1,721,010 research outputs found
A scientific and historical investigation on Italian scagliola
No full textFragments from works of art made of scagliola, a material typical of northern Italy imitating marble, were investigated. Thefragments are representative of art objects that were once widespread in the region centred on the town of Carpi. Vibrationalspectroscopic techniques were applied in order to identify the pigments used to tint the gypsum paste; in particular, Ramanmicroscopy was used for the identification of pigment particles. Pyrolysis gas chromatography combined with mass spectroscopy wasused to identify binding media. Several documents were examined, both ancient and recent, preserved in local archives, describingthe pigments and dyes and the techniques used in the preparation of scagliola. The information provided in these documents wascompared to results obtained from scientific analysis
Diagnostics on Scagliola Altar Frontals from the Area of Modena (Italy)
No full textTraditionally, the town of Carpi is considered the home of scagliola. The old attestations of scagliola masters starting from the 16th century and the presence on the spot of hundreds of altar frontals and other lithurgical and domestic objects testify this tradition, besides the presence of a Municipal Museum of Scagliola in the Castle of Pio family. The art of scagliola developed from the simple white-and-black artifacts to the polychrome altar frontals and tables whit elaborate workmanship, and spread beyond the Modena area, as it is testified by both the works in adjacet provinces and regions, and the propagation of schools whit the transfer of masters outside the Emilia region. Recent studies carryed out by means of non destructive techniques have put in evidence the correspondences among the techniques identified for the preparation of the artifacts and the literature sources. Some more manuscripts preserved in the Archivio Storico of Carpi and amounting to the age of the ruling by the Pio family, indicate a series of materials for preparing the support and the coloured dough. We report the results of a research carried out by means of different analytical methods for the identification of the materials employed in the execution of these artefacts. The research was carried out in order to identify some more correspondences between measurements and old sources and to ascertain possible differences among ateliers or schools. Whereas Raman microscopy enabled to find out the pigments and dyes used for the scagliola, Gas-Chromatografy coupled whit Mass Spectrometry gave micro-distructively information on the nature of binders and of the products for the surface finish. The application of these techniques to the study of some altar frontal samples from the area of Carpi, Modena and Reggio has led to the identification of pigments such as minium, vermillon, lazurite, orpiment, red and yellow ochres, lead white and lampblack, and of dyes such as indigo, saffron, and of a red dye with a clear spectrum, but unknown nature. The binder corresponds to an animal glue that is locally known as “colla garavella” or “german glue”, the preparation of which is reported in many medieval and Renaissance recipe-books
Caratterizzazione delle pitture murali della necropoli di Sos Furrighesos (Anela, Italia)
No full text
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
Studio di preparati farmaceutici del XVIII-XIX secolo tramite GC/MS e HPLC-DAD
No full textIl presente lavoro è volto allo studio e alla conoscenza chimica delle sostanze organiche naturali impiegate nella realizzazione di antichi preparati farmaceutici. Questa ricerca è stata svolta nell'ambito del progetto nazionale PRIN07 dal titolo "Colori e balsami nell'antichità: dallo studio chimico alla conoscenza delle tecnologie in cosmesi, pittura e medicina". In questa sede verranno mostrati i risultati ottenuti dallo studio di preparati antichi provenienti dal Museo di Aboca di S. Sepolcro (AR), della Real Cartuja de Valdemossa (Palma di Maiorca) e del Museo di S. Agostino (Palazzo Tursi, GE). A causa della complessità della composizione chinica delle matrici sono state scelte per l'analisi della componente organica tecniche cromatografiche e in particolare la gas cromatografia accoppiata alla spettrometria di massa (GC/MS) e la cromatografia liquida ad alta pressione con rivelatore a serie di diodi (HPLC-DAD). Queste tecniche permettono la separazione e l'identificazione delle singole specie chimiche presenti e tra queste il riconoscimento di markers bio-molecolari. La combinazione dei dati ricavati dalle analisi di sostanze naturali sottoposte a invecchiamento, di unguenti riformulati seguendo ricettari e documenti d'epoca hanno permesso la caratterizzazione delle sostanze prese in esame e a migliorare la conoscenza della farmacopea antica. La presenza di diverse classi di composti, in particolare di acidi grassi mono- e poliinsaturi a catena corta e a catena lunga, diacidi, idrossiacidi, alcol a catena lunga, n-alcani a catena lunga e acidi diterpenoidi hanno evidenziato tre diversi tipi di sostanze: cera d'api, olio vegetale e resina di pino
Spectroscopic Characterization Of Ancient Matrices
No full textSince a decade our research group deals with the analysis of ancient cosmetics and drugs, starting from the Roman founds 1-3. Actually, this kind of study involves other research groups supported by a national Fund (PRIN: Colours and ointments in antiquity). Firstly the analysis protocol provides non-destructive analyses and then the more expensive and destructive analyses, such as gas-chromatography-mass spectrometry (GC-MS) methods. The samples analyzed in this study were collected from the Egyptian Museum of Turin, Italy. The discovery of the studied archaeological finds was made by Ernesto Schiaparelli (1906 until 1913) and the archaeological founds were dated from the late III millenium b.C. to early II millenium b.C. The sites of finding were in Assiut (at about 400 Km from Cairo on the bank of the Nile) and Gebelein (south of Assiut), near the southern border with Nubia. In the sarcophagus usually it is possible to find weapons, like bows and arrows, textiles and also ointments. Here the results of the vibrational spectroscopy techniques, such as Raman microscopy (laser 632 nm), FT-Raman spectroscopy (laser 1064 nm) and FT-IR/ATR with a golden gate accessory are reported. These techniques are identified as the most suitable ones for the first approach to ancient samples analysis. Raman microscopy is in fact the most suitable technique in order to identify minor inorganic components and contaminants at the micrometric scale inside these complex matrices4. This technique can easily identify compounds like lead oxide, vermillion, rare minerals, (etc.) that could give interesting informations about the provenance of the raw materials and the original composition of the formulate. In the present study some data are reported concerning the composition of five ancient Egyptian samples. It can be observed that Titanite is present, a mineral possibly coming from mines in Southern Egypt5.Concerning to organic materials, their possibility of identification, is very different from that of inorganic ones. Some compounds were rapidly degraded, some others persisted till to present day, often unchanged (e.g. wax). Historical samples give a chemical variability due to the natural products, in addiction, ageing and degradation processes make very difficult to recognize raw materials originally present. For understanding the possible changes undergone by materials in ageing, a specific database of spectra must be available. Some thirty raw materials were chosen among oils, gums, animal fats and waxes commonly employed in the ancient preparations. The reference materials were in laboratory artificially aged by heating, photo-oxidation and enzymatic degradation. Some artificial materials aged produced different alterations according to the type of ageing. The comparison to one remain sample and our database spectrum showed a correspondence with the enzymatically degraded palm oil spectrum. This indicates the importance of this database in recognising the organic materials into archaeological holders
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