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Low temperature CO Oxidation and Preferential Oxidation of CO Over Nano-Structured Base Metal Oxide Catalysts
Get PDFDemand of pure hydrogen is considerably increased by the development of polymer electrolyte membrane fuel cell technology. Hydrogen produced from the hydrocarbon
sources with steam reforming followed by water gas shift reaction contains carbon monoxide (CO), which is not suitable for the efficient functioning of the PEM fuel cells. Preferential CO oxidation is the most effective and economic ways to reduce trace amounts of CO from the hydrogen stream. Present PhD work deals with the development of base metal oxide catalyst combinations for CO oxidation and preferential CO oxidation reaction. Four base metal oxide catalyst systems are investigated for CO oxidation in the presence and absence of hydrogen. The catalyst combinations investigated for the reactions include
copper-cobalt, iron-cobalt, copper-cerium and a tri-component copper-cerium-iron oxide. Copper-cobalt, iron-cobalt, copper-cerium and cerium-iron oxide catalysts combinations were prepared by hard template method. Chelating-impregnation and incipient wetness impregnation techniques used to deposit copper on the cerium-iron oxide support. Gold deposited iron-cobalt and cerium-iron oxide catalysts were also prepared for comparing the catalytic activity with iron-cobalt and copper-cerium-iron oxide catalyst. All the catalysts were characterized as to their structure, morphology, texture and redox features by X-ray
diffraction, transmission electron microscopy, N2 physisorption and temperatureprogrammed reduction with hydrogen, respectively. It was observed that doping cobalt oxide structure with copper and iron are beneficial for
improving the activity of the oxide. Superiority of copper-cobalt is observed above 100°C for CO oxidation. In preferential oxidation, higher CO and oxygen conversions were observed over such system, compared to pure cobalt oxide. Gold deposited on iron-cobalt oxide was highly active for CO oxidation in the absence of hydrogen, but its activity was not maintained in the presence of hydrogen. Iron-cobalt oxide catalyst was the highly active catalyst in PROX. Copper-cerium oxide catalysts showed similar activity in CO oxidation and preferential oxidation reaction. No remarkable differences between the catalysts were observed. Catalytic activity for both CO oxidation and preferential oxidation reactions on the cerium-iron support was improved by the presence of copper. Copperbased catalyst showed improved activity and selectivity in preferential oxidation compared to gold based catalysts
Sindromi drepanocitiche: studio di fattibilità di strategie di prevenzione e rimodellamento della rete assistenziale in un contesto in evoluzione
Get PDFSickle cell disease (SCD) is the first genetic disease in the world and remains largely ignored by the population but also by health professionals. SCD is characterized by a variable clinical expression; however most of the patients are at risk to develop acute and severe complications conducting to a fatal issue. Reliable and accurate epidemiological data is a prerequisite for a cost effective prevention program for inherited disorders, which however, is lacking in a number of developing countries. Here we report the first detailed population study in the Piedmont region, north-west Italy, designed to estimate the frequency and distribution of patients with sickle cell disease, annual number of patients newly diagnosed as having SCD, proportion of the patients receiving a regular care in a comprehensive care setting. This study analyzes the adequacy between the services offered for these patients and the real need in this Italian country.
OBJECTIVE:
The purpose is to estimate the prevalence of sickle cell disease in the Piedmont region and the need for prevention strategies, to evaluate the feasibility of neonatal screening and to propose a realistic healthcare program.
METHODS:
The estimate of the SCD prevalence changes between January 1978 and December 2011 in the Piedmont region was based on three regional data sources. All consecutive patients with SCD laboratoristic diagnosis were included and specialistic care was offered. For all patients, the demographic and clinical features and the circumstances of SCD diagnosis were described. The next step was to analyse the current prevention and healthcare program in this country and to evaluate the feasibility of a new specific cost effective program and to improve management of sickle cell disease through early parental education and the institution of prophylaxis against infection.
RESULTS:
According to information obtained from the regional sources, our results indicate that the prevalence of SCD population was 0,022/1000 in 2011 versus 0,008/1000 in 1991; the SCD distribution is heterogeneous in the region. In the next 10 years, the annual incidence was augmented and the changing patterns of immigration, in particular recent African immigration, led to significant numbers of neonates at risk of sickle cell disease (70% of SCD population has not Italian origin or ethnicity). The current healthcare program assures a good survival and quality of life; the prevention program is not complete and neonatal newborn screening is not available but feasible.
