7 resultados para Technological innovations Economic aspects Queensland

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


Relevância:

100.00% 100.00%

Publicador:

Resumo:

La ricognizione delle opere composte da Filippo Tommaso Marinetti tra il 1909 e il 1912 è sostenuta da una tesi paradossale: il futurismo di Marinetti non sarebbe un'espressione della modernità, bensì una reazione anti-moderna, che dietro a una superficiale ed entusiastica adesione ad alcune parole d'ordine della seconda rivoluzione industriale nasconderebbe un pessimismo di fondo nei confronti dell'uomo e della storia. In questo senso il futurismo diventa un emblema del ritardo culturale e del gattopardismo italiano, e anticipa l’analoga operazione svolta in politica da Mussolini: dietro un’adesione formale ad alcune istanze della modernità, la preservazione dello Status Quo. Marinetti è descritto come un corpo estraneo rispetto alla cultura scientifica del Novecento: un futurista senza futuro (rarissime in Marinetti sono le proiezioni fantascientifiche). Questo aspetto è particolarmente evidente nelle opere prodotte del triennio 1908-1911, che non solo sono molto diverse dalle opere futuriste successive, ma per alcuni aspetti rappresentano una vera e propria antitesi di ciò che diventerà il futurismo letterario a partire dal 1912, con la pubblicazione del Manifesto tecnico della letteratura futurista e l'invenzione delle parole in libertà. Nelle opere precedenti, a un sostanziale disinteresse per il progressismo tecnologico corrispondeva un'attenzione ossessiva per la corporeità e un ricorso continuo all'allegoria, con effetti particolarmente grotteschi (soprattutto nel romanzo Mafarka le futuriste) nei quali si rilevano tracce di una concezione del mondo di sapore ancora medioevo-rinascimentale. Questa componente regressiva del futurismo marinettiano viene platealmente abbandonata a partire dal 1912, con Zang Tumb Tumb, salvo riaffiorare ciclicamente, come una corrente sotterranea, in altre fasi della sua carriera: nel 1922, ad esempio, con la pubblicazione de Gli indomabili (un’altra opera allegorica, ricca di reminiscenze letterarie). Quella del 1912 è una vera e propria frattura, che nel primo capitolo è indagata sia da un punto di vista storico (attraverso la documentazione epistolare e giornalistica vengono portate alla luce le tensioni che portarono gran parte dei poeti futuristi ad abbandonare il movimento proprio in quell'anno) che da un punto di vista linguistico: sono sottolineate le differenze sostanziali tra la produzione parolibera e quella precedente, e si arrischia anche una spiegazione psicologica della brusca svolta impressa da Marinetti al suo movimento. Nel secondo capitolo viene proposta un'analisi formale e contenutistica della ‘funzione grottesca’ nelle opere di Marinetti. Nel terzo capitolo un'analisi comparata delle incarnazioni della macchine ritratte nelle opere di Marinetti ci svela che quasi sempre in questo autore la macchina è associata al pensiero della morte e a una pulsione masochistica (dominante, quest'ultima, ne Gli indomabili); il che porta ad arrischiare l'ipotesi che l'esperienza futurista, e in particolare il futurismo parolibero posteriore al 1912, sia la rielaborazione di un trauma. Esso può essere interpretato metaforicamente come lo choc del giovane Marinetti, balzato in pochi anni dalle sabbie d'Alessandria d'Egitto alle brume industriali di Milano, ma anche come una reale esperienza traumatica (l'incidente automobilistico del 1908, “mitologizzato” nel primo manifesto, ma che in realtà fu vissuto dall'autore come esperienza realmente perturbante).

