Your search resulted in 319 documents. Displaying 25 entries per page.
Non-stochiometric oxidation and ROS generation promoted by guaiacol lignin structures and lignocelluose surfaces may be a component of brown rot fungal degradation mechanisms
2019 - IRG/WP 19-10937
Model guaiacol compounds representing lignin monomers, as well as DHP-lignin and wood flour of controlled particle size were used to assess iron reduction at the pH of the natural wood cell wall. All compounds functioned as electron donors for ferric iron, with the lignin monomers demonstrating capacity for non-stochiometric reduction of iron with multiple moles of ferric ion reduced per mole of l...
Y Tamarua, M Yoshidaa, L D Eltisb, B Goodell
Hydroxyl accessibility - A brief review of deuterium exchange studies on modified wood
2019 - IRG/WP 19-20656
Wood modification imparts dimensional stability and decay resistance. The mechanism(s) by which this occurs are thought to be related to the bulking of the wood cell wall and subsequent moisture exclusion. Hence, quantification of accessible hydroxyl (OH) groups is of great interest when evaluating and increasing the understanding of the performance of modified wood. The aim of this study was to b...
G Beck, C Hill, G Alfredsen
Durability classification of preservative treated and modified wood
2019 - IRG/WP 19-20659
EN 350 (2016) allows formally to determine durability classes (DC) for wood products and wood-based materials, which was previously only possible for untreated wood in the form of natural durability. In a first study, the University of Goettingen carried out the durability classification of chemically modified (modified with 1,3-dimethylol-4,5-dihydroxyethyleneurea, DMDHEU) and preservative-treate...
S Bollmus, L Bachle, C Brischke, H Militz
Performance of modified wood in service - multi-sensor data fusion and its multi-way analysis
2019 - IRG/WP 19-20660
Recent developments in the field of electronic sensors and analytics provide new opportunity for accurate characterization of materials often based on portable and non-destructive methods. By using several complementary techniques, the material description is precise and complete. The data provided by multiple equipment, however, are often not directly comparable due to different resolution, sensi...
A Sandak, J Sandak, M Cocchi
Facile in-situ growth of Ag-TiO2 nanoparticles on polydopamine modified bamboo with excellent mildew-proofing
2019 - IRG/WP 19-30734
Bamboo with good mechanical properties, fast growth rate and low growth cost is one of very utilitarian structural material from forest resources only less important than wood. But it is especially easy to mildew during outdoor service resulting in appearance mould scattering and corrosion. In this work, a facile method was developed to increased mildew-proofinging capability of bamboo. Mussel-ins...
J Hu, Z Lu, G Liu, S Chang, Y Liu, X Li
Identification of Antifungal Compounds in Konjac Flying Powder and Assessment against Wood Decay Fungi
2019 - IRG/WP 19-30737
The antifungal activity of konjac (Amorphophallus rivieri) flying powder (a by-product produced during mechanical processing of konjac flour) ethanol extract was evaluated against wood decay fungi in culture. Compounds associated with antifungal activity in the extracts were isolated and purified by silica gel column chromatography. The antifungal active fractions were identified by ultra-high-per...
Z Bi, F Yang, Y Lei, J J Morrell, L Yan
Using X-ray scattering to elucidate the mechanisms behind the moisture and fungal decay resistance of epoxybutene modified wood
2019 - IRG/WP 19-40854
Chemical modification of the hydroxyl groups of wood can improve the properties of wood by providing moisture and biological resistance, as well as dimensional stability. Southern pine solid wood was chemically modified to various weight percentage gains (WPG) with epoxybutene (EpB, 8%-38% WPG). After modification, specimens were extracted with a toluene: ethanol (2:1) solution for 2 hours or wate...
R E Ibach, N Plaza
Dimensional stability and decay resistance of montmorillonite- furfuryl alcohol modified wood
2019 - IRG/WP 19-40856
Poplar (Populus cathayana) wood was impregnated successively by organo-montmorillonite (OMMT; in concentration of 2%) and furfuryl alcohol (FA, in concentrations of 15%, 30% and 50%) in a two-step method to prepare OMMT-FA modified wood. The modified wood samples were characterized using X-ray diffraction (XRD) and field emission scanning electron microscopy (FE-SEM). Moreover, wood physical and a...