CONCLUSIONS:
Our results are consistent with a changing of the sickle cell disease epidemiology in the Piedmont region with a specific regional distribution; a paucity of high-quality data limits appropriate estimation. The management of SCD requires a dedicated approach; this study support the notion that the healthcare for hemoglobinopathies can benefit from a specific prevention program as neonatal haemoglobinopathies newborn screening despite the logistic problems and economic constraints.
The development of prevention as the same time as specific clinical program is pivotal to improving SCD healthcare in this Italian region
Analisi teorica, numerica e sperimentale dei processi di grandi deformazioni nei materiali duttili
Get PDFA broad area of the troublesome bound to the mechanical design of structures is represented by the ability of including in the engineering analysis all the non linearity effects expressed by the ductile materials, often disregarded to obtain a clearer and simpler description of the phenomena. The frequently used “isotropic approach” and the choice of focusing only on the linear-elastic phase of the materials are the most important reasons behind the success of these design choices. Years after years, following the constant improvements in structures, in the material’s geometries and innovative shapes the designers are compelled to take into account all the situations in which the materials behave in a non-linear fashion, especially when they’re loaded with critical stress states.
Baseline or induced anisotropic phenomena, shear bandind, cinematic and isotropic hardening.,strain rate dependency, thermal effects, the loosing of the original mechanical
properties, are just a part of a bigger list of factors that affect the deformation properties of a body, leading to many complications in the theoretical analysis of solids and structures. To solve this problematic, the mathematical models used to include into the calculation the above cited effects (obtaining important results in terms of accuracy and reality of the description) lead to a much more complicate analytical formulation and a large increasing of all the experimental procedures connected with the parameters identification. Even if there’s an undeniable positive effect in the theoretical description of the material behavior and the phenomena investigated, on the other hand an important increase of all the numerical
and experimental costs and time consumption required is evident. Between all the possible non linearity effects in this thesis we focused only on the damage process and the anisotropic elasto-plasticity that, with no doubts, have a fundamental role to correctly modelling the ductile material behavior utilized in the gas/oil onshore and offshore pipelines. After a short historical review of the most important solutions that were presented in the
specialized literature, two different macro-mechanical damage model are analyzed in details: the the Lemaitre and Wierzbicki-Xue models. This choice was made to evaluate from different point of view the differences in the
determination procedures of the material features along the deformation pattern. Both the models were implemented and tested through two customized damage user-subroutines for the FE software Msc.Marc. The results obtained from the numerical simulations were checked using an optical method to evaluate the real displacement maps. The strain/
displacement maps were recorded in situ using a Digital Image Correlation technique on some particular aluminum specimens designed to highlight the inconsistencies of the two selected solutions. While the first part of the work only pertain to the ductile damage procedures, the second part of the thesis, is focused on the large strain formulation for elasto-plastic anisotropic solids: the
theoretical basis and the numerical algorithms are presented here and used to describe the constitutive relations for both the isotropic and anisotropic cases.
This background will be an essential part to essential part to move forward to "small deformation" case and introduce the Bathe-Montans plasticity model for the anisotropic solids. The Bathe-Montans model was implemented writing an UMAT subroutine for the FE code Abaqus Standard and numerically tested using different material and geometry/meshes. To validate the results, some numerical comparisons will be presented and moreover some numerical-experimental results obtained simulating particular classes of steel used in the onshore and offshore oil/gas pipeline will be shown to demonstrate the description ability and
the accuracy of the model proposed
Architettura e urbanità del turismo: il caso della Sardegna
Get PDFThe analysis of the relationship between architecture, the territory and modern tourism, the subject of this research, is part of the interpretation of the tourist phenomenon as a spatial phenomenon at the basis of new urban scenarios, capable of influencing the processes of the urbanization of places and their perception, of generating renewed urban metaphors contributing to modify social forms and methods of
communication. In this sense the initial frame of reference within which research is developed, refers to the theory of space aimed at understanding the phenomenon of tourism.The study of the “space tourist” has so far placed itself within the scientific debate regarding the geographical knowledge, of which two tasks have been traditionally assigned: the first was to provide representations, the second to translate the reading and interpretation of the territory into operational tools in order to transform it according to the needs of society. The latest spatial manifestations of tourism have therefore represented significant areas whereby to draft the features of a possible postmodern geography. But the analysis of space
tourism, in recent decades, has taken on a new dimension and with it, a new relevance in terms of social and cultural aspects, in fact tourist images of places have contributed in an ever more consistent way to feed the mind maps of individuals and thus their vision of space, of the
territory and of the world. The horizon of tourist research was broadened enormously by the research of the last ten ye-
