EoR in alternative cosmological scenarios

The aim of this Thesis is to investigate the possibility that the observations related to the epoch of reionization can probe not only the evolution of the IGM state, but also the cosmological background in which this process occurs. In fact, the history of the IGM ionization is indeed affected by the evolution of the sources of ionizing photons that, under the assumption of a structure formation paradigm determined by the hierarchic growth of the matter uctuations, results strongly dependent on the characteristics of the background universe. For the purpose of our investigation, we have analysed the reionization history in innovative cosmological frameworks, still in agreement with the recent observational tests related to the SNIa and the CMB probes, comparing our results with the reionization scenario predicted by the commonly used LCDM cosmology. In particular, in this Thesis we have considered two different alternative universes. The first one is a at universe dominated at late epochs by a dynamic dark energy component, characterized by an equation of state evolving in time. The second cosmological framework we have assumed is a LCDM characterized by a primordial overdensity field having a non-Gaussian probability distribution. The reionization scenario have been investigated, in this Thesis, through semi-analytic approaches based on the hierarichic growth of the matter uctuations and on suitable assumptions concerning the ionization and the recombination of the IGM. We make predictions for the evolution and the distribution of the HII regions, and for the global features of reionization, that can be constrained by future observations. Finally, we brie y discuss the possible future prospects of this Thesis work.

Design of alternative energy storage systems for hybrid vehicles based on statistical processing of driving cycles information

Hybrid vehicles represent the future for automakers, since they allow to improve the fuel economy and to reduce the pollutant emissions. A key component of the hybrid powertrain is the Energy Storage System, that determines the ability of the vehicle to store and reuse energy. Though electrified Energy Storage Systems (ESS), based on batteries and ultracapacitors, are a proven technology, Alternative Energy Storage Systems (AESS), based on mechanical, hydraulic and pneumatic devices, are gaining interest because they give the possibility of realizing low-cost mild-hybrid vehicles. Currently, most literature of design methodologies focuses on electric ESS, which are not suitable for AESS design. In this contest, The Ohio State University has developed an Alternative Energy Storage System design methodology. This work focuses on the development of driving cycle analysis methodology that is a key component of Alternative Energy Storage System design procedure. The proposed methodology is based on a statistical approach to analyzing driving schedules that represent the vehicle typical use. Driving data are broken up into power events sequence, namely traction and braking events, and for each of them, energy-related and dynamic metrics are calculated. By means of a clustering process and statistical synthesis methods, statistically-relevant metrics are determined. These metrics define cycle representative braking events. By using these events as inputs for the Alternative Energy Storage System design methodology, different system designs are obtained. Each of them is characterized by attributes, namely system volume and weight. In the last part the work, the designs are evaluated in simulation by introducing and calculating a metric related to the energy conversion efficiency. Finally, the designs are compared accounting for attributes and efficiency values. In order to automate the driving data extraction and synthesis process, a specific script Matlab based has been developed. Results show that the driving cycle analysis methodology, based on the statistical approach, allows to extract and synthesize cycle representative data. The designs based on cycle statistically-relevant metrics are properly sized and have satisfying efficiency values with respect to the expectations. An exception is the design based on the cycle worst-case scenario, corresponding to same approach adopted by the conventional electric ESS design methodologies. In this case, a heavy system with poor efficiency is produced. The proposed new methodology seems to be a valid and consistent support for Alternative Energy Storage System design.

The use of Ground Penetrating Radar and alternative geophysical techniques for assessing embankments and dykes safety

