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Garnet porphyroblasts are commonly used to determine P-T conditions in metamorphic rock assemblages. However, the actual process of porphyroblast nucleation is still poorly understood and garnet growth may occur at different conditions than those predicted by equilibrium thermodynamics. It is typically assumed that the Gibbs free energy of a system can be used to predict the growth of garnet at a given P and T, but here a new idea is proposed that in nature, growth does not occur until the chemical potential of each garnet-forming component departs from its equilibrium (pre-nucleation) state. Similar thermodynamic modeling results from a variety of metamorphic settings, rock types and apparent degrees of overstep indicate these deviations likely control the extent of overstep in the garnet-forming reaction in many natural samples. The process of metamorphic differentiation is then used to explain microstructures observed in the Haimanta Group, NW India that contain quartz-rich and mica-rich layers, with numerous garnet porphyroblasts appearing solely in the quartz-rich layers. This process is deformation-controlled, allowing the microstructures to be used as kinematic indicators to determine the deformation history of the Haimanta Group. The Elle Microstructural Modeling Program, the Basil deformation code and observed chemical zoning of garnets are used to prove metamorphic differentiation as the process responsible for garnet growth, meaning a singular, prograde event resulted in garnet growth in the Haimanta Group, in agreement with published monazite data for theses samples. / Master of Science

Obtemos propriedades de um modelo de rede para soluções diluídas de polímeros anfifílicos pequenos a partir do estudo das isotermas de potencial químico. Os resultados obtidos na rede de Bethe e em simulações de Monte Carla são apresentados. Introduzimos os cálculos na rede de Bethe através da mistura simétrica e estendemos o tratamento para dímeros, trímeros e tetrâmeros. O tratamento analítico também é generalizado para copolímeros com grau de polimerização arbitrário. As isotermas de potencial químico apresentam laços típicos de uma separação de fase macroscópica, muito embora se trate de um sistema em que duas densidades (anfifílicas livres e anfifílica na micela) coexistem em um sistema homogêneo. A partir destas isotermas, diagramas de fase são construídos. Nas simulações, propomos uma versão eficiente e revisada do \"teste de inserção\" de Widom. O método é inicialmente aplicado à mistura simétrica. Devido a problemas de tamanho finito, as isotermas de potencial químico indicam laços. Os laços podem ser associados a uma distribuição bimodal na curva distribuição de probabilidades no ensemble grande-canônico. Uma \"construção de Maxwell\" é aplicada nos dados, fornecendo uma curva de coexistência que converge rapidamente para a conhecida solução exata. A presença da coexistência de duas densidades é indicada por laços nas isotermas de potencial químico de soluções de anfifílicas pequenas. / We have obtained the properties of a lattice model for dilute solutions of short amphiphilic polymers from the study of chemical potential isotherms. Bethe lattice and Monte Carlo simulation results are presented. We introduce the Bethe lattice calculations for the symmetric mixture and apply them to dimers, trimers and tetramers. The analytic treatment is also generalized for a copolymer of arbitrary degree of polymerization. The chemical isotherms present loops typical of macroscopic phase separation, albeit for a system in which two densities (free amphiphile and amphiphile in micelle) coexist in a homogeneous system. Phase diagrams are presented. For the simulations, we propose a revised and efficient version of Widom\'s insertion test for mixtures. The method is tried on the symmetric mixture. The chemical potential isotherms present loops due to finite size effects. Loops can be associated with the double peak density probability in the grand-canonical ensemble. A \"Maxwell construction\" procedure yields a coexistence curve which converges rapidly to the known exact solution. Loops are present also in the case of short amphiphile solutions, indicating the presence of two densities.

