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La Madonna con Bambino, i Santi Geronzio, Maria Maddalena e Donatori conservata presso il Pio Sodalizio dei Piceni in Roma. Studio, restauro e indagini scientifiche
No full textL'articolo descrive le indagini scientifiche realizzate sul dipinto conservato presso il Pio Sodalizio dei Piceni in Roma
A scientific approach to the characterization of the painting materials of Fra Mattia della Robbia polychrome terracotta altarpiece
No full textDuring the last restoration (2008–2011) of the polychrome terracotta altarpiece called Coronation of Virgin between Saints Rocco, Sebastian, Peter martyr and Antonio abbot, located in the collegiate church of S. Maria Assunta in Montecassiano (Macerata, Italy), scientific investigations were carried out to acquire detailed information about the painting technique. The identification of materials allowed a correct restoration.
The altarpiece is almost entirely realized by Marco della Robbia (Fra Mattia), dates back to the first half of the XVI century and represents an interesting example of painted terracotta produced by using two different techniques: glazed polychrome terracotta and the “cold painting” technique.
The characterization of the samples’ material constituents was obtained by analysing the cross-sections and the frag- ments by different techniques (optical, SEM-EDS and ATR- FTIR microscopy as well as GC-MS), as the real nature of a component is often difficult to assess with one single technique.
The optical microscope examination of paint cross- sections shows the presence of many layers, indicating the complexity of the paint stratigraphic morphologies. The original polychromy of della Robbia’s masterpiece is constituted of cinnabar, red lake, red lead, orpiment, red ochre, lead white, lead tin yellow, green earth and raw umber. Two different types of gilding technique have been distinguished. The first one presents a glue mordant, and the second one shows an oil mordant composed by a mixture of red lead, red ochre, cinnabar and orpiment. The GC-MS analysis al- lowed the characterisation of linseed oil and a mixture of an- imal glue and egg as binding media stratigraphically located by the use of ATR-FTIR mapping microscopy. The analytical results of the painted terracotta integrated investigations show that original technique adopted is characterised by the application of pigments in an oil-binding medium directly applied on the substrates, probably treated with oil and ani- mal glue.
A large number of overpaintings above the original scheme of polychromy was found, which could be ascribed to almost three different interventions; the absence of modern pigments suggests that they could be realized long ago
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
The altarpieces of Della Robbia atelier in Marche region: investigations on technology and provenance
No full textDissemination of Della Robbia glazed terracotta in the Marche (Italy) region started from the third decade of the 16th century. Numerous altarpieces, some of which no longer exist, document this artistic production. The protagonists of this diffusion phase were two of Andrea Della Robbia's sons, Marco (Fra Mattia) and Francesco (Fra Ambrogio).
This paper shows the results of the scientific investigations carried out on constitutive materials of different altarpieces located in South Marche belonging to the Fra Mattia's production: the Coronation of Virgin between Saints Rocco, Sebastian, Peter martyr and Antonio abbot, dated back to 1527-30, located in the collegiate church of S. Maria Assunta in Montecassiano; the Annunciation, dated back to 1520, placed in the church of S. Maria del Soccorso in Arcevia; the fragmentary Crowned Madonna and saints altarpiece, probably realized after 1531, today preserved in Civic Museum of Ripatransone.
The first altarpiece was made in Montecassiano using two different assembling or production techniques: the external part of the lunette and the pillar strips are made of glazed polychrome terracotta, while the altar step and the internal part are an interesting and uncommon example of polychrome painted terracotta. The provenance of the glazed Arcevia altarpiece is not clear yet: some historians hypothesize a local manufacture of Fra Mattia and some others a Roman or Florentine production. The remaining parts of Ripatransone altarpiece are partially glazed and partially not coated perhaps because they were unfinished and not yet painted.
Clay body samples collected from the above mentioned altarpieces were investigated using different analytical techniques (OM, XRD, XRF, PIXE) to point out differences in chemical and mineralogical composition and to determine if the altarpieces were made by using local raw clay materials or other clays from Tuscany or Campania as in the Della Robbia previous production. A comparison has also been made with literature data on the Della Robbia terracotta masterpieces.
From the chemical point of view, the clay bodies show a good compositional homogeneity and result calcium and iron-rich according with the raw local materials. The presence of gehlenite, pyroxenes, and hematite and the incomplete decomposition of clay minerals indicate that firing for all different terracotta parts occurred in a thermal range between 800 and 950° C, mostly in oxidizing conditions
Invasive and non-invasive analyses for knowledge and conservation of Roman wall paintings of the Villa of the Papyri in Herculaneum
Full text linkThe Villa of the Papyri is one of the most imposing architectural examples of Herculaneum dated before the eruption occurred on 79 A.D. During the earliest years of the excavation of the site (18th century), the Villa has been explored through a thick network of tunnels dug into the hard bank of tuff rock. Recent excavations went on discontinuously between 1990s and 2008, until the discovery of a room located in the lower floor of the build- ing, showing serious phenomena of colour change of some areas of the painted walls. Some dark green parts of mural paintings after volcanic mud removal became white and powdered, detaching from the plaster.
During the last restoration works a scientific approach became necessary in order to acquire detailed information about the wall painting technique and the degradation phenomena occurring in some decorative elements in the vault of the Basis Villa (a room in the lower floor of the building); it was established to perform a scientific recognition.
Integrated investigations – carried out by optical microscopy, scanning electron microscopy with X-ray microanalysis (EDS), X-ray diffractometry (XRD), ion chromatography (IC), FT-IR spectroscopy, gas chromatog- raphy mass spectrometry (GC-MS) – had primarily the goal to characterize the materials used for the realization of the these impressive wall paintings, as well as to assess their state of conservation.
A second aim of the research was to test the reliability of non-invasive analyses that are sometimes performed in situ to study mural paintings, like reflectance spectrometry in the visible range (vis-RS), X-ray fluorescence (ED-XRF) and micro-Raman spectroscopy, as well as imaging analyses like false colour IR (IRC) and visible induced IR luminescence (VIL).
The whole set of analyses allowed to identify a typical Vitruvian plaster with the following pigments: Egyptian blue, red and yellow ochre, goethite and hematite particles, green earth and carbon black particles.
The high content of soluble salts, which is related to the sulphur-rich water in the site located few metres above water level in the walls and floors, caused a worsening in the state of conservation of mural paintings
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