Your search resulted in 189 documents. Displaying 25 entries per page.
CCA fixation experiments. Part 2
1989 - IRG/WP 3505
CCA fixation in wood was measured by both squeezing solution from treated wood that had not been dried and analyzing the solution for copper, chromium and arsenic, as well as using a chromotropic acid test to detect the presence of chromium VI. Both methods provide useful information on the CCA fixation process and illustrate that chromium VI disappears as CCA becomes fixed within wood....
W S McNamara
Testing of alkylammonium compounds
1981 - IRG/WP 2152
Following laboratory soil block tests which showed that Bardac 20 possessed a fungicidal threshold similar to that of chromated copper arsenate, treated ponderosa pine sapwood stakes were installed in a field test site near Vancouver, Canada. Two years after installation all the stakes show signs of fungal degradation. Seven stakes have been removed from the test due to total loss of strength afte...
J N R Ruddick
In-situ pressure injection for preservation of rubber wood (Hevea brasiliensis Muel Arg.)
1992 - IRG/WP 92-3688
Rubber wood is widely used for the manufacture of furniture, doors for housing and packing cases. However in an untreated condition it is highley susceptible to sapstain and decay fungi and borers. Its utility gets considerably reduced if the wood is not treated well in time. Preservative treatment has to be given within the period of felling and transport to prevent not only loss of structural pr...
H S Ananthapadmanabha, V R Sivaramakrishnan
Localization of oxalate decarboxylase in the brown-rot fungus Postia placenta
1996 - IRG/WP 96-10161
Oxalate decarboxylase, the enzyme that breaks oxalic acid down into formic acid and carbon dioxide, was recently detected in mycelial extracts of the brown-rot fungus Postia placenta. Differential centrifugation was used to demonstrate that the enzyme is loosely associated with the hyphal surface. Enzyme activity can be removed by washing the hyphae with a low pH buffer. Only low levels of activit...
J A Micales
Effect of fatty acid removal on treatability of Douglas-fir
1993 - IRG/WP 93-40008
Treatment of Douglas-fir with chromated-copper-arsenate (CCA) poses a major challenge. Several hypotheses based on the anatomical aspects as well as chemical reactivity of the preservative formulations with cell wall constituents and deposits have been proposed. Techniques to prevent pit aspiration or slow fixation reactions have, however, not significantly improved treatment. The presence of high...
S Kumar, J J Morrell
First draft of a monographic card for Fomitopsis pinicola (Fr.) Karst
1980 - IRG/WP 196
P W Perrin
Ground contact performance of wood treated by the MSU process
1990 - IRG/WP 3609
Environmental concerns have prompted a renewed interest in accelerated fixation schemes for CCA-treated wood. Results from stake tests of southern pine (Pinus sp.) treated using a conventional Bethell cycle are compared with matched stakes treated using the MSU Process. The effects of adding boric acid to the preservative formulation are also discussed. Differences among test plots are discussed....
H M Barnes, T L Amburgey, R W Landers
The formation of organotin carboxylates in bis(tributyltin) oxide - treated Pinus sylvestris sapwood
1990 - IRG/WP 3618
Tributyltin compounds have been successfully used for many years as wood preservatives, although their chemical nature in timber have not been fully elucidated. This study by 119Sn and 13C NMR spectroscopy has shown that, on impregnation into Pinus sylvestris sapwood, bis(tributyltin) oxide, (Bu3Sn)2O, is rapidly converted to tributyltin carboxylates, Bu3SnOCO·R, via reaction with components of t...
S J Blunden, R Hill
A novel lipid-related compound, (Z)-1,7-nonadecadiene-2,3-dicarboxylic acid, produced by white-rot fungus Ceriporiopsis subvermispora
2001 - IRG/WP 01-10411
Lipid peroxidation is a possible oxidative process of lignin-degradation at a site far from the enzymes by selective white rot fungi. Production and peroxidation of saturated and unsaturated fatty acids by Ceriporiopsis subvermispora strongly suggests involvement of lipid peroxidation in its ligninolytic system. In this paper, a new aliphatic lipid-related fungal metabolite was isolated from wood ...
