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Fazinic S.,Ruder Boskovic Institute | Bozicevic Mihalic I.,Ruder Boskovic Institute | Tadic T.,Ruder Boskovic Institute | Cosic D.,Ruder Boskovic Institute | And 2 more authors.
Nuclear Instruments and Methods in Physics Research, Section B: Beam Interactions with Materials and Atoms | Year: 2015

We have developed a small wavelength dispersive X-ray spectrometer to explore the possibility of performing chemical speciation on microscopic samples utilizing focused ion beams available at the Rudjer Boskovic Institute ion microprobe. Although PIXE spectra are in principle chemically invariant, small influence of chemical effects could be observed even with Si(Li) or SDD detectors. Such chemical effects can be clearly seen with high resolution crystal X-ray spectrometers having energy resolution of several eV. A dedicated vacuum chamber, housing the diffraction crystal, sample holder and CCD X-ray detector, was constructed and positioned behind the main ion microprobe vacuum chamber. Here we will briefly describe the spectrometer, and illustrate its capabilities on measured K X-ray spectra of selected sulfur compounds. We will also demonstrate its abilities to resolve K and M X-ray lines irresolvable by solid state ED detectors usually used in PIXE. © 2015 Elsevier B.V. All rights reserved.

Kovacevic S.,University of Zagreb | Car G.,Croatian Conservation Institute
Fibres and Textiles in Eastern Europe | Year: 2014

The first part of the paper presents the historical development of looms and analyses the oldest preserved fabric samples. Emphasis is given to the analysis of woolen fabrics recently found in Bosnia and Herzegovina in the regions inhabited by Croats. The results show that the fabric is aged from 3550 to 3800 years and is the oldest woolen fabric in Europe. The characteristic of these fabrics is their specific weaving with selvedges on all four edges of the fabric.The fabric was woven from a course wool yarn of various densities in the weft direction using different weaves and weaving techniques, with a border created by weft thread at the beginning and end of weaving. This is the reason why the fabric looks embossed and compact and is easily recognisable amongst the old hand weaving in these regions.

Novak M.,Croatian Academy of science and Arts | Plese T.,Croatian Conservation Institute | Cavka M.,University of Zagreb
AMHA - Acta Medico-Historica Adriatica | Year: 2013

This paper presents a case of skull trepanation from the town of Ludbreg in north-western Croatia. This is the second case of trepanation reported in human skeletal remains from archaeological sites in Croatia. The procedure was performed on an adult male buried in a tomb under tegulae at the "Somod{stroke}i Garden" site. The archaeological context and radiocarbon analysis date the bone sample to the 5th century AD, i.e. to the Migration Period. The trepanned aperture is located on the left side of the frontal bone and the left parietal bone. The lesion is oval in shape with all three layers of the calvarium breached, leaving dura mater exposed. This neurosurgical intervention was most probably performed by scraping for therapeutic reasons (head injury). The morphology of the lesion strongly indicates that the individual survived the operation and lived for a longer period of time, several years at least.

Vanmeert F.,University of Antwerp | Mudronja D.,Croatian Conservation Institute | Fazinic S.,Ruder Boskovic Institute | Janssens K.,University of Antwerp | Tibljas D.,University of Zagreb
X-Ray Spectrometry | Year: 2013

A current method for the protection of cretaceous limestone present in various monuments consists of performing a passivating treatment with ammonium oxalate (AmOx). A calcium oxalate protective layer is formed on the surface and enhances the acid resistance of the stone. The in-depth formation of the calcium oxalate layer was investigated on cross sections by using combined micro X-ray fluorescence and micro X-ray powder diffraction (μXRF/μXRPD). XRPD showed the presence of both whewellite and weddellite in the calcite stone matrix. A correction was made for sample misalignment, which was visible in both the fluorescence and the diffraction line measurements. A semi-quantitative analysis was performed on the basis of Klug's equation for a two-phase mixture (the presence of weddellite was neglected) without the need for a known reference sample. By assuming two extreme compositions for a reference weight fraction (1 and 99wt%), it was possible to obtain whewellite concentration profiles, which can be used for comparing the effectiveness of different methods for the application of AmOx to the stone surface and the effect of treatment time and AmOx concentration used. It is shown that for the relative amounts of whewellite formed, the differences due to the assumed weight fractions are smaller than the errors due to sample heterogeneity and preferred orientation. © 2013 John Wiley & Sons, Ltd.

Mudronja D.,Croatian Conservation Institute | Vanmeert F.,University of Antwerp | Hellemans K.,University of Antwerp | Fazinic S.,Ruder Boskovic Institute | And 4 more authors.
Applied Physics A: Materials Science and Processing | Year: 2013

Samples of cretaceous limestone have been treated with three application methods (poultice, immersion and brushing) using different concentrations of ammonium oxalate solution (AmOx) and varying treatment time in order to test the efficiency of surface and in-depth formation of a protective layer of calcium oxalate (CaOx). Synchrotron-based microanalytical techniques (SR-μXRD with 12.5 μm×7.5 μm (H×V) probe size, SR-μFTIR with 10 μm×10 μm and 8 μm×20 μm probe sizes) and laboratory μFTIR, XRD and SEM have been employed for analysis of the treated samples. Synchrotron-based techniques showed variations in the CaOx distribution along the surface on a micrometer scale. All treatments resulted in the development of a CaOx layer with a maximum thickness of approximately 40 μm. Application by the brushing method with 10 1-min applications with 5-min breaks during one hour showed a development of the calcium oxalate layer equivalent to the poultice treatment taking 10 h. This treatment could be preferred for large marble or limestone surfaces where poultice usage is economically not feasible. © 2012 Springer-Verlag Berlin Heidelberg.

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