Your search resulted in 1148 documents. Displaying 25 entries per page.
Patterns of bacterial attack in preservative treated eucalypt power transmission poles
1984 - IRG/WP 1223
Patterns of bacterial decay have been examined using light and scanning electron microscopy. Two morphologically distinct patterns have been recognised in preservative treated eucalypt power transmission poles. Bacterial Decay I (BDI) involves the removal of the secondary wall layers initiating with erosion of the S3 layer from the cell lumen. As decay progresses the S2 layer and S1 layer are degr...
G A Willoughby, L E Leightley
Water sprinkled pine wood: A microscope study on boards showing streaking
1993 - IRG/WP 93-10033
Boards sawn from the outer sapwood of pine lumber previously water sprinkled for periods of 10-18 weeks and kiln dried, showed streaking after staining. Two types of enhanced stain uptake were noted: 1) a more concentrated and localized form after 10 weeks and 2) a more diffuse type which developed in later stages of water sprinkling. Areas showing enhanced stain uptake were examined using light a...
G F Daniel, T Elowson, T Nilsson, A P Singh, K Liukko
The effect of low molecular weight chelators on iron chelation and free radical generation as studied by ESR measurement
2000 - IRG/WP 00-10367
The focus of this work was to improve our current knowledge of the non-enzymatic mechanisms involved in brown-rot decay. Electron Spin Resonance (ESR), also known as Electron Paramagnetic Resonance (EPR), is an attractive technique for the identification and study of chemical species containing unpaired electrons (such as radicals and certain transition metal species). ESR spin-trapping techniques...
Yuhui Qian, B Goodell
Occurrence of manganese deposits in test stakes exposed in groung contact situations
1996 - IRG/WP 96-10182
Dark spots and flecks were frequently recognized on the surface and within non-preservative treated hard- and softwood test stakes placed in soil contact. Energy dispersive X-ray microanalysis in conjunction with electron microscopy showed the flecks to be composed primarily of manganese dioxide. Detailed transmission electron microscopy observations indicated intrusion of manganese into the wood ...
G F Daniel, T Nilsson, J Volc
Comparison of the effect of different soil sources on the type and rate of decay of CCA-treated pine exposed in a soil-bed
1984 - IRG/WP 2213
The types of decay observed in CCA-treated pine posts in horticultural situations in New Zealand can be reproduced using a soil-bed exposure. Radiata pine stakelets, untreated or treated to 1.4, 2.7, or 5.4 kg/m³ with Tanalith NCA, were exposed to six different soil sources. The local nursery soil used for all standard laboratory tests was found to represent the greatest decay hazard to untreated...
J A Drysdale
How to keep coated wood structures sufficiently dry to avoid damage caused by rot
1991 - IRG/WP 2376
During the last ten years, a new type of problems with wood rot has emerged in Scandinavia. Thousands of houses have been damaged by wood rot attaching to the exterior wood panel. This paper provides an overview of finished and ongoing work in order to identify the cause of these problems. In field tests, the moisture conditions were measured in panels coated with different paint systems. The infl...
S Hjort
Biological resistance of phenol-resin treated wood
1990 - IRG/WP 3602
Biological resistance of PF (phenol formaldehyde resin) - treated wood has been tested in relation to the resin properties, wood species and biological factors. When tested using water-soluble PF (mol. wt. 170), ca. 10% RI (resin impregnation) was enough to suppress the decay of Japanese cedar (Cryptomeria japonica) and western hemlock (Tsuga heterophylla) blocks exposed to Tyromyces palustris (br...
M Takahashi, Y Imamura
Ekki heartwood - is “Durable”
2002 - IRG/WP 02-10444
Severe decay damages of bridges made of ekki (Lophira alata Banks) wood which is classified as a durable species in the EN 350:2 as already reported at the 31 IRG annual meeting. This paper deals with results of long-term decay tests of ekki heartwood specimens using 3 isolates (Loweporus tephroporus 2 strains and a fungus of other sp. from damaged ekki bridges) and Trametes versicolor as a refere...
