Your search resulted in 44 documents. Displaying 25 entries per page.
Modelling the control of decay in freshly felled pine poles
1997 - IRG/WP 97-10206
In a recent study investigating control of decay in freshly felled pine utility poles, it became apparent that the efficacy of different treatment methods was strongly related to the size of the material being treated. A topical application of 5% w/v disodium octaborate tetrahydrate (DOT), brush applied to the cut surfaces of logs with otherwise intact bark was just as effective at excluding white...
M W Schoeman, W Van der Werf, J F Webber, D J Dickinson
Preliminary modelling of methylisothiocyanate movement through Douglas fir transmission poles
1988 - IRG/WP 3466
Methylisothiocyanate is a volatile solid that is the active ingredient of several registered and experimental wood fumigants. Information on the sorption and diffusion of this chemical in Douglas-fir heartwood and sapwood was used to develop a two-dimensional model of fumigant movement within a single horizontal cross-section of a transmission pole. The model indicated that dry wood (14% MC) stron...
A R Zahora, P E Humphrey, J J Morrell
Studying fungal growth using automated image analysis and computer simulations
2016 - IRG/WP 16-20590
Wooden materials are prone to fungal attack resulting in damage and economic losses. Therefore many efforts have been made to understand the degradation of wood and to avoid the adverse effect of fungi. Even though the extent of degradation of a material is inversely proportional to the extension of the fungi attacking it, most researchers focus mainly on the former, leaving the study of the latte...
G Vidal-Diez de Ulzurrun, J M Baetens, J Van den Bulcke, B De Baets
Modelling of PCP migration in the environment: Feeding the models with laboratory data
1993 - IRG/WP 93-50001-08
In 1989, Hydro-Québec began a study program on pentachlorophenol (PCP) to ensure safe use of the product at all stages. One of the aspects of the study is the creation of a predictive system for evaluating the behavior of PCP and oil migration from wood poles to the environment. This system comprises four mathematical models for predicting PCP and oil migration in and on the surface of the pole, ...
A Besner, P Tétreault, R Gilbert
Soft rot cavity widening - A consideration of the kinetics
1984 - IRG/WP 1227
Studies on the micromorphology of soft rot cavity formation by Phialophora hoffmannii in birch using time-lapse cinemicrography are briefly outlined. A mathematical model is constructed to describe the cavity widening process, particularly changes in the surface area of a hypothetical cavity during enlargement. On comparison with observed data it is concluded that the rate of cavity widening is de...
M D C Hale, R A Eaton
Rates of emission from CCA-treated wood in the marine environment: measurement, modelling and requirements for further research
2001 - IRG/WP 01-50166-12
Accurate estimates of rates of emission of leachate from preservative treated wood are crucial for realistic predictions of the environmental impact of its use in maritime construction. Estimates are available for some commonly used preservatives, but these vary widely. Though variable, these measurements suggest that emission generally decreases exponentially with time. Part of the variation is d...
S M Cragg, C J Brown, R A Albuquerque, R A Eaton
Computerised data acquisitioning, handling and processing in wood preservation studies
1984 - IRG/WP 2218
The computerisation of data acquisitioning, handling and processing in weathering studies on wood treated with protective coatings is discussed. An integrated system comprising a data base, statistical package and a custom written graphical processor is explained. Two treatments are compared and the correctness of a mathematical weathering model is evaluated....
T Rypstra, K Vos
The proposal for optimalization of the agar-block method for wood preservatives fungitoxic evaluation
1995 - IRG/WP 95-20065
On the base of own research and other scientists results the proposal for optimalization of agar-block method was presented by:
- selection of test fungal species and strains and central distribution of their pure cultures,
- change of the treatment and control samples exposure procedure,
- application of mathematical estimation of toxic value results,
- shortening the duration of fungitoxic t...
J Wazny
Système informatisé d'aide à la décision pour la gestion de la migration du pentachlorophénol dans l'environnement
1993 - IRG/WP 93-50001-10
This paper describes a Decision Support System (DSS), concerning pentachlorophenol (PCP) migration in the environment. The principal objectives of the DSS are to assist managers in siting of PCP-treated poles in the Hydro-Québec system and the storage areas and in the treatment of customer complaints. Four mathematical models are incuded in the system: a model simulating migration inside and on t...
G Lefebvre, J-C Tessier
Kinetic modelling of adsorption of quaternary ammonium compounds by Scots pine wood sawdust (Pinus sylvestris L.)
2005 - IRG/WP 05-30369
The adsorption of new quaternary ammonium compounds from aqueous solutions onto Scots pine wood (Pinus sylvestris L.) sawdust was studied. The pseudo first- and second- order kinetic models were used for the mathematical description of the sorption dynamic process of QACs onto wood. The highest correlation coefficients were obtained for the pseudo-second order kinetic model, those suggest that che...
J Zabielska-Matejuk
Subterranean termites in Portugal. Tentative model of distribution
2002 - IRG/WP 02-10420
Although extensive references can be found on the presence in the last 50 years of Reticulitermes lucifugus (Rossi), in Portugal, its exact distribution and importance has never been critically evaluated.
