Your search resulted in 180 documents. Displaying 25 entries per page.
Decrease of the antidecay resistance of beech wood treated with organotin fungicides after its natural ageing
1998 - IRG/WP 98-30185
The antidecay resistance of beech-wood samples (120 x 8.5 x 8.5 (MM)) treated with tributyltin fungicides gradually decreased due to prolongation of their natural ageing:
tributyltin fungicides (TBTO, TBTS, TBTCA, TBT-DEDTK were applied by pressure impregnation technique in ethanole solutions (c = 0. 1%, 0.33% or 1%);
treated beech-wood samples were naturally aged without their contact with grou...
L Reinprecht
The use of modulus of rupture and modulus of elasticity in natural durability testing
1997 - IRG/WP 97-20117
Losses in weight, losses in bending strength and changes in elastic behaviour were assessed in a fungus cellar test with beech wood stakes (Fagus sylvatica). Results were gained after 8, 12, 16 and 20 weeks resp . The outcomes show, that the non-durable species beech is very rapidly attacked by fungi and loses up to 60% of its initial bending strength even within the first 8 weeks. Earlier researc...
L Machek, H Militz, W Gard
Soft rot decay in acetylated wood. Chemical and anatomical changes in decayed wood
2002 - IRG/WP 02-40231
Acetylated Beech (Fagus sylvatica) and Scots Pine (Pinus sylvestris) wood were studied in soil beds under laboratory conditions for longer periods. High mass losses and dynamic MOE losses were measured in non-acetylated wood and at lower weight percent gains (WPG). Rapid losses of lignin, holocellulose and ?-cellulose occurred in non-acetylated beech wood and no losses were detected at the highest...
B Mohebby, H Militz
Effect of cyclic change of temperature on fungal growth and mass loss
1994 - IRG/WP 94-10065
For estimating the effect of cycling change of temparature on fungal growth, four Japanese species, sugi (Cryptomeria japonica), hinoki (Chamaecyparis obtusa), akamatsu (Pinus densiflora) and buna (Fagus crenata), four fungal species, Tyromyces palustris, Gloeophyllum trabeum, Coriolus versicolor, Pycnoporus coccineus, and five temperature conditions, 10, 20, 27, 35°C and cyclic temperature (20°...
K Suzuki, K Okada
Assessment of wood decay in small-scale unsterile soil-bed tests
1997 - IRG/WP 97-20111
This study is concerned with the investigation of wood decay in small-scale unsterile soil-bed tests. Tests were performed with untreated heartwood samples from five hardwood species of different natural durability classes ranging from highly perishable to very resistant. Our results confirmed the critical role of soil moisture content on wood decay. The highest decay rates were observed at moistu...
L Machek, A M Derksen, R Sierra-Alvarez
Evaluation of wood durability by laboratory test - A new equation to predict wood durability
2001 - IRG/WP 01-20230
To estimate the wood durability in a short term, periodical weight determination was carried out in a laboratory test. This test provided the results comparable to those of the field test and the fungus cellar test, but it required much more jobs in comparison to the usual accelerated laboratory test. To save the time and jobbing for this method, a new equation was devised from simple two assumpti...
I Momohara, K Yamamoto
Laboratory testing of wood natural durability - In soil-bed assays
1998 - IRG/WP 98-20141
Laboratory methods for assessing wood decay resistance are being investigated in the framework of an ongoing European research project. This paper summarizes the main results obtained for soil-bed tests based on the European prestandard ENV 807-Test 2. The data suggest that this testing methodology is suitable for evaluating the natural durability of timber species in soil-contact under conditions...
R Sierra-Alvarez, I Le Bayon, J K Carey, I Stephan, J Van Acker, M Grinda, G Kleist, H Militz, R-D Peek
A dynamic approach to assess the modulus of elasticity in wood decay testing
1998 - IRG/WP 98-20139
In this study, the changes in elastic behaviour and mass losses of different hardwood and softwood species exposed to decay in a laboratory soil tests were assessed. Wood decay was monitored using different assessment methods, namely: mass loss and changes in elastic behaviours (MOE) determination. Elastic changes were determined by static and dynamic methods, for the latter, acoustic technique wa...
