1,721,225 research outputs found
Ceramic raw materials: how to recognize them and locate the supply basins—mineralogy, petrography
No full textThis tutorial paper is focused on the mineralogical-petrographic characterization of clayey raw materials with the purpose of sourcing supply basins and answering questions about the provenance of the corresponding archaeological ceramic artefacts. The first part gives general indications of how to profitably study archaeological ceramic thin sections through the polarizing microscope. Brief notes are provided on the theoretical basis of optical microscopy. A scheme is then provided for the petrographic description of ceramic samples, concerning the textural and compositional characteristics of aplastic inclusions and groundmass. Suggestions are also given for identifying any minero-petrographic marker and establishing minero-petrographic groups (MGP) aimed at archaeological ceramic provenance studies. After broadly describing the geological origin of the clay deposits, there is discussion of how to plan a field survey aimed at the location of clay sources and sampling. The importance of the ethnoarchaeometric approach in provenance studies is also underlined. The third part of the paper describes the preliminary treatments to which the clayey raw materials are subjected before reporting on a grain size analysis and how to proceed when performing experimental firing tests. Finally some suggestions are made about how to compare clay firing tests (experimental briquettes) and archaeological ceramic finds when assessing a production centre
Measuring the quality of performance in CNR public research institutes: a comparison of methods
No full text
Appendice. Caratterizzazione petrografica e chimica dei reperti ceramici
No full textQuesta monografia costituisce la sintesi dello studio effettuato dall'autrice sulle ceramiche di produzione locale e di importazione rinvenute durante le campagne di scavo realizzate negli anni 2010-2014 lungo la cinta muraria di Erice. Sono stati analizzati in modo approfondito, fornendone un catalogo dettagliato, i frammenti ceramici provenienti dagli strati di fondazione delle mura di età arcaica, studiati nell'ambito del loro contesto di scavo
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
Archaeometric characterization of late Archaic ceramic from Erice (Sicily) aimed to provenance determination
Full text linkA set of 20 ceramic samples was autoptically selected from the numerous findings recovered from the stratigraphic excavations of the late Archaic city walls of Erice (western Sicily), in order to be analyzed with archaeometric techniques for provenance determination. The excavations were recently carried out as part of a research project funded by the Freie Universiat Berlin and the Fritz Thyssen Foundation. Specifically, the ceramic material consists of tableware with a painted geometric decoration of presumed local/regional production, as well as apparently imported black-glazed pottery. Both the categories can be traced back to a chronological period between the second half/last quarter of the 6th and the beginning of the 5th century BC. The methodological approach was aimed to the characterization of the ceramic pastes in terms of relative abundance, size distribution and mineralogical composition of the aplastic inclusions by the observation of thin sections with the polarizing microscope. The objective of the microscopic observations consisted in verifying the existence of textural and/or mineralogical analogies to be ascribed to the same clayey raw material and, consequently, to the same production centre. The chemical analyses of the same set of ceramic samples were carried out using the ICP-OES and ICP-MS techniques (55 elements in total). The aim of chemical analyses was to verify the adequacy of the petrographic classification and identify any chemical marker useful for provenance determination. All the analyzed samples of painted ceramic with geometric decoration have consistent compositional and textural characteristics, to the point of considering their assignment to a single 'paste group'. Specifically, it was found the use of very peculiar clay rich in calcareous bioclasts among the included aplastic and relatively poor in quartz and mica. The production, well distinguishable from those to date already attested in western Sicily, could be local. Concerning samples taken from the ceramic fragments decorated with black glaze, the evidence derived from mineralogical-petrographic observations and chemical analyses help confirm their importation from extra-insular production centres, specifically from the Attic region. The Ca-poor paste and the peculiar concentration of many trace elements such as Cr, Ni, Co, As, Pb, Zn, Cu, Sc, Be, V, Ga, Ge, Sn, Tl in the ceramic body strongly support this hypothesis
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