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Nowadays, it is clear that the target of creating a sustainable future for the next generations requires to re-think the industrial application of chemistry. It is also evident that more sustainable chemical processes may be economically convenient, in comparison with the conventional ones, because fewer by-products means lower costs for raw materials, for separation and for disposal treatments; but also it implies an increase of productivity and, as a consequence, smaller reactors can be used. In addition, an indirect gain could derive from the better public image of the company, marketing sustainable products or processes. In this context, oxidation reactions play a major role, being the tool for the production of huge quantities of chemical intermediates and specialties. Potentially, the impact of these productions on the environment could have been much worse than it is, if a continuous efforts hadn’t been spent to improve the technologies employed. Substantial technological innovations have driven the development of new catalytic systems, the improvement of reactions and process technologies, contributing to move the chemical industry in the direction of a more sustainable and ecological approach. The roadmap for the application of these concepts includes new synthetic strategies, alternative reactants, catalysts heterogenisation and innovative reactor configurations and process design. Actually, in order to implement all these ideas into real projects, the development of more efficient reactions is one primary target. Yield, selectivity and space-time yield are the right metrics for evaluating the reaction efficiency. In the case of catalytic selective oxidation, the control of selectivity has always been the principal issue, because the formation of total oxidation products (carbon oxides) is thermodynamically more favoured than the formation of the desired, partially oxidized compound. As a matter of fact, only in few oxidation reactions a total, or close to total, conversion is achieved, and usually the selectivity is limited by the formation of by-products or co-products, that often implies unfavourable process economics; moreover, sometimes the cost of the oxidant further penalizes the process. During my PhD work, I have investigated four reactions that are emblematic of the new approaches used in the chemical industry. In the Part A of my thesis, a new process aimed at a more sustainable production of menadione (vitamin K3) is described. The “greener” approach includes the use of hydrogen peroxide in place of chromate (from a stoichiometric oxidation to a catalytic oxidation), also avoiding the production of dangerous waste. Moreover, I have studied the possibility of using an heterogeneous catalytic system, able to efficiently activate hydrogen peroxide. Indeed, the overall process would be carried out in two different steps: the first is the methylation of 1-naphthol with methanol to yield 2-methyl-1-naphthol, the second one is the oxidation of the latter compound to menadione. The catalyst for this latter step, the reaction object of my investigation, consists of Nb2O5-SiO2 prepared with the sol-gel technique. The catalytic tests were first carried out under conditions that simulate the in-situ generation of hydrogen peroxide, that means using a low concentration of the oxidant. Then, experiments were carried out using higher hydrogen peroxide concentration. The study of the reaction mechanism was fundamental to get indications about the best operative conditions, and improve the selectivity to menadione. In the Part B, I explored the direct oxidation of benzene to phenol with hydrogen peroxide. The industrial process for phenol is the oxidation of cumene with oxygen, that also co-produces acetone. This can be considered a case of how economics could drive the sustainability issue; in fact, the new process allowing to obtain directly phenol, besides avoiding the co-production of acetone (a burden for phenol, because the market requirements for the two products are quite different), might be economically convenient with respect to the conventional process, if a high selectivity to phenol were obtained. Titanium silicalite-1 (TS-1) is the catalyst chosen for this reaction. Comparing the reactivity results obtained with some TS-1 samples having different chemical-physical properties, and analyzing in detail the effect of the more important reaction parameters, we could formulate some hypothesis concerning the reaction network and mechanism. Part C of my thesis deals with the hydroxylation of phenol to hydroquinone and catechol. This reaction is already industrially applied but, for economical reason, an improvement of the selectivity to the para di-hydroxilated compound and a decrease of the selectivity to the ortho isomer would be desirable. Also in this case, the catalyst used was the TS-1. The aim of my research was to find out a method to control the selectivity ratio between the two isomers, and finally to make the industrial process more flexible, in order to adapt the process performance in function of fluctuations of the market requirements. The reaction was carried out in both a batch stirred reactor and in a re-circulating fixed-bed reactor. In the first system, the effect of various reaction parameters on catalytic behaviour was investigated: type of solvent or co-solvent, and particle size. With the second reactor type, I investigated the possibility to use a continuous system, and the catalyst shaped in extrudates (instead of powder), in order to avoid the catalyst filtration step. Finally, part D deals with the study of a new process for the valorisation of glycerol, by means of transformation into valuable chemicals. This molecule is nowadays produced in big amount, being a co-product in biodiesel synthesis; therefore, it is considered a raw material from renewable resources (a bio-platform molecule). Initially, we tested the oxidation of glycerol in the liquid-phase, with hydrogen peroxide and TS-1. However, results achieved were not satisfactory. Then we investigated the gas-phase transformation of glycerol into acrylic acid, with the intermediate formation of acrolein; the latter can be obtained by dehydration of glycerol, and then can be oxidized into acrylic acid. Actually, the oxidation step from acrolein to acrylic acid is already optimized at an industrial level; therefore, we decided to investigate in depth the first step of the process. I studied the reactivity of heterogeneous acid catalysts based on sulphated zirconia. Tests were carried out both in aerobic and anaerobic conditions, in order to investigate the effect of oxygen on the catalyst deactivation rate (one main problem usually met in glycerol dehydration). Finally, I studied the reactivity of bifunctional systems, made of Keggin-type polyoxometalates, either alone or supported over sulphated zirconia, in this way combining the acid functionality (necessary for the dehydrative step) with the redox one (necessary for the oxidative step). In conclusion, during my PhD work I investigated reactions that apply the “green chemistry” rules and strategies; in particular, I studied new greener approaches for the synthesis of chemicals (Part A and Part B), the optimisation of reaction parameters to make the oxidation process more flexible (Part C), and the use of a bioplatform molecule for the synthesis of a chemical intermediate (Part D).

