A simple procedure for the preparation of laponite and thermoplastic starch nanocomposites: Structural, mechanical, and thermal characterizations

The aim of this article is to propose advances for the preparation of hybrid nanocomposites prepared by the combination of intercalation from solution and melt-processing methods. This research investigates the effect of the laponite RDS content on the thermal, structural, and mechanical properties of thermoplastic starch (TPS). X-ray diffraction was performed to investigate the dispersion of the laponite RDS layers into the TPS matrix. The results show good nanodispersion, intercalation, and exfoliation of the clay platelets, indicating that these composites are true nanocomposites. The presence of laponite RDS also improves the thermal stability and mechanical properties of the TPSmatrix due to its reinforcement effect which was optimized by the high degree of exfoliation of the clay. Thus, these results indicate that the exfoliated TPS-laponite nanocomposites have great potential for industrial applications and, more specifically, in the packaging field. © The Author(s) 2011 Reprints and permissions: sagepub.co.uk/journalsPermissions.nav.

Análise e implementação de um algoritmo de busca dispersa para o planejamento da expansão de sistemas de transmissão

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Análise de multirresolução baseada em polinômio potência de Sigmóide - Wavelet

Pós-graduação em Ciência da Computação - IBILCE

Desenvolvimento e caracterização de compósito processados por RTM para aplicação aeroespacial

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

Síntese e caracterização do titanato de cálcio dopado com escândio

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O Plano Nacional de Qualificação do Trabalhador: formulação, implementação e as práticas pedagógicas dos professores do CEFET/PA

Nesta pesquisa, elegemos como objeto de estudo o PLANFOR, a fim de identificarmos as intenções, o projeto e as diretrizes orientadoras para a formação profissional estabelecidas por esse Programa no CEFET/PA, analisando se ele contribuiu para a renovação no desenvolvimento das práticas pedagógicas dos professores da Educação Profissional no âmbito dessa instituição. Os procedimentos metodológicos adotados para a realização da pesquisa priorizaram os aspectos qualitativos da investigação, por meio de uma revisão da literatura sobre o tema, que incluía a pesquisa e os trabalhos mais significativos sobre o PLANFOR, tais como os de Almeida (2003), Azeredo (1998), Bulhões (2001), Frigotto (2002), Manfredi (2002); e sobre a ação docente: Candau (2005), Cunha (2004), Martins (2000) e Rays (1996) que se constituem em nossas principais referências de análise. A pesquisa bibliográfica foi realizada paralelamente à pesquisa documental, a fim de reunir informações acerca do processo de implementação do PLANFOR no CEFET/PA. Também utilizamos a observação empírica para o desenvolvimento deste estudo. A geração dos dados foi realizada por meio de entrevistas com roteiro semi-estruturado, aplicadas a seis professores de cursos técnicos, envolvidos no processo de implementação do plano. As falas dos entrevistados foram analisadas e, por sua vez, suscitou as conclusões : a) o CEFET/PA executava os Cursos indicados pela SETEPS, que definia toda a organização e desenvolvimento dos cursos o que impossibilitou a inovação por iniciativa própria do CEFET IP A; b) a falta de esclarecimentos sobre as intenções, metas e diretrizes do programa, informações sobre o públicoalvo não possibilitou um direcionamento para a renovação pedagógica, pois para os professores não ficou claro o que era o PLANFOR; c) em relação aos projetos dos cursos e as práticas pedagógicas, estes continham carga horária pequena, impedindo seu aprofundamento; a pouca quantidade de aulas teóricas; a pouca articulação entre a teoria e a prática; predominância do conservadorismo das metodologias de ensino reproduzindo práticas pedagógicas ultrapassadas; deficiente integração entre as habilidades básicas, especifica e de gestão enfatizando as habilidades específicas, no "saber fazer" e no conhecimento instrumental.

Division of labor between M and P visual pathways: different visual pathways minimize joint entropy differently

Visual perception and action are strongly linked with parallel processing channels connecting the retina, the lateral geniculate nucleus, and the input layers of the primary visual cortex. Achromatic vision is provided by at least two of such channels formed by the M and P neurons. These cell pathways are similarly organized in primates having different lifestyles, including species that are diurnal, nocturnal, and which exhibit a variety of color vision phenotypes. We describe the M and P cell properties by 3D Gábor functions and their 3D Fourier transform. The M and P cells occupy different loci in the Gábor information diagram or Fourier Space. This separation allows the M and P pathways to transmit visual signals with distinct 6D joint entropy for space, spatial frequency, time, and temporal frequency. By combining the M and P impacts on the cortical neurons beyond V1 input layers, the cortical pathways are able to process aspects of visual stimuli with a better precision than it would be possible using the M or P pathway alone. This performance fulfils the requirements of different behavioral tasks.

