Your search resulted in 211 documents. Displaying 25 entries per page.
Programme Section 1, Biology
1998 - IRG/WP 98-10293
IRG Secretariat
Newsletter 2-98
1998 -
IRG Secretariat
Time dependent over-uptake of etherificated melamine resins
1998 - IRG/WP 98-40109
Waterbased methanol-etherificated melamine-formaldehyde resins can increase the fungal resistance of the treated wood though they are known to be non-toxic. Therefore melamine-resins are at the present an object of research activities of European projects and of some companies. The paper highlights the importance of quoting the duration of the diffusion when immersed in the treating solution, as m...
D Lukowsky, R-D Peek
How best to specify retentions of preservative treatments: kg/m3 or % (m/m)
1998 - IRG/WP 98-20151
When specifying treatments according to the European Standard EN 351-1, retentions in the analytical zone are based on the amount of product found to be effective in biological tests; this is expressed in terms of the retention of the product per unit volume (kg/m3) for penetrating treatments and per unit area (g/m2) for superficial treatments. However, to check whether the retentions have been ac...
J K Carey
Borates and their biological applications
1998 - IRG/WP 98-30178
This paper reviews some of the many biological applications of borates. Boron is a ubiquitous element found widely distributed in the environment and is a normal component of a healthy diet. Elemental boron does not exist in nature, but is always found combined with oxygen in compounds called borates. Boron is an essential micronutrient for plants, and there is evidence to suggest that boron is of...
J D Lloyd
Antifungal mechanism of dichloro-N-octylisothiazolone
1998 - IRG/WP 98-30183
4,5-dichloro-N-octylisothiazolin-3-one (DCOI) is a member of the isothiazolone class of preservatives, whose antimicrobial mechanism of action has been intensively studied over the last decade. DCOI has also been intensively studied for use in wood preservation. The isothiazolones are electrophilic molecules that rapidly react with thiol groups to form covalently bonded isothiazolone-thiol adducts. This ability to bond with thiol groups is crucial to their ability to act as preservatives.
Thiol groups are present in proteins as part of the amino acid cysteine, where they play an important role in maintaining protein structure and function. A number of enzymes have thiol groups at the site where the enzyme function is performed, and these thiol groups may participate in the enzyme reaction. If the isothiazolone reacts with this thiol group, the activity of the enzyme is inhibited. Our studies have shown that there are several enzymes in the Krebs cycle that are inhibited by isothiazolones and these enzymes are required to generate energy and perform many biosynthetic functions. Reflective of this, DCOI has been shown to be a rapid inhibitor of cellular respiration, causing the cell to cease consuming oxygen almost immediately upon contact with DCOI. The multiplicity of targets and their central importance to the metabolism of the cell, as well as the fact that all microbes use at least parts of the Krebs cycle, can be related to the low use levels and broad spectrum of activity of DCOI.
The antimicrobial mechanism of DCOI results in a potent rapid-acting preservative with a broad spectrum of antifungal and antibacterial activity that is effective at low levels.
J S Chapman, M A Diehl, K B Fearnside, L E Leightley
An appraisal of methods for environmental testing of leachates from salt-treated wood (2)
1998 - IRG/WP 98-50110
For wood preservatives for use in hazard class 4 information on the ecotoxicity of preservatives and ingredients as well as on the effect of losses from impregnated timber is needed for a proper environmental risk assessment.
In the evaluation of a suitable test procedure the leaching behaviour of copper-based formulations was studied using analytical and ecotoxicological test methodology. These ...
H W Wegen, A Platen, G M F Van Eetvelde, M Stevens
Evaluation of the leach resistance and preservative efficacy of novel biocides as surface treatments applied by brush to spruce (Picea abies)
1998 - IRG/WP 98-30170
The comparative leach resistance and preservative efficacy of a number of alternative organic preservatives (available from Zeneca Specialties) and selected commercially available biocides as surface coatings to wood in Hazard Class 3 have been assessed. Two concentrations of test preservatives were applied by brush to Spruce (Picea abies), including formulation and untreated controls. A leaching ...
