Your search resulted in 115 documents. Displaying 25 entries per page.
The effect of certain wood extractives on the growth of marine micro-organisms
1977 - IRG/WP 438
S E J Furtado, E B G Jones, J D Bultman
Chemical compounds from Eperua falcata and Eperua grandiflora heartwood and their biological activities against wood destroying fungus (Coriolus versicolor)
2005 - IRG/WP 05-30373
The chemistry analysis of the compounds present in dichloromethane and ethanolic fraction as well as bioassays enables to understand the durability differences of Eperua falcata and Eperua grandiflora. The principal distinction between these two species is the acidic subfraction of diterpenoic extract, which is antifungic in Eperua falcata when tested in in-vitro conditions. This study also enables to show that ethanolic fraction plays an important role in the mechanism of natural durability. It also reports the first isolation of cativic acid in Eperua falcata wood.
N Amusant, C Moretti, B Richard, E Prost, J M Nuzillard, M-F Thévenon
Methodology challenges in developing a transfer of natural durability from sawmill residues, illustrated by experiences with white cypress (Callitris glaucophylla)
2000 - IRG/WP 00-20203
The transfer of durability-conferring extractives from durable to non-durable wood has been accomplished often, but usually as an educational exercise rather than as a commercially oriented process. In the latter environment, many factors previously overlooked become vitally important. How to study them, in the absence of well-developed methodology and given the shorter timeframes being demanded by industry research funding organisations, presents real challenges. These challenges will be illustrated by experiences with the development of such a process for the 'waste' durability components of white cypress. Factors to be considered include: identification of active components; quantification of their individual and collective activities against target organisms; optimisation of source material handling, storage and extraction techniques; extract standardisation and batch-to-batch reproducibility; compatible yet cost-effective carriers for the actives into treated wood; effects on durability and other wood properties such as strength and handling safety; regulatory obstacles including acceptance into wood preservation standards; and quality control methods for penetration and retention of the treated product.
M J Kennedy, M A Powell
Efficacy of some extractives from Pinus heartwood for protection of Pinus radiata sapwood against biodeterioration. Part 1: Fungal decay
1995 - IRG/WP 95-30072
Chemical compounds thought to contribute to the natural durability of heartwood of Pinus spp. were either chemically synthesised in the laboratory or extracted from the heartwood of Pinus elliottii or Pinus caribaea. These compounds included the stilbenes, pinosylvin and its mono- and di-methyl ethers, and the flavonoids, pinobanksin and pinocembrin. Small blocks of Pinus radiata sapwood were impregnated with methanolic solutions of pure compounds or heartwood extracts, to a range of retentions extending above and below the concentration of each compound known to occur in the heartwood of Pinus spp.. Fungicidal efficacy of these compounds has been evaluated by exposure of treated blocks to pure cultures of a white and a brown rot, in addition to an unsterile soil test.
M J Kennedy, J A Drysdale, J Brown
Estimation of service life of durable timber species by accelerated decay test and fungal cellar test
2002 - IRG/WP 02-20249
Many kinds of durable wood species for outdoor uses has been imported from all over the world to Japan. However information on the natural durability of these species is not sufficient to estimate the service life of them in the climate of Japan. Highly durable species such as Jarrh, Teak, Ipe, Ekki, Selangan batu, Red wood, Western red cedar showed no significant percent mass losses by accelerated decay test according to the JIS Z2101, but some of them are degraded during fungal cellar test for 4 years . The decay rating (0:sound to 5:totally decayed) of them after 4 years exposure was 1.0, 2.0, 0.0, 1.0, 0.0, 2.3, 5.0 respectively. This results indicated that the conventional accelerated decay test could not evaluate the natural durability of these highly durable species at all. Solid wood specimens treated with boiling water at 120? for one hour are subjected to the same JIS test, and the obtained percent mass losses of these species are 1.2, 2.9, 1.9, 3.8, 4.7, 17.5, 0.0 % by a brown rot fungus, Fomitopsis palustris, and 17.5, 14.3, 3.3, 8.2, 4.2, 0.0, 18.3 % by a white rot fungus, Trametes versicolor respectively. Pre-treatment of solid wood specimens for removal of heartwood extractives before a accelerated decay test would be an effective way to evaluate the natural durability of highly durable species in a laboratory.
K Yamamoto, I Momohara
About the relations between the natural durability of some tropical species and their extractives content
1983 - IRG/WP 1208
G R Y Déon
Co-operative research at the Naval Research Laboratory on wood extractives and related compounds as antiborer agents
1977 - IRG/WP 429
J D Bultman, K K Parrish
Autoxidation of beech condensate
2003 - IRG/WP 03-40261
Liquid effluent from steaming beech wood was studied. The effluent contains many phenolic compounds which can present a significant toxicity. The effluent was treated by oxidation was carried out at 250 rpm for 30 min with NaOH. This was followed flocculation with CaCl2 for 30 min. The influence of parameters such as pH, time of autoxidation were studied. Experimental results reveal the electrostatic interaction between the oppositely charged wood extracts after oxidation and flocculation. The increase in aqueous phase pH resulted in enhanced removal of wood extracts from water. The effect of pH is explained based on oxygen uptake.
