Stefan Simon

Testing methods and criteria for the selection/evaluation of products for the conservation of porous building materials

Abstract This paper is a review of the literature that addresses the testing of products and tools for stone conservation. Cleaning products and tools are considered, as are products for consolidation and for the surface protection of natural and artificial stones (e. g., mortars or bricks). After an outline of the historical development of testing methods from the mid-nineteenth century to the present day, the development of the field is discussed with particular regard to the parameters that are measured, the measuring methods and evaluation criteria. This paper also discusses the weaknesses still existing in current methodologies, the aspects that should be investigated in greater depth and the increasing use of non-destructive testing methods to improve the evaluation of the long-term performance of treatments.

Ultrasonic testing for the investigation and characterization of stone – a non-destructive and transportable tool

Abstract This paper reviews the use of ultrasonic testing as a non-destructive tool for the investigation of stone and the evaluation of conservation treatments. Various investigation techniques and applications are presented and current trends in research are discussed. An increasing emphasis on the relationship between stone fabric parameters and the results of ultrasonic tests is clearly evident. This review highlights several points that should be considered when applying ultrasonic testing for the investigation of stone.

Removal of Particulate Contamination from Solid Surfaces Using Polymeric Micropillars

This Research Article describes a novel method for removal of particulate contamination, loosely referred to as dust, from solid surfaces using polymeric micropillars. In this Research Article, we illustrate for the first time that polymeric microfibrils of controlled interfacial and geometrical properties can effectively remove micrometric and submicrometric contaminant particles from a solid surface without damaging the underlying substrate. Once these microfibrils are brought into contact with a contaminated surface, because of their their soft and flexible structure, they develop intimate contact with both the surface contaminants and the substrate. While these intrinsically nonsticky micropillars have minimal interfacial interactions with the substrate, we show that they produce strong interfacial interactions with the contaminant particles, granting the detachment of the particles from the surface upon retraction of the cleaning material. The origin and strength of the interfacial interactions at the interfaces between a contaminant particle and both the substrate and the cleaning materials are thoroughly discussed. Unlike flat substrates of the same material, using microfibrillar structures of controlled interfacial and geometrical properties also allows the elimination of the adsorbed particles from the contact interface. Here we demonstrate that by moving the adsorbed particles from the tip to the side of the fibrils and consequently removing them from the contact interface, polymeric microfibrils can clean all contaminant particles from the surface. The effects of the geometrical and interfacial properties of polymeric micropillars on removing the adsorbed particles from the tips of the pillars are fully discussed. This research is not only important in terms of introducing a novel method which can offer a new paradigm for thorough yet nondestructive cleaning of dust particles from solid surfaces, but also it is of fundamental significance for researchers with interests in exploiting the benefits offered by microstructured surfaces in development of interfacially active materials and devices.

PANNA project --- plasma and nano for new age soft conservation. development of a full-life protocol for the conservation of cultural heritage

EU PANNA project started on November 2011 and aims at integrating a novel atmospheric plasma technique for surface cleaning and two innovative coating typologies (self-diagnostic protective coatings and identification marker coating) in a full-life protocol spanning surface cleaning, deposition of coatings and their complete removal. The validation of the protocol will be achieved through the cooperation between conservation scientists and technological companies. In the project, the development and testing of the protocol will be performed on two categories of substrates: metals (bronze and silver) and stone and stone-like materials (limestone, sandstone and wall paintings). The development will be performed on laboratory prepared samples (dummy or replica or mock ups) and also on real objects.

Ultrasonic phased array technology for the non-destructive testing of marble sculptures

The medical ultrasonic phased array technology was modified for the non-destructive testing of marble sculptures and the feasibility of the approach was evaluated. For this purpose, 1 MHz, 64-channel phased array electronic and phased array transducers were developed. The specifications of the electronics and the transducers are presented and discussed. Ultrasound images of inner structures of a marble sculpture are presented. The problem of the acoustic matching layers for different states of deterioration is discussed and the developments in view of a suitable matching layer solution are presented. This matching layer is combined with a new coupling technique that protects the marble surface. The results of experiments on ultrasound phantoms and on a marble sculpture are presented.

QR Coded 3D Prints of Cuneiform Tablets

This article discusses the design of a quick response (QR) coded 3D model of a Babylonian mathematical clay tablet for 3D printing purposes, in an attempt to make better use of advanced 3D visualizations, encourage public engagement and question the influence of tagging and 3D printing on the way humans interact with ancient documentary artefacts. The main emphasis of this article is the methodological challenge, taking under consideration both the technical constrains and object-oriented requirements, such as aesthetics and authenticity. The proposed methodology for the successful implementation of the project incorporates 3D modelling, 3D printing, Automatic Identification Data Capture (AIDC) technologies, and a new open source platform named Cultural Heritage Object (CHER-Ob), for data management, decision making and scientific collaboration.