913 resultados para Ottimizzazione di portafoglio metodo della programmazione dinamica
Resumo:
Il seguente elaborato è la diretta conseguenza di un periodo di stage, pari a cinque mesi, svolto presso l’azienda INTERTABA S.p.A., a Zola Predosa (BO). Il Dipartimento presso cui è stato svolto il tirocinio è l’Engineering. In particolare è stata compiuta un’analisi dei KPIs presenti e sono state proposte delle azioni migliorative. Il lavoro si è sviluppato in tre fasi. Nella prima fase è stata fatta un’analisi dei KPIs attuali per ciascuna funzione appartenente all’Engineering: Engineering Support, Project Engineering, Plant & Utilities Maintenance, Technical Warehouse e General Services. Nella seconda fase sono state descritte, per ciascuna funzione, alcune proposte migliorative per i KPIs presenti. Infine, per alcune funzioni, sono state proposte alcune iniziative in merito all’implementazione di nuovi KPIs.
Resumo:
Low-pressure/high-temperature (LP/HT) metamorphic belts are characterised by rocks that experienced abnormal heat flow in shallow crustal levels (T > 600 °C; P < 4 kbar) resulting in anomalous geothermal gradients (60-150 °C/km). The abnormal amount of heat has been related to crustal underplating of mantle-derived basic magmas or to thermal perturbation linked to intrusion of large volumes of granitoids in the intermediate crust. In particular, in this latter context, magmatic or aqueous fluids are able to transport relevant amounts of heat by advection, thus favouring regional LP/HT metamorphism. However, the thermal perturbation consequent to heat released by cooling magmas is responsible also for contact metamorphic effects. A first problem is that time and space relationships between regional LP/HT metamorphism and contact metamorphism are usually unclear. A second problem is related to the high temperature conditions reached at different crustal levels. These, in some cases, can completely erase the previous metamorphic history. Notwithstanding this problem is very marked in lower crustal levels, petrologic and geochronologic studies usually concentrate in these attractive portions of the crust. However, only in the intermediate/upper-crustal levels of a LP/HT metamorphic belt the tectono-metamorphic events preceding the temperature peak, usually not preserved in the lower crustal portions, can be readily unravelled. The Hercynian Orogen of Western Europe is a well-documented example of a continental collision zone with widespread LP/HT metamorphism, intense crustal anatexis and granite magmatism. Owing to the exposure of a nearly continuous cross-section of the Hercynian continental crust, the Sila massif (northern Calabria) represents a favourable area to understand large-scale relationships between granitoids and LP/HT metamorphic rocks, and to discriminate regional LP/HT metamorphic events from contact metamorphic effects. Granulite-facies rocks of the lower crust and greenschist- to amphibolite-facies rocks of the intermediate-upper crust are separated by granitoids emplaced into the intermediate level during the late stages of the Hercynian orogeny. Up to now, advanced petrologic studies have been focused mostly in understanding P-T evolution of deeper crustal levels and magmatic bodies, whereas the metamorphic history of the shallower crustal levels is poorly constrained. The Hercynian upper crust exposed in Sila has been subdivided in two different metamorphic complexes by previous authors: the low- to very low-grade Bocchigliero complex and the greenschist- to amphibolite-facies Mandatoriccio complex. The latter contains favourable mineral assemblages in order to unravel the tectono-metamorphic evolution of the Hercynian upper crust. The Mandatoriccio complex consists mainly of metapelites, meta-arenites, acid metavolcanites and metabasites with rare intercalations of marbles and orthogneisses. Siliciclastic metasediments show a static porphyroblastic growth mainly of biotite, garnet, andalusite, staurolite and muscovite, whereas cordierite and fibrolite are less common. U-Pb ages and internal features of zircons suggest that the protoliths of the Mandatoriccio complex formed in a sedimentary basin filled by Cambrian to Silurian magmatic products as well as by siliciclastic sediments derived from older igneous and metamorphic rocks. In some localities, metamorphic rocks are injected by numerous aplite/pegmatite veins. Small granite bodies are also present and are always associated to spotted schists with large porphyroblasts. They occur along a NW-SE trending transcurrent cataclastic fault zone, which represents the tectonic contact between the Bocchigliero and the Mandatoriccio complexes. This cataclastic fault zone shows evidence of activity at least from middle-Miocene to Recent, indicating that brittle deformation post-dated the Hercynian orogeny. P-T pseudosections show that micaschists and paragneisses of the Mandatoriccio complex followed a clockwise P-T path characterised by four main prograde phases: thickening, peak-pressure condition, decompression and peak-temperature condition. During the thickening phase, garnet blastesis started up with spessartine-rich syntectonic core developed within micaschists and paragneisses. Coevally (340 ± 9.6 Ma), mafic sills and dykes injected the upper