Biomasse e loro quantificazione economica per un efficiente uso dell'energia

Biomasses and their possible use as energy resource are of great interest today, and the general problem of energy resources as well. In the present study the key questions of the convenience, from both energy and economy standpoints, have been addressed without any bias: the problem has been handled starting from “philosophical” bases disregarding any pre-settled ideology or political trend, but simply using mathematical approaches as logical tools for defining balances in a right way. In this context quantitative indexes such as LCA and EROEI have been widely used, together with multicriteria methods (such as ELECTRE) as decision supporting tools. This approach permits to remove mythologies, such as the unrealistic concept of clean energy, or the strange idea of biomasses as a magic to solve every thing in the field of the energy. As a consequence the present study aims to find any relevant aspect potentially useful for the society, looking at any possible source of energy without prejudices but without unrealistic expectations too. For what concerns biomasses, we studied in great details four very different cases of study, in order to have a scenario as various as much we can. A relevant result is the need to use biomasses together with other more efficient sources, especially recovering by-products from silviculture activities: but attention should be paid to the transportation and environmental costs. Another relevant result is the very difficult possibility of reliable evaluation of dedicated cultures as sources for “biomasses for energy”: the problem has to be carefully evaluated case-by-case, because what seems useful in a context, becomes totally disruptive in another one. In any case the concept itself of convenience is not well defined at a level of macrosystem: it seems more appropriate to limit this very concept at a level of microsystem, considering that what sounds fine in a limited well defined microsystem may cause great damage in another slightly different, or even very similar, microsystem. This approach seems the right way to solve the controversy about the concept of convenience.

Development discourse in Romania: from Socialism to EU Membership

With their accession to the European Union, twelve new countries - Romania among them - (re)entered the international community of international donors. In the history of development aid this can be seen as a unique event: it is for the first time in history that such a large number of countries become international donors, with such short notice and in such a particular context that sees some scholars announcing the ‘death’ of development. But in spite of what might be claimed regarding the ‘end’ of the development era, development discourse seems to be rather vigorous and in good health: it is able to extert an undeniable force of attraction over the twelve countries that, in a matter of years, have already convinced themselves of its validity and adhered to its main tenets. This thesis collects evidence for improving our understanding of this process that sees the co-optation of twelve new countries to the dominant theory and practice of development cooperation. The evidence collected seems to show that one of the tools employed by the promoters of this co-optation process is that of constructing the ‘new’ Member States as ‘new’, inexpert donors that need to learn from the ‘old’ ones. By taking a case-study approach, this thesis gathers data that suggests that conceiving of the ‘twelve’ as ‘new’ donors is both historically inaccurate and value-ladden. On one hand, Romania’s case-study illustrates how in the (socialist) past at least one in the group of the twelve was particularly conversant in the discourse of international development. On the other hand, the process of co-optation, while being presented as a knowledgeproducing process, can also be seen as an ignorance-producing procedure: Romania, along with its fellow new Member States, takes the opportunity of ‘building its capacity’ and ‘raising its awareness’ of development cooperation along the line drawn by the European Union, but at the same time it seems to un-learn and ‘lower’ its awareness of development experience in the (socialist) past. This is one possible reading of this thesis. At a different level, this thesis can also be seen as an attempt to account of almost five decades of international development discourse in one specific country – Romania – in three different socio-political contexts: the socialist years (up to the year 1989), the ‘transition years’ (from 1989 to the pre-accession years) and the membership to the European Union. In this second reading, the thesis seeks to illustrate how – contrary to widespread beliefs – before 1989 Romania’s international development discourse was particularly vivid: in the most varied national and international settings President Ceausescu unfolded an extensive discursive activity on issues pertaining to international development; generous media coverage of affairs concerning the developing countries and their fight for development was the rule rather than the exception; the political leadership wanted the Romanians not only to be familiarized with (or ‘aware of’ to use current terminology) matters of underdevelopment, but also to prove a sense of solidarity with these countries, as well as a sense of pride for the relations of ‘mutual help’ that were being built with them; finally, international development was object of academic attention and the Romanian scholars were able not only to reflect on major developments, but could also formulate critical positions towards the practices of development aid. Very little remains of all this during the transition years, while in the present those who are engaged in matters pertaining to international development do so with a view of building Romania as an EU-compliant donor.

Comparison between analytical and numerical methods for the assessment of masonry arch bridges: Case study of Clemente Bridge on Savio river

This research has focused on the study of the behavior and of the collapse of masonry arch bridges. The latest decades have seen an increasing interest in this structural type, that is still present and in use, despite the passage of time and the variation of the transport means. Several strategies have been developed during the time to simulate the response of this type of structures, although even today there is no generally accepted standard one for assessment of masonry arch bridges. The aim of this thesis is to compare the principal analytical and numerical methods existing in literature on case studies, trying to highlight values and weaknesses. The methods taken in exam are mainly three: i) the Thrust Line Analysis Method; ii) the Mechanism Method; iii) the Finite Element Methods. The Thrust Line Analysis Method and the Mechanism Method are analytical methods and derived from two of the fundamental theorems of the Plastic Analysis, while the Finite Element Method is a numerical method, that uses different strategies of discretization to analyze the structure. Every method is applied to the case study through computer-based representations, that allow a friendly-use application of the principles explained. A particular closed-form approach based on an elasto-plastic material model and developed by some Belgian researchers is also studied. To compare the three methods, two different case study have been analyzed: i) a generic masonry arch bridge with a single span; ii) a real masonry arch bridge, the Clemente Bridge, built on Savio River in Cesena. In the analyses performed, all the models are two-dimensional in order to have results comparable between the different methods taken in exam. The different methods have been compared with each other in terms of collapse load and of hinge positions.