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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
431

Characterisation, biophysical modelling and monetary valuation of urban nature-based solutions as a support tool for urban planning and landscape design

Babi Almenar, Javier 27 January 2021 (has links)
The recognition of nature in the resolution of societal challenges has been growing in relevance. This recognition has been associated with the development of new concepts from science and policy such as natural capital, ecosystem services, green infrastructure, and more recently Nature-Based Solutions (NBS). NBS intends to address societal challenges in an effective and adaptive form providing economic, social, and environmental benefits. The overall aim of this PhD thesis is to develop an environmental and economic assessment of NBS for highly urbanised territories based on rationales and models underpinning ecosystem services, urban/landscape ecology, and life cycle thinking approaches. This combined evaluation approach would help to better understand if NBS are cost-effective or not. The aim is developed according to four specific objectives. The first objective corresponds to the characterisation of NBS in relation to urban contexts and the problematics that they can help to address or mitigate. To achieve this objective a critical review on the study of the relationship between NBS, ecosystem services (ES) and urban challenges (UC) was developed. As a main output, a graph of plausible cause-effect relationships between NBS, ES and UC is obtained. The graph represents a first step to support sustainable urban planning, moving from problems (i.e. urban challenges) to actions (i.e. NBS) to resolutions (i.e. ES). The second objective corresponds to the definition of an adequate set of biophysical and monetary assessment methods and indicators to evaluate the value of NBS in urbanised contexts. To achieve this objective, a review of existing methods on ecosystem services valuation, life cycle cost analysis and life-cycle assessment are developed. The review takes into account specific constraints such as easiness to use and availability of data. At the end, potential methods and indicators were selected, which will be later integrated in the combined assessment framework. The third objective corresponds to the design of a combined assessment framework integrating methods from life cycle assessment, landscape/urban ecology and ecosystem services that quantifies the environmental and economic value of NBS informing about the cost-effectiveness of its entire life cycle. To achieve this objective, a conceptual framework is developed. From it, a system dynamics model of ecosystem (dis)services is developed and coupled with a life cycle assessment method. The combined evaluation is tested with a relevant NBS type (i.e. urban forest) in a case study in the metropolitan area of Madrid. The fourth objective is the development of a decision support (DSS) tool that integrates the assessment framework as part of iterative design processes in urban planning and landscape design. The DSS intends to enhance the interrelation between science, policy and planning/design. To achieve this objective a user-friendly web-based prototype DSS on NBS, called NBenefit$®, is developed. The prototype DSS provides the user a simple form of quantifying the provision of multiple ES and costs over the entire life cycle (implementation, operational life, and end-of-life) of NBS. This thesis contributed to the characterisation of NBS and its environmental and economic assessment to inform urban planning and landscape design processes, allowing decisions that are more informed. / Il riconoscimento della natura nella risoluzione delle sfide sociali è diventato sempre più importante. Questo riconoscimento è stato associato allo sviluppo di nuovi concetti provenienti dalla scienza e dalla politica, come il capitale naturale, i servizi ecosistemici, le infrastrutture verdi e, più recentemente, le soluzioni basate sulla natura (NBS). NBS intende affrontare le sfide della società in una forma efficace e adattabile fornendo benefici economici, sociali e ambientali. Lo scopo di ricerca di questa tesi di dottorato è quello di sviluppare una valutazione ambientale ed economica delle NBS per territori altamente urbanizzati basata su logiche e modelli che hanno alla base i servizi ecosistemici, l'ecologia urbana e paesaggistica e degli approcci di approcio life cycle. Questo quadro di valutazione combinato aiuterebbe a capire meglio se le NBS sono costo effetive e se contribuiscono a uno sviluppo resiliente e sostenibile. Questo scopo di ricerca è sviluppato secondo quattro obiettivi specifici. Il primo obiettivo corrisponde alla caratterizzazione delle NBS in relazione ai contesti urbani e alle problematiche che possono aiutare ad affrontare o mitigare. Per raggiungere questo obiettivo è stata sviluppata una revisione critica dell letteratura sullo studio della relazione tra NBS, servizi ecosistemici (ES) e sfide urbane (UC). Come risultato principale, si ottiene un grafico delle relazioni causa-effetto plausibili tra NBS, ES ed UC. Il grafico rappresenta un primo passo per supportare la pianificazione urbana sostenibile, passando dai problemi (es. UC) alle azioni (es. NBS) alle risoluzioni (es. ES). Il secondo obiettivo corrisponde alla definizione di un set di metodi e indicatori di valutazione biofisica e monetaria adeguate per valutare il valore della NBS in contesti urbanizzati. Per raggiungere questo obiettivo, viene sviluppata una revisione dei metodi esistenti sulla valutazione dei servizi ecosistemici, l'analisi dei costi del ciclo di vita e la valutazione del ciclo di vita. La revisione tiene conto di vincoli specifici come la facilità d'uso e la disponibilità dei dati. Alla fine, sono stati selezionati potenziali metodi e indicatori, che saranno successivamente integrati nel quadro di valutazione combinato. Il terzo obiettivo corrisponde alla progettazione del quadro di valutazione combinato, integrando metodi di valutazione del ciclo di vita, ecologia paesaggistica / urbana e servizi ecosistemici che quantifica il valore ambientale ed economico della NBS informando sull'efficacia in termini di costi del suo intero ciclo di vita. Per raggiungere questo obiettivo, prima viene sviluppato un quadro concettuale. Da esso, viene sviluppato un modello di dinamica di sistemi per calcolare i servizi (e disservici) ecosistemici, il quale è interrelazionato con un metodo di valutazione life cycle. Questa valutazione combinata viene testata con un tipo di NBS pertinente (foresta urbana) in un caso di studio nell'area metropolitana di Madrid. Il quarto obiettivo è lo sviluppo di uno strumento di supporto decisionale (DSS) che integri il quadro di valutazione come parte dei processi di progettazione iterativa nella pianificazione urbana e nella progettazione del paesaggio. Il DSS intende migliorare l'interrelazione tra scienza, politica e pianificazione / progettazione. Per raggiungere questo obiettivo è stato sviluppato Nbenefit$® un prototipo di DSS online per la valutazzione NBS di facile uso. Il prototipo DSS fornisce all'utente una forma semplice per quantificare multipli ES e costi (internalizatti o no) durante l'intero ciclo di vita (implementazione, vita operativa e fine vita) del NBS. In conclusione, questa tesi ha contribuito alla caratterizzazione di NBS e alla sua valutazione ambientale ed economica per informare i processi di pianificazione urbana e progettazione del paesaggio, consentendo decisioni più informate.
432