L Machek, H Militz, R Sierra-Alvarez
Measuring Soil Respiration as a New Approach to Describe the Interaction Between Wood (Treated and Untreated) and Microbiologically Active Soil
2006 - IRG/WP 06-20344
Soil respirometry was employed to examine the relationship between both the performance of copper organic preservatives in contact with and the amount of carbon dioxide evolved from soil and the effect of wood treated with preservatives on carbon turnover in soil. Wood was treated with a range of copper organic preservatives intended for use in ground contact as well as an organic preservative in...
I Stephan, W Mierke
Effect of fumigation with Sulfuryl Difluoride on wood inhabiting fungi, a laboratory test
2006 - IRG/WP 06-30410
Special methods are necessary for the control of wood destroying organisms in the preservation of monuments and historic buildings because of the conservation of their originality and uniqueness.
The control of wood destroying organisms can be realized with conventional liquid wood preservatives or alternative methods. One of these methods is the fumigation. One fumigant, which was in the past of...
A Pfeffer, W Unger, G Fröba, G Binker
Influence of ring width and wood density on durability of oak heartwood
2008 - IRG/WP 08-10639
Oak (Quercus sp.) is considered as one of the most durable European wood species. The most important factor influencing oak durability was extractive content. In our work, we were interested in if oak-wood durability is affected by ring-width and related density. Therefore, oak heartwood specimens made of boards with different ring widths were exposed to five different fungal species Daedelea quer...
M Humar, P Oven, F Pohleven
Treatment of Selected Lesser Used Timber Species against Subterranean Termites using Heartwood Extracts from Teak (Tectona grandis) and Dahoma (Piptadeniastrum africanum)
2008 - IRG/WP 08-30476
Lesser used timber species represent a valuable material for all-purpose uses. However, most of them are not durable. They are, for effective utilization, often treated with all manner of toxic synthetic substances to enhance their natural durability, especially in the tropics where conditions favour their deterioration. Most of these toxic synthetic substances often pose a threat to the environme...
A Asamoah, C Antwi-Boasiako, K Frimpong-Mensah
High Temperature Treated Wood
2008 - IRG/WP 08-40429
High temperature can modify internal structure and physic-chemical properties of wood by a controlled pyrolysis process. Such treatment, among other changes in properties, modifies the wood color in a way that resembles exotic species, increasing its market value. The main objective of this work is to determine the changes in wood properties caused by the effect of temperature and time, in order t...
C C Borges, A L Barbosa, R Faber de Campos, S T Targas
Testing of decay resistance of sapwood and heartwood of thermally modified Scots pine and Norway spruce
2010 - IRG/WP 10-40523
Thermal modification at elevated temperatures changes the chemical, biological and physical properties of wood. One of the main targets of thermal modification is to increase the biological durability and decay resistance of wood. Although the effects of thermal modification on wood have been widely studied, the significance of sapwood and heartwood on the resistance of thermally modified wood has...
H Viitanen, S Metsä-Kortelainen
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
Effects of nano-silver on brittleness of heat-treated solid woods
2011 - IRG/WP 11-40572
The present study is aimed at the effect of heat-treatment of normal as well as nano-silver-impregnated Populus nigra, Populus deltoides, and Fagus orientalis on brittleness. Specimens were impregnated with 200 ppm water-based solution of nano-silver particles under 3 bars in a pressure vessel using empty-cell process. For heat treatment, both nano-silver-impregnated and normal specimens were kept...
