Your search resulted in 208 documents. Displaying 25 entries per page.
Cellular and fractural failure after supercritical fluid impregnation of four wood species
2004 - IRG/WP 04-10503
Supercritical fluids (SCFs) have been investigated for delivering biocides into sawn wood. Pressure differentials during treatment may exceed the compressive or tensile strength perpendicular to grain, creating a potential for transverse deformations that exceed elastic strain limits. Wood treated by SCF processing with CO2, a potential biocide carrier, was inspected macroscopically and microscopi...
M E Anderson, R J Leichti, J J Morrell
Trials of new treatments for prevention of kiln brownstain of white pine (Pinus strobus)
1995 - IRG/WP 95-30068
White pine (Pinus strobus) often develops a surface brown oxidative stain when kiln dried. Such stain downgrades high quality lumber and is most likely to occur when fresh, unseasoned lumber is stacked during warm weather prior to kiln drying. Use of reducing agents or pH alteration has been successful, but may have some practical limitations for general use. This study attempted to prevent browns...
E L Schmidt, E Christopherson, T L Highley, M H Freeman
Decay resistance of Platanus acerifolia wood against White Rot Fungi (Coriolus versicolor)
2002 - IRG/WP 02-10431
Degradation of the lignocellulose complex in wood varies on the microorganism causing decay and chemical composition of wood. The weight loss of Platanus acerifolia wood after decay by white rot fungus (Coriolus versicolor) for period 16 weeks were evaluated according to European standard EN 113 and beech wood as a control. The samples were collected in October 2000 from Nantes, France. The aim of...
M Irmouli, O Duchelier, N Ayadi, B Charrier
Secretion of ligninolytic enzymes by hyphal autolysis of the white rot fungus Phanerochaete chrysosporium
1991 - IRG/WP 1480
The secretion of ligninases by Phanerochaete chrysosporium was investigated with polyclonal antibodies, followed by immmunogold-silver staining and light microscopy. After growing fungal mycelium on nitrocellulose, extracellular ligninases were detected around old, plasmaless hyphae, but not at arthrospores, chlamydospores, or blastoconidia. Labeling of fungal hyphae on coverslip cultures was obse...
R Lackner, E Srebotnik, K Messner
Micromorphology of Schizophyllum commune attack in pine (Pinus sylvestris) wood
1983 - IRG/WP 1184
The decay pattern caused by Schizophyllum commune in pine latewood tracheids was studied using both light and transmission electron microscopy. The attack began as isolated concentric slits within the S2 layer with extensive lamellation and separation of individual wall layers observed in subsequent stages of decay. The slits resulting from attack appeared to be formed in thin, regular concentric ...
T Nilsson, G F Daniel
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
Natural durability transfer from sawmill residues of white cypress (Callitris glaucophylla). - Part 4: Analysis of extracts and treated wood for active components
2000 - IRG/WP 00-20215
In order to facilitate the commercial implementation of a large project aimed at recovering 'waste' durability components from sawmill residues of Callitris glaucophylla, it has been essential to develop analytical methodology for the important bioactive components of the heartwood extract. This methodology will be used 1) to standardise the activity of successive production batc...
Hui Jiang, M J Kennedy, L M Stephens
Fungal colonisation of the keelson and associated structures of a nineteenth century wooden frigate: Concepts of community structure and development
1994 - IRG/WP 94-10072
The early stages of microbial colonization and succession of wooden surfaces exposed to the sea have been extensively studied as have the community structures of archaeological timbers subjected to submergence and then retrieval from the sea. The frigate UNICORN, a largely intact 19th century wooden ship based in Dundee, Scotland, provides the microbial ecologist with a unique opportunity to study...
N A White, J W Palfreyman, G M Smith
Effects of cyproconazole and copper sulphate on the length of the hyphal growth unit (HGU) of the white-rot fungus Coriolus versicolor
2003 - IRG/WP 03-10473
Wood decay basidiomycetes have been shown to produce appreciable quantities of extracellular mucilaginous materials (ECMM). The relationship between ECMM and total biomass production has been investigated in the white-rot fungus Coriolus versicolor (CTB 863 A). Differences in the amount of ECMM produced by the fungus proportionally to the total biomass, were observed under a range of physiological...
D Vesentini, D J Dickinson, R J Murphy
Utilization of coconut timber from north Sulawesi, Indonesia. Part 1: Durability
1994 - IRG/WP 94-30044
Coconut timber from non-productive plantations is a byproduct of an agricultural crop and, by the same token, constitutes a renewable resource which may serve as a complement to or, at least in part, as a substitute for traditional timbers in local markets. Its more extensive utilization is expected to contribute to the conservation of tropical rain forests. Export of coconut timber and/or wood pr...
R-D Peek
Kerfing reduces checking in ACA-treated western white spruce poles
1988 - IRG/WP 3477
Western white spruce poles, pressure treated with pentachlorophenol and ammoniacal copper arsenate (ACA) were installed in the Westham Island test site. The pentachlorophenol treated poles were unkerfed, while both unkerfed and kerfed ACA poles were placed in test. The checking and kerf width and depth were recorded at the time of installation. After ten years of weathering the checking characteri...
J N R Ruddick
Extracellular substance from the white rot basidiomycete Irpex lacteus involved in wood degradation
1992 - IRG/WP 92-1571
Cellulases, phenol oxidase, and a substance that both produced and reduced H2O2 were isolated from cultures containing wood or glucose on which the white-rot fungus Irpex lacteus was growing. The rate of wood degradation by the fungus with different amounts of glucose in the medium was measured. More of the substance that produced and reduced H2O2 was found extracellularly in cultures containing w...
