Your search resulted in 226 documents. Displaying 25 entries per page.
Effect of bioextracts on colonisation of radiata pine sapwood by three sapstain fungi
2003 - IRG/WP 03-10485
The objective of this study was to investigate the effect of aqueous bioextracts prepared following two-week incubation of forest soil, garden compost and chicken manure respectively, on the ability of Ophiostoma flocossum, Leptographium procerum and Sphaeropsis sapinea to colonise unseasoned radiata pine sapwood.
The research showed that all bioextracts tested retarded the rate of fungal colonis...
J van der Waals, C Chittenden, B Kreber
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
Natural durability transfer from sawmill residues of white cypress (Callitris glaucophylla). - Part 1: Optimisation of the extraction conditions
2000 - IRG/WP 00-30238
As the first phase of a large project aimed at recovering 'waste' durability components from sawmill residues of Callitris glaucophylla, several solvents and extraction methods were evaluated, initially in the laboratory and then at pilot industrial scale. Extracts were compared by crude total dissolved solids content, by chemical analysis using GC-MS and LC-MS, and by laboratory...
M J Kennedy, Hui Jiang, L M Stephens
Screening of the efficacy of tall oils against wood decaying fungi
2004 - IRG/WP 04-30354
Tall oil is a by-product in pulping of resinous wood by the sulphate process. Tall oil contains a complex mixture of wood extractives. Some of these extractives act as natural protection against wood decaying fungi while other serve as nutrition for the fungi.
This report describes a screening of the efficacy of four refined tall oils with different chemical composition on wood decaying fungi. ...
G Alfredsen, P O Flæte, A Temiz, M Eikenes, H Militz
Determination of boron levels in solution and in treated wood
1994 - IRG/WP 94-20041
Four methods of measuring boron levels in solutions were investigated. The methods compared included the azomethine-H method which is commonly used in soils and plant tissues, the methods outlined in the Australian Standard AS 1605 (1974) and in Wilson (1958), and the atomic absorption spectrophotometry method. Defect-free radiata pine (Pinus radiata D. Don) sapwood and wood flakes were treated to...
F J Romero, P Vinden, P Kho
Tunnelling bacteria
1983 - IRG/WP 1186
The micromorphology of decay in wood caused by a certain group of single-cell bacteria, called tunnelling bacteria (TB), is described. TB are characterised by their tunnelling ability within the secondary cell walls of wood fibres. Pure cultures of TB have not yet been obtained although the typical decay patterns can be reproduced using mixed bacterial cultures. Some indications of lignin degradin...
T Nilsson, G F Daniel
Micromorphology of decay in Keruing heartwood by the basidiomycetes Phellinus contiguus and Dacrymyces stillatus
2002 - IRG/WP 02-10454
This study aimed to characterise the micromorphology of fungal decay in a wooden handrailing in an above ground exposure at the Thames embankment in London. Keruing heartwood (Dipterocarpus spp.) was determined as the construction timber and the two basidiomycetes Phellinus contiguus and Dacrymyces stillatus identified as main decay organisms.
Their decay patterns within Keruing heartwood were...
G Kleist, M Ray, R J Murphy
The high decay resistance in the sapwood of the naturally durable Malaysian hardwood Belian (Eusideroxylon zwageri)
2001 - IRG/WP 01-10410
It has long been assumed that the observed natural durability of the heartwood in certain timbers is perhaps associated with a relatively lower decay susceptibility also of the sapwood of these species. While the heartwood of Belian is reputedly highly decay resistant among the tropical hardwoods of Southeast Asia, laboratory decay tests reported in this paper have also confirmed the high decay re...
A A H Wong, A P Singh
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
Controlled envelope treatments of Pinus sapwood, achieved by modifications to impregnation process and carrier solvents
2003 - IRG/WP 03-40258
Specimens of slash pine or radiata pine were treated to a target retention of 0.02% m/m permethrin with conventional light organic solvent fluids or with oil-modified fluids (Tanalith® T). Best achievable envelopes from LOSP fluids were poorly controlled, penetrating not only the target outer 0-5 mm zone (mean 0.019%, RSD 28%), but also breaking through into the 5-10 mm zone (mean 0.013%, RSD 37%...
M J Kennedy, P R S Cobham
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
Assessment of untreated Papua New Guinea timbers against subterranean termites. Progress report 2
1993 - IRG/WP 93-10040
Eight species of Papua New Guinea wood including Kwila (Intsia palembanica), Taun (Pometia pinnata), Malas (Homalium foetidum), PNG Walnut (Dracontomelon dao), Calophyllum (Calophyllum sp.), Kamarere (Eucalyptus deglupta), PNG Beech (Nothofagus spp.) and White Cheesewood (Alstonia scholaris) were exposed groun contact for their natural durability against subterranean termites. Inspection after 42 ...