The research is part of a survey for the detection of the hydraulic and geotechnical conditions of river embankments funded by the Reno River Basin Regional Technical Service of the Region Emilia-Romagna. The hydraulic safety of the Reno River, one of the main rivers in North-Eastern Italy, is indeed of primary importance to the Emilia-Romagna regional administration. The large longitudinal extent of the banks (several hundreds of kilometres) has placed great interest in non-destructive geophysical methods, which, compared to other methods such as drilling, allow for the faster and often less expensive acquisition of high-resolution data. The present work aims to experience the Ground Penetrating Radar (GPR) for the detection of local non-homogeneities (mainly stratigraphic contacts, cavities and conduits) inside the Reno River and its tributaries embankments, taking into account supplementary data collected with traditional destructive tests (boreholes, cone penetration tests etc.). A comparison with non-destructive methodologies likewise electric resistivity tomography (ERT), Multi-channels Analysis of Surface Waves (MASW), FDEM induction, was also carried out in order to verify the usability of GPR and to provide integration of various geophysical methods in the process of regular maintenance and check of the embankments condition. The first part of this thesis is dedicated to the explanation of the state of art concerning the geographic, geomorphologic and geotechnical characteristics of Reno River and its tributaries embankments, as well as the description of some geophysical applications provided on embankments belonging to European and North-American Rivers, which were used as bibliographic basis for this thesis realisation. The second part is an overview of the geophysical methods that were employed for this research, (with a particular attention to the GPR), reporting also their theoretical basis and a deepening of some techniques of the geophysical data analysis and representation, when applied to river embankments. The successive chapters, following the main scope of this research that is to highlight advantages and drawbacks in the use of Ground Penetrating Radar applied to Reno River and its tributaries embankments, show the results obtained analyzing different cases that could yield the formation of weakness zones, which successively lead to the embankment failure. As advantages, a considerable velocity of acquisition and a spatial resolution of the obtained data, incomparable with respect to other methodologies, were recorded. With regard to the drawbacks, some factors, related to the attenuation losses of wave propagation, due to different content in clay, silt, and sand, as well as surface effects have significantly limited the correlation between GPR profiles and geotechnical information and therefore compromised the embankment safety assessment. Recapitulating, the Ground Penetrating Radar could represent a suitable tool for checking up river dike conditions, but its use has significantly limited by geometric and geotechnical characteristics of the Reno River and its tributaries levees. As a matter of facts, only the shallower part of the embankment was investigate, achieving also information just related to changes in electrical properties, without any numerical measurement. Furthermore, GPR application is ineffective for a preliminary assessment of embankment safety conditions, while for detailed campaigns at shallow depth, which aims to achieve immediate results with optimal precision, its usage is totally recommended. The cases where multidisciplinary approach was tested, reveal an optimal interconnection of the various geophysical methodologies employed, producing qualitative results concerning the preliminary phase (FDEM), assuring quantitative and high confidential description of the subsoil (ERT) and finally, providing fast and highly detailed analysis (GPR). Trying to furnish some recommendations for future researches, the simultaneous exploitation of many geophysical devices to assess safety conditions of river embankments is absolutely suggested, especially to face reliable flood event, when the entire extension of the embankments themselves must be investigated.

Indagine sul meccanismo di stiratura semipermanente del capello per la ricerca di alternative all'uso di aldeide formica

La scarsità di informazioni sulle reazioni che intervengono nel processo di stiratura semipermanente dei capelli e la necessità di trovare prodotti alternativi all’uso della formaldeide ha portato a intraprendere questo lavoro di tesi. Esso si è svolto seguendo due linee principali: l’indagine sui possibili meccanismi di reazione che intervengono fra composti aventi gruppi aldeidici, quali formaldeide o acido gliossilico (particolarmente efficaci nel processo di stiratura), e alcuni amminoacidi presenti nei capelli da un lato, e uno studio sulle modificazioni che intervengono nella fibra attraverso spettroscopia Raman e ATR-FT-IR e microscopia elettronica a scansione (SEM) dall’altro. Partendo dall’ipotesi più plausibile di una addizione sull’atomo di carbonio carbonilico da parte di nucleofili presenti su alcuni residui amminoacidici della catena polipeptidica, sono stati presi in considerazioni tre gruppi funzionali presenti sugli amminoacidi che possono dar luogo ad addizione reversibile al carbonio carbonilico: il gruppo tiolico che comportandosi come nucleofilo allo zolfo potrebbe dare formazione di semitioacetali, il gruppo ossidrilico di amminoacidi come serina e treonina che potrebbe dare semiacetali, ed il gruppo amminico di amminoacidi basici che agendo da nucleofilo all’azoto potrebbe generare immine. Dopo aver indagato sulla reazione fra aldeide formica (o acido gliossilico) con cisteina e derivati, l’indagine è proseguita utilizzando come amminoacido basico modello N-acetil-L-lisina, dove il gruppo amminico in posizione alfa al carbossile è protetto per cercare di mimare la situazione nel polipeptide. Alcune prove sono state condotte facendo reagire questo substrato sia con una serie di aldeidi aromatiche in diverse condizioni sperimentali che con acido gliossilico. In seguito sono state svolte analisi mediante spettroscopia Raman e ATR-FT-IR su ciocche di pelo di yak nelle diverse fasi del trattamento più comunemente utilizzato nella stiratura semipermanente. Questo ha permesso di ottenere indicazioni sia sulle modificazioni della struttura secondaria subite dalla fibra che sul verificarsi di reazioni fra agente lisciante e residui amminoacidici presenti su di essa. Infine è stata svolta un’indagine SEM sia su fibre di yak che su capelli umani ricci per osservare le variazioni superficiali nei diversi stadi del trattamento.