L Zhang, J Cao
Study on the ability of wood-destroying fungi to grow through chemically modified wood
2019 - IRG/WP 19-40858
Over the last decades, chemical wood modification technologies were developed to increase the resistance against attack by wood-destroying organisms without using biocides. Most of those technologies are based on an impregnation step initially. In most treated wood products, mainly by using solid wood in thicker dimensions as in posts, poles, sleepers, deckings etc. it is known that wood impregnat...
L Emmerich, S Strohbusch, C Brischke, S Bollmus, H Militz
The anti-weathering mechanism of extractives in thermally modified Scots pine
2019 - IRG/WP 19-40880
Results from the electron spin-resonance spectroscopy (ESR) analysis indicated that thermally modification of wood can inhibit the generation of phenoxyl radicals during UV irradiation and consequently lead to the increase of the color stability of wood. In order to clarify the evolution and role of extractives in thermally modified wood during the process of weathering, the compositions of aceton...
H Shen, J Cao
Studying amount, location and state of water in modified wood at moisture levels relevant for fungal degradation
2020 - IRG/WP 20-40889
Water is an essential parameter for fungal degradation of wood, but degradation primarily occurs at high moisture levels at water potential in the range of -4 to -0.1 MPa, which corresponds to 97-99.9% relative humidity. At these moisture levels, water is present in the wood structure both in and outside of cell walls. The majority of previous studies on the interaction between wood and water for ...
M Fredriksson, E Engelund Thybring, Ramunas Digaitis
Elucidation of reactive sites of wood modified with acetic anhydride: Insights from density functional theory calculations
2020 - IRG/WP 20-40892
Density functional theory (DFT) was employed to investigate the interaction of cellulose and lignin with acetic anhydride for explaining the wood modification process. Atoms in molecules (AIM) and reduced density gradient (RDG) along with non-covalent interaction (NCI) plots were used to analyse the intermolecular bonding characteristics. Cellulose was modelled with a cellobiose unit (dimer of glu...
V Ponnuchamy, A Sandak, J Sandak, R Herrera Diaz
Extraction, identification and antifungal activity of polar extractives originated from various wood species
2020 - IRG/WP 20-20673
Extractives are non-cell wall small molecules present in wood and other lignocellulosic materials that can be removed by solvents. Although they represent a minor fraction in comparison with the structural cell wall components, they are an important source of functional groups or molecules with bioactivity or antioxidant properties, that could be used in medicine, cosmetic or wood preservation. T...
R Herrera, F Poohphajai, J Labidi, S Willför, A Sandak
Development of procedures for sampling, testing, and classification to determine the biological durability of wood and wood products
2020 - IRG/WP 20-20676
This paper informs about a research project, which deals with several shortcomings and a lack of clarity within EN 350:2016. The project started in January 2020, will run for 3 years, and is operated by the Institute of Wood Technology Dresden (IHD) and the University of Goettingen (UGOE).
Determination and classification of durability of wood and wood products against wood-destroying organisms ...
W Scheiding, K Jacobs, S Bollmus, C Brischke
The influence of chemical compounds on wood cell wall to surface cracks
2020 - IRG/WP 20-40908
Degradation due to cracking and dimensional changes caused by drying, have a significantly negative impact on the preservation and durability of wood. Therefore, the prevention of surface cracking, which tends to occur during the drying process, is vital. High temperature set drying is one of the most effective methods for preventing wood surface cracking. It begins with softening the wood at a hi...
R Suzuki, Y Mori, K Yoshihiro, K Yamashita, M Kiguchi
NewSiest-Enhancement of UV stability of thermally modified wood through envelope impregnation with nanobased stabilisers
2020 - IRG/WP 20-40909
Thermal modification is a process which improves the properties of wood, resulting in a material that can be disposed at the end of the product life cycle without presenting an environmental hazard. Thermally modified wood retains as a natural product and the grain, original colour variances and characteristics of wood are still present. However, exposure to daylight causes brightening or greying ...
K Srinivasa, M Petrič
Performance of resin-treated solid wood and laminated veneer lumber (LVL) under marine conditions
2021 - IRG/WP 21-10973
Wood is a traditional building material in the marine environment, where it is exposed to extremely harsh conditions. Most of the indigenous softwood and hardwood species in Europe are not durable against attack by marine organisms. Recently, wood modification has been considered as an alternative to protect non-durable wood species under use class (UC) 5 (EN 335, 2013) conditions. The present stu...
