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Direct evidence for abrupt rigidity and stress transitions in dry and homogeneous bulk Ge<sub>x</sub>Se<sub>100-x</sub> glassesBhosle, Siddhesh V. 04 August 2011 (has links)
No description available.
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College students’ intuitive understanding of the concept of limit and their level of reverse thinkingRoh, Kyeong Hah 10 October 2005 (has links)
No description available.
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Correlating Melt Dynamics with Glass Topological Phases in Especially Homogenized Equimolar GexAsxS100-2x Glasses using Raman Scattering, Modulated- Differential Scanning Calorimetry and Volumetric ExperimentsAlmutairi, Badriah Saad 27 September 2020 (has links)
No description available.
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Fronteiras do sertão baiano: 1640-1750 / Frontiers of the Bahia sertão : 1640-1750Santos, Marcio Roberto Alves dos 30 April 2010 (has links)
A análise histórica da formação territorial dos sertões brasileiros mostra que, diferentemente do que sugerem os estudos da primeira metade do século XX e mesmo perspectivas historiográficas mais recentes, o processo foi marcado por reversões, lacunas e descontinuidades que põem em xeque o modelo do território contínuo, da expansão geográfica e da dilatação das fronteiras. O principal objetivo deste trabalho foi superar esse modelo a partir da abordagem de situações de reversão da ocupação luso-brasileira do sertão baiano, assim entendido o conjunto espacial constituído, no período de 1640 a 1750, pelo interior da capitania da Bahia, Piauí, norte do atual estado de Minas Gerais e margem esquerda do médio São Francisco. Na problematização proposta foram utilizadas as categorias de descontinuidade e reversibilidade espaço-temporal da ocupação luso-brasileira. Para desenvolvê-la foi necessário rastrear a trajetória histórica das zonas de fronteira desse espaço interior, de modo a realçar o processo de formação do território luso-brasileiro como conquista e ocupação de antigos espaços tapuias. As zonas fronteiriças foram tratadas como áreas de fricção entre o instável território luso-brasileiro e os espaços nativos, sujeitas, portanto, à constante ameaça de retomada indígena ou de esvaziamento pelas pressões do meio. A mobilização da categoria de fronteira resultou em análises comparativas do espaço estudado com outras regiões fronteiriças e iluminou as possibilidades analíticas abertas pela aplicação dessa ferramenta teórica à compreensão da colonização luso-brasileira do interior da América portuguesa. Os fecundos resultados providos pela análise da ocorrência de expressões como fronteira, limite e última povoação na documentação consultada forneceram a garantia de que a fronteira foi um elemento histórico constitutivo da ocupação colonial dos sertões brasileiros. A utilização de metodologia de análise quantitativa de dados permitiu, por sua vez, o tratamento histórico das cinco principais estruturas de ocupação encontráveis nas zonas de fronteira do sertão baiano no período estudado: o caminho, a sesmaria, a povoação, o posto militar e a missão religiosa. A principal conclusão do estudo refere-se à abordagem da ocupação territorial dos sertões não como o avanço gradualmente positivado da civilização luso-brasileira, mas como uma trajetória multidirecional, descontínua e irregular. / The historical analysis of territorial formation of the Brazilian hinterlands shows that, unlike from what suggest the studies of the first half of the twentieth century and even more recent historiographical perspective, the process was marked by reversals, gaps and discontinuities that put into question the model of continuous territory, geographic expansion and expansion of the borders. The main objective of this work was to overcome this model through the approach of cases of reversal of the Luso-Brazilian occupation of Bahia sertão, understood as the whole space constituted, in the period from 1640 to 1750, of the interior of the captaincy of Bahia, Piauí, north of the current state of Minas Gerais and the left bank of the middle part of São Francisco. In the problem proposed have been used the categories of discontinuity and spatial-temporal reversibility of Luso-Brazilian occupation. To develop the problem, it has been necessary to trace the historical path of the frontier zones of that interior space in order to enhance the formation process of the Luso-Brazilian territory as conquest and occupation of former tapuias spaces. The frontier zones have been treated as friction areas between the unstable Luso-Brazilian territory and indigenous spaces, subject therefore to the constant threat of indigenous resumption or unsettlement because of the pressures of the environment. The mobilization of the category of frontier resulted in comparative analysis of the space studied with other frontier regions, and highlighted the analytical possibilities opened up by the application of this theoretical tool to understand the Luso-Brazilian colonization of the interior of Portuguese America. The fruitful results provided by the analysis of the occurrence of terms such as frontier, boundary and final settlement in the documents reviewed provided the guarantee that the frontier was a constitutive historic element of the colonial occupation of the Brazilian hinterlands. The use of methodology of quantitative analysis of the data allowed, in turn, the historical treatment of the five main structures of occupation findable in the frontier zones of Bahia sertão in the period studied: the way, the allotment, the village, the military outpost and the religious mission. The main conclusion of the study refers to the approach of territorial occupation of the hinterlands not like the gradually constituted advance of Luso-Brazilian civilization, but as a multidirectional, discontinuous and irregular path.
