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On some regularity problems for kinetic-type equations
Get PDFIn this thesis we study some regularity problems for kinetic-type partial differential equations. These equations are characterized by the fact that their second order part is fully degenerate, but the presence of a first order operator restores good properties for the solution. In the first part of the thesis we consider a class of Backward Kolmogorov equations with rough coefficients, namely coefficients that are measurable in time and Hölder continuous in space. We prove optimal regularity for the fundamental solution and Schauder estimates for the Cauchy problem. In the second part we study boundary regularity for a kinetic Fokker-Planck equation with constant coefficients. We also prove a Nash inequality for kinetic Sobolev spaces
The intentional destruction of cultural heritage in international law
Get PDFLa tutela del patrimonio culturale è una delle grandi sfide del mondo contemporaneo, a causa delle immense implicazioni che la cultura, in tutte le sue manifestazioni materiali e immateriali, produce a livello politico, economico e sociale. Nel corso degli anni la trasmissione del patrimonio culturale è diventata progressivamente un tema centrale del dibattito internazionale, generando un interesse sempre più diffuso da parte della Comunità internazionale verso la protezione della cultura, in tutte le sue forme.
Tra le numerose minacce che attualmente affliggono la tutela del patrimonio culturale (guerre, cambiamenti climatici, sviluppo urbano, turismo di massa) e che sollecitano una risposta vigorosa da parte della Comunità internazionale, la soppressione e la distruzione intenzionale dei beni culturali è probabilmente la più grave e pressante.
Fin dalla sua fondazione, l’UNESCO ha promosso l’adozione di numerose convenzioni internazionali per prevenire la distruzione culturale in tempo di guerra, il traffico illecito di beni culturali, la protezione del patrimonio culturale mondiale e subacqueo, la salvaguardia delle culture viventi e la protezione della diversità delle espressioni culturali. Tuttavia, nonostante questo ricco e variegato sistema normativo, gli obblighi assunti dagli Stati in questo campo sono ancora prevalentemente basati su trattati, ossia fondati sul loro consenso espresso negli atti di ratifica o di adesione ai trattati pertinenti. Al contrario, la valutazione delle norme internazionali consuetudinarie in materia di protezione del patrimonio culturale dalle forme più gravi di distruzione è ancora incerta e richiede un’attenta indagine.
L’obiettivo del presente lavoro è inquadrare e valutare, in maniera critica, tutti gli strumenti di cui il diritto internazionale pubblico dispone per far fronte al fenomeno della distruzione intenzionale del patrimonio culturale, allo scopo di verificare la presenza, o l’eventuale stato di formazione, di una norma consuetudinaria che proibisca tali azioni distruttive, sia all’interno di un conflitto armato che in tempo di pace.The protection of cultural heritage is one of the great challenges of the contemporary world, due to the immense implications that culture, in all its tangible and intangible manifestations, has on the political, economic and social level. Over the years, the transmission of cultural heritage has progressively become a central theme of international debate, generating an increasingly widespread interest on the part of the international community in the protection of culture, in all its forms.
Among the many threats currently affecting the protection of cultural heritage (war, climate change, urban development, mass tourism) and calling for a vigorous response from the international community, the deliberate suppression and destruction of cultural heritage is probably the most serious and pressing.
Since its foundation, UNESCO has promoted the adoption of numerous international conventions to prevent cultural destruction in times of war, illicit trafficking of cultural properties, the protection of world cultural heritage and underwater cultural heritage, the preservation of living cultures and the protection of the diversity of cultural expressions. However, despite this rich and varied normative system, the obligations undertaken by States in this field are still predominantly treaty-based, i.e. founded on their consent expressed in acts of ratification or accession to the relevant treaties. On the contrary, the assessment of customary international rules regarding the protection of cultural heritage from the most serious forms of destruction is still uncertain and requires careful inquiry.
The aim of this work is to frame and critically assess all the instruments available in public international law to deal with the phenomenon of intentional destruction of cultural heritage, in order to ascertain the presence, or possible state of formation, of a customary norm prohibiting such destructive actions, whether in armed conflict or in peacetime
A fast cable-driven parallel robot for vision-assisted pick-and-place operations
Get PDFBin-picking (or 3D-picking) is a complex pick-and-place task that requires a robot to take products from a pile (usually contained in a box) and reposition them in the place area. This operation is often performed by manipulators with a serial architecture, which is characterized by high dexterity but limited dynamics.