Theoretical and numerical models on the diffusive and hereditary properties of biological structures

Pollaci, Pietro January 2015 (has links)
The main bulk of this Thesis is focused on the response of cell membranes due to chemical and mechanical stimuli. Henceforth, it is mainly devoted to deduce how the key aspect of the cell response activated by chemical signaling can be predicted by a simplified energetics, making use of both theoretical models and numerical simulations. The a ention is focused on cell membranes embedding G protein-coupled receptors (GPRCs). By analyzing the behavior of cell mem- branes, one can isolate three main contributions in order to model their respon- se: (1) diffusion of receptors and transporters embedded in the lipid membrane; (2) conformational changes of the receptors; (3) membrane elasticity. Moreover, the interplay between TM confomational changes and lateral pressure of the lipid membrane against such TMs is introduced. The chemical potential of the receptor-ligand compound, deduced as the variational derivative of such energy, is compared with the one calculated by accounting for the work done by the lateral pressure. The result yields a relationship between the conformational field, the mechanical field (interpreted as either the thickness change or the areal change) and the distribution of the compounds receptor-ligand. The analysis of such resulting constitutive equation among those three quantities shows that, essentially, the reason why ligand-GPRCs compounds prefer to live on lipid ra is a necessity involving the interplay between the work performed by the lateral pressure and the need of TMs to change their conformation during ligand binding. Henceforth, mechanobiology gives a justification to the experimental findings of Kobilka and Lei ovitz, Chemistry Nobel Prizes 2012.
433

Theoretical and numerical tools for studying the Critical Zone from plot to catchments

