Your search resulted in 59 documents. Displaying 25 entries per page.
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
Influence of aliphatic acids on spore germination of wood decay fungi
1984 - IRG/WP 2224
Influences of eight saturated fatty acids (C5-C10, C12 and C16) on spores of four isolates of wood decaying basidiomycetes (white rot fungi: Poria tenuis and Trametes hispida; brown rot fungus: Gloeophyllum trabeum [two isolates]) were observed in-vitro. Spore response after 24 hr on malt extract agar containing 10, 10² , or 10³ ppm of each fatty acid included: no effect on normal germination, d...
E L Schmidt
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
Screening of fungal strains for wood extractive degradation
1998 - IRG/WP 98-10254
Fungal strains were screened for their ability to degrade apolar extractives in wood from scots pine. The degradation of total wood extractives by 91 different strains was monitored in stationary batch assays incubated for 6 weeks. The results obtained show that the ability of wood-inhabiting fungi to utilize wood extractives varied greatly, even for different isolates of the same species. Fungal ...
J Dorado, M J Martinez-Inigo, T A van Beek, F W Claassen, J B P A Wijnberg, R Sierra-Alvarez
Wood preservation by a mixed anhydride treatment: Using simple models of polymeric wood compounds
2008 - IRG/WP 08-30457
Treatment of wood by a mixed aceto/oleic (or other fatty acid residue) anhydride promoted as a safe and environment friendly wood preservation system has been examined quantitatively by liquid phase 13C NMR and solid phase MAS-DEC (proton decoupling) 13C NMR through all its different stages to determine which reactions occur with simple model compounds of the polymeric constituents of wood. The p...
F Lyon, M-F Thevenon, A Pizzi, G Tondi, A Despres, J Gril, S Rigolet
Above Ground Field Evaluation and GC-MS Analysis of Naturally Durable Wood Species
2012 - IRG/WP 12-10764
Nine wood species are being evaluated in above ground field studies in Mississippi and Wisconsin. Candidate naturally durable wood (NDW) species are being rated at yearly intervals for resistance to decay, cupping, and checking. Field ratings after 12 months exposure are presented. To date, Paulownia tomentosa (PAW) and southern yellow pine (SYP) are least durable and cedars are the most durable i...
G T Kirker, A B Blodgett, S T Lebow, C A Clausen
Application of suberin fatty acids extracted from birch bark for wood coating
2021 - IRG/WP 21-40914
It is well known that chemical modifications to improve decay resistance also reduce the equilibrium moisture content (EMC) of wood. The mechanism of this action, however, has been the subject of much debate. Several groups have suggested that decay resistance is a result of lower diffusion rates of fungal degradation agents through the wood cell wall. A recent paper explained the fundamental prin...
A Kumar, Risto Korpinen, Veikko Möttönen
Biological assessment of bio-based phase change materials in wood for construction applications
2022 - IRG/WP 22-40935
Solid wood can serve multi-functionality for energy savings in buildings. The study reveals the results of bio-deterioration and degradation of solid Scots pine wood used to incorporate single or multicomponent fatty acid mixtures as bio-based phase change materials (BPCMs). The sapwood samples were impregnated with capric acid (CA), methyl palmitate (MP), lauryl alcohol (LA) and a mixture of coco...
S Palanti, A Temiz, G Köse Demirel, G Hekimoğlu, A Sari, M Nazari, J Gao, M Jebrane, T Schnabel, N Terziev
Preliminary study of the fungicidal and structural variability in copper naphthenates and naphthenic acids
1996 - IRG/WP 96-30114
Copper naphthenates, an oil-borne wood preservative listed by the American Wood-Preservers' Association (AWPA), is manufactured by complexing copper(II) with naphthenic acids. Prior to AWPA listing as a wood preservative, field experiments showed that copper naphthenates generally had good stability and were active against wood-destroying organisms. Recently, however, there have been reports ...
T Schultz, D D Nicholas, L L Ingram Jr, T H Fisher
Durability of larch (Larix spp.) wood against brown-rot fungi
1997 - IRG/WP 97-10228
Durability of the heartwood of Larix decidua, L. sibirica, L. gmelinii, L. gmelinii var japonica, L. gmelinii var olgensis and L. sibirica x decidua against brown rot fungi Coniophora puteana, Poria placenta and Gloeophyllum trabeum was tested according to EN 113 test method. Parallel samples were used to study the amount and composition of wood extractives. The sample trees originated from the re...
H Viitanen, L Paajanen, P Saranpää, P Viitaniemi
Addendum to Document No: IRG/WP/428
1977 - IRG/WP 437
A J Emery
An investigation into the stability of TBTO in LOSP-treated radiata pine
1987 - IRG/WP 3459
Nuclear magnetic resonance (NMR) spectroscopy and reverse phase paper chromatography were used to characterise the organotin compounds found in radiata pine treated with bis (tri-n-butyl) tin oxide (TBTO). Preliminary results indicate that the preservative is remarkably unstable in wood after light organic solvent preservative (LOSP) treatment. Significant decomposition of TBTO occurs in a matter ...
