Your search resulted in 75 documents. Displaying 25 entries per page.
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
Preliminary studies of the performance of iron chelators as inhibitors of brown rot (Coniophora puteana) attack
1996 - IRG/WP 96-10185
This paper describes experiments to examine the proposal that the presence of iron is essential for brown rot fungi to utilize hydroxyl radicals remote from the hyphae as a means of converting the wood into a food source. reliminary test results are presented from trials using three different iron chelators impregnated into Scots pine (Pinus sylvestris) sapwood blocks. Their relative effects on th...
E D Suttie, R J Orsler, P M Wood
Recent development in North American industrial wood preservation plants
1988 - IRG/WP 3467
After remaining static for many years there have been a number of changes in plant design and treating cycles in recent years. This has been particularly true in the USA where few restrictions are placed on plant treating cycles by specifications; since only results type specifications are used. It is also important to realize that the AWPA Specifications for Southern Yellow Pine only call for tre...
J F Bridges
Extracellular hydrogen peroxide-producing and one-electron oxidation system of brown-rot fungi
1990 - IRG/WP 1445
Wood-component-degrading compounds involved in the initial degradation of the cellulose and lignin in wood were isolated from wood-containing culture of brown-rot fungi, Gloeophyllum trabeum and Tyromyces palustris and partially purified by gel filtration on Sephadex G-25 and DEAE-Sepharose ion-exchange chromatography. The compounds were glycoproteins. The molecular weights of the glycoproteins as...
A Enoki, S Yoshioka, H Tanaka, G Fuse
Targeted inhibition of wood decay fungi: degradation of cotton cellulose
1999 - IRG/WP 99-10321
Brown-rot decay is responsible for 80% of the damage and replacement of wood in service. For nearly thirty years, researchers have postulated a one-electron oxidase system combining Fe+2 oxalic acid, and H2O2 in the production of hydroxy radicals which ultimately oxidize cellulose in situ. Recently, researchers have been investigating antioxicants, in combination with biocides (Schultz, et al.,199...
F Green III, T A Kuster
Experiments on the degradation of tributyltin oxide: A progress report
1984 - IRG/WP 3287
A variety of experiments designed to assess the chemical and physical factors affecting the degradation of tributyltin oxide in treated timber are described. Simple procedures in which temperature and oxygen availability were increased in the presence of wood and water suggest that the wood itself was of prime importance. Attempts to decrease degradation with antioxidants were unsuccessful but led...
R J Orsler, G E Holland
The effect of a chelator mediated fenton system on activation of TMP fibres and decolorization of synthesized dyes
2004 - IRG/WP 04-50223
The purpose of this work is to improve our current knowledge of the non-enzymatic mechanisms involved in the brown rot degradation of wood, but also to study the potential applications of a chelator-mediated Fenton system in activation of wood fibers and decolorization of synthesized dyes. In this work, Electron Spin Resonance (ESR) spin-trapping techniques were used to study the generation of hyd...
Yuhui Qian, B Goodell, J Jellison
Studies of the mechanism of chromated-copper preservative. Fixation using electron spin resonance
1992 - IRG/WP 92-3701
Two softwoods and one hardwood species were treated with chromium trioxide, copper sulphate, chromated-copper wood preservative (CCA). The treated wood samples were analyzed during fixation by electron spin resonance (ESR). ESR spectra indicated that more than one Cr(V) species was generated from Cr(VI) soon after CCA treatment. The Cr(V) signal became strong within increased several hours followe...
K Yamamoto, J N R Ruddick
The lasting dehydration of wood treated by bifluorides worked up in Diffusec noticed by a continual drying of the wood
1999 - IRG/WP 99-30196
After an immersion of sound wood in a solution of Diffusec, in which a combination of acid potassium and ammonium bifluorides = FHF- in dissociated form is present, their potassium and ammonium fluoride ions together with the bifluoride ion = (FHF-) diffuse into the wood. They make use of the woodmoisture available as O-H-O bonds directly attached to the cellulose in the wood fibres to attract the...
