Il paradigma della sostenibilità nel settore alimentare: problematiche attuali e prospettive future

Parallelamente al progressivo emergere delle esternalità negative prodotte dal paradigma economico predominante a livello globale, si è fatto strada il paradigma dello sviluppo sostenibile, che si prefigge di tenere conto in misura congiunta di tre dimensioni (economica, sociale e ambientale). Tuttavia, tale paradigma non coincide necessariamente con il più ampio e controverso concetto di sostenibilità ambientale. L’applicazione di tale concetto ai sistemi alimentari consente di leggere trasversalmente e collegare i temi che oggigiorno occupano i primi posti nelle agende politiche, nelle strategie aziendali e nel dibattito pubblico. La diffusione sempre maggiore del paradigma della sostenibilità ha portato il mondo aziendale a mettere a punto strategie di green marketing; tuttavia, determinate pratiche possono risultare ingannevoli nei confronti dei consumatori, traducendosi nel cosiddetto greenwashing. Alla luce di tale deriva negativa, si rende evidente l’importanza di ricostruire le filiere dei prodotti alimentari per poter attuare scelte di consumo più consapevoli. Nell’ambito dei sistemi alimentari, da una parte si è affermato a livello globale un modello agroindustriale, dall’altra è emerso un modello di filiera corta che si è declinato nelle molteplici forme dei cosiddetti alternative food networks. Considerando sia il mondo attuale che gli scenari futuri che si prospettano, in un mondo sempre più sovrappopolato, segnato da un progressivo aumento della domanda globale di cibo, dalla vulnerabilità che segue alla comparsa di sconvolgimenti di varia natura, dall’intensificarsi dei processi legati al cambiamento climatico e dalle innumerevoli sfide a questi connessi, scaturisce un cruciale interrogativo: quale sarà la strada più sostenibile da intraprendere, con una visione di lungo termine? Esiste una risposta esaustiva e una soluzione univoca, o bisognerà adottare una visione sistemica che guidi azioni compartecipate su più livelli?

Economic and Environmental Optimization of Ornamental Stone Block Cutting with a 3D Algorithm

This thesis focuses on finding the optimum block cutting dimensions in terms of the environmental and economic factors by using a 3D algorithm for a limestone quarry in Foggia, Italy. The environmental concerns of quarrying operations are mainly: energy consumption, material waste, and pollution. The main economic concerns are the block recovery, the selling prices, and the production costs. Fractures adversely affect the block recovery ratio. With a fracture model, block production can be optimized. In this research, the waste volume produced by quarrying was minimised to increase the recovery ratio and ensure economic benefits. SlabCutOpt is a software developed at DICAM–University of Bologna for block cutting optimization which tests different cutting angles on the x-y-z planes to offer up alternative cutting methods. The program tests several block sizes and outputs the optimal result for each entry. By using SlabCutOpt, ten different block dimensions were analysed, the results indicated the maximum number of non-intersecting blocks for each dimension. After analysing the outputs, the block named number 1 with the dimensions ‘1mx1mx1m’ had the highest recovery ratio as 43% and the total Relative Money Value (RMV) with a value of 22829. Dimension number 1, also had the lowest waste volume, with a value of 3953.25 m3, for the total bench. For cutting the total bench volume of 6932.25m3, the diamond wire cutter had the lowest dust emission values for the block with the dimension ‘2mx2mx2m’, with a value of 24m3. When compared with the Eco-Label standards, block dimensions having surface area values lower than 15m2, were found to fit the natural resource waste criteria of the label, as the threshold required 25% of minimum recovery [1]. Due to the relativity of production costs, together with the Eco-Label threshold, the research recommends the selection of the blocks with a surface area value between 6m2 and 14m2.

Study of recycled Rap and Ra as alternative aggregates for pavements' sub-base and base

Nowadays, an important world’s population growth forecast establish that an increase of 2 billion people is expected by 2050. (UN,2019). This increment of people worldwide involves more humans, as well as growth of the demand for the construction of new residential, institutional, industrial, and infrastructural areas, prompting to a higher consumption of natural resources as required for construction materials. In addition, an effect of this population growth is the production and accumulation of waste causing a serious environmental and economic issue around the world. As an alternative to just producing more waste at the final stage of a building, house, road, among other concrete-based structures, adequate techniques must be applied for recycling and reusing these potential materials. The main priority of the thesis is to foment and evaluate the sustainable construction work leading to environmental-friendly actions that promote the reuse and recycling of construction waste, focusing on the use of construction recycled construction materials as an alternative for sub-base and base of road structure application. This thesis is committed to the analysis of the several laboratory tests carried out for achieving the physical-mechanical properties of the studied materials (recycled concrete aggregates + reclaimed asphalt pavement (RCA+RAP) and stabilized crushed sleepers). All these tests have been carried out in the Laboratory of Roads from the University of Bologna and in the experimental site in CAR srl., at Imola. The results are reported in tables, graphs, and are discussed. The mechanical properties values obtained from the laboratory tests are analysed and compared with standard values declared in the Italian and European normative for roads construction and to the results obtained from in-situ tests in the experimentation field (CAR srl in Imola) with the same materials. This to analyse the performance of them under natural conditions.