevande acide e succhi di frutta. Considerando che i ceppi nativi del suolo spesso contaminano i frutti e sono in grado di crescere in condizioni di elevata acidità e sopravvivere a trattamenti di pastorizzazione, diventa importante comprendere se e come le specie del suolo potrebbero evolvere dalle loro nicchie ecologiche in comunità microbica adattate a nuovi ambienti quali i succhi di frutta. La presente tesi di dottorato contribuisce a chiarire questi aspetti attraverso un lavoro di isolamento e caratterizzazione di diversi ceppi “wild” di A. acidoterrestris, e fornisce le informazioni necessarie atte a chiarire il trend evolutivo da parte di alcuni ceppi. Inoltre, sono stati studiati i cambiamenti a carico di A. acidoterrestris dopo l'applicazione di stress sub-letali. Infine, la novità di questa attività di ricerca è stata la valutazione del danno sub-letale in spore di A. acidoterrestris in condizioni reali. Trend futuri: In futuro la ricerca potrebbe focalizzarsi su un “riarrangiamento” della nomenclatura dei ceppi di collezione, considerando l'atteggiamento evolutivo di alcuni ceppi di A. acidoterrestris, e la diversa suscettibilità ai diversi trattamenti applicati da parte del “type strain” in relazione agli altri ceppi testati.
Scientific background: Alicyclobacillus spp. includes spore-forming and thermo-acidophilic microorganisms, usually recovered from soil, acidic drinks, orchards and equipment from juice producers. The genus includes different species and sub-species, but A. acidoterrestris is generally regarded as the most important spoiler for acidic drinks and juices. (i) The investigation of microbial community evolution was performed, since soil species could acquire specific phenotypic traits in relation to available nutrients. (ii) A variety of physical and chemical approaches to control A. acidoterrestris were proposed, and the study of sub-lethal injury related to extend of damage was examined. (iii) In vitro stress treatments were tested in vivo. Open questions: (i) Few data are available on the genotyping and phenotyping traits of A. acidoterrestris; (ii) Few data are available on the effect of innovative approaches to control A. acidoterrestris; and no data are available on the sub-lethal injury in A. acidoterrestris after invasive treatments; (iii) Few data are available on the control of A. acidoterrestris in complex conditions. Aims: (i) Selection and characterization of wild strains of A. acidoterrestris as a contribution to species characterization, (ii) studying the structural and functional changes that may affect alicyclobacilli and Bacillus spp. (used as reference) after the application of several sub-lethal physical or chemical treatments, and (iii) validation in a food to assess if an injury could occur also in a complex system. Planning of the research: In the first part, 25 wild strains of A. acidoterrestris from soil (23 strains) and spoiled pear juice (CB-1 and CB-2) were isolated, identified, genotyped and phenotyped. In the second part, 4 strains of A. acidoterrestris (the type strain, 2 wild strains isolated from soil and a wild strain isolated from spoiled pear juice) and 2 species of Bacillus spp. were studied under in vitro conditions after the application of chemical, physical and combined treatments to assess their susceptibility and the presence of sub-lethal injury. The characterization of damage was also performed. Finally, in the last step the presence of sub-lethal injury in vivo was investigated. Materials and Methods: (i) Genotypic traits were performed through examining of 16S rRNA and RAPD PCR (Random-Amplified-Polymophic-DNA). Phenotypical traits were assessed on the opportune laboratory media. (ii) Injury characterization was evaluated by Leakage of UV-absorbing substances and BSA protein assay. (iii) For in vivo assay, clarified apple juice was used. Results: (i) Data of soil-borne strains pinpointed that they could be divided into three blocks, represented by soil strains and by strains moving from soil to other niches. In this context, phenotyping and genotyping did not group the strains in the same way and many strains phylogenetically different showed the same phenotypic trend, thus suggesting that A. acidoterrestris could exist as a genomovar. In addition, the strain CB-1 was distant from other alicyclobacilli, although it possessed the same traits than the other isolate from juice (CB-2); therefore, it is probably a fast-clock organism or the beginning on an alternative pathway in alicyclobacilli evolution. (ii) Alternative approaches applied to control 4 strains of A. acidoterrestris determined a strain-dependent effect probably related to the isolation source; however, the presence of sub-lethal injury related to released nucleic acids, proteins and DPA by spores pointed out the damage on coat and cortex with loss of barrier properties. (iii) The study performed in apple juice confirmed the results obtained in lab media. Significance and Impact of PhD research: From the earliest times, A. acidotererstris was regarded as an important target in the quality control of acidic beverages. Since soil borne species often contaminate fruit juices and do not need strict extreme requirements of acidity and high temperature for survival, it is a great concern to investigate whether and how soil species could evolve from their ecological niches in microbial community to new environments as fruit juices. The present PhD thesis contributed to species characterization through selection and characterization of wild strains of A. acidoterrestris, and provided essential knowledge to validate the genotyping and phenotyping evolution of some strains of A. acidoterrestris. Moreover, this PhD project was the first attempt to investigate the changes that may affect alicyclobacilli after sub-lethal stress application; the release of proteins, nucleic acids and DPA was strictly strain dependent. Finally, the novelty of this PhD thesis was the study of sub-lethal injury on A. acidoterrestris spores in vivo. Future trends: A future perspective could be a focus on a reassessing of strains nomenclature, considering the evolution of some strains of Alicyclobacillus genus, and the different behavior of the type strain compared to the other targets tested.

