Your search resulted in 91 documents. Displaying 25 entries per page.
Time-of-Flight Secondary Ion Mass Spectrometry Analysis of Polyethylene Glycol Penetration into Wood Cell Walls
2006 - IRG/WP 06-20328
Penetration of high molecular weight polyethylene glycol (PEG) into wood cell walls was investigated in red pine. PEG of different molecular weights (1000, 8000 and 20000) was labelled by bromination and treated samples were analyzed on Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) in dynamic mode. Both negative and positive spectra of the samples were collected in high spatial (bunche...
D Jeremic, P Cooper, P Brodersen
A step towards a better understanding of fungal colonization of modified wood - QRT-PCR studies
2008 - IRG/WP 08-10653
The area of wood protection is in a period of change. New wood protection systems have been developed while their mode of action remains insufficiently understood. The development of molecular methods provides potential tools to investigate the interaction between modified wood and decay fungi. One small step to tackle some of the unsolved questions about the mode of action of modified wood is tak...
G Alfredsen, A Pilgård, A Hietala
Durability and fungal colonisation patterns in wood samples after six years in soil contact evaluated with qPCR, microscopy, TGA, chitin- and ergosterol assays
2009 - IRG/WP 09-20402
There is a need to establish new objective and sensitive methods for early detection and quantification of decay fungi in wood materials. Molecular methods have proven to be a useful tool within wood protection issues, however, this field is still poorly explored and so far relatively few have used these methods within the field of wood deterioration. Among the techniques used in the indirect quan...
A Pilgård, G Alfredsen, I Børja, C Björdal
Postia placenta gene expression during growth in furfurylated wood
2010 - IRG/WP 10-10734
Modified wood can provide protection against a range of wood deteriorating organisms. But we still lack information about why the modified wood is protected from microbial attack. Several hypotheses have been put forward for the mode of action against wood decaying fungi, including inhibition of action of specific enzymes, but they still need further testing. In this study gene expression of the b...
G Alfredsen, C G Fossdal
Determination of a fixation time of wood preservatives: A discussion paper
2010 - IRG/WP 10-20436
The intention of that paper is to initiate a discussion on the basis of a French method in combination with a German approach regarding the need of a method for the determination of a fixation time and especially to obtain input as well as ideas concerning a possible test design. Since no harmonised European approach exists up to now concerning the determination of a fixation time, CEN TC 38 (2009...
E Raphalen, E Melcher
Service life prediction of wooden components – Part 1: Determination of dose-response functions for above ground decay
2010 - IRG/WP 10-20439
Scots pine sapwood (Pinus sylvestris L.) and Douglas fir heartwood (Pseudotsuga menziesii Franco) specimens were exposed in double layer field trials at 24 different European test sites under different exposure conditions (in total 28 test sets). The material climate in terms of wood moisture content (MC) and wood temperature was automatically recorded over a period of up to eight years and compar...
C Brischke, A O Rapp
Direct estimation of the durability of high-pressure steam modified wood by ESR-spectroscopy
2010 - IRG/WP 10-40508
Heat generated persistent free radicals have been detected by electron spin resonance measurement of thermally modified wood, prepared by high pressure superheated steam treatment. The specific density of these radicals have been correlated with the durability against basidiomycetes, as measured by the European standard EN113 test. In the lower range of specific radical densities, the found correl...
W Willems, A Tausch, H Militz
Basidiomycete colonization of Scots pine sapwood quantified by qPCR and TGA
2011 - IRG/WP 11-10750
Scots pine (Pinus sylvestris L.) is an important softwood species in Northern Europe and is frequently used as material for various wood protection systems. In Europe, EN 113 is the standard basidiomycete laboratory durability test method, using mass loss as evaluation criteria. In this paper quantitative real-time PCR (qPCR) and thermogravimetric analysis (TGA) was used to characterize coloniza...
G Alfredsen, S Bollmus, T K Bader, K Hofstetter
The effects of acetylation level on the growth of Postia placenta
2011 - IRG/WP 11-10751
To understand the defence mechanisms utilized by decay fungi when exposed to different wood protection systems the study of gene expression can give us some answers. When the DNA sequences are known, primers can be designed to detect transcripts of genes with gene products related to basic cellular processes and hyphal growth. The characteristic gene products induced in different fungi by differen...
