10081 research outputs found
Sort by
Wireless Power Link Design for Both High-Power Inductive Coupling and Smart Metasurfaces Exploitation
Get PDFAs future technologies are going to be autonomous under the umbrella of the Internet of things (IoT) we can expect WPT to be the solution for intelligent devices. WPT has many industrial and medical applications both in the near-field and far-field domains. Considering the impact of WPT,
this thesis is an attempt to design and realize both near-field and far-field WPT solutions for different application scenarios.
A 27 MHz high frequency inductive wireless power link has been designed together with the Class-E switching inverter to compensate for the efficiency loss because of the varying weak coupling between transmitter
and receiver because of their mutual misalignment. Then a system of three coils was introduced for SWIPT. The outer coil for WPT and the inner two coils were designed to fulfil the purpose of communication and testing, operating at frequencies different from the WPT coil. In addition to that, a trapping filter technique has also been adopted to ensure the EM isolation
of the coils.
Moreover, a split ring resonator-based dual polarization converter has been designed with good efficiency over a wide frequency range. The gap or cuts have been introduced in the adjacent sides of the square ring to make it a dual-polarization converter. The converter is also stable over a wide range of incident angles.
Furthermore, a meta-element based intelligent surface has been designed to work in the reflection mode at 5 GHz. In this research activity, interdigital capacitors (IDCs) instead of ICs are introduced and a thin layer of the
HfZrO between substrate and meta elements is placed whose response can be tuned and controlled with the applied voltage to achieve IRS
Metamorphoses of Endymion and Selene: Dominance, Objectification, and Necrophilia
No full textThe aim of the research is to understand the transformations of the myth of Endymion and Selene from the Ancient World to the Contemporary Times with regard to the intersection of dominant femininity and objectified masculinity. The final goal is to show how these two macro-concepts have been represented according to a dialectical mechanism of cultural constants and variations of which the myth stands as a privileged plane of study. This connection will be explored in detail alongside with the eroticization of the sleeping and dead male body, to which its erotic agency is to be restored, by a woman who explicitly shows an erotic desire towards him. These two marginal desires are analysed from the point of view of the dialectic antagonistic to hegemony, and their expressive effects are examined in different media: literary, artistic, cinematographic. This relationship between the two lovers is marked by a significant presence of death that in the first part of the thesis is called female proto-necrophilia, while in the last part is named female necrophilia. The relationship that is in established between the two is a clear example of how anti-normative desires have undergone numerous attempts of neutralization and have increasingly become an expression of the medicalization of the uncanny. Female necrophilia is in fact the last step of a mythical romance that undermines the normative and hegemonic construction of ordinariness, but at the same time manifests its expressive and irrepressible power throughout the literature and arts of the Global North.
To examine this in depth, the research is divided into five chapters.Lo scopo della presente ricerca è la comprensione delle trasformazioni del mito di Endimione e Selene a partire dal mondo antico fino alla contemporaneità, con un focus sull’intersezione dei temi della femminilità dominante e della maschilità oggettivata. L’obiettivo finale è quello di mostrare come questi due macro-concetti siano stati rappresentati secondo un meccanismo dialettico di costanti e varianti culturali rispetto ai quali il mito costituisce un elemento trasversale di studio privilegiato. La connessione sarà indagata soprattutto in relazione con l’erotizzazione del corpo maschile addormentato e morto, a cui una donna con un desiderio erotico esplicito nei suoi confronti, intende restituire la sua agency erotica. Questi due desideri marginali sono analizzati in chiave di dialettica antagonistica all’egemonia, e ne sono esaminate le ricadute espressive all’interno di diversi media: letterari, artistici, cinematografici. La relazione tra i due amanti, in particolare, è connotata da una forte presenza di morte, che nella prima parte della tesi è chiamata protonecrofilia, nell’ultima parte necrofilia femminile. La relazione che si instaura tra i due è infatti un chiaro esempio di come i desideri anti-normativi siano stati sottoposti a tentativi di normalizzazione e siano al contempo diventati espressione della medicalizzazione del per- turbante. La necrofilia femminile è l’ultimo passaggio di una storia mitica che mette in crisi la costruzione normativa ed egemonica della realtà ordinaria, ma che al contempo manifesta la sua forza espressiva e insopprimibile nel corso di tutta la letteratura e arte del Global North.
L'elaborato è diviso in cinque capitoli
Magnetic Resonance Imaging-Derived biomarkers of Isocitrate-Dehydrogenase mutation in diffuse gliomas: a conventional MR and Diffusion Weighted Imaging study.