ars, and tourism has thus become an important key for interpreting significant phenomena, starting with the process of nation building, the Americanization of consumer styles and production patterns, the elaboration of the con-
cept of heritage, the courses of development of backward economies, up until the most recent studies on the relationship between tourism and urbanism. And it is precisely on contemporary urban horizon which I intend to focus on in this work, thanks to more recent research trends of the French school, in particular in the transition
from the study of geography of tourism to the study of the relationship between tourism and urban themes and by the
research carried out by the MIT team (MIT Team – Mobilités, Itinéraires, Territoires). Today we can speak of hyper-tourist phase- a definition that may be useful to distinguish first generation tourism from the current one -
for the fact that the relationship which has been established between tourist industry, urban are as and local systems is typically post-modern. In fact, both in terms of territorial transformation and economic and cultural terms, many cities have taken tourism as the reference model and, in turn, tourist spots and places have
adopted dynamics which are typically urban even when pre-existing urban settlements are not mentioned. These premises are the basis of the objectives of this research that by analyzing the contemporary tourist phenomenon in its architectural and urban spatial dimension, intends to bring materials and methodologies for interpreting it
as a phenomenon that generates “urbanity”. The concept of urbanity thus allows us to approach tourism in a different way than just studying a set of practices which have incre-
ased exponentially: rural tourism, ecological tourism, seaside tourism, urban tourism, etc., allowing us to highlight the properties common to the tourist phenomenon and what forms it may take on. At the same time, the concept of urbanity allows us to bring out the urban characteristics produced through tourism. The concept of “urbanity” is then referred to the transformations of the territory tied to tourism: from the evolutionary trends of the settlement, which also fits the role and orientation of planning, up to the current processes of restructuring
the territory. In this sense it was deemed necessary to distinguish two reference scales: the extra-territorial dimension of the phenomenon where, in the dynamics of contemporary flows, it is possible to identify a sort of macroplace (destination) that includes all the spaces
where people come to and which they often share, and bringing us to a phenomenology of generalized de-localisation and de-territorialization.
- the territorial dimension, the one where in the concrete relationship with places, tourism leaves deep traces in space, produces urban substance becoming the generator of urbanity forms, which often defy the rules of the city in the consolidated or traditional sense, and for which it is necessary to define critical issues and politics of intervention . Starting from the need to bring the attention to the territorial dimension, in which analysis and formalization of the relationship between territory-tourism-urbanity can lead to theoretical and operational outcomes, the developments of this research thesis are then referred to the specific case study of Sardinia. This research is structured into three main sections. The first is dedicated to the analysis of space tourism, where, starting from the modern-post modern dichotomy as identified by Minca (1996), an in-depth examination is carried out, on the one hand, a kind of tourist space explo-
sion, with the acquisition of new and increasingly large territories and, on the other hand, a genuine tourist space implosion with the concentration inside closed or semi-closed areas in a series of images and pure, stylized tourist landscapes. The focus is placed on the territory: the tourist territory - namely the spatial organization (or
space-time) tourism, which presents itself since its origins as a consumer-driven system, because it is moulded favouring methods of access to resources and exchange, that today becomes the paroxysmal place of the flows both in terms of material consumption of goods – starting with the territory - in terms of geographical mobility (movement) and in terms of symbolic exchange (communication). The analysis of the first section focuses, as indicated in the introduction, focuses on the interpretation of the tourist phenomenon as a spatial phenomenon which causes space tran-
sformations through the construction of images and landscapes, creating forms of urbanity in terms of urban ‘products’ and architecture ‘products’. With reference to specific case studies and analysis we will then refer to the alternation in time of genuine models tied to the courses of differentiation and approval, related to the creation and organization of tourist area in which fundamental interpretations regard the formulations of Battilani (2007) and the research contribution of Trillo (2003). This type of analysis is supported by a further
comparison, the one with the specialised ‘manuals’ and its contents compared to the reflections and attempts to define guidelines for the space tourist project. Therefore those elements emerge - which is the basis and where the thesis is oriented towards with the ability to confer quality to the project of tourist spots, with a significant contribution in the Italian case, consisting of a lecture by Gio Ponti entitled “Architettura e turismo” (Architecture
and Tourism), held in 1942 for the Directorate General for tourism and ENIT (National Tourist Agency), which widens the horizon of the debate, from the manual type of debate to the more complex one: the context. The following paragraphs relate to a specific analysis of spatial transformations induced by tourism and in particular to the phenomena of cultural and physical de-location and de-territorialization, up to the analysis of urban dynamics-
