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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.
11

Time-Reversible Maxwell's Demon

Skordos, P. A. 01 September 1992 (has links)
A time-reversible Maxwell's demon is demonstrated which creates a density difference between two chambers initialized to have equal density. The density difference is estimated theoretically and confirmed by computer simulations. It is found that the reversible Maxwell's demon compresses phase space volume even though its dynamics are time reversible. The significance of phase space volume compression in operating a microscopic heat engine is also discussed.
12

The Persistence of Spatial Mismatch: The Determinants of Moving Decision Among Low-Income Households

Anil, Bulent 13 January 2008 (has links)
This dissertation aims to investigate alternative explanations for the adjustment of low-income inner-city minorities to residential locations. Particularly, this study searches for an answer to find the reason why low-income inner-city minorities do not move to residential locations with more job opportunities (suburbs). Much of the basis for the analysis in this dissertation derives from the irreversible investment theory under the assumption that moving can be considered as an irreversible investment. First, this study formulates a search model in which individuals simultaneously search for jobs and residential locations in two places: suburb and inner-city. Second, by employing The Panel Study of Income Dynamics (PSID) and Geocode files, this study attempts to address how social capital plays a role in households’ moving decisions under the irreversibility assumption. This study presents evidence that the social capital has a negative causal effect on moving decision, that is, the high levels of social capital reduce the probability of moving.
13

Asset pricing implications of non-convex adjustment costs of investment /

Cooper, Ilan. January 2003 (has links) (PDF)
Ill., Univ. of Chicago, Graduate School of Business, Diss.--Chicago, 2003. / Kopie, ersch. im Verl. UMI, Ann Arbor, Mich.
14

Ετερογένεια του κεφαλαίου και αβεβαιότητα : μία εμπειρική προσέγγιση

Σακκάς, Γιώργος 14 February 2012 (has links)
Στη παρούσα εργασία θα εξετάσουμε το ζήτημα των επενδύσεων κάτω από καθεστώς αβεβαιότητας, καθώς επίσης και το πώς η μη αναστρεψιμότητα του κεφαλαίου επιδρά πάνω στη σχέση αυτή. Πιο συγκεκριμένα, θα εξετάσουμε πως η αβεβαιότητα επιδρά στην επένδυση ξεχωριστών τύπων κεφαλαίου, οι οποίοι χαρακτηρίζονται από διαφορετικό βαθμό μη αναστρεψιμότητας. / We examine the question of investment under conditions of uncertainty, and how the heterogeneity of capital affects this relationship. In particular, we will examine the impact of uncertainty on investment across types of capital, which are characterized by varying degree of irreversibility.
15

Otimização de um ciclo Brayton irreversível com regeneração, inter-resfriamento e reaquecimento através de uma função objetivo termoeconômica / Optimization of an irreversible regenerative, intercooled and reheated Brayton Cycle through a thermoeconomic objective function