Get PDFThe introduction of molecular criteria into the classification of diffuse gliomas has added interesting practical implications to glioma management. This has created a new clinical need for correlating imaging characteristics with glioma genotypes, also known as radiogenomics or imaging genomics. Whilst many studies have primarily focused on the use of advanced magnetic resonance imaging (MRI) techniques for radiogenomics purposes, conventional MRI sequences still remain the reference point in the study and characterization of brain tumours. Moreover, a different approach may rely on diffusion-weighted imaging (DWI) usage, which is considered a “conventional” sequence in line with recently published directions on glioma imaging. In a non-invasive way,
it can provide direct insight into the microscopic physical properties of tissues. Considering that Isocitrate-Dehydrogenase gene mutations may reflect alterations in metabolism, cellularity, and angiogenesis, which may manifest characteristic features on an MRI, the identification of specific MRI biomarkers could be of great interest in managing patients with brain gliomas.
My study aimed to evaluate the presence of specific MRI-derived biomarkers of IDH molecular status through conventional MRI and DWI sequences
Development of an Augmented Reality system applied to a 3D model of the prostate, in order to facilitate the dissection of the tumor and the preservation of the neuro-vascular bundles during robotic-assisted radical prostatectomy.
Get PDFLa realtà aumentata (AR) è una nuova tecnologia adottata in chirurgia prostatica con l'obiettivo di migliorare la conservazione dei fasci neurovascolari (NVB) ed evitare i margini chirurgici positivi (PSM). Abbiamo arruolato prospetticamente pazienti con diagnosi di cancro alla prostata (PCa) sul base di biopsia di fusione mirata con mpMRI positiva. Prima dell'intervento, i pazienti arruolati sono stati indirizzati a sottoporsi a ricostruzione del modello virtuale 3D basato su mpMRI preoperatoria
immagini. Infine, il chirurgo ha eseguito la RARP con l'ausilio del modello 3D proiettato in AR all'interno della console robotica (RARP guidata AR-3D).
I pazienti sottoposti a AR RARP sono stati confrontati con quelli sottoposti a "RARP standard" nello stesso periodo.
Nel complesso, i tassi di PSM erano comparabili
tra i due gruppi; I PSM a livello della lesione indice erano significativamente più bassi nei pazienti riferiti al gruppo AR-3D (5%) rispetto a quelli nel gruppo di controllo (20%; p = 0,01). La nuova tecnica di guida AR-3D per l'analisi IFS può consentono di ridurre i PSM a livello della lesione dell'indiceAugmented reality (AR) is a novel technology adopted in prostatic surgery with the aim to improve the preservation of neurovascular bundles (NVBs) and avoid Positive surgical margins (PSM).We prospectively enrolled patients with a diagnosis of prostate cancer (PCa) on the basis of positive mpMRI-targeted fusion biopsy.Prior to the intervention, patients enrolled were addressed to undergo 3D virtual model reconstruction based on preoperative mpMRI
images. Finally, the surgeon performed RARP with the help of the 3D model projected in AR inside the robotic console (AR-3D guided RARP).
Patients who underwent AR RARP were compared to those who underwent "standard RARP" in the same period.
Overall, PSM rates were comparable
between the two groups; PSMs at the level of the index lesion were significantly lower in patients referred to AR-3D group (5%) than those in the control group (20%; p = 0.01).The novel technique of AR-3D guidance for IFS analysis may allow for reducing PSMs at the level of the index lesion
Constructed wetlands for water management and reuse in agriculture
Get PDFGlobal warming mainly induced by anthropogenic causes has already restricted the increase in agricultural productivity along with aggravating the conflict between water supply and demand. In this context, constructed wetlands (CWs) can be one of nature-based solutions for the treatment and reuse of unconventional wastewater sources. The aim of this research was to evaluate the performance of CWs in wastewater treatment (i.e., agricultural drainage water and domestic wastewater) and to explore the potential of their effluents for agricultural reuse. In order to achieve this goal, the work based on literature review and experimental approach was carried out. The findings showed that CWs can be an effective option for treating both agricultural drainage water (ADW) and domestic wastewater. It was also found that systems treating ADW can be effective even after a long period of operation. The treatment performance of CW systems is affected by the design and operational factors. For instance, the application of simple hydraulic structures and vegetation establishment can improve the pollutant removal efficiencies by increasing hydraulic retention time. Moreover, the addition of other technologies (e.g., UV treatment, anaerobic reactors) could further improve the quality of wastewater treated by single-stage CWs. In particular, it is strongly recommended to add special disinfection technologies to CW treatment systems to meet agricultural reuse standards since it was shown that the microbial loads often exceed the limits (e.g., E. coli)
Development of predictive energy management strategies for hybrid electric vehicles supported by connectivity
Get PDFNowadays, the spreading of the air pollution crisis enhanced by greenhouse gases emission is leading to the worsening of the global warming. In this context, the transportation sector plays a vital role, since it is responsible for a large part of carbon dioxide production.