Sustainable inorganic Binders and Their Applications in Building Engineering: A Green Alternative to Ordinary Portland Cement

In the last decades, the building materials and construction industry has been contributing to a great extent to generate a high impact on our environment. As it has been considered one of the key areas in which to operate to significantly reduce our footprint on environment, there has been widespread belief that particular attention now has to be paid and specific measures have to be taken to limit the use of non-renewable resources.The aim of this thesis is therefore to study and evaluate sustainable alternatives to commonly used building materials, mainly based on ordinary Portland Cement, and find a supportable path to reduce CO2 emissions and promote the re-use of waste materials. More specifically, this research explores different solutions for replacing cementitious binders in distinct application fields, particularly where special and more restricting requirements are needed, such as restoration and conservation of architectural heritage. Emphasis was thus placed on aspects and implications more closely related to the concept of non-invasivity and environmental sustainability. A first part of the research was addressed to the study and development of sustainable inorganic matrices, based on lime putty, for the pre-impregnation and on-site binding of continuous carbon fiber fabrics for structural rehabilitation and heritage restoration. Moreover, with the aim to further limit the exploitation of non-renewable resources, the synthesis of chemically activated silico-aluminate materials, as metakaolin, ladle slag or fly ash, was thus successfully achieved. New sustainable binders were hence proposed as novel building materials, suitable to be used as primary component for construction and repair mortars, as bulk materials in high-temperature applications or as matrices for high-toughness fiber reinforced composites.

Comparative Analysis of Alternative Hybrid Systems for Automotive Applications

The main objective of this work was to investigate the impact of different hybridization concepts and levels of hybridization on fuel economy of a standard road vehicle where both conventional and non-conventional hybrid architectures are treated exactly in the same way from the point of view of overall energy flow optimization. Hybrid component models were developed and presented in detail as well as the simulations results mainly for NEDC cycle. The analysis was performed on four different parallel hybrid powertrain concepts: Hybrid Electric Vehicle (HEV), High Speed Flywheel Hybrid Vehicle (HSF-HV), Hydraulic Hybrid Vehicle (HHV) and Pneumatic Hybrid Vehicle (PHV). In order to perform equitable analysis of different hybrid systems, comparison was performed also on the basis of the same usable system energy storage capacity (i.e. 625kJ for HEV, HSF and the HHV) but in the case of pneumatic hybrid systems maximal storage capacity was limited by the size of the systems in order to comply with the packaging requirements of the vehicle. The simulations were performed within the IAV Gmbh - VeLoDyn software simulator based on Matlab / Simulink software package. Advanced cycle independent control strategy (ECMS) was implemented into the hybrid supervisory control unit in order to solve power management problem for all hybrid powertrain solutions. In order to maintain State of Charge within desired boundaries during different cycles and to facilitate easy implementation and recalibration of the control strategy for very different hybrid systems, Charge Sustaining Algorithm was added into the ECMS framework. Also, a Variable Shift Pattern VSP-ECMS algorithm was proposed as an extension of ECMS capabilities so as to include gear selection into the determination of minimal (energy) cost function of the hybrid system. Further, cycle-based energetic analysis was performed in all the simulated cases, and the results have been reported in the corresponding chapters.

