1,721,123 research outputs found
Hygro-thermal bending behavior of porous FG nano-beams via local/nonlocal strain and stress gradient theories of elasticity
Full text linkThis work studies the bending response of porous functionally graded Bernoulli-Euler nano-beams under hygro-thermo-mechanical loadings. The governing equations of the elastostatic problems associated with both local/nonlocal stress- and strain-driven gradient models of elasticity were derived by using the virtual work principle. A Wolfram language code in Mathematica was then written to carry out a numerical investigation for different boundary conditions including cantilever and simply-simply conditions. The effects of the different parameters, such as porosity volume fraction, gradient index, nonlocal parameter, gradient length parameter and mixture parameter are presented. It is shown how the proposed approach is able to capture the structural behavior of porous functionally graded Bernoulli–Euler nano-beams under a hygro-thermal environment
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Solution for cross- and angle-ply laminated Kirchhoff nano plates in bending using strain gradient theory
No full textThe static analysis of Kirchhoff nano plates subjected to uniformly (UDL) and sinusoidally (SSL) distributed load is computed. The strain gradient nonlocal theory has been employed in order to involve the size effects of nanostructures in classical continuum theory. The governing equation of motion of Kirchhoff in weak form are applied to nano plates, involving second-order strain gradient nonlocal theory. Thus, the obtained partial differential equations have an increased order of derivation respect to the classical theory, from the fourth to the sixth. The displacements are carried out following the Navier procedure for simply supported boundary conditions. Isotropic and antisymmetric orthotropic laminates, both cross- and angle-ply are studied, for different layouts involving different material properties. Dimensionless outcomes in terms of transverse displacements, and normal and shear stresses, are given to changing aspect ratio and non local ratio, also making a comparison with the classical theory
Some Remarks on the Nonlinear Modelling of Parametric Rolling
No full textThe stability of upright ship position in longitudinal waves against the onset of parametric rolling has been investigated by a number of authors. The main aim was the analysis of threshold for parametric roll excitation in terms of wave height, ship stability and course. Some researchers investigated also the problem connected with the definition of the threshold in a stochastic environment, but the problem is still partly open. In this paper some shortcomings connected with the linear approach are highlighted, together with a preliminary analysis of the possibility of a nonlinear description based on concentrated parameters nonlinear description of the roll motion amplitude above threshold, a feature that can only be approached taking into account model nonlinearities
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