Samples were also examined by Quantita-Ray fluorescence spectroscopy by means of a Surface Filmato instrument supplied by Assing

Samples were also examined by Quantita-Ray fluorescence spectroscopy by means of a Surface Filmato instrument supplied by Assing

The XRF spectra were obtained with the following experimental conditions: Mo tube operating at 25 kV voltage and 300 ?A beam current; scan time 120 s; distance 95 mm.

Regarding wood samples, thin sections were obtained according onesto the anatomic wood directions and described following the IAWA list of microscopic features for hardwood and softwood identification [12, 13]. Thin sections of the wood sample were examined under verso Polyvar 100 optical microscope equipped with per PIXeLINK digital parlamento.

Temperature (T) and divisee humidity (RH) values have been recorded through a digital data logger Elenco 177-H1 model. The datazione logger has been calibrated and hanged on the northern wall of presbytery. Datazione have been recorded from 26 of July onesto 8 of September and then elaborated by Excel programma preciso obtain maximum, minimum, average values and norma deviation throughout the analysed period. The temperature and incomplete humidity prova and failure indexes were also calculated and showed mediante the tolerance matrix, con order sicuro obtain verso synthetic expression of the results [14, 15].

Painting material analysis

Stratigraphic and chemical analysis revealed the presence of superimposed layers constituted by several different materials. For this kind of artefacts it is usual esatto find many superimposed painted layers coppia to verso continuous usage of the object that has got verso demo-ethno anthropological significance. Per Figure 5 the ciclocampestre sections of the painting samples are showed. The white layer characterized by an intense yellow fluorescence is constituted by zinc white a pigment widely used starting from 19 th century. According esatto this result it is possible sicuro assess that the surface painted layer was certainly applied during the 19 th or later. The painted layers were applied over gypsum and glue, as revealed by FTIR analysis and UV fluorescence examination of the ciclocampestre sections. Glue exhibits a light blue fluorescence under UV lighting. At last, mediante sample ASN2 and ASN4 an orange UV fluorescence can be observed. This fluorescence can be associated sicuro the presence of shellac, verso natural resin often used with the function esatto isolate the priming or the support before applying the painted layers or the setting respectively.

Results and colloque

Microphotographs of samples ASN1 (A, B), ASN2 (C, D), ASN4 (Di nuovo, livejasmin iscriversi F) and ASN5 (G, H), under reflected light (Per, C, Anche, G) and UV fluorescence (B, D, F, H).

As example of infrared analysis result, the FTIR spectrum of sample ASN1 is showed (Figure 6). The main compound is gypsum with the bands at: 3485 cm -1 , 3400 cm -1 , 1621 cm -1 , 1111 cm -1 , 684 cm -1 and 609 cm -1 . Moreover, calcium carbonate (bands at: 2513 cm -1 , 1797 cm -1 , 1431 cm -1 and 875 cm -1 ), verso siccative oil (bands at 2924 cm -1 , 2854 cm -1 , 1737 cm -1 and 1713 cm -1 ) and iron oxides (peak at 528 and 470 cm -1 ) are present. Durante sample ASN4, also the bands associated preciso proteinaceous compounds have been detected, durante particular the 1540 cm -1 peak paio to amide II [16, 17].

XRF analysis revealed the presence of zinc con all the examined samples but also of lead (Table 2). According preciso this result we can say that the white layer, visible con sample ASN2 and ASN5 ciclocampestre sections was probably made of lead white. This painting was realized previously per respect preciso that made of zinc white. The presence of iron suggests the use of red, yellow and brown ochre. The green grains visible per the ciclocampestre section of sample ASN2 are made of a copper based pigment. Sample ASN3, defined as gilding, contains zinc and copper suggesting the presence of brass powder used puro imitate gold. Arsenic is verso component of the alloy. The use of brass to imitate gold was particularly diffused during the 18 th century, especially esatto produce objects employed on the occasion of popular and traditional festivities .

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