1,721,055 research outputs found
Composites Interlaminar Toughening Techniques by Means of Interleaved Nanofiber Veils: Experimental Evaluation
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Design and manufacturing of skins based on composite corrugated laminates for morphing aerodynamic surfaces
Full text linkThe paper discusses the approaches for the design and manufacturing of morphing skins based on rectangular-shaped composite corrugated laminates and proposes a novel solution to prevent detrimental effects of corrugation on aerodynamic performances. Additionally, more complex corrugated shapes are presented and analysed. The manufacturing issues related to the production of corrugated laminates are discussed and tests are performed to compare different solutions and to assess the validity of analytical and numerical predictions. The solution presented to develop an aerodynamically efficient skin consists in the integration of an elastomeric cover in the corrugated laminate. The related manufacturing process is presented and assessed, and a fully nonlinear numerical model is developed and characterized to study the behaviour of this skin concept in different load conditions. Finally, configurations based on combinations of individual rectangular-shaped corrugated panels are considered. Their structural properties are numerically investigated by varying geometrical parameters. Performance indices are defined to compare structural stiffness contributions in non-morphing directions with the ones of conventional panels of the same weight. Numerical studies also show that the extension of the concept to complex corrugated shapes may improve both the design flexibility and some specific performances with respect to rectangular shaped corrugations. The overall results validate the design approaches and manufacturing processes to produce corrugated laminates and indicate that the solution for the integration of an elastomeric cover is a feasible and promising method to enhance the aerodynamic efficiency of corrugated skins
Recanalization of a Challenging Chronic Total Occlusion of the Superficial Femoral Artery through the Profunda Femoris Using a Pure Retrograde Technique
No full textInterosseous artery collaterals and their support to ulno-palmar arch: A case report and a review of the literature
No full textModelling and Monitoring the Response of Bonded Composite/Metallic Structures During Manufacturing Process and Damage Evolution
Full text linkThe paper proposes experimental and numerical approaches to investigate and characterize delamination phenomena at the interfaces between carbon fibre reinforced composite laminates and layers of titanium alloy, obtained through co-cured and co-bonding process. The build-up of thermal residual stress between the different materials is controlled by properly designing specimens suited to be adopted in fracture mechanics experiments, such as Double Cantilever Beam (DCB) or End Notched Fracture tests (ENF). Manufacturing process is monitored through the insertion of strain sensors carried by optical fibres, which are subsequently used to monitor the strain evolution during DCB tests, performed with two different types of specimens. Numerical models are developed for the estimation of thermal stress during the cooling phase of manufacturing process and of the mechanical response in fracture tests. The results confirm that the proposed specimens can control the development of distortions due to the mismatch of coefficients of thermal expansion and point out capabilities and limits of simplified linear numerical approaches to capture the development of strains and stress during the cooling phase of manufacturing process. The optical fibre based monitoring system successfully monitored both the manufacturing process and the evolution of internal strains during the development of interface damage. A complete numerical approach is developed, by using multistep explicit analyses to carry out simulation of fracture propagation after an evaluation of thermal stress in the structure. The approach is validated in terms of overall force vs. displacement responses and local strain evolutions at the locations monitored by internal strain sensors
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
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