Your search resulted in 112 documents. Displaying 25 entries per page.
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
Effects of air-seasoning on fungal colonization and wood strength of Douglas fir poles
1987 - IRG/WP 1315
Air seasoning economically reduces the moisture content of Douglas fir poles before pressure treatment with preservatives. Advanced decay in poles in service has resulted when decay fungi (Basidiomycetes) colonized poles during air-seasoning and survived the treatment process. These problems have led to recommendations to severely limit this practice. To determine the role of these fungi in peeled...
J J Morrell, M E Corden, R D Graham, B L Kropp, P Przybylowicz, S M Smith, C A Sexton
Effect of substrate type and moisture requirements in relation to colony initiation in two carpenter ant species
1999 - IRG/WP 99-10320
Conditions necessary for optimal colony initiation or the rate of initial colony expansion by early brood in the carpenter ant species Camponotus modoc and C. vicinus on various substrates conditioned to different moisture contents were studied. Camponotus modoc and Camponotus vicinus queens were placed in Douglas-fir, western red cedar and Styrofoam® blocks conditioned in sealed chambers at 70% ...
M E Mankowski, J J Morrell
Effect of species composition of preservative-treated Douglas fir plywood on its decay resistance
1978 - IRG/WP 2114
Plywood is now commonly used for constructional purposes in environmental situations where decay by wood-destroying fungi can be a considerable risk. However there seems to be a lack of understanding of the relative durability of plywood, both untreated and when treated with wood preservatives. Part of the reason for this situation has been the difficulty of carrying out laboratory decay tests on ...
R S Smith, P Balcaen
Development of threshold values for boron compounds in above ground exposures: Preliminary trials
1998 - IRG/WP 98-30179
Boron is increasingly used both as an initial and remedial treatment for protecting wood against fungal and insect attack. While establishing lethal dosages for boron against insects through feeding tests is relatively simple, establishing thresholds for fungal attack poses more of a challenge. Tests using boron dispersed in agar artificially surround the fungus with both boron and excess nutrient...
J J Morrell, C M Freitag, S Unger
Effects of chemical pretreatment of Douglas-fir heartwood on efficacy of potential bioprotection agents
1990 - IRG/WP 1440
Biological protection against wood decay fungi represents an environmentally attractive alternative to the use of chemicals; however, the process of identifying suitable candidates and the conditions that ensure successful protection pose major challenges. One critical aspect of this problem is to identify organisms that can rapidly and uniformly colonize the wood. Wood contains low levels of nutr...
B Dawson-Andoh, J J Morrell
Effect of post-treatment processing on leachability of ACZA-treated douglas-fir lumber
1998 - IRG/WP 98-50109
The effect of post-treatment procedures that more rapidly precipitate copper, zinc, and arsenic in douglas-fir treated with ammoniacal copper zinc arsenate (ACZA) on subsequent leaching resistance were investigated at two retentions (6.4 and 40 kg/m3). Total leaching was greater from boards treated to the higher retention. At both levels, copper was lost at the highest rate. Post-treatment process...
J J Morrell, C S Love, S Kumar, C M Freitag
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
Internal pressure development in Douglas fir lumber during pressure treatment
1997 - IRG/WP 97-40091
Preservative treatment of Douglas fir lumber to meet current industry standards poses a major challenge and a variety of methods have been developed to overcome these problems. One aspect for treatment improvement that has received less attention is the relative effect of treatment parameters on changes in pressure within the wood. Previous studies of spruce and radiata pine suggest that internal ...
P F Schneider, J J Morrell
Distribution of boron from fused borate rods in Douglas-fir transmission poles
1996 - IRG/WP 96-30112
The diffusion of boron from fused borate rods (disodium octaborate tetrachydrate) was monitored over 42 months in CCA-treated Douglas-fir transmission poles. The boric acid equivalent was estimated by the curcumin/salicylic acid color test on increment cores removed from the poles. Moisture content of the poles was quite variable but was always above 20 percent. The percent of increment core lengt...
T L Highley, F Green III, W F Finney
Movement of chloropicrin, Vapam, and methylisothiocyanate in southern pine and Douglas fir timbers
1987 - IRG/WP 3410
Douglas fir and southern pine timbers, 15.2 x 15.2 x 426 cm³ (6-in x 6-in x 14-ft), were "inoculated" with brown-rot and white-rot fungi as vapor-sensing agents to evaluate the movement and distribution of fungitoxic concentrations of chloropicrin, Vapam, and methylisothiocyanate (MIT) over a 20-week period. Residual fumigant in timbers was determined by a bioassay with Gloeophyllum trabeum. The ...
