1,720,969 research outputs found
Studio dei siti minerari della Val Ponton, Val Clavalité e di Fenis (Aosta)
No full textStudio dei siti minerari della Val Ponton e della Val Clavalité e la datazione delle scorie di Fenis. La relazione contiene: 1) informazioni storiche e geologiche relative ai siti minerari a magnetite della Val Ponton (Massiccio serpentinitico del Monte Avic); 2) conoscenze di base geologiche e storiche relative ai siti minerari della Valle Clavalité (es., Lovignanaz e Tramail la Rossa) ubicati all'interno della sequenza di calcescisti e metabasiti della Falda Piemontese; 3) conoscenze di base geologiche e storiche relative al sito di Fenis (Miseregne); 4) studio petrografico delle rocce mineralizzate reperite nei vari giacimenti; 5) studio petrografico delle scorie metallurgiche provenienti dal deposito di Misérègne (Fenis) e datazione delle scorie tramite la tecnica del radiocarbonio
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Get PDFWe 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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
U-Th-Pb dating of hydrothermal ore deposits from electron probe micro-analysis of uraninite: the cases of Cogne, Val Vedello and Novazza (Italian Alps)
Get PDFUraninite (UO2) is an uncommon accessory mineral in some magmatic, metamorphic and sedimentary rocks. Chemical analyses of uraninite performed by electron probe micro-analyzer (EPMA) can be profitably used for U-Th-Pb dating. We employed this technique to constrain the age of formation of two types of hydrothermal deposits from the Italian Alps, namely an ophiolite-hosted magnetite deposit (Cogne, western Alps) and two uranium deposits (Novazza and Val Vedello, Orobic Alps). In the first case, we aimed to establish whether the Cogne magnetite deposit, a relatively uncommon type of ophiolite-hosted deposit, was Alpine or pre-Alpine. In the second case, we used uraninite to date the hydrothermal events responsible for widespread siderite occurrences in the Southalpine domain. At Cogne uraninite occurs as rare inclusions in magnetite and forms anhedral to euhedral crystals, ranging in size from 1 to 40 μm. Textural evidence suggests that uraninite formed contemporaneously with magnetite, thus uraninite was used to date the magnetite mineralization. Based on all the radiometric age determinations (n = 53), we calculated a weighted average age of 152.8 ± 1.3 Ma (mean square weighted deviation, MSWD = 1.3), which is consistent with a pre-Alpine genesis of the ore, related to an oceanic seafloor hydrothermal system. At the two uranium deposits of Novazza and Val Vedello (Orobic Alps), abundant carbonate minerals (mainly siderite and Fe-rich dolomite) are associated with sulfides (dominant sphalerite, pyrite and galena) and uraninite, and form disseminations, veins and impregnations in the volcanoclastic facies of the Early Permian Collio Formation. At both sites, uraninite shows textural equilibrium with siderite and Fe-rich dolomite, but widespread alteration and recrystallization complicate the scenario. Therefore, we only analyzed apparently unaltered uraninite grains, which are a few-micron large at Novazza and submicron- to micron-sized at Val Vedello. Radiometric ages for the Novazza deposit range from ~ 290 to ~ 130 Ma (n = 20). The uraninite ages for the Val Vedello deposit (n = 62) are scattered between ~270 and ~ 50 Ma, but one large (20 μm) uraninite grain has a plateau age of 169 ± 3 Ma (MSWD = 1.4; n =13). By
averaging the oldest ages obtained for Novazza and Val Vedello, we obtained a best-estimate formation age for siderite-uraninite mineralization of 275 ± 13 Ma (MSWD = 3.2; n = 6). Younger ages are interpreted to reflect protracted interaction with hydrothermal fluids and/or deformation/recrystallization during Jurassic rifting and successive Alpine orogenesis. Our examples confirm that uraninite EPMA chemical U-Th-Pb dating can be a valuable tool in solving some geological issues, having also the advantage of being more affordable and rapid, compared to other analytical techniques. Moreover, the improvement of EPMA resolution (spot size << 1 μm) in modern instruments may enlarge the range of potentially analyzable samples
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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