Tubini, Niccolò 14 October 2021 (has links)
After the seminal works by Freeze and Harlan (1969), the scientific community realized that groundwater and vadose zone equation were breaking up. Hydrologists split into three communities following the motto “you are my boundary condition”: groundwater people, vadose zone scientists and surface water hydrologists. This compartmentalization of the scientific community fostered a deepening of knowledge in single branches, allowing to break things down into simple parts. However, this division represented an obstacle to the comprehension of the complexity that characterises the interactions between them. Eventually, this separation of the communities continued into software code. As a matter of fact, the boundary conditions were hard-wired, but they offered a poor representation of the physics in the interaction between different domains. Recently, there has been a renewed interest in studying the big picture, the interactions between different domains. This it is evident in the development of a new research field named the Earth’s Critical Zone (CZ). It is defined as the “ heterogeneous, near surface environment in which complex interactions involving rock, soil, water, air, and living organism regulate the natural habitat and determine the availability of life-sustaining resources” (National Research Council, 2001). Further interest in the studying the CZ is given by the ever-increasing pressure due to the growth in human population, wealth, and climatic changes. This thesis focuses on the CZ while recognising the central role of having a solid set of tools for modeling the water movements in all conditions. Recently, Prentice et al. (2015) identified Reliable, Robust, and Realistic, the three R’s, as the three characteristics that numerical models should have. Soil moisture is one of the key components to simulate the processes in the critical zone. The governing equation to describe the water flow in a porous material is know as the Richards equation and it dates back to 1931.The numerical solution of the Richards equation is far from trivial because of its mildly nonlinearity and it is often discarded in favour of more empirical models. After the pioneering work by Celia et al. (1990), a lot of work has been done in this direction and several model, for instance Hydrus, GEOtop, Cathy, Parflow adopted variants of the Newton algorithm to allows global convergence. Since Casulli and Zanolli (2010), anticipated by Brugnano and Casulli (2008), a new method called nested Newton has been found to guarantee convergence in any situation, even under the use of large time steps and grid sizes. The research presented in this thesis used this integration algorithm. Besides the numerical aspect, another issue was the correct definition of the boundary condition at the soil surface. As a matter of fact, the definition of the surface boundary condition is necessary to capture the generation of surface run-off. In the literature several approaches were proposed to couple surface and subsurface flow, and in this work the approach presented by Gugole (2016) has been used. The novelty regarded the discretization of the shallow water equation and the Richards equation in an unique algebraic system that was solved in a conservative manner. Richards equation was criticized from many points of view, but it is difficult to criticize its core mass conservation. The definition of the hydraulic properties of the soil, including both the soil water retention function (SWRC) and the hydraulic conductivity models, often uses simplified representation of the pore system describing it as bundle of cylindrical capillaries where the largest ones drain first and are filled last. As pointed out by Bachmann et al. (2002), “physical effects, like surface water film adsorption, capillary condensation and surface flow in liquid films, as well as volumetric changes of the pore space are often ignored”. Thus, the capillary bundle concept is a rough, even if still useful approximation of soil reality. From these observations, during the research the code has been designed to offer the opportunity to easily implement new soil water hydraulic models that might be proposed in the future. The Richards’ equation alone is not anymore sufficient to model the water flow in soils. In fact, soil temperature affects the water flow in soils. This is evident in cold regions where soil water is subject to freezing and thawing processes, but also in unfrozen soil, where temperature modifies water properties such as viscosity, the surface tension, and the contact angle. These microscopic variations of the water physical properties have significant impacts in the mass and energy budget within the CZ. For instance, it has been observed that the infiltration rates between the stream and the vadose zone show a clear diurnal pattern: infiltration rates are highest in late afternoon, when stream temperature is greatest, and they are lowest in early morning when stream temperature is least. In cold regions the run-off production is strongly affected by the presence of ice with the soil. Nonetheless, soil moisture modifies the thermal properties of the soil: water is characterised by a high thermal inertia and the thermal conductivity of ice is almost four times larger than that of liquid water, and water flow carries a significant amount of sensible heat. These aspects come under one the R of realistic. Hence, the Richards’ equation has been coupled with the energy equation for the unfrozen case. Moreover, the research developed a model to study the heat transfer considering the phase change of water. In both cases robust numerical schemes have been used. There are few models that already coupled the equations. One of these models is GEOtop that was conceived and built in the research group where this work was carried out. Such models have some limitations. One of the main limitations regards their implementations. In fact, these models were built as a monolithic code and this turns in difficulties in maintaining and developing existing codes. In this work the codes have been developed by using Design Patterns. As a result, the codes are easy to maintain, to extend, and to reuse. Considering the CZ, these aspects are of crucial importance. Researchers should have a model that can be extended to include more processes, i.e. increase its complexity and avoiding the code to become too complicated. The models were integrated in the Object Modelling System v3 (OMS3) framework. The system provides various components for precipitation treatment, radiation estimation in complex terrain, evaporation and transpiration that can be connected to each other’s for generating inputs and outputs. Due to the modularity of the system, whilst the components were developed and can be enhanced independently, they can be seamlessly used at run time by connecting them with the OMS3 DSL language based on Groovy. OMS3 provides the basic services and, among them, tools for calibration and implicit parallelization of component runs. In sum, the thesis analyses the relevant literature to date. It presents a detailed description of the physical processes related to the water flow and the energy budget within the soil. Then, it describes the numerical method used to solve and coupled the equations. It also provides the informatics behind WHETGEO 1D (Water HEat Tracers in GEOframe). Finally, the work focuses on the WHETGEO extension for the bidimensional case by showing how the code can be designed to store grid information.
434

Large strain computational modeling of high strain rate phenomena in perforating gun devices by Lagrangian/Eulerian FEM simulations