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Selection mechanisms for microstructures and reversible martensitic transformationsDella Porta, Francesco M. G. January 2018 (has links)
The work in this thesis is inspired by the fabrication of Zn<sub>45</sub>Au<sub>30</sub>Cu<sub>25</sub>. This is the first alloy undergoing ultra-reversible martensitic transformations and closely satisfying the cofactor conditions, particular conditions of geometric compatibility between phases, which were conjectured to influence reversibility. With the aim of better understanding reversibility, in this thesis we study the martensitic microstructures arising during thermal cycling in Zn<sub>45</sub>Au<sub>30</sub>Cu<sub>25</sub>, which are complex and different in every phase transformation cycle. Our study is developed in the context of continuum mechanics and nonlinear elasticity, and we use tools from nonlinear analysis. The first aim of this thesis is to advance our understanding of conditions of geometric compatibility between phases. To this end, first, we further investigate cofactor conditions and introduce a physically-based metric to measure how closely these are satisfied in real materials. Secondly, we introduce further conditions of compatibility and show that these are nearly satisfied by some twins in Zn<sub>45</sub>Au<sub>30</sub>Cu<sub>25</sub>. These might influence reversibility as they improve compatibility between high and low temperature phases. Martensitic phase transitions in Zn<sub>45</sub>Au<sub>30</sub>Cu<sub>25</sub> are a complex phenomenon, especially because the crystalline structure of the material changes from a cubic to a monoclinic symmetry, and hence the energy of the system has twelve wells. There exist infinitely many energy-minimising microstructures, limiting our understanding of the phenomenon as well as our ability to predict it. Therefore, the second aim of this thesis is to find criteria to select physically-relevant energy minimisers. We introduce two criteria or selection mechanisms. The first involves a moving mask approximation, which allows one to describe some experimental observations on the dynamics, while the second is based on using vanishing interface energy. The moving mask approximation reflects the idea of a moving curtain covering and uncovering microstructures during the phase transition, as appears to be the case for Zn<sub>45</sub>Au<sub>30</sub>Cu<sub>25</sub>, and many other materials during thermally induced transformations. We show that the moving mask approximation can be framed in the context of a model for the dynamics of nonlinear elastic bodies. We prove that every macroscopic deformation gradient satisfying the moving mask approximation must be of the form 1 + a(x) ⊗ n(x), for a.e. x. With regards to vanishing interface energy, we consider a one-dimensional energy functional with three wells, which simplifies the physically relevant model for martensitic transformations, but at the same time highlights some key issues. Our energy functional admits infinitely many minimising gradient Young measures, representing energy-minimising microstructures. In order to select the physically relevant ones, we show that minimisers of a regularised energy, where the second derivatives are penalised, generate a unique minimising gradient Young measure as the perturbation vanishes. The results developed in this thesis are motivated by the study of Zn<sub>45</sub>Au<sub>30</sub>Cu<sub>25</sub>, but their relevance is not limited to this material. The results on the cofactor conditions developed here can help for the understanding of new alloys undergoing ultra-reversible transformations, and as a guideline for the fabrication of future materials. Furthermore, the selection mechanisms studied in this work can be useful in selecting physically relevant microstructures not only in Zn<sub>45</sub>Au<sub>30</sub>Cu<sub>25</sub>, but also in other materials undergoing martensitic transformations, and other phenomena where pattern formation is observed.
