Your search resulted in 235 documents. Displaying 25 entries per page.
Screening of fungal strains for wood extractive degradation
1998 - IRG/WP 98-10254
Fungal strains were screened for their ability to degrade apolar extractives in wood from scots pine. The degradation of total wood extractives by 91 different strains was monitored in stationary batch assays incubated for 6 weeks. The results obtained show that the ability of wood-inhabiting fungi to utilize wood extractives varied greatly, even for different isolates of the same species. Fungal ...
J Dorado, M J Martinez-Inigo, T A van Beek, F W Claassen, J B P A Wijnberg, R Sierra-Alvarez
Differential retention and leaching of CCA (C) in sapwood and heartwood of Kenyan-grown blue gum (Eucalyptus saligna) and black wattle (Acacia mearnsii)
2005 - IRG/WP 05-30371
Retention and leaching of CCA(C) in small samples of sapwood and heartwood of Kenyan-grown blue gum (Eucalyptus saligna) and black wattle (Acacia mearnsii) were tested under laboratory conditions. Clear samples (100mm x 30mm x 40mm) were removed from the sapwood and heartwood of sampled defect-free and sound plantation trees of the two species. These were separately air-dried to 15% MC, end-seal...
R Venkatasamy
Dominant genera of fungi isolated from the surfaces of Sugi (Cryptomeria japonica D. Don) heartwood lumbers exposed at six test sites from northern to southern regions of Japanese islands
1999 - IRG/WP 99-10304
The surfaces of wood materials are disintegrated not only by sunlight and rainwater but also by microbes when exposed above ground condition. This paper deals with the investigation of fungi isolated from the surfaces of Sugi heartwood lumbers (W100 by T10 by L300 mm) exposed at an angle of 45° without ground contact for 16 months at the six test sites from northern to southern regions of Japan. ...
S Doi, M Mori, M Kiguchi, Y Imamura, M Hasegawa, S Morita, S Nakamra, Y Kadegaru
Preliminary investigation on the natural durability of Guayule (Parthenium argentatum)-based wood products
2000 - IRG/WP 00-40154
Conventional preservatives used to protect wood from insect and microbial damages are presently of major concern to human health and the environment. Finding alternative and economical preservatives has not been successful. Previous studies have shown that the resinous material extracted from the guayule plant (Parthenium argentatum, Gray) has both insect- and microbial-resistant properties. Unfor...
F S Nakayama, P Chow, D S Bajwa, J A Youngquist, J H Muehl, A M Krzysik
The resistance of timbers to impregnation with wood preservatives
1979 - IRG/WP 3137
It is anatomical structure which determines liquid flow rate within different timber species. This cannot be deduced from properties such as density or rate of growth, and can only be found by experiment. A standard test has been in use at the Princes Risborough Laboratory for many years, employing a pressure-impregnation treatment, and a large number of timbers have been studied. The test consist...
Anonymous
Neem leaves, a potential source for protection of hardwood against wood decaying fungus
2005 - IRG/WP 05-30370
Neem leaves are widely recognized for their insecticidal, pesticidal, fungistatic and fungitoxic ability. The present study is to investigate the efficacy of neem leaves extractives against wood destroying microbes, a brown and a white rot. Neem leaves extractives prepared in various solvents such as petroleum ether, acetone, ethanol, methanol and hot water were tested at a concentration levels of...
S Dhyani, S Tripathi, V K Jain
Degradation of resin constituents in various wood species by the white rot fungus Bjerkandera sp. strain BOS55
1999 - IRG/WP 99-10301
In previous studies, the white-rot fungus Bjerkandera sp. strain BOS55 was shown to cause extensive degradation of lipophilic extractives (resin) in Scots pine wood. Further research was carried out in order to investigate the ability of Bjerkandera sp. for reducing resinous constituents in various softwood (Douglas fir, larch and spruce) and hardwood species (birch, beech and poplar). The greates...
J Dorado, T A Van Beek, F W Claassen, R Sierra-Alvarez
Penetration and absorption of water-borne preservatives in conifers from the Western United States: A preliminary report
1988 - IRG/WP 3475
The treatment of most softwoods from the western United States with waterborne chemicals poses a major challenge. Although many of these species are commercially treated with waterbornes, there is considerable debate about their treatability. At present, there is little or no information on the treatability of western wood species with waterborne chemicals. The lack of accurate treatability inform...