In order to address these issues, the present thesis deals with the development of advanced control strategies for the energy efficiency optimization of plug-in hybrid electric vehicles (PHEVs), supported by the prediction of future working conditions of the powertrain.
In particular, a Dynamic Programming algorithm has been developed for the combined optimization of vehicle energy and battery thermal management. At this aim, the battery temperature and the battery cooling circuit control signal have been considered as an additional state and control variables, respectively. Moreover, an adaptive equivalent consumption minimization strategy (A-ECMS) has been modified to handle zero-emission zones, where engine propulsion is not allowed.
Navigation data represent an essential element in the achievement of these tasks. With this aim, a novel simulation and testing environment has been developed during the PhD research activity, as an effective tool to retrieve routing information from map service providers via vehicle-to-everything connectivity.
Comparisons between the developed and the reference strategies are made, as well, in order to assess their impact on the vehicle energy consumption.
All the activities presented in this doctoral dissertation have been carried out at the Green Mobility Research Lab} (GMRL), a research center resulting from the partnership between the University of Bologna and FEV Italia s.r.l., which represents the industrial partner of the research project
Colocated multiple-input multiple-output radars for smart mobility
Get PDFIn recent years, radars have been used in many applications such as precision agriculture and advanced driver assistant systems. Optimal techniques for the estimation of the number of targets and of their coordinates require solving multidimensional optimization problems entailing huge computational efforts. This has motivated the development of sub-optimal estimation techniques able to achieve good accuracy at a manageable computational cost. Another technical issue in advanced driver assistant systems is the tracking of multiple targets. Even if various filtering techniques have been developed, new efficient and robust algorithms for target tracking can be devised exploiting a probabilistic approach, based on the use of the factor graph and the sum-product algorithm.
The two contributions provided by this dissertation are the investigation of the filtering and smoothing problems from a factor graph perspective and the development of efficient algorithms for two and three-dimensional radar imaging. Concerning the first contribution, a new factor graph for filtering is derived and the sum-product rule is applied to this graphical model; this allows to interpret known algorithms and to develop new filtering techniques. Then, a general method, based on graphical modelling, is proposed to derive filtering algorithms that involve a network of interconnected Bayesian filters. Finally, the proposed graphical approach is exploited to devise a new smoothing algorithm. Numerical results for dynamic systems evidence that our algorithms can achieve a better complexity-accuracy tradeoff and tracking capability than other techniques in the literature. Regarding radar imaging, various algorithms are developed for frequency modulated continuous wave radars; these algorithms rely on novel and efficient methods for the detection and estimation of multiple superimposed tones in noise. The accuracy achieved in the presence of multiple closely spaced targets is assessed on the basis of both synthetically generated data and of the measurements acquired through two commercial multiple-input multiple-output radars
Inherited optic neuropathies: working on mitochondrial bioenergetics and dynamics to discover new therapeutic strategies
Get PDFInherited optic neuropathies are neurodegenerative disorders characterized by mitochondrial dysfunctions. Leber’s Hereditary Optic Neuropathy (LHON) and Dominant Optic Atrophy (DOA) are caused by mutations in respiratory complex I (CI) core subunits and OPA1 mutations, respectively and there is no established cure. For LHON the only approved drug is idebenone but its antioxidant effects depend on its reduced form feeding electrons to CIII. NAD(P)H-quinone dehydrogenase (NQO1), an inducible cytosolic enzyme, is involved in the antioxidant response through reduction of quinones, though clear evidence about its role is still lacking. DOA is caused by mutations in OPA1 gene encoding a mitochondrial GTPase involved in mitochondrial functions. First, we show that in LHON cellular models overexpressing NQO1, idebenone treatment rescues rotenone-sensitive mitochondrial respiration and ATP synthesis, as well as reducing ROS production. This demonstrates NQO1 supports oxidative phosphorylation bypassing CI and directly transfers electrons to CIII via the NQO1-idebenone-CIII pathway. Indeed, only patient-derived fibroblasts expressing NQO1 are able to maintain respiration. Finally, treatment with NQO1 inducer dimethyl fumarate allows mitochondrial