1,720,963 research outputs found
Chemical characterization of wood samples colored with iron inks: insights into the ancient techniques of wood coloring
No full textIn the past, the practice of dyeing wood was very widespread, for instance for obtaining substitutes for rare and expensive ebony, which was used for all marquetry techniques and especially for making inlays to decorate musical instruments. This study focuses on two traditional wood-dyeing procedures carried out with iron–gall dye and iron–logwood dye, respectively. In order to reproduce the ancient techniques, preparation of dyes and their application on two different wood species (poplar and pear) were carried out according to typical ancient recipes and traditions. Wood samples were dyed using mixtures similar to two of the most important historic iron inks, and several specimens (approximately 7 mm in size) were taken and investigated in order to: (1) gain a better insight into the processes involving the dyes and the wood matrices, (2) analyze the effects of the treatments on the anatomical wood structures, (3) evaluate the level of penetration of the dyestuffs into the samples. The analyses were performed after each step of the dyeing procedures, both on the wood samples and on the solutions. Various reaction processes were hypothesized after a micro-Fourier transform infrared spectroscopy analysis, performed in transflection and attenuated total reflection mode. The effects of the various treatments on the wood samples were studied by means of stereomicroscopy, polarized optical microscopy and scanning electron microscopy coupled with energy-dispersive X-ray spectroscopy. The results obtained suggested that both treatments cause alterations in the outer 300 μm of the wooden samples, and that a higher level of penetration was obtained with the hematein complex than with the iron-gall ink
The golden age of the neapolitan lutherie (1750–1800): new insights on the varnishes and decorations of ten historic mandolins
No full textThis paper reports the results of several scientific
analyses carried out on ten mandolins made in the
second half of the eighteenth century by the most important
Neapolitan mandolin manufacturers such as the Filano,
Fabricatore, Gagliano and Vinaccia families. Various elements
of decoration were characterized for each mandolin:
the resins of the sound hole decorations, the black wood
strips of the purflings, the varnishes and the glues. Thanks
to microscopy observations SEM-EDX, lFT-IR and
lRaman analysis, a multi-technique approach was used in
order to fully characterize and compare some of the decoration-making
techniques peculiar of each family of
makers. Shellac was the main organic material used both in
the sound hole decorations and in the varnishes. Inorganic
fillers such as aluminosilicates, particles of iron oxides/
hydroxides and microfossils of diatoms were found within
the false inlays. Black iron-based dyes were identified as
dyes for the black wood strips of the purflings
Experimental characterization of oil-colophony varnishes: A preliminary study
No full textHistorically, the varnishes had the aim to protect the bowed musical instruments by the
external agents and to confer them an aesthetic value. During the 17th and 18th century, in
Italy, the bowed instruments, especially violins, were generally covered by a layer of varnish
made with several natural materials such resins, oil or hide glue: i.e., instruments by the great
violin maker Antonio Stradivari were covered often with a layer of varnish made of linseed oil
and colophony in the ratio 3:1, respectively. The main aim of this work was to study the
modifications that occur in those kinds of varnishes, after exposing them to some factors of
degradation. In order to study the different properties of organic coatings and their suitable
compositions, different mixtures of linseed oil and colophony were recreated in the laboratory
following an ancient recipe: linseed oil and colophony were mixed together with different
ratios (50/50 and 75/25, respectively) and then, they were applied on Maple wood samples and
on glass slides for experimental purposes. In order to investigate the different external factors
which cause the varnish layer degradation, samples were analyzed by different techniques
before and after different ageing processes (thermo-hygrometric cycles, exposition to UV lamp
and to acid vapors). Out of strong experimental evaluation, all the results suggested that the
composition of 75/25 (oil: colophony) is much better as a varnish for musical instruments
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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