Your search resulted in 234 documents. Displaying 25 entries per page.
Rapid loss of lignin at wood surfaces during natural weathering
1992 - IRG/WP 92-2390
Thin veneers of radiata pine (Pinus radiata D. Don) were exposed to natural weathering over a period of 30 days. Incident UV radiation was monitored at the test site. FTIR internal reflectance spectroscopy was used to study the chemical changes taking place at the veneer surface during weathering. Spectra obtained show that after only 3 days exposure there was substantial delignification at veneer...
P D Evans, K J Schmalzl, A J Michell
Chemical treatment of ten Amazonian timber species of low natural durability
1991 - IRG/WP 3640
The objective of this work was to evaluate the performance of 10 amazonian wood species of low natural durability, to treatment with CCA preservative (2% concentration): it was concluded that all species studied are easily treated with this preservative. The sapwood showed high absorption and total penetration. The heartwood is relatively easy to preserve, exception to Parkia nitidae (Fava), Quale...
C S Neta, B F Vianez
Assessment of untreated Papua New Guinea timbers against subterranean termites. Final report
1993 - IRG/WP 93-10041
Four years after the exposure of eight timber species of varying density against subterranean termites in a field trial, Kwila was still generally sound while Taun, Malas and PNG Walnut were beginning to be attacked slightly to moderately. Calophyllum, Kamarere, PNG Beech and White Cheesewood were severely attacked and failed. Results after the period of exposure shows that Kwila rates highly as t...
H C Konabe, M Rokova
Laboratory tests on the natural durability of timber methods and problems
1984 - IRG/WP 2217
In literature a large variety of test methods is mentioned to examine the natural resistance of timber against fungal attack. This concerns the kind of sampling as well as the test procedure, the test fungi, the duration of test, and the classification of the resistance according to the test results. These variations, however, are of great influence on the test result. Long term exposure will lead...
H Willeitner
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
Implications for comparibility of laboratory experiments revealed in studies on the variability in survival and wood consumption between colonies of Coptotermes acinaciformis (Froggatt) (Isoptera: Rhinotermitidae
1983 - IRG/WP 1193
Groups of Coptotermes acinaciformis originating from six colonies, three taken from each of two localities 1500 km apart in northern Australia (Townsville, Darwin), were kept at population densities of 0.005, 0.011 and 0.02 g termites/mL. Survival and wood consumption of the groups after 8 weeks followed a similar pattern in the colonies from both collection areas. Groups were least vigorous at th...
M Lenz
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
Observations on the destruction of fishing craft in India by marine wood-borers with special reference to the West Coast
1981 - IRG/WP 468
The paper highlights the economic importance of the destruction of fishing craft in India by marine wood-destroying agencies. The annual loss involved is to the extent of over 94 million rupees. Thirty-nine spectes and one variety of woodborer have so far been recorded from India, of which Bankia campanellata, Bankia carinata, Bankia rochi, Dicyathifer manni, Lyrodus pedicellatus, Teredo clappi, T...
L N Santhakumaran, J C Jain
Influences of the hydro-thermal treatment on physical properties of beech wood (Fagus orientalis)
2005 - IRG/WP 05-40303
Influences of the hydro-thermal treatment on physical properties of beech wood were studied. Wood specimens (2×2×2cm) were treated in two steps. At first step, samples were treated at 160,180 & 200ºC for 4, 5 & 6 hours. At second step, treated samples were cured based on their first step treatment temperatures (160,180 & 200ºC) for 16 hours. The treated samples were soaked in water...
B Mohebby, I Sanaei
Assessing the importance of degradation mechanisms on the loss of effectiveness of wood preservatives
2000 - IRG/WP 00-20193
Accelerated ageing systems developed for application to samples in the laboratory prior to biological tests, should reflect those natural deterioration processes that are likely to occur in the hazard classes defined in EN 335-1. Losses through evaporation or the effects of leaching have been recognised, however their importance, relative to other mechanisms has not been quantified. Degradation me...