Marchesini Group S.p.a. proposed the development of a bin-picking cell for feeding an automated packaging machine with lightweight products taken from a pile with productivity equal to 100pieces/min. The aim of this thesis is to develop the manipulator to be used in the aforementioned bin-picking cell.
Based on the constraints related to the coexistence of the robot with the vision system and the fast movements that the manipulator must perform to satisfy the required productivity, an overconstrained Cable-Driven Parallel Robot (CDPR) is proposed. The small footprint of the manipulator in the pick-up area facilitates the task of the vision system, and its parallel architecture in an overconstrained configuration guarantees high dynamic capabilities. The proposed CDPR has a configuration with 8 cables and 6 degrees of freedom, and it is called CORHDA: Cable-driven Overconstrained Robot for Highly Dynamical Applications.
The kinematic and dynamic models used to describe the manipulator are taken from the literature, whereas the conceptual and mechanical design of the robot prototype is carried out based on an example application. A new strategy is developed to properly control the manipulator without force sensors. The experimental tests on the prototype show that movements up to 8.8m/s and 255m/s^2 of velocity and acceleration are feasible, with cables always remaining taut. The manipulator is not yet sufficiently accurate for executing the bin-picking task but is highly repeatable. Accordingly, it is assumed that a future calibration of the robot geometric parameters will increase its positioning precision
Diffusing alpha particles radiation treatment optimization in clinical settings
Get PDFAlpha-particle emitters, notably used in 224Ra-DaRT, have emerged as effective in overcoming radiation resistance and providing targeted cancer therapy. These emitters cause DNA double-strand breaks, visualizable in human lymphocytes. The 224Ra DaRT technique, using a decay chain from seeds, extends alpha particle range, achieving complete tumor destruction while sparing healthy tissue.
This thesis examines a biokinetic model, validated with patient data, and a feasibility study on skin squamous cell carcinomas are discussed. The study reports 75% tumor complete response rate and 48% patients experiencing acute grade 2 toxicity, resolving within a month.
An observed abscopal effect (AE), where tumor regression occurs at non-irradiated sites, is examined, highlighting DaRT's potential in triggering anti-tumor immune responses. This effect, coupled with DaRT's high-linear energy transfer (LET), suggests its superiority over low-LET radiation in certain clinical scenarios.
Improvements to DaRT, including the use of an external radio-opaque template for treatment planning, are explored. This advancement aids in determining source numbers for optimal tumor coverage, enhancing DaRT’s safety. The thesis outlines a typical DaRT procedure, from tumor measurements to source assessment and administration, emphasizing the importance of precise seed positioning.
Furthermore, the thesis discusses DaRT's potential in treating prostate cancer, a prevalent global health issue, by offering an alternative to traditional salvage therapies. DaRT seeds, delivering alpha particle-based interstitial radiation, require precision in seed insertion due to their limited tissue range.
In conclusion, the thesis advocates for DaRT's role in treating solid tumors, emphasizing its improved radiobiological potency and potential benefits over beta and gamma source-based therapies. Ongoing studies are assessing DaRT's feasibility in treating various solid tumors, including pancreatic, breast, prostate, and vulvar malignancies, suggesting a promising future in cancer treatment
Methylation of PP2A and its role in transcriptional regulation
Get PDFPPP2A (Proteins Phosphatase) is one of the most abundant phosphatases in cells. It consists of three subunits: A “scaffolding” subunit, C “catalytic” subunit and B “regulatory” subunit (which determines the function of PP2A). PP2A activity is influenced by the methylation occurring at Leucine 309 of the C subunit. LCMT1 (Leucin-methyltransferase 1) and PPME1 (Protein Phospho-methylesterase 1) are the proteins responsible for the methylation and demethylation of PP2A, respectively.
Recently it has been shown that PP2A can be recruited to the chromatin by interacting with Integrator, a 15-subunit complex involved in RNA Polymerase II transcription regulation. PP2A, along with the kinase CDK9, is responsible for phosphorylation/dephosphorylation of the CTD of RNA Polymerase II, which determines the transition from pause-release to productive elongation.
