Your search resulted in 228 documents. Displaying 25 entries per page.
Evaluation of New Zealand staining fungi for degradation of radiata pine
1999 - IRG/WP 99-10310
This investigation sought to determine the potential of selected NZ staining fungi to induce weight loss and changes in toughness (impact bending strength) and composition in unseasoned radiata pine sapwood. Furthermore, assays were performed to eveluate enzyme production by staining fungi. Sets of side-matched specimens were inoculated with Ophiostoma floccosum, Sphaeropsis sapinea and O. plurian...
A Schirp, R L Farrell, B Kreber
Comparison of decay rates of preservative-treated stakes in field and fungus cellar tests. Results after 40 months fungal cellar exposure
1983 - IRG/WP 2200
Decay rates of preservative-treated Pinus radiata stakes during 40 months exposure in the FRI fungus cellar were compared with those of similarly treated material in a field test. Decay rates in the fungus cellar were from 4 to 100 times higher than in the field, although for the majority of preservatives the rate was between 7 and 12 times higher. The lag phase before onset of decay, noticeable w...
M E Hedley
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
The performance of CCA treatment in bamboo against decay fungi
1993 - IRG/WP 93-30027
Samples of culm wall material from young (< 6 month age) and mature (> 3 years age) culms of the bamboo, Phyllostachys virideglaucescens were treated to equivalent% w/w retentions of a CCA preservative. After fixation and leaching the treated samples were exposed to decay by Chaetomium globosum FPRL S70K, Coriolus versicolor FPRL 28A and Coniophora puteana FPRL 11E. Thin section samples of u...
O Sulaiman, R J Murphy
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
Effectiveness of Busan 30 treated birch blocks in a soil medium
1987 - IRG/WP 3409
TCMTB based formulation has been anticipated for use in dip-diffusion treatment in Papua New Guinea to replace BFCA Wood preservative. One such formulation is the Penacide (TCMTB + MBT Boron) which is currently being tested against fungi and insects. Accelerated laboratory test in soil exposure was employed to test a related formulation (Busan 30) to determine its effectiveness against soil inhabi...
H C Konabe
Sludge formation in timber treatment with CCA preservatives. Origin and elimination
1984 - IRG/WP 3276
The exact distributions between lignin and holocellulose and retentions on wood of copper, chromium and arsenic as a function of various sets of conditions in a factorial experiment in which combinations of three temperatures of treatment, three CCA solution concentrations, four pH's of the initial CCA solution and two timber species, namely Pinus radiata and Eucalyptus grandis, are repor...
A Pizzi, W E Conradie, A Jansen
Kinetic of the wood degradation produced by wood decay fung
1993 - IRG/WP 93-20016
The degradation degree of a wooden structure has a direct influence on its loss of mechanical strength. It's necessary to deepen in non destructive techniques which permit to extrapolate the results obtained in laboratory to structural timber used in the building's construction. This work studies the relationship existing between the pulse velocity of ultrasonic waves and the wei...
M T De Troya, A M Navarrete, A Sanchez, V Bucur
High CCA retentions and the protection of eucalypt power poles
1983 - IRG/WP 3226
Tasmanian power pole material treated to high retentions, was analysed to accurately determine the amount of CCA preservative in the timber. Material from the same disc was subsequently exposed in unsterile soil in order to determine the effectiveness of treatment. Results showed that even at high retention levels, soft-rot attack was not prevented. Fourteen further poles were sampled, but this ti...
L E Leightley, J Norton
The effect of ACC (Celcure) on durability of blue beech
1999 - IRG/WP 99-30209
Durability of the sapwood and heartwood of blue beech (Carpinus betulus) against white rot fungus (Coriolus versicolor) was studied. As treatment three concentrations of preservative (control or 0%, 3%, and 5% of ACC) were applied. The measuring 1.5x2.5x5cm3 as dimension of wood samples (sap and heartwood) was used. During 16 weeks exposure, untreated wood blocks were completely deteriorated by th...
S M Kazemi
Decay Resistance and Bonding Properties of Structural Flakeboard
2002 - IRG/WP 02-40233
Experimental structural flakeboard panels consisting of differing furnishes and resins were produced and tested for internal bond, linear expansion, thickness swell, and decay resistance. One group of panels was produced with recycled CCA-treated wood as the furnish and commercial phenol formaldehyde (PF) resin as the binder. Other groups of panels were produced with either mixed hardwoods or so...
T F Shupe, Chung-Yun Hse
Decrease of the antidecay resistance of beech wood treated with organotin fungicides after its natural ageing
1998 - IRG/WP 98-30185
The antidecay resistance of beech-wood samples (120 x 8.5 x 8.5 (MM)) treated with tributyltin fungicides gradually decreased due to prolongation of their natural ageing:
tributyltin fungicides (TBTO, TBTS, TBTCA, TBT-DEDTK were applied by pressure impregnation technique in ethanole solutions (c = 0. 1%, 0.33% or 1%);
treated beech-wood samples were naturally aged without their contact with grou...
L Reinprecht
EELS (Electron Energy Loss Spectroscopy) - a technique for quantification of nitrogen and other light elements in the cell wall
1999 - IRG/WP 99-20163
A literature survey was performed to find progress in techniques for monitoring penetration of synthetic resins in wood cell walls. Electron energy loss spectroscopy (EELS) in combination with transmission electron microscopy (TEM) was successfully applied for the high resolution examination of the distribution of a partly methylated hydroxymethyl melamine resin in Norway spruce (Picea abies Karst...