crustal volcaniclastic sedimentary sequence of the Mandatoriccio complex. After reaching the peak-pressure condition (≈4 kbar), the upper crust experienced a period of deformation quiescence marked by the static overgrowths of S2 by Almandine-rich-garnet rims and by porphyroblasts of biotite and staurolite. Probably, this metamorphic phase is related to isotherms relaxation after the thickening episode recorder by the Rb/Sr isotopic system (326 ± 6 Ma isochron age). The post-collisional period was mainly characterised by decompression with increasing temperature. This stage is documented by the andalusite+biotite coronas overgrown on staurolite porphyroblasts and represents a critical point of the metamorphic history, since metamorphic rocks begin to record a significant thermal perturbation. Peak-temperature conditions (≈620 °C) were reached at the end of this stage. They are well constrained by some reaction textures and mineral assemblages observed almost exclusively within paragneisses. The later appearance of fibrolitic sillimanite documents a small excursion of the P-T path across the And-Sil boundary due to the heating. Stephanian U-Pb ages of monazite crystals from the paragneiss, can be related to this heating phase. Similar monazite U-Pb ages from the micaschist combined with the lack of fibrolitic sillimanite suggest that, during the same thermal perturbation, micaschists recorded temperatures slightly lower than those reached by paragneisses. The metamorphic history ended with the crystallisation of cordierite mainly at the expense of andalusite. Consequently, the Ms+Bt+St+And+Sill+Crd mineral assemblage observed in the paragneisses is the result of a polyphasic evolution and is characterised by the metastable persistence of the staurolite in the stability fields of the cordierite. Geologic, geochronologic and petrographic data suggest that the thermal peak recorded by the intermediate/upper crust could be strictly connected with the emplacement of large amounts of granitoid magmas in the middle crust. Probably, the lithospheric extension in the relatively heated crust favoured ascent and emplacement of granitoids and further exhumation of metamorphic rocks. After a comparison among the tectono-metamorphic evolutions of the different Hercynian crustal levels exposed in Sila, it is concluded that the intermediate/upper crustal level offers the possibility to reconstruct a more detailed tectono-metamorphic history. The P-T paths proposed for the lower crustal levels probably underestimate the amount of the decompression. Apart from these considerations, the comparative analysis indicates that P-T paths at various crustal levels in the Sila cross section are well compatible with a unique geologic scenario, characterized by post-collisional extensional tectonics and magmas ascent.
Resumo:
Il progetto si sviluppa nell’area dell’ex Eridania di Forlì, un’area molto vasta, adiacente al centro storico e come tema della Tesi abbiamo deciso di studiare un progetto che potesse contenere funzioni pubbliche a disposizione di tutti i cittadini. Ci è sembrato interessante ragionare sull’area in questi termini poiché dagli studi effettuati è risultato che la città di Forlì è priva di un polo culturale compatto che possa costituire un punto di ritrovo per i forlivesi. Nelle nostre intenzioni gli spazi progettati dovranno ospitare attività espositive, concerti, spettacoli all’aperto, rappresentazioni teatrali, conferenze e laboratori artistici che coinvolgano tutte le fasce d’età. Importante per noi era portare all’interno di quest’area dismessa nuove funzioni culturali di cui Forlì è oggi carente. Dall’analisi svolta sulla città è emerso che gli spazi esistenti dedicati ad attività per lo spettacolo non sono sufficienti a soddisfare le esigenze dei cittadini sia a livello quantitativo che di assortimento. Abbiamo perciò deciso di inserire nel progetto auditorium, teatro, teatro all’aperto, laboratori artistici, zone espositive, attività annesse come uffici per l’amministrazione, biglietterie, info point e un grande parco. La prima problematica che abbiamo cercato di risolvere è stata quella dell’attraversamento della ferrovia e, più in particolare, di un collegamento con il centro storico della città e con lo sviluppo di Forlì in generale che l’ha sempre vista come un limite invalicabile. Il problema è stato affrontato ipotizzando la realizzazione di un edificio su via Vittorio Veneto adibito a commercio e terziario dal quale, attraverso un ponte che oltrepassa la ferrovia, si giunge a un edificio, all’interno dell’area, che ospita i servizi di risalita, alcuni uffici e un bar. La scelta è stata quella di non porci ortogonalmente agli edifici affacciati su questa importante arteria ma di legarci all’intero progetto che segue l’orientamento dettato dalle preesistenze. All’interno dell’area spicca per dimensioni il corpo principale dell’ex Eridania che, conserviamo eliminando le superfetazioni e intervenendo per la messa in sicurezza e per permetterne l’adeguata fruibilità. La scelta di riordinare il prospetto Nord di questo edificio nasce dalla volontà di realizzare una grande corte sulla quale si affacciassero tutti gli edifici ad esclusione dei vecchi magazzini che ne risultano racchiusi all’interno e del teatro all’aperto che rimane