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Management and control of energy storage systems for stationary and automotive applications
Get PDFThis PhD dissertation has presented a number of scenarios in which Energy Storage Systems (ESSs)
can be usefully employed for increasing energy system performances. Particularly, after introducing
the State-of-the-Art of ESS technologies (Chapter 1), reference has been made to some stationary and
automotive applications. Stationary applications have regarded Renewable Energy Sources (RESs)
exploitation issues and EV integration within micro-grids (Chapter 2). It has been shown that ESSs
are particularly useful in compensating for RES forecasting errors, whereas they are much less
effective as energy buffers. In addition, Vehicle to Grid (V2G) has also been revealed as an
alternative and viable solution for increasing RES penetration level and micro-grid autonomy, even in
presence of small EV fleets. The promising results obtained in the energy management of power
systems by means of the use of V2G and G2V paradigm have suggested the integration of Electric
Vehicles (EVs) into the power system. This requires that EV energy storage systems should satisfy
both electric propulsion and power system requirements. With this aim, the design and management
of a novel Hybrid Energy Storage System (HESS) for EVs has been considered (Chapter 3).
Particularly, the proposed configuration allows the reduction of the peak current delivered by EV
batteries, thus preserving their rated performances and increasing their lifetime. This goal has been
achieved by means of a suitable management of the energy flows provided by the HESS, leading to a
good exploitation of the proposed topology. The effectiveness of the proposed solutions has been
verified through several extensive simulation studies, which have been carried out in the Matlab
environment.
In conclusion, it can be stated that all cases have revealed the need of carefully sizing and managing
ESSs in order to achieve optimal results. In this context, it is worth noting that the employment of
large ESS easily leads to enhanced performances but also to significant increased costs. This
drawback cannot be sustained, especially in automotive applications, in which EV competitiveness is
strictly related to a decrease of ESS size, weight and costs. On the other hand, small ESSs do not
generally guarantee the same performances but they can be quite similar if optimal management and
control strategies are employed. These last thus will cover a fundamental role in making ESS more
widespread, enabling an optimal trade-off among increased performances, costs, management and
control issues
Topology matters: characteristics of functional brain networks in healthy subjects and patients with Epilepsy, Diabetes, or Amyotrophic Lateral Sclerosis during a resting-state paradigm.
Get PDFThe brain can be seen as a complex structural and functional network. Cognitive functioning strongly depends on the organization of functional brain networks. EEG/MEG resting-‐state functional connectivity and functional brain networks studies attempt to characterize normal brain organization as well as deviation from it due to brain diseases. Despite the impact on the understanding of brain functioning that these tools provided, there are still methodological hurdles that might compromise the quality of the results. The main aim of this thesis was to gain an understanding of the role of functional connectivity and network topology on brain functioning by: (i) addressing the methodological issues intrinsic in the analysis that can bias the results; (ii) quantifying functional connectivity differences possibly induced by brain impairments; (iii) detecting and quantifying how network topology changes, due to brain impairments. In order to achieve these objectives, functional connectivity and functional brain networks obtained by empirical recordings were reconstructed. Recordings were acquired with different modalities (EEG or MEG) and under different pathologies: epilepsy, diabetes and amyotrophic lateral sclerosis. Specifically three research questions were addressed: • Do functional brain network architectures obtained from pharmaco-‐resistant epileptic patients responding to vagal nerve stimulation (VNS) change compared to patients not responding to VNS? • Are functional connectivity alterations related to cognitive performance and clinical status in type I diabetes mellitus patients? • Is functional network topology related to disease duration in amyotrophic lateral sclerosis patients? In order to answer these questions, avoiding possible biases which may affect the results, two key choices were made: first, the selection of the phase lag index [1] as functional connectivity estimator because it is less sensible to common sources problem; second, the application of minimum spanning tree (MST) [2] approach to overcome the problem of network comparison and characterize network topology reliably. In summary, this thesis confirms that alterations of functional connectivity and functional brain networks in disease may be used as potential biomarkers for more objective diagnosis and the choice of effective treatment options. Specifically, in epileptic patients implanted with VNS the relation between network measures and clinical benefit suggest that these measures can be used as a marker in monitoring the efficacy of the treatment; in amyotrophic lateral sclerosis the relation between disease duration and whole brain network disruption suggests diagnostic relevance of network measures in evaluating and monitoring the disease; and finally in type 1 diabetic mellitus patients functional connectivity measures can be complementary to cognitive tests and may help to monitor the effect of T1DM on brain functions
The role of neurofilament-light polipeptide (NEFL) in the onset and progression of hepatocellular carcinoma
Get PDFBackground: Hepatocellular Carcinoma (HCC) is the third cause of cancer-related deaths worldwide and a major health problem. Although many factors, including chromosomal anomalies, genetic polymorphisms, genetic and epigenetic alterations, contribute to HCC onset and progression, the exact mechanisms remain largely unclear. Recently, it has been shown that NEFL gene (Neurofilament-light polypeptide), whose mutations are responsible of motor-neuron disease such as Charcot-Marie-Tooth disease type 2E, is also involved in some types of malignancies. However, no information about NEFL and HCC are available.
