Your search resulted in 90 documents. Displaying 25 entries per page.
Mechanistic aspects of the reactions of copper complexes with lignin in the presence of hydrogen peroxide and lipid hydroperoxide model compounds as proposed for white rot fungi
2001 - IRG/WP 01-10399
The structural principles and the oxidative reactions of the catalytic system consisting of copper, hydroperoxides, and copper coordination compounds that contain aromatic nitrogen atoms are similar to those of catalytic centers of oxidative enzymes involved in delignification reactions of white rot fungi. The system is capable of selectively degrading lignin and its low molecular weight would all...
K Fackler, P Lamaipis, E Srebotnik, M Humar, C Tavzes, F Pohleven, M Sentjurc, T Watanabe, K Messner
Extracellular hydrogen peroxide-producing and one-electron oxidation system of brown-rot fungi
1990 - IRG/WP 1445
Wood-component-degrading compounds involved in the initial degradation of the cellulose and lignin in wood were isolated from wood-containing culture of brown-rot fungi, Gloeophyllum trabeum and Tyromyces palustris and partially purified by gel filtration on Sephadex G-25 and DEAE-Sepharose ion-exchange chromatography. The compounds were glycoproteins. The molecular weights of the glycoproteins as...
A Enoki, S Yoshioka, H Tanaka, G Fuse
Determination of the amine to copper ratio remaining in wood after leaching
2002 - IRG/WP 02-30285
The effectiveness of the protection and the environmental impact of the treated wood are two of the most important aspects that need to be understood for all preservatives. Both are particularly influenced by the loss of biocidal components from treated wood. For amine copper preservatives, copper fixation determines the leaching resistance of the copper and amine compounds formed in wood. Previou...
N Lucas, J N R Ruddick
Experiments on the degradation of tributyltin oxide: A progress report
1984 - IRG/WP 3287
A variety of experiments designed to assess the chemical and physical factors affecting the degradation of tributyltin oxide in treated timber are described. Simple procedures in which temperature and oxygen availability were increased in the presence of wood and water suggest that the wood itself was of prime importance. Attempts to decrease degradation with antioxidants were unsuccessful but led...
R J Orsler, G E Holland
Simulation test of subchronic inhalation toxicity of TBTO vapours in the air
1987 - IRG/WP 3454
The test was carried out in a wainscotted room of a normal size. Wooden panelling had been treated with one coat of basic preserving agent and, after the installation, with 2 coats of stain. Laboratory animals (rats) were kept in this room for 90 days. For the same period a control group of test animals was kept in a room of equal size where there was no panelling. During the test, concentration o...
V Skubic, S Kobal, J Stupar, R Ajlec, J Korošin, G R Pecenko
Mould growth at lumber surfaces of pine after kiln and air drying
1994 - IRG/WP 94-40033
Distribution of water soluble substances in green wood and later redistribution during drying is of importance for the colonisation of wood by microorganisms. According to literature the availability of nitrogenous materials is probably a major limiting factor to the microbial colonisation of wood. King et al. (1974) and Oxley et al. (1976) have shown correlation between surface nutrient concentra...
N Terziev, J Bjurman, J B Boutelje
In-house accelerated method for testing decay resistance of treated wood
2004 - IRG/WP 04-20286
Fungicidal compounds often change their effectiveness when they are incorporated into candidate formulations. For this reason fungistatic effectiveness needs to be re-evaluated as many times as the formula has been modified for better performance. To avoid multiple expenses, in-house fungistatic tests are essential. Our goal was to develop in-house usable, simple but reliable and reproductive proc...
N Vidovic
Some practical implications from recent research on the fixation of CCA preservatives
1975 - IRG/WP 358
The mechanism of fixation of CCA preservatives is briefly described. If the temperature is increased during the primary fixation period, the formation of intermediate fixation compounds is less extensive. The length of the primary fixation period is of practical interest. It is determined by preservative composition and concentration, temperature and wood species. Diagrams are given for Pinus sylv...
