Your search resulted in 153 documents. Displaying 25 entries per page.
Improvement of some technological and biological properties of poplar wood by impregnation with aqueous macromolecular compounds
1992 - IRG/WP 92-3721
Poplars (Populus spp) belong to the most important tree species in afforestation programs of the Netherlands. Due to their rapid growth, the wood quality is usually low. Therefore, studies were performed to elucidate whether some technological properties and the resistance against fungal attack could be improved by impregnation with water-soluble resins. The results showed that swelling and shrink...
R D Peek, H Militz, J J Kettenis
A light and electron microscopic study of decayed CCA-treated radiata pine (Pinus radiata) wood from a cooling tower
1994 - IRG/WP 94-10056
An inspection of an industrial cooling tower in New Zealand showed surface decay of 12 year old Pinus radiata wood panels treated with CCA preservative to a retention of around 15 kg/m³ of salt. Wood decay micromorphology typical of that caused by soft rot fungi, white rot fungi, 'stripy' and 'v-shaped' erosion bacteria and cavitation bacteria were all commonly...
A P Singh, R N Wakeling, D R Page
Microbial decay of an archaeological wood
1994 - IRG/WP 94-10053
A light and transmission electron microscopic investigation of an archaeological wood was undertaken to determine the cause of its deterioration. The wood came from a bulwark constructed in early 1100 in the lake Tingstäde Träsk on the island Gotland in Sweden. The samples of the wood, which was identified as Pinus sylvestris, were taken from a depth of 0.85 m below the bottom level. The wood wa...
A P Singh, T Nilsson, G F Daniel
Accelerated decay tests on DNBP-treated Pinus patula and Eucalyptus grandis
1987 - IRG/WP 3441
Blocks (10 x 10 x 5 mm³) of Pinus patula and Eucalyptus grandis were impregnated to 0, 1.5, 3.0 and 4.5 kg/m³ 2-sec-butyl, 4, 6 dinitrophenol (DNBP). They were monitored microscopically and for weight losses over 16 weeks against monocultures of Coriolus versicolor and Coniophora puteana. Treated ministakes (10 x 10 x 100 mm³) and blocks in soil contact were similarly monitored to determine wei...
L D Abraham, A A W Baecker
SEM investigation of the production of extracellular mucilaginous material (ECM) by some wood inhabiting and wood decay fungi when grown on inert surfaces
1997 - IRG/WP 97-10194
A range of wood inhabiting and wood decay fungi have been studied for their production of extracellular mucilage when grown on inert surfaces, for comparison with their growth on wood. The species tested were: Coniophora puteana, Coriolus versicolor, Chaetomium globosum, Trichoderma harzianum, Ceratocystis coerulescens, Ophiostoma piceae, Mucor sp. and Penicillium sp. They were grown on plastic me...
A R Abu, R J Murphy, D J Dickinson
Proposed model for the penetration and decay of wood by the hyphal sheath of the brown-rot fungus Postia placenta
1989 - IRG/WP 1391
Scanning electron microscopy (SEM) of Pinus sp. decayed by the brown-rot fungus Postia placenta confirmed the existence of extracellular membranous structures previously described by transmission electron microscopy (TEM). These structures appear to be an integral part of the hyphal sheath and assume a variety of forms including lamellar sheets, fibrils, and vesicles. These structures were observe...
F Green III, M J Larsen, L L Murmanis, T L Highley
Comparative studies on the species effects of wood preservatives
1989 - IRG/WP 3521
For the examination of the resistance against fungal attack, wood blocks of 3 softwood species were treated with CCA (type 3), CFK, AAC and IF-1000 independently. The wood blocks were exposed to the fungal decay with Tyromyces palustris. The degradation of the wood blocks treated with these preservatives was quite widely different among wood species examined in this study. Hem-fir treated with CCA...
K Yamamoto, S Matsuoka
Distribution of copper/chrome/boron preservative in light red meranti (Shorea leprosula) before and after exposure test for 72 months
1995 - IRG/WP 95-20073
Copper/chrome/boron (CCB) preservative at 6% w/w was impregnated into light red meranti (Shorea leprosula) by full cell process. The quantitative analysis for copper, chrome and boron contents in treated wood samples was carried out by Inductive Couple Plasma (ICP). Electron Probe Microanalyser (EPMA) was used to monitor the distribution of copper, chrome and boron in the various treated wood tiss...