An alternative blocking layer for titanium dioxide (TiO 2) solar cell applications

In hybrid organic solar cells a blocking layer between transparent electrode and nanocrystalline titania particles is essential to prevent short-circuiting and current loss through recombination at the electrode interface. Here the preparation of a uniform hybrid blocking layer which is composed of conducting titania nanoparticles embedded in an insulating polymer derived ceramic is presented. This blocking layer is prepared by sol-gel chemistry where an amphiphilic block copolymer is used as a templating agent. A novel poly(dimethylsiloxane) containing amphiphilic block copolymer poly(ethyleneglycol)methylethermethacrylate-block-poly(dimethylsiloxane)-block-poly(ethyleneglycol)methylethermethacrylate has been synthesized to act as the templating agent. Plasma treatment uncovered titania surface from any polymer. Annealing at 450°C under nitrogen resulted in anatase titania with polymer derived silicon oxycarbide ceramic. Electrical characterization by conductive scanning probe microscopy experiments revealed a percolating titania network separated by an insulating ceramic matrix. Scanning Kelvin probe force microscopy showed predominant presence of titania particles on the surface creating a large surface area for dye absorption. The uniformity of the percolating structures was proven by microbeam grazing incidence small angle x-ray scattering. First applications in hybrid organic solar cells in comparison with conventional titanium dioxide blocking layer containing devices revealed 15 fold increases in corresponding efficiencies. Poly(dimethylsiloxane)-block-poly(ethyleneglycol)methylethermethacrylate and poly(ethyleneoxide)-poly(dimethylsiloxane)methylmethacrylate diblock copolymers were also synthesized. Their titania nanocomposite films were compared with the integrated blocking layer. Liner poly(ethyleneoxide) containing diblock copolymer resulted in highly ordered foam like structures. The effect of heating temperature rise to 600°C and 1000°C on titania morphology was investigated by scanning electron and force microscopy and x-ray scattering. Sol-gel contents, hydrochloric acid, titania precursor and amphiphilic triblock copolymer were altered to see their effect on titania morphology. Increase in block copolymer content resulted in titania particles of diameter 15-20 nm.

Valutazione della sostenibilità ambientale tramite metodologia LCA di sistemi per lo sfruttamento di fonti alternative di energia e materiali

La dissertazione ha riguardato l’analisi di sostenibilità di un sistema agronomico per la produzione di olio vegetale a fini energetici in terreni resi marginali dall’infestazione di nematodi. Il processo indagato ha previsto il sovescio di una coltura con proprietà biofumiganti (brassicacea) coltivata in precessione alla specie oleosa (soia e tabacco) al fine di contrastare il proliferare dell’infestazione nel terreno. Tale sistema agronomico è stato confrontato attraverso una analisi di ciclo di vita (LCA) ad uno scenario di coltivazione della stessa specie oleosa senza precessione di brassica ma con l’utilizzo di 1-3-dicloropropene come sistema di lotta ai nematodi. Allo scopo di completare l’analisi LCA con una valutazione dell’impatto sull’uso del suolo (Land use Impact) generato dai due scenari a confronto, sono stati costruiti due modelli nel software per il calcolo del Soil Conditioning Index (SCI), un indicatore quali-quantitativo della qualità del terreno definito dal Dipartimento per l’Agricoltura degli Stati Uniti d’America (USDA).

Analisi del ciclo di vita della produzione industriale di acroleina: confronto tra il processo tradizionale e vie di sintesi alternative.