A Pilgård, G Alfredsen, C G Fossdal, C J Long II
Quantification of four dark colored mould fungi by real time PCR
2011 - IRG/WP 11-10754
Coated wooden claddings in building facades are widely used in the Scandinavian countries, and are often preferred to other materials. Wood is facing increasing competition from other materials that are less labor intensive at the construction site and materials with less demand for maintenance thru service life, and makes further development of wooden claddings essential. Growth of discoloring mo...
E Larnøy, L Ross Gobakken, A M Hietala
Methods of field data evaluation - time versus reliability
2011 - IRG/WP 11-20466
Field testing of wood and wood-based products is so far the most reliable way to get information on performance with respect to durability and expected service life. However, field trials are extremely time and cost consuming. The main objective of the present study was to investigate possible correlations between early stages of decay, preferably during the first 5 years, and the actual service l...
P Larsson Brelid, C Brischke, A O Rapp, M Hansson, M Westin, J Jermer, A Pilgård
Non-destructive evaluation of wood decay
2011 - IRG/WP 11-20479
Evaluation of wood decay is often prone to subjective assessment. Standard rating scales are based on human perception of decay, often in addition to weight loss measurements. Especially the assessment of graveyard specimens or other long term testing material that has to be monitored regularly on a non-destructive basis, is challenging. In this paper two techniques are presented that can deliver ...
J Van den Bulcke, I De Windt, N Defoirdt, J Van Acker
Effects of Nano-Wollastonite on Ignition Time Reduction in MDF
2012 - IRG/WP 12-40576
Effects of wollastonite nano-fibers on ignition time reduction in medium density fiberboard were studied. Nanowollastonite was applied at 5, 10, 15, and 20 g/kg dry weight basis of wood fibers and compared with control specimens. Two application methods of nanowollastonite were used: surface application, and internal application. Specimens of 150×130×9 mm were prepared and the ignition times wer...
H Reza Taghiyari, H Rangavar, P Noori, A Karimi
The effect of press time on springback and water absorption of acetylated particleboard
2012 - IRG/WP 12-40579
In this study the effect of press time on springback, thickness swelling and water absorption was investigated. After 24 hours soaking in acetic anhydride, in order to achieving WPG 17%, acetylated particles were heated in an oven at 120 0C for 360 minutes. Acetylated and nonacetylated (control) particleboards were produced with 10% melamine urea formaldehyde (based on the oven-dry weight of part...
F Bavaneghi, M Ghorbani, A Kargarfard
The effects of acetylation level on the growth of Postia placenta over 36 weeks
2012 - IRG/WP 12-40589
Genomic sequencing gives us a tool to systematically and rapidly discover novel genes, how their products function in the cell, and explore their interactions. When the DNA sequences are known, primers can be designed to detect transcripts of genes with gene products related to basic cellular processes and hyphal growth. The characteristic gene products induced in different fungi by different wood...
A Pilgård, G Alfredsen, C G Fossdal, C J Long II
Tar-oil uptake vs time in immersion treatment of short pine posts: A simple technique applicable to rural communities of Papua New Guinea
2012 - IRG/WP 12-40608
Pinus caribaea and Araucaria cunninghamii logs ca. 100 mm in diameter were shortened to lengths 25-30 cm, conditioned to at/below fibre saturation point (FSP) for immersion/dip treatment using a hot- and- cold bath open- tank process. Before oven-drying and subsequent treatment, individual test specimens were numbered, their green weights and volumes, and dry weights recorded for basic density, vo...
B K Gusamo, R Tulo
Communities of mold fungi on flooded building materials
2013 - IRG/WP 13-10799
A small building built to residential code was flooded using farmland pond water to a depth of two feet at Tuskegee University. The building was drained and left enclosed for an additional three weeks. A total of 168 material samples were removed either immediately after opening (wet) or seven months after flooding (dry). Wall materials sampled included fiberglass batt insulation, gypsum wallboard...
