Your search resulted in 81 documents. Displaying 25 entries per page.
Above-Ground Durability Estimation in Australia. Results after 16 years exposure
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
Predicting the decay resistance of timber above-ground: 1. Climate effects
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...
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
Modélisation sur maquette du rejet accidentel d'un gaz toxique et inflammable dans l'atmosphere - Emission de type "bouffée d'oxyde d'éthyléne [Water model simulation of toxic and flammable gases in the environment on industrial sites - Puff of ethylen oxide]
M Milhe
Rates of emission from CCA-treated wood in the marine environment: measurement, modelling and requirements for further research
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
Système informatisé d'aide à la décision pour la gestion de la migration du pentachlorophénol dans l'environnement
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
Preliminary results of investigations on screening test of chemical compounds suitable for the preservation of lignocellulosic materials against biodeterioration
This paper investigates the possibilities of reducing the time needed for the determination of the effectiveness of chemical compounds from the point of view of their eventual application to lignocellulosic materials for preservation against decay and soft-rot....
K Lutomski, S S Neyman
Report on International Conference on Marine Biodeterioration, Goa, India, January 1986
At the International Conference on Marine Biodeterioration - Advanced Techniques Applicable to the Indian Ocean, there were a number of papers relevant to the aims of Working Group IV of IRG. Abstracts of these papers and a brief commentary on the conference are presented....
S M Cragg
An Open Letter to Proponents of CLT/Massive Timber
We present an Open Letter that discusses the need to address the potential for biodeterioration in CLT/Massive timber structure. We invite members to review and sign the document. We also welcome suggestions for potential recipients....
A Taylor, J Lloyd, T Shelton
An in-ground natural durability field test of Australian timbers and exotic reference species. Part 2: Progress report after approximately 13 years' exposure
The condition of heartwood specimens of Australian and exotic timber species after approximately 13 years' in-ground exposure is given. Four of the 5 test sites have a termite hazard in addition to the hazard from a range of decay fungi. Values for specimen life are given only where all replicates of a timber species have become unserviceable. Results give evidence leading to doubt about ...
J D Thornton, G C Johnson, I W Saunders
Some physiological characteristics of a non-degradative strain of Postia (=Poria) placenta
The decay capacity of 14 strains of the brown-rot fungus Postia (= Poria) placenta was determined using soil-wood block tests. One isolate was identified as being unable to degrade wood and was determined to be monokaryotic. It retained the ability to produce extracellular carbohydrate-degrading enzymes, although regulation of certain enzymes was atypical under certain cultural conditions. It prod...
J A Micales, T L Highley
Efficacy of some extractives from Pinus heartwood for protection of Pinus radiata sapwood against biodeterioration. Part 1: Fungal decay
Chemical compounds thought to contribute to the natural durability of heartwood of Pinus spp. were either chemically synthesised in the laboratory or extracted from the heartwood of Pinus elliottii or Pinus caribaea. These compounds included the stilbenes, pinosylvin and its mono- and di-methyl ethers, and the flavonoids, pinobanksin and pinocembrin. Small blocks of Pinus radiata sapwood were impr...
M J Kennedy, J A Drysdale, J Brown
Kinetic modelling of adsorption of quaternary ammonium compounds by Scots pine wood sawdust (Pinus sylvestris L.)
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
Use of Transverse Compression Properties as a Measurement of Wood Biodeterioration, Part 1 of 2 - Effect of White-Rot on Yellow-Poplar
The soil block and agar block test methods are used extensively as a screening process for potential and modified wood preservatives. The extent of decay in standard screening tests, indicative of preservative efficacy, is currently based on mass loss. Mass loss techniques, due to their limit of sensitivity in detecting significant mass loss vis-à-vis decay, require an extended fungus exposure ...
S Janzen, D D Nicholas
Differential behaviour of wood rotters at water repellent Rubberwood
Rubberwood samples treated with different concentration of aqueous solution of chromic acid has induced significant increase in water repellency and attains dimensional stability. Though water repellency and dimensional stability was achieved by treatment, the fungal invasion could not be completely controlled. Differential level of decay of brown and white rot in wood treated with water repellent...
H C Nagaveni, S S Chauhan, K S Rao
Biodeterioration and preservation of rubberwood (Hevea brasiliensis)
Plantation-grown rubber trees (Hevea brasiliensis) in the tropics is fast emerging as a significant provider of quality hardwood for a variety of non-structural products, as the aesthetics of the timber is its creamed colour resembling perhaps the priced but depleting Ramin wood or even American beechwood. However rubberwood logs and sawn materials are highly sensitive to sapstain, fungal decay an...
L T Hong, A H H Wong
Natural durability of some common Indian timbers and marine plywood against biodeterioration in Kochi waters (India)
Panels of thirty-eight timber species and marine plywood were tested in Kochi harbour (South-west India) for periods ranging from 3 to 21 months, so as to evaluate their natural resistance against marine borers. Results indicate that all the timber species studied are non-durable, 6 of them having undergone more than 50% internal destruction within 3 months; 14 species in 6 months, 13 species and ...
L N Santhakumaran, M V Rao
Subterranean termites in Portugal. Tentative model of distribution
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
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
Analysis of degradation observed on ancient wooden objects buried underground
Ancient wooden objects were sometimes excavated from the moat of mounded tombs in Japan. Such wooden objects were in the shape of a sunshade, bird, shield, pole, yugi(a bag that holds arrows) among others. Archaeologists discussed the usage of such shaped objects, but no one could clearly explain their use. Some objects were observed using an ordinary microscope. Deterioration by bacteria was foun...
H Sakai
Examining environmental conditions and the biodeterioration of historic waterlogged wood: the Kolding Cog
Survival of waterlogged wood from thousands and in rare cases millions of years presents scientists with a unique opportunity to examine wood specimens which, due to select properties of the wood itself and/or the depositional environment, have not been completely degraded. This paper discusses the biodeterioration of a submerged shipwreck buried in Kolding Fjord, Denmark for the past 1000 years....
B A Jordan, D J Gregory, E L Schmidt
An engineering model for the decay of timber in ground contact
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
Modelling the control of decay in freshly felled pine poles
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
Model of termite distribution in Portugal - Follow-up
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...
Comparative study on leaching of CCA from treated timber: Modelling of emission data
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