Your search resulted in 240 documents. Displaying 25 entries per page.
The susceptibility of 35 Amazon wood species to Cryptotermes brevis (Walker)
1982 - IRG/WP 1160
Laboratory tests were carried to evaluate the susceptibility of 35 Amazon hardwoods to Cryptotermes brevis (Walker). The results were analysed statistically and showed that five wood species were non resistant, nine were resistant and the other twenty-one in between those classes of resistance....
M D Canedo
Natural resistance of twenty-six Guianese wood species against marine borers
1988 - IRG/WP 4144
This note is a contribution on the study of the natural resistance of some wood species from French Guiana, some of which could be found too in the neighbourhood. Here are presented the results after one year exposure in the marine environment....
L N Trong
Treatment of messmate (Eucalyptus obliqua L'Hérit) by double-diffusion: Preliminary report
1983 - IRG/WP 3234
Modified double-diffusion is suggested as a method of impregnation for mixed tropical hardwoods for certain types of ground contact use in less developed countries. Compared with vacuum/pressure impregnation, capital costs are low and little skill is needed for the operations involved. Treatment of messmate (Eucalyptus obliqua L'Herit) rounds involving pre-heating in water prior to their ...
F F K Ampong, C-W Chin
Adequate preservative treatment of tropical and subtropical hardwoods for electric anchor logs
1997 - IRG/WP 97-40101
Most available 27 different hardwood species grown in Bangladesh was investigated regarding suitability as CCA-C (chromated copper arsenate type-C) impregnated anchor logs for rural electrification programme. The kiln-drying properties, sapwood thicknesses, CCA treatability grades of sapwood and heartwood, natural durability of heartwood and CCA retainability at specific assay zone separated 27 ha...
A K Lahiry
Fungi associated with groundline soft rot decay in copper/chrome/arsenic treated heartwood utility poles of Malaysian hardwoods
1992 - IRG/WP 92-1567
Copper-chrome-arsenic treated heartwood from Malaysian hardwood utility poles in service for 8-23 y at two localities in the wet tropical Peninsula Malaysia were surveyed for soft rot in the ground-contact region. Soft rot decay was detected in all the poles. Isolation studies indicated the ability of a variety of microfungi and basidiomycetes to colonize treated heartwood. Most isolates exhibited...
A H H Wong, R B Pearce, S C Watkinson
Natural durability of eight tropical hardwoods species from Africa
2005 - IRG/WP 05-10563
Current forest inventory results reveal that there are more than 700 hundred-hardwood species in tropical forests, of which less than 10 percent are harvested and used for commercial purposes. The increased use of lesser-known species can decrease the pressure on current commercial species, increase the value of the forest and lead to better management practices. However basic information on physi...
P Nzokou, K Wehner, D P Kamdem
Identification card for Coriolopsis polyzona (Pers.) Ryv
1977 - IRG/WP 161
A Ofosu-Asiedu
The possible significance of the lignin content and lignin type on the performance of CCA-treated timber in ground contact
1988 - IRG/WP 1357
The lignin in wood samples of Alstonia scholaris, Octomeles sumatrana and a Simaruba species have been analysed. These timbers are characterised by a high lignin content and low syringyl:guaiacyl ratios. Decay tests with two soft rot fungi showed that the timbers were less susceptible than timbers with a low lignin content and higher syringyl:guaiacyl ratios. Numerous data for field performance of...
T Nilsson, J R Obst, G F Daniel
Natural decay resistance of some lesser-used tropical hardwoods from Ghana
2002 - IRG/WP 02-10438
Ghana is a tropical African country that is rich in diverse timber species. In order to reduce over-exploitation of the popular timber species and increase the resource base for the wood industry, lesser-used or lesser-known timber species are being promoted locally and for export. To do this successfully, it is essential to determine the physical, mechanical and biological properties of these tim...
S A Amartey, F R Hanson
The influence of soil pH on leaching of CCA elements from pressure-treated Eucalyptus saligna sapwood: environmental implication
2003 - IRG/WP 03-50203
Evidence is accumulating as to poor distribution and fixation of CCA in tropical hardwoods, and there is therefore a necessity to investigate the permanency of CCA in tropical hardwoods. The relationship between soil pH and leaching of Cu, Cr and As from CCA pressure-treated sapwood of Kenyan-grown Eucalyptus saligna was tested under laboratory conditions. Small sapwood samples were pressure-tre...
