Your search resulted in 236 documents. Displaying 25 entries per page.
The influence of the natural extractives of opepe (Nauclea diderrichii) and African padauk (Pterocarpus soyauxii) timbers on their durability
1996 - IRG/WP 96-30098
Many timbers contain chemical extractives that undoubtedly play a key role in the timber's natural durability. Opepe (Nauclea diderrichii) and padauk (Pterocarpus sp.) are both very durable timbers (class 1), yet they are described as being moderately permeable. This suggests the presence of biocidal chemicals within these timbers, rather than simple blocking agents. Initial trials on the...
E D Suttie, R J Orsler
Fungal-termite associations in the natural resistance of selected eucalypt timbers
1978 - IRG/WP 173
Butt billets of Eucalyptus regnans F. Muell., Eucalyptus grandis W. Hill ex Maiden, and Eucalyptus camaldulensis Dehnh., showing no visible signs of decay, were examined for the presence of fungi in outer, middle and inner heartwood. Fungi obtained in pure culture were characterized. Eucalyptus regnans yielded Cytospora eucalypticola van der Westhuizen, Trichoderma harzianum Rifai and Penicillium ...
D B A Ruyooka
Soft rot test of copper/chrome/arsenic treated heartwood of three Malaysian timbers
1991 - IRG/WP 2381
Standardized heartwood blocks of kempas (Koompassia malaccensis), keruing (Dipterocarpus sp.) and tualang (Koompassia excelsa) were impregnated with 0 to 6.3% (w/v) CCA and challenged to decay by a mixed inocula of Chaetomium globosum, Glenospora graphii, Humicola grisea, Petriella setifera and Trichurus spiralis in a containerized vermiculite-burial decay system according to draft CEN/TC 38 WG 4....
A H H Wong, R-D Peek
Natural Durability of Tropical Species – Variations and Prospects
2005 - IRG/WP 05-10568
The tropical timber resources of the world play an unequivocal role in economic development of both the tropical timber producing and importing regions. This paper describes natural durability as an important and preferred wood quality of tropical species of the world with emphasis on Malaysian hardwoods, the link between various aspects of tropical hardwood durability, hardwood utilization and bi...
A H H Wong, Yoon Soo Kim, A P Singh, Wang Choon Ling
Observations on the effect of two preservatives on settlement and development of the marine wood-borer Martesia striata L
1983 - IRG/WP 498
Small heartwood specimens of three tropical hardwoods namely kusia or opepe (Nauclea diderrichii (De Wild) Merrill), emire or idigbo (Terminalia ivorensis A. Chev.) and subaha or abura (Mitragyna stipulose (D.C.) O. Kuntze) were treated with either creosote (BSS 144 type) or a copper-chrome-arsenic preservative and submerged in the sea at Tema, Ghana. They were regularly cleaned of fouling and obs...
J E Barnacle, F F K Ampong
A prototypical needle-incisor for refractory timber
1995 - IRG/WP 95-40041
A needle-incisor was manufactured for trial. This machine has an incising mechanism that a set of needles held by a rotary plate incises timber which is moved toward the front simultaneously, and then another set of needles incises a new part of the timber. Timber is incised by recycling the process. Timber incised of 4400 incisons/m² with the depth of 56 mm by 2.8 mm-diameter needles on all the ...
A Yakuwa, H Endoh, M Mori, S Doi
Will political initiatives stop the use of preservative-treated wood in Sweden?
1990 - IRG/WP 3578
The Swedish government has initiated several investigations on how to reduce the use of different chemicals. Among these chemicals are creosote, arsenic, chromium and organotin. A special investigation was carried out concerning wood preservatives resulting in different proposals on how to reduce the use of preservatives and preservative treated wood. The most important proposals were an "environm...
J Jermer, M-L Edlund
A method for the preliminary assessment of timbers for their treatability with preservatives under pressure
1977 - IRG/WP 3100
President Maurice Fougerousse has provided the following references to a IUFRO report, published in English, French and German, which may be of interest to IRG members:
'A method for the preliminary assessment of timbers for their treatability with preservatives under pressure', PANS Vol 23, No 2, 153 158, June 1977.
