Your search resulted in 919 documents. Displaying 25 entries per page.
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
Differentiation of Scots pine heartwood and sapwood by near infrared spectroscopy
2003 - IRG/WP 03-10459
In Scandinavia Scots pine heartwood has, in recent years, gained popularity as material for external structures exposed to moderate risk of decay. As non-durable sapwood surrounds the heartwood in pine trunks it is of crucial importance to separate this wood from the heartwood during log processing into heartwood products. Heartwood and sapwood can be differentiated by visual evaluation of colour ...
P O Flæte, E Ystrøm Haartveit
The accelerated L-joint test method for determination of the out of ground natural durability
1998 - IRG/WP 98-20146
The accelerated L-joint test incorporates a moistening device and uses a close end water trap in an open joint connection with a laminated tenon member consisting of the perishable reference wood species scots pine sapwood and beech.
After one year of exposure it is possible to show a distinct identification of natural durability classes 4 and 5 against the more durable wood species. Both weight ...
J Van Acker, C Brauwers, M Stevens
Standardization of CCA treated 45 hardwood species grown in Bangladesh for REB crossarms
1995 - IRG/WP 95-20059
Researches on 45 hardwood species grown in Bangladesh regarding density, moduli of rupture (MOR), colour and treatability of sapwood and heartwood, seasoning property and natural durability of heartwood revealed that both sapwood and heartwood of 17 species could be full cell pressure treated with CCA at impregnation pressure of 14-18 kg/cm² and only sapwood of rest 28 species could be pressure t...
A K Lahiry
Eradication of wood decay fungi by means of radio frequency
1998 - IRG/WP 98-10292
High frequency electromagnetic fields i.e. radio frequency (RF) are used in wood industry for heating, gluing and bending of wood and are also appropriate for eradicating of wood decay fungi and insects. We investigated the effects of RF exposure on wood samples which were in vitro infected by Coniophora puteana, Gloeophyllum trabeum and Lentinus lepideus. For each fungus, the lethal temperature a...
F Pohleven, J Resnik, A Kobe
An aquaria test of the natural resistance against marine borers of some commercial timbers available in Australia
1996 - IRG/WP 96-10145
The natural resistance of the heartwood of 22 different timbers grown or commercially available in Australia was examined. Radiata pine sapwood both untreated, and treated with 5.4 kg/m³ CCA salt, was included for comparison. Small timber blocks were exposed for one year in tanks containing either Limnoria tripunctata or Lyrodus pedicellatus. Four softwood species tested were heavily attacked and...
L J Cookson
The preventive effectiveness of preservative treatments against wood-rotting fungi. Preliminary results
1992 - IRG/WP 92-2407
The efficacy of a range of preservative treatments in preventing colonisation by decay fungi has been assessed using a method developed at BRE and similar to that adopted by Working Group 9 of European Standards Committee CEN/TC 38. Assessment was made using baits inserted into the test blocks, in holes which had been drilled after treatment to within defined distances of the treated face exposed ...
J K Carey
Possible durability transfer from durable to non durable wood species. The study case of teak wood
2001 - IRG/WP 01-10392
Teakwood is well known for its excellent natural durability, mostly due to its high proportion of extracts. Amongst these extracts, quinones, and more precisely some naphtoquinones (such as lapachol) and anthraquinones (such as tectoquinone) appear to play a crucial role in the resistance to wood decay organisms. At a laboratory scale, sawdust from malaysian teak heartwood has been extracted under...
M-F Thévenon, C Roussel, J-P Haluk
Basidiospore germination threshold against borate in-vitro may vary between liquid and agar media
1992 - IRG/WP 92-2405
The concentration of disodium octaborate (BAE) which prevented mycelial growth of a common brown rot and 3 white rot fungi was compared to that required to prevent basidiospore germination on malt extract agar. Spore germination sensitivity was lower (50%) for only one of the white rot fungi. However, when spore germination thresholds were tested in malt extract-borate solutions in well slides (no...
