Propriedades estruturais e optoeletrônicas dos compostos SrSnO3, SrxBa1-xSnO3 e BaSnO3

In this work we present a study for the structural, electronic and optical properties, at ambient conditions of SrSnO3, SrxBa1

Nucleação e excitação de paredes de Néel em filmes finos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior

Termoestatística quântica: uma abordagem via estatísticas não-gaussianas

Considering a quantum gas, the foundations of standard thermostatistics are investigated in the context of non-Gaussian statistical mechanics introduced by Tsallis and Kaniadakis. The new formalism is based on the following generalizations: i) Maxwell- Boltzmann-Gibbs entropy and ii) deduction of H-theorem. Based on this investigation, we calculate a new entropy using a generalization of combinatorial analysis based on two different methods of counting. The basic ingredients used in the H-theorem were: a generalized quantum entropy and a generalization of collisional term of Boltzmann equation. The power law distributions are parameterized by parameters q;, measuring the degree of non-Gaussianity of quantum gas. In the limit q

Conducão eletrônica e propriedades termodinâmicas da molécula de DNA

In this thesis, we study the thermo-electronic properties of the DNA molecule. For this purpose, we used three types of models with the DNA, all assuming a at geometry (2D), each built by a sequence of quasiperiodic (Fibonacci and / or Rudin-Shapiro) and a sequence of natural DNA, part of the human chromosome Ch22. The first two models have two types of components that are the nitrogenous bases (guanine G, cytosine C, adenine A and thymine T) and a cluster sugar-phosphate (SP), while the third has only the nitrogenous bases. In the first model we calculate the density of states using the formalism of Dyson and transmittance for the time independent Schr odinger equation . In the second model we used the renormalizationprocedure for the profile of the transmittance and consequently the I (current) versus V (voltage). In the third model we calculate the density of states formalism by Dean and used the results together with the Fermi-Dirac statistics for the chemical potential and the quantum specific heat. Finally, we compare the physical properties found for the quasi-periodic sequences and those that use a portion of the genomic DNA sequence (Ch22).

Processos aleatórios não-markovianos: perfis de memória

One of the mechanisms responsible for the anomalous diffusion is the existence of long-range temporal correlations, for example, Fractional Brownian Motion and walk models according to Elephant memory and Alzheimer profiles, whereas in the latter two cases the walker can always "remember" of his first steps. The question to be elucidated, and the was the main motivation of our work, is if memory of the historic initial is condition for observation anomalous diffusion (in this case, superdiffusion). We give a conclusive answer, by studying a non-Markovian model in which the walkers memory of the past, at time t, is given by a Gaussian centered at time t=2 and standard deviation t which grows linearly as the walker ages. For large widths of we find that the model behaves similarly to the Elephant model; In the opposite limit (! 0), although the walker forget the early days, we observed similar results to the Alzheimer walk model, in particular the presence of amnestically induced persistence, characterized by certain log-periodic oscillations. We conclude that the memory of earlier times is not a necessary condition for the generating of superdiffusion nor the amnestically induced persistence and can appear even in profiles of memory that forgets the initial steps, like the Gausssian memory profile investigated here.

Estudo da interação no setor escuro através do parâmetro de hubble

A possible approach to the cosmological coincidence problem is to allow dark matter and dark energy to interact with each other also nongravitationally. Two general classes of interaction were considered in this thesis, characterized by a constant interaction parameter ( or

Mito e memória na construção de uma identidade local

CAVIGNAC, J. A. Mito e memória na construção de uma identidade local. Organon, Rio Grande do Sul, v. 21, n.42, jan./jun. 2007. Disponível em: . Acesso em:

Helminths from Seven Species of Lizards (Reptilia: Squamata) at the Cerrado of Mato Grosso do Sul State, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

U-ages in soils and groundwater evidencing wet periods 400-600 kyr ago in southeast Brazil

U-238 and its radiogenic daughter U-234 have been utilized for dating soil formation and groundwater residence time during the last 1.5 million years, in this case based on the U-clissolution/precipitation occurring during modifications of the oxidation-reduction conditions. In this paper, we report a 400-600 kyr proxy of wet periods from sediments occurring in a soil profile developed over rocks outcropping at the Parana sedimentary basin in Brazil, and from groundwater exploited of Guarani aquifer at the same basin. The approaches indicated successful use of the U-modeled ages for suggesting wet periods exceeding the past 116-210 kyr from previous studies. (C) 2007 Elsevier Ltd. All rights reserved.

