13 resultados para Heavy duty vehicles

em AMS Tesi di Dottorato - Alm@DL - Università di Bologna


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In pursuit of aligning with the European Union's ambitious target of achieving a carbon-neutral economy by 2050, researchers, vehicle manufacturers, and original equipment manufacturers have been at the forefront of exploring cutting-edge technologies for internal combustion engines. The introduction of these technologies has significantly increased the effort required to calibrate the models implemented in the engine control units. Consequently the development of tools that reduce costs and the time required during the experimental phases, has become imperative. Additionally, to comply with ever-stricter limits on 〖"CO" 〗_"2" emissions, it is crucial to develop advanced control systems that enhance traditional engine management systems in order to reduce fuel consumption. Furthermore, the introduction of new homologation cycles, such as the real driving emissions cycle, compels manufacturers to bridge the gap between engine operation in laboratory tests and real-world conditions. Within this context, this thesis showcases the performance and cost benefits achievable through the implementation of an auto-adaptive closed-loop control system, leveraging in-cylinder pressure sensors in a heavy-duty diesel engine designed for mining applications. Additionally, the thesis explores the promising prospect of real-time self-adaptive machine learning models, particularly neural networks, to develop an automatic system, using in-cylinder pressure sensors for the precise calibration of the target combustion phase and optimal spark advance in a spark-ignition engines. To facilitate the application of these combustion process feedback-based algorithms in production applications, the thesis discusses the results obtained from the development of a cost-effective sensor for indirect cylinder pressure measurement. Finally, to ensure the quality control of the proposed affordable sensor, the thesis provides a comprehensive account of the design and validation process for a piezoelectric washer test system.

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Nowadays, the spreading of the air pollution crisis enhanced by greenhouse gases emission is leading to the worsening of global warming. Recently, several metropolitan cities introduced Zero-Emissions Zones where the use of the Internal Combustion Engine is forbidden to reduce localized pollutants emissions. This is particularly problematic for Plug-in Hybrid Electric Vehicles, which usually work in depleting mode. In order to address these issues, the present thesis presents a viable solution by exploiting vehicular connectivity to retrieve navigation data of the urban event along a selected route. The battery energy needed, in the form of a minimum State of Charge (SoC), is calculated by a Speed Profile Prediction algorithm and a Backward Vehicle Model. That value is then fed to both a Rule-Based Strategy, developed specifically for this application, and an Adaptive Equivalent Consumption Minimization Strategy (A-ECMS). The effectiveness of this approach has been tested with a Connected Hardware-in-the-Loop (C-HiL) on a driving cycle measured on-road, stimulating the predictions with multiple re-routings. However, even if hybrid electric vehicles have been recognized as a valid solution in response to increasingly tight regulations, the reduced engine load and the repeated engine starts and stops may reduce substantially the temperature of the exhaust after-treatment system (EATS), leading to relevant issues related to pollutant emission control. In this context, electrically heated catalysts (EHCs) represent a promising solution to ensure high pollutant conversion efficiency without affecting engine efficiency and performance. This work aims at studying the advantages provided by the introduction of a predictive EHC control function for a light-duty Diesel plug-in hybrid electric vehicle (PHEV) equipped with a Euro 7-oriented EATS. Based on the knowledge of future driving scenarios provided by vehicular connectivity, engine first start can be predicted and therefore an EATS pre-heating phase can be planned.

