1,720,998 research outputs found
Portable EDXRF investigation of the patinas on the Riace Bronzes
No full textThis paper summarizes the experimental results concerning the Energy Dispersive X-ray Fluorescence (EDXRF) analysis of patinas on two Riace Bronzes, kept in the National Archaeological Museum of Reggio Calabria (Calabria, Southern Italy). The two large Greek sculptures, famous nude bearded warriors both dated in the fifth century BC, are without a doubt, two masterpieces of inestimable historic and artistic value. EDXRF survey had the aim to determinate the chemical composition of the surface of these two bronze statues and to discriminate their different patinas. In particular, the concentration of sulphur, chlorine, tin, manganese, iron, copper, zinc and lead was determined by using a portable apparatus. Multivariate statistical analysis was carried out in order to identify possible correlations and/or differences of elemental composition among the patinas of these two statues. The information obtained made it possible to improve knowledge about the patinas of the Riace Bronzes, and this may help further studies and subsequent methods of restoration and/or of preservation of the two celebrated Greek sculptures
X-ray fluorescence for the study of the patinas on an outdoor bronze monument
No full textThe aim of this paper is the analysis of main elements of the patinas on an outdoor bronze monument, through the use of a portable Energy Dispersive X-Ray Fluorescence (EDXRF) equipment. In particular we investigated the concentration of copper, tin, lead, calcium, iron, sulphur and chlorine on the patinas of a bronze statue dedicated to Sigismondo Castromediano, which was created in 1905 and later placed in Lecce (Apulia, Southern Italy). Thanks to the versatility of the EDXRF portable apparatus we carried out a complete scan of the monument in a relatively short time. This has enabled us to obtain useful information on the patinas in a completely non-invasive way. EDXRF experimental data demonstrated that the two analysed parts of the monument are constituted by different bronzes, whereas the elements that characterize the depositions are equivalent in the two monitored parts. Moreover, multivariate statistical analysis was carried out in order to identify possible correlations and/or differences of elemental composition among the patinas of these two statues. Finally, a X-Ray Diffraction (XRD) analysis was carried out on a sample of deposit collected from an area of the statue not exposed to the washing away, in order to identify the phases of the deposit and to evaluate possible corrosion products. The main results of XRD analysis show that there are not corrosion products and the deposit is due to suspended particulate. The information obtained can be helpful for both archaeological and conservation studies for possible future monitoring and/or restoration work of the statue in object
Non-invasive in-situ analysis of a wreath of gold leaves from the National Archaeological Museum of Taranto, Italy
No full textThe purpose of this work is to undertake a detailed scientific investigation both on the alloy chemical composition and on the thickness of the gold foils of one of the most interesting wreaths from the National Archaeological Museum of Taranto (MArTA), Italy. This precious golden crown, which presumably dates back to the Hellenistic period, consists of eighteen gold leaves, whose chemical composition and thickness were determined in situ, and non-destructively, by using an energy dispersive X-ray fluorescence (EDXRF) portable instrument. Then, attenuation measurements of 59.6 keV γ-rays from a source of 241Am, were carried out to determine the thickness of the leaves. The results demonstrate that the analysed leaves have different chemical composition and various thickness
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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