Your search resulted in 219 documents. Displaying 25 entries per page.
Utilization of thermodesorption coupled to GC-MS to study kinetics of thermodegradation of different wood species
2011 - IRG/WP 11-40559
Thermdesorption coupled to Gas Chromatography coupled to Mass Spectroscopy (TD-GC-MS) has been investigated to identify volatile degradation products generated during wood heat treatment by mild pyrolysis. For this purpose, wood samples of different softwood and hardwood species have been heat treated under nitrogen for different temperatures comprised between 180 and 230°C during 15 min. in the ...
K Candelier, M Chaouch, S Dumarçay, A Pétrissans, M Pétrissans, P Gérardin
Utilization of thermodesorption coupled to GC-MS to characterize volatiles formation kinetics during wood thermodegradation
2012 - IRG/WP 12-40587
Identification of volatile degradation products produced during wood mild pyrolysis is important to have better insight on thermodegradation mechanisms. Previous studies have shown that thermodesorption coupled to GC-MS is an attractive tool to characterize and quantify products formed during wood thermodegradation indicating an higher susceptibility of hardwoods to thermodegradation compare to so...
K Candelier, S Dumarçay, A Pétrissans, M Pétrissans, P Kamdem, P Gérardin
Weather degradation of thin wood samples
2016 - IRG/WP 16-20578
Untreated wooden surfaces degrade when exposed to varying doses of natural weathering. In this study, thin wood samples were studied for weathering effects with the aim of modeling the degradation utilizing Near-infrared hyperspectral imaging. Several sets of samples were exposed outdoors for time intervals from 0 to 21 days, and one set of samples was exposed to UV-radiation in a laboratory chamb...
I Burud, K A Smeland, K Hovde Liland, T K Thiis, J Sandak, A Sandak, L Ross Gobakken
Microbiological degradation of wooden piles in building foundations
1988 - IRG/WP 1370
White rot, soft rot and bacterial attack have been detected in softwood piles under buildings. In some cases bacteria were found to be the main degradation organisms in the studied piles. The water content of degraded piles was very high. The compression strength was quite low also in the piles deteriorated by bacteria. The density of wood was very variable, and the degree of degradation could not...
L Paajanen, H Viitanen
Fungal and bacterial attack of CCA-treated Pinus radiata timbers from a water-cooling tower
1991 - IRG/WP 1488
Transmission electron microscopy of decaying CCA-treated Pinus radiata timbers from an industrial water cooling tower showed presence of a thick biofilm covering some areas of the wood. The biofilm contained various morphologically distinct forms of microorganisms embedded in a slime. The study provided evidence of the activity of soft rot fungi and tunnelling and erosion bacteria in wood cells. T...
A P Singh, M E Hedley, D R Page, C S Han, K Atisongkroh
Ultra-structural observations on the degradation of wood surfaces during weathering
1987 - IRG/WP 2280
Radiata pine (Pinus radiata D. Don) sapwood was converted into blocks with a transverse face about 5 mm square and measuring 8 mm longitudinally. Transverse (T.S.), Radial (R.L.S.) and Tangential (T.L.S.) surfaces were prepared and specimens exposed to the weather inclined at 45° facing equatorially for periods of between 20-60 days. After 30 days exposure erosion of the middle lamella was observ...
P D Evans, S Thein
Resistance of Alstonia scholaris vestures to degradation by tunnelling bacteria
1992 - IRG/WP 92-1547
Electron microscopic examination of vessels and fibre-tracheids in the wood of Alstonia scholaris exposed to tunnelling bacteria (TB) in a liquid culture showed degradation of all areas of the secondary wall. The highly lignified middle lamella was also degraded in advanced stages of TB attack. However, vestured pit membranes and vestures appeared to be resistant to degradation by TB even when oth...
A P Singh, T Nilsson, G F Daniel
Effect of medium-term degradation of beech wood by erosive (Phanerochaete chrysosporium) and lignin-selective (Ceriporiopsis subvermispora) strains of white rot fungi on its selected physical properties
2004 - IRG/WP 04-40292
At the Faculty of Wood Sciences and Technology a fungal delignification of normal and tension beech wood by erosive and lignin-selective strains white-rot fungi has been studied. The pre-treatment of both kind of wood samples was accompanied by partial delignification and apparent changes of their physical properties influencing the polar liquids penetration....
R Solár, S Kurjatko, M Mamonová, J Hudec
Soft rot cavity widening - A consideration of the kinetics
1984 - IRG/WP 1227
Studies on the micromorphology of soft rot cavity formation by Phialophora hoffmannii in birch using time-lapse cinemicrography are briefly outlined. A mathematical model is constructed to describe the cavity widening process, particularly changes in the surface area of a hypothetical cavity during enlargement. On comparison with observed data it is concluded that the rate of cavity widening is de...
M D C Hale, R A Eaton
A discussion of current theories concerning CCA fixation
1983 - IRG/WP 3238
The understanding of the fixation mechanism of CCA and related preservatives in wood has been greatly improved by a significant series of recent scientific papers. In view of recent concerns in New Zealand regarding the long-term efficacy of CCA in high decay-hazard situations, it was considered appropriate to review this recent work and to contrast it with theories presented by previous workers....
D V Plackett
Detoxification of preservatives: Tri-n-butyltin oxide as a biocide
1982 - IRG/WP 1156
T E Dudley-Brendell, D J Dickinson
The present classification of wood degradation factors
1994 - IRG/WP 94-10071
The revised version of classification of wood degradation factors is presented after discussion and remarks sended by IRG-Members. The classification contains the biotic and abiotic factors in two aspects: etiological and symptomatical....
