Your search resulted in 229 documents. Displaying 25 entries per page.
The Relationship of Fiber Cell Wall Ultrastructure to Soft Rot Decay in Kempas (Koompassia malaccensis) Heartwoo
2004 - IRG/WP 04-10541
The ultrastructure of fiber walls in kempas (koompassia malaccensis) heartwood was examined in relation to soft rot cavity formation. The fibers consisted of middle lamella and thick secondary wall. The secondary wall was differentiated in to a S1 layer, and a unique multi-lamellar S2 layer. Two distinct forms of lamellae were recognisable, one type being considerably thicker than the other. They ...
A P Singh, A H H Wong, Yoon Soo Kim, Seung-Gon Wi
Observations on the uptake and penetration of various liquids in clear heartwood and sapwood of Pinus radiata D.Don
1983 - IRG/WP 3224
Volumetric uptake of water (aqueous copper-chrome-arsenic (CCA)) or methanol, applied by bulk hydrostatic pressure to air dried clear heartwood specimens of Pinus radiata D. Don, far exceeds that of a wide variety of polar and non-polar solvents. In air dried sapwood, the volumetric uptake of CCA tends to be less than that achieved for most solvents including methanol. No comprehensive explanation...
J E Barnacle
Leaching of copper, chromium and arsenic from CCA-treated slash pine heartwood
1994 - IRG/WP 94-50020
Drying green slash pine with any of three high temperature drying schedules produced a product in which both the sapwood and the heartwood could be penetrated with CCA using a modified Bethell treatment schedule. Required H3 retentions were achieved in both sapwood and heartwood, from 200 litres per m³ charge uptake. Post-treatment fixation/drying was accomplished by three different regimes, incl...
M J Kennedy, G Palmer
Effects of boron treatments on partially decayed oak and pitch pine heartwood
1996 - IRG/WP 96-30106
This paper reports results of borate based preservative treatment and leaching experiments on partially decayed oak and pitch pine heartwood. Previous experiments have shown little damage is caused to sound timber of these types when treated with Polybor and Boracol 20 preservatives. This experiment was carried out to assess the suitability of selected borate based preservatives for use in histori...
S McCutcheon, G M Smith, J W Palfreyman, P Durrant
The chemical analysis and biological evaluation of wood extractives as potential timber preservatives
1995 - IRG/WP 95-30090
Work involved the biological performance of water and organic solvent soluble extractives of four naturally durable wood species, namely; Matumi, Tamboti, Sneezewood and the Turpentine tree. These timber species are known to be naturally durable against termites and fungi (±25 to 35 years). The extractives were evaluated against termites and fungi using impregnated pine pencil stakes in field tes...
P Turner, D Conradie
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
Natural durability of Iranian saxual wood (Haloxylon persicum) against the fungal decay
1991 - IRG/WP 1515
Haloxylon persicum is vidly planted in the deserfic region of Iran. At the present time, in the age of 30, these small trees are ready for cutting for the different uses, specially for rural buildings. But there's any knowledge about its durability. In this study the laboratory tests were carried out in accordance to European Standard. 5 fungi were used as: Trametes versicolor, Coniophora...
D Parsapajouh, F H Schweingruber, K Richter
Soft rot studies on CCA treated eucalypt power transmission poles
1981 - IRG/WP 1132
Initial results found for sixty CCA treated eucalypt poles, from a soft-rot survey are discussed. Retentions of CCA within above and below ground pole samples were variable. The variation was attributed mostly to biodegradation and effect of soil environment, rather than leaching. Bacterial decay was found in many poles and was severe in some cases. Although found in the presence of soft-rot decay...
L E Leightley
Relationship between bond strength and surface characteristics of CCA-treated Douglas-fir
1993 - IRG/WP 93-30008
Chromated-copper-arsenate (CCA) treated Douglas-fir was laminated using a commercial phenol-resorcinol resin. CCA treatment enhanced the water repelleney of wood espeeially in the presence of extractives. However, the shear strength of CCA treated wood was 12% lower in dry condition and 38% lower in wet condition after six cycles of vacuum-pressure test than that of untreated wood. Slight removal ...
K Yamamoto, J N R Ruddick
An in-ground natural durability field test of Australian timbers and exotic reference species. Part 5: Extensive data from a site where both decay and termites are active. Results from a full-replicated set of heartwood specimens from each of ten myrtaceous hardwoods after 18, 19 and 20 years' exposure - A discussion paper
1988 - IRG/WP 2324
Extensive data are presented on the decay situation, the termite situation and the decay-termite associations; all gathered from a fully-replicated set of heartwood specimens of 10 hardwood timbers after 18, 19 and 20 years' exposure in the ground at a single test site, i.e. a semi-arid steppe site. Sixteen tables are presented in addition to the one table providing the rating data; the l...
J D Thornton, G C Johnson, J W Creffield
UV-microspectrophotometry of lignin and accessory compounds in wood cell walls of conifers
1999 - IRG/WP 99-20171
The distribution of lignin in the cell wall of conifer tracheids was determined by UV-VIS microspectro-photometer. Wood sections of one micron thickness were measured between the wavelength 240 and 700 nm. Spectral analyses revealed that the conifer lignin associated with the tracheid secondary wall and middle lamella is composed of guiacylpropane units which exhibit a characteristic UV absorption...
