Your search resulted in 228 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
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
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
Impact of sapwood portions on the durability of adjacent heartwood of Pinus sylvestris, Pseudotsuga menziesii and Quercus robur. Part 1: Laboratory studies
2018 - IRG/WP 18-10922
Sapwood is generally considered as non-durable and assigned to durability class DC 5 according to European standards independent from the wood species. It is commonly agreed that sapwood decays faster than adjacent heartwood, but it is controversially discussed whether sapwood serves as feeder material and thus accelerates onset and progress of decay in more durable heartwood or decays independent...
C Brischke, P Homann, A Gellerich
Interaction of Boultonizing and through-boring of Douglas fir sapwood
2018 - IRG/WP 18-40833
The interaction of combining through-boring and Boultonizing treatment effects on strength properties was investigated. Small, clear Douglas fir beams were through-bored and/or Boultonized in full factorial design and evaluated for toughness, MOE and MOR. The simulated through-boring treatment lowered the mechanical properties but the Boultonizing process did not. There was also no evidence for a ...
F Gasteiger, J Lloyd, A Taylor
Application of radio frequency heating to accelerate fixation of CCA in treated round-wood
1999 - IRG/WP 99-40133
The potential of radio frequency heating to accelerate the fixation of chromated copper arsenate (CCA) in treated round-wood was assessed. Pre-dried Douglas-fir and western red cedar round-wood sections were pressure treated with CCA in a pilot plant retort, after which they were placed individually in a pilot radio frequency (RF) chamber. Based upon the color reaction of chromotropic acid with he...
Fang Fang, J N R Ruddick
Treatability of plywood containing intermountain Douglas fir veneers
1982 - IRG/WP 3203
Eighteen sheets of plywood were obtained which contained intermountain Douglas-fir veneers from two regions of British Columbia. Following pressure treatment with chromated copper arsenate (CCA type C) and ammoniacal copper arsenate (ACA) the preservative penetration and retention in individual veneers was assessed. It was concluded from the study that the intermountain Douglas-fir veneer could no...
J N R Ruddick, A Walsh
Effect of a penta emulsion on the service life of Douglas fir, heartwood posts
1978 - IRG/WP 3112
C S Walters
Long-term effectiveness of fumigants in controlling decay in Douglas fir waterfront timbers
1986 - IRG/WP 3364
The persistence, movement, and effectiveness of chloropicrin and Vapam (sodium N-methyl dithiocarbamate) in large, horizontal Douglas fir timbers were evaluated 7 years after fumigation. Chloropicrin prevented reestablishment of decay fungi; reinvasion occurred in some Vapam-treated timbers. Residual fungistatic effect was detected up to 1.2 m from the fumigation site in chloropicrintreated timber...
T L Highley
Movement of boron from fused boron rods implanted in Southern pine, Douglas fir, red oak, and white oak timbers
1995 - IRG/WP 95-30061
This paper reports the distribution of boron from fused boron rods installed into six-inch (15.2 cm) square timbers of Douglas-fir, Southern Pine, red oak and white oak exposed aboveground. The composition and size of rods was: sodium borate and sodium borate-copper oxide (8.5 x 100 mm²); sodium borate-copper, sodium borate and boric oxide-copper oxide (12 x 76 mm²). The boric acid equivalent wa...
T L Highley, L Ferge
Sequential exposure of borate treated Douglas-fir to multiple Formosan subterranean termite colonies in a 40-week field test
1993 - IRG/WP 93-10006
Douglas-fir boards (ca. 74.5 g) pressure-treated with disodium octaborate tetrahydrate (DOT) retentions of 0 (controls), 0.88, 1.23, 1.60, or 2.10% (weight/weight) DOT were sequentially exposed to four active field colonies of Formosan subterranean termites, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), in an above-ground field test. Samples were placed in contact with each colony fo...
J K Grace, R T Yamamoto
Effect of fatty acid removal on treatability of Douglas-fir
1993 - IRG/WP 93-40008
Treatment of Douglas-fir with chromated-copper-arsenate (CCA) poses a major challenge. Several hypotheses based on the anatomical aspects as well as chemical reactivity of the preservative formulations with cell wall constituents and deposits have been proposed. Techniques to prevent pit aspiration or slow fixation reactions have, however, not significantly improved treatment. The presence of high...
S Kumar, J J Morrell
Studies on the biological improvement of permeability in New Zealand grown Douglas fir
1983 - IRG/WP 3231
This report outlines progress towards optimizing conditions for water storage of New Zealand grown Douglas fir with the aim of improving permeability to water-borne preservatives, in particular CCA. Small scale laboratory tests are in progress but the need to scale up to potential commercial applications is being considered. Mixed populations of bacteria isolated from 10 week water sprinkled Dougl...
K J Archer
Treatment of Douglas fir heartwood with disodium octaborate tetrahydrate (Tim-BorÒ ) to prevent attack by the Formosan subterranean termite
1991 - IRG/WP 1487
Toxicity of disodium octaborate tetrahydrate (Tim-BorÒ) to Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae), and termite feeding on treated Douglas-fir heartwood were evaluated in laboratory and field tests. Feeding on filter papers impregnated with Tim-BorÒ solutions reduced but did not eliminate termite gut protozoan populations. In a forced-feeding laboratory assay, Douglas-fir hear...
M Tamashiro, R T Yamamoto, J K Grace
Development of decay in untreated, second-growth Douglas-Fir using two exposure techniques in North Queensland
1997 - IRG/WP 97-20110
The results of two exposure techniques for evaluating the development of wood decay in untreated, mill-run lumber from second-growth Douglas-fir containing both sapwood and heartwood are presented. Nominal 50 mm by 100 mm by 2.5 m (2 in. by 4 in. by 8 ft) lumber, No 2 and better, was obtained from a production run in a mill that was processing second growth, Coastal Douglas-fir in western Oregon, ...
