1,721,016 research outputs found
Preliminary evaluation of the fatigue behaviour of aluminium alloy in corrosive environment
No full textFatigue behaviour of aluminium alloy in corrosive environment
No full textIn this work the effect of fatigue life reduction of 2024 Al alloy for aerospace components due to
the corrosive (exfoliation) environment is investigated. Both standard fatigue tests on prior corroded
samples and fatigue tests conducted with the samples in corrosive solution are developed in order
to define some guidelines for the inclusion of such effect in design and to improve aircraft life
management. The effect of corrosion is taken into consideration introducing specific concentration
factors into the life estimation relationship. Differences between fatigue in corroded specimens and
fatigue in presence of corrosive environment are emphasized. No crack propagation is considered.
Two alternative procedures are considered in the analysis: “a-procedure” based on maximum stress
calculated on un-corroded sample section; “b-procedure” based on stress calculated on final
residual section, including corrosion. Related concentration factors are derived and compared by the
experimental results with the aid of an original proposed ”power law” showing a substantial
equivalence of the considered procedures both in the case of prior corroded samples and in
combined situation. This tendency is consistent with the available data results. The combined effect
of fatigue load acting in presence of corrosive environment reveals an important reduction in fatigue
life that cannot be determined by means of classical fatigue tests performed on prior corroded
samples. Original analytical relations are introduced in order to manage such kind of combined
effect revealing consistency of data also if few samples were tested. An extensive experimental
investigation is deemed necessary to confirm the presented analytical approach and to improve the
capability to predict such phenomenon
Progetto S55 Replica
No full textIl Savoia Marchetti S55 è un idrovolante simbolo dei notevoli progressi tecnologici dell’Italia in campo aeronautico durante gli anni ’20 e ’30 e reso famoso da una serie di voli a lunga percorrenza da record. Nonostante la produzione toccò i 250 esemplari ad oggi non esiste nessun esemplare volante e solo uno di essi si è conservato fino ai giorni nostri ed è attualmente esposto nel museo aeronautico TAM in Brasile. Nel 2015 un gruppo di professionisti e appassionati del settore aeronautico ha avviato il progetto Replica55 coordinato dal comandante Francesco Rizzi, con l'obiettivo di progettare, costruire e far volare una replica del velivolo S55 (www.replica55.it). The Savoia Marchetti S55 is a seaplane symbol of the remarkable aeronautical know how reached in Italy in during the '20s and' 30s, and confirmed by a series of record long-range flights. Although were made about 250 aircraft, to date does not exists one flying airplane. Currently the only one remaining and preserved is exhibited in the TAM aeronautical museum in Brazil. In 2015 a group of competent and enthusiastic professionals of the aeronautics sector started the "Replica55 project" coordinated by the commander Francesco Rizzi, with the aim of designing, building and flying a replica of the S55 aircraft. (www.replica55.it)
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
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe 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
A Student Team Based Teaching Approach: The Team S55 Experience
No full textIn this paper the experience of a group of young engineers and students in aerospace engineering at the
Politecnico di Torino has been presented. It has been shown how they forming a working group for the
reconstruction of a flying model of the S55 seaplane designed and produced in Italy, beginning in 1924. The
TeamS55, founded at the end of 2016,currently consists of about a hundred people who are able to cover all
the phases of the aerospace production flow, from the conceptual design to the ground and flying test activities.
The TeamS55 can be considered as a replica of a current aerospace company where all the roles and functions
are adequately represented
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