Applying laser induced breakdown spectroscopy (LIBS) and elemental imaging on marine shells for archaeological and environmental research.

Using LIBS for the analysis of archaeological and geological marine mollusc shells is a growing research area that relies on customised instrumentation and specific workflows that can accommodate the variety and precision of the required sampling parameters. However, the increased efficiency offered by LIBS, which enables the study of a larger quantity of shell samples for temperature variation, ecological parameters, and human consumption practices, outweighs the initial efforts required to develop customised instrumentation and workflows. In this work, we present detailed specifications and parameters for the development of a LIBS system capable of generating Mg/Ca images on marine shells that directly correlate with seasonal sea temperatures. Our main objective was to develop specifications that enable easy adaptation of LIBS systems to existing laboratories for studying hard-tissue samples. These specifications were used to develop a customised micro-LIBS system and apply it to a real-world example of an archaeological study to better understand its efficiency on the marine mollusc shells and demonstrate its potential for broader applications in interdisciplinary research. In total 101 shell specimens have been analysed within a time frame of approximately 71 h of machine time, producing 234 images (100 µm resolution: 100 images, 30 µm resolution: 134 images). SEM analysis of the irradiated sections of the shell revealed a primary ablated area of 10-15 µm in diameter, while a secondary affected area of the shell's crystal fabric extended to 30-50 µm after repeated shots. Overall, this new customised system reliably and efficiently analysed marine mollusc specimens without major destructive effects, enabling additional analyses for other proxies to be carried out. This study highlights the potential of the LIBS method for interdisciplinary research, encompassing applications in paleoclimatology, marine ecology, and archaeology.

Non-invasive photoacoustic detection of hidden underdrawings in paintings using air-coupled transducers.

We demonstrate the application of a fully non-contact and non-invasive photoacoustic (PA) imaging system integrating a high sensitivity spherically focused air-coupled ultrasonic transducer, for the uncovering of hidden underdrawings in paintings. By selectively transforming optical absorption information into ultrasonic waves which propagate virtually unobstructed through the paint layers, PA signals provide specific imaging of underlying pencil sketches even for paints presenting high optical scattering and absorption properties. The developed system could be employed for case studies involving the investigation of paintings with historical significance, considerably complementing the capabilities of existing methods.

Photoacoustic imaging reveals hidden underdrawings in paintings.

A novel, non-invasive, imaging methodology, based on the photoacoustic effect, is introduced in the context of artwork diagnostics with emphasis on the uncovering of hidden features such as underdrawings or original sketch lines in paintings. Photoacoustic microscopy, a rapidly growing imaging method widely employed in biomedical research, exploits the ultrasonic acoustic waves, generated by light from a pulsed or intensity modulated source interacting with a medium, to map the spatial distribution of absorbing components. Having over three orders of magnitude higher transmission through strongly scattering media, compared to light in the visible and near infrared, the photoacoustic signal offers substantially improved detection sensitivity and achieves excellent optical absorption contrast at high spatial resolution. Photoacoustic images, collected from miniature oil paintings on canvas, illuminated with a nanosecond pulsed Nd:YAG laser at 1064 nm on their reverse side, reveal clearly the presence of pencil sketch lines coated over by several paint layers, exceeding 0.5 mm in thickness. By adjusting the detection bandwidth of the optically induced ultrasonic waves, photoacoustic imaging can be used for looking into a broad variety of artefacts having diverse optical properties and geometrical profiles, such as manuscripts, glass objects, plastic modern art or even stone sculpture.

Privacy and anonymity in the information society - challenges for the European Union.

Electronic information is challenging traditional views on property and privacy. The explosion of digital data, driven by novel web applications, social networking, and mobile devices makes data security and the protection of privacy increasingly difficult. Furthermore, biometric data and radiofrequency identification applications enable correlations that are able to trace our cultural, behavioral, and emotional states. The concept of privacy in the digital realm is transformed and emerges as one of the biggest risks facing today's Information Society. In this context, the European Union (EU) policy-making procedures strive to adapt to the pace of technological advancement. The EU needs to improve the existing legal frameworks for privacy and data protection. It needs to work towards a "privacy by education" approach for the empowerment of "privacy-literate" European digital citizens.