related processes, in which often the concept of city is represented, made into a utopia, or subverted. If in the first section of the thesis tourism has been identified as a spatial phenomenon, which begins with a project, an intention tied to the use of places, it is evident to steer this research within a framework of analysis on the relationship between tourism and the theme of urban, introducing the second section with an interpretation of Tourism as a generator of urbanity. The possibility to analyze and identify the specific characters of urbanity, referring to the evolutionary dynamics of a given territory, can constitute a conceptual tool that allows us to receive the tourist dimension as a component of the ur-
ban aspect. This is formalized through the interpretation of
three different dimensions: that of urban monuments, urban public spaces and mobility, deepening the analysis on the relations between tourist spots and the differentials of urbanity, illustrating the issues whereby that tourist aspect is featured as “relative urbanity”. Consequently a second analysis scenario is introduced, the one that refers to the relationship between Tourists and Urbanists, hence
between tourism and planning. Some a few fundamental references, Oddi (2011) with regard to the study of the relationship between tourism and urban planning, we start with the fundamental differences that exist between the two scopes: the town is basically a technique and an art2 ; while tourism is – just as with all the “isms” - a movement, a flow, even before a pure and simple activity. In
this sense the town is the tourism object but it does not deplete its interests and interferes only partially with its reasons strongly tied to moving. That which unites urban planning and tourism, however, is the need for design, planning and programming of transformations that generate in the territory in order to ensure the control
and quality of interventions. It is clear that the town planning technique (more rarely art) has established the necessary instrument for implementing tourist settle-
ments, but the goals have strongly come apart, producing a sort of mutual distrust that under lies many still pervasive attitudes
Modelisation des aquiferes thermaux avec des methodes geophysiques integrees
Get PDFWritten work here was undertaken in order to investigate geothermal reservoirs associated with major faults, located in Caldes de Montbui, Spain, and Sardara, Sardinia. This thesis has two independent parts. The first is a theoretical profile of geophysical methods applied in this work. The second focuses on the development of a methodology for cross-validation between the electromagnetic model (EM), densities models, and models of resistivity. The development and application of this methodology were in two hydrothermal environments. To improve the knowledge of the structural context of thermal aquifers, different complementary techniques, audio magnetotelluric measures (AMT), Time Domain Electromagnetic (TDEM), Tomography of the electrical resistivity (ERT) and
Gravimetry, were made around the two areas of applications.
The important physical parameter identified by MT methods is the electrical resistivity, which is particularly sensitive to the presence and the mineralization of
the water. The three-dimensional modeling of the data allowed us to define the depth and the extent of hydrothermal levels. Despite some limitations, the MT method has proved well suited to study geothermal sites.
There are several geophysical methods that have become industry standards, but they should not be used in isolation. However, the resistivity method is very useful,
because it is directly related to the characteristics of geothermal reservoirs. In addition, because of the terrain of most geothermal areas and the profound nature of
the reservoir, the TDEM combined with MT resistivity methods are becoming the methods of choice for geothermal exploration
Il manuale del recupero dell'architettura storica dell'oasi di Figuig (Marocco): criticità e buone pratiche
Get PDFThe doctoral research “Manual for the conservation of the historical architecture of Figuig (Morocco)” has the goal to define for the individuation of best practices for the conservation and restoration of the earthen built heritage of the ancient city of Figuig in Morocco, an oasis on the edge Western Sahara, one of the most known and beloved in Morocco. The research, focused on the need to proceed with the proper conservation and restoration of built heritage, aims in the first place to highlight what are the meanings and characters of the built fabric of the oasis, individuating traditions, local materials and construction techniques, focusing on the problems that occur more frequently to the technicians responsible for their conservation and thus giving guidelines on good practices giving them elements for a proper approach to the renovation of the existent, not to obtain a conservation tout court of the ksar as historical monument, nor to promote the traditional model for new building, but to preserve a high quality building fabric restoring the texture and resolving the technical deficiencies and equipping it with modern facilities required by the contemporary model of life. The analysis of the town revealed the simplicity and ease of the construction methods used. An architecture that uses the few materials available on site with enabling technologies, leveraging the intrinsic characteristics of each material and element. The palm wood, very durable and enormously flexible, lime, derived from a plentiful and pure quality limestone, the soil, not particularly cohesive, but still suitable for the production of bricks; these materials, together, have contributed to build a coherent, effective and functional system. The solutions suggested as best practices derived from experiences already made in locations that have similar climatic conditions and characteristics of isolation, and are susceptible to insights that can be replicated in all the contexts of pre-Saharan area starting from the eastern Morocco, extending up to Libya and Egypt, countries that have, often also for coincidence of the founding peoples, very similar features in the settlement and its construction, and similar issues related to their conservation and regeneration. This research aims to represent an important data base for the definition of a theoretical and practical reference document at use for local administrations. Furthermore it represents a starting point for the compilation of more defined guidelines to favor a more correct use of the historical heritage and its proper maintenance, and propose methods of analysis of the urban fabric in order to operate consistently with the existing tissue. It is also more broadly aimed at "people". It is hoped that these tool will help to preserve the precious architectural legacy of earthen architecture Morocco and other nearby countries