La green chemistry può essere definita come l’applicazione dei principi fondamentali di sviluppo sostenibile, al fine di ridurre al minimo l’impiego o la formazione di sostanze pericolose nella progettazione, produzione e applicazione di prodotti chimici. È in questo contesto che si inserisce la metodologia LCA (Life Cycle Assessment), come strumento di analisi e di valutazione. Il presente lavoro di tesi è stato condotto con l’intenzione di offrire una valutazione degli impatti ambientali associati al settore dei processi chimici di interesse industriale in una prospettiva di ciclo di vita. In particolare, è stato studiato il processo di produzione di acroleina ponendo a confronto due vie di sintesi alternative: la via tradizionale che impiega propilene come materia prima, e l’alternativa da glicerolo ottenuto come sottoprodotto rinnovabile di processi industriali. Il lavoro si articola in due livelli di studio: un primo, parziale, in cui si va ad esaminare esclusivamente il processo di produzione di acroleina, non considerando gli stadi a monte per l’ottenimento delle materie prime di partenza; un secondo, più dettagliato, in cui i confini di sistema vengono ampliati all’intero ciclo produttivo. I risultati sono stati confrontati ed interpretati attraverso tre tipologie di analisi: Valutazione del danno, Analisi di contributo ed Analisi di incertezza. Dal confronto tra i due scenari parziali di produzione di acroleina, emerge come il processo da glicerolo abbia impatti globalmente maggiori rispetto al tradizionale. Tale andamento è ascrivibile ai diversi consumi energetici ed in massa del processo per l’ottenimento dell’acroleina. Successivamente, per avere una visione completa di ciascuno scenario, l’analisi è stata estesa includendo le fasi a monte di produzione delle due materie prime. Da tale confronto emerge come lo scenario più impattante risulta essere quello di produzione di acroleina partendo da glicerolo ottenuto dalla trans-esterificazione di olio di colza. Al contrario, lo scenario che impiega glicerolo prodotto come scarto della lavorazione di sego sembra essere il modello con i maggiori vantaggi ambientali. Con l’obiettivo di individuare le fasi di processo maggiormente incidenti sul carico totale e quindi sulle varie categorie d’impatto intermedie, è stata eseguita un’analisi di contributo suddividendo ciascuno scenario nei sotto-processi che lo compongono. È stata infine eseguita un’analisi di incertezza tramite il metodo Monte Carlo, verificando la riproducibilità dei risultati.

A Law and Economics Analysis of Trade Secrets: Optimal Scope of Law, Misappropriation and Alternative Damages Regimes

This thesis is primarily based on three core chapters, focused on the fundamental issues of trade secrets law. The goal of this thesis is to come up with policy recommendations to improve legal structure governing trade secrets. The focal points of this research are the following. What is the optimal scope of trade secrets law? How does it depend on the market characteristics such as degree of product differentiation between competing products? What factors need to be considered to balance the contradicting objectives of promoting innovation and knowledge diffusion? The second strand of this research focuses on the desirability of lost profits or unjust enrichment damage regimes in case of misappropriation of a trade secret. A comparison between these regimes is made and simple policy implications are extracted from the analysis. The last part of this research is an empirical analysis of a possible relationship between trade secrets sharing and misappropriation instances faced by firms.

Alternative reproductive tactics, sexual selection and the effects of inbreeding in the ant Hypoponera opacior

