Your search resulted in 135 documents. Displaying 25 entries per page.
Resin bleed after light organic solvent preservative treatment - the effect of drying method and process type
1986 - IRG/WP 3378
The effects of drying method and treatment process type on resin bleed were investigated. High-temperature drying of resinous radiata pine (Pinus radiata D. Don) heartwood resulted in improved wood permeability, higher preservative uptake, and greater resin bleed when treated by the Rueping process. Resin bleed was reduced substantially when timber was treated by the Lowry process, and totally eli...
P Vinden
Polyflavonoid tannins - From a cause of CCA soft-rot failure to the "missing link" between lignin and microdistribution theories
1986 - IRG/WP 3359
Polyflavonoid tannins are proven to be fast-reacting with CCA solutions and hence, to be strong competitors of the structural wood constituents for fixation of CCA preservatives. The consequence of this effect is that even relatively small amounts of tannin cause severe undertreatment of the structural wood constituents which in turn badly affects the long term durability of CCA-treated timber. Th...
A Pizzi, W E Conradie, M Bariska
Soft rot decay of Eucalyptus maculata Hook. in different soils from Queensland, Australia
1980 - IRG/WP 1113
In the present work, different Queensland soils were chosen and their gross effects on the decay of treated and untreated Eucalyptus maculata examined. The soils were also amended with various levels of phosphate to study the response of the wood decay mycota to an increasing supply of this nutrient. Phosphate amendment was chosen because of the wide-scale use of superphosphate on Queensland soils...
L E Leightley, I W Russell
Defining fungal decay types - Final proposal
1988 - IRG/WP 1355
The term soft rot is proposed for all forms of decay caused by Ascomycetes and non-basidiomyceteous Fungi imperfecti. The terms brown rot and white rot should be used only for decay caused by Basidiomycetes. Brown rot is characterized by extensive depolymerization of the cellulose and limited lignin degradation. White rot is characterised by significant degradation of the lignin component in wood....
T Nilsson
Chapter 2 - Introduction to world bamboo
2007 - IRG 07-10635-02
In this chapter the bamboo species of the whole world along with local name, bamboo type, flowering
type, locality and uses have been presented in 20 different Tables....
A K Lahiry
Sludge formation in timber treatment with CCA preservatives. Origin and elimination
1984 - IRG/WP 3276
The exact distributions between lignin and holocellulose and retentions on wood of copper, chromium and arsenic as a function of various sets of conditions in a factorial experiment in which combinations of three temperatures of treatment, three CCA solution concentrations, four pH's of the initial CCA solution and two timber species, namely Pinus radiata and Eucalyptus grandis, are repor...
A Pizzi, W E Conradie, A Jansen
Screening of lignin peroxidase from white-rot fungi
1998 - IRG/WP 98-10274
Since lignin peroxidase was first found in the ligninolytic culture of Phanerochaete chrysosporium, it has been regarded as an enzyme responsible for the lignin biodegradation and studied comprehensively. As the results of these studies its unique characteristics have been revealed. On the other hand, the features of lignin peroxidase produced by other white-rot fungi have not been studied so much...
I Momohara
A comparative study of CCA type C and B treated poles in service
1993 - IRG/WP 93-50001-05
CCA K33 type B and C treated utility poles, 9 pieces of each treatment type, were analyzed for preservative retention after 11 years in use. Borings were taking 1 m above and 0.3 m below the ground line. Also total amount of copper, chromium and arsenic was determined in soil surrounding the poles. The solubility of these active components in soil was monitored by using different leaching procedur...
A J Nurmi
A study of decay type variability in variously treated Fagus sylvatica and Pinus radiata field test stakes exposed at a vineyard for 30 - 45 months
1998 - IRG/WP 98-10271
Pinus radiata test stakes were treated with 10 kg/m3 of CCA plus 4 lower retentions in a geometric series of 1.5. Fagus sylvatica was treated with 15 kg/m3 and 2 lower retentions. Both timber species were also treated with equivalent retentions of various new generation preservatives (P. radiata was also treated with creosote). Whilst these stakes were exposed at 11 sites in New Zealand (NZ) and 2...
R N Wakeling, A P Singh
Practical consequences of the clarification of the chemical mechanism of CCA fixation to wood
1983 - IRG/WP 3220
Practical consequences derived from the chemical investigation of the mechanism of fixation of CCA to the wood constituents are discussed. Among these, formulas for the calculation of the time of hexavalent chrome fixation are presented. Furthermore, three parameters are shown to be important to the long-term effectiveness of CCA-treated timber: (i) the temperature of treatment, (ii) the initial p...
A Pizzi
UV-microspectrophotometry of lignin and accessory compounds in wood cell walls of conifers
1999 - IRG/WP 99-20171
The distribution of lignin in the cell wall of conifer tracheids was determined by UV-VIS microspectro-photometer. Wood sections of one micron thickness were measured between the wavelength 240 and 700 nm. Spectral analyses revealed that the conifer lignin associated with the tracheid secondary wall and middle lamella is composed of guiacylpropane units which exhibit a characteristic UV absorption...
G Kleist, G Koch, J Bauch
Natural weathering of wood in a sunny climate effects on surface chemistry and paint adhesion
1997 - IRG/WP 97-20109
Radiata pine veneers and blocks were exposed to natural weathering under Australian summer conditions over a period of 30 days. Infrared spectroscopy revealed that there was perceptible surface delignification after 4 hours exposure, substantial surface delignification after 3 days exposure and almost complete surface delignification after 6 days. Viscometry determinations on holocellulose samples...
