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Palubicki B.,Arts et Metiers ParisTech | Palubicki B.,University of Life Sciences in Poznan | Marchal R.,Arts et Metiers ParisTech | Butaud J.-C.,Arts et Metiers ParisTech | And 4 more authors.
European Journal of Wood and Wood Products

In the present paper, a novel method for veneer checks measurement and description based on digital image analysis is evaluated. According to this method, the camera is located sideways to the veneer allowing for viewing the checks geometry in the cross-section of the veneer. Checks are opened by bending the veneer on a roller of a specific diameter and they are exposed in such a way that good visibility of checks is assured. The algorithm used reproduces the checks by finding their coarse positions on the rescaled image and then migrating to the original, full resolution image to precisely localize the checks' bottom. The method is automatic and delivers the most important information on checks of veneer, namely distances between checks and their depths. Source

Tamburini D.,University of Pisa | Lucejko J.J.,University of Pisa | Lucejko J.J.,National Research Council Italy | Zborowska M.,University of Life Sciences in Poznan | And 4 more authors.
Journal of Analytical and Applied Pyrolysis

Eight samples of ca. 3000 year old oak wood from the Biskupin site and a piece of sound oak (Quercus sp.) wood were analysed. The degradation state of archaeological oak wood was investigated using two analytical approaches: classical wet chemical analysis and analytical pyrolysis coupled with gas chromatography and mass spectrometry (Py-GC/MS) with in situ silylation. The results were compared with those obtained for sound oak wood. Chemical analysis provided information on the amount of wood components. Their alteration at a molecular level was investigated by Py-GC/MS, highlighting how degradation can affect the formation of primary and secondary wood pyrolysis products. The results showed that the chemical changes in the wood material in the eight samples examined had different entities and extents with comparison to sound oak wood. Samples taken from the external parts of the fragments had undergone a significant loss in polysaccharide components, whereas the internal parts were in a relatively good state of preservation. Evaluation of the relative amounts of pyrolysis products deriving from holocellulose and lignin highlighted that specific categories of compounds, such as lignin monomers and anhydrosugars, can be taken as an index for good preservation of wood components. These results will be used to evaluate the effectiveness of the in situ conservation strategy by repeating the analyses on these samples after some years and comparing the results. © 2015 Elsevier B.V. All rights reserved. Source

Walkiewicz F.,Poznan University of Technology | Materna K.,Poznan University of Technology | Kropacz A.,Institute of Wood Technology | Michalczyk A.,Institute of Industrial Organic Chemistry | And 3 more authors.
New Journal of Chemistry

A new group of quaternary ammonium ionic liquids with azolate (benzotriazolate, 1,2,4-triazolate, 4-nitroimidazolate, 2-methyl-4- nitroimidazolate) anions was prepared and characterized. The synthetic method employed was easy and quick, and required a polar solvent. The obtained ionic liquids were tested as anti-microbial and anti-fungal plant protection agents. Additionally, the surface-active properties and the phytotoxicity of the quaternary ammonium azolates were also studied. These clearly defined ionic liquids were found to be very effective anti-bacterial and anti-fungal agents. © 2010 The Royal Society of Chemistry and the Centre National de la Recherche Scientifique. Source

Zborowska M.,University of Life Sciences in Poznan | Stachowiak-Wencek A.,University of Life Sciences in Poznan | Waliszewska B.,University of Life Sciences in Poznan | Pradzynskl W.,Institute of Wood Technology
Cellulose Chemistry and Technology

The objective of the study was to characterize the U V light resistance of one of the exotic wood species -ipe (Tabebuia sp) - commonly used in the furniture industry, using the colorimetric and infrared spectroscopy analyses. A softwood species, Scots pine (Pinus sylvestris L.), was also studied for comparison purposes. Based on the results obtained after 100 h of light irradiation, colour changes were found in the samples of both analysed species, but the extentand pattern of the changes differed significantly. It was observed that the ipe wood was less influenced by light in comparison with the pine wood. The total colour difference of the pine wood amounted to 14.26 and for the ipe wood to merely 1.05. The most significant changes were observed in the case of chromatic coordinate "b". Based on the infrared spectroscopic analysis, it was concluded that 340 UV irradiation yields the degradation of lignin structure. The infrared spectra gave an insight into the changes occurring in the range of carbonyl groups present in the structure of wood components and confirmed the resistance of carbohydrates to UV irradiation. Source

Beyer M.,Institute of Wood Technology | Weichelt F.,Leibniz Institute of Surface Modification | Emmler R.,Institute of Wood Technology | Flyunt R.,Leibniz Institute of Surface Modification | And 3 more authors.
Macromolecular Materials and Engineering

Nanocomposite UV coatings with adjustable properties for use on wood substrates in outdoor conditions were developed. Nanoscale ZnO was shown to be an efficient light absorber. Coatings were characterized in terms of elongation at brake, residual PI and double bond conversion, universal hardness, transparency, hydrophobicity, and yellowing. Coated samples were artificially weathered and studied with regard to their optical and mechanical properties, as well as to changes in brightness, transparency, hydrophobicity, and water permeability. The prepared wood coatings showed an increased weather fastness and improved optical properties. The suitability for use in outdoor conditions was assured by optimizing the elasticity of the coating and decreasing its water permeability. © 2010 WILEY-VCH Verlag GmbH & Co. KGaA. Source

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