S Kumar, J J Morrell
Partial characterization of inhibitors extracted from pine (Pinus sylvestris) sapwood active against germination of wood rotting fungi
1988 - IRG/WP 1351
Germination inhibitors in pine sapwood could be extracted and separated with the aid of solvent partitioning and chromatography on silicic acid. The inhibitory action was tested by three different bioassays. Active fractions have been characterized by TLC and HPLC. Inhibitory activity could be correlated with phenolic compounds. The minimum active concentration of inhibitors have been determined....
J Bjurman
Influence of water soluble extractives on CCA fixation and leaching performance of red maple and red oak
1997 - IRG/WP 97-30133
We have observed several peculiarities in relation to CCA fixation in red maple and red oak woods such as high variability in fixation rates and leaching performance in maple and precipitate formation in solutions expressed from CCA treated red oak wood blocks at different stages of fixation. We have postulated that the extractives could be the factor of influence, as this has already been reporte...
T Stevanovic-Janezic, P A Cooper, Y T Ung
Analysis of the boron content of preservative treated oak and pitch pine heartwood before and after leaching
1992 - IRG/WP 92-3697
Studies to determine the effects, if any, of a variety of boron formulations on heartwood of English oak and American Pitch pine have been previously reported (King et al (1991)). Small wood blocks were treated, at 10°C or 45°C, with borax, polybor or Boracol 20 for periods of 1 month or 4 months then analysed or continuously leached with tap water for a period of 1 month. Reported results showe...
S McCutcheon, G M Smith, J W Palfreyman, B King
Fixation and leaching characteristics of Douglas-fir treated with CCA-C
2004 - IRG/WP 04-50213
Fixation and leaching characteristics of CCA-treated Douglas-fir was evaluated using the expressate method and the AWPA E11-97 leaching procedure. CCA fixation, as monitored by the chromium reduction, was much faster in heartwood than in sapwood; however, copper and arsenic fixation in heartwood appeared to be incomplete regardless of the extension of fixation time. This poor fixation of copper a...
Gyu-Hyeok Kim, Yun-Sang Song, Dong-heub Lee
Soft rot in heartwood of preservative-treated pole stubs of Eucalyptus cypellocarpa L. Johnson
1983 - IRG/WP 1204
Pole stubs of Eucalyptus cypellocarpa L. Johnson, treated in the sapwood with certain waterborne preservatives and exposed for 21 to 23 years in a dry tropical region were severely soft-rotted in the heartwood, as well as the sapwood. They broke with a brash fracture when stress tested (loaded as a cantilever) in the field. The severe soft rot in the heartwood was not detected by the knife test or...
J E Barnacle, G C Johnson, M A Tighe
Assessment of untreated Papua New Guinean timbers against subterranean termites. Progress Report 1
1990 - IRG/WP 1436
Eight major commercial timber species (Intsia palembanica, Pometia pinnata, Homalium foetidum, Dracontomelon dao, Calophyllum spp., Eucalyptus deglupta, Nothofagus spp., and Alstonia scholaris) were exposed in ground contact against termites. Five replicates of heartwood stakes of 25x25x250 mm³ of each species were randomly embedded in the soil. Results after 24 months exposure showed that Kwila ...
M Rokova, H C Konabe
Effects of heart wood extractives in Dahoma (Piptadeniastrum africanum) on decay resistance to white- and brown-rot fungi
2004 - IRG/WP 04-10536
Dahoma (Piptadeniastrum africanum) is a durable but a lesser utilised tropical hardwood species from Ghana that has the potential of being used as an alternative to Iroko (Milicia excelsa) for many end uses. However, the timber gives off a strong odour especially when wet and during processing. The high durability and the strong odour of the timber could be due to the presence of extractives in th...
Zeen Huang, K Maher, S A Amartey
Evaluation of extractives from African Padauk (Pterocarpus soyauxii Taub.) for protection of non decay resistant species
2002 - IRG/WP 02-10419
The development of a wood preservative made up of natural extracts is a potentially attractive prospect for the wood preservation industry. In this study, organic solvents were used to remove extractives from African padauk wood samples. The solvent was removed by rotoevaporation, and the total content of the viscous extracts determined to be 54.4mg/ml.
The toxicity of various extracts concentrat...
P Nzokou, D P Kamdem
Natural durability of tamarack (Larix laricina (Du Roi) K. Koch)
1998 - IRG/WP 98-10277
Eastern larch or tamarack (Larix laricina (Du Roi) K. Koch) lumber from New Brunswick, Canada was evaluated for heartwood natural durability according to ASTM D2017-81. The natural durability of tamarack heartwood exposed to two brown rot fungi, Gloeophyllum trabeum and Postia placenta was low and generally inferior to that of the heartwood of spruce (Picea sp.) and white pine (Pinus strobus L.) a...
