Ravenna dall' anno 1500 sino all' anno 1513,

Discorso di Jacopo Landoni, accademico pisaurico, tenuto nell' adunanza di quell' accademia 15 agosto 1826, pp. 113-128.

La comedia di Dante Allighieri /

Added t.-p., engr., dated 1840.

Actii Sinceri Sannazarii Neopolitani De partu virginis libri iii. ; with an introduction, brief account of the poet, and occasional English notes by a Catholic priest.

Mode of access: Internet.

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Religión y sociedad en la Granada cristiana: la Cruz de Mayo

The celebration of the Cruz of May – based on a fact for which tradition and the Legendi di Sancti Vulgari Storiado (Jacopo da Varazze, circa 1264) were possibly more relevant than history itself and extended by the ecclesiastical authority as a means of increasing faith – was accepted by people and was transformed into a social feast and an expression for local or social identity, which lead to peculiar rivalries amongst neighborhoods or streets. They had the aim to hold the best Cruz, leaving aside the feasts initial religious character. If the cross was, until the death of Christ, an instrument of martyrdom holding negative connotations (death, infamy, barbarism, etc.), it eventually transformed into a symbol of Christianity, a sign of triumph and everything related to Christ, and subsequently into a source of celebration and social festivity.

Analisi, evoluzione e verifiche di un dissesto di una porzione di edificio nell'Appennino tosco-emiliano

Il tema di ricerca verterà sulla determinazione delle cause di dissesto in atto su un edificio nell’Appennino tosco-emiliano. Questo, per evitare il crollo del fabbricato situato precisamente a Le Tagliole (Provincia di Modena). Mediante il reperimento di materiale bibliografico e pareri di professionisti locali si è cercato di verificare la stabilità del fabbricato, con conseguenti proposte di opere per migliorare la sua stabilità.

Catalytic upgrading of carboxylic acids and esters to bio fuels and bio chemicals

The research activity was focused on the transformation of methyl propionate (MP) into methyl methacrylate (MMA), avoiding the use of formaldehyde (FAL) thanks to a one-pot strategy involving in situ methanol (MeOH) dehydrogenation over the same catalytic bed were the hydroxy-methylation/dehydration of MP with FAL occurs. The relevance of such research line is related to the availability of cheap renewable bio-glycerol from biodiesel production, from which MP can be obtained via a series of simple catalytic reactions. Moreover, the conventional MMA synthesis (Lucite process) suffers from safety issues related to the direct use of carcinogenic FAL and depends on non-renewable MP. During preliminary studies, ketonization of carboxylic acids and esters has been recognized as a detrimental reaction which hinders the selective synthesis of MMA at low temperature, together with H-transfer hydrogenation with FAL or MeOH as the H-donor at higher temperatures. Therefore, ketonization of propionic acid (PA) and MP was investigated over several catalysts (metal oxides and metal phosphates), to obtain a better understanding of the structure-activity relationship governing the reaction and to design a catalyst for MMA synthesis capable to promote the desired reaction while minimizing ketonization and H-transfer. However, ketonization possesses scientific and industrial value itself and represents a strategy for the upgrade of bio oils from fast pyrolysis of lignocellulosic materials, a robust and versatile technology capable to transform the most abundant biomass into liquid biofuels. The catalysts screening showed that ZrO2 and La2O3 are the best catalysts, while MgO possesses low ketonization activity, but still, H-transfer parasitic hydrogenation of MMA reduces its yield over all catalysts. Such study resulted in the design of Mg/Ga mixed oxides that showed enhanced dehydrogenating activity towards MeOH at low temperatures. It was found that the introduction of Ga not only minimize ketonization, but also modulates catalyst basicity reducing H-transfer hydrogenations.

Nanostructured Systems for Electrocatalysis of Reduction Reactions for Energy Conversion Applications

Oxygen Reduction Reaction (ORR) requires a platinum-based catalyst to reduce the activation barrier. One of the most promising materials as alternative catalysts are carbon-based, graphene and carbon nanotubes (CNT) derivatives. ORR on a carbon-based substrate involves the less efficient two electrons process and the optimal four electrons process. New synthetic strategies to produce tunable graphene-based materials utilizing graphene oxide (GO) as a base inspired the first part of this work. Hydrogen Evolution Reaction (HER) is a slow process requiring also platinum or palladium as catalyst. In the second part of this work, we develop and use a technique for Ni nanoparticles electrodeposition using NiCl2 as precursor in the presence of ascorbate ligands. Electrodeposition of nano-nickel onto flat glassy carbon (GC) and onto nitrogen-doped reduced graphene oxide (rGO-N) substrates are studied. State of the art catalysts for CO2RR requires rare metals rhenium or rhodium. In recent years significant research has been done on non-noble metals and molecular systems to use as electro and photo-catalysts (artificial photosynthesis). As Cu-Zn alloys show good CO2RR performance, here we applied the same nanoparticle electrosynthesis technique using as precursors CuCl2 and Cl2Zn and observed successful formation of the nanoparticles and a notable activity in presence of CO2. Using rhenium complexes as catalysts is another popular approach and di-nuclear complexes have a positive cooperative effect. More recently a growing family of pre-catalysts based on the earth-abundant metal manganese, has emerged as a promising, cheaper alternative. Here we study the cooperative effects of di-nuclear manganese complexes derivatives when used as homogeneous electrocatalysts, as well as a rhenium functionalized polymer used as heterogeneous electrocatalyst.