Aim: Aim of this study was to investigate the role of NEFL in the several stages of HCC development in the Resistant-Hepatocyte (R-H) rat model of hepatocarcinogenesis.
Results: microarray analysis and qRT-PCR analysis showed that the expression of NEFL was strongly up-regulated at all stage of the multistep process of hepatocarcinogenesis, including the very early ones, in particular NEFL mRNA was strongly up-regulated in KRT-19 positive preneoplastic lesions and in fully malignant HCCs. In agreement with mRNA levels, immunofluorescence studies identified the neurofilament only in the preneoplastic lesions positive for KRT-19 and in early HCCs. Since the presence of this neurofilament has never been described in the liver, we wished to investigate whether NEFL expression in the carcinogenic process could be the result of a re-acquisition of fetal/neonatal life status or of increased proliferative capacity of the hepatocytes. However, almost undetectable levels of mRNA were observed in the liver of 19 days fetuses or 2 days pups. Moreover, no NEFL up-regulation was observed in actively dividing hepatocytes in liver regeneration occurring following two/third partial hepatectomy (PH), suggesting that NEFL expression in the liver is a specific feature of cancer onset and development. The ectopic expression of NEFL at all stages of rat carcinogenesis implies that NEFL may function as an oncogene in the onset and development of HCC. To assess the clinical significance of NEFL expression in human HCC patients, we determined NEFL mRNA levels in 14 HCC patients. The results showed that, similarly to what observed in the rat model, while NEFL expression was undetectable in normal human liver, it was readily detectable in HCCs and in matched cirrhotic liver. This demonstrates that aberrant expression of NEFL takes place at the onset and progression in human hepatocarcinogenesis, translating our findings to human pathology. Interestingly, although not statistically significant, a clear trend towards an up-regulation of NEFL in HCCs when compared to matched cirrhotic tissue was observed. Notably, when patients were divided into two groups, NEFL low- or high-expressors, based on the median expression level, the results showed that time of recurrence was significantly shortened in high-NEFL expression compared to low-NEFL expression group, thus demonstrating that NEFL expression levels are a predictive factor for HCC prognosis. Searching for possible mechanisms underlying NEFL enhanced expression, and to determine if the up-regulation of NEFL in the carcinogenic process could be related to promoter methylation status, we analyze the CpG island described in UCSC Genome browser in the 5’ flanking genomic region of NEFL gene. Analysis of the methylation status of 10 consecutive CpG dinucleotides in 5 HCC and 3 normal rat livers exhibited no differences in the methylation status in HCC and controls. These results suggest that DNA hypomethylation of the NEFL promoter region is not involved in the regulation of the expression of this gene. Moreover, no change in NEFL-targeting microRNAs could be found in pre- or neoplastic lesions compared to normal liver.
Conclusions: These results unveil the yet unknown role of NEFL in the onset and development of HCC and suggest that NEFL could act as an oncogene in the liver. Further studies are required to identify the mechanism(s) involved in regulating the expression of the NEFL gene and their exact role in HCC development. A better knowledge of the role of NEFL might hopefully provide a novel therapeutic target in HCC progression
Effect of antidepressants and adolescent stress on catecholamine transmission in the rat bed nucleus of stria terminalis (BNST): a microdialysis study
Get PDFRationale: Antidepressants include a relatively wide spectrum of drugs that increase the
synaptic concentration of monoamines, mostly through neurotransmitter reuptake
blockade. The bed nucleus of stria terminalis (BNST) is considered a relay station in
mediating the activation of stress response but also in the acquisition and expression
of emotions. Chronic stress, particularly at developmental stage, has long-lasting
deleterious effects on several cortico-limbic areas. Abnormal catecholamine
transmission in the BNST evoked by chronic stress exposition at peri-adolescent age
may be interpreted as relevant neurochemical marker at the onset of adolescent or
adult depression. BNST is richly innervated by monoamines and sends back
projections to the nucleus of origin. We previously showed that the administration of
selective blockers of norepinephrine transporter (NET) increases the extracellular
concentration (output) of dopamine, suggesting that dopamine could be captured by
NET in the BNST. Among new experimental strategies investigated for the theraphy of
depression, the treatment with sub-anesthetic doses of ketamine has been suggested to
be one of the most promising.