M Rokova, H C Konabe
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
Effect of thickened boron in preventing conidial germination of sapwood-inhabiting fungi
1994 - IRG/WP 94-30059
We evaluated the efficacy of thickened boron preservative "Diffusolä" in preventing conidia germination of sapwood-inhabiting fungi using plate bioassay, Southern Yellow Pine and sweetgum block tests, and green pine log sections. The test fungi were sapstain fungi Ceratocystis coerulescens, Ceratocystis minor, and Aureobasidum pullulans and mold fungi, Aspergillus niger, Penicillium spp, and Tric...
S C Croan
Natural durability of larch heartwood against decay
1997 - IRG/WP 97-10201
Larch heartwood has been promoted in Sweden and in other European countries as an alternative to preservative treated timber. It has even beeen stated that larch heartwood is more durable than preservative treated timber. This paper presents a compilation of facts from scientific reports on the durability of larch heartwood. Some recent data from this department are also reported. All data suggest...
T Nilsson
Decay evaluation of the effectiveness of a LOSP envelope treatment in eucalypt and meranti heartwoods for window joinery
1996 - IRG/WP 96-30099
The effectiveness and penetration in heartwood boards of an LOSP formulation containing TBTN was examined by determining decay resistance to the white-rot fungus Perenniporia tephropora. Boards, one metre long, of Eucalyptus regnans, Eucalyptus delegatensis, Eucalyptus obliqua and Eucalyptus sieberi were treated, along with boards of 'light' and 'dark' meranti. ...
L J Cookson, A Trajstman
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
Log fumigation prevents enzyme-mediated sapwood discolorations in hardwoods
1993 - IRG/WP 93-10003
Non-microbial sapwood discolorations in hardwood lumber can cause economic loss by degrade of quality. Based on the hypothesis that the enzyme-mediated sapstain may develop in part from byproducts of parenchyma cells in wood, reshly felled logs of red oak (Quercus spp.) and sugar hackberry (Celtis laevigata) were fumigated under a plastic tarp with methyl bromide. Log sections were checked after f...
E L Schmidt, T L Amburgey
Study of modulus of rupture, circumference taper, sapwood thickness and CCA treatment of Norwegian origin Pinus sylvestris poles
1994 - IRG/WP 94-20054
Nondestructive strength testing with Pilodyn (6J) of Norwegian Pinus sylvestris poles revealed effective modulus of rupture (MOR) of 54.39 N/mm² at wet conditions after CCA-C treatment and circumference measurement revealed circumference taper of 0.021 m/n. Sapwood thickness or penetration of CCA-C study revealed that 77% poles were with sapwood thickness equivalent to 39.6% of radius of poles an...
A K Lahiry, S Begum, G N M Ilias, M A B Fakir, R U Hafiz
Prevention of non-microbial sapwood discolorations in hardwood lumber: chemical and mechanical treatments
1997 - IRG/WP 97-30137
Sapwood discolorations in hardwood lumber that are non-microbial in origin result from the formation of pigmented starch-like granules in ray parenchyma cells. These discolorations can be prevented by treating unseasoned lumber with an antioxidant (sodium bisulfite). Exposing unseasoned lumber to microwaves or treating logs with fumigants also will prevent these discolorations. Subjecting unseason...
T L Amburgey, S Kitchens
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
Nondestructive assessment of biodegradation in southern pine sapwood exposed to attack by natural populations of decay fungi and subterranean termites
1994 - IRG/WP 94-20042
Field methods for evaluating decay resistance of experimentally treated materials lack a means for quantitative measurement of residual strength. Quantitative relationships between speed of impact-induced waves travelling parallel to the grain and residual compressive strength have been demonstrated in softwood attacked by brown rot-decay fungi, but the effects of termites have not been documented...
R C De Groot, R J Ross, W Nelson
Fungal decay resistance of Rubber wood treated with heartwood extract of Rosewood
2005 - IRG/WP 05-30367
Alcoholic extract of Dalbergia latifolia heartwood was studied for its toxicity towards wood decaying fungi. Rubber wood blocks were treated with this extract to three different retention levels (0.1%, 0.2% & 0.5%) and the treated wood blocks were assessed for their resistance towards two white rot and two brown rot fungi. Treated blocks showed improved resistance over the control blocks. At 0...
A K Sethy, H C Nagaveni, S Mohan, K T Chandrashekar