S-E Dahlgren
Moderate temperature fixation of CCA-C
1989 - IRG/WP 3522
Several Canadian treating plants are using moderate temperature (40-60C°) fixation chambers to reduce drippage and leaching from fresh CCA treated wood. In this study, chromium reduction and surface leaching properties of CCA-C treated red pine (Pinus resinosa) pole sections were monitored during exposure to temperatures of 50-60C° and 90-100% RH conditions. Chromium-VI concentration in the abso...
P A Cooper, Y T Ung
Effect of species, retention and conditioning temperature on copper stabilization and leaching for ACQ-D
2004 - IRG/WP 04-30342
The time to stabilization or equalization of the copper component of ACQ-D was highly dependent on treating solution concentration (preservative retention) and post treatment temperature. Stabilization was rapid for low preservative retentions but extended times were needed for wood treated with higher concentration solutions. The extent of stabilization was also concentration dependent with a h...
Y T Ung, P A Cooper
The effect of initial moisture content on wood decay at different levels of gaseous oxygen concentration
1999 - IRG/WP 99-10316
The influence of initial moisture content on wood decay at different levels of atmospheric oxygen concentration was studied. Three fungi, Coriolus versicolor a white rot, Coniophora puteana a brown rot, and Chaetomium globosum a soft rot, were chosen. The mycelia of the fungi were inoculated on mini blocks of Fagus sylvatica (beech) and Pinus sylvestris (Scots pine). Incubations were under four le...
S M Kazemi, D J Dickinson, R J Murphy
Optimisation of an analytical method for the determination of total fluoride in preservative-contaminated soils using water steam distillation and an ion-selective electrode
1999 - IRG/WP 99-20153
This paper describes a simple modified procedure for the quantitative fluoride determination of different origin in a soil matrix using a water steam distillation and an ion-selective electrode. Distillation methods generally require a preliminary preparation step like fusing. The modified method presented here is based on the direct distillation of fluoride so that no further sample preparation i...
E Melcher
Estimation of the impregnation degree of pine wood by the distribution analysis of active ions concentration in the cross-section
1999 - IRG/WP 99-20174
Samples in the form of pine wood rollers of diversified moisture content of ca. 50, 28 and 12% were impregnated with a water solution of the mixture type CCB with the use of the full-cell process. Moisture content was determined in individual layers from the girth to the pith. In the same way the concentrations of copper and chromium ions with the use of the spectrophotometric method and recalcula...
K Lutomski, B Mazela
Assessing health risks to occupants following remedial insecticidal treatment of timber in dwellings
1998 - IRG/WP 98-50101-27
Experiments have been carried out to assess (i) the aerial concentrations of volatile wood preservative constituents, and (ii) the potential for contamination from treated surfaces, following in situ insecticidal treatment of timbers in dwellings. Using white spirit as a model for volatile constituents in the treatment of free-standing, wood-lined chambers indicated that temperature and air exchan...
R J Orsler, E D Suttie, V Rijckaert
A technical note on the limitations of atomic absorption spectrophotometric analysis of copper/chrome/arsenic solutions according to BS 4072 (1974) and BS 5666: Part 3 (1979)
1988 - IRG/WP 2320
British Standards BS 4072 (1974) and BS 5666: Part 3 (1979) detail an atomic absorption spectrophotometric method for the quantitative determination of copper, chrome and arsenic in both preservative solutions and treated timber. Use of this technique during a research programme at Aberdeen has highlighted some potential inaccuracies with this method if these standard specifications are adhered to...
A J Pendlebury, J A Petty
The production of extracellular hydrogen peroxide by some brown-rot fungi
1990 - IRG/WP 1446
The role of hydrogen peroxide (H2O2) has been discussed in the degradation of wood by wood-rotting fungi. The production of extracellular hydrogen peroxide was studied by detecting the oxidation of the chromogen 2,2'-azinobis(3-ethylbenzthiazoline-6-sulphonic acid) (ABTS) by H2O2 and horse radish peroxidase (HPR). ABTS and HPR were added to a solid wood based culture media. In this study ...
