Your search resulted in 263 documents. Displaying 25 entries per page.
Models of the critical time of humidity and temperature conditions for the development of mould fungi in pine and spruce sapwood
1995 - IRG/WP 95-20066
Regression models of the time factor for the growth of mould fungi in pine and spruce sapwood are studied. The first group of models are based on the results of exposures of mould fungi in static humidity and temperature conditions indicating the time for the start of mould growth in wood. The second group of models are based on the exposures of mould fungi in fluctuating or alternating humidity a...
H Viitanen
The effect of pretreatments on the impregnation of air-dried sawn Belgian spruce
1988 - IRG/WP 3490
In general the impregnation of airdried spruce results in a variable treatment and limited penetration. This is the result of pit aspiration that occurs during drying of the spruce sapwood and heartwood. Spruce timber is becoming of greater importance in Belgium and hence research for better treatment of this vulnerable wood species is needed. Squared airdried timber of different dimensions were e...
J Van Acker, M Stevens
Durability of heat-treated wood
1999 - IRG/WP 99-40145
Heat-treated wood from the French process were laboratory tested against decay using agar block test and a modified soil block test. Water absorption, bending strength, lignin content and acid number were also determined to evaluate the effect of heat treatment. Heat treated samples exhibit a higher lignin content and a lower acid number compared to untreated control indicating the degradation of ...
D P Kamdem, A Pizzi, R Guyonnet, A Jermannaud
Ability of chloropicrin, Vorlex, or methylisothiocyante to prevent marine borer attack of Douglas fir piling
1989 - IRG/WP 4153
The preservative-treated shell around Douglas-fir piling is an excellent barrier to attack by marine borers; however, damage to this shell can permit marine borer attack. The feasibility of using fumigants to enhance piling performance was examined by exposing fumigant-treated Douglas-fir sections in marine waters off Newport, OR, or Port Hueneme, CA. The piling were inspected annually and increme...
M A Newbill, J J Morrell
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
Supercritical fluid impregnation of Douglas-fir heartwood with cyproconazole using temperature induced deposition
2003 - IRG/WP 03-40259
A limited understanding of the fundamental aspects of supercritical fluid (SCF) impregnation in wood remains an obstacle to the development of this technology. Developing a better understanding of the effects of various process parameters on treatment results would facilitate more rational development of SCF impregnation. In this project, the effect of treating period and specimen length on su...
Sung-Mo Kang, J J Morrell
Supercritical fluid treatment: Effects on bending strength of white spruce heartwood
1993 - IRG/WP 93-20008
The effects of supercritical carbon dioxide on wood strength were evaluated using white spruce heartwood, a species known to be especially susceptible to collapse during exposure to higher pressures. The effects of pressures of 2000 or 3600 psig and temperatures of 40 or 80°C were evaluated using 30 or 60 minute exposure periods. No significant differences were noted in modulus of rupture or modu...
S M Smith, J J Morrell, E Sahle-Demessie, K L Levien
Effect of climate, species, preservative concentration and water repellent on leaching from CCA-treated lumber exposed above ground
2001 - IRG/WP 01-50178
Few studies have examined leaching of chromated copper arsenate (CCA) from treated wood in above ground exposures due to the assumption that leaching is less severe compared to wood in continuous contact with soil or water. However, a significant portion of CCA treated wood is used for above ground applications, exposing considerable volumes of the preservative to precipitation and potential leach...
J L Taylor, P A Cooper
Kerfing reduces checking in ACA-treated western white spruce poles
1988 - IRG/WP 3477
Western white spruce poles, pressure treated with pentachlorophenol and ammoniacal copper arsenate (ACA) were installed in the Westham Island test site. The pentachlorophenol treated poles were unkerfed, while both unkerfed and kerfed ACA poles were placed in test. The checking and kerf width and depth were recorded at the time of installation. After ten years of weathering the checking characteri...
J N R Ruddick
The treatment of Douglas fir fence posts: specification and compliance using new European standards
1999 - IRG/WP 99-20178
New European standards for the preservative pre-treatment of timber require the results of the treatment process to be specified and subsequently verified by examination of the treated timber for penetration and retention of the preservative. For penetration, the standards are restrictive in that there are only a limited number of options available to the specifier. Thus for ground contact service...
R J Orsler, H Derbyshire
Investigation of the suitability of silver fir (Abies alba Mill.) for thermal modification
2004 - IRG/WP 04-40275
In this study the suitability of silver fir (Abies alba Mill.) was examined for thermal modification. Comparative experimental investigations were performed with silver fir and Norway spruce (Picea abies Karst.) after thermal treatments. Besides properties, which characterize the quality of heat treatments, like dimensional stability and resistance against fungal attack, strength properties of the...
C Brischke, A O Rapp
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
Cell wall microdistribution of chloropicrin and methylisothiocyanate in treated spruce
1989 - IRG/WP 3548
Chloropicrin and methylisothiocyanate (MIT) residues were observed using SEM/EDXA and TEM/EDXA in treated spruce wafers that had been exposed to the vapors of the two fumigant preservatives. Chlorinated residues from chloropicrin were found throughout the wood cell wall, even in acetone extracted material. The residues were most heavily concentrated in extractive materials in the rays, but unlike ...
G F Daniel, B Goodell
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
Färbeverfahren zur Unterscheidung von Holzzonen mit unterschiedlichem Absorptionsvermögen, insbesondere bei Fichtenholz (Picea abies Karst.). [Staining method for distinguishing zones of wood with different absorption behaviour, particularly in spruce (Picea abies Karst.)]