U Srinivasan, A Taylor, P A Cooper
Resistance of pine and spruce heartwood against decay - The effect of wood chemical composition and coating with water-borne wood oil product
2006 - IRG/WP 06-10597
Natural durability of wood has been widely studied, but the combination of the natural durability and different treatments has not been the focus of many studies. The durability of wooden products is mainly based on the water permeability and the resistance against organisms. In this study, the water absorption and decay resistance of sapwood and heartwood of Scots pine and Norway spruce were exam...
H Viitanen, S Metsä-Kortelainen, T Laakso
The natural durability of wood in different use classes - PART II
2006 - IRG/WP 06-10598
The natural durability of important European wood species has been tested on 3970 speci¬mens in field trials. The wood was exposed at five test sites in Germany with different climates, at each site in European use class 4 and 3 (with and without soil contact). Within European use class 3 three different expositions were tested: vertical with sheltered end grain, vertical unsheltered and horizont...
A O Rapp, U Augusta, K Brandt
The effect of woody and non woody plants extractives on microbial resistance of non-durable species
2006 - IRG/WP 06-30392
The effect of Elm (Zelkova carpinifolia), Oak (Quercus castanifolia), Mulberry (Morus alba), Ash (Fraxinus excelsior) as woody plants, Rose (Rosa damascene) and Fumitory (Fumaria sp) as non woody plants extractives on durability of Beech (Fagus orientalis), Maple (Acer insgin), Alder (Alnus subcordata), and Lime (Tilia sp) were studied. First wood species having extractives were cut to small piece...
S M Kazemi, A Hosinzadeh, M B Rezaii
The Influence of Extractives on Western Redcedar’s Equilibrium Moisture Content
2006 - IRG/WP 06-40331
The high natural durability of western redcedar (Thuja plicata Donn) heartwood is often attributed to the presence of the thujaplicins, which are toxic to fungi. However, sound, twenty-five year old western redcedar shakes and shingles were found to contain only traces of the thujaplicins, but significant quantities of plicatic acid (which is only weakly toxic to fungi). This suggests that factors...
R Stirling, P I Morris
On the reasons of Prunus africana natural durability
2007 - IRG/WP 07-10611
Analysis of Prunus africana heartwood extractives was studied with the aim of understanding the reasons for its high natural durability. Soxhlet extractions of wood powder using different solvents were carried out. Effect of each extracts at different concentrations was evaluated on the growth of several fungi among which Coriolus versicolor, Poria placenta, and Aureobasidium pullulans. Results sh...
F Mburu, S Dumarçay, M F Thévenon, P Gérardin
Quantitative Determination of Cyproconazole in Wood treated with Tanalith CY
2007 - IRG/WP 07-20369
The HPLC method has been widely applied to quantitative determination of cyproconazole in preservative solutions. However, HPLC assay has not been successfully employed to determine cyproconazole content in treated wood. Some extractives from treated wood hinder cyproconazole determination because they have a similar retention time to that of cyproconazole on an HPLC chromatogram. In addition, ...
I Momohara, T Miyauchi, M Mori
Influence of Grain Direction on Penetration, Retention, and Leaching of CCA(C) in Sapwood and Heartwood of Kenyan-Grown Eucalyptus saligna and Acacia mearnsii
2007 - IRG/WP 07-40383
Penetration, retention, and leaching of CCA (C) in relation to grain orientation were tested in small (50mm x 50mm x 200mm) sapwood and heartwood samples of Eucalyptus saligna and Acacia mearnsii. In both sapwood and heartwood of the two species, the results showed a consistent pattern: Transverse > Radial > Tangential. Whereas penetration, retention, and leaching were significantly high i...
R Venkatasamy
Influence of Grain Direction on Penetration, Retention, and Leaching of CCA(C) in Sapwood and Heartwood of Kenyan-Grown Cupressus lusitanica and Pinus patula
2007 - IRG/WP 07-40384
The influence of grain orientation on penetration, retention, and leaching of CCA (C) was tested on small samples of sapwood and heartwood of Cupressus lusitanica and Pinus patula. Samples measuring 50mm x 50mm, and 200mm in the longitudinal axis were sealed to expose only transverse, or radial, or tangential faces, pressure treated with 6% CCA (C), and penetration, retention and leaching of the ...
R Venkatasamy