Browsing by Issue Date, starting with "1995"
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- La dimension personelle dans la formation des enseignants de l'enseignement de base du 1er cycle à MadèrePublication . Sousa, Jesus Maria Angélica Fernandes
- Os Exercícios preparatórios de Élio Téon de AlexandriaPublication . Duarte, Rui Miguel de Oliveira; Júnior, Manuel Alexandre
- A doutrina da guerra nas crónicas portuguesas dos séculos XIV e XVPublication . Antunes, Luísa Maria Soeiro Marinho
- Squiggle e o imaginário infantíl: contribuições ao estudo da relação entre o desenvolvimento emocional da criança e a sua expressão pela técnica do SquigglePublication . Franco, Maria da Glória Salazar d’ Eça Costa
- The Feynman integrand for the perturbed harmonic oscillator as a Hida distributionPublication . Cunha, Mário; Drumond, Custódia; Leukert, Peter; Silva, José Luís; Westerkamp, WernerWe rwiew some basic notions and results of White Noise Analysis that are used in the con struction of the Feynman integrand as a generalized White Noise functional. We show that the Feyn man integrand for the harmonic oscillator in an external potential is a Hida distri
- Dealing with the useful window related with the far field patternPublication . Casimiro, António Manuel E. S.; Azevedo, Joaquim A. R.; Grilo, Alberto J. V. V.With a convenient representation, the radiation pattern of a spatial distribution of radiating sources is always related with that distribution by a window in the inverse Spatial Fourier Transform of the distribution. This fact is used to change the distribution of sources without disturbing the radiation pattern. On the other hand, the error, in the mean square sense, made by source elimination is also related with the Fourier Transform of the distribution. So it spreads all over the domain and not only inside the useful window. This must be taken in account and, with some signal processing, it is possible to find the error only in the far field pattern using the spatial distributions of sources.
- A discrete model for the design sensitivity analysis of multi-layered composite shells of revolutionPublication . Soares, Cristovão M. Mota; Cordeiro, N. M. Marques; Barbosa, J. InfanteThis paper studies the sensitivity analysis for the optimization of the multi-layered composite axisymmetric shells subjected to arbitrary static loading and free vibrations. The structural analysis is carried out using a two node frustum-cone finite element with 16 degrees of freedom based on Love-Kirchhoff assumptions. The design variables are the angle of orientation of the fibers and/or the vectorial distances from middle surface to upper surface of each ply. The constraint functions are displacements, stresses (Tsai-Hill criterion) and the natural frequency of a specified mode shape. Four types of objective functions can be used: maximum displacement or natural frequency or elastic strain energy and material volume. The design sensitivities are calculated analytically, semi-analytically and by global finite difference. The potentiality of the proposed model and the accuracy of the sensitivities of response are discussed with reference to the applications.
- Esforço, custos e benefícios da reprodução em iguanas marinhasPublication . Dellinger, Frank Thomas Ussener
- A Malato-desidrogenose das plantas superiores - a estrutura, propriedades, regulação e funçõesPublication . Carvalho, Miguel Ângelo Almeida Pinheiro de; Zmlynakhim, Alexander Alexei
- Characterization of the cork surface by inverse gas chromatographyPublication . Cordeiro, Nereida; Neto, Carlos Pascoal; Gandini, Alessandro; Belgacem, Mohamed NaceurInverse gas chromatography (IGC) at infinite dilution has been used to study the surface properties of cork from Quercus suber. The dispersive component of its surface energy was determined at different temperatures using n -alkanes as probes, and a γDS value of 38 ± 1 mJ · m-2 at 40°C was obtained. The surface acid (A)/base (B) properties were also evaluated by using polar probes and the results indicate that cork has an amphoteric character, with a KA /KB = 1.1. The advantages of IGC, compared with the technique of contact angle measurements in the characterization of the cork surface, are discussed.