Although today we know how Integrator and PP2A interact with each other and how PP2A is recruited, we do not know yet when this binding occurs and how changes in PP2A methylation can affect RNA Polymerase II activity; hence, the main question to be addressed is: does the methylation status of PP2A affect transcription? How? Through a proteomic and genomic approach, I will try to convince you that yes, the methylation status of PP2A affects not only transcription but also some post-transcriptional events
Stability and operation of power systems with a high share of renewable energy sources and storage systems at the transmission and distribution level
Get PDFThis thesis investigates two interrelated aspects of power systems with a high share of renewable energy sources and storage systems at both the transmission and distribution levels. The study comprises: i) enhancing frequency stability in transmission networks and ii) optimizing energy utilization within Renewable Energy Communities (RECs).
The first part of the dissertation focuses on developing a novel control architecture enabling wind power plants and grid-scale battery energy storage systems to provide synthetic inertial response, thereby addressing frequency stability concerns. By emulating the inertial response of traditional synchronous generators, wind turbines utilize kinetic and electrostatic energy to stabilize grid frequency. Simulation studies conducted on benchmark networks and real-world transmission grids demonstrate the effectiveness of the proposed control scheme in improving both small-signal and transient stability.
In the second part, the thesis delves into the operational management of RECs, proposing and validating an Energy Management System (EMS) to optimize energy distribution within these communities. The EMS operates in real-time, leveraging forecasted energy production, consumption data, and market prices to minimize procurement costs while maximizing renewable energy utilization. Extensive testing using Software-in-the-Loop (SIL) and Power Hardware-in-the-Loop (PHIL) configurations validates the system's reliability and effectiveness in real-world REC scenarios. Challenges such as establishing a robust online metering network and dependency on accurate forecast data are discussed, providing insights for future development.
The research contributes valuable insights into the evolving landscape of power systems with significant RES integration. The proposed control architecture and validated EMS offer practical solutions for addressing current and future challenges in renewable energy management. Furthermore, the adaptability of the EMS to evolving regulatory frameworks underscores its potential for broader implementation across different regions. This research sets the stage for further advancements in enhancing the resilience and reliability of renewable energy systems in power networks
Categorization of sleep apneas in different mouse models of human diseases
Get PDFIntroduction. Sleep apnea is a common breathing disorder. Apneas are categorized, based on the origin, as central (CSA), when there is an impaired transmission of the signal for inspiration, or as obstructive (OSA), when an airway obstruction occurs. This condition is prevalent in patients with Down Syndrome (DS), CDKL5 deficiency disorder (CDD), and Pierre Robin sequence (PRS). Therefore, we investigate whether the mouse models of DS (Ts65Dn mice, TS), CDD (CDKL5-knockout mice, CDKL5-KO), and PRS (BMP7-knockout, BMP7-KO mice) could replicate the respiratory disturbances observed in human patients.
Methods. Experiments were performed on 12 TS mice and 14 euploid controls (EU) for the model of DS, 14 CDKL5-KO and 10 wild-type mice (CDKL5-WT) for the model of CDD, and 3 BMP7-KO and 3 control mice (BMP7-WT) for the model of PRS. Each mouse was implanted with specific electrodes for sleep stage discrimination and diaphragmatic activity (DIA) detection and was recorded inside a whole-body plethysmograph (WBP) for 8 hours during the light (resting) period. Sleep and respiratory phenotypes were assessed and apneas occurring during sleep were categorized as either CSA or OSA based on DIA and WBP signals.
Results. TS mice had a decreased occurrence rate of CSA during non-rapid-eye-movement sleep (NREMS) and a higher occurrence rate of apneas with an obstructive component during rapid-eye-movement sleep (REMS), compared to EU. Similarly, CDKL5-KO mice had an augmented occurrence rate of OSA during REMS, whereas no differences were observed for CSA, compared to CDKL5-WT.
Preliminary data on BMP7-KO mice indicated an increased occurrence rate of CSA during NREMS, as well as of both CSA and OSA during REMS, compared to BMP7-WT mice.