E L Schmidt, Ya-Lih Lin
The natural durability of five Indonesian timber species against marine borers - A field test in Indonesia
1981 - IRG/WP 474
This paper presents results of a natural durability field test using five species of Indonesian timbers against marine borers. An attempt is also made to assess any difference in durability between the lower and upper part of the trunks. Results of marine fungal identification, soft-rot assessment, and marine-borer assessment of CCA-treated test blocks will be reported in separate papers...
Suhirman, R A Eaton
Imaging fungal deterioration of wood using x-ray microtomography
1997 - IRG/WP 97-10240
Nondestructive tomographic images of solid Southern yellow pine (SYP) wood and SYP during deterioration by wood decay fungi were obtained by using a new class of synchrotron X-ray computed microtomography (CMT). The CMT images will provide information about spatial relationship between degrading fungi and wood structures. Wood samples were scanned with synchrotron-generated X-rays at high resoluti...
B Illman, B A Dowd
Effects of chemical pretreatment of Douglas-fir heartwood on efficacy of potential bioprotection agents
1990 - IRG/WP 1440
Biological protection against wood decay fungi represents an environmentally attractive alternative to the use of chemicals; however, the process of identifying suitable candidates and the conditions that ensure successful protection pose major challenges. One critical aspect of this problem is to identify organisms that can rapidly and uniformly colonize the wood. Wood contains low levels of nutr...
B Dawson-Andoh, J J Morrell
The role of oxygen and oxygen radicals in one-electron oxidation reactions mediated by low-molecular weight chelators isolated from Gloeophyllum trabeum.markup
1994 - IRG/WP 94-10086
The KTBA assay for determination of one-electron oxidation activity was used to assay reactions of low-molecular weight chelators isolated from the brown rot fungus Gloeophyllum trabeum. The assay, performed either under air or nitrogen showed that molecular oxygen was an important factor in chelator-mediated oxidation reactions. A reduction in oxidative activity was observed when superoxide dismu...
Jun Lu, B Goodell, Jiang Liu, A Enoki, J Jellison, H Tanaka, F Fekete
Effects of the specimen position on fungal colonisation and wood decay by en 113 test fungi
1998 - IRG/WP 98-20136
For testing wood preservatives according to EN 113 it is common practice to plant the test blocks on neutral supports in order to prevent (1) a diffusion of chemicals into the agar medium and (2) an excessive moistening of the specimens. The procedure was employed in EN 350-1 for testing the natural durability of solid wood.
It turned out to be of problematic nature because of the individual requ...
G Kleist, M-T Lenz, R-D Peek
European standardization for wood preservation. Progress report 91-92
1992 - IRG/WP 92-2398
Since the IRG 22 conference in Kyoto, CEN/TC 38 Plenary met twice in relation with several working group meetings. 5 upon 6 of the interpretative documents have been prepared by adhoc groups of the Standing Committee for Construction within the scope of the 89/106/EEC directive on Construction Products. The expected requirements attached to wood preservation are both requirements 1) and 3): 1) mec...
R Hüe
The influence of extractives on the natural durability of selected Ghanaian hardwoods
2004 - IRG/WP 04-10530
A study of the durability of Nauclea diderrichii, Nesogordonia papaverifera, Corynanthe pachyceras and Glyphaea brevis in laboratory and field tests showed the first three species performed well against a range of fungi and termites. Sapwood of C. pachyceras also performed well against these biodeteriogens. The role of extractives in conferring natural durability was assessed. Total extractive con...
C Antwi-Boasiako, A J Pitman, J Barnett
Cleistanthus collinus (Roxb.) Benth. ex Hook. f. and Wrightia tinctoria (Roxb.) R. Br. -- two timbers with promising durability under marine conditions
2005 - IRG/WP 05-10552
During the course of natural durability studies on indigenous timber at Visakhapatnam harbour, two species, namely, Cleistanthus collinus (Karada) and Wrightia tinctoria (Dudhi) were found to resist marine borer attack for reasonably longer periods. The panels of C. collinus completely resisted borer attack for 9 months but became susceptible to teredinid attack thereafter. The teredinids gradua...
