Your search resulted in 72 documents. Displaying 25 entries per page.
Xenon simulation of natural weathering of external joinery preserving - Finishing systems
1992 - IRG/WP 92-2412
Semitransparent wood stains ('lazures') for external joinery have developed by means of product combination towards complete wood finishing systems that are easy to applicate, have a good weathering resistance and low maintenance cost. The search for enhanced formulations and the possibilities to standardize these products or treatment systems are always facing long periods of we...
J Van Acker, M Stevens, M Nys
Assessment of dehydrogenase activity, fluoride content and total chromium content of soil profiles exposed to preservative treated wood within a model system
1993 - IRG/WP 93-10015
The development and prospective use of a closed model system to facilitate study of a number of indicators of environmental impact of wood preservatives laboratory conditions has been described (IRG/WP/2395-92). Chemical analysis of leachate samples collected from drained soil profiles containing creosoted pole sections remedially treated with a chromated fluoride preservative indicated small incr...
G M Smith, D C R Sinclair, A Bruce, H J Staines
A new model for wetting and drying of wood end-grain – with implications for durability and service-life
2011 - IRG/WP 11-20477
New experimental data for wetting and drying of wood end-grain, Sandberg (2009), imply that traditional models for moisture transport are not at all applicable. A new model is developed to consider the phenomenological behaviour of water transport in and out of end-grain, using the pore water pressure and sorption scanning properties. Modelling results are compared to experimental results and the ...
L-O Nilsson, K Sandberg
Initial results and observations of a model system to assess the efficacy and environmetal impact of preservative treated wood
1993 - IRG/WP 93-50001-02
The development of a closed model system for the laboratory assessment of the efficacy and environmental impact of a chromated fluoride remedial treatment for creosoted distribution poles has been described (IRG/WP/2395-92). The model consists of a precipitation apparatus above a treated pole section positioned in a soil profile from which leachate was collected via a series of simulated field dra...
D C R Sinclair, G M Smith, A Bruce, H J Staines
Reaction of osmium tetroxide with a diphenolic compound as a model substance for demethylated lignin
1986 - IRG/WP 1303
By using caffeic acid as a model substance for diphenolic moieties of demethylated lignin it was found that electron dense particles called by the authors "osmiophilic particles" in former papers are reaction products of OsO4 with the model substance. By these products it is possible to indicate the enzymatic demethylation of lignin taking place during wood decay. The appearance of the electron de...
K Messner, E Srebotnik
Délavabilité de bois ronds traités avec un sel CCA dans des conditions réelles de stockage. Incidence pratique de la fixation accélérée par étuvage. Impact effectif sur l'environnement
1993 - IRG/WP 93-50001-23
Un essai de terrain a été organisé pour mesurer concrètement, dans des conditions aussi proches que possibles des conditions réelles de terrain, les pertes effectives en produit de traitement lorsque le bois traité est soumis à des intempéries. L'essai a été conduit sur des bois ronds (poteaux), traités en autoclave par procédé Bethell avec un sel CCA de type C, avec comme fi...
M Rayzal, F Larroze
Proposed model for the penetration and decay of wood by the hyphal sheath of the brown-rot fungus Postia placenta
1989 - IRG/WP 1391
Scanning electron microscopy (SEM) of Pinus sp. decayed by the brown-rot fungus Postia placenta confirmed the existence of extracellular membranous structures previously described by transmission electron microscopy (TEM). These structures appear to be an integral part of the hyphal sheath and assume a variety of forms including lamellar sheets, fibrils, and vesicles. These structures were observe...
F Green III, M J Larsen, L L Murmanis, T L Highley
Degradation of lignin model compounds with coordinated copper in the presence of peroxide
1998 - IRG/WP 98-10282
A novel diffusible system capable of decomposing lignin model compounds with copper, coordinators and peroxides has been proposed. When pyridine was used as a copper coordinator, two synthetic dyes, Poly-R and RBBR were intensively decolorized with Cu(II) and H2O2 in aqueous solutions at room temperature. Although reactions with Cu(II) and H2O2 produce a strong oxidant, hydroxyl radical, via a Fen...
