1,720,995 research outputs found
Iron-rich natural mineral water and Fe biodisponibility: critical analysis of effectiveness in therapy.
No full textABSTRACT - Iron-deficency anemia is usually trated with iron administration (p.o or i.v.) that
frequently cause gastointestinal side-effects. Iron-rich natural mineraI waters are used in traditional
Thermal Medicine to menage siderophenic anemia. Recent clinical trials attested biodisponibility of
iron-mineral waters using new and more accurated methodology of analisys
Aging Treatment Of Selective Laser Melted Alloy 625: Mechanical Strength And Corrosion Resistance
No full textAdditive manufacturing is nowadays increasingly adopted to produce a large variety of components, especially with complex geometries. A deep investigation and optimization of the mechanical and corrosion performance of the selective laser melted Alloy 625 is extremely useful to support designers in the transition from the conventional to the additive manufacturing technology. Even though the selective laser melting technique is still associated with too high production costs and low productivity to enable a broader expansion, it permits to obtain excellent mechanical and corrosion properties compared to those of the conventionally manufactured alloy. Despite the additively produced material shows outstanding performance already in the as-built condition, aging treatments permit further strength improvement enabling possibility of reducing thicknesses, mass, resources consumption and environmental emissions. However, the balance between the mechanical and corrosion properties is critical and it requires a careful tuning of the heat treatment parameters
High- and low-cycle fatigue behavior of additively manufactured Ti6Al4V and influence of surface finish
Full text linkTi6Al4V has emerged as one of the most promising materials for Additive Manufacturing (AM). In this work, three series of AM Ti6Al4V samples were employed to assess the material fatigue behavior and its dependency on surface finish. One series was left in as-built conditions, one was machined, and one was finely polished. No samples underwent heat treatment, and their dimensions were chosen to be representative of the characteristic strut size of AM reticular structures. The as-built and machined series were characterized in terms of roughness, monotonic, Low-Cycle Fatigue (LCF) and High-Cycle Fatigue (HCF) behaviors. The polished series was intended to determine the fatigue limit under ideal surface finish conditions, undergoing roughness and HCF tests only. This allowed the determination of the fatigue limit reduction factors due to surface finish, providing designers with a practical tool for evaluating the effect of surface roughness on the fatigue performance of AM Ti6Al4V. Besides, scanning electron microscopy and fracture mechanics analysis through Kitagawa-Takahashi diagrams, based on Murakami's theory, were performed. Different laws correlating defect size and fatigue limit of defective components were compared. By transforming roughness into an equivalent defect, further insight into the effect of surface finish on fatigue performance was gained
Deep cryogenic treatment of AA7050: tensile response and corrosion susceptibility
Full text linkCryogenic treatments represent an innovative technology developed with the aim of improving the performance of metallic alloys. The beneficial effects on steels are well documented in the literature, whereas their influence on other materials, such as aluminum alloys, is still not completely clarified. Even if the scientific literature reports conflicting data and conclusions, the industrial applications of such treatments are constantly growing. In the present experimental work, the mechanical and corrosion properties of a high-performance 7050 aluminum alloy plate were studied after cryogenic treatment at − 196 °C in liquid nitrogen. Tensile tests were performed on heat-treated samples, and intergranular corrosion tests were carried out on prismatic samples, according to ASTM G110-92 standard. The specimens were exposed to the corrosive environment and the effect of intergranular corrosion was measured by quantitative analysis using light-optical microscopy (LOM). Whereas trifling variation was observed in the mechanical resistance and plastic behavior, the corrosion tests showed a benefic effect of the cryogenic treatment. The microstructure was investigated by FEG-SEM analysis, revealing a different distribution of precipitates near the grain boundaries, which was able to reduce the electrochemical potential difference among these regions and the center-grain
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
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