Lorenzo Pardini

Multi-technique study of a ceramic archaeological artifact and its content

In this paper we report the results of a study performed with different physical and chemical methods on a ceramic vase originally attributed to the I century CE. The joint use of infrared spectroscopic analysis and laser techniques, as well as pyrolysis-gas chromatography coupled with mass spectrometry and thermoluminescence, allowed us to characterize the vase material and its content. The chemical data were combined with morphological and stylistic examinations of the object and helped in defining its actual geographical and chronological pertinence.

Applications of LIBS to the Analysis of Metals

In this chapter we will discuss the basic theoretical principles of the laser ablation process on metal alloys, and will present successful applications of the LIBS technique to the analysis of such materials (aluminium alloys, iron based alloys, copper based alloy, precious alloys, and others). A special emphasis will be given to analytical applications of LIBS performed in line and/or in situ.

Double and Multiple Pulse LIBS Techniques

This chapter will introduce the physical principles underlying double and multiple pulse LIBS analysis and the main applications of this technique for stand-off analysis of hazardous materials, for environmental analysis, for the analysis of biological materials and for cultural heritage and archaeological studies. The available commercial instrumentation for double pulse LIBS analysis will also be presented and discussed.

Element detection relying on information retrieval techniques applied to laser spectroscopy

In this paper, we propose a technique for automatic element detection from Laser Induced Breakdown Spectroscopy (LIBS) spectra. The presented approach uses a technique derived from information retrieval and, more specifically, from the Vector Space Model, to compute the similarity between spectra of elements and samples. These spectra, obtained by LIBS methods, can be represented as sequences of peaks of light emissions of specific wavelengths and intensities. In text retrieval, vectors are built using terms of the vocabulary and weight assessing the relevance of terms in documents or queries. In our case, peaks play the role of terms, elements that of documents, and samples that of queries. We will discuss how to define vectors, weights, and similarity between spectra. Experiments prove the validity of the method.

Modi: a new mobile instrument for in situ standardless LIBS analysis of cultural heritage

Laser-Induced Breakdown Spectroscopy (LIBS) is a promising technique for in-situ analysis of Cultural Heritage. The potential of this technique for accurate quantitative analysis could be greatly improved using an innovative experimental setup - based on the use of two laser pulses suitably retarded - and analyzing the results with a standard-less procedure which overcomes the problems related to matrix effects. A new mobile instrument for Cultural Heritage analysis, developed at the Applied Laser Spectroscopy Laboratory in Pisa, is presented, and some experimental results are given.