Fornazari Filho, Ricieri 03 July 2018 (has links)
Submitted by Ricieri Fornazari Filho (ricieri.fornazari@gmail.com) on 2018-07-26T14:37:48Z No. of bitstreams: 1 Dissertação_Ricieri Fornazari Filho.pdf: 5238639 bytes, checksum: 37aec4ee567ed4046866f1a6f1be7a09 (MD5) / Approved for entry into archive by Lucilene Cordeiro da Silva Messias null (lubiblio@bauru.unesp.br) on 2018-07-30T13:52:12Z (GMT) No. of bitstreams: 1 fornazarifilho_r_me_bauru.pdf: 4325526 bytes, checksum: 1bd8c929f67ded30499ed09950b7e38e (MD5) / Made available in DSpace on 2018-07-30T13:52:12Z (GMT). No. of bitstreams: 1 fornazarifilho_r_me_bauru.pdf: 4325526 bytes, checksum: 1bd8c929f67ded30499ed09950b7e38e (MD5) Previous issue date: 2018-07-03 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Desenvolver e projetar plantas de potência otimizadas é uma constante e antiga busca da engenharia de energia. Para tal, os modelos de ciclos foram constantemente aprimorados ao longo do tempo. Através de estudos que procuram incorporar funções que descrevam a realidade mais precisamente, o equacionamento de irreversibilidades presentes nos processos e dispositivos reais de interações de trabalho e calor é vasto na literatura. Uma modelagem matemática foi desenvolvida para um ciclo Brayton irreversível com inter-resfriamento, regeneração e reaquecimento. As irreversibilidades consideradas são provenientes das resistências térmicas nos trocadores de calor do ciclo, do comportamento não isentrópicos dos elementos de expansão e compressão, da perda de calor para o reservatório frio e das perdas de carga nas tubulações ao longo do escoamento do fluido de trabalho. O método de otimização escolhido foi uma função termoeconômica a qual relaciona potência líquida com diversos tipos de custos de uma planta de potência, tais como custos de investimentos, de combustíveis, ambientais e de operação e manutenção. A modelagem matemática consistiu em determinar todas as temperaturas e parâmetros de interesse do ciclo através do conhecimento de apenas uma temperatura, denominada temperatura de controle. A partir de variações nesta temperatura foi possível estabelecer o comportamento dos demais parâmetros do ciclo e relacioná-los com irreversibilidades e parâmetros construtivos. O presente trabalho apresentou um modelo de ciclo Brayton não encontrado na literatura, acopladas diversas fontes de irreversibilidades sob a ótica de uma função de custos de quatro termos. Os resultados obtidos demonstram que a faixa ótima para operação em máxima potência difere da faixa ótima para operação sob máxima eficiência, sendo que a operação termoeconômica maximizada se aproxima mais da última do que da primeira. Foi observado também que as perdas de carga e as resistências dos trocadores de calor são irreversibilidades significativas no ciclo de potência. / Developing and designing optimized power plants is a constant and ancient search for energy engineering. For this, cycles models have been constantly improved over time. Through studies that seek to incorporate functions that describe the reality more precisely, the equating of irreversibility present in real processes and devices of work and heat transfer interactions is vast in the literature. A mathematical modeling has been developed for an irreversible Brayton cycle with inter-cooling, regeneration and reheating. The irreversibility considered are due to thermal resistances in the heat exchangers of the cycle, to the non-isentropic behavior of the elements for expansion and compression, to the heat loss to the could reservoir and to the head loss on the pipes along the working fluid flow. The optimization method chosen was a thermoeconomic function that relates the net power to various types of costs of a power plant, such as investment costs, fuel costs, environmental costs and operation and maintenance costs. The mathematical modeling consisted on determining all the cycle temperatures and parameters of interest through the knowledge of only one temperature, called control temperature. From variations in this temperature, it was possible to establish the behavior of the other parameters of the cycle and relate them to irreversibility and constructive parameters. The present work presented a model of Brayton cycle not found in the literature, coupled several sources of irreversibility under the optics of a four terms cost function. The results obtained demonstrate that the optimal operational range under maximum power differs from the optimal operational range under maximum efficiency, and the maximized thermoeconomic operation is closer to the latter than the first. It has also been observed that the head losses and the resistances in the heat exchangers are significant irreversibility in the power cycle.
16

Influence des propriétésdu graphite sur le premier cycle d'intercalation du lithium / Influence of graphite properties on the first cycle lithium intercalation

Bernardo, Philippe 05 July 2011 (has links)
Les batteries à ions lithium alimentent la plupart des petits appareils électriques, portables. Elles font usage du graphite comme électrode négative. Pour optimiser celle-ci, il faut réduire la perte spécifique de charge du premier cycle d’intercalation du lithium. Cette perte est principalement due à la formation d’une couche passive par décomposition de l’électrolyte. Les propriétés du graphite qui l’influencent sont partiellement connues. En particulier, une meilleure compréhension de l’exfoliation du graphite, responsable d’une grande perte spécifique de charge, est souhaitée. Ce phénomène est provoqué par la co-intercalation de solvant à travers les plans de bord des particules. Des paramètres comme la cristallinité, la chimie de surface et la réactivité du graphite semblent jouer un rôle. Une étude systématique a été entreprise afin de déterminer leur influence sur le premier cycle dans un électrolyte standard à base de carbonate d’éthylène et de diméthyle. Il apparaît que les complexes de surface oxygénés ne jouent pas de rôle particulier tandis que les complexes hydrogénés favorisent la co-intercalation de solvant. De plus, les graphites ayant une faible teneur en sites actifs constituant l’Active Surface Area (ASA), mesurée par chimisorption d’oxygène, sont plus enclins à exfolier. Comme les atomes de bord à deux voisins sont les plus réactifs en raison de la présence d’un électron célibataire, la plus grande sensibilité à la co-intercalation de solvant des graphites de faible ASA peut s’expliquer par la formation d’une couche passive inappropriée sur des plans de bord peu réactifs laissant passer le solvant. / In the field of small portable electrical devices, lithium-ion batteries are common. Graphite is used as the negative electrode. To improve its electrochemical performances, the first cycle specific charge loss must be decreased. It is predominantly attributed to the electrolyte reduction into a passivation layer. The graphite properties which influence this charge loss are not clearly identified. In particular, the graphite exfoliation which is responsible for a huge specific charge loss must be better understood. This dramatic phenomenon is due to solvent co-intercalation through the particle edge planes. Many graphite parameters such as crystallinity, surface chemistry and reactivity are thought to play a role. A systematic study was carried out in which the influence of each parameter on the first cycle was assessed in a standard ethylene and dimethyl carbonate based electrolyte. It appears that the presence of oxygen surface complexes does not have any influence whereas C6H bonds cause slight exfoliation. In addition, graphite samples containing low amount of active sites : the so-called Active Surface Area (ASA), quantified by oxygen chemisorption, are more likely to exfoliate. Since graphite active sites are mainly the edge atoms because of unpaired electron presence, low ASA graphite exfoliation can be explained by the formation of inappropriate passivation layer on the edge planes letting solvent molecules co-intercalate.
17