S Salamah, S Ani
The colonisation pattern of anaerobic fungi in wood
1989 - IRG/WP 1403
Timber foundations may be degraded in service in anaerobic conditions. The present work was conducted to investigate whether anaerobic fungi could colonise wood, using rumen fungi as test microorganisms. Strictly anaerobic fungi were isolated and purified from cow dung and goat and sheep rumen fluids respectively. Colonisation of Eucalyptus grandis and Pinus patula by these fungi and Neocallimasti...
A H Wiederhold, M Morrison, A A W Baecker
Advances in understanding the mode of action of methylene bisthiocyanate against Sphaeropsis sapinea
2002 - IRG/WP 02-30284
The importance of arresting sapstain pre-infection in radiata pine in New Zealand, to prevent downstream sapstain in both logs and sawn timbers has been clearly demonstrated. Efforts are being made to improve the efficacy of diffusible antisapstain agents through improved understanding wood/fungicide/fungus interactions. The mechanism of action of methylene bisthiocyanate (MBT) was investigated u...
T Singh, R N Wakeling, B Kreber, A Stewart
Soft Rot Decay of Cengal (Neobalanocarpus heimii) Heartwood in Ground Contact in Relation to Extractive Microdistribution
2003 - IRG/WP 03-10501
The heartwood of cengal (Neobalanocarpus heimii, fam. Dipterocarpaceae) is naturally durable. A square-sawn utility pole specimen of cengal heartwood, after 30 years in ground contact, showed 10-15 mm surface decay all around the ground line position, accompanied with isolated surface termite attack at the decayed region. Light and transmission electron microscopy (TEM) of the decayed regions prov...
A P Singh, A H H Wong, Yoon Soo Kim, Seung-Gon Wi, Kwang Ho Lee
Rapid loss of lignin at wood surfaces during natural weathering
1992 - IRG/WP 92-2390
Thin veneers of radiata pine (Pinus radiata D. Don) were exposed to natural weathering over a period of 30 days. Incident UV radiation was monitored at the test site. FTIR internal reflectance spectroscopy was used to study the chemical changes taking place at the veneer surface during weathering. Spectra obtained show that after only 3 days exposure there was substantial delignification at veneer...
P D Evans, K J Schmalzl, A J Michell
Studies on the permeability of Norway spruce (Picea abies)
1987 - IRG/WP 2295
It is well known that the bordered pits play a dominating role for liquid transport in softwoods. The mechanism behind pit aspiration during drying or heartwood formation seems to be well understood. The reason why the fixation of the membrane (torus) to the pit opening remains almost irreversible is, however, still unclear. A technique has been developed combining so-called "solvent exchange dryi...
I Johansson, K Nordman-Edberg
Immuno-electron microscopic localization of extracellular metabolites in spruce wood decayed by brown-rot fungus Postia placenta
1990 - IRG/WP 1441
Degradation by Postia placenta in spruce and birch wood was shown to occur not only in the wood cell wall but also in the middle lamellae region. Middle lamellae was often found to be degraded along the centerline so that cells could separate along this line. Extracellular membrane structures were found surrounding the hyphae and this matrix labelled positively with antisera produced to Postia pla...
Y S Kim, B Goodell, J Jellison
Preliminary PIXE micro-analysis of copper-chrome-arsenic preservative treated Malaysian hardwoods
1999 - IRG/WP 99-20169
The novel nuclear microscopy, essentially the Particle-induced X-ray Emission (PIXE) system, was applied for examining the macro-distribution and micro-analysis of copper-chrome-arsenic (CCA) preservative in Malaysian hardwoods Koompassia malaccensis, K. excelsa, Alstonia spp. and Dipterocarpus spp., and one temperate pinewood Pinus sylvestris, where the preservative retention differed between the...
A H H Wong, R B Pearce, G W Grime, F Watt
The role of contact chemoreception in location of wood by the marine borer Limnoria (Isopoda)
1996 - IRG/WP 96-10157
This paper investigates the ability of Limnoria (Isopoda: Limnoriidae) to determine chemical differences in wood substrates, while in contact with the substrates. Test substrates were chosen on the basis of previous arguments concerning the chemical state of wood prior to Limnoria attack: microbial, ergosterol, metabolite, humic, extract and control (autoclaved) veneers were used as experimental s...
