Your search resulted in 43 documents. Displaying 25 entries per page.
A review of the configuration of bordered pits to stimulate the fluid flow
2005 - IRG/WP 05-40315
As the bordered pits have generally been thought to have an influence on the refractory nature of softwoods, structural behaviour of this conducting pathways is discussed according to the published literature. Various theories on the role of bordered pits to axial flow are expounded in respect to preservative treatment. Pit aspiration is also reviewed....
I Usta
Natural durability transfer from sawmill residues of white cypress (Callitris glaucophylla). - Part 3: Full penetration of the refractory sapwood of white cypress
2000 - IRG/WP 00-40167
The heartwood of white cypress, Callitris glaucophylla, is renowned for its termite resistance and durability against decay. The sapwood, which can represent up to 30% of log volume, is non-durable and refractory to conventional preservative treatment. Previous work ascribes the lack of permeability to oily deposits within tracheids and ray cells. Environmental scanning electron microscopy was use...
M J Kennedy, L M Stephens, M A Powell
Report of the meetings of the Refractory Timbers Sub-group, Rotorua, New Zealand, 15 & 17 May 1990
1990 - IRG/WP 3637
R J Murphy
Investigation into the heterogeneous nature of the impregnability of some poplar hybrids
1995 - IRG/WP 95-40052
Retention figures of some poplar hybrids are very heterogeneous when pressure impregnated. This makes it hard to prescribe impregnation processes for fast grown poplars that make it suitable for higher hazard uses. In order to gain fundamental knowledge in their variability in impregnation properties two trees were selected for a detailed investigation. Both trees originate from the same plantatio...
J Van Acker, M Stevens
Report of the meeting of the refractory timbers sub-group, Lappeenranta, Finland on 25 May 1989
1989 - IRG/WP 3561
The first meeting of this sub-group took place on Thursday 25 May and considered the following agenda: 1) Papers presented to the meeting "Performance of treated spruce in Canadian field test sites" by J.P.Hösli and E.E.Doyle, IRG/WP/3506 and "Performance of CCA treated spruce and pine in unsterilized soil" by A.J.Nurmi. 2) Future work areas for the sub-group 3) Membership of the sub-group 4) Cir...
R J Murphy
A behaviour of CCA penetration of fir (Abies bornmulleriana Mattf.) at different ramp times and constant vacuum/pressure applications
2006 - IRG/WP 06-40346
A behaviour of CCA penetration of Bornmulleriana fir (Abies bornmulleriana Mattf.) at different ramp times and constant vacuum/pressure applications was illustrated for the main flow directions by the experimental pictures....
I Usta, R Despot, M Hasan
The chemical nature of bis(tributyltin) oxide in Pinus sylvestris sapwood
1989 - IRG/WP 3508
Tributyltin compounds have been used for many years as wood preservatives. This study has provided, for the first time, an explanation for the previously reported dealkylation and/or volatilisation of the tributyltin species in, and from, Scots pine (Pinus sylvestris) sapwood. Thus, 119 Sn nuclear magnetic resonance studies have shown that, on impregnation into this timber, bis(tributyltin) oxide ...
S J Blunden, R Hill
An inclination incising technique for the preservative treatment of refractory timbers
1991 - IRG/WP 3664
An inclination incising technique for preservative treatment of refractory timbers was examined by changing cutting angle to the longitudinal direction of test specimen and by using different types of knife edge. Incised wood were impregnated locally into incisions with CCA solution by the specified local pressure process. Width and length of penetration areas of CCA solution were measured on long...
Y Nakamura, K Nishimoto
A technique for determinging the efficacy of wood preservatives for partially treated timber
1988 - IRG/WP 2322
A technique is described for determining the efficacy of wood preservatives either for certain wood species where a full penetration cannot be achieved by normal vacuum-pressure methods or for more permeable species to look at efficacy of treated zone in preventing decay of an untreated core. Both sapwood and heartwood planks of spruce (Picea abies) and pine (Pinus sylvestris) were treated by CCA ...
A J Nurmi
The possible role of mobile CCA components in preventing spore germination in checked surfaces, in treated wood exposed above ground
2001 - IRG/WP 01-30263
Untreated check surfaces are often exposed in CCA-treated lumber of refractory species used above ground since, during weathering, some checks develop beyond the preservative penetrated zone. However, decay is seldom observed in these checks even after many years of exposure. It is hypothesized that minor amounts of mobile CCA preservative components redistribute during weathering into checks, and...
S Choi, J N R Ruddick, P I Morris
A prototypical needle-incisor for refractory timber
1995 - IRG/WP 95-40041
A needle-incisor was manufactured for trial. This machine has an incising mechanism that a set of needles held by a rotary plate incises timber which is moved toward the front simultaneously, and then another set of needles incises a new part of the timber. Timber is incised by recycling the process. Timber incised of 4400 incisons/m² with the depth of 56 mm by 2.8 mm-diameter needles on all the ...
A Yakuwa, H Endoh, M Mori, S Doi
The field performance of CCA-C treated sawn refractory softwoods from North America
1997 - IRG/WP 97-40085
Approximately 15% of the total volume of wood treated in the United States consists of difficult to treat softwoods known as "refractory softwoods". The long term positive performance record of CCA treated sawn material is based upon the testing of yellow pine sapwood stakes with only limited field data available for sawn refractory softwoods. As a result, the existing North American wood preserva...