R Venkatasamy, D N Okwara
Marine exposure assessment of the natural resistance of a number of lesser known species of tropical hardwoods to teredinid and limnoriid borers
2004 - IRG/WP 04-10520
Naturally durable species of timber are used as an alternative to preservative treated timber for marine structures, but many species have not been evaluated for their potential for use in this environment. EN 275 specifies a 5-year test period - too long a period for screening tests to be economically viable. In this study, candidate timber species were selected for testing in the sea on the basi...
J R Williams, S M Cragg, L M S Borges, J D Icely
Comparing the resistance of a number of lesser known species of tropical hardwoods to the marine borer Limnoria using a short term laboratory assay
2003 - IRG/WP 03-10500
Naturally durable species of timber are used as an alternative to preservative treated timber for marine structures, but many species have not been evaluated for their potential for use in this environment. EN 275 specifies a 5-year test period - too long a period for screening tests to be economically viable. In this study, durability was assessed by measuring the production of faecal pellets by ...
L M S Borges, S M Cragg, J R Williams
Performance of Two Imidacloprid-Treated Malaysian Hardwoods in an Accelerated Aboveground Termite Test
2005 - IRG/WP 05-30389
The performance of the chloronicotinyl insecticide imidacloprid as a wood protecting termiticide, under a simulated Malaysian biological hazard class H2 (exposure aboveground indoors against termites and wood borers), was evaluated by a novel termite field test protocol. Replicate end-grain sealed air dried test blocks (20 x 20 x 20 mm) of two Malaysian hardwoods, Kembang Semangkok (Scaphium spp.)...
A H H Wong
Adequate preservative treatment of kiln dried Eucalyptus camaldulensis and Acacia mangium for tropical and subtropical wood poles
1996 - IRG/WP 96-40075
The Eucalyptus camaldulensis and Acacia mangium round timbers kiln-dried at EMC and full cell pressure treated with CCA-C ensured requisite penetration and adequate dry retention (30 kg/m³ or 4% w/w). The sufficient inherent strength, seasoning property, treatability of sapwood and heartwood equivalent to 44% of radius, natural durability of heartwood, and field investigation on service performan...
A K Lahiry
Termite resistance of twenty-eight Indonesian timbers
1982 - IRG/WP 1150
A comparative study of termite resistance of 28 Indonesian wood species has been conducted using small samples measuring 5 x 10 x 20 mm³. The drywood termite Cryptotermes cynocephallus (Kalotermitidae) and the subterranean termite Coptotermes curvignathus (Rhinotermitidae) were used in the study. A resistance classification was derived on the basis of cluster analysis. The result reveals that Alb...
Nana Supriana, P E Howse
Natural Durability studies and Changes in wood chemistry of some Ghanaian hardwoods during decay by white- and brown-rot fungi
2004 - IRG/WP 04-10542
The natural decay resistance of Esa (Celtis mildbraedii), Wawabima (Sterculia rhinopetela) and Dahoma (Piptadeniastrum africanum) obtained from Ghana was determined according to BS EN 113 (1997). Esa was found not durable to the white-rot, but very durable to the brown-rot; Wawabima was very durable to both white- and brown-rots; and Dahoma was durable to the white-rot, and very durable to the bro...
Zeen Huang, K Maher, S A Amartey
Tropical In-Ground Durability of Structural Sarawak Hardwoods Impregnated to High Retention with CCA-salts, CCA-oxide and FCAP after 20 Years Exposure
2005 - IRG/WP 05-30384
Statistical analysis (ANOVA) was conducted on durability (termite and decay combined) rating data collected over 20 years exposure period of over 140 species of Sarawak timbers with altogether 30,000 stake specimens, at the Forest Department’s Sibu “graveyard” stake test sites from 1977. About 20 replicated stakes were pressure-treated to refusal with 10% g/ml concentration of up to 3 CCA-sa...
Wang Choon Ling, A H H Wong
Laboratory Evaluation of Soft Rot Resistance of Non-Durable Lesser-Known Malaysian Hardwoods
2006 - IRG/WP 06-10582
Resistance of six non-durable lesser-known Malaysian hardwoods, Pulai (Alstonia spp.), Rubberwood (Hevea brasiliensis), Ludai (Sapium spp.), Jelutong (Dyera costulata), Gaham Badak (Blumeodendron tokbrai) and Kayu arang (Diospyros spp.) compared with temperate Scots pine sapwood (Pinus sylvestris), were evaluated using the unsterile soil burial (mixed with Chaetomium globosum) versus vermiculite-b...