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One of the problems in the analysis of nucleus-nucleus collisions is to get information on the value of the impact parameter b. This work consists in the application of pattern recognition techniques aimed at associating values of b to groups of events. To this end, a support vec- tor machine (SVM) classifier is adopted to analyze multifragmentation reactions. This method allows to backtracing the values of b through a particular multidimensional analysis. The SVM classification con- sists of two main phase. In the first one, known as training phase, the classifier learns to discriminate the events that are generated by two different model:Classical Molecular Dynamics (CMD) and Heavy- Ion Phase-Space Exploration (HIPSE) for the reaction: 58Ni +48 Ca at 25 AMeV. To check the classification of events in the second one, known as test phase, what has been learned is tested on new events generated by the same models. These new results have been com- pared to the ones obtained through others techniques of backtracing the impact parameter. Our tests show that, following this approach, the central collisions and peripheral collisions, for the CMD events, are always better classified with respect to the classification by the others techniques of backtracing. We have finally performed the SVM classification on the experimental data measured by NUCL-EX col- laboration with CHIMERA apparatus for the previous reaction.

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The present work tries to display a comprehensive and comparative study of the different legal and regulatory problems involved in international securitization transactions. First, an introduction to securitization is provided, with the basic elements of the transaction, followed by the different varieties of it, including dynamic securitization and synthetic securitization structures. Together with this introduction to the intricacies of the structure, a insight into the influence of securitization in the financial and economic crisis of 2007-2009 is provided too; as well as an overview of the process of regulatory competition and cooperation that constitutes the framework for the international aspects of securitization. The next Chapter focuses on the aspects that constitute the foundations of structured finance: the inception of the vehicle, and the transfer of risks associated to the securitized assets, with particular emphasis on the validity of those elements, and how a securitization transaction could be threatened at its root. In this sense, special importance is given to the validity of the trust as an instrument of finance, to the assignment of future receivables or receivables in block, and to the importance of formalities for the validity of corporations, trusts, assignments, etc., and the interaction of such formalities contained in general corporate, trust and assignment law with those contemplated under specific securitization regulations. Then, the next Chapter (III) focuses on creditor protection aspects. As such, we provide some insights on the debate on the capital structure of the firm, and its inadequacy to assess the financial soundness problems inherent to securitization. Then, we proceed to analyze the importance of rules on creditor protection in the context of securitization. The corollary is in the rules in case of insolvency. In this sense, we divide the cases where a party involved in the transaction goes bankrupt, from those where the transaction itself collapses. Finally, we focus on the scenario where a substance over form analysis may compromise some of the elements of the structure (notably the limited liability of the sponsor, and/or the transfer of assets) by means of veil piercing, substantive consolidation, or recharacterization theories. Once these elements have been covered, the next Chapters focus on the regulatory aspects involved in the transaction. Chapter IV is more referred to “market” regulations, i.e. those concerned with information disclosure and other rules (appointment of the indenture trustee, and elaboration of a rating by a rating agency) concerning the offering of asset-backed securities to the public. Chapter V, on the other hand, focuses on “prudential” regulation of the entity entrusted with securitizing assets (the so-called Special Purpose vehicle), and other entities involved in the process. Regarding the SPV, a reference is made to licensing requirements, restriction of activities and governance structures to prevent abuses. Regarding the sponsor of the transaction, a focus is made on provisions on sound originating practices, and the servicing function. Finally, we study accounting and banking regulations, including the Basel I and Basel II Frameworks, which determine the consolidation of the SPV, and the de-recognition of the securitized asset from the originating company’s balance-sheet, as well as the posterior treatment of those assets, in particular by banks. Chapters VI-IX are concerned with liability matters. Chapter VI is an introduction to the different sources of liability. Chapter VII focuses on the liability by the SPV and its management for the information supplied to investors, the management of the asset pool, and the breach of loyalty (or fiduciary) duties. Chapter VIII rather refers to the liability of the originator as a result of such information and statements, but also as a result of inadequate and reckless originating or servicing practices. Chapter IX finally focuses on third parties entrusted with the soundness of the transaction towards the market, the so-called gatekeepers. In this respect, we make special emphasis on the liability of indenture trustees, underwriters and rating agencies. Chapters X and XI focus on the international aspects of securitization. Chapter X contains a conflicts of laws analysis of the different aspects of structured finance. In this respect, a study is made of the laws applicable to the vehicle, to the transfer of risks (either by assignment or by means of derivatives contracts), to liability issues; and a study is also made of the competent jurisdiction (and applicable law) in bankruptcy cases; as well as in cases where a substance-over-form is performed. Then, special attention is also devoted to the role of financial and securities regulations; as well as to their territorial limits, and extraterritoriality problems involved. Chapter XI supplements the prior Chapter, for it analyzes the limits to the States’ exercise of regulatory power by the personal and “market” freedoms included in the US Constitution or the EU Treaties. A reference is also made to the (still insufficient) rules from the WTO Framework, and their significance to the States’ recognition and regulation of securitization transactions.

