Your search resulted in 142 documents. Displaying 25 entries per page.
The role of chitinase in bioprotectant activity against staining fungi
1996 - IRG/WP 96-10175
Chitin is an important structural component of the hyphae of many wood staining fungi and its disruption can lead to dramatic declines in their growth. A number of bioprotectants have been shown to produce chitinases in liquid cultures, but the role of these enzymes in bioprotection remains poorly understood. The levels of these enzymes was studied by inoculating ponderosa pine sapwood wafers with...
J Liu, J J Morrell
Internal pressure development within Oriented Strand Board during supercritical fluid impregnation
2000 - IRG/WP 00-40175
Supercritical fluids (SCF) offer an attractive alternative to conventional treatment processes for delivering material into wood, but there are many unanswered questions concerning the technology. One major concern is the potential for the development of excessive pressure gradients in the wood that might exceed the material properties and lead to crushing or other pressure-induced damage. Previou...
G Oberdorfer, P E Humphrey, R J Leichti, J J Morrell
Protection of cellulose string with biocide/water repellent mixtures
1997 - IRG/WP 97-30148
Protecting cellulosic materials in soil contact poses a formidable challenge. Many soil inhabiting bacteria and fungi that cannot degrade wood can nevertheless rapidly depolymerize cellulose once its protective lignin matrix is removed. As a result, cellulose based materials are rarely used in direct contact with soil. One exception, however, is the use of cellulose string to support climbing vine...
A B Chang, J J Morrell
Penetration and absorption of water-borne preservatives in conifers from the Western United States: A preliminary report
1988 - IRG/WP 3475
The treatment of most softwoods from the western United States with waterborne chemicals poses a major challenge. Although many of these species are commercially treated with waterbornes, there is considerable debate about their treatability. At present, there is little or no information on the treatability of western wood species with waterborne chemicals. The lack of accurate treatability inform...
S Kumar, J J Morrell
The use of fumigants for controlling decay of wood: a review of their efficacy and safety
1989 - IRG/WP 3525
Volatile agricultural chemicals (fumigants) such as chloropicrin (trichloronitromethane) and sodium n-methyldithiocarbamate have been used in the United States for controlling internal decay of large dimension wood products for over 20 years. This usage has been concentrated in the electric utility industry, but fumigants are increasingly applied to protect bridge timbers, marine piling, and even ...
J J Morrell
Gelatin encapsulated fumigants for wood fumigations: Current research status
1985 - IRG/WP 3336
The fumigants chloropicrin (trichloronitromethane) and methylisothiocyanate (MIT) were encapsulated in gelatin as an alternative to liquid fumigant treatments for control of decay fungi in wooden utility poles. Gelatin-encapsulated MIT was stored for over 2 years under dry conditions without significant fumigant leakage. Gelatin encapsulated MIT and chloropicrin were released from capsules when pl...
A R Zahora, M E Corden, J J Morrell
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
Ability of heartwood extractives to inhibit the growth of a bacterial symbiont of Teredo navalis
2000 - IRG/WP 00-10369
Shipworms are important destroyers of wood in the marine environment, and wood users have long sought methods for preventing or limiting their attack. While heavy -duty wood preservatives are highly effective against these organisms, there is increasing concern about risks to non-target organisms. This has resulted in a gradual shift away from broadly toxic materials to either alternative material...
C S Love, A R Sipe, S C Cary, J J Morrell
Production of fungal protoplasts from selected wood-degrading fungi
1991 - IRG/WP 1500
Studies of hyphal morphology and the effects of various chemicals on growth are often difficult to perform on filamentous fungi because of the difficulty of observing the protoplasm through the rigid hyphae wall and because most activity occurs in a limited region near the hyphal tip. As an alternative, hyphae can be reacted with certain cell wall degrading enzymes to remove the cell wall to produ...
C Rui, J J Morrell
Laboratory methods for assessing the resistance of wood plastic composites to fungal attack.
2006 - IRG/WP 06-20340
Wood plastic composites (WPC’s) have many attractive material features including dimensional stability and resistance to moisture, but the wood in these materials remains susceptible to fungal attack. Assessing WPC decay resistance in laboratory trials has proven difficult because the slow moisture sorption characteristics of this material do not allow for sufficient fungal attack over the trad...
J J Morrell
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
Long term marine performance of ACZA treated Hem fir in Krishnapatnam harbour, east coast of India
2006 - IRG/WP 06-30409
The performance of Hem fir (Tsuga heterophylla) and Southern pine (Pinus sp.) treated with ammoniacal copper zinc arsenate (ACZA) and copper dimethyldithio carbamate (CDDC) at two retention levels of each preservative was assessed in tropical marine waters at Krishnapatnam harbour on the east coast of India. Panels treated with ACZA of lower loadings (23.1 Kg/m3) had failed in 38 months while the ...
B Tarakanadha, K S Rao, J J Morrell
Effect of fungal attack on maximum load capacity of simulated wall assemblies
2007 - IRG/WP 07-20363
The effects of moisture intrusion and fungal attack on the maximum load capacity of nailed assemblies was investigated using one white and one brown rot fungus against 4 material combinations over a 20 week period. Wetting significantly reduced the maximum load capacity of all four material combinations, while wetting and autoclaving only affected the OSB sheathing/spruce stud. The white rot fung...