Since the discovery of vulcanization, rubbers have invaded our life and nowadays occupie a significant place in the industrial world. In fact, in most applications there are no alternative materials to them. Despite what it could be thought, a rubbery object is a very complex system. In fact, it is generally based on only one or more rubbers and on several other additives, such as reinforcing fillers, plasticizers, antidegradants, vulcanizing agents. Different production phases are required to realized a rubbery product. The first is the rubber compounding with the additives, which occurs at a defined temperature for a fixed time. The dispersion degree achieved by the fillers in the elastomeric matrix and consequently the final product properties are strictly dependent on this first step of production. After the mixing, the forming operations follow: the compound will retain the shape imposed. Finally, vulcanization process provides the material its ‘elastic’ recovery behaviour. The final properties of a rubber product depend mainly on the type of rubber chosen, however they can be further manipulated by varying the additives used and their concentrations, and the processing steps. The special character of rubber, being a multicomponent system, and the complexity of the production phases delayed the study and the development of rubber nanocomposites, in respect to the polymeric ones. However, in the ten past years, the reports published that deal with rubber nanocomposites have been raise. The ongoing R&D interest is mostly due to the significant physico-mechanical properties improvement which is observed when the nanoclays are added to a rubber matrix. This enhancement depends on the nanometric-scale dispersion that the nanoclays can achieve in the compound; contrary to the conventional fillers, such as carbon black and silica, which carry out a micrometric-scale dispersion. Nowadays, the nanoclays are the most studied nano-sized fillers because there are easily available in nature and cheap. Several research works have demonstrated that the addition of even low amounts of layered nanofillers (< 10 wt.%) improves the mechanical properties, decreases gas permeability and swelling in solvents, increases thermal endurance and flame resistance. This PhD activity was financed by the company “IVG Colbachini” placed in Cervarese Santa Croce, Padova. The company, for over 40 years, has been involved in the production of industrial rubber hoses to convey powders, granular, liquid or gas materials. The “IVG Colbachini” products are used in different sectors, such as food, chemical, agricultural, construction, rail, naval and steel industries. The thesis work was aimed at the study and the optimization of rubber compounds produced in “IVG Colbachini”. This thesis consists of 6 chapters and subsequently the main topics dealt with in each chapter will be concisely summarized. Chapter 1 highlights the significant differences between a conventional composite and a nanocomposite, giving also a classification of this latter class of materials. In addition, it explains which filler features are the most important to obtain a nanocomposite and how each of these can influence the final product properties. In Chapter 2 nanoclays and rubber nanocomposites loaded with layered fillers are introduced. Particularly, the chemical structure of these latter and the organo-modification importance are described. In addition there is a summary of the rubber/clay nanocomposite synthesis methods and their characteristic properties present in literature, such as mechanical performance, barrier effect and flame resistance. Chapter 3 explains step by step the art of rubber compounding. In particular, the concept of recipe and how it is indicated are introduced. Types, features and functions of recipe diverse ingredients are specified. In addition, the different processing steps are described, starting from the component mixing, proceeding with the forming, until to the vulcanizing. Finally, some applications of rubber products are summarized. Chapter 4 deals with materials used for the formulations subject of this thesis, experimental procedures and characterization techniques applied. Chapter 5 is devoted to tests carried out on an ethylene vinyl acetate based rubber compound, with the aim to improve its flame retardant properties. The obtained results are indicated and some whose interpretations are presented. Chapter 6 surveys the mechanical performances of a natural rubber/polybutadiene blend. Particularly, the experimental data obtained from the rubber compounds filled with conventional fillers, such as silica and carbon black, are compared with the ones found for the rubber compounds loaded with innovative fillers, like the nanoclays.
