1,720,992 research outputs found
Kf evaluation in GFRP composites by thermography
Full text linkSince the presence of a notch in a mechanical component causes a reduction in the fatigue strength, it is important to know the kf value for a given notch geometry and material. This parameter is fundamental in the fatigue design of aeronautical components that are mainly made of composites. kf is available in the literature for numerous types of notch but only for traditional materials such as metals. This paper presents a new practice, based on thermographic data, for the determination of the fatigue notch coefficient kf in composite notched specimens. The innovative aspect of this study is therefore to propose the application on composite materials of a new thermographic procedure to determine kf for several notch geometries: circular, U and V soft and severe notches. It was calculated, for each type of notch, as the ratio between the fatigue limits obtained on the cold and hot zone corresponding to the smooth and notched specimen, respectively. Consequently, this research activity provides, for the first time, a little database of kf for two particular typologies of composite materials showing a fast way to collect further values for different laminates and notch geometries
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
Prevention of sudden cardiac death: focus on the subcutaneous implantable cardioverter-defibrillator
No full textThe implantable cardioverter-defibrillator (ICD) is the most effective therapy to prevent sudden cardiac death (SCD) in high-risk patients. To overcome infections and failure of transvenous leads, the most frightening complications of conventional ICDs, a completely subcutaneous ICD (S-ICD) has been developed and is currently adopted in routine clinical practice. In view of their long life-expectancy, low competitive risk of dying from non-arrhythmic causes, and high lifetime risk of lead-related complications requiring surgical revisions, young patients with cardiomyopathies and inherited arrhythmia syndromes have traditionally been considered ideal candidates for the S-ICD. However, as growing evidence supported S-ICD safety and efficacy, initial niche implant indications were abandoned in favor of a widespread use of this technology, that is currently adopted in common ICD candidates with severe left ventricular dysfunction. Indeed, guidelines recommend S-ICD implantation as an alternative to TV-ICDs in all ICD candidates, unless pacing is required. This review focuses on the contemporary experience with the S-ICD and explores future scenarios in which device-to-device communication will enable to combine leadless therapies
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