Your search resulted in 318 documents. Displaying 25 entries per page.
Studies of the ray parenchyma cell ends on the radial flow of Sitka spruce (Picea sitchensis)
2000 - IRG/WP 00-40164
It is widely accepted that either ray tracheids or ray parenchyma cells offer the major flow pathways radially for the impregnation of softwood with preservative chemicals. It is now generally recognised that, if radial flow does occur through ray parenchyma cells, the cross-field pits play a dominating role for the liquid movement in the radial direction. In this case, the radial flow of fluid is...
I Usta
The degradation of wood by metal fastenings and fittings
1972 - IRG/WP 302
As well as the hazards of biological decay, timber used in boat building is subject to the effects of chemical decay associated with the corrosion of metallic fastenings. The title has been deliberately chosen to emphasize that in wooden construction the troubles are not just those of corrosion of the fastenings, but also the destructive secondary effects on the wood caused by the products of the ...
L C Pinion
Bacteria are important degraders of cooling tower timbers: New Zealand experience
1995 - IRG/WP 95-10128
Microscopic examinations of CCA-treated Pinus radiata timbers in industrial cooling towers in New Zealand showed bacteria and soft rot fungi to be primarily responsible for the decay of these timbers. Of these micro-organisms, erosion bacteria appeared to be most widespread, attacking wood cell walls independently as well as together with tunnelling bacteria and soft rot fungi. Tunnelling bacteria...
A P Singh, R N Wakeling
New approaches to practical evaluation method of bio-degradation of wooden construction - Non-destructive detection of defects using radar technique
2000 - IRG/WP 00-20214
There have been a number of researches and developments on the techniques and apparatus for the nondestructive evaluation of the biological deterioration in wood and wooden constructions, such as decay or insect attack in house, public buildings or in historically important architectures. As for the detection of the decay in wood, techniques using sound in audible or in ultrasonic frequency ranges...
Y Fujii, Y Komatsu, Y Yanase, S Okumura, Y Imamura, M Tarumi, H Takiuchi, A Inai
A note on te seasoning, preservative treatment and suitability of debdaru (Polyalthia longifolia Benth & Hooker.) for poles
1995 - IRG/WP 95-40056
The main work is to determining the suitability of Debdaru (Polyalthia longifolia Benth.) as poles from Government and Village forests are investigated. The poles of Debdaru are easily treatable with CCA preservative by full-cell pressure method, but difficult to dry (air & kiln). Proper quality control must be maintain from procurement to treatment, specially during physical selection & d...
G N M Ilias, M D Rokib-ul-Hafiz
Lignin degradation by a non-enzymatic system supposed to be active in white rot fungi
2000 - IRG/WP 00-10340
Electron microscopic investigations have shown that ligninolytic enzymes of white-rot fungi are only able to penetrate the wood cell wall in late stages of degradation. Thus, the selective degradation of lignin of certain white-rot fungi can only be explained on the basis of a low molecular weight, highly diffusible system. A system, consisting of copper, a coordination compound and either H2O2 or...
P Lamaipis, W Gindl, T Watanabe, K Messner
Aspects of leaching
1976 - IRG/WP 267
With respect to Document No: IRG/WP/246, and the recommendation that an economic leaching test can be based on a non-changing volume of water (500 ml/block), I would like to relate our experiences with this suggestion. Following 14 days of continuous immersion in de-ionized water it was found that blocks treated with moderate and above concentrations of a preservative gave no problems, but those b...
R S Smith
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
Permanence of permethrin and bifenthrin in framing timbers subjected to hazard class 3 exposure
2005 - IRG/WP 05-30383
End-sealed Pinus radiata specimens measuring 235 x 90 x 35 mm were treated using a modified Lowry schedule with permethrin or bifenthrin in white spirit to Hazard Class 2 (H2) retentions. After conditioning, the specimens were exposed at 45o on north facing racks near Melbourne (Australia). Samples of the specimens were taken before installation, and after three and six months exposure. Analyses o...