Dopo la scoperta del processo di vulcanizzazione, le gomme hanno invaso la nostra vita e attualmente occupano un posto significativo nel mondo industriale tanto che per molte applicazioni non ci sono materiali alternativi ad esse. A differenza di quanto si potrebbe pensare, un oggetto di gomma è una sistema piuttosto complesso. Infatti, esso è in genere costituito da uno o più elastomeri e da molti altri additivi, quali ad esempio cariche rinforzanti, plastificanti, antidegradanti, agenti vulcanizzanti, etc. La realizzazione di un prodotto finito in gomma prevede una serie di operazioni. La prima di queste prevede la miscelazione dell’elastomero/i con diversi additivi ad una specifica temperatura per un tempo prefissato. Tale operazione è significativa nel determinare il grado di dispersione degli additivi nella matrice, influenzando quindi le proprietà del prodotto finale. Successivamente si verifica l’operazione di formatura durante la quale viene data una forma definita alla mescola. Infine con il processo di vulcanizzazione l’oggetto acquisisce la caratteristica proprietà di ritorno elastico, tipica delle gomma. Le proprietà finali di un prodotto di gomma dipendono innanzitutto dall’elastomero di partenza, tuttavia possono essere ampiamente manipolate variando la tipologia e la concentrazione degli additivi aggiunti e le fasi di lavorazione. Il fatto di essere un sistema multicomponente e la complessità delle fasi di produzione sono i motivi principali che hanno ritardato lo studio e lo sviluppo dei nanocompositi a base elastomera rispetto a quelli polimerici. Tuttavia, negli ultimi dieci anni il numero dei lavori scientifici sui nanocompositi elastomerici è ampiamente aumentato. Il continuo interesse deriva dal notevole miglioramento delle proprietà fisico-meccaniche che si osserva quando additivi nanodimensionali sono introdotti in una matrice elastomerica. Il miglioramento ottenuto dipende dalla dispersione a livello nanometrico che tali riempitivi possono raggiungere, contrariamente ai più comuni silice e nero fumo che si disperdono su scala micrometrica. Ad oggi, le nanocariche maggiormente studiate per la loro disponibilità in natura e il basso costo sono le nanoargille. Numerosi studi hanno dimostrato che l’aggiunta di piccole quantità di silicati a strati (< 10 wt.%) migliora le proprietà meccaniche, riduce la permeabilità ai gas e il rigonfiamento in solventi, aumenta la stabilità termica e la resistenza alla fiamma. La borsa di studio di questo dottorato è stata finanziata dalla ditta “IVG Colbachini” di Cervarese Santa Croce, Padova. L’azienda, da più di 40 anni, realizza tubi industriali in gomma per la conduzione di polveri, granuli, gas, liquidi. I prodotti di “IVG Colbachini” trovano applicazione nei settori più diversi, tra i quali l’industria chimica e agro-alimentare, l’edilizia, la cantieristica navale e da diporto, le apparecchiature ferroviarie, le lavorazioni dei metalli. Il lavoro di tesi svolto è stato dedicato allo studio e all’ottimizzazione di mescole elastomeriche prodotte in “IVG Colbachini”. Questa tesi consta di 6 capitoli e di seguito saranno riassunti brevemente gli argomenti principali trattati in ciascun capitolo. Il Capitolo 1 evidenzia le differenze sostanziali tra composito convenzionale e nanocomposito, fornendo anche una classificazione di quest’ultima categoria di materiali. Inoltre spiega quali caratteristiche di un filler sono di fondamentale importanza per la realizzazione di un nanocomposito e come ciascuna di esse influenzi le proprietà del materiale finale. Nel Capitolo 2 è contenuta una presentazione delle nanoargille e dei nanocompositi elastomerica additivati con filler a strati. In particolare si descrivono la struttura chimica di quest’ultimi e l’importanza del modificante organico. A questo si aggiunge un quadro dei metodi di sintesi di questi nanocompositi e delle loro proprietà tipiche riportate in letteratura, quali le prestazioni meccaniche, l’effetto barriera ai gas e la resistenza alla fiamma. Il Capitolo 3 illustra passo passo l’arte della lavorazione della gomma. In particolare si introduce il concetto di “ricetta elastomerica” e come viene in genere espressa. Vengono specificate le tipologie, le caratteristiche e le funzioni dei diversi componenti di una “ricetta”. Inoltre si descrivono le varie fasi di produzione di un oggetto in gomma, partendo dalla miscelazione degli ingredienti, passando per la formatura, arrivando fino al processo di vulcanizzazione. In questo capitolo vengono infine riportate alcune possibili applicazioni di prodotti in gomma. Nel Capitolo 4 si introducono i materiali impiegati per la produzione delle formulazioni, oggetto di questo lavoro di tesi, le procedure sperimentali e le tecniche di caratterizzazione utilizzate. Il Capitolo 5 illustra le prove condotte su una mescola elastomerica a base di etilene vinil acetato, con lo scopo di migliorarne le proprietà di resistenza alla fiamma. Vengono quindi riportati i risultati ottenuti e proposte alcune interpretazioni di essi. Nel Capitolo 6 ci si è concentrati sullo studio delle proprietà meccaniche di un blend costituito da gomma naturale e polibutadiene. In particolare, i dati sperimentali ottenuti da mescole contenenti riempitivi tradizionali, come silice e nero fumo, sono stati confrontati con quelli ricavati da compound con filler innovativi, quali le nanoargille.