Architectures and technologies for quality of service provisioning in next generation networks
Get PDFA NGN is a telecommunication network that differs from classical dedicated networks because of its capability to provide voice, video, data and cellular services on
the same infrastructure (Quadruple-Play). The ITU-T standardization body has defined the NGN architecture in three different and well-defined strata: the transport stratum which takes care of maintaining end-to-end connectivity, the service stratum that is responsible for enabling the creation and the delivery of services, and finally the application stratum where applications can be created and executed. The most important separation in this architecture is relative to transport and service stratum. The aim is to enable the flexibility to add, maintain and remove services without any impact on the transport layer; to enable the flexibility to add, maintain and remove transport technologies without any impact on the access to service, application, content and information; and finally the efficient cohesistence of multiple terminals, access
technologies and core transport technologies. The Service Oriented Architecture (SOA) is a paradigm often used in systems deployment and integration for organizing and utilizing distributed capabilities under the control of different ownership domains. In this thesis, the SOA technologies in network architetures are surveyed following the NGN functional architecture as defined by the ITU-T. Within each stratum, the main logical functions that
have been the subject of investigation according to a service-oriented approach have been highlighted. Moreover, a new definition of the NGN transport stratum functionalities according to the SOA paradigm is proposed; an implementation of the relevant services interfaces to analyze this approach with experimental results shows some insight on the potentialities of the proposed strategy.
Within NGN architectures research topic, especially in IP-based network architectures, Traffic Engineering (TE) is referred to as a set of policies and algorithms
aimed at balancing network traffic load so as to improve network resource utilization and guarantee the service specific end-to-end QoS. DS-TE technology extends TE
functionalities to a per-class basis implementation by introducing a higher level of traffic classification which associates to each class type (CT) a constraint on bandwidth
utilization. These constraints are set by defining and configuring a bandwidth constraint (BC) model whih drives resource utilization aiming to higher load balancing, higher QoS performance and lower call blocking rate. Default TE implementations relies on a centralized approach to bandwidth and routing management, that require external
management entities which periodically collect network status information and provide management actions. However, due to increasing network complexity, it is desiderable
that nodes automatically discover their environment, self-configure and update to adapt to changes. In this thesis the bandwidth management problem is approached adopting an autonomic and distributed approach. Each node has a self-management module, which monitors the unreserved bandwidth in adjacent nodes and adjusts the local bandwidth
constraints so as to reduce the differences in the unreserved bandwidth of neighbor nodes. With this distributed and autonomic algorithm, BC are dinamically modified to drive routing decision toward the traffic balancing respecting the QoS constraints for each
class-type traffic requests. Finally, Video on Demand (VoD) is a service that provides a video whenever the
customer requests it. Realizing a VoD system by means of the Internet network requires architectures tailored to video features such as guaranteed bandwidths and constrained
transmission delays: these are hard to be provided in the traditional Internet architecture that is not designed to provide an adequate quality of service (QoS) and quality of
experience (QoE) to the final user. Typical VoD solutions can be grouped in four categories: centralized, proxy-based, Content Delivery Network(CDN) and Hybrid
architectures. Hybrid architectures combine the employment of a centralized server with that of a Peer-to-peer (P2P) network. This approach can effectively reduce the server load and avoid network congestions close to the server site because the peers support the delivery of the video to other peers using a cache-and-relay strategy making use of their upload bandwidth. Anyway, in a peer-to-peer network each peer is free to join and leave the network without notice, bringing to the phenomena of peer churns. These dynamics are dangerous for VoD architectures, affecting the integrity and retainability of the service. In this thesis, a study aimed to evaluate the impact of the peer churn on the system performance is proposed. Starting from important relationships between system parameters such as playback buffer length, peer request rate, peer average lifetime and
server upload rate, four different analytic models are proposed
Definizione di una metodologia per l’implementazione di un sistema di aiuto alla decisione, in ambiente GIS, finalizzato all’integrazione dell’efficienza energetica degli edifici residenziali nei processi di formulazione e valutazione di politiche, piani o programmi in ambito urbano
Get PDFCon l’entrata in vigore del Protocollo di Kyoto1 e l’avvento delle recenti direttive comunitarie che
prevedono una drastica riduzione delle emissioni di GAS serra per il 20202, il tema dell’efficienza energetica
è diventato una delle priorità dei governi nazionali. Il settore residenziale, al quale nei paesi europei è riferibile circa il 40% delle emissioni, è uno dei settori strategici per il perseguimento dell’obiettivo comunitario.