Game-Theoretic Approach to Thermodynamics / 熱力学へのゲーム論的アプローチ

Hiura, Ken 23 March 2022 (has links)
京都大学 / 新制・課程博士 / 博士(理学) / 甲第23691号 / 理博第4781号 / 新制||理||1684(附属図書館) / 京都大学大学院理学研究科物理学・宇宙物理学専攻 / (主査)教授 佐々 真一, 准教授 武末 真二, 講師 DECHANT Andreas / 学位規則第4条第1項該当 / Doctor of Science / Kyoto University / DFAM
18

Produção de entropia e comportamento crítico em modelos irreversíveis com simetria C3v / Entropy production and critical behavior in irreversible models with C3v symmetry

Bohorquez, Oscar Alberto Barbosa 11 May 2018 (has links)
A ênfase do trabalho recai na análise da taxa temporal de produção de entropia em sistemas de rede determinados por suas propriedades de simetria, no intuito de constituí-la como uma ferramenta paradigmática no estudo de sistemas irreversíveis. Nesse sentido, uma vez que se consegue consolidar uma definição consistente dessa grandeza para este campo, propõe-se uma abordagem estocástica para o modelamento da dinâmica dos exemplares considerados. O grupo de simetria C_ descreve as propriedades de invariância em sistemas com ampla relevância em física, de maneira que resulta natural elaborar a construção dos modelos em torno a sua estrutura, mais ainda quando se pode assumir que as características de simetria, no relativo à determinação da classe de universalidade dos modelos, são condições mais relevantes que a presença do não-equilíbrio, em coerência com a conjetura de Grinstein. Aliás, o modelo de Potts de três estados também apresenta propriedades de simetria próprias daquele grupo, além de ser passível de certo rigor no seu tratamento matemático, de maneira que oferece resultados consideravelmente satisfatórios e propícios para, por comparação, analisar os sistemas que concernem neste estudo. Assim, o procedimento tem como fim a determinação numérica da produção de entropia em sistemas com dinâmica irreversível e invariantes ante as transformações de simetria que compõem o grupo C_3v, partindo para isso de simulações de Monte Carlo em modelos estruturados sobre redes quadradas. A determinação da produção de entropia segue a prescrição de Schnakenberg (Schnakenberg [1976]), fundamentada nas correntes de probabilidade que surgem no sistema como consequência da violação da reversibilidade microscópica; a qual, por sua vez, estabelece a necessidade para os sistemas em equilíbrio de que todas as sequências cíclicas possíveis entre estados consecutivos sejam percorridas com igualdade de probabilidade num sentido quanto no inverso. Como uma segunda instância deste trabalho, também foram estudadas as propriedades de escalabilidade apresentadas por estos modelos durante seus primeiros instantes de evolução, isso, a partir da determinação numérica dos exponentes dinâmicos e sua caracterização dentro do marco teórico conhecido como \"short time scaling\'\' (Jansen et al. (1989)). Nesse sentido foram consideradas algumas das prescrições concernentes que tem apresentado melhor desempenho nos últimos anos. O observado mostra um comportamento coerente com a satisfação do que implicaria a conjetura de Grinstein para estes sistemas irreversíveis, indicando sua pertença à classe de universalidade do modelo de Potts de três estados, e, com isso, reafirmando os resultados obtidos em relação à produção de entropia. / This work is proposed as a study of the entropy production rate in lattice systems determined by its symmetries, looking for its consolidation as a paradigmatic tool in the area of irreversible and nonequilibrium systems. Henceforth, given the actual possibility of defining this quantity on that field, a stochastic perspective is adopted for modeling the dynamics of the considered systems. The C_ symmetry group describes the invariance properties of a wide range of physical systems, hence it results sensitive building the models to be dealt in accordance with its intrinsic characteristics, even more when it comes to be just fair, at the sight of the previous available analysis as well of the Grinstein conjecture, considering the invariance properties of systems as a more relevant factor than the reversibility conditions in what concerns the establishment of its universality class. The three states Potts model, indeed, shares its symmetry characteristics with those owned by the elements of the referred group and, also, concerning it there is a considerable amount of well confirmed information, becoming suitable for contrasting the results obtained. Henceforth, this work is focused on the numerical determination of the entropy production rate in irreversible systems whose invariance properties are the ones defined by the C_ symmetry group, implementing for that porpoise Monte Carlo simulations over square lattices models with the proper symmetries. By its own, the entropy production is determined in accordance with the Schnakenberg prescription (Scnhakenberg [1976]); deeply related with the probability currents emerging within irreversible systems as consequence of microscopic reversibility violation, which, in equilibrium, is imposed due to the mandatory equality between the evolution directions of all possible cyclic paths through a succession of states assumed by the system. As a second instance of this work, the scaling properties of the studied models during the first period of its evolution, just after the microscopic scale of time, were also analyzed. Henceforth, the determination of its dynamical exponents, as well as its characterization within the context of \"short time scaling\'\' (Jansent et al. [1989]) was realized through the calculus of some quantities with proven signatures of presenting an scalable \"initial slip\'\', finding strong suggestions for the models of being in the same universality class of the three state Potts model, fact coherent with the Grinstein conjecture if extended over them, but also with the observed behavior of the entropy production.
19