Natural radionuclides in major aquifer systems of the Parana sedimentary basin, Brazil

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

A comparative study of aquifer systems occurring at the Parana sedimentary basin, Brazil: major hydrochemical trends

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Radon and progeny (Pb-214 and Bi-214) in urban water-supply systems of São Paulo State, Brazil

Many water-supply systems in South America utilize the waters of the Guarani aquifer at least as part of their networks. However, there is little present knowledge in Brazil of the factors affecting Rn presence in the water supplied for end-users, despite the economic importance of Guarani aquifer. Rn-222 analyzes of 162 water samples were performed at 8 municipalities in São Paulo State, Brazil, with the aim of investigating the major factors affecting its presence in solution. The Rn-222 activity concentration ranged from 0.04 up to 204.9 Bq/L, with three samples exceeding the World Health Organization maximum limit of 100Bq/L. Aeration was confirmed as the most important factor for Rn release, as expected due to its gaseous nature. Accumulation in pipes and stratification in the water column were other significant factors explaining the data obtained in some circumstances. The Rn daughters Ph-214 and Bi-214 were also determined in a set of selected samples and their presence was directly related to the occurrence of Rn dissolved in water. (c) 2008 Elsevier Ltd. All rights reserved.

Habermas lendo Peirce

Entre as várias referências feitas ao pensamento de Peirce, ao longo de sua carreira filosófica, dois textos foram tomados como exemplares da leitura que Jürgen Habermas faz do pensamento de Peirce e, ao lado das diferenças encontradas entre os dois textos, dois itens muito importantes se conservam: a verdadeira admiração pela virada pragmática promovida por aquele filósofo e cientista, que será seguida por seu leitor, e a séria restrição feita à progressiva tendência do pensamento de abandonar a intersubjetividade como garantia da objetividade da semiose, dando preferência a uma fundamentação cosmológica para todo conhecimento. Embora esta última restrição pudesse ser criticada em sua pertinência, tanto a admiração manifesta à contribuição feita por Peirce ao pensamento filosófico com sua proposta pragmática, quanto a restrição a um suposto abandono das relações pessoais na base da semiose, sem dúvida, manifestam o viés filosófico de Habermas lendo um autor que ele admira, mas que não pretende seguir como um exegeta.

Dialelo entre linhagens de uma população de pepino do tipo 'Caipira'

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Saúde materno-infantil e nutrição de crianças Kaiowá e Guaraní, Área Indígena de Caarapó, Mato Grosso do Sul, Brasil

Este trabalho teve como proposta estudar o estado nutricional de crianças indígenas e conhecer condições de saúde materno-infantil. Trata-se de um estudo transversal, com uma amostra de 137 crianças de zero a 59 meses de idade, das comunidades Kaiowá e Guaraní, Área Indígena de Caarapó, Mato Grosso do Sul, Brasil. Foram realizadas entrevistas com a aplicação de um questionário sobre as condições de saúde materno-infantil. A avaliação nutricional foi obtida por meio de medidas antropométricas (peso e estatura). Verificou-se que 19,7% das mães não realizaram o pré-natal e 53,3% tiveram parto domiciliar. A ocorrência de desnutrição para o índice peso/idade foi de 18,2% e para o índice altura/idade foi de 34,1%. A proporção de crianças desnutridas quando separadas por sexo, faixa etária e escolaridade materna não apresentou diferença estatisticamente significante para ambos os índices. Este estudo evidenciou elevada ocorrência de desnutrição infantil e uma preocupante situação de saúde materno-infantil.