Rilevamento e studio petrografico del Complesso di M. Calamita (Elba SE) nella zona di Spiaggia di Remaiolo

Lo scopo del lavoro di tesi consiste nello studio petrografico, dalla scala dell’affioramento a quella della sezione sottile, di rocce di basamento cristallino soggetto a metamorfismo e deformazione polifasiche. La zona di studio è la Spiaggia di Remaiolo, Elba SE. Questo settore da un punto di vista geologico fa parte del Complesso di M. Calamita, all’interno dell’Unità di Porto Azzurro. Gli affioramenti studiati mostrano diversi eventi metamorfici: il basamento metamorfico Ercinico e le sue coperture mesozoiche subiscono una sovraimpronta metamorfica Alpina di età Oligo-Miocenica correlabile alla strutturazione della catena dell’Appenino Settentrionale. Successivamente le rocce subiscono un’ulteriore sovraimpronta termometamorfica Mio-Pliocenica legata all’intrusione del plutone La Serra-Porto Azzurro. Il lavoro di campagna ha comportato un rilevamento di dettaglio per creare una Carta degli affioramenti (Allegato 1) e prelevare dei campioni rappresentativi delle litologie. Il lavoro di laboratorio si è svolto su 6 sezioni sottili, realizzate con i campioni prelevati in campagna, tramite l’ausilio del microscopio ottico a luce polarizzata.

Progettazione e calcolo strutturale di un serbatoio pressurizzato in alluminio per vettura ibrida

L’obiettivo della tesi è mettere a punto una metodologia che permetta di eseguire simulazioni sul comportamento di un serbatoio pressurizzato in alluminio di una vettura supersportiva ibrida.Verrà analizzato il sistema costituito dal serbatoio e da quattro bretelle di fissaggio, così da poter simulare differenti metodi di montaggio del serbatoio e valutare le tensioni generate dal fissaggio stesso. Lo strumento di lavoro utilizzato è ANSYS Mechanical, un software incluso nel pacchetto ANSYS Workbench che implementa un metodo di calcolo numerico agli elementi finiti. Per validare il modello sono stati testati in pressione due serbatoi, che e successivamente sono stati scansionati: la correlazione tra i dati sperimentali e le simulazioni ha mostrato che il modello, seppur semplificato, risulta sufficientemente accurato. Dopo i riscontri positivi avuti dalla validazione, sono stati applicati al modello sia carichi statici che ciclici, al fine di esprimere un giudizio sulla resistenza strutturale statica e a fatica del serbatoio. Successivamente, l’individuazione dei principali parametri di interesse ha consentito di effettuare la parametrizzazione del modello e l’ottimizzazione dei parametri. Ciò ha permesso di elaborare ulteriori considerazioni, sulla base delle quali sono stati forniti gli input di progettazione.

Sintesi del metil metacrilato mediante reazione tra metil propionato e metanolo in fase vapore

Il metil metacrilato (MMA) è un importante intermedio chimico principalmente utilizzato come monomero per la sintesi del poli metil metacrilato (PMMA). Il processo più moderno e sostenibile per la sintesi di MMA è il processo Alpha, che consiste nell'idrossi-metilazione del metil propionato (MP) con formaldeide (FAL) seguita dalla disidratazione dell’intermedio ottenuto. Il MP, attualmente prodotto tramite carbonilazione dell’etilene in presenza di metanolo (MeOH), può essere sintetizzato anche da glicerolo (coprodotto dalla produzione del biodiesel), un’economica molecola piattaforma di origine rinnovabile. Il principale svantaggio del processo Alpha consiste nell’utilizzo di FAL pura, notoriamente cancerogena. Questo inconveniente può essere superato promuovendo la formazione di FAL mediante deidrogenazione in-situ del MeOH, nello stesso reattore in cui avviene la reazione tra MP e FAL. Per questo motivo, la sintesi di MMA a partire da MP e MeOH è stata studiata in un reattore in continuo operante in fase vapore, investigando inizialmente due ossidi metallici come catalizzatori eterogenei: ossido di magnesio (MgO) e ossido di gallio (Ga2O3). Quest’ultimo è risultato molto più selettivo grazie alla moderata basicità ed al forte potere redox in grado di favorire la deidrogenazione del MeOH, tuttavia ha mostrato problemi di disattivazione. Nel tentativo di modulare le caratteristiche acido-base e redox dei catalizzatori, sono stati sintetizzati due ossidi misti con rapporto atomico Mg/Ga uguale a 10 e 20. L’introduzione di Ga3+ nella struttura aumenta l’attività catalitica per la deidrogenazione di MeOH e riduce la basicità totale rendendo il catalizzatore meno attivo per le reazioni parassite di chetonizzazione e riduzione tramite meccanismo di H-transfer. L’influenza dei principali parametri operativi (T, rapporto MeOH/MP, time factor) sul decorso della reazione è stato investigato approfonditamente ed è stato possibile proporre un complesso schema di reazione.