N Melencion, J J Morrell
Predicting the decay resistance of timber above-ground: 2. When can reliable field data be obtained?
2007 - IRG/WP 07-20368
Application of modern performance-based engineering and design requires building products that are thoroughly characterised in terms of their ability to perform as expected over time. The engineering community is attempting to use this information to provide predicted service-lives for various building elements. Increasingly, this service-life prediction must be based on objective measurement coup...
L P Francis, A J Swain, J J Morrell
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
Effect of ozone treatment on survival of termites and wood decay fungi
2007 - IRG/WP 07-40365
There is increased concern about the potential for transport of invasive pests on or in untreated wood. Current regulations utilize heating or fumigation as mitigation tools, but both have drawbacks that have stimulated interest in new phytosanitation methods. Ozone fumigation has been shown to control insects, fungi and bacteria on a variety of agricultural products. Systems for the controlled g...
A M Taylor, L J Mason, J J Morrell
Effect of barriers on moisture content of treated and non-treated utility poles
2007 - IRG/WP 07-40369
The potential for non-biocidal barriers to slow moisture sorption was investigated using butt treated western redcedar poles immersed in either water or moist soil over a 2 year period. Moisture sorption was initially slowed by the barriers, but openings at the bottoms of the barriers eventually allowed moisture to migrate upward. Moisture levels in wrapped poles eventually reached those found in...
C S Love, J J Morrell
Preventing the introduction of Xylosandrus crassiusculus by dipping green lumber in insecticides prior to shipment
2007 - IRG/WP 07-40370
Xylosandrus crassiusculus, an ambrosia beetle native to Asia and Africa, was introduced into the southeastern United States in 1974. Since that time, this species has substantially expanded its range, causing damage to native ecosystems and healthy nursery stock. This species was found in The Dalles, Oregon in 2004, indicating that it is not limited to sub-tropical environments. This introducti...
C F Schauwecker, R F Mizell III, J J Morrell
The effect of additives on copper losses from alkaline copper treated wood
2007 - IRG/WP 07-50246
The replacement of chromated copper arsenate (CCA) by alkaline copper compounds has heightened awareness of the potential impact of copper losses on aquatic organisms. While there remains a healthy debate concerning the actual risk of copper leaching from wood preservatives into aquatic ecosystems, it is clear that reducing these losses will be necessary to avoid continued regulatory actions aga...
J Mitsuhashi, J J Morrell, L Jin, A F Preston
Preventing Xylosandrus crassiusculus Beetle Attack in Large Green Timbers Using Pyrethroid Dip Treatments
2008 - IRG/WP 08-10642
Although awareness about the risk of invasive species has increased over the past decade, a large number of highly destructive exotic pests are still being introduced around the world. One of the more important pest introductions in the Southeastern United States has been the Asian ambrosia beetle, Xylosandrus crassiusculus. This species is particularly important
because of its ability to kill...
C Schauwecker, A F Preston, J J Morrell
A preliminary note on the role of moisture absorption rate in durability assessment
2008 - IRG/WP 08-20383
The rate of moisture uptake was studied in 15 wood species using vermiculite at varying moisture levels as the exposure medium. As might be expected, moisture uptake varied widely among the species studied. While some of the more durable wood species were also resistant to moisture uptake, this was not always true. The results are discussed in relation to performance in under varying environmenta...
J J Morrell, L P Francis
Near infrared spectroscopy for the quantification of wood preservatives
2008 - IRG/WP 08-20391
Near infrared (NIR) spectroscopy is a rapid, flexible, inexpensive and non-destructive technology that has many applications, including the evaluation of many wood properties. Initial studies have indicated the potential to apply NIRS for the quantification of wood preservatives. However, further evaluation with borate and azole preservative systems has revealed that NIRS technology is challenged ...
A M Taylor, Seung H Baek, Myong K Jeong, J D Lloyd, J J Morrell
Investigating extraction of bifenthrin from composite wood products
2011 - IRG/WP 11-20467
Bifenthrin is added to resin prior to lay-up of plywood and laminated veneer lumber to provide termite protection. Analysis of this chemical in resins can be challenging. The potential for using ground wood in place of sawn material to recover bifenthrin was investigated using laminated veneer lumber composed of Douglas-fir veneers analyzed by three laboratories. Although the results differed amo...
J J Morrell, L Bell, J Norton, C Shaw
Phytosanitary standards and the potential for acceptance of chemical treatments as a phytosanitary measure
2011 - IRG/WP 11-30558
Regulations governing international trade in forest products must balance the economic and social benefits of trade with the potential risks of transporting invasive species. The International Plant Protection Convention (IPPC) is an international agreement intended to manage this process. It develops international phytosanitary standards (ISPMs) that are recognised by the World Trade Organisation...
A Uzunovic, R Stirling, J J Morrell, P I Morris, C F Schauwecker
Termite resistance of copper-based preservative supplemented aspen strandboards
2012 - IRG/WP 12-30594
Termite resistance of aspen strandboards treated with various copper-based preservative systems was evaluated in field exposure tests. Five copper-based chemicals or zinc borate were blended into aspen furnish at three retention levels prior to pressing. Tebuconazole or 4,5-dichloro-2-N-octyl-4-isothiazolin-3-one (DCOI) were added as co-biocides to selected copper-based treatments. Sections from...
J J Morrell, C Vidrine, A Preston, L Jin