'Une methode d'evaluation preliminaire de l...
M Fougerousse
Microbial decay of an archaeological wood
1994 - IRG/WP 94-10053
A light and transmission electron microscopic investigation of an archaeological wood was undertaken to determine the cause of its deterioration. The wood came from a bulwark constructed in early 1100 in the lake Tingstäde Träsk on the island Gotland in Sweden. The samples of the wood, which was identified as Pinus sylvestris, were taken from a depth of 0.85 m below the bottom level. The wood wa...
A P Singh, T Nilsson, G F Daniel
The natural durability story
1997 - IRG/WP 97-20119
Wood species with superior natural durability were in use since the beginning of timber utilisation. Their importance decreased with increasing industrial timber impregnation. In recent time, however, they gained worldwide new interest due to environmental problems involved with treated timber. In Europe a special Standard (EN 350) has been published and a multinational research project on testing...
H Willeitner, R-D Peek
Statistical evaluation of 'micro-bending' samples for classification of wood attacking fungi
1992 - IRG/WP 92-1544
Micro-specimens from both hardwood and softwood were exposed to selected species of field isolated fungi. The strength reduction and weight loss caused by these fungi were determined. A statistical procedure was then developed to classify the fungi into brown-, white-rot, or non-decay fungal categories based on these data. The procedure reveals the extent of hazard a fungus poses to wood members. ...
B Goodell, Jing Liu, A Homola, J Jellison, J Shottafer
The practice of using concrete on wood piling for marine use in Thailand
1982 - IRG/WP 492
The practice of using concrete on wooden poles has been carried on in Thailand for a long time in pile-houses and pier constructions which have been situated in, or partly in the sea. In such instances, the hewed round and/or square-sawn heartwood poles of naturally durable timber species have been coated with concrete of about 5 to 10 cm or more in thickness, and to about 100 cm above the highest...
B Anuwongse
Discoloration of pressure impregnated wood caused by Amorphotheca resinae
1990 - IRG/WP 1438
Amorphotheca resinae Parbery with the anamorph Cladosporium resinae (Lindau) von Arx & de Vries is a cosmopolitan fungus known from aviation kerosene, hydrocarbon contaminated soil and creosoted timbers. In Denmark it causes heavy discoloration on wood treated with waterborne chromate-containing preservatives e.g. CCA-oxide type. The teleomorph produces small spherical fruitbodies widespread o...
F Rune, A P Koch
Resistance of various wood species against decay by Coniophora cerebella (Pers) Duby and Lenzites trabea (Pers) Bres
1976 - IRG/WP 142
Both fungi, Coniophora cerebella and Lenzites trabea, are important destroyers of timber. Coniophora often occurs inside buildings and Lenzites trabea has been observed on southern facades of buildings, on balconies and window frames. In most instances that we investigated coniferous timber had been decayed. But both species are known to attack also various hardwoods. For this reason tests similar...
O Wälchli
Lignicolous marine fungi from panels of different timbers exposed along Goa coast (India)
1993 - IRG/WP 93-10037
Colonisation by marine fungi on panels of thirty species of Indian timbers, ten species of imported timbers, marine plywood (coated with polyurethane as well as uncoated) and also on panels of five timber species treated with Copper-Chrome-Arsenic (CCA) and Copper-Chrome-Boric (CCB) preservatives, was studied by exposing test blocks in the Mandovi estuary, Goa (West coast of India) for periods ran...
L N Santhakumaran, S Chinnaraj, S G Sawant
Natural resistance of timbers to marine borer attack. A laboratory test with Limnoria tripunctata
1977 - IRG/WP 430
Attack of the timber specimens was much less severe in the laboratory than in some marine localities. This is not surprising. One reason is certainly that wood-boring molluscs (Teredinidae and Pholodidae) which were missing in the laboratory are the most important wood-destroying organisms in the open sea. Another reason is that it is not possible to offer the gribbles optimal environmental condit...