Termites were found to be widespread in the country and are probably the most serious wood destroying insects in buildings.
To provide a future working tool that would permit an evaluation of t...
T Nobre, L Nunes
Testing a diffusion and reaction model for the leaching of CCA components from unfixed CCA-treated wood
2002 - IRG/WP 02-50193
A previously described physical model applicable to the leaching of any substance undergoing a first-order fixation reaction with wood is applied to the leaching of CCA components from unfixed wood. Using this model and laboratory leaching experiments with small wood samples immersed in water, the diffusion coefficients and reaction rate constant of Cr6+, total Cr, Cu and As in unfixed CCA-treated...
L Waldron, P A Cooper
An engineering model for the decay of timber in ground contact
2003 - IRG/WP 03-20260
To predict the residual strength of an engineered structure, it is first necessary to predict the effect of decay. A model was developed in which the effective area of structural decay in large section timbers was defined as that area that could be picked out with a pen-knife. Some limited studies indicated that for practical purposes the remaining wood could be assumed to have its full residual s...
R H Leicester, C-H Wang, M N Nguyen, J D Thornton, G Johnson, D Gardner, G C Foliente, C MacKenzie
Model of termite distribution in Portugal - Follow-up
2003 - IRG/WP 03-10470
In Portugal, subterranean termites of the genus Reticulitermes are indigenous and a well-established pest of wood in service. Mapping their distribution has therefore become important. A field sampling campaign was established along a North-South transect based on 50x50 km cells (Universal Transverse Mercator grid system, UTM). A variety of typical habitats, ranging from forest sites of Eucalyptu...
T Nobre, L Nunes
The mathematical study of test plot data
1987 - IRG/WP 2282
It has long been desirable to have a mathematical expression, which, by the insertion of statistically derived constants, would describe the behavior of test specimens in service. The philosophy of such expressions is briefly discussed, and the history of the concept is outlined. The modern approach to the problem dates from the graphical presentation of dosage-response and deterioration curves by...
W H Hartford
Comparative study on leaching of CCA from treated timber: Modelling of emission data
1994 - IRG/WP 94-50027
Results of a comparative study on leaching of CCA from treated timber are reported. The study aims at investigating the applicability of prestandard leaching test methods for modelling purposes. Prestandards used are the European standard proposed by CEN/TC38/WG11 and NEN 7345 (Dutch prestandard for building materials). Parameters of study are type of fixation, wood species (pine - spruce), specim...
G M F Van Eetvelde, M Stevens, L Van der Mijnsbrugge
Above-Ground Durability Estimation in Australia. Results after 16 years exposure
2005 - IRG/WP 05-20314
A program of research was established in 1987 to examine the above-ground durability of a selection of timbers that are commercially significant in Australia. Test samples were assembled in an L-Joint design and placed on exposure racks in a format to replicate joinery that is exposed to the weather above ground. Both painted and unpainted material has been exposed.
Test samples have been evaluat...
L P Francis, J Norton
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
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
Evaluation of impact of CCA-treated wood on the marine environment
1995 - IRG/WP 95-50040-15
This paper reviews the literature relating to the potential of CCA-treated wood to affect the marine environment and outlines the compounds required for a model which could be used to predict the environemental impact of maritime construction using such timber. Marine pilings require high loadings of CCA to provide protection from marine borers. Though loadings of 32-48 kg/m³ provide long-term pr...
R M Albuquerque, S M Cragg
The kinetics of anhydride modification reactions of wood. Experimental results and theoretical modelling
1998 - IRG/WP 98-40125
Although the chemical modification of wood remains a fertile area for research, there has been little work performed on the kinetics of the modification process. The reaction kinetics of a series of linear chain and cyclic anhydrides has been studied and activation energies of the reaction determined. The reaction kinetic profiles are determined by the relative rates of reaction of the reagent wit...
C A S Hill, J G Hillier
Modelling of copper emission fron treated wood leached according to NEN 7345 and ENV 1250.2
1996 - IRG/WP 96-20097
A series of water leaching experiments is carried out investigating pine and spruce treated and fixed using different copper-containing preservative solutions and process technologies. Water changes took place as prescribed in the Dutch standard NEN 7345 and the European test method ENV 1250.2, each of the leachates being chemically analysed for their copper content. Irrespective of the preservati...
G M F Van Eetvelde, S G L Michon, M Stevens
Predicting the decay resistance of timber above-ground: 1. Climate effects
2006 - IRG/WP 06-20330
Despite the benefits of using timber as a building product, it is disadvantaged by current Australian Standard durability classifications which lack the sensitivity desired by engineers and architects. To address the need for more sensitive timber service-life information in Australia, an above-ground durability research program was established in 1987. One focus of research is the relationship be...
L P Francis, J Norton
Evaluation of exposure conditions for wooden facades and decking
2009 - IRG/WP 09-20408
During their functional life, building components are exposed to moisture and other environment stress conditions in numerous ways. This is a fact that should be taken into account during manufacture, product development, designing and work execution of building components. For wood material, moisture stress and biological factors like mould and decay fungi are often critical in cladding and decki...
H Viitanen, T Toratti, R Peuhkuri, T Ojanen, L Makkonen