M V Rao, M Balaji, V Kuppusamy, K S Rao
Uptake of copper by mycelium of wood decay fungi growing on copper S-substituted thioglycolate containing nutrient media
1998 - IRG/WP 98-10291
Mycelia of Trametes versicolor, Coniophora puteana and Poria monticola were grown on potato dextrose agar (PDA) media, containing various concentrations of copper N,N-dimethyldithiocarbamoylacetate (which may be regarded as a copper S-substituted thioglycolate). The tested copper compound revealed relatively low fungicidal activity. After 13-18 day growing period, we determined concentrations of a...
M Humar, M Petric, F Pohleven, P Kalan
Wood preservation research in Tanzania: Priorities and challenges
1988 - IRG/WP 3462
Tanzania provides some of the highest rates of wood deterioration in service leading to alarming economic losses and yet no serious concern is shown in search for solutions to the problem. The paper attempts to point out some of the priority areas in the field of wood preservation research that demand urgent attention if timber is to be used judiciously in this country. An account is given of the ...
K K Murira, R Cockcroft
Treatment groups and remedies for CCA treated hardwood and softwood poles
1999 - IRG/WP 99-40142
Different hardwood and softwood species from Bangladesh and Bhutan was investigated regarding density, green fiber stress, natural durability of heartwood and CCA treated sapwood, CCA treatability grades, sapwood thickness, and kiln-drying properties for long term use as electric poles. These properties along with the past service records for nineteen years, separated ten heardwood and five softwo...
A K Lahiry
Potential toxicants for controlling soft rot in preservative treated hardwoods. Part 2: Laboratory screening tests using sawdust
1977 - IRG/WP 2101
A technique is described for the rapid screening of toxicants against microorganisms, represented by the brown rot, Gloeophyllum trabeum, and a natural inoculum from soft rotted wood. Sawdust, in this case from sapwood of Eucalyptus maculata, is pretreated with the candidate formulation and moistened before inoculation. Visual scoring of growth can be used to discriminate suitable candidates as ea...
J D Thornton
Information from the COIPM wood group. (With Appendix: Préserver les matériaux en milieu marin sauvegarder l'environment marin telles sont la vocation et la mission du C.O.I.P.M.)
1989 - IRG/WP 4156
During the last COIPM Meeting, up to date information on cooperative work to test the resistance of plastic wrapping for pilings were submitted and discussed. In 1986 untreated wood samples wrapped with shrinkable polyolefin sleeves were submerged in 9 stations, situated in temperate and tropical waters. After 1 or 2 years of immersion the samples showed no sign of penetration by marine borers and...
A Gambetta
Screening of fungal strains for wood extractive degradation
1998 - IRG/WP 98-10254
Fungal strains were screened for their ability to degrade apolar extractives in wood from scots pine. The degradation of total wood extractives by 91 different strains was monitored in stationary batch assays incubated for 6 weeks. The results obtained show that the ability of wood-inhabiting fungi to utilize wood extractives varied greatly, even for different isolates of the same species. Fungal ...
J Dorado, M J Martinez-Inigo, T A van Beek, F W Claassen, J B P A Wijnberg, R Sierra-Alvarez
Preliminary investigation on the natural durability of Guayule (Parthenium argentatum)-based wood products
2000 - IRG/WP 00-40154
Conventional preservatives used to protect wood from insect and microbial damages are presently of major concern to human health and the environment. Finding alternative and economical preservatives has not been successful. Previous studies have shown that the resinous material extracted from the guayule plant (Parthenium argentatum, Gray) has both insect- and microbial-resistant properties. Unfor...
F S Nakayama, P Chow, D S Bajwa, J A Youngquist, J H Muehl, A M Krzysik
An analysis of the effects of some factors on the natural durability of pine (Pinus sylvestris L.) and spruce (Picea abies Karst.)
1986 - IRG/WP 1279
The effects of some factors on the natural resistance of pine and spruce sapwood against fungal decay and against attack of house-longhorn beetle larvae have been studied in laboratory tests and the results are evaluated by analysis of variance and regression analysis. Following conclusions were reached: Wood from summer-felled trees did not have a lower inherent natural durability against fungal ...
J B Boutelje, T Nilsson, S Rasmussen