1,720,956 research outputs found
Archaeometallurgical researches in the Othris mountains (Greece)
No full textDuring a survey in an area of the Othris Mountains between Lamia and Dhomokos (Greek mainland) some slag heaps and ancient mining sites were examined and relevant samples collected. In the mining areas the main ores are copper sulphides and carbonates. No underground mine exploration was undertaken, so it was not possible to ascertain if the traces of ancient mining have survived the recent ore mining activities. Slags were found with Hellenistic sherds on the surface of some of the mining areas and in some of the settlement sites.
We have analysed different typologies of silicate slags: heavy and glassy slags. Some samples of furnace fragments have also
been analysed as well as few metallic slags (heavy slags), interpreted as remains of the reduction of copper ores. Principal phases observed are orthopyroxene, minor amounts of olivine and metallic phases. Textural evidence and mineral composition account for a reconstruction of the Cu-reduction process, which can be considered as efficient and accurate. The furnace fragments testify of the strong interaction between the charge and the furnace itself. The firing structure is thus participating in the reduction process together with ore and fuel
Studio petro-archeometrico di scorie di riduzione del rame della regione di Othris (Grecia)
No full textIron Age silicatic slags from Val Malenco (Italy): the role of textural and compositional studies in archaeometry.
No full textA petrographic study of copper smelting slags from several localities of Val Malenco (Italy) provides a key for unravelling the technologies used in reduction of copper ores during the Iron Age.
Thick “tap type” slags with “rope surface” structures and thin, flat slags, were analysed. All slags are made of olivine (up to 60%), oxides, sulfides, minor interstitial Fe-rich pyroxenes (esseneite and augite) and glass. Olivine is zoned, with Mg-rich cores, Fe-rich inner rims and thin Ca-rich outer rims. Observed mesh textures and the compositions of olivine cores and relic minerals, such as Cr-rich spinel, suggest that the mineralised levels of the Malenco ophiolitic complex were the source of the exploited ore. Ca-rich olivine rims and Ca-rich interstitial phases suggest a Ca-rich material was supposedly added during smelting to lower the melting point of the ore. The material used for this task could have been marbles or calcschists of ophicarbonates outcropping nearby Lanzada. Based on petrological considerations, the smelting conditions were constrained to a furnace in which, for
temperatures around 1080-1200 °C, oxygen fugacity was 10-13-10-8 atm
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
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
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