Se da una parte le tecnologie esistenti rendono già possibile la realizzazione di nuovi edifici a consumo
quasi zero, nel declinare questo paradigma negli ambiti urbani consolidati si incontrano ancora notevoli difficoltà tecniche, normative e culturali. Dal punto di vista tecnico lo sviluppo delle nuove tecnologie in edifici già esistenti può semplicemente non essere possibile o può generare costi non proporzionati ai benefici; mentre sotto il profilo normativo si può scontrare con le istanze di tutela del paesaggio e dei beni culturali o con regolamenti edilizi non adeguati alle nuove esigenze. La tematica dell’efficienza energetica degli edifici può essere divisa in due filoni profondamente differenti per approccio e metodologie utilizzabili: il progetto di nuovi insediamenti ed il recupero del patrimonio esistente. I nuovi edifici, o la realizzazione ex novo di interi complessi, costituiscono un’occasione privilegiata per applicare i criteri di
sostenibilità energetica fin dalle prime fasi del progetto integrando le tecnologie disponibili in maniera ottimale. In questo caso il problema diventa squisitamente progettuale incentrandosi sulla sperimentazione di tecnologie e materiali o sullo studio di modelli insediativi sostenibili. Al contrario Il miglioramento della
sostenibilità del patrimonio edificato esistente non è solo una problematica di ottimizzazione tecnico-architettonica ma ha tutte le caratteristiche di un problema decisionale non strutturato3 che coinvolge a più livelli planner, decisori e cittadini. In questo caso, tanto i dati di input del problema, ossia lo stato attuale delle caratteristiche del patrimonio edificato, quanto le metodologie per la sua risoluzione hanno un forte grado di indeterminatezza; ciò rende difficile valutare tra diverse ipotesi di trasformazione urbana. Attualmente è possibile conoscere i consumi del settore residenziale ricavandoli dalle vendite di combustibile e dalle bollette, ma il dato non è sempre disponibile e comunque fornisce un’informazione aggregata alla scala urbana dalla quale non è possibile esplicitare direttamente i legami con le caratteristiche del patrimonio edificato. Al contrario, per definire efficacemente un programma di trasformazione urbana in chiave sostenibile, si ha la necessità di esplicitare le differenze che intercorrono tra le diverse parti della città. Il protocollo di Kyōto è stato sottoscritto nella città giapponese di Kyōto l'11 dicembre 1997 ed è entrato
ufficialmente in vigore il 16 febbraio 2005, dopo la ratifica anche da parte della Russia. I consumi reali del settore residenziale, ossia quelli misurati, non sono solo il risultato delle caratteristiche fisico-impiantistiche degli edifici, ma contengono una forte influenza della componente umana che con i suoi comportamenti incide notevolmente sul fabbisogno energetico. L’esplicitazione di questi due contributi è di primario interesse per la definizione mirata delle azioni rivolte alla parte fisica della città e per il progetto di efficaci campagne di educazione della cittadinanza. Per definire il fabbisogno energetico è necessario conoscere le caratteristiche fisico-geometriche degli edifici e quelle tecniche degli impianti; la mancanza di data base territoriali che possano fornire queste informazioni con completezza ed adeguato riferimento spaziale rende particolarmente difficile tracciare un