E D Suttie, R J Orsler, T Dearling
Nasutitermes exitiosus and wood-rotting fungi in Eucalyptus regnans, E. acmenioides, E. wandoo, and E. marginata: force-feeding, laboratory study
1985 - IRG/WP 1231
Under a force-feeding regime, the termitid Nasutitermes exitiosus was fed on four eucalypt timbers infested with several fungal species to investigate the influence of such fungus-infested timbers on mass of wood lost, termite biomass, fat content and water content. The results showed that wood mass losses were markedly affected by species of fungi and timber. The interaction of fungi and timbers ...
D B A Ruyooka
Wood decay of Pinus sylvestris L. and Fagus sylvatica L. by marine fungi. Part 2
1991 - IRG/WP 1471
The water-logged wood conservation requires a good knowledge of the wood decay organims which produce the degradation. Previous conducted studies (ESCORIAL, TROYA, GARCIA DE LOS RIOS, 1990) have shown that the incubation times normally used for in vitro laboratory tests are not sufficients for a significant wood degradation. This has been the reason why the aim of this work was the study of such d...
M T De Troya, A M Navarrete, M C Escorial
Developments in unsterile soil soft rot testing
1984 - IRG/WP 2210
Two unsterile soil test methods, the soil burial technique and a method using vermiculite burial with soil inoculation, were compared using different soils to determine their effectiveness in evaluation of wood preservatives against soft rot. Isolation of fungi and microscopy of decayed wood indicated that both methods produced accelerated soft rot attack in treated and untreated birch. Vermiculit...
P A McKaig
Silicon tetrachloride: A potential wood preservative
1980 - IRG/WP 3133
In its present form, this paper is a preliminary draft of a paper that will eventually be submitted for publication in the Forest Products Journal. We are continuing the work on the effects of silicon tetrachloride on wood and expect to have additional data for the meeting in May 1980. Specifically we are measuring the penetration rate and depth of SiCl4, and we are chemically analyzing the treate...
C W Owens, W T Shortle, A L Shigo
Estimation of mycelial biomass by determination of the ergosterol content of wood decayed by Coniophora puteana and Fomes fomentarius
1989 - IRG/WP 1415
The mycelial biomass of fungi decomposing wood materials may be estimated by the use of an ergosterol assay technique.ln decay tests, essentially according to EN 113, estimates made by HPLC analyses on wood decayed by Coniophora puteana and Fomes fomentarius show the increase in biomass in the wood blocks. The ergosterol contents were correlated with dry weight loss determinations. Degradation of ...
K Nilsson, J Bjurman
Effect of moisture and cellulosic substrate on decay of hardwoods by soft-rot fungi
1982 - IRG/WP 2173
The development by Forintek Canada Corp. of standard test procedures for laboratory preservative evaluations using soft-rot fungi was requested by the American Wood Preservers' Association. In Europe, through cooperative studies in the International Research Group on Wood Preservation, several attempts have been made to produce a standard procedure, but variability in results obtained bet...
A Byrne, R S Smith
Assessment of untreated Papua New Guinea timbers against subterranean termites. Progress report 2
1993 - IRG/WP 93-10040
Eight species of Papua New Guinea wood including Kwila (Intsia palembanica), Taun (Pometia pinnata), Malas (Homalium foetidum), PNG Walnut (Dracontomelon dao), Calophyllum (Calophyllum sp.), Kamarere (Eucalyptus deglupta), PNG Beech (Nothofagus spp.) and White Cheesewood (Alstonia scholaris) were exposed groun contact for their natural durability against subterranean termites. Inspection after 42 ...
M Rokova, H C Konabe
Collaborative soft rot tests: Statistical treatment of results of soil analyses
1971 - IRG/WP 29
Institutes taking part in the collaborative experiments already reported forwarded samples of the soils employed in the tests to the Forest Products Research Laboratory, England. The soils were then autoclaved sterilised under uniform conditions and sent to the Department of Forest Soils, the Royal College of Forestry, Stockholm, Sweden. The results of the soil analyses are given in Table 1, toget...