S Doi, R Itoh, S Horisawa
Ultrastructural aspects of bacterial attacks on an archaeological wood
1993 - IRG/WP 93-10007
Transmission electron microscopy of wood from a Chinese ship submerged in the mud for over 900 years showed bacteria to be the main factor for its deterioration. The micromorphology of degraded wood cell walls was similar to that observed during the attacks of wood by erosion bacteria. Other bacterial forms, previously considered lo be scavenging bacteria, were also abundant in degraded areas of t...
Yoon Soo Kim, A P Singh
Effect of permeability and extractives on the decay rate of southern pine sapwood in above grund exposure
2005 - IRG/WP 05-20310
The effects of wood permeability and hydrophilic and hydrophobic extractives on the decay rate of southern pine sapwood in above ground exposure were investigated. Permeability was determined by water sorption measurements, and the effect of extractives was studied by pre-extracting the test samples prior to outdoor exposure using water to extract hydrophilic extractives or sequential methanol/cy...
D D Nicholas, T Schultz, L Sites, D Buckner
The Relationship of Fiber Cell Wall Ultrastructure to Soft Rot Decay in Kempas (Koompassia malaccensis) Heartwoo
2004 - IRG/WP 04-10541
The ultrastructure of fiber walls in kempas (koompassia malaccensis) heartwood was examined in relation to soft rot cavity formation. The fibers consisted of middle lamella and thick secondary wall. The secondary wall was differentiated in to a S1 layer, and a unique multi-lamellar S2 layer. Two distinct forms of lamellae were recognisable, one type being considerably thicker than the other. They ...
A P Singh, A H H Wong, Yoon Soo Kim, Seung-Gon Wi
The use of TCMTB in applications other than sapstain prevention: A review
1990 - IRG/WP 3606
The efficacy of TCMTB against staining fungi and surface moulds has been thoroughly investigated during the last decade. As a result, the chemical is used as an alternative to the chlorinated phenols in various parts of the world for the preservation of freshly sawn timber. Less known are the data obtained against brown rot, white rot and soft rot fungi. The termite repellent and bactericidal prop...
R Van der Eynde
Isolation and identification of bacteria from degraded wood - A progress report
1986 - IRG/WP 192
During attempts to isolate tunnelling bacteria in pure culture, physical separation from other bacteria was successfully achieved by the use of cellophane. Cellophane was used in liquid cultures as a substrate for tunnelling bacteria that were present in a mixture with other bacteria. By tunnelling into cellophane, TB were physically removed from contaminating bacteria which could then be removed ...
J A Drysdale, P J Ruland, J A Butcher
Effect of mineral wools on growth and decay capacities of Serpula lacrymans and some other brown-rot fungi
1991 - IRG/WP 1481
The influence of stone wool and glass wool on growth and decay capacities of Serpula lacrymans and some other brown-rot fungi was studied. Mass losses of pine wood caused by Serpula lacrymans and Gloeophyllum trabeum were increased when stone wool was present. Glass wool had no influence on mass losses. Coniophora puteana, Serpula lacrymans and Gloeophyllum trabeum grew into stone wool and destroy...
L Paajanen, A-C Ritschkoff
Biodegradation of acetylated southern pine and aspen composition boards
1994 - IRG/WP 94-40020
This objective of this study was to investigate the influence of the acetylation treated wood fiber, Phenol-formaldehyde resin content level, two wood fiber species, three fungi species on the dimensional stability and decay resistence of high density composition boards. A standard ASTM method was used to evaluate weight loss and thickness change. The linear shrinkage and expansion of each species...
P Chow, T Harp, R Meimban, J A Youngquist, R M Powell
Natural durability of wood in ground contact - A correlation between field and laboratory tests
1985 - IRG/WP 2182
A field test is being carried out to evaluate the natural durability of 20 hardwoods. The resistance to decay and termite attack was evaluated in accelerated laboratory tests. The results of the field test after 6 years and 8 months indicate that there is not necessarily agreement between results from laboratory and field tests. It is pointed out that apart from the artificiality of the laboratory...
M S Cavalcante, G A C Lopez, R G Montagna, M E S Fosco Mucci
Positive dosage response of CCA in hardwood power poles to soft rot indicated from New South Wales soft rot survey dat
1983 - IRG/WP 3233
Experience and observation have shown that retentions of less than 16 kg/m³ in the sapwood of individual hardwood poles are unlikely to delay its deterioration sufficiently to ensure an economic performance in some instances. The higher retentions of current practice should do so subject to adequate inspection and maintenance. Increases in retentions requirements up to 35 kg/m³ more or less, dep...