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The cathepsin enzymes represent an important family of lysosomal proteinases with a broad spectrum of functions in many, if not in all, tissues and cell types. In addition to their primary role during the normal protein turnover, they possess highly specific proteolytic activities, including antigen processing in the immune response and a direct role in the development of obesity and tumours. In pigs, the involvement of cathepsin enzymes in proteolytic processes have important effects during the conversion of muscle to meat, due to their influence on meat texture and sensory characteristics, mainly in seasoned products. Their contribution is fundamental in flavour development of dry-curing hams. However, several authors have demonstrated that high cathepsin activity, in particular of cathepsin B, is correlated to defects of these products, such as an excessive meat softness together with abnormal free tyrosine content, astringent or metallic aftertastes and formation of a white film on the cut surface. Thus, investigation of their genetic variability could be useful to identify DNA markers associated with these dry cured hams parameters, but also with meat quality, production and carcass traits in Italian heavy pigs. Unfortunately, no association has been found between cathepsin markers and meat quality traits so far, in particular with cathepsin B activity, suggesting that other genes, besides these, affect meat quality parameters. Nevertheless, significant associations were observed with several carcass and production traits in pigs. A recent study has demonstrated that different single nucleotide polymorphisms (SNPs) localized in cathepsin D (CTSD), F (CTSF), H and Z genes were highly associated with growth, fat deposition and production traits in an Italian Large White pig population. The aim of this thesis was to confirm some of these results in other pig populations and identify new cathepsin markers in order to evaluate their effects on cathepsin activity and other production traits. Furthermore, starting from the data obtained in previous studies on CTSD gene, we also analyzed the known polymorphism located in the insulin-like growth factor 2 gene (IGF2 intron3-g.3072G>A). This marker is considered the causative mutation for the quantitative trait loci (QTL) affecting muscle mass and fat deposition in pigs. Since IGF2 maps very close to CTSD on porcine chromosome (SSC) 2, we wanted to clarify if the effects of the CTSD marker were due to linkage disequilibrium with the IGF2 intron3-g.3072G>A mutation or not. In the first chapter, we reported the results from these two SSC2 gene markers. First of all, we evaluated the effects of the IGF2 intron3-g.3072G>A polymorphism in the Italian Large White breed, for which no previous studies have analysed this marker. Highly significant associations were identified with all estimated breeding values for production and carcass traits (P<0.00001), while no effects were observed for meat quality traits. Instead, the IGF2 intron3-g.3072G>A mutation did not show any associations with the analyzed traits in the Italian Duroc pigs, probably due to the low level of variability at this polymorphic site for this breed. In the same Duroc pig population, significant associations were obtained for the CTSD marker for all production and carcass traits (P < 0.001), after excluding possible confounding effects of the IGF2 mutation. The effects of the CTSD g.70G>A polymorphism were also confirmed in a group of Italian Large White pigs homozygous for the IGF2 intron3-g.3072G allele G (IGF2 intron3-g.3072GG) and by haplotype analysis between the markers of the two considered genes. Taken together, all these data indicated that the IGF2 intron3-g.3072G>A mutation is not the only polymorphism affecting fatness and muscle deposition in pigs. In the second chapter, we reported the analysis of two new SNPs identified in cathepsin L (CTSL) and cathepsin S (CTSS) genes and the association results with meat quality parameters (including cathepsin B activity) and several production traits in an Italian Large White pig population. Allele frequencies of these two markers were evaluated in 7 different pig breeds. Furthermore, we mapped using a radiation hybrid panel the CTSS gene on SSC4. Association studies with several production traits, carried out in 268 Italian Large White pigs, indicated positive effects of the CTSL polymorphism on average daily gain, weight of lean cuts and backfat thickness (P<0.05). The results for these latter traits were also confirmed using a selective genotype approach in other Italian Large White pigs (P<0.01). In the 268 pig group, the CTSS polymorphism was associated with feed:gain ratio and average daily gain (P<0.05). Instead, no association was observed between the analysed markers and meat quality parameters. Finally, we wanted to verify if the positive results obtained for the cathepsin L and S markers and for other previous identified SNPs (cathepsin F, cathepsin Z and their inhibitor cystatin B) were confirmed in the Italian Duroc pig breed (third chapter). We analysed them in two groups of Duroc pigs: the first group was made of 218 performance-tested pigs not selected by any phenotypic criteria, the second group was made of 100 Italian Duroc pigs extreme and divergent for visible intermuscular fat trait. In the first group, the CTSL polymorphism was associated with weight of lean cuts (P<0.05), while suggestive associations were obtained for average daily gain and backfat thickness (P<0.10). Allele frequencies of the CTSL gene marker also differed positively among the visible intermuscular extreme tails. Instead, no positive effects were observed for the other DNA markers on the analysed traits. In conclusion, in agreement with the present data and for the biological role of these enzymes, the porcine CTSD and CTSL markers: a) may have a direct effect in the biological mechanisms involved in determining fat and lean meat content in pigs, or b) these markers could be very close to the putative functional mutation(s) present in other genes. These findings have important practical applications, in particular the CTSD and CTSL mutations could be applied in a marker assisted selection (MAS) both in the Italian Large White and Italian Duroc breeds. Marker assisted selection could also increase in efficiency by adding information from the cathepsin S genotype, but only in the Italian Large White breed.