A C Hunt, D G Humphrey, R Wearne, L J Cookson
Aspects of the fungal degradation of quaternary ammonium compounds in liquid culture
1997 - IRG/WP 97-30160
Didecyldimethylammonium chloride (DDAC) is a quaternary ammonium compound (QAC) that has found use as an anti-sapstain preservative for the transportation of softwood lumber from Canada to overseas markets. However, its use is limited by the knowledge that certain mould fungi seem capable of degrading it. The aim of this research was to gain knowledge about the fungal degradation of DDAC. The effe...
J W Dubois, J N R Ruddick
Notes on a wood preservation industry in Medan, North Sumatera, Indonesia
1987 - IRG/WP 3405
This paper deals with a descriptive account on the development of a wood preservation industry in Medan, North Sumatera (Indonesia). The industry was established in 1974 when the State Owned Electicity Corporation decided to use wooden power poles for their distribution network in North Sumatera province. However, the use of wooden power poles was discontinued in 1981, so as the preservation indus...
N Supriana, A Murad
Respiration measurement of dry-rot
1995 - IRG/WP 95-10095
Methods for measuring the production of carbondioxide from wood infected with the dry-rot fungus were evaluated. By enclosing whole wood blocks and measuring the concentration of gas in the headspace by gas chromatography, an exponential increase in the concentration of CO2 was observed for at least 2 months. This technique could therefore present a method for evaluating various treatments of dry-...
L Toft
The effect of water storage on the cell-structure of Sitka spruce (Picea sitchensis) with reference to its permeability and preservation
1970 - IRG/WP III 3A
Commercial treatment trials with full sized transmission poles have shown that water storage considerably improves the permeability of Sitka and Norway spruce. These results were confirmed by laboratory measurements which showed that in the sapwood of ponded Sitka spruce there is a vast improvement in permeability in all three grain directions. Heartwood permeability does not seem to be affected t...
J A Dunleavy, A J McQuire
Alternative technologies for wood wastes recycling - Part A: Supercritical extraction of PAH compounds from wood wastes
1998 - IRG/WP 98-50101-18 a
Alternative technologies have been investigated to detoxify treated wood. Two classes of organic compounds are studied. Creosote-treated wood are classified in France as dangerous wood wastes. A conventional incineration could be provided for these wood wastes but the cost of this elimination could be very high (> 2000 FFR/ton). For these reasons, we have tested two kinds of new processes as al...
L Schrive, C Perre, G Labat
Extracellular substance from the white rot basidiomycete Irpex lacteus involved in wood degradation
1992 - IRG/WP 92-1571
Cellulases, phenol oxidase, and a substance that both produced and reduced H2O2 were isolated from cultures containing wood or glucose on which the white-rot fungus Irpex lacteus was growing. The rate of wood degradation by the fungus with different amounts of glucose in the medium was measured. More of the substance that produced and reduced H2O2 was found extracellularly in cultures containing w...
H Tanaka, T Hirano, G Fuse, A Enoki
Relationship between degradation of wood, cellulose or lignin-related compounds and production of hydroxyl radical or accumulation of oxalic acid in cultures of brown-rot fungi
1994 - IRG/WP 94-10062
The degradation activities of brown rot fungi against wood, cellulose, and lignin-related compounds were measured in cultures containing glucose or wood as a carbon source. Also the activities of one-electron oxidation and hydroxyl radical production and the amount of oxalic acid present in the cultures were measured. The degradation activities of the fungi against wood, crystalline cellulose and ...
S Itakura, T Hirano, H Tanaka, A Enoki
The effect of rate of pressure application on preservative uptake along and across the grain of fir (Abies bornmulleriana Mattf.) at different ramp and constant pressure times
2004 - IRG/WP 04-20292
This study was particularly design to determine the preservative uptake at different ramp (rate of increase in pressure) and constant pressure times on longitudinal, tangential and radial penetrations of fir (Abies bornmulleriana Mattf.) which grown indigeneously in Turkey. The samples of 2 cm cubes of kiln-dried wood (nominated to 12% moisture content) were treated at different ramp times varied ...
