1,720,969 research outputs found
WATER-REPELLENT POZZOLANA-LIME MORTARS FOR THE MAINTENANCE AND PROTECTION OF ARCHITECTURAL SURFACES
No full textIn this research water-repellent renders, prepared by mixing hydrophobic compounds with
pozzolana-lime mortars, were studied in order to evaluate their suitability for restoration
applications. Water repellent admixtures, such as powdered siloxane-based products and
metal soaps (zinc and calcium stearates), were mixed with a pozzolana-lime binder similar to
historical binders with hydraulic properties. The chemical-physical and structural properties,
the effectiveness and the durability of the water-repellent mortars in different environmental
conditions were studied. The influence of the water repellent admixtures on the chemical and
physical properties was evaluated by FT-IR analyses, by testing the mechanical properties
and the behaviour in presence of water. The durability of the water-repellent mortars was
evaluated after the exposure to artificial weathering (UV-light and water) and to
immersion/drying cycles in saturated sodium sulphate solution. The nature of the waterrepellent admixtures influenced both the hydration reactions and the chemical-physical
properties of the mortars resulting in different resistance to the weathering and to salt
crystallization
A comparative analysis of masonry chimneys: typical damages and preservation strategies
No full textDuring the industrial revolution, the diffusion of furnaces for different productive activities implied a spread use of masonry chimneys for disposal of the emitted combustion smoke. Their presence became a symbol of the manufactory growth in Western countries and contributed to characterize the skyline of areas, as the churches bell towers in the past. A large number of these structures are now listed as protected buildings by the Italian Ministry of Cultural Heritage, and this implies that they have to be repaired and maintained in a good and safe state of conservation, also when the factories in which are inserted are completely disused or demolished. In the paper, a series of recurrent damages observed on different disused Italian chimneys is reported, particularly in Lombardy region. Some general remarks will be given, based on the experience made on some masonry chimney in Northern Italy, with the aim to define a correct preliminary approach to the structural analysis and to their conservation
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
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