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Los accesorios metálicos de indumentaria constituyen uno de las fuentes materiales principales para aproximarse a la realidad social, cultural y económica de la población del Mediterráneo tardoantiguo. En el caso de los hallazgos de los siglos V y VI procedentes de la Península Ibérica y del suroeste de Francia, numerosos problemas de documentación han impedido extraer y desarrollar todo su potencial, tanto en lo referente al encuadre tipológico y cronológico de estos objetos como en la consiguiente fase interpretativa. Se hacía necesario acometer un nuevo estudio monográfico que actualizara el panorama de la investigación. El trabajo cataloga, data y clasifica tipológicamente más de cuatro millares de fíbulas y accesorios de cinturón recuperados en casi medio millar de yacimientos localizados en los actuales Portugal, España, Andorra y Francia. El resultado permite aproximarse a las áreas de producción y modalidades de circulación y utilización de cada uno de los tipos individualizados. Una veintena de indumentarias distintas, definidas por combinaciones de distintos tipos de accesorios en contextos funerarios, ha sido identificada. Parte de éstas constituye la base principal de un sistema cronológico organizado en seis fases distintas que cubren una cronología situada aproximadamente entre las últimas décadas del siglo IV y las últimas décadas del siglo VI. La investigación acomete asimismo el análisis de la implantación de los accesorios y de las indumentarias relacionadas con ellos en el paisaje tardoantiguo de Hispania y la Galia. El resultado permite reconstruir secuencias regionales de evolución indumentaria y establecer relaciones entre diversas tipologías de contextos funerarios y habitativos y los tipos de indumentaria previamente definidos. Los resultados permiten renovar la mirada sobre este tipo de objetos y el lugar que ocuparon en la vida cotidiana de muchos de los habitantes del regnum visigodo temprano.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