A J Witheridge
Mapping soft rot decay distribution using image analysis
1993 - IRG/WP 93-20011
Image analysis has been shown to be a useful technique for the assessment of soft rot decay caused by Chaetomium globosum in birch and bamboo (Wickens and Murphy, 1992). The technique can permit assessment of decay in individual or small groups of cells and this has been used to undertake soft rot decay mapping in thin sections of bamboo. Assessments were made of the extent of soft rot decay with ...
P J Wickens, R J Murphy, G F M Watts
Inhibition of wood decay and termite damage by calcium precipitation
1996 - IRG/WP 96-30111
Fungal decay of wood in service, especially brown rot, results in billions of dollars (US) of losses annually. Recent environmental restrictions, both U.S. and international, are limiting or eliminating the use of broad spectrum biocides for wood preservation, primarily due to problems with disposal. In order to design new, environmentally benign methods for control of wood decay fungi, it is esse...
F Green III, T A Kuster, L Ferge, T L Highley
The effect of high temperature and long pressing time on the dimensional stability and decay resistance of OSB
2002 - IRG/WP 02-40237
The exterior use of OSB is restricted because when it is exposed to wet conditions swelling, loss of internal bond strength (IB) and decay occur. In this study an alternative process of pressing which results in the production of dimensionally stable and a more decay resistant strandboard was investigated. Boards were pressed at elevated temperatures for prolonged pressing cycles and their physi...
G J Goroyias, M D C Hale
Effects of artificial UV weathering and soft rot decay on heat treated wood
2005 - IRG/WP 05-40302
Oil and inert gas oven heat treated pine wood strips 100 µm thick were mildly heat treated (200°C, 30 mins linseed oil, 120 mins oven). Following treatment, specimens were exposed to UV weathering (300 hours) and decay by the soft rot fungus, Chaetomium globosum. The effects of each treatment were assessed by zero span tensile testing, microscopy and by FTIR.
Tensile testing of heat treated s...
M D C Hale, S C Ghosh, M J Spear
Effects of a formaldehyde and sulphur dioxide treatment on decay and mechanical properties of aspen waferboard
1983 - IRG/WP 3242
Aspen wafers were sequentially treated under vacuum with formaldehyde and sulfur dioxide gas and pressed into waferboard bonded with powdered phenol formaldehyde resin. Decay resistance and strength properties were determined before and after simulated weathering. The water resistance of the phenol bonding system was lost in board made from the gas-treated wafers. This white rot fungus Coriolus ve...
E L Schmidt
Relative performances of DNBP and CCA wood preservatives in accelerated decay tests
1988 - IRG/WP 3496
The effectiveness of 2-sec-butyl-4,6-dinitrophenol (DNBP) was compared with that of CCA. Test blocks of Pinus patula and Eucalyptus grandis were impregnated to precisely known retentions of approximately 3, 6, and 10 kg/m³ CCA and solvent-borne DNBP respectively. They were then challenged in decay tests comprising soil burial and exposure to monocultures of Chaetomium globosum, Coriolus versicolo...
W H Schnippenkoetter, L D Abraham, A A W Baecker
Examining environmental conditions and the biodeterioration of historic waterlogged wood: the Kolding Cog
2002 - IRG/WP 02-10441
Survival of waterlogged wood from thousands and in rare cases millions of years presents scientists with a unique opportunity to examine wood specimens which, due to select properties of the wood itself and/or the depositional environment, have not been completely degraded. This paper discusses the biodeterioration of a submerged shipwreck buried in Kolding Fjord, Denmark for the past 1000 years....
B A Jordan, D J Gregory, E L Schmidt
Movement and persistence of chloropicrin, Vapam, Dazomet and methylisothiocyanate in red and white oak timbers
1992 - IRG/WP 92-3728
This study describes the movement and persistence of four fumigants in sawn red and white oak timbers exposed out of ground contact for 2 years. Chloropicrin moved the furthest from the point of application, and was the most persistent. Vapam was next best, followed by Dazomet. Methylisothiocyanate (MIT), applied as pellets, was not effective, probably because MIT was lost from pellets prior to tr...
T L Highley