Your search resulted in 251 documents. Displaying 25 entries per page.
Wood degradation mechanisms by the brown rot fungus Gloeophyllum trabeum
1997 - IRG/WP 97-10229
A mechanism for the degradation of wood by the brown rot fungus Gloeophyllum trabeum is outlined. The mechanism includes the function of redox-cycling, low molecular weight phenolic derivatives which sequester and reduce iron in acidic environments. The role of oxalate for the sequestration of iron (hydr)oxides and the pH dependent transfer of iron to the G. trabeum phenolic chelators, as well as ...
B Goodell, J Jellison
Bifenthrin, a new insecticide for the control of termites and wood-boring insects
1995 - IRG/WP 95-30076
Bifenthrin, a new insecticidal compound Bifenthrin has been extensively tested, to determine its potential use to control termites and other wood destroying insects. Bifenthrin is effective at extreme low rates which can minimize human and environmental exposure to the product. Results of tests carried out by several research institutes and by FMC in different countries will be presented. The phys...
G Rustenburg
Chemical analysis for TBTN in LOSP-treated wood and preservative fluids
1994 - IRG/WP 94-20027
Tributyltin napthenate (TBTN) is being substituted for tributyltin oxide (TBTO) in LOSP preservative formulations because its lower reactivity/better stability allows co-formulation with synthetic pyrethroids. Better stability may reduce molecular degradation both in-service and during analysis. It was considered necessary to check whether TBTO analysis methods were suitable for use on TBTN treate...
D P Wraight, M J Kennedy
The distribution of introduced acetyl groups and a linseed oil model substance in wood examined by microautoradiography and ESEM
2000 - IRG/WP 00-40169
Microautoradiography, a photographic method that shows the localization of substances labelled with radioactive isotope, and Environmental Scanning Electron Microscopy (ESEM) were combined to enhance sensitivity, resolution and reliability for examination of the distribution of introduced substances in wood. The preparation of microautoradiographs is less complicated when investigated with ESEM an...
M Rosenqvist
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
Chemical analyses of IRG/COIPM INTERNATIONAL MARINE TEST (to determine the effect of timber substrate on the effectiveness of water-borne salt preservatives in sea-water) samples
1987 - IRG/WP 4114
Chemical analysis of CCA and CCB treated timber was carried out after exposure at tropical and temperate marine sites. Results indicated that losses of all elements had occurred. In particular, losses of boron were severe. Arsenic and copper were also lost. The chromium components in both formulations was the most dominant metal remaining. The results suggest that chromium modification was importa...
L E Leightley
A potential anti-sapstain chemical for sawmills
1984 - IRG/WP 3300
Several biocidal formulations were tested under laboratory conditions in order to discover an alternative antisapstain chemical to chlorophenoxides. The formulations tested were experimental water solutions containing a quaternary ammonium chloride, a commercial fungicide and/or a sodium salt of some carboxylic acids. The effect of sodium carbonate and borax decahydrate in mixture with a quaternar...
I A Linderborg
Chemical Analysis of Southern Pine Pole Stubs Thirty-Nine Months Following Treatment with Three Methylisothiocyanate-Based Fumigants
2004 - IRG/WP 04-30349
Agricultural fumigants have been commercially used in the United States for over 20 years to control internal decay in utility poles and other wooden structures. Of the four fumigants which are currently used in the remedial treatment of utility poles, three are based on methylisothiocyanate (MITC) as being the principal fungitoxic component. Two of these MITC-based fumigants, liquid metham sodi...
R J Ziobro, J Fomenko, D J Herdman, J Guzzetta, T Pope
The chemical analysis and biological evaluation of wood extractives as potential timber preservatives
1995 - IRG/WP 95-30090
Work involved the biological performance of water and organic solvent soluble extractives of four naturally durable wood species, namely; Matumi, Tamboti, Sneezewood and the Turpentine tree. These timber species are known to be naturally durable against termites and fungi (±25 to 35 years). The extractives were evaluated against termites and fungi using impregnated pine pencil stakes in field tes...
P Turner, D Conradie
Vapour boron treatment of wood based panels: Mechanism for effect upon impact resistance
1994 - IRG/WP 94-40036
Samples of medium density fibreboard, chipboard and oriented strandboard (OSB) were treated to two retentions of boric acid by a vapour phase treatment. The results of a range of mechanical tests were reported by Hashim et al. (1992, 1993) in which a small reduction in impact resistance was observed. Several investigations were carried out to study how and where this loss in impact resistance occu...
R Hashim, R J Murphy, D J Dickinson, J Dinwoodie
Chemical, physical and biological factors affecting wood decomposition in forest soils
2003 - IRG/WP 03-20281
Organic matter (OM) decomposition is an important variable in determining the potential of forest soils to sequester atmospheric CO2. Studies using OM from a particular location gives site-specific decomposition information, but differences in OM type and quality make it difficult to compare results among soils and forest ecosystems. By using a “standard” OM in decomposition studies, OM qual...
