Your search resulted in 303 documents. Displaying 25 entries per page.
Biodegradation of wood in wet environments: A review
1997 - IRG/WP 97-10217
Wood in wet environments is attacked and degraded by soft rot fungi and erosion and tunnelling bacteria, which are more tolerant to high moisture and reduced oxygen conditions than basidiomycetes, such as white and brown rot fungi. Since basidiomycetes are normally more aggressive and can degrade wood faster than soft rot fungi and bacteria wood in wet environments can survive longer. In fact, arc...
A P Singh, Yoon Soo Kim
Evidence for the participation of the osmiophilic particles in the enzymatic demethylation of lignin
1984 - IRG/WP 1239
Transmission electron microscopic observations of the white-rot fungi Trametes hirsuta and Phanerochaete chrysosporium grown on a series of wood pulp with a graded lignin content and mycelium from the clarified centre of an agar-medium containing lignin (E1-effluent from the bleaching process) showed that osmiophilic particles are only induced by native lignin. Taking into account that the osmioph...
K Messner, H Stachelberger
Production of exraxellular hydrogen peroxide and oxalic acid by brown-rot fungus Poria placenta
1995 - IRG/WP 95-10112
Hydrogen peroxide and oxalic acid have been suggested to be essential in the degradation of wood carbohydrates by brown-rot fungi. Hydrogen peroxide has been suggested to be one of the diffusible low molecular weight agents produced by brown-rot fungi for the degradation of wood carbohydrates by generating highly active radicals. The production of hydrogen peroxide and oxalic acid by Poria placent...
A-C Ritschkoff, M Rättö, J Buchert, L Viikari
Some recent studies on the marine wood-borers of the west coast of India
1982 - IRG/WP 486
Occurrence and distribution of marine wood-borers along the west coast of India from Mangalore to Kandla are presented together with the distribution pattern of all the molluscan and crustacean wood-borers so far reported from India coasts. The survey, conducted for the first time along this coast, revealed the presence of 14 species of Teredinidae, 2 species of Pholadidae, 3 species and one varie...
L N Santhakumaran
Degradation features of waterlogged archaeological compression wood
1998 - IRG/WP 98-10258
The degradation characteristics of waterlogged archaeological compression wood excavated in South Korea were examined by transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). Degradation of Pinus compression wood occurred mainly in the inner part of S2 layer. In contrast, the outer part of S2 layer remained relatively intact. CLSM and TEM showed the erosion type of ...
Yoon Soo Kim, A P Singh
Pyrolysis GC-MS as a tool for lignin analysis
1987 - IRG/WP 2201
Pyrolysis-GC-MS is a rapid process for analysis of rather complex organic compounds. The method has great application to petroleum shale oil and wood lignin. Small powdered samples (several mg) are placed in silica capillary tubes and rapidly heated in an inert atmosphere such as He or N2. Breakdown products of the pyrolysis are then trapped and held for an allocated time in an injector attached t...
L Doimo
The degradation of wood by metal fastenings and fittings
1972 - IRG/WP 302
As well as the hazards of biological decay, timber used in boat building is subject to the effects of chemical decay associated with the corrosion of metallic fastenings. The title has been deliberately chosen to emphasize that in wooden construction the troubles are not just those of corrosion of the fastenings, but also the destructive secondary effects on the wood caused by the products of the ...
L C Pinion
Bacteria are important degraders of cooling tower timbers: New Zealand experience
1995 - IRG/WP 95-10128
Microscopic examinations of CCA-treated Pinus radiata timbers in industrial cooling towers in New Zealand showed bacteria and soft rot fungi to be primarily responsible for the decay of these timbers. Of these micro-organisms, erosion bacteria appeared to be most widespread, attacking wood cell walls independently as well as together with tunnelling bacteria and soft rot fungi. Tunnelling bacteria...
A P Singh, R N Wakeling
New approaches to practical evaluation method of bio-degradation of wooden construction - Non-destructive detection of defects using radar technique
2000 - IRG/WP 00-20214
There have been a number of researches and developments on the techniques and apparatus for the nondestructive evaluation of the biological deterioration in wood and wooden constructions, such as decay or insect attack in house, public buildings or in historically important architectures. As for the detection of the decay in wood, techniques using sound in audible or in ultrasonic frequency ranges...
Y Fujii, Y Komatsu, Y Yanase, S Okumura, Y Imamura, M Tarumi, H Takiuchi, A Inai
Aspects of leaching
1976 - IRG/WP 267
With respect to Document No: IRG/WP/246, and the recommendation that an economic leaching test can be based on a non-changing volume of water (500 ml/block), I would like to relate our experiences with this suggestion. Following 14 days of continuous immersion in de-ionized water it was found that blocks treated with moderate and above concentrations of a preservative gave no problems, but those b...
R S Smith
Distribution of the three symbiotic protozoa in Formosan subterranean termite, Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae)
1993 - IRG/WP 93-10010
Six colonies (three each from laboratory and field) of Formosan subterranean termite, Coptotermes formosanus Shiraki, were served for investigating the abundance and distribution of three symbiotic protozoa in the hindgut of workers. The total protozoan number amounted to 6,000-10,000 per a worker, and the order of the abundance of the three protozoa and the proportional distribution of each speci...