H Reza Taghiyari, B Moradi Malek, A Karimi
Laboratory and Field evaluation on Natural Resistance and Feeding Preference of Different Wood Species to Subterranean Termites (Isoptera: Rhinotermitidae, Termitidae) in Pakistan
2012 - IRG/WP 12-10769
The resistance of twenty four different woods to attack and damage by subterranean termite species Heterotermes indicola (Wasmann) and Coptotermes heimi (Wasmann) was evaluated by choice and no choic in laboratory and field trials. Mean wood mass loss was calculated for both laboratory and field trials results using Analysis of Variance (ANOVA). Mean percentage termite mortality was calculated fo...
S A Malik; F Manzoor, B M Ahmed (Shiday)
Variation in two Postia placenta strains, MAD-698-R and FPRL 280 – mass loss, DNA content and gene
2012 - IRG/WP 12-10781
Brown-rot fungi such as Postia placenta are common inhabitants of forest ecosystems and brown rot fungi are also largely responsible for the destructive decay of wooden structures. The aim of this study was to compare two commonly used strains of Postia placenta – MAD-698-R and FPRL 280. Scots pine sapwood samples were exposed for two and eight weeks to both fungal strains. The following was inv...
N Thaler, G Alfredsen, C G Fossdal
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
Development of a quality control assessment method to predict properties of heat treated wood
2012 - IRG/WP 12-40611
Heat treatment has been used to improve properties of non durable European species. Chemical modification of some of the wood components provides improved dimensional stability and biological performance against decay fungi while mechanical properties such as modulus of rupture are reduced. Quality control of commercially made thermally treated wood is one of the major challenges to allow its indu...
M Chaouch, K Candelier, S Dumarcay, A Pétrissans, M Pétrissans, P Gérardin
Effect of Nano and Micronized Particles as Wood Preservatives for Termite Control
2013 - IRG/WP 13-30620
Subterranean termites are a major factor in the biodegradation of wood constructor products. In this study the efficacy of wood treated with micronized copper, zinc oxide and their mixture was compared to that of wood treated with soluble amine copper oxide with subterranean termites in a laboratory test. All of the formulations tested were effective in controlling wood degradation by the termites...
M Akhtari, D Nicholas, A Rowlen, M Arefkhani
Application of a model for the prediction of fungal degradation of thermally modified beech timber by Trametes versicolor
2013 - IRG/WP 13-40622
Colour measurement technology is found to be feasible for characterization of the property changes of thermally modified timber (TMT). In opposite to time-consuming and expensive laboratory tests a non-destructive test represents an improvement for the manufacturer of TMT. Therefore the aim of this study was to develop a method which allows sorting the different treatment intensities after the man...
Clauder, L., Richter S., Unger, W., Pfriem, A
Utilization of TG-DSC to study thermal degradation of beech and silver fir
2013 - IRG/WP 13-40628
Thermal treatment of wood is, besides other wood modification system, used to improve the decay resistance and dimensional stability. However, the chemical changes that are caused by treatment process are still difficult to quantify, characterize and control. Previous studies have shown that thermodesorption coupled to GC-MS is an attractive tool to characterize and quantify products formed during...
K Candelier, A Treu, J Dibdiakova, E Larnøy, A Petrissans, S Dumarçay, M Pétrissans, P Gérardin
Effect of Nano and Micronized Particles as Wood Preservatives for Termite Control
2013 - IRG/WP 13-30620
Subterranean termites are a major factor in the biodegradation of wood constructor products.
In this study the efficacy of wood treated with micronized copper, zinc oxide and their
mixture was compared to that of wood treated with soluble amine copper oxide with
subterranean termites in a laboratory test. All of the formulations tested were effective in
controlling wood degradation by the term...
M Akhtari, D Nicholas, A Rowlen, M Arefkhani
Experiences with an industrial system for controlled thermal wood modification in pressurized unsaturated steam
2014 - IRG/WP 14-40678
Thermal wood modification in pressurized reactors has a long history, but these processes are to date industrially scarcely used, because of the relatively complicated process equipment, compared to the more common high-temperature processes in kilns at atmospheric pressure. However, based on our practical experience with the FirmoLin® process, supported by recent scientific findings, it is foun...
W Willems