1,720,980 research outputs found
The joined use of n.i. spectroscopic analyses – FTIR, Raman, visible reflectance spectrometry and EDXRF – to study drawings and illuminated manuscripts
No full textSome art objects being small and very precious
prevents conservators and conservation scientists from whatever kind of sampling, so that only completely non-invasive
(n.i.) studies are permitted. Besides, also moving the object
is sometimes forbidden: this happens for jewels as well as
for manuscripts, illuminated codices, drawings and paintings.
Some important physical n.i. analyses, such as PIXE and PIGE,
therefore cannot be used in many cases. With these limitations, only imaging techniques in X, UV, Visible and IR bands,
and a few spectroscopic methods that can be carried out with
portable instruments can be applied, i.e. molecular spectroscopies like Fourier transform infrared (FTIR), Raman, UV
visible and near IR reflectance spectrometry (UV-Vis-NIR RS)
and atomic spectroscopy like energy dispersive X-ray fluorescence (EDXRF).
The use of only one or two of these techniques is usually
far from giving all the information required to achieve a full
characterization of materials used by the artist or during restorations, and to understand some conservative problems of the
object. On the contrary, a joined use of n.i. analyses can supply a larger set of data, allowing for cross checks. With this
aim we show a fully integrated spectroscopic approach to polychrome objects, and, in particular, to drawings and illuminated
manuscripts, using portable instruments, specifically μ-FTIR,
μ-Raman, Vis-RS and EDXRF, where also the Raman signal
does not suffer fluorescence caused by varnish coating and from
binder.
We propose the joined use of all these four physical analyses
to characterize materials – support, pigments, dyes, binders, etc.
– on a complex case: a painted and drawn parchment of the late
15th century, or the beginning of the 16th, partly attributed to
Andrea Mantegna. The collected spectroscopic data have been
compared to proper spectral databases, some of which specifically realized in our laboratories. Also, mixtures of pigments
and their stratigraphical sequence have been detected, as well
as important data related to the manufacturing and the type of
iron-gall ink
La materia del zogielo. La Madonna della Tenerezza secondo le analisi non invasive integrate
No full textThe joined use of n.i. image and spectroscopic analyses – FTIR, Raman, visible spectrometry and EDXRF – to study a complex painted and drawn parchment
No full textA non invasive method to detect stratigraphy, thicknesses and pigment concentration of pictorial multilayers based on EDXRF and vis-RS: in situ applications
No full textEnergy dispersive XRF analysis (EDXRF) in association with visible reflectance spectroscopy (vis-RS), both achieved by portable instruments, can be successfully applied, in a wide range of cases, to investigate wood or canvas paintings in order to obtain some stratigraphic information with non-invasive techniques. The specific aim of this work is to use them as quantitative tools: EDXRF to reconstruct the thicknesses of the detected layers, vis-RS to report pigment concentration in the uppermost layer. The method has been tested in the laboratory on paint layers with different composition of about 50 multilayers and more than 100 single layers [12]. We present here some in situ analyses of famous paintings by Andrea Mantegna and Giovanni Bellini, compared with stratigraphic optical microscopy observations on cross sections. Advantages and limits are pointed out
Heat Diffusion in Klinker Facade: The Study Case of a Gio Ponti Building
Full text linkThe researchers focus on the IRT procedure of heat diffusion in ceramic finishing materials of contemporary architecture. The aim of the research is the development of a method for the thermal characterization of clinkers, a very common ceramic finishing material of buildings. The first experimental phase was performed in laboratory on clinkers of different shapes, thickness, colors, and glazing surface. The researchers determined two characteristic parameters related to thickness and thermal conductivity, by the interpolation of the heating curve in function of time with an analytical curve (resulted from a particular solution of Fourier's equation). This curve allows to obtain a parameter characteristic of the material of the specimens under investigation. At present time, the researchers have been studying the correlation between this parameter and the damage level in the specimens; they will be testing the model on real-scale study cases in the second experimental phase
Conoscere per conservare. Analisi non invasive sui disegni palladiani dei Musei Civici di Vicenza
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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
Comparison of three portable EDXRF spectrometers for pigment characterization
No full textIn the field of cultural heritage analyses, energy dispersive X-ray fluorescence is a well known nondestructive technique used—among other applications—to characterize pigments and inks in artifacts such as paintings, polychromous sculptures and illuminated manuscripts. In this paper, we report on the performance of three portable X-ray fluorescence analyzers currently used for laboratory or in situ analyses. The three spectrometers have been tested in laboratory on paint layers prepared to simulate real ones, with the specific goal to determine advantages and disadvantages for each instrument in the detection of specific elements characterizing the pigment. Additionally, overall general advantages and limitations of each system in practical use are highlighted
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
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