H F M Nijman
Wood and filter paper degradation, phenol oxidase and one-electron oxidation activities by the white rot fungus Ceriporiopsis subvermispora
2003 - IRG/WP 03-10486
The activities of one-electron oxidation and phenol oxidase during incubation of cultures of the white-rot basidiomycete Ceriporiopsis subvermispora containing either glucose or wood were periodically measured. Further, the degradation activities against wood and filter paper were examined during the course of cultivation. Weight losses of Japanese beech wood and Japanese cedar wood after 12 wee...
H Tanaka, S Itakura, A Enoki
Some fundamental thoughts on the prediction of field performance from lab-testing based on comparison of lab and field test results of some copper-free materials
2003 - IRG/WP 03-20269
In the paper results from lab testing (ENV 807 and EN 113) are compared with field results (EN 252) of differently treated wood. Depending on the type of the organic biocide containing material and depending on type of soil and type of decay differences were found in suitability of the lab methods to predict field performance. The attempt is made to interpret the found differences. Furthermore it ...
A O Rapp, U Augusta
The involvement of extracellular substances for the generation of hydroxyl radical during wood degradation by white-rot fungi
1997 - IRG/WP 97-10218
The activities of one-electron oxidation, hydroxyl radical generation, and phenol oxidase during the incubation of cultures of four white-rot fungi containing either glucose or wood were periodically measured. Further, their degradation activities against wood were examined during the course of cultivation. The generation of hydroxyl radical was correlated to the activity of wood degradation and i...
H Tanaka, S Itakura, A Enoki
Further steps in the development of above ground wood preservative systems
2002 - IRG/WP 02-30300
Metal and organo-metallic wood preservative systems have provided the consumer with cost effective wood preservative systems which satisfy the performance requirements in a wide range of end uses.
With increasing environmental and legislative control, metal-free formulations have emerged as the dominant preservative systems for the protection of timber in the lower hazard classes.
In higher ha...
P Warburton, A S Hughes
Degradation of resin constituents in various wood species by the white rot fungus Bjerkandera sp. strain BOS55
1999 - IRG/WP 99-10301
In previous studies, the white-rot fungus Bjerkandera sp. strain BOS55 was shown to cause extensive degradation of lipophilic extractives (resin) in Scots pine wood. Further research was carried out in order to investigate the ability of Bjerkandera sp. for reducing resinous constituents in various softwood (Douglas fir, larch and spruce) and hardwood species (birch, beech and poplar). The greates...
J Dorado, T A Van Beek, F W Claassen, R Sierra-Alvarez
A model for attack at a distance from the hyphae based on studies with the brown rot Coniophora puteana
1995 - IRG/WP 95-10104
In timber infested by brown rot fungi, a rapid loss in strength is attributed to production of hydroxyl radicals (HO·) at a distance from the hyphae. The immediate precursor is Fenton's reagent (Fe(II)/H2O2), but the pathways leading to Fe(II) and H2O2 have remained unclear. Cellobiose dehydrogenase, purified from cultures of Coniophora puteana, will couple oxidation of cellodextrins to ...
S M Hyde, P M Wood
Bethoguard; A new wood protecting fungicide for use in metal free ground contact wood preservatives
2002 - IRG/WP 02-30301
Research has identified the limitations in both the spectrum of activity and permanence of organic biocides placed in wood in high hazard environments, particularly in the absence of heavy metals such as copper. More specifically, the control of soft rot decay in wood in soil contact has proven to be most problematic.
The new organic biocide, Bethoguard; an oxathiazine, has demonstrated excellen...
S C Forster, G R Williams, M Van Der Flaas, M Bacon, J Gors
Kinetics and mechanism of fixation of Cu-Cr-As wood preservatives. Part 4: Conversion reactions during storage
1974 - IRG/WP 332
Precipitates simulating those produced in wood by preservative fixation reactions were prepared by the reduction of Boliden K 33 and Celcure AP solutions with hydrogen peroxide and hydrazine. The pH changes on aging at 20 and 50°C were studied and related to the chemistry of fixation previously described. Hydrolysis of copper arsenates may render arsenic acid temporarily water soluble pending pre...