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Poplar is considered a good candidate for phytoremediation, but its tolerance to heavy metals has not been fully investigated yet. In the present work, two different culture systems (in vitro and aeroponic/hydroponic) and two different stress tolerant clones of Populus alba (AL22 and Villafranca) were investigated for their total polyphenol and flavonoid content, individual phenolic compounds, polyamine, lipid peroxidation and hydrogen peroxide levels in response to Cu. In AL22 poplar plants cultured in vitro in the presence or absence of 50 μM Cu, total leaves polyphenol and flavonoid content was higher in treated samples than in controls but unaltered in the roots. Equally the same clone, grown under aeroponic conditions and hydroponically treated for 72 h with 100 μM Cu, displayed increased amount of polyphenols and flavonoids in the leaves, in particular chlorogenic acid and quercetin, and no differences in the roots. In exudates from treated roots total polyphenols and flavonoids, in particular catechin and epicatechin, were more abundant than in controls. Polyamine levels show an increase in conjugated putrescine (Put) and spermidine (Spd) was found. In the Villafranca clone, treated with 100 μM Cu for 6, 24 and 72 h, the pattern of polyphenol and flavonoid accumulation was the same as in AL22; in Cu-treated roots these compounds decreased compared with controls while they increased in root exudates. Free polyamine levels rose at 24 and 72 h while only conjugated Put increased at 24 h. Cu-treated Villafranca plants exhibited a higher malondialdehyde production than controls indicative of membrane lipid peroxidation and, therefore, oxidative stress. An in vitro experiment was carried to investigate the antioxidant effect of the polyamine spermidine (Spd). Exogenous Spd, supplied together with 100 μM Cu, reduced the accumulation of polyphenols and flavonoids, MDA and hydrogen peroxide induced by Cu.