quadro della conoscenza sufficientemente rappresentativo della realtà. Esistono in letteratura più esperienze che utilizzano metodi analitici, statistici o misti per definire il fabbisogno energetico del patrimonio edificato in maniera funzionale ai propri scopi, ma tutte, per superare la forte indeterminatezza dei dati iniziali, compiono assunzioni e semplificazioni, più o meno arbitrarie, che ne limitano la precisione e l’utilità dei risultati. Nel recupero sostenibile del patrimonio costruito, la sostanziale mancanza dei dati di partenza e la difficoltà di comunicazione tra il sapere tecnico di alcuni portatori di interesse e quello, meno specialistico, di decisori e cittadinanza complicano il processo di sintesi della conoscenza che è alla base di un’azione di piano efficace. I decisori, perciò si trovano a dover effettuare scelte in contesti conflittuali, caricati di forti aspettative economiche e politiche, su aspetti di natura tecnica non sempre facilmente comprensibili ed integrabili con le tematiche tradizionalmente inerenti la pianificazione urbana. In questo quadro teorico lo studio si pone l’obiettivo di definire una metodologia per l’implementazione di un sistema di aiuto alla decisione finalizzato all’integrazione dell’efficienza energetica nei processi di formulazione e valutazione di politiche, piani o programmi di trasformazione urbana. Il cuore della metodologia è un tool GIS che, integrando i dati disponibili con l’apporto della conoscenza esperta degli attori del processo decisionale, è capace di calcolare il fabbisogno energetico del patrimonio edificato (calcolo Standard UNI 11300) e simulare gli effetti di possibili alternative progettuali contribuendo alla definizione del quadro della conoscenza del piano. Lo scopo non è tanto ottenere una stima accurata dei fabbisogni energetici, quanto proporre una procedura che, utilizzando il linguaggio ormai acquisito della Certificazione Energetica, sia di supporto a decisori ed esperti nella sintesi della conoscenza per la formulazione e la valutazione delle politiche urbane. Il lavoro di tesi si articolerà in tre parti:
la prima (Cap 1- Cap 5), a carattere più teorico, affronta alcuni temi che fanno da sfondo all’approccio
metodologico di questo lavoro, che, pur entrando in argomenti piuttosto tecnici, ha l’obiettivo di
2
fornire uno strumento utile alla costruzione della conoscenza condivisa in un processo decisionale
inerente le trasformazioni urbane in chiave di sostenibilità energetica;
la seconda (Cap 6-7), vero cuore dello studio, descrive come il metodo proposto possa sia definire lo Stato Attuale del patrimonio edificato, calcolandone i Fabbisogni netti e di Energia Primaria (calcolo standard della UNI 11300), che simulare scenari progettuali inerenti l’efficienza energetica degli edifici e la produzione energetica da FER.
la terza (Cap 8-9) riporta i risultati dell’applicazione della metodologia in un quartiere della città di
Cagliari al fine di mostrarne, seppur parzialmente, le potenzialità ed i limiti. Infine, nelle conclusioni, si accenna ad alcune interessanti prospettive di ricerca fortemente legate a questo lavoro
Development of new processes for ISRU (In Situ Resource Utilization) and ISFR (In Situ Fabrication and Repair) applications on Moon and Mars
Get PDFThe goal of this work is the development of new processes useful for future manned space missions, in the framework of the so-called ISRU (In-Situ Resource Utilization) and ISFR (In-Situ Fabrication and Repair) concepts. Specifically, the approach to ISRU will focus on
technologies necessary to extract consumables for human life-support system replenishment while ISFR is aimed to satisfy other human needs particularly related to the Fabrication Technologies, the Repair & Non Destructive Evaluation Technologies and the Habitat Structures.