respiration in the presence of idebenone, demonstrating the correlation between NQO1 expression and the efficacy of idebenone. Subsequently, we aim to validate FDA-approved molecules, “OPA1 rescuing molecules” (ORMs), able to rescue the mitochondrial dysfunctions induced by OPA1 mutations. Here, we show the testing of six selected compounds in Opa1-ablated mouse embryonic fibroblasts (MEFs) expressing the human OPA1 isoform1 bearing the R445H and D603H mutations. Some of these molecules ameliorate the bioenergetics and/or the mitochondrial morphology, depending on the mutation. ORM14 is the most effective compound showing both energy and morphology rescuing in the final validation on patient-derived fibroblasts. Our results permit the translation into clinic of the biochemical findings on the role of NQO1 for LHON treatment, as well as “drug repurposing” for DOA
Modular Multilevel Converters With Interleaved Half-Bridge Submodules
Get PDFModular multilevel converter (MMC) has a prominent potential to take over the high-power converter market thanks to its exceptional characteristics, including modularity, flexibility to adapt to any voltage level, significant reduction in average switching frequency without compromising remarkable harmonic performance and many other. However, due to structural constraints of the existing submodule arrangements in classical MMCs the power scalability at submodule levels is limited. To address this issue, this PhD thesis reports a novel Modular Multilevel Converter with Interleaved half-bridge Sub-Modules (ISM-MMC). The ISM-MMC exhibits a higher modularity and scalability in terms of current ratings with respect to conventional MMCs, while preserves the typical voltage level adaptiveness. The ISM-MMC brings the known advantages of classical MMC to low/medium-voltage, high-current applications, where classical MMCs are rarely used. A detailed description of operating principle along with the converter’s average model, outer and internal control methods, a hybrid modulation scheme that helps to exploit advantages of the interleaving scheme and converter efficiency analysis are given in this thesis. This dissertation also concerns a current balancing problem that is typical in interleaved converters, while it is very new issue in MMC-based structures. The problem has been rigorously studied and a new control strategy, which relies on interleaved currents estimation, has been proposed in this work. This technique minimizes the number of required current sensors in ISM-MMC, thereby reducing the converter’s cost, weight, and volume. To make operation of such current regulators possible, a new capacitor voltage balancing strategy suitable for both ISM-MMCs and conventional MMCs is developed. Extensive numerical simulations, hardware-in-the-loop, and experimental tests on a scaled-down, single-phase ISM-MMC laboratory prototype are carried out to demonstrate the feasibility of the proposed topology, implemented modulation and control schemes
Design and evaluation of aerosol and liquid separation systems
Get PDFConventional chromatographic columns are packed with porous beads by the universally employed slurry-packing method. The lack of precise control of the particle size distribution, shape and position inside the column have dramatic effects on the separation efficiency. In the first part the thesis an ordered, three-dimensional, pillar-array structure was designed by a CAD software. Several columns, characterized by different fluid distributors and bed length, were produced by a stereolithographic 3D printer and compared in terms of pressure drop and height equivalent to a theroretical plate (HETP). To prevent the release of unwanted substances and to provide a surface for immobilizing a ligand, pillars were coated with one or more of the following materials: titanium dioxide, nanofibrillated cellulose (NFC) and polystyrene. The external NFC layer was functionalized with Cibacron Blue and the dynamic binding capacity of the column was measured by performing three chromatographic cycles, using bovine serum albumin (BSA) as target molecule.
The second part of the thesis deals with Covid-19 pandemic related research activities. In early 2020, due to the pandemic outbreak, surgical face masks became an essential non-pharmaceutical intervention to limit the spread. To address the consequent shortage and to support the reconversion of the Italian industry, in late March 2020 a multidisciplinary group of the University of Bologna created the first Italian laboratory able to perform all the tests required for the evaluation and certification of surgical masks. More than 1200 tests were performed on about 350 prototypes, according to the standard EN 14683:2019. The results were analyzed to define the best material properties and masks composition for the production of masks with excellent efficiency. To optimize the usage of surgical masks and to reduce their environmental burden, the variation of their performance over time of usage were investigated as to determine the maximum lifetime