Studies of the distribution and degradation of tributyltin naphthenate in double-vacuum treated wood
1983 - IRG/WP 3230
The effects of forced solvent evaporation by kilning redwood (Pinus sylvestris) that has been double-vacuum treated with tributyltin naphthenate (TBTN) have been investigated. Contrary to previous studies reported, it has been shown that forced evaporation can have a considerable influence on the losses of the fungicide. It has been found that, whether the solvent is allowed to evaporate slowly or...
J Jermer, M-L Edlund, W Hintze, S V Ohlsson
Accelerated ageing of preservatives in treated wood
1988 - IRG/WP 3476
New preservatives are tested in the laboratory and often in field tests before they are used commercially. Some preservatives, however, tested in the laboratory do not show the expected stability when used in service. The differences between laboratory tests and practical use can never be completely eliminated but must be minimized as far as possible by relevant testing methods. Studies of the eff...
M-L Edlund, B Henningsson, B Jensen, C-E Sundman
Contribution to study of the degradation caused in Pinus spp. poles used in field test
1989 - IRG/WP 1417
The study of the degradation produced by soil natural microflora on wood in contact with it in the field, has been going on for several years now. Our contribution to this aim in the present work has dealt with the possible relationship of the microorganisms in the soil. The microscopic visualization of wood colonization by the microorganisms, and the chemical analysis of the degraded wood compare...
M T De Troya, A Garcia, M J Pozuelo, A M Navarrete, A Cabanas
Cytochemical localization of hydrogen peroxide in brown rot fungus Tyromyces palustris by cerium chloride technique
1999 - IRG/WP 99-10299
Cerium chloride (CeCl3) was used to localize H2O2 cytochemically for studying relationship between ultrastructural and functional characteristics of cellulose degradation by brown rot fungi. This technique proved very useful in localizing discrete electron-densereactionproducts at high resolution with minimal nonspecific deposition. The cytochemical localization of extracellular H2O2 by CeCl3 usin...
Yoon Soo Kim, Seung-Gon Wi
Ultrastructural and TEM-EDAX studies on the degradation of CCA treated radiata pine by tunnelling bacteria
1985 - IRG/WP 1260
An ultrastructural study was carried out on bacterial attacked Pinus radiata stakes treated with a high level (24.7 kg/m³) of Tanalith NCA preservative. The purpose of the investigation was to determine whether the organism possessed intracellular and/or extracellular detoxification mechanisms in order to overcome the high levels of copper, chrome and arsenic present within the wood fibre walls. ...
G F Daniel, T Nilsson
Airborne algae as a wood degradation factor
1992 - IRG/WP 92-1549
The occurrence of airborne (aerophytic) algae on wood is a very frequent phenomenon. However, there is currently a lack of information concerning their effect on the wood tissue. Some important genus of algae infesting wood under natural conditions are listed, as well as the results of experimental studies in the "in vitro" culture concerning the effect of two selected algal species on some physic...
K J Krajewski, J Wazny
Biological agents of timber degradation in Portugal. Marine borers
1991 - IRG/WP 4171
A brief report of the studies carried out in Portugal on marine borers is presented. The marine borers found in the portuguese coast are refered as well as the wood species where those organisms were identified. Emphasis is given to a study carried out from 1960 to 1975 at the Tagus estuary in Lisbon with the purpose, among others, of establishing the natural durability of different timbers....
J S Machado, L Nunes
Ultrastructure of the attack of a naturally durable timber by tunnelling bacteria
1990 - IRG/WP 1462
The attack of the wood of Eusideroxylon zwageri, a naturally durable species, by tunnelling bacteria (TB) was examined by light microscopy and transmission electron microscopy. Observations were made primarily on fibres. Parenchyma were included in some cases. Both fibres and parenchyma are rich in extractives. In fibres, extractives are primarily present in the lumen. The amber colouration of fib...
A P Singh, T Nilsson, G F Daniel
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
Synergistic effects between 2-HPNO, Irganox 1076 and EDTA on the inhibition of wood degradation by Coriolus versicolor
2004 - IRG/WP 04-30331
The efficiency of 2-hydroxypyridine-N-oxide (2-HPNO) as wood preservative has been investigated. As shown using classical experiments as well as using response surface methodology, the efficiency of 2-HPNO as wood preservative is strongly improved in presence a chelator like EDTA and/or of Irganox 1076 an industrial antioxidant. In these conditions, wood preservative efficiency of the mixture the ...
A Mabicka, S Dumarçay, N Rouhier, M Linder, J P Jacquot, P Gérardin, E Gelhaye
The effects of heat treament on the specific gravity of beech and spruce wood
2003 - IRG/WP 03-40254
The effects of heat treatment on specific gravity of beech (Fagus orientalis) and spruce wood (Picea orientalis) naturally grown and intensively used in forest products industry in Turkey were studied. The wood samples were cut into 2 x 2 x 3 cm. Heat treatment was than applied to the wood samples at four different temperatures (130 °C, 150 °C, 180 °C and 200 °C) and three different durations...
S Yildiz, Ü C Yildiz, G Colakoglu, E D Gezer, A Temiz
A comparison of the effectiveness of a vacuum oven and a wind tunnel in the accelerated ageing of treated wood by evaporation
1989 - IRG/WP 2334
R J Orsler, G E Holland
The effect of didecyldimethylammonium chloride on growth of different strains of mould fungus Gliocladium roseum
1995 - IRG/WP 95-10105
The tolerance and degrading ability of different strains of Gliocladium roseum towards didecyldimethylammonium chloride (DDAC) were studied. All four of the strains of Gliocladium roseum were tolerant to DDAC and after their growth on amended malt agar, the retention of DDAC in the medium was reduced....
Yu Zheng, J N R Ruddick