H Tanaka, T Hirano, G Fuse, A Enoki
Lab and field test results for wood treated with polymeric alkylphenol polysulfide
2001 - IRG/WP 01-30268
A new wood preservative based on polymeric alkyphenol polysulfide (PXTS-A) is being evaluated in a series of laboratory and field tests and the results continue to show promise. A modified formulation (PXTS-B), which contains additives to reduce the viscosity, is being evaluated along with the original formulation. Soil block decay tests comparing PXTS-B with CCA-C indicate that PXTS-B is equally ...
J Goswami, A Abramson, R Buff, D D Nicholas, T Schultz
Durability aspects of (hydro)thermal treated wood
2000 - IRG/WP 00-40160
Samples of several wood species were treated in a two steps process, subsequently hydrothermal and dry heat-treated, by the so-called PLATO-process and analysed for their resistance against fungal attack. Both PLATO-treated and dry heat-treated specimen were prepared and analysed, in order to study the influence of moisture during hydrothermal treatment of wood. The resistance against all of the s...
B F Tjeerdsma, M Stevens, H Militz
Relative merits of laboratory and field tests for assessing wood decay resistance
1993 - IRG/WP 93-20009
Laboratory and field trials have long been employed for assessing natural durability of a variety of wood species, but there is a continuing debate concerning the relative merits of approach. While laboratory tests provide carefully controlled conditions for decay, they are often criticized for being too artificial to produce meaningful results. Conversely, field trials often vary widely between t...
T C Scheffer, J J Morrell
Sampling and analysis of NeXgen-treated timber
1998 - IRG/WP 98-20134
Green sawn timber surfaces of the softwood Caribbean pine and the hardwood white cheesewood were treated by dipping, spraying, and precise spiking with the antisapstain product NeXgen. After storing for either two hours or two weeks, the treated surfaces were sampled by one of four alternative protocols, which included two involving a square wad sampling punch (one hit or six hits), one involving ...
M J Kennedy, D E Ferlazzo, T L Woods, M H Freeman
Cytoplasmic and extracellular localization of manganese II dependent peroxidase(s) in white rot fungi during degradation of woody materials
1989 - IRG/WP 1416
The manner by which lignin is degraded in-situ in natural substrates by white rot fungi still remains a controversial issue particularly the distribution and role(s) played by lignin degrading enzymes (i.e. manganese II peroxidase and lignin peroxidase). In the present study, use was made of anti-manganese II peroxidase and immunolabelling techniques in conjunction with transmission electron micro...
G F Daniel, B Pettersson, T Nilsson, J Volc
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
Synergistic combination of an antioxidant and wood preservative: a preliminary study
1998 - IRG/WP 98-30172
We previously proposed that extractives in highly durable angiosperm heartwood may protect wood against white-rot fungal colonization and subsequent degradation by a dual mechanism: extractives have some fungicidal activity and are also free radical scavengers (antioxidants) and thus interfere with the fungal free radical degradative mechanisms. We tested this hypothesis using the commercial bioci...
T Schultz, D D Nicholas, J Minn, K D McMurtrey, T H Fisher
Microscopic analysis of southern pine utility pole core segments
1992 - IRG/WP 92-1542
Fifteen macroscopic core descriptive categories were evaluated by microscopic analysis for accuracy in detecting decay and judging decay severity. Five categories were good indicators of decay as decay was detected in 28 of 48 samples. Five categories were possible indicators of early decay as decay was detected in 6 of 40 core segments and an additional 18 contained hyphae. The remaining five cat...
S E Anagnost, C J K Wang, M Wright
Mechanistic aspects of the reactions of copper complexes with lignin in the presence of hydrogen peroxide and lipid hydroperoxide model compounds as proposed for white rot fungi
2001 - IRG/WP 01-10399
The structural principles and the oxidative reactions of the catalytic system consisting of copper, hydroperoxides, and copper coordination compounds that contain aromatic nitrogen atoms are similar to those of catalytic centers of oxidative enzymes involved in delignification reactions of white rot fungi. The system is capable of selectively degrading lignin and its low molecular weight would all...
K Fackler, P Lamaipis, E Srebotnik, M Humar, C Tavzes, F Pohleven, M Sentjurc, T Watanabe, K Messner
Fruitbody formation and basidiosporogenesis by the white rot fungus Pycnoporus cinnabarinus
1988 - IRG/WP 1348
Conditions for fruitbody formation by the white rot fungus Pycnoporus cinnabarinus in vitro were outlined. A marked difference in substrate requirements in comparison to previously tested brown rot fungi was revealed. Agar media containing Walseth cellulose and NH4 tartrate at 1 g/l permit profound production of basidiospores particularly at 15°C but only under light treatment. Higher NH4 tartrat...
J Bjurman
The nature of osmiophilic particles and their distribution during different stages of brown and white rot decay
1983 - IRG/WP 1213
The distribution of osmiophilic particles during the course of brown and white rot decay was investigated by applying transmission electron microscopic (TEM) methods. It was found that it correlates with the brown and white rot pattern.The osmiophilic particles are produced by the fungus and are supposed to be wood rotting enzymes....
K Messner, H Stachelberger
Evaluation of the natural durability and ultrasonic method for decay detection of some european hardwood and softwood species
2004 - IRG/WP 04-10537
This paper presents the first part of an investigation on the natural durability of mixed plywood made of durable and non durable plies from the following selected timbers : Cedrus atlantica, Cupressus sempervirens, Castanea sativa, Populus sp. I 214 and Fagus sylvatica.
In order to carry out this study, the natural durability of the massive wood used to manufacture the plywood panels was asses...
F Faraji, M-F Thévenon, B Thibaut