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Sawoszczuk T.,Cracow University of Economics | Sygula-Cholewinska J.,Cracow University of Economics | del Hoyo-Melendez J.M.,Laboratory of Analysis and Non Destructive Investigation of Heritage Objects
Journal of Chromatography A

The main goal of this work was to optimize the SPME sampling method for measuring microbial volatile organic compounds (MVOCs) emitted by active molds that may deteriorate historical objects. A series of artificially aged model materials that resemble those found in historical objects was prepared and evaluated after exposure to four different types of fungi. The investigated pairs consisted of: Alternaria alternata on silk, Aspergillus niger on parchment, Chaetomium globosum on paper and wool, and Cladosporium herbarum on paper. First of all, a selection of the most efficient SPME fibers was carried out as there are six different types of fibers commercially available. It was important to find a fiber that absorbs the biggest number and the highest amount of MVOCs. The results allowed establishing and selecting the DVB/CAR/PDMS fiber as the most effective SPME fiber for this kind of an analysis. Another task was to optimize the time of MVOCs extraction on the fiber. It was recognized that a time between 12 and 24. h is adequate for absorbing a high enough amount of MVOCs. In the last step the temperature of MVOCs desorption in the GC injection port was optimized. It was found that desorption at a temperature of 250. °C allowed obtaining chromatograms with the highest abundances of compounds. To the best of our knowledge this work constitutes the first attempt of the SPME method optimization for sampling MVOCs emitted by molds growing on historical objects. © 2015 Elsevier B.V. Source

Troalen L.G.,United Road Services | Rohrs S.,Rathgen Forschungslabor Staatliche Museen zu Berlin | Kunz S.,Rathgen Forschungslabor Staatliche Museen zu Berlin | del Hoyo-Melendez J.M.,Laboratory of Analysis and Non Destructive Investigation of Heritage Objects
Microchemical Journal

Non-European dyed materials other than textiles have received comparatively little systematic analysis, this is particularly true for objects made with dyed porcupine quills. This paper presents a comprehensive study of a group of Athapaskan porcupine quill specimens collected in 1862 which are held within the collections of National Museums Scotland, UK. Due to sampling limitations micro-destructive testing, or non-invasive analysis using PDA-UPLC, Raman Spectroscopy and PIXE were used to characterise the dye sources and metallic mordants. RBS was used to obtain additional information on the depth-profiling of the mordants in the keratin-based quill. The sensitivity of the quill specimens to photo-degradation was evaluated using Micro Fade Testing (MFT). The results from this multi-analytical study will be used to inform future display regimes of this unique collection. © 2015 The Authors. Source

Klisinska-Kopacz A.,Laboratory of Analysis and Non Destructive Investigation of Heritage Objects
Journal of Raman Spectroscopy

X-ray fluorescence spectroscopy (XRF) and Raman spectroscopy analysis were performed to examine a 17th century painted silk banner in order to characterize the pigments and materials used. This complementary approach yields information on the elemental (XRF) and on the molecular composition (Raman) of the used compounds. The paint layer, ground layer under gilding, and gilding layer were investigated. For the studied object, vermilion (HgS), lead white (2PbCO3 · Pb(OH)2), red lead (Pb3O4), and aurichalcite ((Cu,Zn)5(CO3)2(OH)6) were found. The presence of silver and gold foils was confirmed. The techniques used in the analysis were portable, non-destructive, and non-invasive, which is very desirable when analyzing cultural heritage objects. The obtained results were used by the conservators to develop a showcase prototype for safe exhibition. Copyright © 2015 John Wiley & Sons, Ltd. Source

Gancarczyk J.,University of Bielsko Biala | Sobczyk J.,Laboratory of Analysis and Non Destructive Investigation of Heritage Objects
Foundations of Computing and Decision Sciences

In this paper a new approach to image segmentation was discussed. A model based on a data mining algorithm set on a pixel level of an image was introduced and implemented to solve the task of identification of craquelure and retouch traces in digital images of artworks. Both craquelure and retouch identification are important steps in art restoration process. Since the main goal is to classify and understand the cause of damage, as well as to forecast its further enlargement, a proper tool for a precise detection of the damaged area is needed. However, the complex nature of the pattern is a reason why a simple, universal detection algorithm is not always possible to be implemented. Algorithms presented in this work apply mining structures which depend of expandable set of attributes forming a feature vector, and thus offer an elastic structure for analysis. The result obtained by our method in craquelure segmentation was improved comparing to the results achieved by mathematical morphology methods, which was confirmed by a qualitative analysis. Source

Del Hoyo-Melendez J.M.,Laboratory of Analysis and Non Destructive Investigation of Heritage Objects | wit P.,Polish Academy of Sciences | wit P.,Jagiellonian University | Matosz M.,Laboratory of Analysis and Non Destructive Investigation of Heritage Objects | And 4 more authors.
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms

X-ray fluorescence (XRF) analysis has become a standard method in archaeological science due to its non-invasive and non-destructive nature. This technique has extensively been used for the study of numismatic collections since the data derived from it can be correlated with manufacturing processes, provenance of raw materials, and geographical distribution of ancient mints. A group of 71 silver coins of the first Piasts: Boleslaus the Brave (996-1025) and Mieszko II Lambert (1025-1034) belonging to the collections of the National Museum in Krakow have been characterized using micro-XRF spectrometry. This is the most numerous collection of their coins representing nearly 30% of all known coins from these rulers. The research has focused on evaluating the use of this technique as a screening tool for elemental surface characterization of the alloys. Surveyed coins are mainly constituted by Ag, Cu and Pb along with trace levels of Fe, Ni, Zn, Au, Hg, Bi, and Br. Quantitative analyses have revealed Ag contents in the 81.6-97.5% range for all the evaluated coins. This study had the goal of providing information about the elemental composition of these objects, which will serve to enhance the existing knowledge about geographical and chronological diversification of Polish numismatic collections. © 2015 Elsevier B.V. All rights reserved. Source

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