Your search resulted in 481 documents. Displaying 25 entries per page.
Soft rot studies on CCA treated eucalypt power transmission poles
1981 - IRG/WP 1132
Initial results found for sixty CCA treated eucalypt poles, from a soft-rot survey are discussed. Retentions of CCA within above and below ground pole samples were variable. The variation was attributed mostly to biodegradation and effect of soil environment, rather than leaching. Bacterial decay was found in many poles and was severe in some cases. Although found in the presence of soft-rot decay...
L E Leightley
Identification of terminal structures in cellulose degraded by the brown-rot fungus Postia placenta
1989 - IRG/WP 1389
To gain insight into the biochemical mechanism employed by brown-rot fungi to depolymerize cellulose, we identified the end-groups of chemically pure cellulose that had been depolymerized by the brown-rot fungus, Postia placenta. The depolymerized cellulose was acid hydrolyzed and the anion fractions isolated by ion chromatography. Sugar acids were identified by gas chromatographic and mass spectr...
T K Kirk, T L Highley, R E Ibach, M D Mozuch
Practical consequences of the clarification of the chemical mechanism of CCA fixation to wood
1983 - IRG/WP 3220
Practical consequences derived from the chemical investigation of the mechanism of fixation of CCA to the wood constituents are discussed. Among these, formulas for the calculation of the time of hexavalent chrome fixation are presented. Furthermore, three parameters are shown to be important to the long-term effectiveness of CCA-treated timber: (i) the temperature of treatment, (ii) the initial p...
A Pizzi
Changed permeability and surface properties of hornbeam wood due to its degradation by erosive strain of Phanerochaete chrysosporium
2004 - IRG/WP 04-40290
Specimens of hornbeam wood were submitted to a medium-term degradations by erosive fungus Phanerochaete chrysosporium. Biodegradations of specimens resulted in their apparent structural alterations, changes in permeability and increased intensity of interactions with polar liquids. Modified physical properties of biodegraded wood may significantly influence its penetration with polar media and che...
R Solár, S Kurjatko, L Reinprecht, M Mamon, V Vacek
Natural durability transfer from sawmill residues of white cypress (Callitris glaucophylla). - Part 2: Laboratory fungal bioassays
2000 - IRG/WP 00-20204
Extracts from sawmill residues of the naturally durable white cypress, Callitris glaucophylla were tested for fungicidal activity in a series of laboratory bioassays. The effects of different extraction solvents, techniques and sources of material on the biocidal efficacy of the resultant extracts were evaluated. Soil jar decay tests were used initially however, contractual time constraints necess...
M A Powell, L M Stephens, L Francis, M J Kennedy
The efficacy of remedial treatments for controlling fungal decay in window millwork used in the United States
1987 - IRG/WP 3432
Conventional window millwork was subjected to basidiomycete decay by inoculation and sampled for active growth of the decay fungus before and eight months after remedial preservative treatment with fused disodium octaborate rods (IMPEL) at boric acid levels of 1.5 and 4.0 kg/m³ or liquid bifluoride injections (IMPROSOL) at 1 kg/m³. The elimination of decay fungus after remedial treatment was nea...
M G Dietz, E L Schmidt
Enzyme systems of bacterial isolates from ponded logs - Potentials of pectin and/or starch degradation
2000 - IRG/WP 00-10378
This paper deals with the degradation potentials of wood constituents by the bacterial isolates from ponded logs. The potentials to degrade pectin as a constituent of pit-tori as well as starch existing in ray parenchyma cells in the areas of sap- and transition wood with the isolates were examined. The pectinase activity was investigated by means of the degradation degree of a carrot strip used a...
S Doi, S Ohta
Fungal Stain Development in Canadian Hardwood Logs
2004 - IRG/WP 04-10505
In most sawmills around the world, trees are harvested into logs and stored in the forest or in a log yard for a period of time before being sawn into lumber. These logs may be attacked by various pigmented fungi, which results in staining of the wood. Since hardwood species are used to a great extent in furniture manufacturing and in the making of other valuable wood products, the reduction of wo...
