Made available in DSpace on 2014-06-11T19:26:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2005-12-16Bitstream added on 2014-06-13T18:06:54Z : No. of bitstreams: 1 melo_fd_me_sjrp.pdf: 346555 bytes, checksum: ff1f3651e3e5a108fe83b33dbae4e46b (MD5) / O principal objetivo deste trabalho é calcular a densidade de centro da representação geométrica do ideal totalmente ramificado em corpos de condutor primo. Primeiro, fazemos a caracterização dos subcorpos do p-ésimo corpo ciclotômico e dos elementos do ideal, também calculamos a norma desse ideal. Em seguida, é apresentada uma forma quadrática e explicitado o seu mínimo para o cálculo do raio de empacotamento dessa representação geométrica. Finalizamos com o cálculo da densidade de centro. / The main aim of this work is to calculate density of the center from the geometric representation of the totally ramified ideal in prime conductor fields. First of all, we make the characterization of the elements from subfields of the p-th cyclotomic field and from the ideal of the elements, we also calculate the norm of this ideal. After that, a quadratic form is presented and exhibit its minimun for the radius of packing calculation this geometric representation. Concluding with the center density calculation.

Made available in DSpace on 2014-06-11T19:26:56Z (GMT). No. of bitstreams: 0 Previous issue date: 2003-07-18Bitstream added on 2014-06-13T18:06:55Z : No. of bitstreams: 1 rodrigues_tm_me_sjrp.pdf: 669881 bytes, checksum: d646ae2e14ccda760ac3fe6d775927d1 (MD5) / O propósito deste trabalho é abordar as cúbicas galoisianas as quais, pelo Teorema de Kronecker-Weber, estão contidas em uma extensão ciclotômica Q(dn), para algum n. Estudamos a representação geométrica do seu anel dos inteiros algébricos, que são reticulados de posto 3. Visando calcular a densidade de centro de tais reticulados, é necessário o estudo do discriminante dessas cúbicas e a minimização da função traço. / The purpose of this work is to deal with the galoisian cubics which, by Kronecker-Weber Theorem, are contained in a cyclotomic extension Q(dn); for some n. We study the geometric representation of their algebraic integer ring, which are lattices with rank 3. For calculating the center density of these lattices, it is necessary to study the discriminant of those cubics and the minimization of trace form.

The recent development of a framework called non-affine lattice dynamics made it possible to calculate the elastic moduli of disordered systems directly from their microscopic structure and potential energy landscape at zero temperature. In this thesis different types of disordered systems were studied using this framework. By comparing the shear modulus and vibrational properties of nearest neighbour spring networks based on depleted lattices we were able to show that the dominating quantity of the system’s non-affine reorganisation during shear deformation is the affine force field. Furthermore we found that different implementation of disorder lead to the same behaviour at the isostatic point. Later we studied the effect of long range interaction in such depleted lattices with regard to spatial correlation local elasticity. We found that the implementation of long springs with decaying spring constant reproduced the spatial correlation observed in simulations of Lennard-Jones glasses. Finally we looked at simple freely rotating polymer model chains by extending the framework to angular forces and studied the dependence of the shear modulus and the vibrational density of states (VDOS) and length and bending stiffness of the chains. We found that the effect of chain length on the shear modulus and the vibrational density of states diminishes as it depends on the number of backbone bonds in the system. This number increases fast for short chains as many new backbone bonds are introduced but slows down significantly when the chain length reaches 50 monomers per chain. For the dependence on the bending stiffness we found a rich phenomenology that can be understood by looking at specific motions of the monomers relative the the chain geometry. We were able to trace back the different regimes of the VDOS to the simple model of the triatomic molecule. We also explored the limits of non-affine lattice dynamics when describing systems at temperatures T > 0 and gave an approximate solution for the shear modulus in this case.

The polaron problem is studied, on an infinite lattice, using the continuous-time path-integral quantum Monte Carlo scheme The method is based on the Feynman technique to analytically integrate out the phonon degrees of freedom. The transformed problem is that of a single electron with retarded self-interaction in imaginary time. The Metropolis algorithm is used to sample an ensemble of electron trajectories with twisted (rather than periodic) boundary conditions in imaginary time, which allows dynamic properties of the system to by measured directly. The method is numerically "exact", in the sense that there are no systematic errors due to finite system size, trotter decomposition or finite temperature The implementation of the algorithm in continuous imaginary time dramatically increases computational efficiency compared with the traditional discrete imaginary time algorithms.