T L Highley
Effect of humidity and temperature on fastener withdrawal resistance from CCA and ACZA treated Douglas-fir
2000 - IRG/WP 00-20209
The effects of preservative treatment on fastener withdrawal was investigated in Douglas-fir lumber conditioned to two moisture regimes. In general, conditioning samples to 19% moisture content produced more substantial changes in withdrawal resistance of galvanized fasteners than did conditioning to 12%. Treatment had little or no effect on withdrawal resistance of stainless steel fasteners. With...
Sung-Mo Kang, J J Morrell
Borate diffusion from fused borate rods in douglas-fir transmission poles
1994 - IRG/WP 94-30042
Pressure-treated utility poles have given many years of excellent service, but their lifetime is often shortened by internal decay of the untreated heartwood center, particularly in refractory species, such as Douglas-fir. This paper reports the distribution of boron from fused borate rods installed in CCA-treated Douglas-fir transmission poles. The boric acid equivalent was roughly monitored by t...
T L Highley, W Finney, F Green III
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
Performance of Preservative Treated Parallel Strand Lumber in Marine Exposures.
2006 - IRG/WP 06-30407
The performance ACZA treated Douglas-fir and CCA southern pine parallel strand lumber (PSL) was studied in marine exposures in Florida or Oregon. While materials treated to retentions below the recommended levels for marine exposure were attacked in Oregon, properly treated panels of either species performed well. Panels treated with these same chemicals and exposed in Florida experienced attack ...
J J Morrell, C S Love, P Merrick
The effect of wood moisture content and rod dosage on movement of boron through Douglas-fir heartwood
2007 - IRG/WP 07-30431
The potential for moisture sorption by boron rods following application to wood to affect subsequent boron diffusion was investigated in small Douglas-fir blocks conditioned to 30, 60 or 90% moisture content (MC). MCs tended to decline over the 180 day test period, but there was no evidence that the rods acted to draw moisture away from the wood. As expected, boron movement tended to increase with...
Y Cabrera, J J Morrell
Copper fixation in ACQ-D treated Chinese fir at various temperature and relative humidity conditions
2007 - IRG/WP 07-30436
In this study, the effect of different conditions of temperature, relative humidity, and duration of post-treatments on accelerating copper fixation in ACQ-D treated Chinese fir wood blocks was investigated. The conditions include the combination of three temperatures (21, 50, and 70?) and two relative humidity levels (20% and 80%), also include four temperatures (50, 70, 90, and 110?) without con...
Jinzhen Cao, Lili Yu
Comparative study between full cell and passive impregnation method of wood preservation for laser incised Douglas-fir lumber
2007 - IRG/WP 07-40359
Many wood species are highly resistant to conventional pressure treatment. To improve the chemical impregnation into Douglas-fir (Pseudotsuga menziesii Franco) lumber, the passive impregnation method had been developed. In this study, ability of the passive impregnation for lumber was compared with a conventional full cell method. Square Douglas-fir lumber with the incising density of 10,000 holes...
Md N Islam, K Ando, H Yamauchi, Y Kobayashi, N Hattori
A comparison of rates of decay and loss in stiffness of radiata pine and Douglas fir framing lumber
2008 - IRG/WP 08-20378
Stiffness loss with time was recorded for untreated radiata pine and Douglas fir framing size lumber and preservative treated radiata pine which dad been pre-inoculated with Oligoporus placenta, a brown rot decay fungus isolated from decaying untreated radiata pine framing. Between stiffness measurements, samples were contained in a plastic tank located outside at ambient temperature. Index of Con...
M Hedley, D Page, J van der Waals
Accelerated fixation of ACQ-D treated Chinese fir with different post-treatments
2008 - IRG/WP 08-40400
With the enhanced focus on the environmental impact of the preservative-treated wood in recent years, it is necessary to perform some post treatments to prevent contamination of soil and ground water and reduce copper losses from ACQ treated wood in service. In this study, the potential of hot air, hot water, steaming and microwave post treatments to accelerate the fixation of copper in ACQ-D trea...
Lili Yu, Jinzhen Cao, P A Cooper
Radial flow of Bornmullerian fir (Abies bornmulleriana Mattf.) as affected by wood tapering and the condition of end wall structure of uniseriate ray parenchyma cells
2008 - IRG/WP 08-40441
Amenability to radial permeability of Bornmullerian fir (Abies bornmulleriana Mattf.) was studied on the base of the effects of wood tapering and the structure of end walls of uniseriate ray parenchyma cells. The results showed that the most remarkable culprits of the greatest fluid uptake (as the percentage of void volume filled by the fluid in the radial flow direction, RVVF%) are the lesser woo...
I Usta, S Aslan