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Fronteiras do sertão baiano: 1640-1750 / Frontiers of the Bahia sertão : 1640-1750Marcio Roberto Alves dos Santos 30 April 2010 (has links)
A análise histórica da formação territorial dos sertões brasileiros mostra que, diferentemente do que sugerem os estudos da primeira metade do século XX e mesmo perspectivas historiográficas mais recentes, o processo foi marcado por reversões, lacunas e descontinuidades que põem em xeque o modelo do território contínuo, da expansão geográfica e da dilatação das fronteiras. O principal objetivo deste trabalho foi superar esse modelo a partir da abordagem de situações de reversão da ocupação luso-brasileira do sertão baiano, assim entendido o conjunto espacial constituído, no período de 1640 a 1750, pelo interior da capitania da Bahia, Piauí, norte do atual estado de Minas Gerais e margem esquerda do médio São Francisco. Na problematização proposta foram utilizadas as categorias de descontinuidade e reversibilidade espaço-temporal da ocupação luso-brasileira. Para desenvolvê-la foi necessário rastrear a trajetória histórica das zonas de fronteira desse espaço interior, de modo a realçar o processo de formação do território luso-brasileiro como conquista e ocupação de antigos espaços tapuias. As zonas fronteiriças foram tratadas como áreas de fricção entre o instável território luso-brasileiro e os espaços nativos, sujeitas, portanto, à constante ameaça de retomada indígena ou de esvaziamento pelas pressões do meio. A mobilização da categoria de fronteira resultou em análises comparativas do espaço estudado com outras regiões fronteiriças e iluminou as possibilidades analíticas abertas pela aplicação dessa ferramenta teórica à compreensão da colonização luso-brasileira do interior da América portuguesa. Os fecundos resultados providos pela análise da ocorrência de expressões como fronteira, limite e última povoação na documentação consultada forneceram a garantia de que a fronteira foi um elemento histórico constitutivo da ocupação colonial dos sertões brasileiros. A utilização de metodologia de análise quantitativa de dados permitiu, por sua vez, o tratamento histórico das cinco principais estruturas de ocupação encontráveis nas zonas de fronteira do sertão baiano no período estudado: o caminho, a sesmaria, a povoação, o posto militar e a missão religiosa. A principal conclusão do estudo refere-se à abordagem da ocupação territorial dos sertões não como o avanço gradualmente positivado da civilização luso-brasileira, mas como uma trajetória multidirecional, descontínua e irregular. / The historical analysis of territorial formation of the Brazilian hinterlands shows that, unlike from what suggest the studies of the first half of the twentieth century and even more recent historiographical perspective, the process was marked by reversals, gaps and discontinuities that put into question the model of continuous territory, geographic expansion and expansion of the borders. The main objective of this work was to overcome this model through the approach of cases of reversal of the Luso-Brazilian occupation of Bahia sertão, understood as the whole space constituted, in the period from 1640 to 1750, of the interior of the captaincy of Bahia, Piauí, north of the current state of Minas Gerais and the left bank of the middle part of São Francisco. In the problem proposed have been used the categories of discontinuity and spatial-temporal reversibility of Luso-Brazilian occupation. To develop the problem, it has been necessary to trace the historical path of the frontier zones of that interior space in order to enhance the formation process of the Luso-Brazilian territory as conquest and occupation of former tapuias spaces. The frontier zones have been treated as friction areas between the unstable Luso-Brazilian territory and indigenous spaces, subject therefore to the constant threat of indigenous resumption or unsettlement because of the pressures of the environment. The mobilization of the category of frontier resulted in comparative analysis of the space studied with other frontier regions, and highlighted the analytical possibilities opened up by the application of this theoretical tool to understand the Luso-Brazilian colonization of the interior of Portuguese America. The fruitful results provided by the analysis of the occurrence of terms such as frontier, boundary and final settlement in the documents reviewed provided the guarantee that the frontier was a constitutive historic element of the colonial occupation of the Brazilian hinterlands. The use of methodology of quantitative analysis of the data allowed, in turn, the historical treatment of the five main structures of occupation findable in the frontier zones of Bahia sertão in the period studied: the way, the allotment, the village, the military outpost and the religious mission. The main conclusion of the study refers to the approach of territorial occupation of the hinterlands not like the gradually constituted advance of Luso-Brazilian civilization, but as a multidirectional, discontinuous and irregular path.