F Skrobot III, H Aglan, S V Diehl
Statistical analysis of durability tests - Part 2: Principles of time-to-failure and application on field test data
2013 - IRG/WP 13-20512
Service life prediction is an important topic in wood research, especially with regard to the Construction Products Regulation (CPR). Both laboratory tests as well as in-service performance testing is therefore essential, in combination with proper monitoring and analysis tools. A crucial concept is variability and the incorporation of variability in tests and analysis. In this paper we focus on t...
J Van den Bulcke, I De Windt, C Brischke, C R Welzbacher, A O Rapp, J Van Acker
Extraction and analysis of DNA from green and seasoned timber as basic methods for determination of wood species and origin
2013 - IRG/WP 13-20523
Against the background of the European timber trade regulation EUTR, commenced to law by March 2013, the determination of wood species and tracing of its origin is getting a great importance. A promising approach for establishing fast and reliable tracking systems for wood products is DNA analysis. A critical point is the extraction of analysable DNA from the wood and its lignified cell walls. Thu...
K Jacobs, H Mende, W Scheiding
Postia placenta cellulase gene expression in modified wood during incipient decay
2013 - IRG/WP 13-40626
In optimization of modified wood, it is important to understand the mode of action of the wood modification and how the fungi response to it. The aim of this study was to investigate the expression of cellulases during the first two weeks of Postia placenta exposure in acetylated, DMDHEU-treated and thermally modified as well as in untreated wood. Using real-time PCR, the gene expression patterns ...
R Ringman, A Pilgård, K Richter
Performance standards for wood in construction – delivering customer service life requirements
2013 - IRG/WP 13-20537
There is increasing need for consideration of performance classification for wood products in construction, as evidenced by the CPR, warranty providers and end user demands for information. This means we need to radically consider how the tests we conduct on wood for durability (especially biological durability) can inform on service life and how they might if possible be translated into a perform...
E Suttie, C Brischke, F Englund, E Heisel, J Jermer, D Lorenzo, M Polášek, S Thelandersson, J Van Acker
Moisture dynamics of wood and wood-based products – Results from an inter-laboratory test
2014 - IRG/WP 14-20539
In the frame of the European research project PerformWOOD in close liaison with the CEN task group TG EN 350 of CEN TC 38 WG 21 in total six research institutes teamed up and initiated an inter-lab trial (Round Robin) to investigate the suitability of different test methods to determine the wetting ability of wood. The moisture performance of wood and wood-based products has been recognized as key...
C Brischke, L Meyer, C Hesse, J Van Acker, I De Windt, J Van den Bulcke, E Conti, M Humar, H Viitanen, M Kutnik, L Malassenet
A screening of factors that might influence the result of laboratory decay tests
2014 - IRG/WP 14-20548
Laboratory fungal decay tests provide important tools for performance testing of wood materials. But they are also hampered with some uncertainties regarding reproducibility. In addition to variation between fungal species and strains the test conditions are also believed to have some influence. The aim of this study was to screen the effect of a selection of test parameters that might influence t...
E Larnøy, G Alfredsen, A Treu, S Kolstad
Critical parameters on moisture dynamics in relation to time of wetness as factor in service life prediction
2014 - IRG/WP 14-20555
The concept of natural durability or enhanced durability based on the presence of active ingredients having an impact on both fungi and insects is not the only parameter steering the material resistance. Complementary resistance to getting wet (wetting ability) and consequently the ease of drying afterwards will lead to a parameter related to the time a piece of wood will remain under such wet con...
J Van Acker, I De Windt, W Li, J Van den Bulcke
The combined effect of wetting ability and durability on field performance – verification of a new prediction approach
2015 - IRG/WP 15-20565
Comprehensive approaches to predict performance of wood products are requested by international standards and the first attempts have been made in the frame of European research projects. However, there is still an immanent need for a methodology to implement the durability and moisture performance of wood in a performance classification system. The aim of this study was therefore to establish an ...
C Brischke, G Alfredsen, P-O Flæte, M Humar, T Isaksson, L Meyer