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Heavy pig breeding in Italy is mainly oriented for the production of high quality processed products. Of particular importance is the dry cured ham production, which is strictly regulated and requires specific carcass characteristics correlated with green leg characteristics. Furthermore, as pigs are slaughtered at about 160 kg live weight, the Italian pig breeding sector faces severe problems of production efficiency that are related to all biological aspects linked to growth, feed conversion, fat deposition and so on. It is well known that production and carcass traits are in part genetically determined. Therefore, as a first step to understand genetic basis of traits that could have a direct or indirect impact on dry cured ham production, a candidate gene approach can be used to identify DNA markers associated with parameters of economic importance. In this thesis, we investigated three candidate genes for carcass and production traits (TRIB3, PCSK1, MUC4) in pig breeds used for dry cured ham production, using different experimental approaches in order to find molecular markers associated with these parameters.

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This book is dedicated to the Law and Economics analysis of civil liability of securities underwriters for the damage caused by material misstatements of corporate information by securities issuers. It seeks to answer a series of important questions. Who the are underwriters and what is their main role in the securities offering? Why there is a need for legal intervention in the underwriting market? What is so special about civil liability as an enforcement tool? How is civil liability used in a real world and does it really reach its goals? Finally, is there a need for a change and, if so, by what means?

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Ultra-relativistic heavy ions generate strong electromagnetic fields which offer the possibility to study γ-γ and γ-nucleus processes at the LHC in the so called ultra-peripheral collisions (UPC). The photoproduction of J/ψ vector mesons in UPC is sensitive to the gluon distribution of the interacting nuclei. In this thesis the study of coherent and incoherent J/ψ production in Pb-Pb collisions at √sNN = 2.76 TeV is described. The J/ψ has been measured via its leptonic decay in the rapidity range -0.9 < y < 0.9. The cross section for coherent and incoherent J/ψ are given. The results are compared to theoretical models for J/ψ production and the coherent cross section is found to be in good agreement with those models which include nuclear gluon shadowing consistent with EPS09 parametrization. In addition the cross section for the process γ γ→ e+e− has been measured and found to be in agreement with the STARLIGHT Monte Carlo predictions. The analysis has been published by the ALICE Collaboration in the European Physical Journal C, with one of its main plot depicted on the cover-front of the November 2013 issue.

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Hybrid vehicles (HV), comprising a conventional ICE-based powertrain and a secondary energy source, to be converted into mechanical power as well, represent a well-established alternative to substantially reduce both fuel consumption and tailpipe emissions of passenger cars. Several HV architectures are either being studied or already available on market, e.g. Mechanical, Electric, Hydraulic and Pneumatic Hybrid Vehicles. Among the others, Electric (HEV) and Mechanical (HSF-HV) parallel Hybrid configurations are examined throughout this Thesis. To fully exploit the HVs potential, an optimal choice of the hybrid components to be installed must be properly designed, while an effective Supervisory Control must be adopted to coordinate the way the different power sources are managed and how they interact. Real-time controllers can be derived starting from the obtained optimal benchmark results. However, the application of these powerful instruments require a simplified and yet reliable and accurate model of the hybrid vehicle system. This can be a complex task, especially when the complexity of the system grows, i.e. a HSF-HV system assessed in this Thesis. The first task of the following dissertation is to establish the optimal modeling approach for an innovative and promising mechanical hybrid vehicle architecture. It will be shown how the chosen modeling paradigm can affect the goodness and the amount of computational effort of the solution, using an optimization technique based on Dynamic Programming. The second goal concerns the control of pollutant emissions in a parallel Diesel-HEV. The emissions level obtained under real world driving conditions is substantially higher than the usual result obtained in a homologation cycle. For this reason, an on-line control strategy capable of guaranteeing the respect of the desired emissions level, while minimizing fuel consumption and avoiding excessive battery depletion is the target of the corresponding section of the Thesis.