S-E Dahlgren
PXTS; A Metal Free Oligomer Wood Preserving System - A Summary of Data To Date
2004 - IRG/WP 04-30350
The world is continually looking for new wood preservative technology, especially to address environmental concerns. Recent changes in the USA have limited the use of arsenical containing formulations to industrial use through a negotiated voluntary cancellation of most residential label uses. PXTS (Polymeric Alkylphenol Polysulfide) offers a brand new technology that is an all organic system, lik...
M H Freeman, D D Nicholas, D Renz, R Buff
The bacterial transformation of organic biocides; a common mechanism?
2006 - IRG/WP 06-10585
It was found that a number of unformulated organic biocides showed a susceptibility to degradation by proteobacteria. Exposure of tebuconazole, a candidate biocide, chlorothalonil and IPBC to a Ralstonia strain was found to result in biocide detoxification, as demonstrated through HPLC and a bioassay. Exposure of the biocides to a previously identified extracellular factor was also found to resu...
D F Wallace, D J Dickinson
Isolation and characterization of hydroxyl-radical-producing glycopeptide genes from the white-rot basidiomycete Phanerochaete chrysosporium
2006 - IRG/WP 06-10588
During wood decay, the white-rot basidiomycete Phanerochaete chrysosporium secretes low-molecular-weight glycopeptides that catalyze a redox reaction between O2 and electron donors to produce hydroxyl radical. This reaction accounts for most of the hydroxyl radical produced in wood-degrading cultures of P. chrysosporium. In combination with phenol oxidases, hydroxyl radical is believed to play a r...
H Tanaka, G Yoshida, Y Baba, K Matsumura, S Itakura, A Enoki
Paintability and gluability of wood treated with arsenic-free and chromium free preservative treatments
2006 - IRG/WP 06-40342
The objective of this project was to study, in comparison with traditional CCA treatment, the paintability and gluability of wood treated with arsenic-free and chromium-free preservative treatments.
Four formulations, all certified CTB P+, were selected in accordance with their representativeness of the preservative product market: one CCA reference formulation and three chromium and arsenic free...
L Podgorski, G Legrand
Arsenic removal by plant pumping mechanism from arsenic solution using activated aluminum oxide as adsorbent – a preliminary study
2006 - IRG/WP 06-50239
This study evaluated the performance of plant pumping mechanism for removal of arsenic from arsenic solution using activated aluminum oxide as adsorbent. Generally, plants absorb water from soil mainly by osmosis process and toxic elements present in soil also move along with water. To remove toxic elements present in contaminated soils/water, different chemical substances are widely used as
...
B Tarakanadha, H Koyanaka, T Hata, Y Imamura
Phenol oxidase activity and one-electron oxidation activity in wood degradation by soft-rot deuteromycetes
2007 - IRG/WP 07-10615
Wood degradation, one-electron oxidation activity as assayed by ethylene generation from 2-keto-4-thiomethylbutyric acid (KTBA), and phenol oxidase activity were measured in cultures of six deuteromyce fungi, with glucose or wood as the carbon source. The four fungi that degraded Japanese beech wood had higher one-electron oxidation activities in wood-containing cultures than in glucose-containing...
H Tanaka, M Yamakawa, S Itakura, A Enoki
The characteristics of biodegradation mechanism of gamma-irradiated wood
2007 - IRG/WP 07-20352
Gamma radiation, as an easy, fast and effective sterilisation method, changes molecular structure in pest’s living cells, but also in wooden cell walls. Radiation-induced depolymerisation causes significant changes in wood properties crucial for laboratory testing of wood-preservative effectiveness. Natural durability of wood against rot fungi in lab conditions dependency on different sterilisat...
R Despot, M Hasan, F Pohleven, M Humar, G Rep
Methods for Determining the Role of Extractives in the Natural Durability of Western Redcedar Heartwood
2007 - IRG/WP 07-20356
The durability of western redcedar heartwood is influenced by a number of different extractives operating by different mechanisms. In order to guide a systematic isolation of extractives with high fungal toxicity, a micro-bioassay has been developed for measuring the fungal toxicity of extractive fractions. Two additional assays quantify the anti-radical and metal chelating properties of cedar ext...
R Stirling, C R Daniels, J E Clark, P I Morris