J Norton, S Kleinschmidt, R C De Groot, D Crawford
Migration of Metals from Douglas-fir Lumber Treated with ACZA or Pentachlorophenol Using Best Management Practices: Preliminary Tests
2005 - IRG/WP 05-50224-4
The potential for migration of preservative components from ammoniacal copper zinc arsenate (ACZA) and pentachlorophenol treated Douglas-fir lumber in non-soil contact exposure was assessed in a simulated rainfall device. Metal levels from ACZA treated wood were elevated for the first 30 minutes of rainfall and then declined sharply. Repeated cycles of rainfall led to declines in initial metal l...
J J Morrell, Hua Chen, J Simonsen
The effect of selective additives and conditions on the decomposition of Basamid in Douglas fir heartwood
1992 - IRG/WP 92-3698
Basamid is a solid, powdered chemical used as an agricultural soil fumigant. Decomposition of Basamid isothiocyanate, hydrogen sulfide, methyl amine, and formaldehyde. Basamid has some potential as a wood fumigant, but it decomposes too slowly to be effective. Various additives and conditions were tested for their ability to enhance Basamid decomposition in Douglas-fir heartwood. Higher MC&apo...
P G Forsyth, J J Morrell
Effect of incising depth and density on treatment of Douglas fir, hem fir and spruce-pine-fir lumber with CCA, ACZA or ACQ
1997 - IRG/WP 97-40093
Incising markedly improves both the depth and uniformity of preservative treatment of refractory wood species, but there are few studies directly comparing the effects of incising depth and density on penetration and retention of commonly used waterborne preservatives in wood species from the western United States. The effects of two incision densities (7300 and 8900 incisions/square meter) at two...
M Anderson, J J Morrell, J E Winandy
Movement and persistence of Dazomet and pellected methylisothiocyanate in wrapped Douglas fir and southern pine timbers
1991 - IRG/WP 1496
The movement and persistence of Dazomet (tetrahydro-3,5-dimethyl-2 H-1,3,5 thiadiazine-6-thione) and pelleted methylisothiocyanate (MIT) was evaluated in wrapped Douglas-fir and Southern Pine timbers. MIT pellets did not impart a fungistatic effect to any of the timbers. Failure of MIT was probably due to loss of MIT from pellets prior to application. Fungistatic effect of Dazomet was consistently...
T L Highley
Comparative moisture uptake of Douglas fir and radiata pine structural lumber when exposed to rain wetting as an indicator of relative decay resistance
2004 - IRG/WP 04-20285
Trials were undertaken to determine the relative resistance of radiata pine and Douglas-fir to wetting when exposed to the weather.
Douglas-fir samples were obtained from one Central North Island and three South Island sources and had a heartwood/sapwood mix typical for each resource. Radiata pine sapwood and heartwood samples were obtained from a Central North Island source. Material was exposed...
M E Hedley, G Durbin, L Wichmann-Hansen, L Knowles
Relationship between bond strength and surface characteristics of CCA-treated Douglas-fir
1993 - IRG/WP 93-30008
Chromated-copper-arsenate (CCA) treated Douglas-fir was laminated using a commercial phenol-resorcinol resin. CCA treatment enhanced the water repelleney of wood espeeially in the presence of extractives. However, the shear strength of CCA treated wood was 12% lower in dry condition and 38% lower in wet condition after six cycles of vacuum-pressure test than that of untreated wood. Slight removal ...
K Yamamoto, J N R Ruddick
Diffusion of a copper naphthenate/boron paste through Douglas fir heartwood
1991 - IRG/WP 3671
Groundline wraps are an important portion of the remedial treatment strategies for protecting utility poles in North America from surface decay. The compositions of these wraps have recently shifted away from pentachlorophenol and creosote to formulations containing copper naphthenate and boron. These formulations have not yet been extensively tested, although the chemicals have been used for many...
P G Forsyth, J J Morrell
Serviceability of copper naphthenate-treated poles
2000 - IRG/WP 00-30214
Copper naphthenate-treated poles in service were inspected for deterioration, penetration, retention, and serviceability. The study to date has included poles in all hazard zones in the United States. Poles installed by 12 different utilities and eight different treating companies are included in the survey. Both southern pine and Douglas-fir poles and distribution and transmission poles are inclu...
H M Barnes, M H Freeman, J A Brient, C N Kerr Jr
The influence of wood moisture content on the fungitoxicity of methylisothiocyanate in Douglas fir heartwood
1987 - IRG/WP 3430
The fumigant methylisothiocyanate (MIT) effectively controls decay fungi in large wood structures, but the influence of environmental factors on its performance are not well understood. Experiments found wood moisture content to greatly influence the fungitoxicity and sorption of MIT in Douglas fir heartwood. At constant, low MIT vapor concentrations (less than 1 µg/cc air), wood at 10% MC bound ...
A R Zahora, J J Morrell
Performance of boron and fluoride based rods as remedial treatments in Douglas-fir poles
1995 - IRG/WP 95-30070
Boron and fluoride are widely used for remedial internal treatments, but their use in North America has been limited. Recently, however, interest in these chemicals has increased as the result of concerns about the risks of fumigant usage. The performance of boron or a boron/fluoride combination was assessed in Douglas-fir poles over 1 to 3 year periods. Both chemical formulations diffused well th...
J J Morrell, P F Schneider