Gambirasio, Luca January 2013 (has links)
The present doctoral thesis deals with the study and the analysis of large strain and high strain rate behavior of materials and components. Theoretical, experimental and computational aspects are taken into consideration. Particular reference is made to the modeling of metallic materials, although other kinds of materials are considered as well. The work may be divided into three main parts. The first part of the work consists in a critical review of the constitutive modeling of materials subjected to large strains and high to very high strain rates. Specific attention is paid to the opportunity of adopting so-called strength models and equations of state. Damage and failure modeling is discussed as well. In this part, specific interest is addressed to reviewing the so-called Johnson-Cook strength model, by critically highlighting its positive and negative aspects. One of the main tackled issue consists in a reasoned assessment of the various procedures adoptable in order to calibrate the parameters of the model. This phase is enriched and clarified by applying different calibration strategies to a real case, i.e. the evaluation of the model parameters for a structural steel. The consequences determined by each calibration approach are then carefully evaluated and compared. The second part of the work aims at introducing a new strength model, that consists in a generalization of the Johnson-Cook model. The motivations for the introduction of this model are first exposed and discussed. The features of the new strength model are then described. Afterwards, the various procedures adoptable for the determination of the material parameters are presented. The new strength model is then applied to a real case, i.e. a structural steel as above, and the results are compared to those obtained from the original Johnson-Cook model. Comparing to that, the obtained outcomes show that the new model displays a better capacity in reproducing experimental data. Results are discussed and commented. The third and final part of the work deals with an application of the studied topics to a real industrial case of interest. A device called perforating gun is analyzed in its structural problematics and critical aspects. This challenging application involves the modeling of several typologies of material, large strains, very high strain rate phenomena, high temperatures, explosions, hypervelocity impacts, damage, fracture and phase changes. In this regard, computational applications of the studied theories are presented and their outcomes are assessed and discussed. Several finite element techniques are considered. In particular, tridimensional Eulerian simulations are presented. The obtained results appear to be very promising in terms of the possibilities of a fruitful use in the design process of the device, in particular in order to achieve an optimization of its key features.
435

Methods and Tools for Mainstreaming Nature-based Solutions in Urban Planning

Longato, Davide 12 July 2022 (has links)
This thesis addresses three interlinked aspects that are relevant for mainstreaming Nature-based Solutions in urban planning. The first aspect concerns the integration and use of ecosystem service knowledge in spatial planning. A literature review aimed at analysing practical applications of ecosystem services in real-life planning processes and instruments reveals both the outcomes generated and the procedures adopted to integrate them, as well as the main advantages, constraints, enabling factors, and open issues associated with ecosystem service knowledge integration in spatial planning processes and instruments. The second aspect is related to the use of spatial assessments of ecosystem service demand to support an effective planning of Nature-based Solutions at the city scale. An approach is developed to allocate and prioritize Nature-based Solutions in cities in order to deliver ecosystem services for addressing the existing urban challenges while maximising the benefits for residents. The approach is tested in the case study area of Valletta (Malta), identifying the potential sites for the implementation of eleven types of Nature-based Solutions, assessing the demand for five priority ecosystem services, and identifying what type(s) of Nature-based Solutions, among the eleven proposed, should be implemented in each potential site, as well as the sites that should be prioritized first. The third aspect involves the promotion of the implementation of Nature-based Solutions in urban plans through the use of suitable policy instruments. A matrix that links the suitable instruments identified to different typologies of Nature-based Solutions reveals the range of instruments that can be deployed to promote the implementation of each type of Nature-based Solution. The matrix is then applied to analyse which instruments are currently deployed and which are not in the two urban plans covering the case study area of Valletta, hence the missing opportunities that could be further exploited.
436

Computational models for impact mechanics and related protective materials and structures

Signetti, Stefano January 2017 (has links)
The mechanics of impacts is not yet well understood due to the complexity of materials behaviour under extreme stress and strain conditions and is thus of challenge for fundamental research, as well as relevant in several areas of applied sciences and engineering. The involved complex contact and strain-rate dependent phenomena include geometrical and materials non-linearities, such as wave and fracture propagation, plasticity, buckling, and friction. The theoretical description of such non-linearities has reached a level of advance maturity only singularly, but when coupled -due to the severe mathematical complexity- remains limited. Moreover, related experimental tests are difficult and expensive, and usually not able to quantify and discriminate between the phenomena involved. In this scenario, computational simulation emerges as a fundamental and complementary tool for the investigation of such otherwise intractable problems. The aim of this PhD research was the development and use of computational models to investigate the behaviour of materials and structures undergoing simultaneously extreme contact stresses and strain-rates, and at different size and time scales. We focused on basic concepts not yet understood, studying both engineering and bio-inspired solutions. In particular, the developed models were applied to the analysis and optimization of macroscopic composite and of 2D-materials-based multilayer armours, to the buckling-governed behaviour of aerographite tetrapods and of the related networks, and to the crushing behaviour under compression of modified honeycomb structures. As validation of the used approaches, numerical-experimental-analytical comparisons are also proposed for each case.
437

