Your search resulted in 142 documents. Displaying 25 entries per page.
Methods for improving preservative penetration into wood: a review
2002 - IRG/WP 02-40227
Pressure treatment technologies have been available since the mid-1830's, but the processes used for wood treatment are still largely unable to overcome the fundamental limitations of flow through semi-permeable pit membranes. Instead, methods have arisen that attempt to improve treatability of the wood including incising, compression rolling, through boring, or radial drilling. Other a...
J J Morrell, P I Morris
Effect of wood species on colonization by an unknown wood boring organisms in marine waters
1995 - IRG/WP 95-10108
The effect of wood species on the initial settlement by surface fouling organisms in marine environments was investigated by exposing heartwood panels of Douglas-fir ((Mirb.) Franco), western redcedar (Donn.), and Oregon white oak (Dougl. ex. Hooke) in an estuary located on the coast of Oregon. The oak and western redcedar panels were sparsely colonized over the first 39 days of exposure, while th...
K S Rao, P F Schnieder, J J Morrell
Colonization of treated and untreated ponderosa pine exposed in Hilo, Hawaii
1995 - IRG/WP 95-20068
The rate of decay in above ground exposures is largely controlled by rainfall and temperature, factors which can be used to construct a climate index of decay hazard in above ground exposures. Developers of new biocide formulations have utilized this knowledge by establishing test sites in sub-tropical regions such as the Gulf Coast of the United States. More recently, field sites have been locate...
C M Freitag, J J Morrell, K J Archer
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
Performance of Oriented Strandboard, Medium Density Fiberboard, Plywood, and Particleboard Treated with Tebuconazole in Supercritical Carbon Dioxide
2005 - IRG/WP 05-30364
The performance of oriented strandboard (OSB), medium density fiberboard (MDF), particleboard and plywood treated with tebuconazole using supercritical carbon dioxide was investigated over a 48 month exposure under harsh above ground conditions in Hilo, Hawaii. Samples treated to low retentions (<0.20 kg/m3) tended to experience decay at rates that were only slightly lower than those found wit...
J J Morrell, M N Acda, A R Zahora
Effect of Pseudomonas cepacia on the activity of a mixture of wood staining fungi on ponderosa pine sapwood
1995 - IRG/WP 95-10107
There are major incentives for limiting the degree of fungal discoloration which occurs during wood processing. Most lumber producers apply prophylactic fungicides which limit microbial growth, but increasing restrictions on the use of these chemicals have encouraged the search for alternative stain prevention strategies. Among the possible strategies for stain prevention is biological control. Wh...
J J Morrell, R K Velicheti
Performance of groundline bandage remedial treatments in western US species transmission poles
1993 - IRG/WP 93-30019
Groundline bandages are an important element in remedial treatment strategies for utility poles in the United States. Several bandages containing new or reformulated components have recently been developed but have not been adequately tested. This paper reports on the degree of diffusion of copper naphthenate, boron, and sodium fluoride from groundline bandages into pressuretreated Douglas-fir, po...
P G Forsyth, J J Morrell
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
Protection of pile tops using combinations of internal treatments and water shedding caps
1993 - IRG/WP 93-30020
Preservative treatment produces an excellent barrier against fungal, insect, and marine borer attack; however, fabricators often disrupt this barrier during construction, creating avenues for entry of decay agents. This problem is particularly acute in marinas along the coastal United States. Standards recommend the application of a water-shedding cap at the time of installation to prevent pile to...
P Schnieder, M A Newbill, 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
Borates as wood preserving compounds: The status of research in the United States
1989 - IRG/WP 3542
This paper describes the extensive, on-going cooperative research effort among government and university research laboratories and industry to fully evaluate the potential for borates as wood preservatives in the United States. Research is discussed in terms of laboratory evaluations, field testing and mill trials, pilot plant pressure treatment studies, and remedial treatments. Future research pl...
H M Barnes, T L Amburgey, L H Williams, J J Morrell
After 18 years, preservative dipping and brush treating continue to provide protection to shingles of western wood species
1997 - IRG/WP 97-30156
The presence of residual preservation in dip-treated and brush-treated shingles of various species from the western United States was assessed 18 years after installation using Aspergillus bioassays. The performance of western redcedar (Thuja plicata) was compared to western hemlock (Tsuga heterophylla), sugar pine (Pinus lambertiana) and western larch (Larix occidentalis). Untreated shingles of a...
T C Scheffer, D J Miller, J J Morrell
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
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