Your search resulted in 7 documents.
Physical properties variation of sound and top dying affected sundriwood (Heritiera fomes) in mangrove forest of Bangladesh
2004 - IRG/WP 04-10504
Top dying of sundri (Heritiera fomes Buch.-Ham.) in the Sundarbans is considered to be the most severe of all the diseases of tree crops in Bangladesh. The wood samples from sound, moderately affected and severely affected sundri trees from three different tree heights for every individual test were collected and their respective physical properties were examined to make a comparison. It was found that density decreased with the increase of disease severity and was found 5% for both the cases. The volumetric shrinkages also increased due to top dying and were found 6.42% and 3.34% higher for moderately affected and severely affected trees respectively. Similarly the initial moisture contents also decreased due to top dying and were found 5.34% and 16.19% lower for moderately affected and severely affected trees respectively.
S C Ghosh, A K M A Bosunia, M A Islam, A K Lahiry
An environmental aspect relating to leachability of CCA from hardwood and softwood poles in Bangladesh
2001 - IRG/WP 01-50167
Leachability of CCA and the service performance of 8 softwood and 5 heartwood poles in service after 5 to 17 years in Bangladesh have been studied. The study included determination of retention of CCA-C in outer 6 mm zones at groundline (GL) and above groundline (AGL) along with the observation of decay and conditions of soils. The mean leaching of CCA-C derived from retention differential at GL and AGL are not found to be statistically significant. The existing balances of CCA-C components in poles do not indicate any leaching loss occurred. Reductions in retention have been noted at GL of softwood poles and at AGL of hardwood poles. Among several possibilities the density of wood as well as wood species/types, levels of retention, conditions of soil are found to be the prime factors which may increase leaching/depletion of CCA from the GL of softwood poles and responsible for poor performance of hardwood poles. The levels of CCA retentions in hardwood poles are not found to be adequate and equivalent to the levels of softwood poles in use. The CCA retentions of softwood poles were found still well above the toxic threshold for decay in even the oldest poles. Remedial treatments at GL of CCA-C treated hardwood poles installed in Bangladesh have been found to be essential. Very good service conditions confirm no remedial treatment necessary for CCA treated softwood poles.
A K Lahiry
Preservative requirements for exterior particleboard as predicted from accelerated laboratory evaluations
1976 - IRG/WP 265
Arguments for and against preservative treatment of exterior particleboard were considered; it was concluded that preservative treatment is desirable. Laboratory decay tests were conducted to determine levels of sodium pentachlorophenoxide required to protect exterior particleboard from decay fungi. The decay resistance of treated board was compared with that of timber (both naturally durable and preservative-treated) currently used in situations for which exterior particleboard is designed. A retention of 0.35% sodium pentachlorophenoxide per oven-dry board weight was considered to offer adequate protection to the board.
M E Hedley
Estimation of mycelial biomass by determination of the ergosterol content of wood decayed by Coniophora puteana and Fomes fomentarius
1989 - IRG/WP 1415
The mycelial biomass of fungi decomposing wood materials may be estimated by the use of an ergosterol assay technique.ln decay tests, essentially according to EN 113, estimates made by HPLC analyses on wood decayed by Coniophora puteana and Fomes fomentarius show the increase in biomass in the wood blocks. The ergosterol contents were correlated with dry weight loss determinations. Degradation of wood in relation to colonization is discussed.
K Nilsson, J Bjurman
Evaluation of bending strength by non-destructive methods of Ezomatzu with white pocket rot
1991 - IRG/WP 2371
The possibility of application of three non-destructive methods was examined for evaluation of bending strength of ezomatsu (Picea jezoensis CARR.) with white pocket rot. As non-destructive methods, the measurements of ultrasonic wave propagation time, impact-induced stress wave propagation time and penetration depth of pin of "PILODYN Wood Tester" were applied to compare with visual evaluation of degree of white pocket rot. The modulus of elasticy in bending, bending strength and stress at proportional limit in bending were decreased according as increase of the degree of white pocket rot evaluated visually, even at "slight and superficial" rot. High correlations were observed between dynamic modulus of elasticity calculated through ultrasonic wave propagation time or stress wave propagation time and modulus of elasticity in bending, and between dynamic modulus of elasticity and bending strength. The penetration depth of pin and modulus of elasticity in bending or bending strength were correlated as well. Based on the results obtained by this experiment, these three non-destructive methods were serviceable to evaluate modulus of elasticity in bending and bending strength of ezomatsu with white pocket rot, same as visual evaluation.
Research studies on infecting behaviour of Fomes fomentarius (L. ex FR) Fr. and its physical control in the wood yards of the Hyrcanian (Caspian) forests of Ira
1996 - IRG/WP 96-10179
Due to illegal cutting, girdling and ringbarking many damages of tinder fungus (Fomes fomentarius (L. ex Fr) Fr.) are seen on beech, poplar, oak and birch at Hyrcanian (Caspian) forests of Iran. The beeches (Fagus orientalis Lipsky) are damaged highly and the beech community of Fagetum are infected from 800 meter altitudes at Gorgan (East of Caspian forests) to 600 meters altitudes at Gilan (West of Caspian Forests belt of Iran) and totally the damage is seen up to a height of 2000 meters.
A study of fungal biodeterioration in unseasoned, packaged hem-fir lumber
1978 - IRG/WP 2116
This study was undertaken to determine the extent of biodeterioration that could occur within British Columbia (BC) prior to the export of packaged Canadian Lumber Standard Hem-Fir (Tsuga heterophylla, Abies amabilis and small amounts of Abies grandis). By examining the anti-stain treatments received by the lumber and identifying and characterizing the organisms responsible for the biodeterioration, recommendations can be made to the industry for improved quality control. The majority of unseasoned, packaged Hem-Fir lumber awaiting export from BC is less than 5 months old. During this period of transit and storage, fungal biodeterioration is observed to be slight, in spite of low anti-stain chemical retentions indicated by analysis. However, after eight months in transit, packages show a significantly greater percentage of heavily stained pieces and increased spread of infection by wood-destroying fungi. Of the fungi responsible for the observed biodeterioration, Graphium was found to be the most common staining organism and Fomes pinicola the most abundant wood-destroying fungus. Decay studies of hemlock sapwood showed that Fomes pinicola poses a serious threat to packaged Hem-Fir lumber, with the potential ability to cause rapid and widespread decay. Based on these findings, and the previous work of Roff, Cserjesi and Swann (1974), recommendations are being made to BC lumber manufacturers for improving their anti-stain treating methods. Increased chemical retention on the lumber can be obtained by dipping individual pieces of lumber or otherwise thoroughly drenching with anti-stain solution instead of using the spray systems currently in use. In addition, increasing the concentration of the anti-sapstain solution will result in a surface retention of chemical capable of preventing attack by moulds and staining and wood-destroying fungi. Implementation of these recommendations will result in improved quality of Hem-Fir lumber for the export market and in the long term contribute to the conservation of Canada's lumber resources
P W Perrin, A J Cserjesi