Inbreeding can lead to a fitness reduction due to the unmasking of deleterious recessive alleles and the loss of heterosis. Therefore, most sexually reproducing organisms avoid inbreeding, often by disperal. Besides the avoidance of inbreeding, dispersal lowers intraspecific competition on a local scale and leads to a spreading of genotypes into new habitats. In social insects, winged reproductives disperse and mate during nuptial flights. Therafter, queens independently found a new colony. However, some species also produce wingless sexuals as an alternative reproductive tactic. Wingless sexuals mate within or close to their colony and queens either stay in the nest or they found a new colony by budding. During this dependent colony foundation, wingless queens are accompanied by a fraction of nestmate workers. The production of wingless reproductives therefore circumvents the risks associated with dispersal and independent colony foundation. However, the absence of dispersal can lead to inbreeding and local competition.rnIn my PhD-project, I investigated the mating biology of Hypoponera opacior, an ant that produces winged and wingless reproductives in a population in Arizona. Besides the investigation of the annual reproductive cycle, I particularly focused on the consequences of wingless reproduction. An analysis of sex ratios in wingless sexuals should reveal the relative importance of local resource competition among queens (that mainly compete for the help of workers) and local mate competition among males. Further, sexual selection was expected to act on wingless males that were previously found to mate with and mate-guard pupal queens in response to local mate competition. We studied whether males are able to adapt their mating behaviour to the current competitive situation in the nest and which traits are under selection in this mating situation. Last, we investigated the extent and effects of inbreeding. As the species appeared to produce non-dispersive males and queens quite frequently, we assumed to find no or only weak negative effects of inbreeding and potentially mechanisms that moderate inbreeding levels despite frequent nest-matings.rnWe found that winged and wingless males and queens are produced during two separate seasons of the year. Winged sexuals emerge in early summer and conduct nuptial flights in July, when climate conditions due to frequent rainfalls lower the risks of dispersal and independent colony foundation. In fall, wingless sexuals are produced that reproduce within the colonies leading to an expansion on the local scale. The absence of dispersal during this second reproductive season resulted in a local genetic population viscosity and high levels of inbreeding within the colonies. Male-biased sex ratios in fall indicated a greater importance of local resource competition among queens than local mate competition among males. Males were observed to adjust mate-guarding durations to the competitive situation (i.e. the number of competing males and pupae) in the nest, an adaptation that helps maximising their reproductive success. Further, sexual selection was found to act on the timing of emergence as well as on body size in these males, i.e. earlier emerging and larger males show a higher mating success. Genetic analyses revealed that wingless males do not actively avoid inbreeding by choosing less related queens as mating partners. Further, we detected diploid males, a male type that is produced instead of diploid females if close relatives mate. In contrast to many other Hymenopteran species, diploid males were here viable and able to sire sterile triploid offspring. They did not differ in lifespan, body size and mating success from “normal” haploid males. Hence, diploid male production in H. opacior is less costly than in other social Hymenopteran species. No evidence of inbreeding depression was found on the colony level but more inbred colonies invested more resources into the production of sexuals. This effect was more pronounced in the dispersive summer generation. The increased investment in outbreeding sexuals can be regarded as an active strategy to moderate the extent and effects of inbreeding. rnIn summary, my thesis describes an ant species that has evolved alternative reproductive tactics as an adaptation to seasonal environmental variations. Hereby, the species is able to maintain its adaptive mating system without suffering from negative effects due to the absence of dispersal flights in fall.rn

Cost-Effectiveness of Alternative Retrofit Options to Support Decision Making

How to evaluate the cost-effectiveness of repair/retrofit intervention vs. demolition/replacement and what level of shaking intensity can the chosen repairing/retrofit technique sustain are open questions affecting either the pre-earthquake prevention, the post-earthquake emergency and the reconstruction phases. The (mis)conception that the cost of retrofit interventions would increase linearly with the achieved seismic performance (%NBS) often discourages stakeholders to consider repair/retrofit options in a post-earthquake damage situation. Similarly, in a pre-earthquake phase, the minimum (by-law) level of %NBS might be targeted, leading in some cases to no-action. Furthermore, the performance measure enforcing owners to take action, the %NBS, is generally evaluated deterministically. Not directly reflecting epistemic and aleatory uncertainties, the assessment can result in misleading confidence on the expected performance. The present study aims at contributing to the delicate decision-making process of repair/retrofit vs. demolition/replacement, by developing a framework to assist stakeholders with the evaluation of the effects in terms of long-term losses and benefits of an increment in their initial investment (targeted retrofit level) and highlighting the uncertainties hidden behind a deterministic approach. For a pre-1970 case study building, different retrofit solutions are considered, targeting different levels of %NBS, and the actual probability of reaching Collapse when considering a suite of ground-motions is evaluated, providing a correlation between %NBS and Risk. Both a simplified and a probabilistic loss modelling are then undertaken to study the relationship between %NBS and expected direct and indirect losses.