I M Tierney, A Bruce, D C R Sinclair, T Yeates
Protection of Ochroma pyramidale from fungal decay with N,N-napthaloylhyroxylamine
1998 - IRG/WP 98-30182
Fungal decay of wood in service results in billions of dollars (U.S.) in losses annually. Recent environmental restrictions, both U.S. and international, are limiting and eliminating the use of broad-spectrum, heavy metal biocides for wood preservation. Restrictions result primarily from problems with disposal. New wood preservatives need to be developed and tested which specifically target key el...
F Green III, T L Highley
CCA component distribution in the heartwood of treated lodgepole pine and white spruce
1998 - IRG/WP 98-30173
As part of a comprehensive study on the influence of drying on heartwood permeability, the distribution of copper, chromium and arsenic (CCA) in lodgepole pine (Pinus contorta Dougl.) and white spruce (Picea glauca (Moench) Voss.) heartwood was examined with light microscopy. Stained microtomed sections were examined to determine the penetration pathway for the CCA. The microscopic observations re...
Y An, J N R Ruddick, P I Morris
Environmental risk assessment of preservative treated wood
1998 - IRG/WP 98-50101-19
This paper reviews the status of the environmental risk assessment of preservative treated wood and confirms the distinction between the risks presented by wood preservatives and preservative treated wood. The paper proposes a tiered approach to risk assessment and discusses the rationale. Flowcharts are presented which summarise the tiered approach to risk assessment, show the tests required, and...
E F Baines, S J Davis
How to determine what is a realistic emission from treated wood - basic reflections
1998 - IRG/WP 98-50105
Emissions from treated wood occur by evaporation and by leaching. Up to date by far more experience exists on leaching tests than on evaporation test. The methods applied will be of interest to give answers to the questions about the quantity of possible emissions. Standardisation on leaching started very early. One of the first attempts to quantify the effect of leaching on the remaining efficacy...
H Willeitner, R-D Peek
Patterns of long-term performance - How well are they predicted from accelerated tests and should evaluations consider parameters other than averages?
1998 - IRG/WP 98-20130
This paper is a discussion of whether different service-life distribution patterns of products treated with unlike preservatives can be predicted, modeled, characterized, or even anticipated from accelerated laboratory tests. Graphic displays of data from Forest Products Laboratory field plots with preservative-treated and fire-retardant-treated stakes demonstrate the importance of local environme...
R C De Groot, J W Evans
Decay resistance of high performance biocomposites based on chemically modified fibres
1998 - IRG/WP 98-40120
Different partners within the framework of a European research project produced high performance biocomposites aiming at the utilisation of board materials as durable products both in dimensional and biological degrading circumstances. This paper summarises test data, which indicate the potential of board materials produced with modified fibre material. The chemical modifications applied cover a r...
V Rijckaert, J Van Acker, M Stevens
Degradation of the normal fibre walls of rubberwood (Hevea brasiliensis) by the tropical blue-stain fungus Botryodiplodia theobromae
1998 - IRG/WP 98-10286
Rubberwood was examined by light microscopy and transmission electron microscopy (TEM) after exposure to the common tropical sapstain fungus Botryodiplodia theobromae for four weeks to study hyphal colonisation of wood cells and to determine if this fungus also degraded lignified normal fibre cell walls in addition to the walls of non-lignified elements. Light microscopy revealed relatively large ...
A A H Wong, A P Singh
Environmental behaviour of treated wood in (semi-)permanent contact with fresh or seawater
1998 - IRG/WP 98-50101-20
This study presents a strategy for the environmental toxicity evaluation of treated wood towards the aquatic compartment, using non target water organisms toxicity tests. A lixiviation process is applied on wood (Pinus sylvestris) treated with several wood preservatives formulations. The lixiviation process is carried out in the laboratory with ultrapure water or synthetic seawater.
After chemica...
P Marchal, C Martin
Criteria for basidiomycetes testing and ways of defining natural durability classes
1998 - IRG/WP 98-20144
Within the framework of a European research project several laboratories have tested a series of 17 wood species covering the total range of natural durability.