Obtemos propriedades de um modelo de rede para soluções diluídas de polímeros anfifílicos pequenos a partir do estudo das isotermas de potencial químico. Os resultados obtidos na rede de Bethe e em simulações de Monte Carla são apresentados. Introduzimos os cálculos na rede de Bethe através da mistura simétrica e estendemos o tratamento para dímeros, trímeros e tetrâmeros. O tratamento analítico também é generalizado para copolímeros com grau de polimerização arbitrário. As isotermas de potencial químico apresentam laços típicos de uma separação de fase macroscópica, muito embora se trate de um sistema em que duas densidades (anfifílicas livres e anfifílica na micela) coexistem em um sistema homogêneo. A partir destas isotermas, diagramas de fase são construídos. Nas simulações, propomos uma versão eficiente e revisada do \"teste de inserção\" de Widom. O método é inicialmente aplicado à mistura simétrica. Devido a problemas de tamanho finito, as isotermas de potencial químico indicam laços. Os laços podem ser associados a uma distribuição bimodal na curva distribuição de probabilidades no ensemble grande-canônico. Uma \"construção de Maxwell\" é aplicada nos dados, fornecendo uma curva de coexistência que converge rapidamente para a conhecida solução exata. A presença da coexistência de duas densidades é indicada por laços nas isotermas de potencial químico de soluções de anfifílicas pequenas. / We have obtained the properties of a lattice model for dilute solutions of short amphiphilic polymers from the study of chemical potential isotherms. Bethe lattice and Monte Carlo simulation results are presented. We introduce the Bethe lattice calculations for the symmetric mixture and apply them to dimers, trimers and tetramers. The analytic treatment is also generalized for a copolymer of arbitrary degree of polymerization. The chemical isotherms present loops typical of macroscopic phase separation, albeit for a system in which two densities (free amphiphile and amphiphile in micelle) coexist in a homogeneous system. Phase diagrams are presented. For the simulations, we propose a revised and efficient version of Widom\'s insertion test for mixtures. The method is tried on the symmetric mixture. The chemical potential isotherms present loops due to finite size effects. Loops can be associated with the double peak density probability in the grand-canonical ensemble. A \"Maxwell construction\" procedure yields a coexistence curve which converges rapidly to the known exact solution. Loops are present also in the case of short amphiphile solutions, indicating the presence of two densities.

Nanoscale colloidal particles display fascinating electronic, optical and reinforcement properties as a consequence of their dimensions. Stable dispersions of nanoscale colloids find applications in drug delivery, biodiagnostics, photonic and electronic devices, and polymer nanocomposites. Most nanoparticles are unstable in dispersions and polymeric surfactants are added generally to improve dispersability and control self-assembly. However, the effect of polymeric modifiers on nanocolloid properties is poorly understood and design of modifiers is guided usually by empirical approaches. Monte Carlo simulations are used to gain a fundamental molecular-level understanding of the effect of modifiers properties on the thermodynamics and interaction forces of nanoscale colloidal particles. A novel method based on the expanded ensemble Monte Carlo technique has been developed for calculation of the chemical potential of colloidal particles in colloid-polymer mixtures (CPM). Using this method, the effect of molecular parameters like colloid diameter, polymer chain length, colloid-polymer interaction strength, and colloid and polymer concentrations, on the colloid chemical potential is investigated for both hard-sphere and attractive Lennard-Jones CPM. The presence of short-chain polymeric modifiers reduces the colloid chemical potential in attractive as well as athermal systems. In attractive CPM, there is a strong correlation between polymer adsorption and colloid chemical potential, as both show a similar dependence on the polymer molecular weight. Based on the simulation results, simple scaling relationships are proposed that capture the functional dependence of the thermodynamic properties on the molecular parameters. The polymer-induced interaction forces between the nanoparticles have been calculated as a function of the above parameters for freely-adsorbing and end-grafted homopolymer modifiers. The polymer-induced force profiles are used to identify design criteria for effective modifiers. Adsorbing modifiers give rise to attractive interactions between the nanoparticles over the whole parameter range explored in this study. Grafted surface modifiers lead to attraction or repulsion based on the polymer chain length and grafting density. The polymer-induced attraction in both adsorbing and grafted modifiers is attributed primarily to polymer intersegmental interactions and bridging. The location of the thermodynamic minimum corresponding to the equilibrium particle spacing in nanoparticle-polymer mixtures can be controlled by tuning the modifier properties.

In this thesis we use density functional theory (DFT) to study the solvent mediated interactions between solvophobic, solvophilic and patchy nanostructures namely rectangular cross section blocks. We calculate both the density profiles and local compressibility around the blocks and the results obtained for our model system provide a means to understanding the basic physics of solvent mediated interactions between nanostructures, and between objects such as proteins in water, that possess hydrophobic and hydrophilic patches. Our results give an improved understanding of the behaviour of liquids around solvophobic objects and solvophobicity (hydrophobicity) in general. Secondly, we look into the physics incorporated in standard mean-field DFT. This is normally derived by making what appears to be a rather drastic approximation for the two body density distribution function: ρ(2)(r,r′) ≈ ρ(r)ρ(r′), where ρ(r) is the one-body density distribution function. We provide a rationale for why the DFT often does better than this approximation would make you expect. Finally, we develop a lattice model to understand the nature of the pattern formation exhibited by certain systems of particles deposited on liquid-air interfaces and in particular the nature of the transitions between the different patterned structures that are observed. This is done using Monte Carlo computer simulations and DFT and links the observed microphase ordering with the micellisation process seen e.g. in surfactant systems.