La tesi affronta le problematiche fiscali della riorganizzazione societaria e la soluzione adoperata nell’Unione europea per le operazioni di carattere transfrontaliere. Si parte dalla definizione del termine “riorganizzazione societaria”, evidenziando le sue matici economiche e la varietà del suo contenuto secondo l’ordinamento giuridico e la branca del diritto di riferimento. Si prosegue sulla correlazione fra l’ampliazione del contenuto della libertà di stabilimento, dovuta maggiormente all’attività interpretativa della Corte di giustizia, e l’allargamento del concetto di riorganizzazione societaria nel quadro normativo dell’Unione. Si procede dunque all’analisi del regime fiscale comune della direttiva 2009/133/CE intravedendosi i suoi sviluppi successivi. In sede di conclusioni, si apporta un breve riassunto sullo stato della questione in Brasile e si riflette sull’attendibilità del modello impositivo dell’Unione quale parametro per una futura riforma fiscale in Brasile.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Government policies play a critical role in influencing market conditions, institutions and overall agricultural productivity. The thesis therefore looks into the history of agriculture development in India. Taking a political economy perspective, the historical account looks at significant institutional and technological innovations carried out in pre- independent and post independent India. It further focuses on the Green Revolution in Asia, as forty years after; the agricultural community still faces the task of addressing recurrent issue of food security amidst emerging challenges, such as climate change. It examines the Green Revolution that took place in India during the late 1960s and 70s in a historical perspective, identifying two factors of institutional change and political leadership. Climate change in agriculture development has become a major concern to farmers, researchers and policy makers alike. However, there is little knowledge on the farmers’ perception to climate change and to the extent they coincide with actual climatic data. Using a qualitative approach,it looks into the perceptions of the farmers in four villages in the states of Maharashtra and Andhra Pradesh. While exploring the adaptation strategies, the chapter looks into the dynamics of who can afford a particular technology and who cannot and what leads to a particular adaptation decision thus determining the adaptive capacity in water management. The final section looks into the devolution of authority for natural resource management to local user groups through the Water Users’ Associations as an important approach to overcome the long-standing challenges of centralized state bureaucracies in India. It addresses the knowledge gap of why some local user groups are able to overcome governance challenges such as elite capture, while others-that work under the design principles developed by Elinor Ostrom. It draws conclusions on how local leadership, can be promoted to facilitate participatory irrigation management.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Il sistema comune europeo dell’imposta sul valore aggiunto privilegia caratteri e finalità economiche nel definire chi siano gli operatori economici soggetti all’IVA. Una disciplina particolare è, tuttavia, prevista per i soggetti di diritto pubblico che, oltre alla principale attività istituzionale, esercitano un’attività di carattere economico. Ai sensi dell’articolo 13 della Direttiva del 28 novembre 2006, 2006/112/CE, gli Stati, le Regioni, le Province, i Comuni e gli altri enti di diritto pubblico, in relazione alle attività ed operazioni che essi effettuano in quanto pubbliche autorità, non sono considerati soggetti passivi IVA anche se in relazione ad esse percepiscono diritti, canoni, contributi o retribuzioni. La vigente disciplina europea delle attività economiche esercitate dagli enti pubblici, oltre che inadeguata al contesto economico attuale, rischia di diventare un fattore che influenza negativamente l’efficacia del modello impositivo dell’IVA e l’agire degli enti pubblici. La tesi propone un modello alternativo che prevede l’inversione dell’impostazione attuale della Direttiva IVA al fine di considerare, di regola, soggetti passivi IVA gli organismi pubblici che svolgono - ancorché nella veste di pubblica autorità - attività oggettivamente economiche.

Relevância:

100.00% 100.00%

Publicador:

Resumo:

Until few years ago, 3D modelling was a topic confined into a professional environment. Nowadays technological innovations, the 3D printer among all, have attracted novice users to this application field. This sudden breakthrough was not supported by adequate software solutions. The 3D editing tools currently available do not assist the non-expert user during the various stages of generation, interaction and manipulation of 3D virtual models. This is mainly due to the current paradigm that is largely supported by two-dimensional input/output devices and strongly affected by obvious geometrical constraints. We have identified three main phases that characterize the creation and management of 3D virtual models. We investigated these directions evaluating and simplifying the classic editing techniques in order to propose more natural and intuitive tools in a pure 3D modelling environment. In particular, we focused on freehand sketch-based modelling to create 3D virtual models, interaction and navigation in a 3D modelling environment and advanced editing tools for free-form deformation and objects composition. To pursuing these goals we wondered how new gesture-based interaction technologies can be successfully employed in a 3D modelling environments, how we could improve the depth perception and the interaction in 3D environments and which operations could be developed to simplify the classical virtual models editing paradigm. Our main aims were to propose a set of solutions with which a common user can realize an idea in a 3D virtual model, drawing in the air just as he would on paper. Moreover, we tried to use gestures and mid-air movements to explore and interact in 3D virtual environment, and we studied simple and effective 3D form transformations. The work was carried out adopting the discrete representation of the models, thanks to its intuitiveness, but especially because it is full of open challenges.