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 per Polyvar 100 optical microscope equipped with a PIXeLINK digital parlamento.
Temperature (T) and imparfaite humidity (RH) values have been recorded through verso digital datazione logger Elenco 177-H1 model. The tempo logger has been calibrated and hanged on the northern wall of presbytery. Giorno have been recorded from 26 of July preciso 8 of September and then elaborated by Excel software esatto obtain maximum, minimum, average values and standard deviation throughout the analysed period. The temperature and correlative humidity esibizione and failure indexes were also calculated and showed sopra the tolerance matrix, durante 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 onesto find many superimposed painted layers due preciso per continuous usage of the object that has got per 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 per pigment widely used starting from 19 th century. According preciso this result it is possible preciso 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 ciclocross sections. Glue exhibits verso light blue fluorescence under UV lighting. At last, durante sample ASN2 and ASN4 an orange UV fluorescence can be observed. This fluorescence can be associated puro the presence of shellac, a natural resin often used with the function sicuro isolate the priming or the support before applying the painted layers or the setting jackd respectively.
Results and conciliabule
Microphotographs of samples ASN1 (Per, B), ASN2 (C, D), ASN4 (E, F) and ASN5 (G, H), under reflected light (Verso, C, Addirittura, 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 ), a 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 esatto proteinaceous compounds have been detected, durante particular the 1540 cm -1 peak coppia onesto amide II [16, 17].
XRF analysis revealed the presence of zinc sopra all the examined samples but also of lead (Table 2). According puro this result we can say that the white layer, visible per sample ASN2 and ASN5 ciclocampestre sections was probably made of lead white. This painting was realized previously in respect to 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 verso copper based pigment. Sample ASN3, defined as gilding, contains zinc and copper suggesting the presence of brass powder used to imitate gold. Arsenic is verso component of the alloy. The use of brass puro imitate gold was particularly diffused during the 18 th century, especially puro produce objects employed on the occasion of popular and traditional festivities .