English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Scientific research regarding the conservation of gypsum plaster heritage is quite scarce; cleaning is often a problematic issue on this kind of material due to its water sensitivity and mechanical features. Therefore, laser cleaning is often a good option as some recent paper has reported. The research presented here focused on laser cleaning on three gypsum plaster casts belonging to the collection of Brera Fine Arts Academy and dated back to the 19th century; recalling the names of the original marble statues, the items are the Flora Farnese, The Velletri Pallas and the Barberini Faun. The three casts had been exposed for many decades in the entrance hall of the Academy in a semi-confined environment. Unfortunately, the continuous passage of students soiled the plaster surface with a grey greasy layer localized especially on the lower parts and on the surfaces with a strong horizontal component. It was possible to identify a superficial grime and traces of the original patina. Marks of different nature (felt, pen, pencil, scratches) were also present. Cleaning tests were carried out using Thunder Art Nd:YAG able to emit both at 1064 nm and at 532 nm. The effects of laser cleaning were studied with a diagnostic campaign carried out both before and after the cleaning operation. To define the aspects and the nature of the surface microsamples were sampled and analysed with XRD, XRF, then observed with a scanning electron microscope SEM, and with optical microscopy. Several tests were carried out on the Flora Farnese, calibrating the fluence in order to match the ablation threshold avoiding any damage (from FL=1 – 1,45 J/cm2 at 1064 nm to FL = 0,5 – 0,7 J/cm2 at 532 nm with repetition rate from 6 Hz to 10 Hz) in particular on these surfaces the removal of cement splashes constituted a hard task. A comparison in between tests at 1064 nm and at 532 nm were performed. Both tests were evaluated with the aid of humidification with free water (applied with brush) and with the use of AgarArt® rigid gel. On the basis of laser-plaster interaction observed on the Flora, the tests on the other casts excluded the IR radiation, because of a yellowing effect. For what regards the cast of the Pallas, one of the low relieves in the wooden support base was involved. The laser cleaning allowed the perfect removal of the outer layers of scialbo. For the cast of the Faun, laser cleaning proved to be the appropriate system to eliminate greasy deposits and dark grey stains visible on the irregular surface, maintaining the original morphology. Hence it was possible to avoid invasive mechanical and chemical systems, minimizing the interaction with the matter and saving working time. The aim of this work is to provide a contribution to the scientific

Experiences at the Academy of Fine Arts of Brera in Milan, Italy: the application of laser-technology on three case studies of the historical heritage