M Enoki, Y Honda, M Kuwahara, K Messner, T Watanabe
Oxalic acid production of fifteen brown-rot fungi in copper citrate- treated southern yellow pine
2001 - IRG/WP 01-10388
Non-arsenical copper-based wood preservatives have grown in number since the 1980's as a response to environmental concerns posed by arsenicals. Interest in copper tolerant decay fungi has increased accordingly. Oxalic acid (OA) production by brown-rot fungi has been proposed as one mechanism of copper tolerance. Fifteen brown-rot fungi representing the genera Postia, Wolfiporia, Serpula,...
F Green III, C A Clausen
Differential behaviour of wood rotters at water repellent Rubberwood
2000 - IRG/WP 00-10386
Rubberwood samples treated with different concentration of aqueous solution of chromic acid has induced significant increase in water repellency and attains dimensional stability. Though water repellency and dimensional stability was achieved by treatment, the fungal invasion could not be completely controlled. Differential level of decay of brown and white rot in wood treated with water repellent...
H C Nagaveni, S S Chauhan, K S Rao
Iron in stone wool - one reason for the increased growth and decay capacity of Serpula lacrymans
1992 - IRG/WP 92-1537
The chemical compositions of stone wool and glass wool were analysed. There was more iron in the stone wool than in the glass wool. It was found that iron present in stone wool was easily dissolved by oxalic acid that Serpula lacrymans is able to produce. The stone wool promoted the decay of pine wood by Serpula lacrymans. The glass wool had no effect on the decay capacity of Serpula Iacrymans. Th...
L Paajanen, A-C Ritschkoff
The performance of water repellants on radiata pine exposed to the weather
1989 - IRG/WP 3553
The effectiveness and resistance to weathering of four water repellent treatments, a commercial timber stain, and an oil-based clear finish, was assessed using 20x20x6 mm³ samples of untreated, copper-chrome-arsenic (CCA)-treated, and tributyltin oxide (TBTO)-treated radiata pine exposed to the weather over a four month period. The water repellency of each preservative/water repellent combination...
D V Plackett, F M Cameron
Effects of Trichoderma harzianum on enzyme activity and oxalic acid production of Gloeophyllum trabeum in ponderosa pine sapwood blocks
1992 - IRG/WP 92-1550
The effect of a bioprotectant, Trichoderma harzianum, on the activity of Gloeophyllum trabeum was investigated using a wood wafer sandwich method. Wood weight loss was greatest with Gloeophyllum trabeum exposed wafers, intermediate with those exposed to both the bioprotectant and decay fungus, and lowest with the bioprotectant exposed wafers. Extracts of wood wafers after 2, 4, or 6 weeks of funga...
C M Sexton, J J Morrell
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
Sterilization of mango wood (Mangifera indica L.) without heat
1995 - IRG/WP 95-30065
Researches revealed that boric acid can play an important role for sterilizing wood instead of heating. Wet (green) mango boards (Mangifera indica L.) were pressure treated in treating cylinder at initial vacuum of 508 mm Hg for 15 minutes and impregnation pressure of 7 kg/cm² for 4 hours with 5% solution (w/v) of 1:1:1 commercial grade (95% pure) sodium dichromate, copper sulphate and boric acid...
A K Lahiry
The reliability of colouring methods for the determination of biflourides and boron in spruce wood
1994 - IRG/WP 94-20036
From practical reasons, qualitative spraying methods are widely used for the detection of bifluorides and boron in wood. The main aim of this research was to detect whether the concentration of the active ingredient in the coloured area is equal or greater than the toxic value against basidiomycetes. Both colouring methods, Z-A reagent for fluorides and curcuma reagent for boric acid, are a reliab...
R Grell, M G Sanders, W J Homan, H Militz
Oxalate production and calcium oxalate accumulation by Gloeophyllum trabeum in buffered cultures
1994 - IRG/WP 94-10075
Most basidiomycetous fungi produce oxalic acid as a result of their metabolic activities and nutrient procurement. There is currently a renewed interest in the role that oxalic acid may play in the decomposition of wood by basidiomycete fungi. It has been observed that although most wood degrading fungi have the capacity to produce oxalic acid, not all of these organisms express this capacity equa...