A-C Ritschkoff, L Paajanen, L Viikari
Minimum inhibitory concentration of methylene bisthiocyanate towards selected wood inhabiting fungi in liquid culture and on radiata pine
2001 - IRG/WP 01-30261
The objective of the current study was to determine the minimum inhibitory concentration (MIC) of methylene bisthiocyanate (MBT) towards wood inhabiting fungi common on unseasoned radiata pine (Pinus radiata D. Don). The fungi used were Ophiostoma floccosum, Leptographium procerum, Sphaeropsis sapinea and Trichoderma viride. Fungi were individually inoculated into nutrient media spiked with differ...
T Singh, B Kreber, C Chittenden, R N Wakeling, A Stewart
Detection of metabolic gas from termites using ceramic gas sensors
2001 - IRG/WP 01-20222
To evaluate termite attacks in wooden constructions by detecting the metabolic gas from termite colony, the basic performance of three types of ceramic gas sensors (odor-, methane- and hydrogen-selective sensors) was investigated. Four termite groups of different combinations of workers (100 to 1000) and soldiers (10 to 100) of Coptotermes formosanus Shiraki and a small specimen of Japanese red pi...
Y Yanase, Y Fujii, S Okumura, T Maekawa, K Suzuki, T Yoshimura, Y Imamura
Micromorphology of oak wood degraded by brown rot fungus Coniophora puteana
2000 - IRG/WP 00-10356
To characterize the degradation of hardwood by brown rot fungus, Coniophora puteana was incubated on the wood blocks of Quercus accutissima. For comparison, the same fungus was also incubated on the pine wood blocks of Pinus densiflora. In softwood, the shape of the wood cells and thickness of the cell appeared unchanged even the loss of birefringence in the affected areas. In contrast, oak wood d...
Yoon Soo Kim, Seung-Gon Wi, Kwang-Ho Lee
Leaching of components from CCF treated timber in ground contact
1998 - IRG/WP 98-50108
In order to investigate the depletion of different CCF-salts during service small stakes (10*10*450mm³) were treated with five water-borne wood preservatives and after fixation brought into ground contact for several years. After failing some of the broken down stakes were used to determine the remaining concentration of relevant ions and their distribution in different segments of the stakes.
A...
E Melcher
Experimental variations in the distribution of CCA preservative in lignin and holocellulose as a function of treating conditions (temperature, concentration, pH, species, and time)
1984 - IRG/WP 3277
The exact distributions between lignin and holocellulose and retentions on wood of copper, chromium and arsenic as a function of various sets of conditions in a 3x3x4x2 factorial experiment in which combinations of three temperatures of treatment, three CCA solution concentrations, four pH's of the initial CCA solution and two timber species, namely Pinus radiata and Eucalyptus grandis, a...
A Pizzi, E Orovan, M Singmin, A Jansen, M C Vogel
The resistance of wood coated with different water-borne paints against colonisation by decay fungi
1996 - IRG/WP 96-10165
The susceptibility of wood painted with model paints of known composition to decay fungi was tested without previous weathering. Included in the study were five alkyd emulsion paints and five acrylic paints; one linseed oil paint and two solvent-borne alkyd paints. It was found that several components influenced the susceptibility of these paints. The results of the present study indicate that the...
J Bjurman
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
Use of the Digital Refractometer for the On-site Analysis of Copper-based Preservative Systems
2007 - IRG/WP 07-20371
In some counties, there are no on-site chemical analysis methods available for treatment plants to use to determine the key active ingredients in the preservative treatment solutions. The complexity of the sophisticated methodology; cost of analytical instruments and training required for operating these instruments in treating plant level are the reasons for lacking such practice. In this paper...
L Jin, T Cashman, A Preston, J Trompetter, H Trompetter
Effects of bleaching process on the roughness values of wood surfaces of Lebanon cedar (Cedrus libani A. Rich.) and Black poplar (Populus nigra L.) using NaOH (sodium hydroxide), H2O2 (hydrogen peroxide) and Ca(OH)2 (calcium hydroxide)
2008 - IRG/WP 08-40403
Technical progress in the wood industry has been rapid in recent times. In this case, the quality assurance of the consumer products aligned with aesthetics value appears as one of the most important parameters. Because of the outer appearance of goods exert an effect on customers, interest in production of high quality surfaces of wooden commodities has increased essentially based on the surface ...
I Usta, E Aydinlar