K Koller, K Messner, T Watanabe
The impact of global warming on the UK distribution of house longhorn beetle Hylotrupes bajulus (L)
2001 - IRG/WP 01-10414
This paper reviews the effects of global warming on insect populations and distribution. The affects of global warming on the spread of Hylotrupes is predicted through a review of research related to the influence of temperature on its life-cycle and flight. Records of Hylotrupes distribution were obtained from published surveys, entomologists and museum collections and were plotted for the UK. Th...
P Oevering, A J Pitman
Dimensional lumber model demonstrates the sensitivity of the particle capture immunoassay in early detection of brown-rot fungi
1995 - IRG/WP 95-20058
A dimensional lumber model was designed to test the sensitivity of the particle capture immunoassay (PCI) compared to traditional methods of culturing and microscopic examination for detection of brown-rot fungi. Southern yellow pine 2 x 4's (5.1x10.2 cm²), and 86.4 cm in length, were inoculated on one end with the brown-rot fungus, Postia placenta, and tested over the full length of the...
C A Clausen, L Ferge
Rainfall simulation to assess CCA permanence
1991 - IRG/WP 2373
During experimental work on accelerated fixation of chromium containing preservatives a method has been developed which compares the degree of preservative levels of contamination of simulated preservative fixation in timber with the levels of simulated rainfall. This method uses commercial sized wood sections wetted in a way that simulates actual rainfall and relates the associated run-off contam...
P Warburton, J A Cornfield
Development of a model system to assess the efficacy and environmental impact of a chromated fluoride remedial treatment for creosoted distribution poles
1992 - IRG/WP 92-2395
A closed model system was designed to facilitate a controlled study of the leachability and environmental fate of a remedial preservative under laboratory conditions. The elements of the model include a precipitation apparatus above a treated pole section which is positioned in a representative soil profile supporting a sward of perennial ryegrass. The model will allow detailed examination of the ...
D C R Sinclair, G M Smith, A Bruce, B King
Patterns of decay in CCA-treated horticultural post populations - A fungus cellar simulation
1986 - IRG/WP 1286
The distribution of decayed posts in 10-, 14-, and 18-year-old vineyards supported a hypothesis to explain variability in intensity of decay found among posts in New Zealand horticultural properties. The development of decay patterns between samples in a simulated vineyard plot established in the Forest Research Institute fungus cellar gave additional support to the hypothesis that decay within la...
M E Hedley
Preservative treatment of wood by diffusion processes - Simulation of commercial treatment processes
1988 - IRG/WP 3498
Spruce (Picea abies), Scots pine (Pinus sylvestris) and birch (Betula pendula) were preservative treated by diffusion with mixtures of copper sulphate and arsenic pentoxide. The preservative was fixed after a suitable diffusion storage period by soaking in ammonia solution. A high standard of treatment could be achieved in spruce sapwood. This was attributed to its low wood density, and high wood ...
P Vinden
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
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
Industrial fixation systems: key factors, limitations and optimisation through the use of computer simulation modelling. Discussion paper
1994 - IRG/WP 94-40026
This paper briefly describes four fixation operative in the Netherlands, namely: circulating and non-circulating steam fixation cylinders, steam fixation chambers and controlled climate rooms. The general limitations of industrial practice are reviewed against the background of established fixation theory. The controlling variables, both material and process-related, for fixation processing are sp...