Extreme Terres of Anthropocene

Pasquali, Margherita 19 July 2023 (has links)
The contribution of this thesis aims to investigate the current state of vulnerability of Italian Innerlands, crossed by continuous phenomena and by discrete or sudden phenomena, to represent the tangible and intangible space to fully understand the performativity of these territories. The methodology used lies in an intermediate space between the values process of landscape ecology, which sees as its starting point the investigation of tangible land effects, and the quantitative-qualitative approach of mapping. A scale of values is assigned using GIS-assisted multi-criteria evaluation. The proposed methodology is set and applied in the case of Val di Sole, Trentino, to spatialise the relationship between risk and resources in Italian Innerlands. Extreme Terres of Anthropocene In the world of town planning, architecture, and landscape, searching for a new phenomenology is a way of interpreting and explaining how the great environmental, social, and economic changes the entire Earth System is undergoing are manifested in borderline contexts. Therefore, most ordinary human landscapes cannot be attributed to a single person. No one can be labelled for the responsibility of creating most ordinary landscapes, and there is rarely an identifiable person we can ask about the significance of these changes (Lewis 2003). Within the literature review of this research, a new phenomenology is constructed from the need to describe how reality presents itself and manifests itself in territories subject to constant change, the Extreme Terres. For these reasons, Part 1 focuses on the social, political, ecological, and environmental conditions that remained rather unquestioned as the concept of Extreme Terres. The aim is to understand the causes and consequences of ongoing transformations, with a focus on human impact on the soil. In today’s context, where the impact of man has led to a severe crisis experience the need arises to give a new meaning to the concept of Nature, which can no longer be considered mechanical, simple and above all objectively observable (Morin 2017;p.15), but Extreme. Today the difficulty of deciphering the meaning of extreme in ordinary landscapes is more complex than interpreting other types of historical documents. Looking outside the large population centres allows us to investigate urbanisation from the perspective of its supposed ‘outsiders’, the areas commonly represented as rural, remote, wild and/or untouched by human impact. In these places, described between literature and geography, morphologically isolated from the city, man exploits their land, which is the primary resource, choosing it as the raw material for production processes (Lefebvre 1974). The raw material, that is, the resource extracted, such as a mineral or water, has been exploited for years without giving it value in the production process; or even more simply, man has never bothered to give back what he received from the “terre”. Thus, these lands, which contain precious minerals, water sources, fertile soils, forests, and many other resources on the edge of the maximum risk, are named here as Extreme Terres. To understand the Extreme Terres, it is necessary to think of the boundary between the space of maximum urban expansion and what is uninhabitable for humans: the lands of production. These lands are fragile, and highly productive because they are rich in resources and subject to great instability. Inland or isolated lands in Italy, predominantly mountainous and hilly, are characterised by recurring geographical conditions and social-ecological processes. Common trends, such as depopulation and accelerated ageing of local communities, and divergent trends between abandonment or overexploitation of local resources are observed in these inner areas. In general, their relative geographic isolation makes them highly sensitive to discontinuities or disruptive events such as natural disasters (landslides, floods, flows disrupting connections) or the construction of large infrastructures (suddenly opening new flows). Where these territories are endowed with significant local resources and at the same time are extremely sensitive to discontinuities and changes, we call them ‘Extreme Terres’: where ‘great resources and great risks can evolve rapidly. In these territories, the condition of relative isolation with respect to more densely populated areas has an ambivalent or ambiguous value: the distance from urban centres and services exposes them to a greater risk of demographic decline, and the same distance limits exogenous pressures towards economic overexploitation of local resources and motivates their maintenance. Places in the extreme exist on the margins of the built world: they are found almost everywhere on the margins and in the interstices of residual and ambiguous cities (Barron and Mariani 2013). In this regard, Italy consists of a very long spine that is increasingly marginal and abandoned. People choose to live in cities and, when they choose towns, they always make sure they are comfortable and flat. Nobody wants to be in the most extreme place: the Apennines (Fig. 15-16). Part of the Italian territory of radiations and places that are in danger of being lost. In the extreme points of the territory, the Italian population has lived for millennia consuming what little was sufficient to sustain itself, and there are even areas where the landscape is still unspoilt. Moreover, the pandemic situation of recent years has influenced people’s values and priorities, allowing us to reconsider the value of lands outside urban centres. In Italy, overcoming a contrasting vision between cities and inland areas brings out a relationship of interdependence between territories, a fragile balance to be investigated and reconnected. In this context, this thesis proposes a reflection on the need to rethink the design of soil. This moves beyond the concept of urban or rural soil as opposed to nature and moves to a more inclusive definition that finds similarities with the word terre (Brenner.; Elden 2010). A fragmentation of multiple meanings around the concept of terre has appeared in the Italian landscape, by urbanism itself, as if it were “something taken for granted or having already included it in its genetic code without the need to return to it, to know well what it was” (Pileri, 2018). In order to respond to contemporary challenges, it is deemed appropriate to broaden the gaze beyond the modern city to a trans-scalar vision that includes the transformation dynamics of the marginal territories (Brenner, Schmid, 2014). Today we need to reverse the vision: no longer starting from the “centres” to the “peripheries,” but from the “margins” themselves. A new central idea is needed: that these are not places of consumption (of nature, traditions, etc.), but first and foremost territories of production, comprising new cultures, social innovations, techno-rural knowledge and practices, renewed ways of exercising welfare and interacting with the environment. The territories of the Italian inner areas, predominantly mountainous and hilly, are characterised by recurring geographical conditions and social-ecological processes. These inner areas have observed common trends, such as depopulation, accelerated ageing of local communities, and divergent trends between abandonment or overexploitation of local resources. In general, their relative geographic isolation makes them highly susceptible to discontinuities or disruptive events, such as natural disasters (landslides, floods, mudslides that disrupt connections) or the construction of large infrastructure (which suddenly opens new flows). In these territories, the condition of relative isolation from more densely populated areas has an ambivalent or ambiguous value: the distance from urban centres and services exposes them to a greater risk of demographic decline; the same distance limits exogenous pressures toward economic overexploitation of the local resources, and it motivates their maintenance. Research Question and Objective Why does man today still aspire to reach and exploit isolated lands when he is contributing to their disappearance?