A F Bravery
Fixation of CCA preservatives in cocos-, oil- and rattan-palm
1986 - IRG/WP 3371
In previous tests with jubaea-palm almost no fixation of a CCA-preservative Type B could be achieved, consequently, further leaching tests were carried out with samples of 1 cocos-, 1 oil- and 2 rattan-palms from Malaysia. A good fixation of chromium and copper took place in cocos-palm after 4 weeks storage at 28°C. Nevertheless the fixation was slower than in pine-wood and demanded an elevated t...
H Willeitner, K Brandt
Evaluation of the natural durability and ultrasonic method for decay detection of some european hardwood and softwood species
2004 - IRG/WP 04-10537
This paper presents the first part of an investigation on the natural durability of mixed plywood made of durable and non durable plies from the following selected timbers : Cedrus atlantica, Cupressus sempervirens, Castanea sativa, Populus sp. I 214 and Fagus sylvatica.
In order to carry out this study, the natural durability of the massive wood used to manufacture the plywood panels was asses...
F Faraji, M-F Thévenon, B Thibaut
Use of compression strength loss for measuring decay in the soil block test
1996 - IRG/WP 96-20083
The possibility of using radial direction compression strength of wood, rather than mass loss, was evaluated for both a brown-rot fungus (Gloeophyllum trabeum) and white-rot fungus (Trametes versicolor). With untreated pine wafers (5 x 19 x 19 mm³ - l x r x t) exposed to Gloeophyllum trabeum in a soil block test for five days, the compression strength loss was nearly 50% compared to a 5% mass los...
D D Nicholas, Zhongwei Jin
Computerized axial tomography. A non-destructive method for three-dimensional wood density/moisture content measurement
1987 - IRG/WP 2285
Computerized Axial Tomography (CAT-scanning) - used for medical investigations of the brain - has been evaluated as a nondestructive method of three-dimensional wood density/moisture content measurements. Density can be measured with an accuracy of ±3 kg/m³, and the accuracy in average moisture content is ±1% below and above fibre saturation point. It is theoretically possible that measurements...
L O Lindgren
The relationship between basic density and liquid absorption in fast, plantation grown 8 Year Old Eucalyptus pellita and E. Urophylla
2002 - IRG/WP 02-40220
The liquid absorption characteristics of 8 year old Eucalyptus pellita and E. urophylla were studied in order to gain insight into the treatability of this young, fast grown eucalypt plantation resource. The trees were grown in an experimental plantation trial near Innisfail in northeast Queensland.
The study demonstrated that average sapwood basic density in young plantation grown E. pellita a...
J Norton, A Muneri
Implications for comparability of laboratory experiments revealed in studies on the effects of population density on the vigour in groups of Coptotermes lacteus (Frogatt) and Nasutitermes exitiosus(Hill) (Isoptera: Rhinotermitidae, Termitidae)
1983 - IRG/WP 1194
The vigour - survival. and wood consumption - of groups of Coptotermes lacteus and Nasutitermes exitiosus was measured when termites were kept at different population densities (g termites/mL) by changing group size and/or volume of the holding container. A characteristic pattern emerges for subterranean-like termite species. At low population densities (<0.01 g/mL) performance of termites impr...
M Lenz, R A Barrett, E R Williams
The loss of insecticidal action from synthetic pyrethroid-treated wood samples: The effect of high temperatures and relative humidities
1992 - IRG/WP 92-1569
This paper describes the results from bioassays using Hylotrupes bajulus, and chemical analyses, of pyrethroid-treated wood samples following storage for up to 3 years. A range of four storage environments was used consisting of combinations of two temperatures (20°C and 40°C) and two relative humidities (60% and 90%). It is concluded from the chemical analyses that, although losses at room temp...
R W Berry, S J Read