P D Evans, P D Thay, K J Schmalzl
Reaction of osmium tetroxide with a diphenolic compound as a model substance for demethylated lignin
1986 - IRG/WP 1303
By using caffeic acid as a model substance for diphenolic moieties of demethylated lignin it was found that electron dense particles called by the authors "osmiophilic particles" in former papers are reaction products of OsO4 with the model substance. By these products it is possible to indicate the enzymatic demethylation of lignin taking place during wood decay. The appearance of the electron de...
K Messner, E Srebotnik
Formation of soft rot cavities in relation to concentric layers in wood fibre walls
1983 - IRG/WP 1185
A large number of timber species attacked by soft rot have been examined using light microscopy. The S2 layers in a large number of the timbers exhibited special structural features in the form of thin concentric layers. Several observations indicate that these layers may be characterised as "weak" zones by being more easily degradable than the surrounding wall layers. The chemical structure of th...
T Nilsson, G F Daniel
Microbial breakdown mechanisms. Mini-Symposium at the 18th IRG meeting, Honey Harbour, Ontario, Canada
1987 - IRG/WP 1327
An understanding of how micro-organisms cause chemical alternation to wood is essential for effective wood preservation. Investigation of the Microbial Breakdown of wood is a very dynamic research field and is increasing in importance as several biocides are being examined as alternativesw to classic wood preservatives. These biocides often do not possess broad spectrum activity. It is esential th...
L E Leightley
Correlation between changes in colour and chemical composition during photo-degradation of wood surfaces
2005 - IRG/WP 05-40301
Changes in colour of wood (yellowing) during photo degradation or weathering reflect chemical changes in wood. Therefore, the relationship between changes in chemical composition and CIELAB colour parameters is very important to characterize photodegradation of lignocellulosic surfaces. In this study, the changes in chemical composition and yellowing due to photo-degradation was studied by expos...
K K Pandey
A study of the decay type potential of seven soils
1992 - IRG/WP 92-1539
The aim of this experiment was to determine the significance of the fungal inoculum potential and physico-chemical properties of five field trial test site soils, a garden compost known to cause white rot in copper treated fence palings, and soil from a zone between 2 and 15 centimetres from a CCA treated post with brown rot, in causing differential decay type in Pinus radiata and Poplus deltoides...
R N Wakeling
Effect of angle of exposure on degradation of radiata pine during weathering trials
1988 - IRG/WP 2301
The importance of angle of exposure on the degree of weathering of materials has not been adequately resolved. In conventional tests, specimens are exposed at an angle of 45° facing the equator, but more recently experiments on polymeric materials have suggested that an angle of 0° may be preferable since this angle maximises levels of received ultra-violet radiation. In this paper the degradati...
P D Evans
Distinguishing isolates of Aureobasidium on the basis of their ability to utilise lignin breakdown products as a sole carbon source
1996 - IRG/WP 96-10151
Wild isolates of Aureobasidium were obtained by dilution plating from a ca 20 year old painted pine window frame. Four isolates were obtained from the paint/wood interface region and four isolated from regions deep in the wood. The isolates were then used to inoculate liquid cultures containing ferulic acid, a lignin breakdown product, present as the sole carbon source. Ability of the isolates to ...
M W Schoeman, D J Dickinson
A technique for fructification and basidiospore production by Serpula lacrymans (Schum. ex fr.) SF Gray in artificial culture
1986 - IRG/WP 2255
A method for fructification and basidiospore production by Serpula lacrymans is outlined. A wheat flour/malt extract medium or an oat grain medium, enriched with alanine, tri-potassium phosphate and thiamine supported good fructification of the fungus at a temperature of 12°C. The influence on fructification of temperature, light and inoculum is discussed. To date, 22 stains from a total of 38 te...
S Cymorek, B M Hegarty
Soft rot decay in acetylated wood. Chemical and anatomical changes in decayed wood
2002 - IRG/WP 02-40231
Acetylated Beech (Fagus sylvatica) and Scots Pine (Pinus sylvestris) wood were studied in soil beds under laboratory conditions for longer periods. High mass losses and dynamic MOE losses were measured in non-acetylated wood and at lower weight percent gains (WPG). Rapid losses of lignin, holocellulose and ?-cellulose occurred in non-acetylated beech wood and no losses were detected at the highest...
B Mohebby, H Militz
The effect of extent and location of decay on strength loss in constructional timber
1994 - IRG/WP 94-30039
Radiata pine heartwood billets, 50 x 100 x 1000 mm³ were end-sealed and treated with copper-chrome-arsenate preservative (NZ Type I) to a range of retentions and penetration patterns. Cross-sections, 10 mm thick, were cut from the centre of each billet and used for determination of preservative distribution, for preservative analysis and for decay tests. The decay test consisted of laying samples...
M E Hedley, H Bier
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
Degradation of lignin model compounds with coordinated copper in the presence of peroxide
1998 - IRG/WP 98-10282
A novel diffusible system capable of decomposing lignin model compounds with copper, coordinators and peroxides has been proposed. When pyridine was used as a copper coordinator, two synthetic dyes, Poly-R and RBBR were intensively decolorized with Cu(II) and H2O2 in aqueous solutions at room temperature. Although reactions with Cu(II) and H2O2 produce a strong oxidant, hydroxyl radical, via a Fen...
K Koller, K Messner, T Watanabe
Quantification of wood decay effects by HPLC analysis
1992 - IRG/WP 92-1576
The present work quantified the effects of the white rot basidiomycetes Coriolus versicolor and Phanaerochaete chrysosporium, and also those of the brown rot fungi Coniophora puteana and Lentinus lepideus, on Pinus patula and Eucalyptus grandis. Wood colonisation was quantified by Kjeldahl nitrogen determinations converted to biomass assays, and degradation was quantified by weight losses produced...
V Singh, M Tarin, G D Shelver, A A W Baecker