Kyoto University (京都大学) / 0048 / 新制・課程博士 / 博士(工学) / 甲第14161号 / 工博第2995号 / 新制||工||1444(附属図書館) / 26467 / UT51-2008-N478 / 京都大学大学院工学研究科マイクロエンジニアリング専攻 / (主査)教授 立花 明知, 教授 榊 茂好, 教授 木村 健二 / 学位規則第4条第1項該当

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-03-30T17:53:42Z No. of bitstreams: 1 muiaraaparecidamoraes.pdf: 2242922 bytes, checksum: 649dffc13e33d3863587f15980f26e52 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-04-24T02:55:39Z (GMT) No. of bitstreams: 1 muiaraaparecidamoraes.pdf: 2242922 bytes, checksum: 649dffc13e33d3863587f15980f26e52 (MD5) / Made available in DSpace on 2016-04-24T02:55:39Z (GMT). No. of bitstreams: 1 muiaraaparecidamoraes.pdf: 2242922 bytes, checksum: 649dffc13e33d3863587f15980f26e52 (MD5) Previous issue date: 2013-07-19 / Palicourea rigida Kunth, pertencente à família Rubiaceae, têm sido utilizada na medicina popular para o tratamento de inflamação e infecção do trato urinário e do aparelho reprodutor feminino. O presente trabalho teve como objetivo avaliar o potencial químico-farmacológico de P. rigida e verificar a sua adequação aos padrões normativos do Sistema Único de Saúde (SUS). Folhas secas e pulverizadas foram submetidas à extração em etanol. Após remoção do solvente, extrato etanólico sofreu fracionamento por partição, produzindo as frações hexânica, diclorometânica, em acetato de etila e butanólica. Foram realizadas prospecção fitoquímica, quantificação de fenóis totais e flavonoides por espectrofotometria e análise por cromatografia líquida de alta eficiência. A atividade antioxidante foi avaliada pelos métodos do DPPH, bioautografia, poder de redução e -caroteno/ácido linoléico. A toxidez aguda foi determinada e as atividades antinociceptiva (testes de contorções, formalina e placa quente) e antiinflamatória (ensaios de edema de pata e pleurisia) foram realizadas. Análise da viabilidade da inclusão da P. rigida na lista de plantas de interesse ao SUS foi verificada. Os dados foram demonstrados através da média±erro padrão. Análise de variância seguida dos testes de Turkey ou Student-Newman-Keuls foram usados para medir o grau de significância para p < 0,05. Flavonoides, taninos, cumarinas, terpenoides e esteroides, alcaloides e antraquinonas foram detectadas em P. rigida. Os fenóis totais variaram entre 3,72 e 28,05 g/100 g, enquanto os flavonoides foram de 1,95 e 14,15 g/100g. Rutina e quercetina foram identificadas nas frações em acetato de etila e butanólica, respectivamente. Usando DPPH, as CE50 mostraram valores entre 24,51 ± 0,52 a 125,79 ± 0,10μg/mL, enquanto o poder de redução produziu CE50 de 183,09 ± 1,84 a 703,14 ± 1,15 μg/mL. As porcentagens de inibição da oxidação do -caroteno foram de 24,30 ± 3,38 a 84,76 ± 1,40. O extrato etanólico inibiu as contorções abdominais em 32,88 (100 mg/kg), 34,25 (200 mg/kg) e 61,64% (400 mg/kg). Doses de 200 e 400 mg/kg inibiram a primeira fase em 13,80 (200 mg/kg) e 24,74% (400 mg/kg), enquanto a segunda fase foi reduzida em 10,52 (100 mg/kg), 22,92 (200 mg/kg) e 35,73% (400 mg/kg). Após 90 min de tratamento, doses de 200 mg/kg (36,61%) e 400 mg/kg (71,21%) prolongaram o tempo de latência. Doses de 200 e 400 mg/kg reduziram o edema de pata após 3 e 4 h de tratamento. O volume do exsudato foi reduzido em 27,18 (200 mg/kg) e 36,89% (400 mg/kg) e o número de leucócitos totais sofreu inibição de 11,94 e 24,91% nas doses de 200 e 400 mg/kg, respectivamente. Os resultados indicaram que P. rigida constitui uma fonte promissora de substâncias bioativas com atividades antioxidante, antinociceptiva e anti-inflamatória, justificando o uso popular e reunindo características importantes de interesse do SUS. / Palicourea rigida Kunth, belonging to the family Rubiaceae, have been used in folk medicine for the treatment of inflammation and infection of the urinary tract and the female reproductive tract. This study aimed to evaluate the potential chemical-pharmacological P. rigida and verify its appropriateness to normative standards of the Unified Health System (SUS). Dried