A H H Wong
Laboratory Leaching Tests to Study the Effects of Post-Treatment Storage Periods on CCA Leachability and Fixation in Treated Permeable and Refractory Malaysian Hardwoods
2006 - IRG/WP 06-50240
The biological resistance and environmental safety of CCA-treated wood relies on the extent of post-treatment storage fixation of CCA in wood prior to being utilized. A study on the comparative leachability (fixation) of CCA-treated refractory and permeable heartwoods of 3 Malaysian hardwoods subjected to different post-treatment storage (fixation) periods of up to 4 weeks, at 2 laboratory leachin...
A H H Wong, H C Lai, N P T Lim
Marine exposure assessment in southern Portugal of the natural resistance of a number of lesser known species of tropical hardwoods to teredinid and limnoriid borers
2007 - IRG/WP 07-10614
Naturally durable species of timber are used as an alternative to preservative treated timber for marine structures, but many species have not been evaluated for their potential for use in this environment. EN 275 specifies a 5-year test period - too long a period for screening tests to be economically viable. In this study, candidate timber species were selected for testing in the sea on the basi...
J R Williams, S M Cragg, L M S Borges, J D Icely, G S Sawyer
Dimensional Stability of Nine Tropical Hardwoods from Cameroon
2009 - IRG/WP 09-10687
This study investigated the swelling behavior, rate of swelling and dimensional stability of nine tropical hardwood species from Cameroon, namely ayous (T. scleroxylon), bilinga (N. diderrichii), bubinga (G. tessmannii), iroko (C. excelsa), Makore (M. heckelii), moabi (B. toxisperma), movingui (D. benthamianus), teak (T. grandis) and zingana (M. brazzavillensis). Continuous swelling was monitored ...
S R Shukla, D P Kamdem
Natural Durability Variations of Malaysian Timbers from Sarawak after 26 Years Exposure by Stake Test
2009 - IRG/WP 09-10704
An extensive graveyard stake test site was established in 1977 in Sibu, Sarawak, Malaysia, to evaluate the in-ground durability of 132 Sarawak wood species, mainly hardwoods. Test samples were planted at 100 x 50 cm spacing. Authenticated wood specimens from 3 trees of each of 132 species were processed into 20 replicated outer heartwood (or else undifferentiated heartwood) stakes of 19 x 19 x 457...
A H H Wong, Ling Wang Choon
Fixation and leaching characteristics of Malaysian tropical hardwoods treated with CCA-C
2012 - IRG/WP 12-50289
The fixation and leaching characteristics of 8 Malaysian tropical hardwood (MTH) species treated with chromated copper arsenate (CCA-C) wood preservative were examined. The species evaluated were Acacia (Acacia mangium), Bintangor (Calophyllum sp.), Geronggang (Cratoxylon arborescens), Medang (Litsea sp.), Meranti rambai daun (Shorea acuminata), Putat (Planchonia sp.), Ramin (Gonystylus sp.) and S...
S Salim, S Shahomlail, Z Ashaari, Yong-Seok Choi, Gyu-Hyeok Kim
Classifying white rot decay resistance of some hardwoods from Sarawak and Peninsular Malaysia and correlations with their tropical in-ground durability
2012 - IRG/WP 12-10788
White rot wood decay under Malaysian (humid tropical) terrestrial conditions pose more serious threats to the in-ground service life of hardwoods than other common fungal decay types. A study is made on decay resistance variation for a total combined list of 30 Peninsular Malaysian and Sarawak timber species (plus 6 exotic reference temperate commercial woods for comparison) using the laboratory s...
A H H Wong, J M E Jem, Lai Jiew Kok
A Case Study of Long-term CCA Preservative Leaching from Treated Hardwood Poles in a Humid Tropical Condition
2016 - IRG/WP 16-50324
Chromated copper arsenate (CCA)-treated Malaysian hardwoods have long been used as utility poles, posts, construction piles and motorway fencing in soil contact exposed to the threats of decay fungi and termites. Despite global concerns citing predominantly temperate conditions of long-term leaching of CCA toxic heavy metals from wood into surrounding soils and groundwater since the 1990’s, the ...
A H H Wong, W S M Chin