A O Rapp, H Bestgen, W Adam, R-D Peek
Wood decay of Pinus sylvestris L. by marine fungi
1990 - IRG/WP 1463
Waterlogged wood decay by marine microorganisms represents a major problem for the conservation of wood structures of historic value. It is important to know which kind of decay affects the wood from a conservation point of view. Enzyme activities of 14 marine fungi belonging to several localities were studied. Also, the weight loss and the rot type suffered by the wood at a microscopic level were...
M C Escorial, M T De Troya, J E Garcia de los Rios
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
Microscopical analysis of formaldehyde-acid modified wood
1981 - IRG/WP 3182
Cross-linking of wood with gaseous formaldehyde improves its hygroscopic and dimensional behaviour, and its resistance against micro-organisms. However, formaldehyde cross-linking reactions take place only in the presence of an acid catalyst, which results in losses in mechanical By optimization of a formaldehyde-sulfur dioxide vapour phase process the reaction conditions were established to limit...
M Stevens, N Parameswaran
Investigation on different variation factors in the results of mycological test and means to reduce and avoid them
1986 - IRG/WP 2264
In order to clarify the causes of the dispersion observed in the results obtained with mycological tests made in accordance with standard EN-113, different factors assumed to be sources of the variations were studied. These included the moisture content of the test samples during the test, the influence of certain technological properties of the wood, the virulence of the fungus strains, the metho...
D Dirol
Decay and mold resistance of borate modified oriented strandboard
2003 - IRG/WP 03-40260
Decay and mold resistance of zinc borate (ZB) and calcium borate (CB) modified
oriented strandboard (OSB) from southern mixed hardwoods and yellow pine was investigated in this study. Tests were done with brown rot, Gloeophyllum trabeum, and white-rot, Trametes versicolar, fungi for 8 and 12 weeks, respectively. Wood species and fungus type had significant influence on the decay resistance. Decay...
Q Wu, S Lee, J P Jones
The use of modulus of rupture and modulus of elasticity in natural durability testing
1997 - IRG/WP 97-20117
Losses in weight, losses in bending strength and changes in elastic behaviour were assessed in a fungus cellar test with beech wood stakes (Fagus sylvatica). Results were gained after 8, 12, 16 and 20 weeks resp . The outcomes show, that the non-durable species beech is very rapidly attacked by fungi and loses up to 60% of its initial bending strength even within the first 8 weeks. Earlier researc...
L Machek, H Militz, W Gard
Improvement of wood decay resistance by tannin impregnation
1991 - IRG/WP 2380
The fungical effect of tannins is appraised after exposure of treated woods samples to wood rotting fungi. A screening-test is carried out with several solutions containing extracts of two kinds of tannins; a condensed tannin derived from Quebracho heartwood (Schinopsis sp.) and a hydrolyzable one extracted from chestnut heartwood (Castanea sativa Mill). If a fungicidal action was indeed found it ...
D Dirol, A Scalbert
Effects of surfactants and ultrasonic energy on the treatment of wood with chromated copper arsenate
1977 - IRG/WP 3108
Sugar pine stakes 1'' x 1" x 16" were treated by a hot-water bath followed by soaking in cold CCA solution for 10 to 30 minutes. A similar number of stakes were treated by a cold-cold bath. Half of the stakes were subjected to ultrasonic energy during the CCA bath. The mean absorption for stakes given the hot-cold bath was 18.52 pcf (297 kg/m³) and 4.64 pcf (74 kg/m³) for those...
C S Walters
Accelerated decay tests to investigate postulated effects of tannins on CCA efficacy in wood
1988 - IRG/WP 3497
Five groups of blocks (10 x 10 x 5 mm³) viz., Pinus patula, Pinus patula impregnated to 4% (w/w) tannin; Eucalyptus grandis, Eucalyptus grandis with natural tannins extracted; and extracted Eucalyptus grandis with tannins returned as above; were prepared. Blocks from each group were then treated to 0, 5, 10 and 15 kg/m³ CCA and challenged in four 15-week decay tests, viz., soil burial, and expos...
U L Scherer, A A W Baecker
Chemical evaluation of borate treated pine sapwood attacked by the subterranean termite Coptotermes acinaciformis
1993 - IRG/WP 93-20003
Sapwood of hoop (Araucaria cunninghamii Ait. ex D. Don) and slash (Pinus elliottii Englem.) pines were treated by Vacuum Pressure Impregnation (VPI) to provide test specimens. The concentration of boron was defined by chemical analyses of the timber, in the zone of primary attack by the termite being bioassayed. A common method of definition of preservative retention, weight uptake of preservative...
A R Moffat, B C Peters
The critical moisture and temperature conditions for the growth of some mould fungi and the brown rot fungus Coniophora puteana on wood
1988 - IRG/WP 1369
The growth of some mould fungi on pine and spruce sapwood was studied in 40 different constant moisture and temperature conditions. The temperature range was between +10 and +40°C and the relative humidities varied from 76 to 100% relative humidity (RH). The incubation time was 12 weeks. The mixed mould inoculation used included typical fungi growing on wood: Aspergillus versicolor, Cladosporium ...
H Viitanen, L Paajanen
Hygroscopicity of decayed wood - Implications for weight loss determinations
1996 - IRG/WP 96-20085
Hygroscopicity changes were observed in red maple blocks subjected to brown rot, white rot and soft rot. Brown rot reduced hygroscopicity, soft rot increased hygroscopicity, and white rot showed only a very slight increase in hygroscopicity. The effect of these changes on weight loss tests is a slight overestimation of weight loss for brown rot and a slight underestimation for soft rot and white r...
S E Anagnost, W B Smith