This is the central question posed by the research “Extreme Terres of the Anthropocene” to understand the relationship between risk and resources in marginal lands. Specifically, in the Italian context, this contribution is supposed to understand the relationship between the risk and the resource of the territory in the Italian Innerlands and the effect that man has on these territories. Moreover, it also exists to ask what effect the flows of temporary or permanent inhabitants have onthese lands. This research hypothesizes that the existing condition of Extreme Terres has a potential value demonstrable through spatialization and design methodology. Research Aims and Objectives
The main aims of this contribution are to explain the condition of the Extreme Terres in the Anthropocene era; to explore and analyse the complexity of the Extreme Terres and to understand their value.
Therefore, this methodological research sets, as the main objective, mapping the condition of the Extreme Terres through a critical analysis of a selected application case in the Italian Innerlands. Methodological Approach The analytical reading of the Italian Innerlands proposed is based on the social, cultural, and natural geographical conditions of the terre. Therefore, the experimental model applied by Carlotta Olivari and Margherita Pasquali illustrated in the project “Yuxtaposiciòn Extrema” (Maggioli 2019) is taken up. Concerning the Italian inner areas’ spatialization, it becomes necessary to talk about Espace: “the attempt Extreme Terres of Anthropocene is to introduce spatial categories into social criticism.” (Olivari, Pasquali 2019; p.47). In the “Production of Space”, the architectural and urban space does not consider natural and social opacity. Within the proposed process, it is necessary to think about “the representations of space as imbued with the knowledge that is always relative and in transformation.” (Olivari, Pasquali 2019). In this contribution, geography and mapping are understood as tools for representing space and for understanding formation and development of the reference context. The effort is to include a multiscale analysis of the inner areas context through the mapping process. Methods of Investigation: Mapping as a Design Tool
Once the conceptual framework is stated, the methods of investigation need to be clarified. The goal is not to propose predefined solutions to the Italian Innerlands but rather to re-imagine fragmented and Extreme Terres via methodology to manage territorial uncertainty. The research methodology aims to respond to the endemic problems given by the conditions of risk, instability, and sudden changes to which different inner areas are subjected. Thus, the proposed methodology is structured on Italian Extreme Terres’ natural and anthropogenic conditions: the desire is to create a methodological approach to estimate the vulnerable marginal areas through a multi-scale and multi-level approach looking at fragmented territory. The aim is to underline the critical issues, potentiality, and sustainability of the Italian Innerlands space concerning the morphological conformation of the territory. Mapping is critically understood as an active and planning tool; the reading of these data can be used to highlight one or the other form, opening them up to narrative speculation. It is, therefore, a matter of critically reading geographical data and images and understanding what generates influences and composes them. Despite the attempt at mapping construction—dictated by incredible technical and logistical effort—the globe is more readable as an ongoing process of change than as an absolute, unchallenged object. By identifying the map as an active investigation tool, the cartographic inquiry is seen as a process of selection and as a potential and central tool in reading and interpreting the transformation of the land. For this reason, it is essential to work with “cognitive maps that can more effectively grasp the rapidly changing geographies of our planetary-urban existence” (Katsikis, Brenner 2013) to reach the capacity to reformulate what already exists (Corner 1999). More precisely, digital data processing is used, through the Geographic Information System (GIS) tool, the use of evaluating criteria and the classification of data and the zenith representation: the map. The Italian Innerlands, as a “geography of possibility”, are therefore semiotic and cognitive, as defined by Almo Farina, and not disconnected from the cultural context (Olivari, Pasquali, 2022) Results From the critical and theoretical reading of the context, Italian Innerlands appear a place at risk of depopulation and hydrogeological risk where tourism is used as an economic engine to exploit parts of the local landscape resources in places that were characterised by extractive processes for raw materials for production processes (energy, marble, minerals,water). Based on the parameters defined during the terre mapping methodology described at the beginning of the process, the mapping and data collection phase was characterised by in-depth research of information necessary to configure maps expressing the strong relationship between risk and resource in the Italian Innerlands. Through the mapping process, it is possible to highlight criticalities in a selected specific case, that of the Val di Sole and the smaller Val di Rabbi focus area: its existing resources and the presence of risk. The mapping process demonstrated and tested the interpretation of the potential of Extreme Terres in the marginal and alpine territory of Trentino, the one chosen as an ap- plication case. The description of the results obtained for the tangible mapping process of the Extreme Terres is the starting point for the subsequent phases of the doctoral research project that the “Extreme Terres of Anthropocene” thesis is pursuing. Discussion and Perspectives The conditions of environmental degradation and social vulnerability of the Italian Innerlands, especially the Val di Sole, are considered in this contribution as new opportunities: the slopes of the ravines become the perfect condition to recover and preserve the terre. Italian Innerlands must deal with instability, as they are situated in risky areas. As local populations live precariously and in continuous movement depending on the fickleness of nature in these areas, so the Italian Innerlands carry in them an awareness of their local knowledge as a “cultural landscape” (Farina 2000). Moreover, in these unstable conditions, “authorities managing risk could improve their strategic objectives if they could access and integrate” (Marten; Abrassart; Boano) Italian Innerlands in urban planning information. “Furthermore, a collaborative hazard governance can provide equity to multiple urban actors that are usually left out of institutional DRM, including nongovernmental organisations, academia, and community groups.” (Marten ; Abrassart ; Boano ). Thus, understanding the mixing of both nature and culture and ecology, territorial planning, and economic science allows us to create a model as a paradigm for ecological surveys and innovative management methods. Alternative models, such as cultural landscapes, should be integrated to address the contemporary overexploitation of resources and ongoing social imbalances. At the same time, a processual methodology is proposed to put these frameworks into a systemic approach that integrates economy with ecology and culture with nature. It is essential to consider the feasibility and eventual fallibility of the developed process (Olivari, Pasquali, 2022). From the point of view of the applicability of the proposed mapping methodology, we observe the necessity of understanding where the possible unbalances and richness of the territories involved come from. The capability of dialogue with the territorial planners, residents and workers using maps is essential to leave a tool to understand where and which ecological strategies should be proposed in such territories. Moreover, the proposed methodology is considered a process that cannot be replicated with actual results. Still, the conditions for establishing, each time, a new complex and endogenous thought are repeatable.
438