Objectives: The aims of this study, carried out by means of in vivo microdialysis, were:
(i) ascertain the acute effects that antidepressants with varying mechanisms of action
have on dopamine and norepinephrine output in the BNST; (ii) ascertain the acute
effects that sub-anesthetic doses of ketamine have on dopamine and norepinephrine
output in the BNST; (iii) ascertain whether peri-adolescent unpredictable chronic
stress could produce changes in dopamine and norepinephrine transmission in the
BNST.
Results: We observed the following: (i) all the antidepressants tested (5-20 mg/Kg i.p.)
increased the output of catecholamines, dose dependently; (ii) ketamine (10-40 mg/Kg
i.p.) increased the output of catecholamines, dose dependently; (iii) peri-adolescent
unpredictable chronic stress determined changes of basal and stimulated
catecholamine output.
Conclusions: These results suggest that catecholamine transmission in the BNST may
be part of a common downstream pathway that is involved in the action mechanism of
antidepressants, and in the effects of stress. Consequently, it is hypothesized that a
dysfunction of neuronal transmission in this brain area may have a role in the etiology
of affective disorders
Sviluppo e caratterizzazione di materiali innovativi a base di idrossiapatite e vetro bioattivo
Get PDFThe difference in purity, particle size, microstructure, and thermo-chemical stability of three commercially available hydroxyapatite powders are found to play an important role during their consolidation using Spark Plasma Sintering (SPS) as well as strongly affect the characteristics of the resulting sintered bodies. A fully dense material without secondary phases was obtained by SPS at 900°C, when using the relatively small sized, with refined grains and high purity powders. The sintered product, consisting of sub-micrometer sized hydroxyapatite grains, displayed optical transparency and good mechanical properties.
In contrast, the higher temperature levels (up to 1200 °C) needed to sinter powders with larger particles, or finer ones which contain additional phases, lead to products with coarser microstructures and/or significant amount of β-TCP as a result of HAp decomposition. Optical characteristics, hardness and elastic modulus of the resulting sintered samples are correspondingly worsened.
Thanks to the favorable response bioglass materials display during their interaction with biological tissues, they have become one of the most important and investigated class of ceramics for biomedical application. In particular, as a consequence of the several chemico-physical phenomena involved at the glass-physiological fluids interface, a bone-like hydroxycarbonate apatite (HCA) layer is formed on the biomaterial surface, so that a strong bond between the latter one and tissues can be established.
It is well known that mechanical and biological properties of bioactive glasses are significantly affected by the relative amounts among the different oxide constituents as well as the sintering conditions adopted to consolidate the initial amorphous powders. One of the most important aspect to consider in this regard is represented by the tendency of the material to crystallize during heat treatments, as the extensive crystallization of the bioglass negatively influence its bioactivity properties. In particular, the onset time for the formation of the HCA layer during glass exposure to a simulated body fluid (SBF) solution is delayed by crystallization
The regulation of financial derivates: an agent-based model approach
Get PDFIn 2007-08, the world experienced the greatest financial crisis since 1929, which turned
– in the following years – in one of the deepest and most prolonged periods of economic
stagnation of modern history. While there were multiple conditions that originated the
so-called Great Financial Crisis, a general consensus emerged that financial derivatives
played an important role in the outbreak of the crisis and in posing a credible threat that
the entire global financial system could melt down. As a reaction, several countries in
the world and international organizations agreed on a policy response to reformulate the
global architecture for the regulation of the financial system, including the financial
derivatives industry. Yet, the fundamental question of whether the contemporary system
of derivatives regulation can effectively shield the financial system from sources of
systemic risk is still undecided, for reasons that especially relate to the complexity of
the networked structure of the financial derivatives industry. As a way to contribute to
tackle this issue, this work aims to investigate whether an important component part of
the present system of financial derivatives regulation – namely, Central Counterparts
(CCPs) Clearing Houses – provide a more resilient financial system. The research
question is addressed through a simulation approach based on an agent-based modeling
of the financial derivatives industry. The results of the simulation show that the
introduction of a CCP improves the resilience of the simulated financial derivatives
industry, although it does not completely shield the financial system from disruptions
that may especially depend from the degree of interconnectedness of financial operators
and the magnitude of defaults. In sum, this work offers some methodological guidance
for enriching the repertoire of tools at disposal of financial regulatory authorities in
anticipating the consequences of interventions in the financial industry
Giurisprudenza della Corte di Giustizia e Amministrazione nazionale: poteri, doveri e spunti per un’analisi comparata
Get PDFNowadays, a huge judicial phenomenon involves European Countries: the crisis of law. In particular, written law, as acts and regulaments, are losing importance, while case law and jugdements are enhancing their influence.