Irreversibilidade por competição para um modelo de Glauber-Ising a partir da produção de entropia / Irreversibility by competition for a Glauber-Ising model by means of the entropy production

Bohorquez, Oscar Alberto Barbosa 18 December 2012 (has links)
Trata-se um sistema irreversível e fora do equilíbrio adotando uma dinâmica estocástica, a partir de uma abordagem que visa a compreensão dos efeitos macroscópicos como uma consequência das características microscópicas do sistema. O estudo enfoca-se sobre as transições de fase cinéticas que têm lugar pela adoção de um modelo de rede, no intuito de descrever os estados estacionários por meio da produção de entropia, que caracteriza o comportamento do sistema elucidando as suas condições de reversibilidade. Dessa forma considera-se um modelo de Ising cinético com simetria \\textit{up-down} e sob a influência de duas dinâmicas de Glauber em competição. Nesse sentido considera-se uma rede quadrada constituída por duas subredes atreladas, as quais submetem-se ao contato de reservatórios térmicos a diferentes temperaturas. O estudo é feito mediante a adoção de uma abordagem analítica assumindo uma aproximação de campo médio, e, do mesmo modo, com base em resultados de caráter numérico obtidos com simulações de Monte Carlo. Os resultados mostram uma transição de fase de segunda ordem no regime de não equilíbrio, a qual é refletida numa divergência logarítmica na derivada da produção de entropia. / An irreversible and out of equilibrium system is analyzed by means of a stochastic dynamics based on an approach that aims to understand the macroscopic effects as a consequence of the microscopic characteristics. The study focus on the kinetic phase transitions that take place by assuming a lattice model, intended to describe the stationary states by the entropy production, which characterize the system behavior, clarifying the reversibility conditions. Thus a kinetic Ising model with up-down symmetry and under the influence of two competing Glauber dynamics is analized. In this sense one considers a square lattice formed by two sublattices interconnected, which are in contact with two heat baths at different temperatures. The study is made by means of the analytical approach of a mean-field approximation and Monte Carlo simulations. The results show a phase transition of the second order in the steady state regime, which is evidenced by a logarithmic divergence of the entropy production derivative.
20

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 Economy

Horrie, 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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