Ductility of cross-laminated timber buildings, influence of low-cycle fatigue strength and development of an innovative connection

Bezzi, Stefano 24 April 2020 (has links)
This thesis is mainly focused on the seismic behaviour of cross laminated timber (CLT) buildings. The document can be subdivided into three main sections closely related to each other. In the first part, after a short introduction on the state of the art on timber buildings regarding the constructive and legislative issues, the behaviour of CLT buildings is presented. The research is focused on the study on single shear-walls, on the multi-storey single-walls and on the behaviour of the whole buildings. The analyses are performed in order to assess the ductility level achievable by a CLT building as a result of different choices for the ductility of the connections at the foundation level. In order to estimate the ductility level, a large number of non-linear analyses were performed. This was possible thanks to a Matlab code, specifically developed, which allowed to reduce the computational burden. The results are used to evaluate a reliable set of behaviour factors to be applied in the seismic design of CLT buildings. In the second part of thesis, the low-cyclic fatigue strengths for different typologies of dissipative timber connections are presented. The low-cyclic fatigue strength represents a key-parameter in the assessment of the seismic behaviour of timber connections. In fact, high values of ductility associated with low values of strength degradation ensure a remarkable and reliable energy dissipation without a significant loss of strength. Despite the current version of chapter 8 of Eurocode 8 requires specific values of seismic demand for timber connections in terms of low-cyclic fatigue strength, no specific provision is reported to this regard in the European Standard for the cycling testing of timber connections and assemblage in seismic design (EN 12512). In This Standard the ductility capacity and the impairment of strength are calculated as separate mechanical parameters. For this reason, a proposal of revision of European Standard EN12512 is presented and discussed. The third and last part of the thesis describes an innovative connection for CLT buildings. This innovative connection was originally developed in order to absorb both traction and shear actions. Furthermore, a good performance has been obtained in terms of low-cyclic fatigue strength and ductility, with the aim of conceiving a connection able of satisfy the requirements of the current seismic European Standard. The design of this new connection was an iterative process, starting from some simplified numerical models. After some improvements, it was possible to obtain the expected performance levels. The strength and rigidity of the designed connection were initially obtained through numerical analysis, and then compared with the results of physical tests carried out in the Materials and Structures Testing Laboratory (MSTL), that is a part of the Department of Civil, Environmental and Mechanical Engineering (DICAM) of the University of Trento.
439

Interopérabilité de modèles dans le cycle de conception des systèmes électromagnétiques via des supports complémentaires : VHDL-AMS et composants logiciels ICAr / Interoperability of models in the design cycle of electromagnetic systems through complementary supports : VHDL-AMS language and ICAr software components