G Kleist, G Koch, J Bauch
Bioassays of extracts from scaly ash (Ganophyllum falcatum B1) against the subterranean termite Coptotermes acinaciformis (Froggatt)
1983 - IRG/WP 1206
Scaly ash, Ganophyllum falcatum B1. wood shavings were extracted by methanol, and fractionated with ethyl acetate, diethyl ether and water, and the anti-termitic properties of these materials bioassayed against the subterranean termite Coptotermes acinaciformis (Froggatt). Laboratory techniques were developed to overcome the problem of limited extractive materials. The results of the various bioas...
J R J French, J P Robinson, J W Creffield
The effect of wick action on the moisture distribution in heartwood and sapwood stakes of Pinus radiata D. Don.
1999 - IRG/WP 99-40139
The pattern of moisture distribution in stakes of Pinus radiata D. Don. subjected to "wick action" is investigated. There was incomplete saturation of the stakes even after 93 days of continual soaking. Maximum moisture absorption occurred at the base of the stake and at the air/water interface of the stake. Incomplete saturation of the stake was thought to be due to air embolism within the wood. ...
J Hann, P Vinden
Diffusion of a copper naphthenate/boron paste through Douglas fir heartwood
1991 - IRG/WP 3671
Groundline wraps are an important portion of the remedial treatment strategies for protecting utility poles in North America from surface decay. The compositions of these wraps have recently shifted away from pentachlorophenol and creosote to formulations containing copper naphthenate and boron. These formulations have not yet been extensively tested, although the chemicals have been used for many...
P G Forsyth, J J Morrell
The influence of wood moisture content on the fungitoxicity of methylisothiocyanate in Douglas fir heartwood
1987 - IRG/WP 3430
The fumigant methylisothiocyanate (MIT) effectively controls decay fungi in large wood structures, but the influence of environmental factors on its performance are not well understood. Experiments found wood moisture content to greatly influence the fungitoxicity and sorption of MIT in Douglas fir heartwood. At constant, low MIT vapor concentrations (less than 1 µg/cc air), wood at 10% MC bound ...
A R Zahora, J J Morrell
Presteaming radiata pine heartwood to improve treatability
1983 - IRG/WP 3239
Steaming and holding before preservative treatment by the Bethell process greatly improved the treatment of radiata pine heartwood. Maximum penetration of preservative for the shortest holding period was obtained by the use of steam vacuum but the difference between this and steam venting was small when compared with the standard of treatment of air dried samples. A holding period of one day was s...
A J Bergervoet
Wood extractives as carbon sources for staining fungi in the sapwood of lodgepole pine and trembling aspen
1995 - IRG/WP 95-10098
Wood discoloration by sapstaining fungi reduces lumber value. In Canada, the most commonly recorded sapstaining fungi belong to the genera Ophiostoma. This work evaluated the effect that Ophiostoma piceae, Ophiostoma ainoae, and Ophiostoma piliferum used the lipids present in the sapwood of lodgepole pine (Pinus contorta Dougl.) and trembling aspen (Populus tremuloides Michx.). Wood lipids, common...
Yong Gao, C Breuil
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
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
Internal pressure monitoring during the treatment of Pinus radiata (D. Don)
1995 - IRG/WP 95-40049
The use of micro-transducers to monitor the internal pressure of wood during treatment is investigated. The rates of pressure transfer in radiata pine sapwood and heartwood are compared during Bethell treatment with copper chrome and arsenic preservative. The effect of pre-conditioning treatments are also evaluated using micro-transducer monitoring. It is anticipated that knowledge of the changes ...
P R S Cobham, P Vinden
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
Effect of angle of exposure on degradation of radiata pine during weathering trials
1988 - IRG/WP 2301
The importance of angle of exposure on the degree of weathering of materials has not been adequately resolved. In conventional tests, specimens are exposed at an angle of 45° facing the equator, but more recently experiments on polymeric materials have suggested that an angle of 0° may be preferable since this angle maximises levels of received ultra-violet radiation. In this paper the degradati...
P D Evans
Termite resistance of Malaysian and exotic woods with plantation potential: Laboratory evaluation
1998 - IRG/WP 98-10280
The resistance of selected Malaysian woods to attack by the representative aggressive subterranean termite Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae) was evaluated in four-week, no-choice laboratory tests. This is part of an ongoing effort between the Forest Research Institute Malaysia and the University of Hawaii to document the termite resistance of Malaysian timber species of po...
J K Grace, A A H Wong, C H M Tome
An investigation of the effects of pre-steaming on the treatment of sawn spruce timber with Celcure A, a copper/chrome/arsenic preservative
1981 - IRG/WP 3180
Difficulties in the treatment of spruce using standard vacuum/pressure techniques with both water-borne and organic solvent preservatives are well known. The growth characteristics of spruces (Picea spp) make them attractive candidates for forestry schemes. In 1975 the UK Forestry Commission had about 400 000 hectares, about 20% of total UK forest area, planted with Sitka spruce (Picea sitchensis)...
C R Coggins
Effect of extractive fractions of Thuja plicata and Chamaecyparis nootkatensis heartwood on Coptotermes formosanus
2004 - IRG/WP 04-10535
Heartwood of some species has natural resistance to attack by termites due to the presence of toxic and/or repellent extractives, but the role of individual extractives in termite inhibition is poorly understood. Developing a better understanding of which extractives are most effective against termites may be useful for the identification of improved termite management strategies. The effect of se...
A Taylor, B L Gartner, J J Morrell, K Tsunoda