and sprayed leaves were extracted in ethanol. After removing the solvent, ethanol extract was submmited to the fractionation by partition to obtain the hexanic, dichlorometanic, in ethyl acetate and butanolic fractions. Phytochemical screening, quantification of total phenols and flavonoids by spectrophotometry and analysis by high performance liquid chromatography were performed. The antioxidant activity was evaluated by DPPH, bioautography, power reduction and -carotene/linoleic acid methods. Acute toxicity was determined and the antinociceptive (writhing, formalin and hot plate tests) and anti-inflammatory activities (paw edema and pleurisy methods) were evaluated. Analysis of the feasibility of inclusion of P. rigida in list of plants of interest to the SUS has been verified. Data were expressed by mean ± standard error. Analysis of variance followed by Turkey or Student-Newman-Keuls tests was used to measure the degree of significance to p < 0.05. Flavonoids, tannins, coumarins, terpenoids and steroids, alkaloids and anthraquinones were detected in P. rigida. The total phenols ranged between 3.72 and 28.05 g/100 g, while flavonoids were 1.95 and 14.15 g/100g. Rutin and quercetin were identified in ethyl acetate and butanolic fractions, respectively. Using DPPH, the values of EC50 showed between 24.51 ± 0.52 to 125.79 ± 0.10 mg/mL, while reducing power produced EC50 of 183.09 ± 1.84 to 703.14 ± 1.15 mg/mL. The percentages of inhibition of -carotene oxidation were 24.30 ± 3.38 to 84.76 ± 1.40. The ethanol extract inhibited the writhing at 32.88 (100 mg/kg), 34.25 (200 mg/kg) and 61.64% (400 mg/kg). Doses of 200 and 400 mg/kg inhibited the first phase in 13.80 (200 mg/kg) and 24.74% (400 mg/kg), while the second phase was reduced by 10.52 (100 mg / kg) , 22.92 (200 mg/kg) and 35.73% (400 mg/kg). After 90 min of treatment, doses of 200 mg/kg (36.61%) and 400 mg/kg (71.21%) prolonged the latency time. Doses of 200 and 400 mg/kg reduced the paw edema after 3 and 4 hours of treatment. The volume of exudate was reduced by 27.18 (200 mg/kg) and 36.89% (400 mg/kg) and total white cell count suffered inhibition of 11.94 and 24.91% at the doses of 200 and 400 mg/kg, respectively. The results indicated that P. rigida is a promising source of bioactive compounds with antioxidant, antinociceptive and anti-inflammatory activities that justifies the popular usage and gathers important characteristics of interest to the SUS.

No / We report a numerical calculation of the melting point of NaCl. The solid-liquid transition was located by determining the point where the chemical potentials of the solid and liquid phases intersect. To compute these chemical potentials, we made use of free energy calculations. For the solid phase the free energy was determined by thermodynamic integration from the Einstein crystal. For the liquid phase two distinct approaches were employed: one based on particle insertion and growth using the Kirkwood coupling parameter, and the other involving thermodynamic integration of the NaCl liquid to a Lennard-Jones fluid. The latter approach was found to be significantly more accurate. The coexistence point at 1074 K was characterized by a pressure of -30+/-40 MPa and a chemical potential of -97.9+/-0.2kßT. This result is remarkably good as the error bounds on the pressure enclose the expected coexistence pressure of about 0.1 MPa (ambient). Using the Clausius-Clapyron relation, we estimate that dP/dT~3 MPa/K. This yields a melting point of 1064+/-14 K at ambient pressure, which encompasses the quoted range for the experimental melting point (1072.45-1074.4 K). The good agreement with the experimental melting-point data provides additional evidence that the Tosi-Fumi model for NaCl is quite accurate. Our study illustrates that the melting point of an ionic system can be calculated accurately by employing a judicious combination of free energy techniques. The techniques used in this work can be directly extended to more complex, charged systems.