Modelagem do mCSEM no domínio do tempo usando transformada discreta de Fourier

A modelagem do mCSEM é feita normalmente no domínio da frequência, desde sua formulação teórica até a análise dos resultados, devido às simplificações nas equações de Maxwell, possibilitadas quando trabalhamos em um regime de baixa frequência. No entanto, a abordagem através do domínio do tempo pode em princípio fornecer informação equivalente sobre a geofísica da subsuperfície aos dados no domínio da frequência. Neste trabalho, modelamos o mCSEM no domínio da frequência em modelos unidimensionais, e usamos a transformada discreta de Fourier para obter os dados no domínio do tempo. Simulamos ambientes geológicos marinhos com e sem uma camada resistiva, que representa um reservatório de hidrocarbonetos. Verificamos que os dados no domínio do tempo apresentam diferenças quando calculados para os modelos com e sem hidrocarbonetos em praticamente todas as configurações de modelo. Calculamos os resultados considerando variações na profundidade do mar, na posição dos receptores e na resistividade da camada de hidrocarbonetos. Observamos a influência da airwave, presente mesmo em profundidades oceânicas com mais de 1000m, e apesar de não ser possível uma simples separação dessa influência nos dados, o domínio do tempo nos permitiu fazer uma análise de seus efeitos sobre o levantamento. Como parte da preparação para a modelagem em ambientes 2D e 3D, fazemos também um estudo sobre o ganho de desempenho pelo uso do paralelismo computacional em nossa tarefa.

Aspectos da cienciometria aplicados a um estudo de caso: área de Letras

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

Transformações de Lorentz e seus invariantes

In this paper, we will show the types of Lorentz transformations, from the most described in books, special Lorentz transformation that relates two inertial systems whose relative velocities are directed along an axis of the respective bases systems. However, we will see a peculiarity that goes unnoticed in this transformation, although they have reported in many books a parallel between the transformation inertial systems, due to the fact that the speed is parallel to an axis, it is actually a semi-parallel processing. The next transformation that we will see is one in which a system moves with a relative speed that has arbitrary direction with respect to a given system, we will show that this transformation may be appointed as non-rotational Lorentz transformation. Before obtain, the later type of transformation, the rotational Lorentz transformation, which is the interface between Special Relativity and General Relativity, we will describe the systems to be rotated, not just inertial systems, show what the characteristics are that define the non-rotational and rotational transformations. The in last topic of this chapter we will also show how the idea of Thoma’s theorythat uses this transformation to create what he defines as the proper coordinate axes of the particleused to obtain the factor 1/2 electron spin. In the last chapter we show how the Lorentz invariants are obtained, quantities measures that are also in different Lorentz reference, with the focus on mass that has erroneously been described in many books, that varies according to the agreement reference system

Concepções e corporeidades docentes na educação infantil

Pós-graduação em Educação Escolar - FCLAR

Contribuição da Teoria Ator-Rede (T A-R) para o estudo da construção do conhecimento geográfico: uma leitura da introdução da New Geography no Brasil através da Sociologia das Associações

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

Analysis of elastic functionally graded materials under large displacements via high-order tetrahedral elements

The purpose of this study is to present a position based tetrahedral finite element method of any order to accurately predict the mechanical behavior of solids constituted by functionally graded elastic materials and subjected to large displacements. The application of high-order elements makes it possible to overcome the volumetric and shear locking that appears in usual homogeneous isotropic situations or even in non-homogeneous cases developing small or large displacements. The use of parallel processing to improve the computational efficiency, allows employing high-order elements instead of low-order ones with reduced integration techniques or strain enhancements. The Green-Lagrange strain is adopted and the constitutive relation is the functionally graded Saint Venant-Kirchhoff law. The equilibrium is achieved by the minimum total potential energy principle. Examples of large displacement problems are presented and results confirm the locking free behavior of high-order elements for non-homogeneous materials. (C) 2011 Elsevier B.V. All rights reserved.

Groups of services delivered by Brazilian branchless banking and respective network integration models

Over the last decade, Brazil has pioneered an innovative model of branchless banking, known as correspondent banking, involving distribution partnership between banks, several kinds of retailers and a variety of other participants, which have allowed an unprecedented growth in bank outreach and became a reference worldwide. However, despite the extensive number of studies recently developed focusing on Brazilian branchless banking, there exists a clear research gap in the literature. It is still necessary to identify the different business configurations involving network integration through which the branchless banking channel can be structured, as well as the way they relate to the range of bank services delivered. Given this gap, our objective is to investigate the relationship between network integration models and services delivered through the branchless banking channel. Based on twenty interviews with managers involved with the correspondent banking business and data collected on almost 300 correspondent locations, our research is developed in two steps. First, we created a qualitative taxonomy through which we identified three classes of network integration models. Second, we performed a cluster analysis to explain the groups of financial services that fit each model. By contextualizing correspondents' network integration processes through the lens of transaction costs economics, our results suggest that the more suited to deliver social-oriented, "pro-poor'' services the channel is, the more it is controlled by banks. This research offers contributions to managers and policy makers interested in understanding better how different correspondent banking configurations are related with specific portfolios of services. Researchers interested in the subject of branchless banking can also benefit from the taxonomy presented and the transaction costs analysis of this kind of banking channel, which has been adopted in a number of developing countries all over the world now. (C) 2011 Elsevier B.V. All rights reserved.

Chaotic encryption method based on life-like cellular automata

A chaotic encryption algorithm is proposed based on the "Life-like" cellular automata (CA), which acts as a pseudo-random generator (PRNG). The paper main focus is to use chaos theory to cryptography. Thus, CA was explored to look for this "chaos" property. This way, the manuscript is more concerning on tests like: Lyapunov exponent, Entropy and Hamming distance to measure the chaos in CA, as well as statistic analysis like DIEHARD and ENT suites. Our results achieved higher randomness quality than others ciphers in literature. These results reinforce the supposition of a strong relationship between chaos and the randomness quality. Thus, the "chaos" property of CA is a good reason to be employed in cryptography, furthermore, for its simplicity, low cost of implementation and respectable encryption power. (C) 2012 Elsevier Ltd. All rights reserved.