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Analyse de la notion de Décroissance sous l'angle de la théorie d'Économie Générale de Georges Bataille / An analysis of the notion of Degrowth from Georges Bataille’s theory of General EconomyHorrie, Anthony 28 June 2018 (has links)
Une opération économique, en fin de compte, repose sur une seule chose. Une chose des plus élémentaires qui soient, à savoir, tout simplement : l'emploi d'un objet. C'est bien là le socle de toute action économique. C'est-à-dire de toute action qui, à un moment donné, se veut utile ou rentable. Mais un tel acte a pour effet d'annuler toute la valeur que l'objet peut toujours présenter dans l'instant (comme son charme, sa drôlerie ou, encore, son étrangeté). Autrement dit, l'emploi d'un objet remplace toute la valeur sensible dudit objet par une valeur d'un autre ordre qui n'est autre que la valeur d'usage. Mais, le fait est qu'employer utilement quelque-chose n'a rien d'automatique. C'est qu'un tel acte revient très concrètement à s'opposer délibérément au cours habituel des choses qui, lui, consiste en une dépense inutile de chaque chose... Mais ce n'est pas tout car, au bout du compte, d'un point de vue général, l'action délibérée contre ce cours habituel des choses ne fait en réalité jamais que de l'accroître. Tout simplement parce qu'une telle action (n'étant donc pas automatique) se doit d'abord de dissiper pour son propre compte tout un tas de forces disponibles ; cela, avant même d'avoir pu commencer son œuvre. Tout ceci doit nous forcer à reconnaître que le véritable produit d'une opération économique n'est jamais qu'une meilleure dilapidation des richesses disponibles. Et c'est bien sous cet angle que sera envisagée, dans le cadre de ce travail, la notion de Décroissance. Cela grâce à la mise en perspective de la théorie d' « économie générale » de Georges Bataille avec les travaux de l'économiste Nicholas Georgescu-Roegen. / An economic operation relies, after all, upon one single thing. Upon one of the most elementary things, that is, simply: the use of an object. Such is the root of any economic act, i.e. of any act which, at some time, purports to be useful or profitable. But one effect entailed by such an act is to cancel all the value that such an object may instantaneoulsy present (such as its spell, drollery or, yet, its oddness). In other words, the use of an object implies that the sensitive value of that object be substituted by another sort of value, namely its use value. However, as a matter of fact, the useful employment of something is in no way automatic. Indeed, such a useful employment of things is actually equivalent to a deliberate opposition to the usual course of things, which consists, on the contrary, of a useless expenditure of all things... Still, from a general point of view, such a deliberate act against this usual course of things only achieves, after all, to always increase it. Just because such an act (thus, not being automatic), yet before it may have started to operate, first has to dissipate for itself a whole bunch of available forces. All of this leads us to acknowledge that the true product of an economic operation is always only a better squandering of the riches at disposal. It is according to this point of view that my research has focused on the notion of Degrowth, by combining Georges Bataille’s theory of “general economy” with economist Nicholas Georgescu-Roegen’s works.