M J Richards, W S McNamara
Influence of clonal variability on the impregnability of poplar hybrids. (+ correction document of 23 April 1990)
1990 - IRG/WP 3614
The new Western European poplar clones (Populus nigra x deltoides and Populus trichocarpa x deltoides) were compared with the reference clone 'Robusta' and some old hybrids. Samples (5x5x50 cm³) with pure tangential/radial surfaces were sawn, including the transition zone between heartwood and sapwood. Treatment by a standard vacuum-pressure impregnation cycle with CCA showed a ...
J Van Acker Van, M Stevens, C De Haas
The dry rot fungus (Serpula lacrymans) in nature and its history of introduction into buildings
1999 - IRG/WP 99-10300
For many years the True dry rot fungus (Serpula lacrymans (Wulf.: Fr.)Schroet.) has exclusively been found in buildings. That is why it is called the True dry rot fungus. The origin of the fungus has always been a mystery, but a wild ancestor must have occured. In the literature there is some information about finds of Serpula lacrymans in nature, however it is difficult to distinguish it from the...
J Bech-Andersen, S A Elborne
A review of incising as a means of improving treatment of sawnwood
1994 - IRG/WP 94-40019
The use of incising, perforation of the wood surface, is increased because of the need to treat refractory wood species. This paper reviews the development of incising and shows how the required incising patterns can be determined and specified. Most of the development has been in the area of toothed-roller incisors because of their rapid throughput. Needle, Laser, drill and water jet incisors hav...
P I Morris, J J Morrell, J N R Ruddick
Treatment of refractory timbers
1993 - IRG/WP 93-40001
Worldover crisis of wood is being felt due to the global environmental problems. Wood preservation technology plays a good role in curtailing the demands of wood for replacement by prolonging the service life of the timber and thus indirectly helps in saving the environment. Some species of timbers which could not be treated to the desired level by virtue of their refractory nature by any of the c...
I Dev, S Kumar
Observations on preservative penetration in poplar
1991 - IRG/WP 3662
In the course of studies on the CCA treatment and durability of poplar timber a zone of refractory wood at the sapwood/heartwood boundary was observed. Further studies were conducted to investigate the causes of this refractory behaviour. The initial results have suggested that the presence of lipid storage products in the ray tissue may lead to impermeability, either by directly blocking pits or ...
R J Murphy, S U Din, M J Stone
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 nature of osmiophilic particles and their distribution during different stages of brown and white rot decay
1983 - IRG/WP 1213
The distribution of osmiophilic particles during the course of brown and white rot decay was investigated by applying transmission electron microscopic (TEM) methods. It was found that it correlates with the brown and white rot pattern.The osmiophilic particles are produced by the fungus and are supposed to be wood rotting enzymes....
K Messner, H Stachelberger
On the nature of the tertiary wall in wood cells. Summary of lecture given at 9th Annual Meeting, Noordwijk-aan-Zee, Holland
1977 - IRG/WP 169
During recent discussions on the possible causes of failure of treated hardwood species by soft rot fungi, the uneven micro distribution of toxic components was found to be of importance; this might be attributed to a restricted diffusion of the preservative from the cell lumina into the cell wall.·In this context, the nature of the tertiary wall as the inner lining of wood cells merits special a...
W Liese
The antigenic nature of Serpula lacrymans
1991 - IRG/WP 1492
The molecular nature of Serpula lacrymans has been extensively analysed by SDS-PAGE and distinctive banding patterns have been demonstrated. To develop simpler methods for identification of the organism an immunological analysis of a variety of isolates of both Serpula lacrymans and a number of other wood decay basidiomycetes has been undertaken. Results indicate unique antigenic profiles for Serp...
A Vigrow, H Glancy, J W Palfreyman, B King
Specifying preservative-treated resistant timber: Conforming to European Standards
2001 - IRG/WP 01-20235
The most common construction timbers used in the UK are of low natural durability and, generally, resistant to preservative treatment. These include species of spruce, hemlock and fir. However, their characteristically limited and non-uniform uptake of preservatives may still confer sufficient protection to give satisfactory durability performance in terms of biological resistance. This paper desc...
E D Suttie, A F Bravery, T B Dearling
"Refractory" is a relative term. Incised alpine fir is treatable
1991 - IRG/WP 3670
While certain wood species carry a reputation for being 'treatable' this normally refers to the sapwood. For most Canadian species, heartwood penetration is the major determinant of whether treatment meets Canadian, USA and Japanese standards and in this respect alpine fir turns out to be a treatable species. Alpine fir is the fir component of the Western Canadian spruce-pine-fir...
P I Morris
Application of oscillating pressure to improve treatability of refractory species
1987 - IRG/WP 3449
Under practical conditions a minimum moisture content of 80% demande by the German quality standard RAL-RG 411 can not be guaranteed throughout the year. Storage of logs with bark prolonges the drying process; a storage without bark must be avoided. A sufficient penetration according the standard can be achieved at least with a moisture content of 60%, optimal conditions may prevail between 100% a...
R-D Peek
Influence of the nature of the substrate and the method of inoculation on the degradative activity of soft rot fungi
1998 - IRG/WP 98-20133
The European Standard (ENV-807) determines the threshold of effectiveness of wood preservatives against the action of soft rot Ascomycetes fungi. Its application in the treatment of wood used in the hazard class 4 does not always offer repeatable results, which could be expected in an experimental norm.
For this reason, in this paper, we have evaluated the diverse variables that might influence t...
M T De Troya, A M Navarrete, F Rubio, J Jiménez, D Muñoz-Mingarro, C Rodríguez-Borrajo, F Llinares, M Yuste