T Yoshimura, K Tsunoda, M Takahashi
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
Über Hausbock Hylotrupes bajulus (L.), (Col., Cerambycidae), in Laubholz: Versuche mit Laubholzarten, Prüfung der Wirkung von Ligninstoffen und von Ginkgo biloba, Beobachtungen an Hesperophanes. [On House-longhorn Beetle Hylotrupes bajulus (L.), (Col., Cerambycidae) in hardwood: Investigations with several hardwood-species, tests on activity of lignin components and Ginkgo biloba, observations on Hesperophanes]
1982 - IRG/WP 1144
Hylotrupes bajulus-larvae feed and develop in softwoods, hardwood acts as a feeding poison. The reason for this is still little known. According to literature some observations contradict this established opinion and the question was raised, whether the colour-strain scutifer (= lividus) is able to live in hardwood. Testing ten European and tropical hardwood-species (following the DIN-EN test proc...
S Cymorek
Permanence of permethrin and bifenthrin in framing timbers subjected to hazard class 3 exposure
2005 - IRG/WP 05-30383
End-sealed Pinus radiata specimens measuring 235 x 90 x 35 mm were treated using a modified Lowry schedule with permethrin or bifenthrin in white spirit to Hazard Class 2 (H2) retentions. After conditioning, the specimens were exposed at 45o on north facing racks near Melbourne (Australia). Samples of the specimens were taken before installation, and after three and six months exposure. Analyses o...
A C Hunt, D G Humphrey, R Wearne, L J Cookson
Aspects of the fungal degradation of quaternary ammonium compounds in liquid culture
1997 - IRG/WP 97-30160
Didecyldimethylammonium chloride (DDAC) is a quaternary ammonium compound (QAC) that has found use as an anti-sapstain preservative for the transportation of softwood lumber from Canada to overseas markets. However, its use is limited by the knowledge that certain mould fungi seem capable of degrading it. The aim of this research was to gain knowledge about the fungal degradation of DDAC. The effe...
J W Dubois, J N R Ruddick
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
Respiration measurement of dry-rot
1995 - IRG/WP 95-10095
Methods for measuring the production of carbondioxide from wood infected with the dry-rot fungus were evaluated. By enclosing whole wood blocks and measuring the concentration of gas in the headspace by gas chromatography, an exponential increase in the concentration of CO2 was observed for at least 2 months. This technique could therefore present a method for evaluating various treatments of dry-...
L Toft
Durability of heat-treated wood
1999 - IRG/WP 99-40145
Heat-treated wood from the French process were laboratory tested against decay using agar block test and a modified soil block test. Water absorption, bending strength, lignin content and acid number were also determined to evaluate the effect of heat treatment. Heat treated samples exhibit a higher lignin content and a lower acid number compared to untreated control indicating the degradation of ...
D P Kamdem, A Pizzi, R Guyonnet, A Jermannaud
Alternative technologies for wood wastes recycling - Part A: Supercritical extraction of PAH compounds from wood wastes
1998 - IRG/WP 98-50101-18 a
Alternative technologies have been investigated to detoxify treated wood. Two classes of organic compounds are studied. Creosote-treated wood are classified in France as dangerous wood wastes. A conventional incineration could be provided for these wood wastes but the cost of this elimination could be very high (> 2000 FFR/ton). For these reasons, we have tested two kinds of new processes as al...
L Schrive, C Perre, G Labat
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
Premature failure of CCA treated vineyard posts from brown rot
1993 - IRG/WP 93-10016
A survey of CCA (AWPA Type C) treated posts used as grape vine trellis supports, to determine the extent and type of decay was carried out at a terraced vineyard in the Hawkes Bay region of the North Island of New Zealand. Of 357 posts examined out of a total of 970 in the vineyard, 47% had moderate to severe decay or had failed, 20% had established decay, 10% had a trace of decay and 23% had no s...
R N Wakeling, A P Singh
Study of the degradation caused by micro-organisms in Pinus sp. waterlogged wood
1989 - IRG/WP 1411
So far, the different Centers are trying the restoration and the conservation of wood structures, coming from subaquatic archeological deposits, with interest from the historic - artistic point of view. The main objective of this paper has been the determination of the decay level of Pinus sp. wood coming from a roman ship (approximately 2000 years old), where we have analyzed their physical prope...
M T De Troya, M C Escorial, J Garcia, A Cabanas
Effect of some resin treatments on fungal degradation reactions
1999 - IRG/WP 99-10318
The effect of impregnation of wood with vegetable oil, tall oil and two water soluble on fungal degradation reactions was assessed by hydrolysis and enzyme activity measurements. The experiments were carried out by using isolated enzyme preparations and a living brown-rot fungus Poria placenta. The results indicate that the inhibitory effect of treatments was clearly directec towards the enzymatic...
A-C Ritschkoff, M Rättö, A J Nurmi, H Kokko, A O Rapp, H Militz
Resistance of acetylated wood to biological degradation. Evaluation of field test
1997 - IRG/WP 97-30139
Acetylated wood samples were tested in ground contact (stake test) at two test fields, one in Simlångsdalen, Sweden, and one in Viikki, Finland, according to European standard EN 252. The test samples were inspected annually and their condition was compared with that of untreated controls and of samples treated with two reference CCA preservatives. The use of untreated controls and preservative t...
P Larsson Brelid, R Simonson, Ö Bergman
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