This dissertation will be focused on the characterization of an atmospheric pressure plasma jet source with an application oriented diagnostic approach and the description of processes supported by this plasma source. The plasma source investigated is a single electrode plasma jet. Schlieren images, optical emission spectra, temperature and heat flux profiles are analyzed to deeply investigate the fluid dynamic, the chemical composition and the thermal output of the plasma generated with a nanosecond-pulsed high voltage generator. The maximum temperature measured is about 45 °C and values close to the room temperature are reached 10 mm down the source outlet, ensuring the possibility to use the plasma jet for the treatment of thermosensitive materials, such as, for example, biological substrate or polymers. Electrospinning of polymeric solution allows the production of nanofibrous non-woven mats and the plasma pre-treatment of the solutions leads to the realization of defect free nanofibers. The use of the plasma jet allows the electrospinnability of a non-spinnable poly(L-lactic acid) (PLLA) solution, suitable for the production of biological scaffold for the wound dressing.

This dissertation will be focused on the characterization of an atmospheric pressure plasma jet source with an application oriented diagnostic approach and the description of processes supported by this plasma source. The plasma source investigated is a single electrode plasma jet. Schlieren images, optical emission spectra, temperature and heat flux profiles are analyzed to deeply investigate the fluid dynamic, the chemical composition and the thermal output of the plasma generated with a nanosecond-pulsed high voltage generator. The maximum temperature measured is about 45 °C and values close to the room temperature are reached 10 mm down the source outlet, ensuring the possibility to use the plasma jet for the treatment of thermosensitive materials, such as, for example, biological substrate or polymers. Electrospinning of polymeric solution allows the production of nanofibrous non-woven mats and the plasma pre-treatment of the solutions leads to the realization of defect free nanofibers. The use of the plasma jet allows the electrospinnability of a non-spinnable poly(L-lactic acid) (PLLA) solution, suitable for the production of biological scaffold for the wound dressing.

The PhD thesis describes the experimental activity concerning the elaboration and characterization of ceramic-polymer nanocomposites for dielectric and piezoelectric applications. In particular, barium titanate based 0-3 composites were processed by means of the photo-polymerization process and the solvent casting technique.