S M Henderson, S M Cragg
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
Relationship between degradation of wood, cellulose or lignin-related compounds and production of hydroxyl radical or accumulation of oxalic acid in cultures of brown-rot fungi
1994 - IRG/WP 94-10062
The degradation activities of brown rot fungi against wood, cellulose, and lignin-related compounds were measured in cultures containing glucose or wood as a carbon source. Also the activities of one-electron oxidation and hydroxyl radical production and the amount of oxalic acid present in the cultures were measured. The degradation activities of the fungi against wood, crystalline cellulose and ...
S Itakura, T Hirano, H Tanaka, A Enoki
Cell wall microdistribution of chloropicrin and methylisothiocyanate in treated spruce
1989 - IRG/WP 3548
Chloropicrin and methylisothiocyanate (MIT) residues were observed using SEM/EDXA and TEM/EDXA in treated spruce wafers that had been exposed to the vapors of the two fumigant preservatives. Chlorinated residues from chloropicrin were found throughout the wood cell wall, even in acetone extracted material. The residues were most heavily concentrated in extractive materials in the rays, but unlike ...
G F Daniel, B Goodell
Wood decay of Pinus sylvestris L. and Fagus sylvatica L. by marine fungi. Part 2
1991 - IRG/WP 1471
The water-logged wood conservation requires a good knowledge of the wood decay organims which produce the degradation. Previous conducted studies (ESCORIAL, TROYA, GARCIA DE LOS RIOS, 1990) have shown that the incubation times normally used for in vitro laboratory tests are not sufficients for a significant wood degradation. This has been the reason why the aim of this work was the study of such d...
M T De Troya, A M Navarrete, M C Escorial
Improved preservative penetration of spruce after pre-treatment with selected fungi. I. Fungal pre-treatment of pole sections
1998 - IRG/WP 98-40117
European spruce logs were pre-treated with either Phanaerochete chrysosporium, Dichomitus squalens, Trichoderma viride and Trichoderma aureoviride for incubation periods of between 1-4 weeks prior to pressure treatment with creosote in a commercial treatment plant and analysed for strength and creosote uptake (see part II Tucker et al.). A method to pre-treat logs was optimised. The pole sections ...
B Rosner, K Messner, E J B Tucker, A Bruce
Extracellular hydrogen peroxide-producing and one-electron oxidation system of brown-rot fungi
1990 - IRG/WP 1445
Wood-component-degrading compounds involved in the initial degradation of the cellulose and lignin in wood were isolated from wood-containing culture of brown-rot fungi, Gloeophyllum trabeum and Tyromyces palustris and partially purified by gel filtration on Sephadex G-25 and DEAE-Sepharose ion-exchange chromatography. The compounds were glycoproteins. The molecular weights of the glycoproteins as...
A Enoki, S Yoshioka, H Tanaka, G Fuse
The effect of a chelator mediated fenton system on activation of TMP fibres and decolorization of synthesized dyes
2004 - IRG/WP 04-50223
The purpose of this work is to improve our current knowledge of the non-enzymatic mechanisms involved in the brown rot degradation of wood, but also to study the potential applications of a chelator-mediated Fenton system in activation of wood fibers and decolorization of synthesized dyes. In this work, Electron Spin Resonance (ESR) spin-trapping techniques were used to study the generation of hyd...
Yuhui Qian, B Goodell, J Jellison
Appendage-mediated attachment in spores of lignicolous marine fungi
1982 - IRG/WP 487
The role of appendages in aiding attachment and entrapment of marine fungal spores to wood substrata is described in this paper. Scanning electron microscope (S.E.M.) observations indicated five different classes of attachment or entrapment response in the sixteen species examined. These responses varied -hith the degree to which appendages attached or entrapped spores to wood surfaces. In additio...
G Rees
Diffusion and interaction of components of water-borne preservatives in the wood cell wall
1988 - IRG/WP 3474
This study investigates the rates of diffusion and ultimate distributions of copper and arsenate components of wood preservatives in wood cell walls following vacuum treatment. Adsorption studies of copper on red pine (Pinus resinosa) and trembling aspen (Populus tremuloides) wood confirm the importance of cation exchange reactions on the ultimate distribution of copper in the wood substance and i...
P A Cooper