M Jurgensen, P Laks, D Reed, A Collins, D Page-Dumroese, D Crawford
Evaluation of chlorpyrifos as an insecticidal component of a wood preservative
1984 - IRG/WP 3301
After two years of laboratory and field testing, chlorpyrifos is showing excellent potential as an insecticidal treatment to wood. In laboratory termite tests, retentions as low as 1-2 parts-per-million or approximately 0.0008 kg/m³ (0.00005 lbs/ft³) are effective against the Coptotermes formosanus. Laboratory leaching tests have shown no significant effect on the concentration of the retained c...
K Rose, J Kozuma, P Sparrow
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
The case for non-chemical termite barriers in termite control
1989 - IRG/WP 1381
A brief outline of current non-chemical barriers in subterranean termite control and their use in Australia is presented. Recent use of non-chemical barriers in Hawaii has led to their evaluation in termite control here and elsewhere. In Australia, preliminary laboratory and field experiments have shown similar results to those found against Coptotermes formosanus in Hawaii, namely, Australian Cop...
J R J French
Microscopical analysis of formaldehyde-acid modified wood
1981 - IRG/WP 3182
Cross-linking of wood with gaseous formaldehyde improves its hygroscopic and dimensional behaviour, and its resistance against micro-organisms. However, formaldehyde cross-linking reactions take place only in the presence of an acid catalyst, which results in losses in mechanical By optimization of a formaldehyde-sulfur dioxide vapour phase process the reaction conditions were established to limit...
M Stevens, N Parameswaran
The chemical nature of bis(tributyltin) oxide in Pinus sylvestris sapwood
1989 - IRG/WP 3508
Tributyltin compounds have been used for many years as wood preservatives. This study has provided, for the first time, an explanation for the previously reported dealkylation and/or volatilisation of the tributyltin species in, and from, Scots pine (Pinus sylvestris) sapwood. Thus, 119 Sn nuclear magnetic resonance studies have shown that, on impregnation into this timber, bis(tributyltin) oxide ...
S J Blunden, R Hill
Chemical and biological studies of organotin treated and painted wood stakes after outdoor exposure
1987 - IRG/WP 3419
Organotin based wood preservatives containing tributyltin oxide (TBTO) or tributyltin naphthenate (TBTN) are used in Sweden mainly for double-vacuum treatments of window joinery of Pinus sylvestris. After impregnation the joinery is painted or stained in different colours. To evaluate this effect (different colours on the degree of degradation of TBTO and TBTN, effected by different temperatures i...
M-L Edlund, B Henningsson
Improving the weather resistance of glue-laminated jarrah and karri
1994 - IRG/WP 94-40017
Surface modification and dimensional stabilisation significantly increased the dry and wet shear strength of karri and jarrah lap-shear specimens (laminates) bonded with resorcinol formaldehyde. The combination of surface modification (sanding/sodium hydroxide treatment), and furfurylation produced the highest dry and wet shear strengths. Acetylated laminates had the lowest dry bond strength, but ...
J Balfas, P D Evans
An evaluation of chemical treatments for the protection of radiata pine logs from fungal degrade
1986 - IRG/WP 3377
Busan 30, Busan 1009, Mitrol PQ375. and sodium pentachlorophenoxide (NaPCP) plus have been evaluated as antisapstain treatments for the long-term protection of debarked radiata pine logs. After 3 months' winter-spring storage, treated debarked logs had less surface and internal sapstain than 'control' logs. After 6 months' storage all logs had internal sapstain ...
J A Drysdale, M E Hedley, J A Butcher
Treatability problems - Relationships between anatomy, chemical composition and treatability
2001 - IRG/WP 01-40213
This report documents the results of phase 1 and 2 of a 3-phase research program. In phase 1, two hundred and fifty-six (256) Southern pine (pinus spp.) nominal 2 x 6's (38 mm x 140 mm) from a single mill in Georgia (southeastern US) were evaluated for treatability with CCA preservative. After treatment, 128 pieces representing a broad range of treatment characteristics were selected and ...
J E Winandy, F Green III, D Keefe
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 suggestion for the improvement of the chemical protection of wooden poles
1987 - IRG/WP 3445
Insufficient drying of white poles in Sweden causes inadequate penetration of the impregnation compounds, CCA salts and creosote, in a varying proportion of the treated poles, and with pretreatment decay present, sooner or later, internal fungal attack in the ground-line zone of the standing poles is the result. The application of a diffusing fungicide in the ground-line zone in connection with th...
H Friis-Hansen
Properties of hot oil treated wood and the possible chemical reactions between wood and soybean oil during heat treatment
2005 - IRG/WP 05-40304
Thermal treatment with hot oil as the heating media based on the original idea from oil-heat treatment in Germany was investigated. The treatment was mainly carried out at 200ºC and 220ºC for 2 hours and 4 hours, and the wood species were mainly spruce and fir. This paper focuses on the difference between soybean oil and palm oil and the possible chemical reactions between wood and soybean oil. ...
Jieying Wang, P A Cooper
Preliminary studies of the decay mechanism of some brown-rot fungi
1989 - IRG/WP 1402
The importance of the enzymatic degradation of hemicellulose and cellulose by brown-rot fungi is still under discussion. Endo-ß-1,4-xylanase and endoglucanase activities of Coniophora puteana and Poria placenta cultures were measured by the increase in reducing groups. Enzymes were produced in liquid and solid sawdust based culture media. Enzyme activities were measured in two, four and eight wee...
A-C Ritschkoff, H Viitanen