Your search resulted in 183 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
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
The comparative resistance to fungi of the wood munika (Pinus heldreichii Christ.), fir (Abies alba Mill.) and spruce (Picea excelsa Poir.) compared with Pinus sylvestris L. and some physical and mechanical characteristics of munika
1981 - IRG/WP 1129
The munika (Pinus heldreichii Christ.) is situated primarily in the Balkans, and partially in the south of the Apenine peninsula. As an endemic species, with a very little annual increment, it has not been used enough as a timber for mechanical conversion up till now, although the oldest trees can grow to 27 m in height, with a diameter at breast height of about 60 cm. According to data of many Ba...
M Petrovic, M Miric
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
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
Influence of variable lignin content amongst hardwoods on soft-rot susceptibility and performance of CCA preservative
1982 - IRG/WP 1151
This paper presents the outline of an argument, based on both new and established data, which relates varying lignin content to variation of soft-rot susceptibility between hardwood species and of performance of CCA preservatives in controlling soft-rot. Although more data need to be generated to prove this relationship, sufficient evidence exists for the hypothesis to be given close attention, pa...
J A Butcher, T Nilsson
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
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
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
Application of non-destructive techniques (durometric and ultrasonic) to evaluate the degradation of woods in service by Gloeophyllum trabeum
2001 - IRG/WP 01-20220
In order to establish the degree of degradation of wood used in construction, it is necessary to employ non-destructive methods (ultrasonic, durometric, densitometric). In this study, ultrasonic and Pilodyn durometric techniques have been applied to try to establish parameters of relationship between the values obtained by both, for their immediate application to wood in service. As a method of re...
M T De Troya, L Palaia, A Navarrete, V Galvañ, R Molina, A Guijarro, J Camacho
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
The effect of added nutrients on growth rate and decay capacity of Serpula lacrymans
1990 - IRG/WP 1427
At the previous meeting a new technique was presented that enables both fungal growth rate and wood decay rate to be measured using the same timber specimen. The technique (IRG/WP/1384) has previously been carried out with 1% malt as the sole nutrient within the small jar that provides the inoculum for this method. Results presented here relate to an additional level of 5% malt, with or without a ...
J D Thornton, A McConalogue
Effect of aqueous polymer treatments on wood properties. Part 2: Mechanical properties
1990 - IRG/WP 3611
Partially air-dried sapwood of sweetgum (Liquidambar styraciflua) and southern pine (Pinus spp.) was treated with either aqueous polyacrylate or aqueous dimethyloldihydroxyethyleneurea (DMDHEU) solutions. Tests for static bending, toughness, and hardness were conducted on matched treated and untreated pieces according to ASTM Standards. Properties of pine were not affected by treatment with the po...
Z Ashaari, H M Barnes, D E Lyon, R C Vasishth, D D Nicholas
Collaborative soft rot tests: Final Report
1978 - IRG/WP 2106
Since preparation of Document No: IRG/WP/258 results have been received from the remaining collaborators. Thus there is a little further to add to the conclusions already derived, those in Document No: IRG/WP/251 being as follows: 1) the exposure system used sometimes resulted in excessive weight gains in the sterile check blocks. Consequently the corrected loss in weight of the test blocks could ...
J G Savory, J K Carey
The effect of aqueous leaching on moisture uptake by CCA-treated blocks during soil burial
1987 - IRG/WP 2283
Mass loss, moisture content and nitrogen data from two soil burial experiments with untreated and CCA-treated Scots pine (Pinus sylvestris L.), Sitka spruce (Picea sitchensis Carr) and lime (Tilia vulgaris Hayne) are presented. These show that aqueous leaching of CCA-treated wood prior to burial significantly reduces its subsequent moisture uptake from soil. In the case of lime, a reduction in the...
C A Green, G M Smith, B King
A quantitative weathering study of wood surfaces modified by chromium VI and iron III compounds
1989 - IRG/WP 2330
Thin veneers of Pinus radiata were treated with dilute aqueous solutions of chromium VI and iron III compounds and exposed to natural weathering for 35 days. Zero-span tensile strength and weight losses of treated veneers were compared with losses observed in untreated specimens In a study designed to demonstrate the applicability of strength and weight loss measurements to the rapid quantitative ...
P D Evans, K J Schmalzl
Relationship between the bending strength and the degree of termite attacks on western hemlock by Coptotermes formosanus Shiraki
1990 - IRG/WP 1434
For the examination of the relationship between the bending strength and the degree of termite attacks, Western Hemlock (Tsuga heterophylla Sarg.) was used. Sixty specimens (4.5 x 4.5 x 82 cm³) were attacked by termites at the culture room of Coptotermes formosanus Shiraki. The termites were introduced on the central parts (10 cm) of specimens. In the case of the 2 points loading, the bending mom...
K Suzuki, T Tanaka
Biodetioration and strength reductions in preservative treated aspen waferboard
1983 - IRG/WP 2195
Experimental aspen waferboards, bonded with liquid or powdered phenol formaldehyde resins and treated by various methods with a wide selection of preservatives, were tested for fungal resistance in accelerated laboratory trials. Mold growth on the surface as well as weight and strength losses due to the actions of decay fungi were determined. Testing of board strength after decay in high and moder...
E L Schmidt, H J Hall, R O Gertjejansen, R C De Groot
Biological durabilityof cement-bonded particleboard
1997 - IRG/WP 97-20115
Cement-bonded particleboard (CBP) is a panel product manufactured from a combination of wood particle and cement with various ratio. The wood particle is used as reinforced material and the cement as an inorganic binder. Because of its many excellent properties, such as high weathering resistance, sound attenuation, and good acceptance for a range of surface treatments, CBP is widely used as a fac...
Qiao Wang, M Takahashi