After a introductory chapter, in the framework of ISRU and ISFR applications, a novel recently patented process based on the occurrence of Self-propagating High temperature Synthesis (SHS) reactions potentially exploitable for the in-situ fabrication of construction materials in Lunar and
Martian environments is described. The mixtures to be reacted by SHS are prepared taking advantage of the composition of lunar and martian regoliths. Lunar regolith simulant JSC-1A, Martian regolith JSC-1A, and Mojave martian regolith simulant are considered. In addition,
Aluminum is used as reducing agent for all systems examined, whereas ilmenite and iron oxides, namely ematite are added to the initial mixtures to be reacted in order to increase their exothermicity. It should be noted that both ilmenite and iron oxides are anyhow present in
significant quantities on Moon and Mars, respectively. The effect of starting mixture compositions on the self-propagating behaviour is examined under different gas pressures of the environment (atmospheric or vacuum) and gravity level (terrestrial or microgravity) and the
optimal experimental conditions are identified for each system investigated. The obtained products are characterized in view of their possible utilization as building materials. The final purpose is to allow manned space missions to extract and utilize in-situ resources necessary for human survival without being equipped with huge amount of supplies and to utilize specific
technologies to repair Lunar and/or Martian platforms also using in-situ materials, otherwise transported from the Earth. As it is apparent, the possibility to increase mission-time and economic aspects represents the main direct consequences
Insulino-resistenza: caratteristiche cardiometaboliche basali e dopo trattamento con Metformina ed esercizio fisico, da soli o in associazione
Get PDFInsulin resistance (IR) seems to play a major role both in the evolution towards diabetes, and in affecting myocardial performance and endothelial function. Has been showed
metformin (MET) therapy exert positive effect improving glucidic tolerance and preventing the evolution toward diabetes; nevertheless, it is known that MET may reduce maxVO2 consumption in an healthy population. Recently has been shown that adding metformin to exercise training did
not improve insulin sensitivity, and it may have blunted the full effects of exercise training. The aim of this study was to determine the effect of combining exercise training with metformin on cardiometabolic performance in individuals with IR, compared with either treatment alone.
Methods: out of population of 102 patients, 25 IR consecutive patients (9 females and 16 males; mean age 46±11 years) (HOMA=5±3.5) were enrolled to perform a cardiopulmonary exercise test and peripheral arterial tonometry, to measure the endothelial flow reserve (EFR), at baseline and after metformin. Insulin resistance was computed (HOMA-IR) before and after 12 weeks of each
intervention. The other IR patients were randomly assigned to metformin (M) (n=17), metformin with exercise training (ME) (n=11), and exercise training alone (E) (n =12 ). CPET (cardiopulmonary exercise test) and SF-36 to evaluate Health-Related Quallity of Life was performed at basal and after 12-weeks of treatment. Results: Mean value of VO2 peak at enrollment was reduced in comparison with the theoretic values of an healthy population (61,66 % ± 13).
Inter-test comparison performed at baseline and after 3 months of metformin revealed a slight reduction in BMI (29±5 vs 30±5, p<0.05), a significant increase in EFR (2.13±0.29 vs 1.93±0.44, p<0.05), and a significant reduction in VO2 (1.48±0.37 l/min vs 1.60±0.44 l/min, p=0.03). Nevertheless, the decline in peak VO2 was not displayed by the entire patient sample: 11 subjects
(group A) featured an increase in peak VO2, whilst 9 (group B) presented a decrease. A significant difference in HOMA index was detected between these 2 groups, with higher values in group A (7.8±3.5) than group B (3.3±0.7; p<0.001).
BMI was significantly reduced only in ME (31,5±4 vs 29,55±3,98; p<0,05) and M (29,75 ± 4,77 vs 28,4 ± 4,59; p<0,05) groups. CPET showed a significant increase of peakVO2 in E and ME whereas M showed no improvement of peak VO2 (∆ VO2 E +0,35 ± 0,46, p<0,05; ∆ VO2 ME +0,23 ± 0,31,
p<0,05; ∆ VO2 M -0,09 ± 0,13, p= < 0,05; M vs E p<0,01; M vs ME p<0,01; ME vs E p = ns). ME group showed a significant increase of Work compared respectively with M and E group (∆Work E +8,00 ± 16,42; ∆Work ME +23,00 ± 22,21; ∆Work M -2,92 ± 17,14; M vs E p=ns; M vs ME p<0,05, E
vs ME p=ns). SF-36 highlighted a significant increase in general Quallity of Life index in ME and E groups without differences between the two groups. Conclusions: Our study confirms that IR favors an impairment of cardiometabolic performance. The data obtained show that in IR patients metformin reduces average oxygen consumption to a
modest but significant extent. Indeed, it is of particular interest to observe how this effect was not manifested by all subjects, being present only in patients featuring a lower degree of IR, while patients with higher IR cardiopulmonary performance was significantly improved.
The negative effects showed by metformin therapy may be counterbalanced with the association of exercise training. Exercise training alone produced similar effects to the association of exercise training and Metformin in terms of cardiopulmonary performance and quality of life. The
additional benefits of improving effort tolerance and improving Health-Related Quallity of Life, contribute to identify the supervised training as a reliable and effective component in the management of IR population.
Therefore our conclusions are that the best treatment in IR patients is exercise training. More extensive studies are needed to show the real benefits of Metformin and exercise training association