Dian-Qing Yang, M-C Bisson
Moisture uptake and volumetric swelling as probable factors also affecting leaching in CCA-treated wood. A preliminary study of treated Eucalyptus saligna sapwood
2003 - IRG/WP 03-30318
IRG/WP 03-30318
A number of factors affecting leaching of CCA from treated wood have been variously investigated and discussed. However, the possible effects of moisture movement in treated timbers on leaching have not received attention yet. The present study examines and compares moisture uptake and volumetric swelling in CCA-treated and untreated sapwood of Eucalyptus saligna, and tries to establish a correl...
R Venkatasamy
The effect of hemicellulose degradation on the mechanical properties of wood during brown rot decay
2001 - IRG/WP 01-20219
Incipient decay of wood by brown rot fungi causes measurable strength losses in wood before measurable weight loss occurs. Previous studies have shown that the high levels of strength loss that occur during incipient brown rot decay may be related to loss in hemicellulose. This paper investigates the effect of decay on hemicellulose composition and the relationship to the mechanical properties of ...
S F Curling, C A Clausen, J E Winandy
Susceptibility of CCB treated wood to fungal colonization
2003 - IRG/WP 03-10492
CCB treated wood is generally resistant to all wood decay fungi. However, like CCA impregnated wood, susceptibility of CCB treated wood to copper tolerant fungi have been observed. The ability of various brown rot fungal hyphae to penetrate and overgrow the wood samples was investigated. Samples made of Norway spruce (Picea abies) were impregnated with 5 % CCB solution according to the EN 113 proc...
F Pohleven, U Andoljsek, P Karabegovic, C Tavzes, S A Amartey, M Humar
Chemical and biological studies of organotin treated and painted wood stakes after outdoor exposure
1987 - IRG/WP 3419
Organotin based wood preservatives containing tributyltin oxide (TBTO) or tributyltin naphthenate (TBTN) are used in Sweden mainly for double-vacuum treatments of window joinery of Pinus sylvestris. After impregnation the joinery is painted or stained in different colours. To evaluate this effect (different colours on the degree of degradation of TBTO and TBTN, effected by different temperatures i...
M-L Edlund, B Henningsson
Evaluation of fungal remediation of creosote treated wood
1998 - IRG/WP 98-50101-25
Biotechnological remediation of creosote treated wood may be of interest in connection with novel recycling processes. White rot fungi and/or their ligninolytic enzyme systems are supposed to be valuable tools for such processes. This paper reports about results achieved when creosoted wood was treated in solid substrate fermentation with selected white rot fungi after different extraction procedu...
K Messner, S Böhmer
Evidence for wood cell wall degradation by the blue stain fungus Botryodiplodia theobromae Pat
1994 - IRG/WP 94-10077
Botryodiplodia theobromae Pat., a world wide ubiquitous polyfagus sapstain fungus, was found able to destroy the cell walls of birch fibres (Betula verrucosa Ehrh.) but not Caribbean (Pinus caribaea var. hondurensis Barr. and Golf.) and Scots pine (Pinus sylvestris L.) tracheids. The fungus caused characteristic erosion of fibre cell walls similar to soft rot type 2; destruction of the S1 - S2 int...
O Encinas, G F Daniel
An evaluation of chemical treatments for the protection of radiata pine logs from fungal degrade
1986 - IRG/WP 3377
Busan 30, Busan 1009, Mitrol PQ375. and sodium pentachlorophenoxide (NaPCP) plus have been evaluated as antisapstain treatments for the long-term protection of debarked radiata pine logs. After 3 months' winter-spring storage, treated debarked logs had less surface and internal sapstain than 'control' logs. After 6 months' storage all logs had internal sapstain ...
J A Drysdale, M E Hedley, J A Butcher
Étude in vitro de la colonisation et de la dégradation structurale du bois d'aubier de Pin sylvestre par la Mérule: Serpula lacrymans Schum. ex Fr. S. F. Gray
1979 - IRG/WP 198
The degradation of Scots pine sapwood cell walls by Serpula lacrymans, a brown rot fungus, is observed after various periods of exposure from two weeks to twelve weeks. The observation by microscopy shows that the hyphae of Serpula rapidly invade the wood tissues as cell wall degradation starts. That deterioration is not gradual, it is observed to be very irregular as well within the whole of the ...
D Dirol
Effect of mobile fungicides on fungal pre-infection in radiata pine billets.