A J Pendlebury, M Riepen, M J Boonstra, W Gard
Comparison of Temporal Changes in Metal Leaching and Aquatic Toxicity from Wood Treated with CCA and Alternative Preservatives
2005 - IRG/WP 05-50236
This study compares the temporal variation of chemical leaching and aquatic toxicity of wood treated with chromated copper arsenate (CCA) and other copper-based wood preservatives (alkaline copper quaternary (ACQ), copper boron azole (CBA), copper citrate (CC) and copper dimethyldithiocarbamate (CDDC)). Treated wood blocks were leached for 21 days and the leachate collected was analyzed for prese...
B Dubey, T G Townsend, G Bitton, H M Solo-Gabriele
A diffusion and reaction model for the leaching of Cr-VI from unfixed CCA-treated wood
2001 - IRG/WP 01-50169
A physical model applicable to the leaching of any substance undergoing a first-order fixation reaction with wood is presented. Using this model and a laboratory leaching experiment with small wood samples immersed in water, the radial and tangential diffusion coefficients and the reaction rate constants of Cr-VI in unfixed CCA-treated red pine (Pinus resinosa Ait.) are measured. Reaction rate con...
L Waldron, P A Cooper
Accelerated anti-termite laboratory tests, simulation of field conditions and assessment of results for service life
1994 - IRG/WP 94-20034
Termites are one of the most serious biodegrading agents in the tropics. Though some species of termites occur in the warmer temperate regions, only a few species can withstand the rigours of colder regions. Testing of termite resistance of material is done either by field tests or by accelerated laboratory tests. Field tests, though realistic to assess service life, are elaborate, take a long tim...
P K Sen-Sarma
Three-dimensional modeling of fumigant distribution in wood poles
1993 - IRG/WP 93-30025
The practice of using fumigants to control internal decay has been widely accepted in the United States and has shown to be effect in control internal decay in transmission poles and other large wood timbers. Mathematical models were developed to simulate the chloropicrin movement in utility poles after treatment. The simulation results indicated that treatment of utility poles, using either tradi...
Jing Liu, B Goodell
A model for attack at a distance from the hyphae based on studies with the brown rot Coniophora puteana
1995 - IRG/WP 95-10104
In timber infested by brown rot fungi, a rapid loss in strength is attributed to production of hydroxyl radicals (HO·) at a distance from the hyphae. The immediate precursor is Fenton's reagent (Fe(II)/H2O2), but the pathways leading to Fe(II) and H2O2 have remained unclear. Cellobiose dehydrogenase, purified from cultures of Coniophora puteana, will couple oxidation of cellodextrins to ...
S M Hyde, P M Wood
Moisture Adsorption Behaviour of Rubber Wood Decayed by Brown and White rot Fungi
2005 - IRG/WP 05-40306
Moisture adsorption behaviour of rubber wood blocks decayed by each brown rot and white rot fungi was studied. The adsorption isotherms of decayed wood were compared with the isotherm of undecayed wood. The wood decayed by brown rot adsorbed less moisture as compared to sound or undecayed wood at all humidity levels. No significant difference was observed in adsorption behaviour of white rot dec...
S S Chauhan, H C Nagaveni
Field Liners as physical barriers to prevent wooden utility pole decay in soil: An accelerated field simulation trial
2008 - IRG/WP 08-20384
Field Liners (FL’s), plastic sleeves used to protect in-ground wooden poles from fungal and termite damage, have been tested before as physical barriers to prevent contact between soil and wood and to retain wood preservative treatment. These earlier studies concentrated mostly on creosote preserved poles and early generation FL’s which were cumbersome in their application. The newer generatio...
A R Howgrave-Graham, L J Cookson, T Hale
Service life prediction of wood: scale-dependent tools within a bio-engineering framework
2008 - IRG/WP 08-20387
Service life prediction (SLP) is a complex yet essential method for the building industry. Accurate and precise assessment of the components is crucial for a strong position of wood on the market. As it is a biological material, wood has an inherent variability and is susceptible to fungal attack. Therefore a profound knowledge of these characteristics is the corner stone of SLP for wood products....
J Van den Bulcke, J Van Acker, M Stevens