1980 - IRG/WP 3163
A simple regressive staining method for crosscut wood surfaces is described. Phloroglucinol-hydrochloric acid serves as stain; flowing water and a solution of sodium carbonate are used for development and fixation of a picture showing the differences of absorption. Hydrophobic zones and, contrary to this, zones with a high water content can also be shown. Comparing green spruce wood before and dur...
S Cymorek
A comparison between high and conventional incision densities for improving preservative treatment of Douglas-fir heartwood lumber
1993 - IRG/WP 93-40009
Incising is required for the preservative treatment of most wood species from the western United States; however, there is considerable debate about the density of incisions required to achieve adequate treatment. Previous studies have shown that the incision effect on treatment is relatively narrow, suggesting that incision densities should be significantly increased over current practices and st...
S T Lebow, J J Morrell
Accelerated diffusion treatment of sawn Sitka spruce grown in the UK
1986 - IRG/WP 3395
The treatment of 'green' sapwood and heartwood of Sitka spruce by diffusion methods was investigated. Steam/dip treatment processes gave increased solution uptakes and depths of penetration of copper in comparison with a simple dip treatment. Further investigation is required to reduce diffusion gradients with copper based formulations and to improve the penetration of '...
R J Murphy, D J Dickinson
Improved preservative penetration of spruce after pre-treatment with selected fungi. II. Creosote treatment, analysis and strength testing
1998 - IRG/WP 98-40106
This paper describes the creosote treatment and analysis of logs pre-treated with selected fungal agents as a method of increasing the porosity of the wood prior to preservative treatment. The paper also reports the subsequent strength testing of the timber to evaluate the effects of the fungal pre-treatment on the structural integrity of the wood.
European spruce logs were pre-treated with eithe...
E J Tucker, A Bruce, H J Staines, B Rosner, K Messner
Improved preservative penetration of spruce after pre-treatment with selected fungi. I. Fungal pre-treatment of pole sections
1998 - IRG/WP 98-40117
European spruce logs were pre-treated with either Phanaerochete chrysosporium, Dichomitus squalens, Trichoderma viride and Trichoderma aureoviride for incubation periods of between 1-4 weeks prior to pressure treatment with creosote in a commercial treatment plant and analysed for strength and creosote uptake (see part II Tucker et al.). A method to pre-treat logs was optimised. The pole sections ...
B Rosner, K Messner, E J B Tucker, A Bruce
Influence of surface coating on the leachability of boric acid and bifluorides from spruce wood
1995 - IRG/WP 95-50050
In the Netherlands, window joinery made from non-durable timber species (spruce) are widely protected with preservative rods. These rods contain non-fixing wood preservatives (e.g. bifluorides or boric acid). This reseach was performed to show the possible influence of a coating system to hinder the leaching of the active ingredients. The results of the leaching tests show, that bifluorides and ev...
W J Homan, H Militz
Effects of Prior Establishment of Trichoderma harzianum on Ophiostoma picea Growth in Freshly Sawn Douglas-fir Sapwood
2003 - IRG/WP 03-10476
Trichoderma harzianum has been shown to be an effective biocontrol agent against a number of wood inhabiting fungi under laboratory conditions, but this fungus has performed poorly in field trials. Understanding the interactions between biocontrol agents and their intended targets in wood may provide important clues for developing improved approaches to biocontrol, potentially reducing our relianc...
Ying Xiao, J J Morrell, L M Ciuffetti
Potential for using dip/supercritical fluid treatments for wood impregnation
2004 - IRG/WP 04-40276
While supercritical fluid impregnation offers tremendous potential for impregnating wood species that resist conventional liquid preservative treatments, the resulting treatments are often not uniform among samples in a charge or between charges. One factor that influences treatment is the dynamic change in pressure that occurs during introduction of the biocide laden supercritical fluid into the ...
Sung-Mo Kang, J J Morrell
Variation in natural durability of British grown Douglas fir ((Pseudotsuga menziesii (Mirb.) Franco). Part II. Effect of extractive contents and taxifolin
2002 - IRG/WP 02-10446
The previous paper (Part I: Effect of density and growth rate) described the variation in natural durability of 4 Douglas fir (DF) seed origins (Darrington, J. Landing, Naselle and Hawkinsville) in a pure culture decay test and fungal cellar test. The pure culture tests were performed against two brown rot fungi (Coniophora puteana and Postia placenta). In the fungal cellar test soft rot was the p...
S Akhter, M D C Hale
Sterilization to limit pretreatment decay: Internal temperature during kiln drying of Douglas-fir poles
2001 - IRG/WP 01-40206
Sterilization to limit pretreatment decay: Internal temperature during kiln drying of Douglas-fir poles. Fungal colonization of poles following peeling has been the subject of considerable concern among electric utilities. While the presence of fungi does not, in itself constitute a risk, the survival of these fungi through the conventional treating processes could allow them to continue to degrad...
J J Morrell, P G Forsyth, K L Levien
Ammoniacal wood preservatives for use in non-pressure treatment of spruce and aspen poplar. Part 2
1984 - IRG/WP 3274
A series of thermal diffusion treatments were carried out on unseasoned white spruce (Picea glauca (Moench) Voss) lumber and air dry aspen poplar (Populus tremuloides Michx.) timbers using an ammoniacal copper arsenate wood preservative. Under the specific conditions described, certain charges of lumber met the present Canadian Standards Association Wood Preservation Committee's requireme...
C D Ralph, J K Shields