Basidiomycete tests are part of the total set up. Although generally based upon standard methods some minor differences in execution of the tests were evaluated for their impact on the results. This variation was superimposed with the fac...
J Van Acker, M Stevens, J K Carey, R Sierra-Alvarez, H Militz, I Le Bayon, G Kleist, R-D Peek
Fungal resistance of smoke-dried Cryptomeria japonica wood
1998 - IRG/WP 98-40118
Performance of smoke dried wood on fungal resistance was studied. The maximum temperature of the smoke seasoning was 80-90°C in the drying room and 70-80°C within the wood for 6 days during the treatment for 15 days. Decay resistance of smoke-dried Cryptomeria japonica wood was evaluated using a brown rot fungus, Tyromyces palustris. Weight losses of untreated wood, smoke-dried wood, and smoke-d...
K Yamamoto, I Momohara, T Nishimura
Influence of a dipping preservative treatment on the performance of wood finished with waterborne coatings
1998 - IRG/WP 98-40121
Within a larger European research project on the performance of joinery finished with waterborne coatings, the influence of a water based dipping preservative treatment was studied in several ways. Six different waterborne coatings were tested with and without a preservative underneath the coating. The performance was tested on pine sapwood and spruce panels in a 2-year outdoor weathering trial on...
M De Meijer, J Creemers, W Cobben, P Ahola
Alternative technologies for wood wastes recycling - Part B: Biotreatment of PCP- and creosote-treated wood
1998 - IRG/WP 98-50101-18 b
Alternative technologies have been investigated to detoxify treated wood. Two classes of organic compounds are studied. Creosote-treated wood are classified in France as dangerous wood wastes. A conventional incineration could be provided for these wood wastes but the cost of this elimination could be very high (> 2000 FFR/ton). For these reasons, we have tested two kinds of new processes as al...
S Legay, P Marchal, G Labat
The use of immunofluorescence labelling for detecting Ophiostoma piceae in radiata pine
1998 - IRG/WP 98-10268
The primary objective of the current investigation is to understand fungal interactions of dominant sapstaining fungi in radiata pine using confocal laser scanning microscopy (CLSM).
In the current paper, an immunofluorescence labelling technique was developed for detection of Ophiostoma piceae using a monoclonal antibody. The primary antibody was labelled with Oregon green 514 Goat anti-mouse Ig...
Ying Xiao, B Kreber, C Breuil
Blue stain resistance of exterior wood coatings as a function of their typology
1998 - IRG/WP 98-20145
Paints and wood stains were evaluated on their blue stain resistance using both EN 152 method and the reverse method. The typology of these exterior coatings was varied including standard and high solid solvent-borne coatings as well as different types of waterborne coatings. For the water-borne acrylic, alkyd based and hybrid coatings both applied as opaque primer paints and as decorative wood st...
J Van Acker, M Stevens, C Brauwers, V Rijckaert, E Mol
Bioassays for rapid assessment of heavy metal toxicity in seawater
1998 - IRG/WP 98-50112
In evaluating the effect of CCA leachate on the establishment of fouling communities on wood exposed in the sea, three organisms were assessed as biological indicators of heavy metal toxicity. These were two macroalgae, Fucus serratus and Undaria pinnatifida. and the motile protist thraustochytrid, Schizochytrium aggregatum. The choice of these organisms for the tests carried out was based on the ...
C J Brown, R L Fletcher, R A Eaton
The effect of felling time of year on CCA fixation rate and quality of selected hardwoods
1998 - IRG/WP 98-40116
White birch (Betula papyrifera), poplar (Populus sp.) and red maple (Acer rubrum) trees were harvested in winter, in spring, before the leaves flushed, after leaf flush and later in the summer. Sapwood discs were cut from the freshly felled trees, dried and cut into 25 mm and 19 mm cubes. The cubes were pressure impregnated with CCA-C and fixed under high relative humidity and at 50°C or at room ...
Y T Ung, A Taylor, P A Cooper, D P Kamdem
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