Most of times, the domestic law of European countries is influnced by E.U. Court of Justice’s judgements.
The European Court of Justice is very different from other courts, both domestic and international. Her original main role focused on uniform intepretation of European law.
This function may be related just to intepretation of rules. But, sometimes, the Court also create rules and principles, that became self-executive in Member States.
The Court of Justice, also, organised a “nomofilachia network” (as some Authors used to say), in which national courts and Public Administration provide to guarantee the uniform intepretation and application of E.U. case law.
Referring to Public Administrations, three types of competences can be clearly seen: the administrative re-examination of an anti-comunitarian decision, the positive execution of European judgements (that, many times, provide to extend citizens’ rights), the competence that involve the principle of precaution.
The question is: has the European Court of Justice an administrative role? Is her function internal or only international?
The thesis is completed by a brief comparate analysis about Court of Justice’s role in a common law Country and a civil law Country: United Kingdom and Spain
Profili evolutivi del diritto degli appalti. Il paradigma delle cause di esclusione
Get PDFItalian administrative law has been undergoing an evolution aimed at progressively eliminating the relevance
that merely formal defects have traditionally held, an evolution which has nonetheless struggled to gain
prominence in the case of the procedures for obtaining public commissions. In this regard, the aim of
safeguarding the fundamental right to equality of treatment has been pursued by means of merely formal
rules, whose strict compliance has always been regarded as indispensable for the accomplishment of the
afore mentioned aim. The necessity of going beyond the former legal set-up in order to fully guarantee the
principle of “favor partecipationis” has gained prominence with some difficulty and solely recently. This
doctoral thesis, by analyzing the field of exclusions from public tenders, aims to illustrate how the evolution
of national tender law has been taking place at the material level, and to show to what extent the
phenomenon of the so-called hybridization of the Italian legal system under the influence of European law
has actually affected this very evolution itself
Il "berretto dell’operaio" e il "cappello dell'ingegnere" Organizzazione del lavoro, direzioni aziendali e operai di mestiere nei cantieri navali di Brema
Get PDFThe research intends to offer the perspective of an organic study of the history of production, union trades and society in River Weser shipyards, which raised and developed around the city of Bremen. The selected time span is the decade going from the outbreak of World War I and the ultimate post-inflationary stabilization in 1924. Five thematic issues are taken into consideration in order to analyse the development of productive forces, and the forms of worksmen subjectivity and of labour conflicts: the reinforcement of management executives as a direction organ in work socialization; factory discipline as an instrument for the conformance of workers behaviour to the demands of the production process; razionalization, meaning a process of transformation of professions and crafts and of the connection between planning and realization; the form and structure of salary, considered in a double perspective, as job payment and as the primary matter of contention in factory conflicts. The fifth point concerns the forms of organization of the labour movement. In an attempt to analyse the formation of workers' councils and the practices of conflict, in strong and constant relation with the previous thematic issues, the dissertation tries to shed light on both the continuity of organizational forms, due to craftsmen's perduring centrality, and the emergence, especially in the vision of workers' councils, of stances concerning workers' control on production
Da luogo a logo. Trasformazioni dell’identità visiva in Sardegna
Get PDFThe work explores the interactions between places and visual identities: from heraldry to the flags , to the trademarks and
logos of today's" destinations" , the term which are marked the places considered as tourist targets. The logo - the icon by
which a power asserts its authority - is an ambivalent element : it needs to be strong and repeateble, but its synthesis is
intrinsically adaptive. An object of modernity, that always more frequently, in a world that points to homogeneisation, is
not the result but the first constituent of an identity - not only cultural, but even physical, architectural , geographical -
increasingly weak. Following a discussion on international practices , the work focuses on Sardinia, a sensitive territory
where sensitive history and modernity meet, often with a critical outcoming. In this context some projects having the
communication of the places on the island are presented