Conclusions. Mice exhibited varying degrees of airway obstruction like humans. Therefore, TS and CDKL5-KO mice, recapitulating DS and CDD, are valid models of OSA, whereas BMP7-KO mice, mimicking PRS, require further investigation
Versatile electrostatic transducers: experimental investigation into adhesion, sensing, energy generation, and actuation
Get PDFElectrostatic Transducers (ESTs) are increasingly being utilized in various applications such as adhesive films, sensors, actuators, and energy generators. They operate based on electrostatic interaction within a dielectric medium and are advantageous due to high efficiency, low manufacturing cost, and low energy consumption. However,
the need for high electric fields has posed material challenges that limit their development. Advances in manufacturing and novel dielectric materials, specifically
Electro-active polymers (EAPs) are enabling progress in this technology. This thesis focuses on enhancing ESTs by exploring new designs, material selection, and manufacturing methods. An Electro-Adhesive Device (EAD) is introduced for gripper applications, capable of generating a pressure of 12kPa at an activation voltage of 9kV on a paper substrate. The EAD is tested on a DELTA robot to validate its practical
application. The study also examines electrostatic sensors (ESSs), comparing parallel and interdigitated electrode configurations for capacitive bending sensors. Dielectric elastomer-based goniometer sensors (GDES) for human joint angle measurement and proximity bumper sensors for human-robot collision prevention are introduced. Performance
metrics are empirically validated. An electric generator utilizing dielectric elastomers (DEG) is proposed for ocean wave energy harvesting. It features spray-coated, silicone-based electrodes and insulators and is characterized through wave-simulator and laboratory tests. The DEG shows energy
conversion efficiencies exceeding 90% at 5kV and 75% at 15kV. Lastly, a linear Electrostatic Motor (ESM) is developed, featuring two passive slider configurations based on dielectric (DPS) and conductive (CPS) materials. Simulation and empirical tests demonstrate that the CPS configuration produces a consistent output force of 0.24N at a 2kV sine wave amplitude, and excellent speed tracking up to 36mm/s. Summarily, this thesis contributes to the field of ESTs by addressing several of the existing challenges, with a focus on device design, simulation, material selection, manufacturing processes, and test, paving the way for broader industrial applications
L'apprendimento della seconda lingua in classi multiculturali di scuole secondarie in Italia e Spagna: un'analisi del pensiero e dell'azione degli insegnanti
Get PDFPartiendo del estado del arte de la formación del profesorado para alumnos de origen inmigrante y de la legislación europea, italiana y española, este trabajo pretende investigar con tres herramientas de análisis (cuestionario, entrevistas en profundidad y observación de campo) las actitudes de los profesores en las aulas multiculturales de un centro de Bolonia y otro de Valencia.Partendo dallo stato dell'arte della formazione dei docenti per alunni con background migratorio e dalla normativa europea, italiana e spagnola; questo lavoro vuole indagare con tre strumenti di analisi (questionario, interviste in profondità e osservazione sul campo) gli atteggiamenti dei docenti nelle aule multiculturali in una scuola di Bologna e in una di Valencia.Starting from the state of the art of teacher training for pupils with a migrant background and from European, Italian and Spanish legislation, this work aims to investigate with three analysis tools (questionnaire, in-depth interviews and on-campus observation) the attitudes of teachers in multicultural classrooms in a school in Bologna and one in Valencia
Zirconia-based catalytic systems for the valorisation of biomass in chemical products of high industrial interest: an experimental and computational study
Get PDFZirconia is a particularly promising material as heterogeneous catalyst: in fact, thanks to its innumerable properties, it can be used for a large number of reactions, both as an actual catalyst and as a support for nanoparticles. In this thesis work various reactions for the valorisation of biomass were studied using zirconia-based catalysts in the gas phase and liquid phase. The hydrogenation reaction of methyl levulinate (ML) in continuous gas phase by CTH mechanism was studied, using alcohols such as H-donor. For this reaction, the two crystalline phases of zirconia were compared, the tetragonal (t-ZrO2) and the monoclinic (m-ZrO2): these were synthesized and subsequently characterized. From the catalytic tests carried out, t-ZrO2 resulted to be more active in the reaction in question and more selective towards the formation of GVL (yield of 63%). m-ZrO2, however, was found to deactivate more quickly. Material characterizations combined with computational and NMR spectroscopy studies have made it possible to explain the reasons for a faster deactivation of the monoclinic phase compared to the tetragonal one. Other zirconia-based materials with higher surface areas, compared to crystalline zirconia, have been subsequently tested, with the aim of pushing the reaction further towards consecutive products, such as Pentenoates, products interested in obtaining Pentanoates.
Catalysts based on metal nanoparticles of Au and Pd (both mono and bimetallic) supported on commercial zirconia were synthesized using the sol-immobilization technique. These have been tested for the liquid phase hydrogenation of furfural by CTH mechanism using isopropanol as H-donor and the oxidation reaction of HMF in the liquid phase.
Finally, the oxidation reaction of glucose to glucaric acid was studied computationally, modelling some gold clusters of 55 atoms and studying on them the adsorption of some target molecules for the reaction, to obtain interesting information on deactivation phenomena during the reaction in question