Search

We report a non-invasive and multi-analytical physico-chemical method for the characterization of paper artworks, able to identify sizing, inks, and glues and to quantify oxidative degradation by-products. The proposed methodology is mostly carried out in situ by using easy-to-use and cheap portable instrumentation for the acquisition of multispectral images, punctual ultraviolet-visible-near infrared fiber-optics reflectance spectroscopy (FORS) and punctual fiber optics fluorescence spectroscopy. Further analytical information is provided by non-invasive in-situ sampling of paper surface by using soft latex sponges, making possible laboratory chromatographic and infrared spectroscopic analyses on the aqueous sponge extracts. The proposed diagnostics method was applied to two 17th century letters written by St Francis of Sales (1567-1622), collected at the Chigi Palace in the town of Ariccia (Italy). Results show an intense oxidative degradation of the letters, also localized in water spots, and the presence of carboxylic acids by-products. Analysis of FORS spectra provided the concentration of chromophores in the paper substrate. The diagnostic method allowed the identification of gelatin sizing, the presence of starch glue in specific areas of the letters and the type of ink used in the text. Our diagnostic approach aims to offer to conservator-restorer a characterization of a paper artwork, that can be applied to other, for a correct planning of conservation interventions.

Tokens are digital, transferable and programmable assets and one of the most promising tools offered by blockchains. They could enable a wide range of applications, from down to earth to futuristic. One of the main issues in achieving wide adoption of tokens is onboarding: main platforms require users to deal with specific tools such as wallets, transaction fees, key generation and storage. The most common solution to offer a familiar experience to naive users are custodial intermediaries, which have the important drawback of centralizing the process, and keeping users away from the advantages of self-sovereign assets control. In this paper we present a process for the distribution of digital tokens to end users, exploiting “physical” objects for initial distribution. The process is aimed at making onboarding of users not yet accustomed with blockchain tools and concepts as easy as possible, in a secure and decentralized way.

Wet cleaning of paper artworks by using hydrogels is a recently proposed process in the cultural heritage field. In this contest, on one side, research has focused on more effective and tuned cleaning hydrogels; on the other, the cleaning performances of the proposed hydrogels have been studied on ancient paper and very little on modern paper. This lack of information is not negligible, since the two kinds of paper differ strongly in composition. The difference, in turn could affect the performance of cleaning gels. In this article, new chemical hydrogels were synthetized using an oxidized polyvinyl alcohol (PVA) bearing an aldehyde group at each chain end, as cross-linking agent, i.e. telechelic PVA. PVA hydrogels have been characterized as candidates for paper cleaning applications. The possibility of tuning the mechanical and retentive properties, simply by changing the ratio of two polymer concentrations, their stability and transparency, indeed, render them, potentially suitable in cultural heritage field. The cleaning capability of two hydrogels, with different PVA/telechelic PVA ratios, has been assessed both on ancient paper, than a modern one and the results have been compared. The efficacy of these hydrogels has been demonstrated characterizing the samples before and after the cleaning process by means of a multidisciplinary approach involving spectroscopic and chromatographic tests.

Tokens are digital, transferable and programmable assets and one of the most promising tools offered by blockchains. They could enable a wide range of applications, from down to earth to futuristic. One of the main issues in achieving wide adoption of tokens is onboarding: main platforms require users to deal with specific tools such as wallets, transaction fees, key generation and storage.The most common solution to offer a familiar experience to naive users are custodial intermediaries, which have the important drawback of centralizing the process, and keeping users away from the intrinsic advantages of blockchains.In this paper we present a process for the distribution of digital tokens to end users, exploiting "physical" objects for initial distribution. The process is aimed at making onboarding of users not yet accustomed with blockchain tools and concepts maximally easy, in a secure and decentralized way.