H Kühne
The natural durability assessments of secondary timber species - field trials
1998 - IRG/WP 98-10297
Secondary or 'alternative' hardwood timber species can replace traditional hardwoods and contribute significantly to satisfying the overall demand for hardwoods in the UK timber market. A selection of these 'alternative' hardwoods is currently being tested at BRE-WTC for natural durability both in ground contact (to EN252) at two field sites, and out of ground c...
E D Suttie, R J Orsler
Soft rot
1978 - IRG/WP 179
Soft rot decay of treated wood is examined with special reference to hardwoods treated with CCA. Factors which adversely affect the chances of protection of hardwoods against soft rot are discussed. The ratio of the volume of the fibre cell wall to the volume of the fibre lumen is presented as a major factor influencing final preservative concentration in the fibre cell wall, the major strength co...
C R Levy
Fungi causing sap stain in wood
1980 - IRG/WP 199
The present paper is a revised edition of former Document No: IRG/WP/125. It contains some additions and an explanation of terminology, as was suggested at a previous meeting of the Group. The paper is a compilation based mainly on available literature. Some of my own unpublished results have been added together with other unpublished data which have been received from the Bundesanstalt für Mater...
A Käärik
Venezuelan net of test fields for the study of the effectiveness of treatments of non commercial timbers from natural tropical forests
2005 - IRG/WP 05-20318
A net of 13 tests fields were established in Venezuela for the study of the effectiveness of the CCA and CCB treatment in secondary or non commercial woods from natural forests, two woods from fast growth plantations wee included for promote them as treated timber mainly for fence posts uses. Partial results after two years are presented and discussed the preliminary results obtained both in field...
O Encinas, N Mora
Natural durability of fifty species of Indian timber in Goa waters against marine wood-borers
1989 - IRG/WP 4150
Results of the investigations on the natural durabilitv of fifty species of Indian timber, based on data collected bv exposing test panels at Betim near Panaji (Goa) continuously for a period of 11 months are presented. The study revealed that none of the timber species tested has any natural resistance at this locality and all the panels were completely destroyed within 11 months. Details on the ...
L N Santhakumaran, S Udaya Bhaskar, J C Jain
Performance of preservative-treated timber against biodeterioration in Indian waters
1984 - IRG/WP 4106
Results on the investigation on the durability of panels of 32 timber species, pressure-treated with various preservatives and exposed along the Indian coast for varying periods upto a maximum of 15 years, are summarised. Panels of even non-durable timber gave excellent results against biodeterioration after treatment. Their life was comparable to that of treated durable timber. The preservative t...
L N Santhakumaran, J C Jain, M C Tewari
Bacteria are important degraders of cooling tower timbers: New Zealand experience
1995 - IRG/WP 95-10128
Microscopic examinations of CCA-treated Pinus radiata timbers in industrial cooling towers in New Zealand showed bacteria and soft rot fungi to be primarily responsible for the decay of these timbers. Of these micro-organisms, erosion bacteria appeared to be most widespread, attacking wood cell walls independently as well as together with tunnelling bacteria and soft rot fungi. Tunnelling bacteria...
A P Singh, R N Wakeling
Laboratory evaluation of termite resistance of five lesser-known Malaysian hardwoods used for roof and ceiling construction
2001 - IRG/WP 01-10398
The general laboratory procedure of AWPA E1-97 was used to evaluate the termite resistance of 5 lesser- known species (LKT) of Malaysian hardwoods: Kekatong (Cynometra sp.), Kelat (Eugenia spp.), Mempening (Lithocarpus spp.), Perah (Elateriospermum tapos) and Pauh Kijang (Irvingia malayana) against the subterranean termite Coptotermes curvignathus over 28 days. Kempas (Koompassia malaccensis) and ...
A A H Wong, Kee Suan Cheok, J K Grace
Wharf-borer a threat to stored archaeological timbers
1992 - IRG/WP 92-1560
Increased interest in marine archaeology has occured in recent years. Stored waterlogged archaeological timbers have been shown to be degraded by physical and microbial agents. In recent years a new threat has been highlighted, namely the wharf-borer Nacerdes melanura (L.). The objective of this paper is to outline studies of the morphology, biology, life-history and carbohydrate digestion by this...
A J Pitman, E B G Jones, A M Jones, M Rule