1,720,954 research outputs found
Decay and provenance of the volcanic rocks used to construct the pentagonal tower of the medieval castle of Serravalle (Bosa, W Sardinia, Italy)
No full textThe medieval castle of Serravalle, located at the top of the hill of the same name (81 m. above sea level), near the mouth of the Temo River, is one of the best-known medieval fortifications in Sardinia. The construction of the oldest part of the castle (according to F. Fara), is attributed to the Marchesi Malaspina di Villafranca, on their arrival in Sardinia, and is dated to the beginning of the 12th century (1112-1121). Recent studies, however, tend to shift both the arrival of the Malaspinas and the birth of the castle to the following century. They founded the new town of Bosa, moving the original nucleus called Bosa vetus two kilometres downhill; thus the late medieval village of Sa Costa (which makes up the historical centre of present-day Bosa) began to develop; it still exerts considerable historical fascination. The Serravalle castle complex was built in various stages; the construction of the earliest fortificatisons was followed by the erectiojn of four corner towers about 10 m tall, linked by a thick wall. The raising of the pentagonal tower located in the western corner of the boundary wall goes back to about 1330. The tower, which probably consisted of two storeys with wooden beams, now missing, and one stone one with a longitudinal arch, was built using pyroclastic rocks belonging to the Oligo-Miocenic volcanic cycle occurring in Sardinia between 33 and 11 million years ago. The pyroclastic rocks in the tower, with a composition varying from dacite to rhyolite (classification according to De La Roche, 1980), are extremely heterogeneous due to the different ways in which they were deposited and the varying occurrence of pumice, stone and phenocrystals. They display a porphyritic structure (with a porphyritic index of between 10 and 20) with phenocrystals of opaque (ilmenite, magnetite and/or titanomagnetite), plagioclase, ± biotite, and rare hornblend and quartz. Available data indicate that the pyroclastites utilised in the construction of the pentagonal tower have characteristics similar to the vulcanites outcropping in the surrounding area. On the basis of their physical properties (porosity, apparent and actual density, imbibition and saturation coefficients, etc.) and petro-volcanological characteristics, it was possibile to subdivide the volcanic rocks of the tower into two main groups: a) lava-like ignimbrites, with a medium to high degree of welding, with average values of open porosity and apparent density of 22.5±5.9% and 1.99±0.15 g/cm3, respectively; b) pyroclastites in prevalently cineritic facies, with a generally low degree of welding, with average values of open porosity and apparent density of 36.3±2.6% and 1.50±0.07 g/cm3, respectively. Degradation processes are distributed differently on the façades of the tower; they are mainly concentrated on those exposed to winds coming from the sea (north-west and west), and above all on weakly-welded pyroclastites. In the latter, the presence of cripto- and fano-efflorescence is highlighted, as well as the presence of various macroscopic forms of alteration: pitting, exfoliation, flaking, alveolation, differential degradation. In welded pyroclastites, processes of chromatic alteration and superficial exfoliation are prevalently present
Provenance and decay of the volcanic rocks used in the roman theatre of Nora (SW Sardinia, Italy). Further data and new considerations
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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
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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