abstract: Environmentally responsive microgels have drawn significant attention due to their intrinsic ability to change volume in response to various external stimuli such as pH, temperature, osmotic pressure, or electric and magnetic fields. The extent of particle swelling is controlled by the nature of the polymer-solvent interaction. This thesis focuses on design and synthesis of environmentally responsive microgels and their composites, and encompasses methods of utilizing microgel systems in applications as vehicles for the adsorption, retention, and targeted delivery of chemical species. Furthermore, self-assembled microgel particles at ionic liquid (IL)-water interfaces demonstrate responsive colloidal lattice morphology. The thesis first reports on the fundamental aspects of synthesis, functionalization, and characteristic properties of multifunctional environmentally responsive microgels derived from poly(N-isopropylacrylamide) (PNIPAm) and other functional co-monomers. In particular, the uptake and release of active chemical species such as rheology modifiers into and from these ionic microgels is demonstrated. Moreover, a facile tunable method for the formation of organic-inorganic composites with Fe3O4 nanoparticles adsorbed and embedded within ionic microgel particles is explored. Additionally, the development of zwitterionic microgels (ZI-MG) is presented. These aqueous ZI-MG dispersions exhibit reversible parabolic swelling as a function of pH and display a minimum hydrodynamic diameter at a tunable isoelectric point (IEP). This study also elucidates the controlled uptake and release of surfactants from these particle systems. The extent of surfactant loading and the ensuing relative swelling/deswelling behaviors within the polymer networks are explained in terms of their binding interactions. The latter part of this thesis highlights the versatility of fluorescently labeled microgel particles as stabilizers for IL-water droplets. When the prepared particles form monolayers and equilibrate at the liquid-liquid interface, the colloidal lattice organization may re-order itself depending on the surface charge of these particles. Finally, it is shown that the spontaneously formed and densely packed layers of microgel particles can be employed for extraction applications, as the interface remains permeable to small active species. / Dissertation/Thesis / Doctoral Dissertation Chemical Engineering 2015

Made available in DSpace on 2014-10-09T12:35:01Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T14:00:02Z (GMT). No. of bitstreams: 0 / Tese (Doutoramento) / IPEN/T / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP

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Submitted by Carlos Roberto Lopes Vicente null (crlvicente@hotmail.com) on 2018-03-06T19:32:11Z No. of bitstreams: 1 Dissertação Carlos.pdf: 1349576 bytes, checksum: 4bf9e37bb7bc9015d50dd54931d60cdd (MD5) / Approved for entry into archive by Elza Mitiko Sato null (elzasato@ibilce.unesp.br) on 2018-03-07T18:09:57Z (GMT) No. of bitstreams: 1 vicente_crl_me_sjrp.pdf: 1349576 bytes, checksum: 4bf9e37bb7bc9015d50dd54931d60cdd (MD5) / Made available in DSpace on 2018-03-07T18:09:57Z (GMT). No. of bitstreams: 1 vicente_crl_me_sjrp.pdf: 1349576 bytes, checksum: 4bf9e37bb7bc9015d50dd54931d60cdd (MD5) Previous issue date: 2018-02-23 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / Na busca por novos sistemas de comunicações muitos trabalhos têm sido realizados com o objetivo de obter constelações de sinais e códigos geometricamente uniformes no espaço euclidiano. Neste contexto, nossa proposta é identificar uma estrutura algébrica e geométrica para reticulados algébricos provenientes do homomorfismo canônico que possuam densidade centro ótima. Nesse sentido, a presente dissertação tem como foco as extensões galoisianas de grau primo ímpar p e encontrar estruturas de Z-módulos via essas extensões que gerem reticulados algébricos com densidade de centro ótima. / In the search for new communication systems many works have been performed in order to get constellation geometrically uniform signs and codes in Euclidean space. In this context, our proposal is to identify an algebraic and geometric structure for algebraic lattices from the canonical homomorphism possessing great center density. In this sense, this project focuses on the galoisian extensions of p odd prime degree and find Z-module structures via these extensions that create algebraic lattices with great center density. / 2015/20595-4

Orientador: Antonio Aparecido de Andrade / Banca: André Luiz Flores / Banca: Trajano Pires da Nóbrega Neto / Resumo: O objetivo deste trabalho e mostrar duas maneiras de se calcular o discriminante de um corpo de números. Da primeira forma, utilizando a teoria algébrica dos números clássica vimos como calcular o discriminante dos corpos quadráticos e corpos ciclotômicos. Através desta teoria é possível calcular o discriminante somente desses corpos com um árduo trabalho. Da segunda maneira utilizando os caracteres de Dirichlet e seus condutores vimos o cálculo do discriminante para qualquer corpo abeliano de uma maneira não muito trabalhosa. Finalmente, utilizando esses resultados damos aplicações sobre reticulados algébricos. / Abstract: The aim of this work is to make a parallel between two forms of computing discriminants of fields of numbers. In the first form, by classic algebraic number theory we computed the discriminant of quadratics fields and ciclotomic fields. Through of this theory, is possible to computing the discriminant alone of this fields with a arduous work. In the second form using Dirichlet's character and their conductors we computed the discriminant of any abelian field of a form not very hard. Finally, using this results we give applications on algebraic lattices. / Mestre