Rezgui, Abir 25 October 2012 (has links)
Cette thèse aborde les formalismes pour la modélisation multi-physique en support au cycle en V deconception. Ce travail a été réalisé dans le cadre du projet ANR–MoCoSyMec, selon la méthodologie duprototypage virtuel fonctionnel (PVF) et illustré sur des systèmes électromagnétiques.Nous nous sommes principalement intéressés au langage VHDL-AMS, en tant que support aux différentsniveaux de modélisation apparaissant dans le cycle en V de conception. Cela nous a conduits à traiter laportabilité et l’interopérabilité en VHDL-AMS de diverses méthodes et outils de modélisation. Nous avonsproposé et validé, via le formalisme des composants logiciels ICAr, des solutions aux limites de l’utilisation deVHDL-AMS pour modéliser certains phénomènes physiques reposants sur des calculs numériques.Nous avons étendu la norme ICAr pour supporter des modèles dynamiques décrits par des équationsdifférentielles algébriques (DAE) ; et pour des besoins de co-simulation, nous pouvons également y associer unsolveur. Ces développements sont désormais capitalisés dans le framework CADES.Enfin, nous avons proposé une architecture pour le portage de modèles d’un formalisme à un autre. Elle a étédéfinie et mise en oeuvre plus particulièrement pour des modèles magnétiques réluctants (Reluctool) et desMEMS magnétiques (MacMMems) vers le VHDL-AMS.Ces formalismes et méthodologies sont mis en oeuvre autour du PVF d’un contacteur électromagnétique. / This PhD report deals with modeling formalisms for multi-physical systems in the design V- cycle. Thiswork was carried out within the French ANR-MoCoSyMec project, according to the methodology of functionalvirtual prototyping (PVF) and illustrated with electromagnetical systems.The work focuses on the VHDL-AMS modeling language, as a support for several modeling levels appearingin the design V-cycle. In this work, the portability and interoperability problems have been studied, usingVHDL-AMS, for various modeling methods and tools. Solutions have been proposed and validated for use limitsof VHDL-AMS language, specifically for the modeling of some physical phenomena using numericalcomputations, through the software component formalism called ICAr.The ICAr software component standard has been extended to support dynamic models described throughdifferential algebraic equations (DAE). It has also been extended for co-simulation purposes in which a solver isassociated to the dynamic model inside the ICAr component. These developed solutions are now available in theframework CADES.Finally, architecture has been proposed for the transforming of models from a professional formalism intoanother, specifically into VHDL-AMS. It has been designed and implemented for reluctant magnetic models(RelucTool) and magnetic MEMS (MacMMems).These formalisms and methodologies are implemented around the functional virtual prototyping (PVF) of anelectromagnetic contactor.
440

EDILIZIA BASSOMEDIEVALE IN VAL CAVALLINA E NEL SEBINO BERGAMASCO: STUDIO CRONOTIPOLOGICO DEGLI ELEMENTI ARCHITETTONICI E DEI PARAMENTI MURARI

MATTEONI, FEDERICA BARBARA 08 March 2016 (has links)
Questo lavoro di ricerca ha come oggetto le architetture religiose, fortificate e civili di epoca bassomedievali conservate in Val Cavallina e sulla sponda occidentale del Sebino nella provincia orientale di Bergamo: questo territorio è privilegiato per la raccolta di dati utili alla definizione della seriazione cronotipologica degli elementi architettonici e dei paramenti murari datati tra XII e XV secolo. La redazione di tavole cronotipologiche è andata oltre l’aspetto tecnico, ma ha ricostruito i fenomeni sociali e politici di questo territorio in epoca bassomedievale: la costruzione dei castelli e delle torri condizionò la nuova rete insediativa dei borghi, definendo nuovi punti di aggregazione. Queste nuove costruzioni sono il riflesso di famiglie aristocrazie che utilizzano l’edilizia come strumento di affermazione di forza economica e potere sociale. L’analisi dei corpi di fabbrica condotto col metodo dell’archeologia dell’architettura ha consentito non solo la definizione delle tecniche edilizie, ma anche sulle dinamiche insediative nella provincia orientale di Bergamo. L’edilizia storica è fondamentale per comprendere i modi dell’abitare e di vivere: l’analisi di questi contesti ha consentito di distinguere specifiche tipologie abitative, e di ragionare sulle modalità occupazionali del territorio in epoca bassomedievale, riconoscendo per le due aree d’indagine peculiarità diverse. / This research is related to late medieval age religious, fortified and civil architecture preserved in Val Cavallina and on the western side of Iseo Lake, in the eastern province of Bergamo: this territory is privileged for the collection of data useful for the definition of the chrono-typological seriation of architectural elements and walls, dating from the twelfth and fifteenth centuries. Chrono-typological tablets exceed technical aspects, and reconstruct the social and political appearance of this territory in the late medieval age: the construction of castles and towers conditioned the new settlement of villages, setting new aggregation points. These new buildings are a reflection of aristocracy’s families, who builds as statement of economic and social power strength. The insight of the buildings made with the archeological method allowed the definition of building techniques, and the settlement dynamics in the eastern province of Bergamo. The historic building is crucial to understand the ways to live: the analysis of medieval buildings has allowed distinguishing specific typology of houses and the occupational way to set the territory in the late medieval age; every area has his architectural peculiarities.

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