Representation of transmission lines in modal domain using analytical transformation matrices

The phases of a transmission line are tightly coupled due to mutual impedances and admittances of the line. One way to accomplish the calculations of currents and voltages in multi-phase lines consists in representing them in modal domain, where its n coupled phases are represented by their n propagation modes. The separation line in their modes of propagation is through the use of a modal transformation matrix whose columns are eigenvectors associated with the parameters of the line. Usually, this matrix is achieved through numerical methods which does not allow the achievement of an analytical model for line developed directly in the phases domain. This work will show the modal transformation matrix of a hypothetical two-phase obtained with numerical and analytical procedures. It will be shown currents and voltage s at terminals of the line taking into account the use of modal transformation matrices obtained by using numerical and analytical procedures. © 2011 IEEE.

Chile: academic performance and educational management under a rigid employment regime

Includes bibliography

Equivalent representation of mutual coupling in transmission lines by discrete element

This paper describes a computational model based on lumped elements for the mutual coupling between phases in transmission lines without the explicit use of modal transformation matrices. The self and mutual parameters and the coupling between phases are modeled using modal transformation techniques. The modal representation is developed from the intrinsic consideration of the modal transformation matrix and the resulting system of time-domain differential equations is described as state equations. Thus, a detailed profile ofthe currents and the voltages through the line can be easily calculated using numerical or analytical integration methods. However, the original contribution of the article is the proposal of a time-domain model without the successive phase/mode transformations and a practical implementation based on conventional electrical circuits, without the use of electromagnetic theory to model the coupling between phases. © 2003-2012 IEEE.

A gender parity horizon in Latin America: the political representation of women

Includes bibliography

RBPI21 interacts with negative membranes endothermically promoting the formation of rigid multilamellar structures

rBPI21 belongs to the antimicrobial peptide and protein (AMP) family. It has high affinity for lipopolysaccharide (LPS), acting mainly against Gram-negative bacteria. This work intends to elucidate the mechanism of action of rBPI21 at the membrane level. Using isothermal titration calorimetry, we observed that rBPI21 interaction occurs only with negatively charged membranes (mimicking bacterial membranes) and is entropically driven. Differential scanning calorimetry shows that membrane interaction with rBPI21 is followed by an increase of rigidity on negatively charged membrane, which is corroborated by small angle X-ray scattering (SAXS). Additionally, SAXS data reveal that rBPI21 promotes the multilamellarization of negatively charged membranes. The results support the proposed model for rBPI21 action: first it may interact with LPS at the bacterial surface. This entropic interaction could cause the release of ions that maintain the packed structure of LPS, ensuring peptide penetration. Then, rBPI21 may interact with the negatively charged leaflets of the outer and inner membranes, promoting the interaction between the two bacterial membranes, ultimately leading to cell death. © 2013 Elsevier B.V.

Cortical representation of the horizon in V1 and peripheral scaling in mammals with lateral eyes

In the present investigation we mapped the primary visual area of the South American diurnal rodent, Dasyprocta aguti, by standardized electrophysiological mapping techniques. In particular, we performed a series of mapping experiments of the visual streak in the primary visual cortex. We found that the representation of the visual streak in V1 is greatly expanded, the nasal 10 degrees of the visual streak representation occupies ten times more cortical area than equivalent areas in the central or temporal representation. Comparison of these data with those on the density of ganglion cells in the retina at corresponding locations in the visual field reveal a significant mismatch between these two variables. The nasal representation is greatly expanded along the horizontal meridian in V1 as compared to the central and temporal regions whereas the density of ganglion cells decreases with progression along the visual streak from central region towards the nasal or temporal visual field. A review of the available data reveals that all lateral-eyed mammals exhibit a similar mismatch between the retinal and cortical representation of the visual field, and this mismatches is greater in those species with well defined visual streaks such as rabbit and agouti.

Estrutura e dinâmica de famílias com um filho com necessidades educacionais especiais