J H Connolly, J Jellison
Leaching results of shower test on L-joints with boric acid, bifluoride and TBTO rods
1995 - IRG/WP 95-50051
As part of the EC-project "Improvement of a local preservation process for wood products with reduced environmental impact", TNO has performed a leaching test on L-joints treated with pills with boric acid (Defence corner), bifluorides (Woodpil 55) and TBTO (Woodcap). The L-joints were exposed in an adapted shower test during 10 days, using 70 liters of water per day. The experiment is designed to...
P Esser, M J Boonstra, W L D Suitela, A J Pendlebury
Bioefficacy of boric acid grafted onto wood
1999 - IRG/WP 99-30202
The use of borate treated wood in outdoor is limited because of the migration of borate. The objective of this study is to investigate the fixation of boric acid in wood using polyethylene glycol (PEG-400) to form polyester borate and isocyanato group as coupling agent. FT-IR was used to monitor the reaction between boric acid and PEG. Elemental analysis was conducted to evaluate the C, H, and N v...
Weining Cui, D P Kamdem
Treatment of wood-based panel products with volatile borate
1990 - IRG/WP 3616
The paper presents recent developments in the use of volatile borate esters for the preservative treatment of wood based board materials. Several advances on previous reports are discussed. In laboratory studies, treatment times of approximately ten minutes at 20°C on boards at equilibrium moisture content provided full penetration and retentions of 1% wt/wt boric acid. Biological tests have been...
P Turner, R J Murphy, D J Dickinson
Identification of terminal structures in cellulose degraded by the brown-rot fungus Postia placenta
1989 - IRG/WP 1389
To gain insight into the biochemical mechanism employed by brown-rot fungi to depolymerize cellulose, we identified the end-groups of chemically pure cellulose that had been depolymerized by the brown-rot fungus, Postia placenta. The depolymerized cellulose was acid hydrolyzed and the anion fractions isolated by ion chromatography. Sugar acids were identified by gas chromatographic and mass spectr...
T K Kirk, T L Highley, R E Ibach, M D Mozuch
Efficacy of linear chain carboxylic acid anhydrides as wood protection chemicals
2002 - IRG/WP 02-30295
This paper presents an assessment of the effectiveness of linear chain carboxylic acid anhydrides namely, acetic, propionic, butyric, valeric and hexanoic anhydride, in improving the decay resistance of Corsican pine (Pinus nigra Schneid) sapwood. Wood-anhydride bond formation was verified by the increase in sample weight and volume. A brown rot fungus
[Coniophora puteana (Schum.:Fr)] was selec...
A N Papadopoulos, M D C Hale, C A S Hill
Treatment of wood with formaldehyde. Acid catalysis of the reaction between formaldehyde and wood
1980 - IRG/WP 3146
Formaldehyde reacts with the free OH-groups in wood forming cross-linking bonds. The reaction can be brought about without any catalyst but in that case the activation energy is very high and high temperatures and long reaction times are needed. Normally, the reaction is catalysed by different acids. Acid catalysts, however, tend to degrade the cellulose and the wood matrix causing reduction in th...
T Vihavainen, K Piispanen, P Mansikkamäki
Summaries of two Russian papers received from Professor Dr. D.A. Belenkov and V.A. Seletskaya of the Ural Forest Engineering Institute, Sibirsky Trakt, 37, Sverdlovsk, USSR, on the toxicity to Coniophora cerebella of salts of hydrofluoric acid and some fluoroborates
1977 - IRG/WP 298
1) Evaluation of the toxicity of some salts of hydrofluoric acid against the house cellar fungus (Coniophora cerebella Schroet)
Data are presented on the method of probability evaluation of the toxicity of the fluorides of sodium, ammonium, potassium, zinc and iron. On the retention of fluorine in wood all salts, except iron, possess practically equal toxicity at the standard level of the probability of the protection of the wood - 0.95 . There is good agreement between the analytically and graphically determined dose level. Evidence is given for dose variabitility, probabilities of wood protection at 0.5 and 0.95, the curve of efficacy - activity and the construction of the empirical probit graph.
2) Investigation of the toxicity of some borofluorides towards the house cellar fungus
Probability evaluation of the toxicity of borofluorides against the cellar fungus, and probit analysis evidence show that toxicity decreases in the sequence sodium borofluoride, copper borofluoride, tributyltin borofluoride. The effectiveness of protection method is able to evaluate the amount of fluorine and boron required in the wood.
C Grant