Comparison of x-ray absorption and emission techniques for the investigation of paintings

Transmission radiography is an excellent and easy to use method to visualize the internal structure and spatial distribution of heavy Z pigments in the paint layer of 15th to 17th-century panel paintings. It is used to examine the creation process of the artist (e.g. changes in composition, underlying paintings, etc.), to identify older restorations and to solve authentication problems. However, some historical paintings have white lead-based preparatory layers. As a result, the pictorial layer can hardly be visualized in the radiographic images. This problem becomes even more important for 19th and 20th-century paintings due to the introduction of low-Z white pigments. In this investigation, we explored the possibilities of 4 less common radiographic techniques in order to circumvent the mentioned problems. For this, we applied the techniques on 4 panel paintings with an identical figurative composition made by the artist Peter Eyskens

Trace elements in phases of the Sikhote-Alin iron meteorite

A sample of the IIAB iron meteorite Sikhote-Alin has been studied for trace elements in the metal and troilite phases using electron microprobe analysis, radiochemical neutron activation analysis, and secondary ion mass spectrometry. Comparison with other members of the IIAB iron group shows that this is a typical IIAB meteorite, and fits quite well in the group, which shows a wide variations of the content of some trace elements. The variation and also the distribution coefficients of some trace elements between metal and sulphide is not consistent with a simple fractional crystallization model

TOMCAT: A MATLAB toolbox for multivariate calibration techniques

We have developed a new user-friendly graphical interface for robust calibration with a collection of in-files, called TOMCAT (TOolbox for Multivariate CAlibration Techniques). The graphical interface and its routines are freely available and programmed in MATLAB 6.5, probably one of the most popular programming environments in the chemometrics community. The graphical interface allows a user to apply the implemented methods in an easy way and it gives a straightforward possibility to visualize the obtained results. Several useful features such as interactive numbering of the displayed objects on a plot, viewing the content of the data, easy transfer of the data between the toolbox and the MATLAB workspace and vice versa, are also implemented. Among the implemented methods there are Principal Component Analysis and its robust variant, Partial Least Squares, Continuum Power Regression, Partial Robust M-Regression, Robust Continuum Regression and Radial Basis Functions Partial Least Squares. (c) 2006 Elsevier B.V. All rights reserved.status: publishe

Feasibility of Fourier transform laser microprobe mass spectrometry for the analysis of lubricating emulsions on rolled aluminium

Additives from lubricating emulsions used in the rolling step of aluminium plate production, are suspected to adhere to the surface and change the surface properties of the metal. The present study aims at investigating the feasibility of a Fourier transform laser microprobe mass spectrometer with external ion source to characterize the organic components at the metal surface. Special attention is given to the possible interactions between the additives and the aluminium. The experiments primarily involve model systems, consisting of aluminium with a thin coating of the individual components or of laboratory-made mixtures.SCOPUS: ar.jFLWINinfo:eu-repo/semantics/publishe

Development and in vitro testing of gelatin-based antibacterial burn wound dressings

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