immerso nel verde. Per definire questa corte abbiamo pensato a un porticato che proseguisse, seguendone l’aspetto, le dimensioni e il ritmo dei pilastri, quello già esistente a lato dell’edificio conservato dell’ex zuccherificio e che fungesse da percorso coperto per raggiungere i diversi laboratori artistici che si innestano su questo. A chiudere il quarto lato della corte sono il teatro e l’auditorium, simmetrici rispetto all’asse del progetto che è dato dalle vasche originariamente usate per il lavaggio delle barbabietole, allineate con l’edificio principale dell’ex zuccherificio. Per rendere la direzione ancora più evidente decidiamo di proseguirla con un tratto d’acqua diretto verso il teatro all’aperto, conclusione della stessa. Gli edifici di progetto sono immersi in un grande parco caratterizzato dalla vegetazione già esistente nell’area, cresciuta durante l’abbandono della stessa. Così facendo manteniamo delle zone che possono definirsi boschive, dove la vegetazione è molto fitta e intricata, e altre invece più libere dagli alberi e quindi utilizzabili per altre funzioni ricreative. Un diverso trattamento è riservato alla zona di parco racchiusa tra i due percorsi rettilinei e simmetrici che collegano il teatro all’aperto alla piazza: qui si è preferito eliminare la vegetazione esistente ricavando un grande prato libero definito da filari di alberi opportunamente disposti per focalizzare l’attenzione sul teatro stesso.
Resumo:
Waste management is becoming, year after year, always more important both for the costs associated with it and for the ever increasing volumes of waste generated. The discussion on the fate of organic fraction of municipal solid waste (OFMSW) leads everyday to new solutions. Many alternatives are proposed, ranging from incineration to composting passing through anaerobic digestion. “For Biogas” is a collaborative effort, between C.I.R.S.A. and R.E.S. cooperative, whose main goal is to generate “green” energy from both biowaste and sludge anaerobic co-digestion. Specifically, the project include a pilot plant receiving dewatered sludge from both urban and agro-industrial sewage (DS) and the organic fraction of MSW (in 2/1 ratio) which is digested in absence of oxygen to produce biogas and digestate. Biogas is piped to a co-generation system producing power and heat reused in the digestion process itself, making it independent from the national grid. Digestate undergoes a process of mechanical separation giving a liquid fraction, introduced in the treatment plant, and a solid fraction disposed in landfill (in future it will be further processed to obtain compost). This work analyzed and estimated the impacts generated by the pilot plant in its operative phase. Once the model was been characterized, on the basis of the CML2001 methodology, a comparison is made with the present scenario assumed for OFMSW and DS. Actual scenario treats separately the two fractions: the organic one is sent to a composting plant, while sludge is sent to landfill. Results show that the most significant difference between the two scenarios is in the GWP category as the project "For Biogas" is able to generate “zero emission” power and heat. It also generates a smaller volume of waste for disposal. In conclusion, the analysis evaluated the performance of two alternative methods of management of OFMSW and DS, highlighting that "For Biogas" project is to be preferred to the actual scenario.
Resumo:
Starting from the contexts on which the researches about migrant minors and adolescents have been concentrated so far, school, free time, friends, family, society integration, this work puts attention on gender dimension, supporting the ideas that socialization is a life-long process, that gender and gender roles are a cultural construction and the subject has multiple identities. The research aim to understand if being male or female, related with ethnic and cultural origin, influences the identity construction, the gender belonging and roles, the behaviours, in a different way, in interaction with the different everyday contexts. The research points out how being male or female affects: - daily choices, expectations and behaviours inside peer group, family and school; - future expectations as adult inside family, work and society; - idea about the adolescence and the self-decription as adolescent, female, male and immigrant. The analysis highlights that the gender belonging, as the ethnic and cultural belonging, doesn’t drive behaviours, attitudes, expectations totally to tradition or totally to “western way”, in the different everyday contexts. There is rather a combination of these ways, choosing the one or the other way in the different contexts according to be in a position in which there are more or less contacts with the society they live in. Differently, the self perception as adolescent and as individual is relatively independent from gender and ethniccultural belonging, over which prevail the idea of “ peer normality”. Above all, it is important to put in evidence that they are experiencing a very high level of complexity and change as adolescent and migrant or migrant’ son. Personal, cultural and social transitions can explain a large part of variability and our difficulty to construct high defined classifications.