1999 - IRG/WP 99-30191
In New Zealand, fungal infection of logs begins directly after felling and whilst severe degrade can be prevented if antisapstain-treated within 24 hours, such short turn-around times of logs are not always practicable. However, conventional antisapstain formulations in use only provide an envelope of protection on the log surface but are unable to control pre-infections below the surface. The obj...
D R Eden, T Singh, B Kreber
Moisture requirements and wood degradation of pine and spruce wood by some Basidiomycetes-fungi
1989 - IRG/WP 1406
The minimum moisture requirements for the growth of the brown rot fungi, Coniophora puteana, Gloeophyllum trabeum and Serpula lacrymans were near or above the fibre saturation point of pine and spruce, sap and heartwood, during 160 days incubation according to the standard method EN 113. The moisture of wood for the optimum growth of Coniophora puteana and Serpula lacrymans was about 35-80% and fo...
H Viitanen, A-C Ritschkoff
Correlation between changes in colour and chemical composition during photo-degradation of wood surfaces
2005 - IRG/WP 05-40301
Changes in colour of wood (yellowing) during photo degradation or weathering reflect chemical changes in wood. Therefore, the relationship between changes in chemical composition and CIELAB colour parameters is very important to characterize photodegradation of lignocellulosic surfaces. In this study, the changes in chemical composition and yellowing due to photo-degradation was studied by expos...
K K Pandey
Improvement of some technological and biological properties of poplar wood by impregnation with aqueous macromolecular compounds
1992 - IRG/WP 92-3721
Poplars (Populus spp) belong to the most important tree species in afforestation programs of the Netherlands. Due to their rapid growth, the wood quality is usually low. Therefore, studies were performed to elucidate whether some technological properties and the resistance against fungal attack could be improved by impregnation with water-soluble resins. The results showed that swelling and shrink...
R D Peek, H Militz, J J Kettenis
Using image analysis to rate wood stain trials
1993 - IRG/WP 93-10034
Assessing the extent of fungal discoloration on wood during laboratory trials is a subjective process which provides an opportunity for considerable variation between individual evaluators of specimens. The development of reliable systems for automatically assessing discoloration would minimize evaluator bias and permit comparisons between results from different laboratories. The use of image anal...
C M Sexton, A G Maristany,C C Brunner, J J Morrell
Fungal-termite associations in the natural resistance of selected eucalypt timbers
1978 - IRG/WP 173
Butt billets of Eucalyptus regnans F. Muell., Eucalyptus grandis W. Hill ex Maiden, and Eucalyptus camaldulensis Dehnh., showing no visible signs of decay, were examined for the presence of fungi in outer, middle and inner heartwood. Fungi obtained in pure culture were characterized. Eucalyptus regnans yielded Cytospora eucalypticola van der Westhuizen, Trichoderma harzianum Rifai and Penicillium ...
D B A Ruyooka
Accelerated decay tests to investigate postulated effects of tannins on CCA efficacy in wood
1988 - IRG/WP 3497
Five groups of blocks (10 x 10 x 5 mm³) viz., Pinus patula, Pinus patula impregnated to 4% (w/w) tannin; Eucalyptus grandis, Eucalyptus grandis with natural tannins extracted; and extracted Eucalyptus grandis with tannins returned as above; were prepared. Blocks from each group were then treated to 0, 5, 10 and 15 kg/m³ CCA and challenged in four 15-week decay tests, viz., soil burial, and expos...
U L Scherer, A A W Baecker
Effect of angle of exposure on degradation of radiata pine during weathering trials
1988 - IRG/WP 2301
The importance of angle of exposure on the degree of weathering of materials has not been adequately resolved. In conventional tests, specimens are exposed at an angle of 45° facing the equator, but more recently experiments on polymeric materials have suggested that an angle of 0° may be preferable since this angle maximises levels of received ultra-violet radiation. In this paper the degradati...
P D Evans
Preliminary studies of the decay mechanism of some brown-rot fungi
1989 - IRG/WP 1402
The importance of the enzymatic degradation of hemicellulose and cellulose by brown-rot fungi is still under discussion. Endo-ß-1,4-xylanase and endoglucanase activities of Coniophora puteana and Poria placenta cultures were measured by the increase in reducing groups. Enzymes were produced in liquid and solid sawdust based culture media. Enzyme activities were measured in two, four and eight wee...
A-C Ritschkoff, H Viitanen