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Use of TEOS for fired-clay bricks consolidation
No full textEthyl silicate (tetraethylorthosilicate,
TEOS) is one of the most used consolidants for
natural stones in the restoration of architectural and
cultural heritage and the literature concerning its
performance in this application is quite abundant. In
this paper, the need, and sometimes urgency, of
preserving ancient fired-clay elements (bricks and
terracotta decorations) is highlighted as well, and the
effects of ethyl silicate consolidation (75 wt% TEOS
in white spirit) are investigated from a microstructural,
physical–mechanical and aesthetic point of view.
Fired-clay brick samples (open porosity 45 %;
compressive strength 14 N/mm2) were treated and
then characterized by mercury intrusion porosimetry,
scanning electron microscopy, water absorption, compressive
strength test and spectrophotometry, to assess
the effects of the treatment. The TEOS treatment gave
encouraging results: a good penetration depth (about
10 mm), a limited reduction in porosity, a large
decrease in water absorption, a significant improvement
in compressive strength and a positive aesthetic
outcome. The results obtained pointed out TEOS
treatment as a promising solution for fired-clay bricks
consolidation
Ethyl silicate for surface treatment of concrete – Part II: Characteristics and performance
No full textIn this study, several aspects of the surface treatment of concrete with ethyl silicate were investigated. After the treatment, two different types of concrete (w/c 0.45 and 0.65) showed a dramatic decrease in
capillary suction, chloride diffusion coefficient and carbonation depth. A penetration depth into the concrete of about 3–5 mmwas assessed. Microstructural investigations showed evidence of a chemical interaction
of the amorphous silica gel within the concrete forming calcium silica gel and a selective distribution of silica gel, which was mainly deposited in the small pores. In addition, the brightness and colour changes of the concrete surfaces after the treatment were analyzed quantitatively, finding limited differences, further decreasing over time. This last aspect is relevant for architectural applications of concrete, for example façades of residential buildings, where the architects may be interested in using the texture of concrete but are concerned by possible colour changes related to surface treatments application
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
Multi-scale modelling of autogenous strains of an internally cured cementitious material
No full textVariations 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
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