K J Archer, R Meder
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
Susceptibility of angiosperm sapwood to white-rot fungal colonization and subsequent degradation: a hypothesis
1997 - IRG/WP 97-10211
It has long been recognized that angiosperm sapwood in nature is relatively easily and preferentially degraded by white-rot fungi. This susceptibility to white-rot fungi is generally believed to be mainly caused by the structure and concentration of angiosperm lignin. However, an explicit explanation as to why lignin structure makes a particular wood vulnerable to white-rot colonisation and subseq...
T Schultz, D D Nicholas
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
The use of ESR spectroscopy to assess the photostabilising effects of wood preservatives
2000 - IRG/WP 00-20186
The degradation of wood surfaces exposed to UV light which leads to poor performance of clear coatings is understood to be due to delignification via a mechanism involving free radicals. Certain wood preservatives most notably CCA are able to photostabilise wood and therefore they may reduce the concentration of free radicals formed when treated wood is exposed to ultraviolet light. As a first ste...
S Schmid, R D Webster, P D Evans
Generation of hydroxyl radical by the brown-rot fungus, Postia placenta
1988 - IRG/WP 1360
In an electron spin resonance (ESR) survey of various liquid cultures and wood slivers innoculated with the brown-rot fungus, Postia placenta, the spin trap dimethyl-l-pyrroline N-oxide (DMPO) was used to detect the presence of the hydroxyl radical. The ESR spectra for the paramagnetic DMPO- hydroxyl radical adduct was observed in (1) nitrogen-limited, liquid cultures having 1.0% glucose or 0.1% c...
B Illman, D C Meinholtz, T L Highley
Solvent extraction of CCA-C from out-of-service wood
1998 - IRG/WP 98-50107
Elimination of CCA from decommissioned wood prior to disposal is a major environmental issue. One approach is to extract CCA from treated wood, then reuse the 'clean' (may contain CCA, but below hazardous level) wood materials for manufacturing wood-based composites. In the present paper, we focus on effective leaching processes, selection of leaching agents and optimum leaching ...
K M F Kazi, P A Cooper
A preliminary comparison of GC, HPLC and ELISA analysis of resin acids in pulp mill effluents
1997 - IRG/WP 97-20120
Resin acids are naturally occurring diterpenoid carboxylic acids present in most Canadian softwoods. There are eight common resin acids that are classified into two groups; the abietanes and the pimaranes. During processing of wood products they can be released into the environment where they are of concern because of their acute toxicity toward fish and other aquatic life. Traditionally resin aci...
A N Serreqi, K Stark, Xiumei Feng, J N Saddler, C Breuil
Influence of carboxylic acids on LEACHING of copper amine based preservatives
2005 - IRG/WP 05-30365
The importance of chromium free preservatives is increasing. Leaching of copper from wood preserved with such solutions is still higher compared to leaching from wood impregnated with copper chromium ones. In order to decrease leaching, different carboxylic acids (octanoic, 2-etilheksanoic, decanoic) were added to copper/amine/boron aqueous solutions. Experiment of leaching of copper from Norway s...
M Humar, P Kalan, F Pohleven
Leachabilty and efficacy of fatty acid derived boron esters as wood preservatives - leachability and efficacy of fatty acid derived boron esters as wood preservatives
2004 - IRG/WP 04-30351
Borates have many advantages as wood preservatives. However, boron is susceptible to depletion under humid conditions and this restricts its outdoor use. In order to reduce boron leachability in treated wood, one of the anticipative approaches is to use organic fixed boron-based preservatives. This study investigated the leachability of six boron ester compounds as potential preservatives. Scots p...
A Mohareb, J Van Acker, M Stevens
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
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
Environmentally benign wood preservatives based on organic biocide antioxidant combinations: A brief review of laboratory and field exposure results and discussion of a proposed mechanism
2004 - IRG/WP 04-30335
The combination of various organic biocides with commercial antioxidants generally increased the biocides’ efficacy 2-3 fold against wood-destroying fungi in short-term laboratory decay tests, and some positive results have been obtained after 2-4 years of outdoor exposure. The two antioxidants principally examined, propyl gallate and butylated hydroxytoluene, are low cost and, since both are f...
T Schultz, D D Nicholas, W Henry, C Pittman, D Wipf, B Goodell
Fungal detoxification of organotin biocides
1985 - IRG/WP 1258
The ability of a range of wood decaying fungi to inactivate bis(tri-n-butyltin) oxide (TnBTO) in the extracellular growth medium, in stationary liquid culture was determined. A distinction between the ability to tolerate the fungicide and to inactivate it was made: the white-rot organism Coriolus versicolor being the most efficient inactivator. In an attempt to determine the extracellular agents r...
P S Belford, D J Dickinson