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Antibiotic Resistance and Population Dynamics of Escherichia coli in Relation to a Large Scale Antibiotic Consumption InterventionSundqvist, Martin January 2010 (has links)
Antibiotic resistance challenges the practice and development of modern medicine. The aim of this thesis was to test the hypothesis that antibiotic resistance is reversible once the selection pressure of an antibiotic is removed. A decisive reduction (85%) in trimethoprim and trimethoprim-sulfamethoxazole over 24 months in Kronoberg County, Sweden, is described. The resistance baseline prior to the intervention and the effects of the intervention on resistance levels, trimethoprim resistance genes (dfr-genes) and population structure in Escherichia coli were studied. The effects of different algorithms for excluding patient duplicate isolates were small but systematic. An identical algorithm was used throughout. The drastic decrease in the use of trimethoprim containing drugs did not result in a corresponding decrease in trimethoprim resistance. This was true both for total trimethoprim resistance and for trimethoprim mono-resistance. The distributions of E. coli phenotypes, dfr-genes and E. coli sequence types were stable. The marginal effect on resistance rates was explained by a low fitness cost of trimethoprim resistance observed in vitro and the high levels of associated resistance in trimethoprim resistant isolates. Trimethoprim resistance was, although widespread in the E. coli population, more common in certain E. coli sequence types. The distributions of dfr-genes were different in E. coli and K. pneumoniae and between different E. coli sequence types. These results indicate mechanisms related to the genetic back-bone of E coli to be important for the acquisition and persistence of antibiotic resistance. The findings of this thesis indicates that, at least for some classes of antibiotics, we may have overestimated the usefulness of a strategy for reversing antimicrobial resistance based on the fitness cost of resistance. We have equally underestimated the conserving effects of associated resistance. The stability of the dfr-genes and E. coli sequence types underlines the importance of associated resistance and successful lineages in the spread and maintenance of antibiotic resistance in E. coli.
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Strategic Capacity Investment with Partial Reversibility under Uncertain Economic Condition and Oligopolistic CompetitionSim, Hee Jung 18 January 2005 (has links)
We consider the problem of capacity expansion in telecommunication networks under uncertain economic conditions with various market structures. We assume that the demands for network capacity have constant price-elasticity, and demand functions are parameterized by an economic condition that is modeled by a discrete time Markov process. We apply dynamic programming to obtain a state-dependent capacity expansion strategy that maximizes expected total discounted cash flow.
We incorporate partial reversibility of investment by differentiating the purchasing cost and the salvage value of the capacity. This partial reversibility makes the value function non-differentiable and divides the solution space into BUY, KEEP, and SELL regions. By identifying certain structural properties of the optimal solution, we perform sensitivity analyses on the optimal investment decisions with respect to market parameters. Under the condition that the level of cost depreciation is larger than that of the downside movement of the economic condition in each time period, we are able to obtain an analytical expression for the optimal capacity level and reduce the multi-period investment decision problem into a single-period myopic problem. As a result, optimal capacity increment depends only on the current economic condition.
We study this problem under both monopolistic and oligopolistic market structures. In particular, we investigate investment decisions by two firms in a duopoly setting with Cournot competition. We prove the existence and the uniqueness of the Cournot equilibrium strategies in the duopolistic capacity investment problem. In addition, we show how competition between firms affects total available capacity in the market, capacity price, consumer surplus, expected time to a certain level of price reduction, and expected time to the first investment.
We perform an empirical analysis to test a theoretical prediction obtained from our model through linear regression utilizing historical market data. By examining several alternative indices as a proxy to the economic condition considered in our model, we show that the Civilian Employment is the best proxy to use in validating the linear relationship between telecommunications capacity expansion and the economic indicator.
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When the Trees Look Back: Reversibility and the Genesis of Sense in Merleau-Ponty's Ontology of ArtHicks, Jeannette 02 January 2014 (has links)
Meaning or sense [sens] is traditionally thought to be bestowed by a subject, or found ready-made within the world. Against these views Merleau-Ponty develops an account of the genesis of sense in which it arises from the mutually formative relation between an intentionally directed body and the perceptual levels of the world. In this thesis I explore the implications of Merleau-Ponty's theory of sense for the work of art, arguing ultimately that artistic sense arises from a reversible relation between artist and world, intention and process, historical works and artistic goals, viewer and work. This account deepens through an analysis of the ontology of the Flesh through which we find that sense, as the intentional being of the body and the world, is what constitutes subject and object in the first place. Through a folding back on itself, being senses itself and gives rise to a generative difference through which new sense can emerge in perception, expression and aesthetic experience. / Social Sciences and Humanities Research Council of Canada (SSHRC) - Joseph-Armand Bombardier CGS Master’s, Ontario Graduate Fellowship (OGF)
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