L Emmerich, C Brischke, S Bicke, H Militz
Experience Experience from over 20 years of field trials of resin treated wood – Marine borer resistance of MMF and DMDHEU modified wood
2021 - IRG/WP 21-10976
In 1999 a field test of Scots pine treated with MMF (Methylated Melamine Formaldehyde) resin and acetylated Scots pine post treated with MMF resin was started. Six years later a commissioned full NWPC test for BASF of Belmadur® (DMDHEU resin treated wood) was started at the same site.
The testing, according to European Standard EN 275, was done in a bay by Kristineberg Marine Research Station o...
M Westin, P Larsson Brelid, A O Rapp, J Habicht
Influence of weathering on surface roughness of thermally modified wood
2021 - IRG/WP 21-40915
Thermally modified wood is exposed to weathering similarly as other wood-based building materials. It has been reported that if thermally modified wood is exposed to weathering, its moisture performance might decrease fairly fast. The aim of this study was to determine whether this phenomenon is associated with crack formations or roughness. Norway spruce, thermally modified spruce, wax-treated th...
E Kerzic, B Lesar, M Humar
Effect of MVOC exposure on mycelial growth of wood rotting fungi
2021 - IRG/WP 21-10977
It is well known that wood rotting fungi produce microbial volatile organic compounds (MVOCs) as metabolites. In our previous studies, we have found that some MVOCs produced by wood rotting fungi are common to fungal species tested in the studies, while others are specific to each species. Furthermore, it has been also shown that each wood rotting fungi do not always produce the same type of MVOCs...
S Horikawa, R Konuma, M Yoshida
Evaluation of decay and energy properties from thermally modified biomasses during fungal deterioration by NIR-spectrometry
2021 - IRG/WP 21-40922
This study is focused on the prediction of fungal weight loss (WL) and high heating value (HHV) from raw and torrefied waste lignocellulosic feedstocks, according to their exposure duration to wood-destroying fungi, using near infrared spectroscopy (NIR) and chemometrics models.
Sugarcane bagasse, coffee husk, eucalyptus and pine shavings were torrefied at 290 °C in a screw reactor, during 5, 7...
B de Freitas Homem de Faria, P Santana Barbosa, J Valente Roque, A de Cassia Oliveira Carneiro, P Rousset, K Candelier, R F Teofilo
Impregnation of wood with antifungal compounds from low-quality tree biomass
2022 - IRG/WP 22-30763
In this paper we have reviewed recent research on the development of bio-based preservative formulations for wood done at the Department of wood science and technology, Ljubljana. Preservative formulations used in this investigation were prepared using plant polyphenols as biocidal agents. These nonstructural components of wood were stilbenes and flavonoids, and were extracted from wood of broken ...
V Vek, I Poljanšek, A Balzano, M Humar, P Oven
Service trial of different materials exposed in jetties at Öresund. Progress report No. 5
2022 - IRG/WP 22-30764
This report contains results of the fifth inspection on the performance of different decking materials – preservative-treated wood, modified wood, natural durable wood, re-cycled plastics and wood-plastic composites (WPCs) - available on the market and exposed since 2013 (some since 2014 and 2016) by the City of Malmö in two jetties near the Øresund Bridge, south of central Malmö in Sweden. T...
J Jermer
Durability against fungal decay of sorbitol and citric acid (SorCA) modified wood
2022 - IRG/WP 22-40928
Most European-grown wood species are susceptible to biological degradation, specifically, they suffer from a poor resistance against wood-destroying fungi. Therefore, prior to outdoor exposure, wood has to be treated either by applying a protective coating on its surface or by full-volume impregnation with antifungal chemicals. However, due to environmental and health concerns, the most frequently...
K Kurkowiak, L Emmerich, H Militz
Optimized composition of alkyd emulsion with nanoparticles of iron oxide for enhancing protection of thermally modified wood
2022 - IRG/WP 22-40940
Thermal treatment is acknowledged as an environmentally friendly method to improve durability of wood and some of its properties, such as biological resistance, dimensional stability, reduced hygroscopy. Despite these improvements, when used outdoors, also thermally treated wood is subjected to the action of environmental factors, like solar radiation, moisture, precipitations, temperature, etc., ...
E Sansonetti, D Cīrule, I Andersone, B Andersons, E Kuka