Cette thèse porte sur la physique statistique des systèmes hors d’équilibre maintenus dans un état stationnaire. Plus spécifiquement, ce travail s’intéresse à des quantités macroscopiques conservées (le volume, la masse, etc.) qui peuvent être échangées entre plusieurs systèmes hors d’équilibre en contact. Cette mise en contact d’un ou plusieurs systèmes est une situation fondamentale en thermodynamique classique des systèmes à l’équilibre, en ce qu’elle permet de définir la notion de paramètre thermodynamique conjugué comme la température, la pression, le potentiel chimique, etc., qui dérivent d’un même potentiel thermodynamique. Dans les systèmes hors d’équilibre stationnaires, l’existence de tels paramètres conjugués dérivant d’un potentiel thermodynamique (énergie libre) demeure une question ouverte. En se focalisant sur la situation du contact entre deux systèmes stochastiques hors d’équilibre quelconques de particules sur réseau dans des états homogènes, nous montrons l’existence d’une fonction de grande déviation attachée aux densités globales des deux systèmes, lorsque la fréquence d’échange de particules entre ces derniers est faible. Cette fonction de grandes déviations hors d'équilibre, analogue de l’énergie libre, vérifie une équation dite de Hamilton-Jacobi. Nous identifions les conditions naturelles pour lesquelles la fonction de grandes déviations est additive, menant ainsi à la définition de potentiels chimiques hors-équilibre. Néanmoins, nous montrons que ceux-ci dépendent de façon générique de la dynamique au contact et ne vérifient donc pas d’équation d’état. En l’absence de bilan détaillé macroscopique, l’équation de Hamilton-Jacobi est beaucoup plus difficile à résoudre. Une analyse perturbative par rapport aux forçages hors-équilibres permet de se convaincre que l’additivité est génériquement brisée dès les premiers ordres de perturbation en l’absence de bilan détaillé. Au-delà de la propriété d’additivité, cette fonction de grandes déviations peut être liée dans un certain nombre de cas au travail exercé par un potentiel extérieur à travers une relation de type second principe de la thermodynamique. Nous discutons également différentes façons d’y avoir accès expérimentalement.Fort de cette analyse théorique générale, nous illustrons celle-ci sur des systèmes stochastiques sur réseau classiques (Zero Range Process et Driven Lattice Gases) ainsi que sur un modèle de transport de masse original, exactement soluble. Nous appliquons également notre analyse sur des systèmes de particules auto-propulsées indépendantes. Dans chaque cas, l’importance du contact est alors pleinement révélée, en accord avec la littérature récente, que ce soit au niveau de la dynamique elle-même ou de la position de ce dernier vis-à-vis des systèmes. / This thesis deals with the statistical physics of out-of-equilibrium systems maintained in a steady state. More specifically, this work focuses on macroscopic conserved quantities (volume, mass, etc.) that can be exchanged between several out-of-equilibrium systems brought into contact. The contact between two systems is a fundamental situation in classical thermodynamics of equilibrium systems, since it allows one to define the notion of intensive thermodynamic parameter such as temperature, pressure, chemical potential, etc., derived from the same thermodynamic potential. For non-equilibrium steady state systems, the general existence of such intensive parameters remains an open issue. By focusing on the contact situation between two out-of-equilibrium stochastic systems on lattice in homogeneous states, we show the existence of a large deviation function attached to the overall densities of both systems, when the frequency of particle exchange between them is low. This large deviations function, analogous to a free energy, satisfies a so-called Hamilton-Jacobi equation. We identify the natural conditions for which the large deviation function is additive, leading to the definition of non-equilibrium chemical potentials. Nevertheless, we show that the latter generically depends on the contact dynamics and therefore do not obey any equation of state. In the absence of a macroscopic detailed balance, the Hamilton-Jacobi equation is much more difficult to solve. A perturbative analysis with respect to the driving forces allows one to show that additivity is generically broken. Beyond this additivity property, this large deviations function can – under certain assumptions – be related to the work applied by an external potential through a generalisation of the second law. We also discuss different ways to get access experimentally to this out-of-equilibrium free energy.Based on this general theoretical analysis, we eventually provide several illustrations on standard stochastic lattice models (Zero Range Process and Driven Lattice gases in particular) as well as a detailed analysis of an original, exactly solvable, mass transport model. Standard models of independent self-propelled particles are also discussed. The importance of the contact is eventually fully revealed, in agreement with recent literature, either in terms of the dynamics at contact itself or because of its position with respect to both systems.