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Structural Bending Behaviour of an All-Composite Wing-Box with Delamination
No full textCarbon-fibre reinforced structures are more and more used in aerospace due to their excellent mechanical properties and their sig-nificant weight reduction. However, due to their complex damage mechanisms, composite structures can have significant local reduction in strength which can influence the global structural behaviour. Among the different failure mechanisms, the delamination between two adjacent fibre reinforced layers of a laminate, caused by a low velocity impact threat, can be very dangerous especially under compressive loading conditions. If a delami-nation exceeds a certain size, it will progres-sively grow under the service load conditions. The resulting loss in strength and stiffness may cause the premature failure of the dam-aged component.
In order to characterize the on-set and the growth of the impact induced delaminations in wing-box composite stiffened panels, an in-tegrated numerical tool has been developed within the ANSYS FEM code.
Starting from the impact energy and im-pact location, the delamination size and loca-tion along the panel thickness is found by means of the Davis & Zhang procedure [1]. Then, a geometrically non linear analysis is carried out on the panel with delamination so as to find its residual strength. The delamination growth is taken into account using an Energy Release Rate based approach. The delaminated area has been modeled using shell elements placed in the mid-planes of the sub-laminates and the Energy Release Rate has been calculated by means of the Virtual Crack Closure Technique [2] for shell elements which has been implemented in the ANSYS FEM code. Finally, a sensitivity analysis has been performed to evaluate the influence of the impact energy and the impact location on the residual strength of the wing-box composite stiffened panels under investigation
DRS UV-VIS AND EPR SPECTROSCOPY OF HYDROPEROXO AND SUPEROXO COMPLEXES IN TITANIUM SILICALITE
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Characterization and catalytic activity of CuCl2-Al2O3 ethylene oxychlorination catalysts
No full textGoing Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Structure and Reactivity of Framework and ExtraframeworkIron in Fe-Silicalite as Investigated by Spectroscopic and Physicochemical Methods
No full textThe application of IR, Raman, UV-visible, EPR, XANES, EXAFS, and TPR techniques to the determination of the Fe3+local environment in Fe-silicalite is described and discussed. These methods give information concerning the structural changes of the zeolitic structure, upon thermal treatments and interaction with adsorbates. In particular the effect of template burning at 773 K or at 973 K on the local Fe3+environment has been discussed in detail. The reactivity of the zeolite towards NH3has also been considered
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
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