Development of urease enzyme inhibitors and assessment of their efficacy and ecotoxicity

This work study proposes novel and natural inhibitors of the enzyme urease, as more sustainable alternatives to the synthetic ones. Specifically, Deep Eutectic Solvents (DES) were used as an extractants and carriers of polyphenols extracted from waste biomass enriched in antioxidant compounds. The polyphenolic extracts with DES have been tested on lab-scale experiments to verify their effect on the reduction of the hydrolysis rate of urea-based fertilizers catalyzed by urease. The phytotoxicity and the soil ecotoxicity of DES and polyphenols formulations were then tested. DES resulted promising in terms of polyphenols extraction ability from biomass and as carriers of bioactive compounds in the agricultural field, showing non-damaging effects on plants (Avena sativa) and microarthropods in soil.

Design of an innovative electric vehicle simulator for Charging Systems' End-of-Line Testing

The trend related to the turnover of internal combustion engine vehicles with EVs goes by the name of electrification. The push electrification experienced in the last decade is linked to the still ongoing evolution in power electronics technology for charging systems. This is the reason why an evolution in testing strategies and testing equipment is crucial too. The project this dissertation is based on concerns the investigation of a new EV simulator design. that optimizes the structure of the testing equipment used by the company who commissioned this work. Project requirements can be summarized in the following two points: space occupation reduction and parallel charging implementation. Some components were completely redesigned, and others were substituted with equivalent ones that could perform the same tasks. In this way it was possible to reduce the space occupation of the simulator, as well as to increase the efficiency of the testing device. Moreover, the possibility of conjugating different charging simulations could be investigated by parallelly launching two testing procedures on a unique machine, properly predisposed for supporting the two charging protocols used. On the back of the results achieved in the body of this dissertation, a new design for the EV simulator was proposed. In this way, space reduction was obtained, and space occupation efficiency was improved with the proposed new design. The testing device thus resulted to be way more compact, enabling to gain in safety and productivity, along with a 25% cost reduction. Furthermore, parallel charging was implemented in the proposed new design since the conducted tests clearly showed the feasibility of parallel charging sessions. The results presented in this work can thus be implemented to build the first prototype of the new EV simulator.

Analysis and detection of partial discharges in an electric motor of a hybrid supercar.

The objective of this thesis was the development of a new detection method of partial discharge (PD) activity in the stator of an electrical hybrid supercar fed by a silicon carbide converter, for which detection with common methods make it very difficult to separate PD pulses from switching noise. This work focused on the analysis and detection of partial discharges making use of an antenna, a peak detector, and an oscilloscope capable of capturing the electromagnetic pulses emitted during PD activity. Validation of the proposed method was done by comparing the partial discharge inception voltage (PDIV) detected by this system with the one obtained from an optical method of proven accuracy, with different rise times and samples. Further development of this method, if proved successful on a full stator, can help increasing the overall reliability of the car, potentially allowing for real time detection of PD activity and predictive maintenance before failure of the insulation system in a hybrid vehicle.

Molecular simulations and modeling of pharmaceutically relevant RNA-processing enzymes

The two-metal-ion architecture is a structural feature found in a variety of RNA processing metalloenzymes or ribozymes (RNA-based enzymes), which control the biogenesis and the metabolism of vital RNAs, including non-coding RNAs (ncRNAs). Notably, such ncRNAs are emerging as key players for the regulation of cellular homeostasis, and their altered expression has been often linked to the development of severe human pathologies, from cancer to mental disorders. Accordingly, understanding the biological processing of ncRNAs is foundational for the development of novel therapeutic strategies and tools. Here, we use state-of the-art molecular simulations, complemented with X-ray crystallography and biochemical experiments, to characterize the RNA processing cycle as catalyzed by two two-metal-ion enzymes: the group II intron ribozymes and the RNase H1. We show that multiple and diverse cations are strategically recruited at and timely released from the enzymes’ active site during catalysis. Such a controlled cations’ trafficking leads to the recursive formation and disruption of an extended two-metal ion architecture that is functional for RNA-hydrolysis – from substrate recruitment to product release. Importantly, we found that these cations’ binding sites are conserved among other RNA-processing machineries, including the human spliceosome and CRISPR-Cas systems, suggesting that an evolutionarily-converged catalytic strategy is adopted by these enzymes to process RNA molecules. Thus, our findings corroborate and sensibly extend the current knowledge of two-metal-ion enzymes, and support the design of novel drugs targeting RNA-processing metalloenzymes or ribozymes as well as the rational engineering of novel programmable gene-therapy tools.