2003/2004
Nell'ambito della ricerca sui trasporti si è assistito allo sviluppo di una serie di modelli di scelta discreta, modale in particolare, accomunati dali' assunzione di funzioni di utilità lineari negli attributi e per questo denominati anche modelli compensativi; la rappresentazione delle strategie decisionali dei soggetti avviene quasi unicamente mediante modelli basati sull'ipotesi secondo la quale il decisore opera un "trade-off' tra gli attributi che caratterizzano le alternative disponibili, ottenendo una valutazione complessiva della convenienza di ciascuna di queste. Molteplici sono tuttavia le osservazioni di comportamenti reali almeno parzialmente non compensativi. I modelli compensativi presentano alcuni aspetti criticabili sia da un punto di vista teorico che pratico; innanzitutto si ipotizza che il decisore valuti contemporaneamente tutte le alternative su tutti gli attributi, selezionando l'alternativa con il maggior valore di utilità complessiva. Tale ipotesi porta, in diverse situazioni di scelta, a sopravvalutare le capacità dell'essere umano di recepire ed analizzare le informazioni. In aggiunta a ciò i modelli compensativi, in generale, producono variazioni nella distribuzione delle scelte anche per variazioni quasi non percettibili dei valori degli attributi, questo compromette in certi casi la loro efficacia predittiva; in realtà, come confermano diverse ricerche in campo psicologico, la percezione umana degli attributi posseduti dalle alternative disponibili è comunque caratterizzata da valori soglia superati i quali effettivamente può verificarsi un cambiamento nel comportamento ("just noticeable differences "). Alla luce di tali considerazioni la presente ricerca si è proposta, dopo una breve descrizione delle più conosciute regole decisionali alternative a quella compensativa, di identificare una metodologia capace di tenere in considerazione e quindi di descrivere efficacemente l'eterogeneità dei processi decisionali umani. Tale tentativo si è tradotto in termini pratici nella formulazione e sviluppo di un modello capace di considerare tale eterogeneità, cercando comunque di mantenere un'accettabile operatività del medesimo. In base alle ipotesi comportamentali sulle quali si fonda il modello (denominato modello Sequenziale a Soglie di Accettabilità), il generico decisore considera gli attributi secondo uno specifico ordine di importanza ed elitnina le alternative che non soddisfano, ad un dato passo del processo sequenziale, la soglia di accettabilità relativa all'attributo considerato (il campo di scelta viene in tal modo ristretto). Se alla fine del processo più alternative vengono conservate, la probabilità di scelta di ciascuna di esse viene calcolata compensando gli effetti degli attributi componenti la sequenza di valutazione. In altri termini si può affermare che la probabilità di scelta delle singole alternative disponibili, al termine del processo di valutazione sequenziale, è proporzionale alla preferenza complessiva ad esse accordata dal soggetto decisore; esiste tuttavia una sensibilità del decisore nei confronti dei diversi attributi che caratterizzano le alternative, la quale è esprimibile mediante la probabilità di valutazione delle stesse secondo una data sequenza di attributi. Tale ipotesi di comportamento evidenzia un'aleatorietà legata sia alla diversa sensibilità dei decisori rispetto ai singoli attributi (variabilità dell'ordine sequenziale di valutazione degli attributi), sia direttamente associabile alla fase compensativa del processo. Il modello parzialmente non compensativo sequenziale basato su soglie di accettabilità (SSA) è stato applicato ai dati raccolti durante l'indagine sul trasporto merci svolta in occasione del progetto di ricerca di rilevante interesse nazionale "Logistica e trasporti per i sistemi produttivi locali: metodi e modelli applicati alla realtà produttiva del nord-est padano ''. La capacità di previsione del modello SSA è stata confrontata, per le medesime situazioni, con quella propria dei modelli probabilistici compensativi legati al paradigma dell'utilità aleatoria (Logit). Si osserva come il modello SSA sia caratterizzato da una buona capacità di rappresentazione, superiore nel caso analizzato, a quella dei corrispondenti modelli di tipo Logit. A differenza di quest'ultimi, sembra descrivere in modo più completo i meccanismi di scelta degli utenti. È peraltro condivisibile la considerazione fatta da diversi studiosi, secondo i quali è facilmente ipotizzabile l'esistenza di individui il cui comportamento di scelta è più aderente al processo sequenziale ed altri molto più prossimi ad un processo di tipo compensativo. Vi è l'esigenza, a tal proposito, di capire quali possano essere le condizioni nelle quali un modello risulta più idoneo dell'altro. Potrebbe risultare interessante operare un'analisi finalizzata all'individuazione delle grandezze osservabili in base alle quali produrre efficaci segmentazioni della popolazione oggetto di studio, in modo da applicare il modello più idoneo alle specifiche situazioni, migliorando le prestazioni dello stesso e quindi i risultati in termini previsionali. In conclusione, anche alla luce di queste ultime considerazioni, sembra plausibile ammettere che i modelli non compensativi, quale il modello SSA, possono rappresentare un valido complemento ai classici n1odelli compensativi legati al paradigma dell'utilità aleatoria (in particolare i modelli Logit), in quanto permettono di cogliere strategie decisionali a fasi e quindi di rappresentare meglio l'eterogeneità comportamentale dei decisori. In tal senso l'evoluzione proposta, ovvero il modello di simulazione denominato SSA log-normale (in cui le soglie di accettabilità dei singoli attributi sono pensate quali variabili aleatorie distribuite secondo una log-normale ed il processo compensativo di scelta viene schematizzato mediante l'espressione della probabilità tipica di un modello Logit multinomiale ), rappresenta un interessante passo in avanti ed uno stimolo per successive ricerche.
XVII Ciclo
1973
Versione digitalizzata della tesi di dottorato cartacea. Nell'originale cartaceo mancano le pagg. 39-40