I Usta
The role of oxidation in wood degradation by brown-rot fung
1992 - IRG/WP 92-1562
Brown-rot fungi are suggested to degrade cellulose by oxidation with hydrogen radicalsformed eg. in the conversion of hydrogen peroxide in the Fenton type reactions. The stuctural changes in the holocellulose in wood induced by Fenton's reaction on wood components are very similar to those caused by brown-rot fungi. In this work the effect of the Fenton reaction on wood components was stu...
A-C Ritschkoff, J Pere, J Buchert, L Viikari
Study of the degradation caused by micro-organisms in Pinus sp. waterlogged wood
1989 - IRG/WP 1411
So far, the different Centers are trying the restoration and the conservation of wood structures, coming from subaquatic archeological deposits, with interest from the historic - artistic point of view. The main objective of this paper has been the determination of the decay level of Pinus sp. wood coming from a roman ship (approximately 2000 years old), where we have analyzed their physical prope...
M T De Troya, M C Escorial, J Garcia, A Cabanas
Effect of some resin treatments on fungal degradation reactions
1999 - IRG/WP 99-10318
The effect of impregnation of wood with vegetable oil, tall oil and two water soluble on fungal degradation reactions was assessed by hydrolysis and enzyme activity measurements. The experiments were carried out by using isolated enzyme preparations and a living brown-rot fungus Poria placenta. The results indicate that the inhibitory effect of treatments was clearly directec towards the enzymatic...
A-C Ritschkoff, M Rättö, A J Nurmi, H Kokko, A O Rapp, H Militz
Resistance of acetylated wood to biological degradation. Evaluation of field test
1997 - IRG/WP 97-30139
Acetylated wood samples were tested in ground contact (stake test) at two test fields, one in Simlångsdalen, Sweden, and one in Viikki, Finland, according to European standard EN 252. The test samples were inspected annually and their condition was compared with that of untreated controls and of samples treated with two reference CCA preservatives. The use of untreated controls and preservative t...
P Larsson Brelid, R Simonson, Ö Bergman
Cytoplasmic and extracellular localization of manganese II dependent peroxidase(s) in white rot fungi during degradation of woody materials
1989 - IRG/WP 1416
The manner by which lignin is degraded in-situ in natural substrates by white rot fungi still remains a controversial issue particularly the distribution and role(s) played by lignin degrading enzymes (i.e. manganese II peroxidase and lignin peroxidase). In the present study, use was made of anti-manganese II peroxidase and immunolabelling techniques in conjunction with transmission electron micro...
G F Daniel, B Pettersson, T Nilsson, J Volc
Differences in pH, electrical resistance, cation composition and NIR spectra of red spruce wood during early stages of brown rot degradation
2002 - IRG/WP 02-10449
Red spruce sapwood was exposed to degradation by the brown rot fungi Coniophora puteana, Postia placenta, Gloeophyllum trabeum and Serpula lacrymans for 0, 1, 2 or 3 weeks using a modified soil block assay design. Average weight losses over time ranged from 0-8.9% during this time period. Detectable changes in pH, electrical resistance and cation compostion were observed in the wood as early as 1 ...
J Jellison, S Kelley, B Goodell, D Hui, A Ostrofsky
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
Bacterial degradation of Pinus radiata compression wood
1996 - IRG/WP 96-10153
An inspection of twelve year old, CCA-treated Pinus radiata wood from an industrial cooling tower showed extensive surface decay of wood. Electron microscopic examination of decaying compression wood indicated that compression wood cells were attacked exclusively by bacteria, which were of erosion and tunnelling types. As compared to the normal wood, compression wood appeared to be more resistance...
A P Singh, R N Wakeling