1,721,159 research outputs found
Le modelé quaternaire de la plaine d'Appiano-Caldaro près de Bolzano : G. B. Castiglioni et L. Trevisan, La Sella di Appiano-Caldaro presso Bolzano nel Quaternario
No full textGabert Pierre. Le modelé quaternaire de la plaine d'Appiano-Caldaro près de Bolzano : G. B. Castiglioni et L. Trevisan, La Sella di Appiano-Caldaro presso Bolzano nel Quaternario. In: Annales de Géographie, t. 84, n°464, 1975. p. 482
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
Optimizing a Step Casting Geometry to Evaluate the Mechanical Properties of AM60B Magnesium Alloys
No full textThe purpose of the research was the optimization of an existing permanent mould in order to achieve sound and reliable Mg alloy castings. To understand how the existing runner system affected the filling behaviour, specific process parameters were investigated. In particular both the material and the die temperatures, and the filling parameters, were analysed using MAGMASOFT® software. Firstly, the computational approach allowed to understand that the whole casting process had to be within 4÷5 seconds in order to not produce freezing phenomena, but anyway turbulence was still present. It was clearly evident that the main problem was in the die geometry, so the decision to design a new one. The ingates were redesigned, as well as the “non-returning” trap. A better control of the molten metal ingate speed was also obtained by adding a filter. By this configuration an adequate flow rate was achieved to not produce freezing phenomena and a significant reduction of turbulences. The present work shows a comparison of the simulation results to evidence how an optimized design of the runner system can significantly reduce the presence of casting defects, allowing to identify the real mechanical properties of AM60B Mg alloys
Optimization of a step casting die geometry to evaluate the potential mechanical performance of AM60B magnesium alloys
No full textNon-destructive testing has been carried out on AM60B magnesium alloy castings obtained by using two different permanent moulds. The results highlighted a very different defects content. In this paper, the benefits of adopting an optimised die to better evaluate the final castings’ properties are analysed. Numerical simulations have been performed to study the filling and the solidification behaviour of the alloy by changing the die cavity geometry, in order to minimise the presence of defects. The redesigned runner system prevented inclusions to enter the die cavity and allowed a laminar flow of the metal through the gate. Further, defects formation has been investigated using criteria functions provided by the simulation software, and the results confirmed the reliability of the die design. Comparing the simulation and experimental results, it's possible to verify a good correspondence, so allowing to establish semi-empirical rules to forecast the final properties of Mg alloys castings
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
Secretory structures and essential oil composition in Stachys officinalis (L.) Trevisan subsp. officinalis (Lamiaceae) from Italy
Full text linkThe secretory structures and the volatile fraction of Stachys officinalis (L.) Trevisan subsp. officinalis (Lamiaceae) from Italy were studied for the first time. Peltate and small capitate trichomes were observed on the whole plant (leaves and inflorescences). In the peltate trichomes, an unusual polyphenols content was evidenced by the histochemical methods. The volatile fraction was obtained by a solvent extract from the distillation water of leaves and inflorescences and analysed by GC-MS. Forty-four constituents for leaves, representing 94.1% of the total volatiles, and 57 compounds for flowers, accounting for 90.1% of the total volatiles, were identified. (E)-caryophyllene (20.1%), (E)-nerolidol (14.3%), caryophyllene oxide (6.1%) and γ-cadinene (5.7%) were recognised as the main constituents for the leaf volatile fraction, while caryophyllene oxide (16.5%), (E)-nerolidol (15.4%), humulene epoxide II (9.2%) and α-pinene (7.0%) were the main compounds for the flower volatile fraction
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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