No contexto brasileiro, a investigação acerca das necessidades educacionais especiais concentra-se no estudo das dificuldades e possibilidades de inclusão desses alunos em classes regulares de ensino, enfatizando os processos de ensino e aprendizagem. Poucos estudos, no Brasil, admitem a família como objeto de análise, embora não se questione a sua importância para o desenvolvimento infantil. Dessa forma, com base no modelo bioecológico e na teoria estrutural sistêmica, admitindo-se a família como um campo de desenvolvimento comum a todos os membros faz-se necessário conhecer o modo como ela se estrutura para atender as demandas decorrentes da necessidade especial de seu filho e os efeitos dessa dinâmica nos demais membros. A partir disso objetivou-se descrever, a estrutura e a dinâmica de famílias de crianças com necessidades educacionais especiais, além de: analisar as interações e relações estabelecidas dentro de cada subsistema (conjugal, fraternal, parental) e entre eles, assim como identificar a organização familiar, a partir dos mecanismos de coesão e hierarquia de acordo com o modelo estrutural sistêmico. Como estratégia de pesquisa utilizou-se o estudo de casos múltiplos, com duas famílias de crianças com necessidades educacionais especiais, sendo uma menina surda, de dez anos, e um menino, de doze anos, com dificuldades de aprendizagem. Os instrumentos e técnicas aplicados foram: Roteiro de Entrevista Semi-Estruturado, Inventário de Rotina (IR), Observação Sistemática, Diário de Campo, Family System Test (FAST) e Genograma. Os escores de proximidade obtidos no FAST foram coerentes com os resultados do IR, demonstrando maior coesão na díade mãe-filho que na díade pai-filho, nas duas famílias; quanto à flexibilidade das fronteiras, em geral, a percepção das famílias foi de fronteiras rígidas, nos sistemas, familiar, parental e fraternal, sendo que, a distribuição de hierarquia foi percebida pela díade parental, nas duas famílias, como sinal de prediletância, para o subsistema fraternal, e dominação, para o parental, o que interferiu nas estruturas relacionais desses subsistemas percebidas pelos membros. Na avaliação do subsistema fraternal, a ausência de poder, representada pelos pais e a representação dessa variável pelas crianças resultou em diferenças de percepção, no grupo. Portanto, esse estudo permitiu, por meio da identificação das relações e percepções dos membros das famílias, a compreensão de sua dinâmica e a influência desta, na trajetória desenvolvimental das crianças e do grupo, a partir, das demandas decorrentes do diagnóstico e das estratégias peculiares a cada família para enfrentar as necessidades especiais de suas crianças. Percebe-se que a família, sendo a principal parceira da escola na educação, precisa ser olhada como um sistema cujas estratégias relacionais são fundamentais para que a criança tenha suas habilidades estimuladas podendo, assim, superar suas dificuldades.

A desmaterialização do espaço: um estudo das interfaces entre a produção ficcional e as teorias da pós-modernidade

Pós-graduação em Estudos Literários - FCLAR

Kallen-Lehmann representation of noncommutative quantum electrodynamics

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

Application of the PTT Model to Axisymmetric Free Surface Flows

This work is concerned with numerical simulation of axisymmetric viscoelastic free surface flows using the Phan-Thien-Tanner (PTT) constitutive equation. A finite difference technique for solving the governing equations for unsteady incompressible flows written in Cylindrical coordinates on a staggered grid is described. The fluid is modelled by a Marker-and-Cell type method and an accurate representation of the fluid surface is employed. The full free surface stress conditions are applied. The numerical method is verified by comparing numerical predictions of fully developed flow in a pipe with the corresponding analytic solutions. To demonstrate that the numerical method can simulate axisymmetric free surface flows governed by the PTT model, numerical results of the flow evolution of a drop impacting on a rigid dry plate are presented. In these simulations, the rheological effects of the parameters epsilon and xi are investigated.

On the contact stiffness and nonlinear vibration of an elastic body with a rough surface in contact with a rigid flat surface

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

Challenges of Knowledge Representation in Contemporary Archival Science

Since its emergence as a discipline, in the nineteenth century (1889), the theory and practice of Archival Science have focused on the arrangement and description of archival materials as complementary and inseparable nuclear processes that aim to classify, to order, to describe and to give access to records. These processes have their specific goals sharing one in common: the representation of archival knowledge. In the late 1980 a paradigm shift was announced in Archival Science, especially after the appearance of the new forms of document production and information technologies. The discipline was then invited to rethink its theoretical and methodological bases founded in the nineteenth century so it could handle the contemporary archival knowledge production, organization and representation. In this sense, the present paper aims to discuss, under a theoretical perspective, the archival representation, more specifically the archival description facing these changes and proposals, in order to illustrate the challenges faced by Contemporary Archival Science in a new context of production, organization and representation of archival knowledge.

Women s Representation in Trimalchio s Feast and The Great Gatsby

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

On the equivalence between the wave-packet phase space representation (WPPSR) and the phase space generated by the squeezed states

We show that the parametrized Wave-Packet Phase Space representation, which has been studied earlier by one of the authors, is equivalent to a Squeezed States Phase Space Representation of quantum mechanics. © 1988.