M Irmouli, J P Haluk
Decay resistance of Scots pine (Pinus sylvestris) heartwood against brown rot
2002 - IRG/WP 02-10433
Natural decay resistance of wood is mainly restricted in the heartwood and based on wood microstructure and chemical composition. The genetic variation in the durability of Scots pine (Pinus sylvestris L.) wood against decay and the relationship between resistance and chemical composition was studied. The laboratory tests of 6 and 8 weeks were carried out with a brown rot fungus Coniophora puteana (Schum. ex Fr) Karst (strain Bam EBW 15). The increment core samples of sapwood and juvenile heartwood, obtained from about 30-year-old half-sib progenies, were decayed using a modification of the standardised EN 113 method. The average density of the sapwood was 391 mg/cm3 (one stand) and that of heartwood samples 337 and 376 mg/cm3 (two stands). The average mass loss of the sapwood samples was 114 mg/cm3 (6 weeks, stand 1) and that of the heartwood samples 80 mg/cm3 (6 weeks, stand 1) and 123 mg/cm3 (8 weeks, stand 2). The variation among heartwood samples was high. The additive genetic component was small in stand 1 but quite large in stand 2, which resulted in a low narrow sense heritability h2 in stand 1 (0.07) but high in stand 2 (0.37). New samples were taken from the most resistant and susceptible trees for chemical analyses. The concentration of resin acids was higher in the group of decay resistant trees than in the group of decay susceptible trees. About 90 % of the resin acids in the heartwood were of the abietane type, abietic acid being the most abundant.
H Viitanen, A M Harju, P Kainulainen, M Venäläinen
Effect of permeability and extractives on the decay rate of southern pine sapwood in above grund exposure
2005 - IRG/WP 05-20310
The effects of wood permeability and hydrophilic and hydrophobic extractives on the decay rate of southern pine sapwood in above ground exposure were investigated. Permeability was determined by water sorption measurements, and the effect of extractives was studied by pre-extracting the test samples prior to outdoor exposure using water to extract hydrophilic extractives or sequential methanol/cyclohexane extractions to remove hydrophobic extractives. Initial water permeability of the wood prior to outdoor exposure was highly correlated to decay rate, with the more permeable samples decaying more rapidly. Removal of the hydrophilic extractives prior to exposure decreased the decay rate, but the effect was not statistically significant at the 0.05 level. Conversely, removal of the hydrophobic extractives significantly increased the rate of decay, even though it had no effect on the initial water permeability.
D D Nicholas, T Schultz, L Sites, D Buckner
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 tests and soil burial trials over a 2 year period. C13NMR analysis of extractives isolated from the wood was carried out to try and identify the key chemical components which might impart durability with a view to prediction of new potential wood preservative formulations.
P Turner, D Conradie
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 of treated wood surface by planer or sander contributed for better adhesion, although it was not enough. The characteristics of treated wood surface was analyzed by X-ray photoelectron spectroscopy (XPS). CCA treatment increased C1 (C-H) and decreased C2 (C-OH), indicating migrated exctractives have enhanced the water repelleney of treated surface. The removal of hydrophobic surface of CCA-treated wood decreased C1 component of C1s spectra on the new surface.
K Yamamoto, J N R Ruddick
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 maximum at 280 nm. Therefore, in addition, ultrathin sections were exclusively scanned with this characteristic wavelength. Four examples of application are presented: (1) l the lignin contents of the different cell wall regions of fresh spruce wood, (2) the UV-characterization of highly lignified S2-layers in compression wood, (3) a specific pattern of lignin distribution and its derivatives during degradation by white-rot fungi and (4) the detection of accessory compounds (e.g. podocarpic acid) in the lumen and the cell walls of Podocarpaceae species. Finally, the prospects for actual research concerning detection of accessory compounds from hardwoods are given.
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 bioassays indicated that the most toxic extractives were cold methanol extract water solubles, and cold methanol insolubles.
J R J French, J P Robinson, J W Creffield
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, commonly known as extractives, consist mainly of triglycerides, fatty acids, resin acids, sterols, steryl esters and waxes. The sapwood of lodgepole pine and trembling aspen was rich in triglycerides. All the sapstaining fungi tested were able to degrade the triglycerides in both of the wood species very effectively. The fatty acids, steryl esters and waxes were used slowly, especially in lodgepole pine. The fungi could also decrease the level of resin acids in lodgepole pine.
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 location and role of the extractives are presented, including the changes in bioresistance of the extracted timber to laboratory pure strains of brown and white rot fungi. The extractives responsible for the enhanced durability are probably located within the cell wall and require polar solvents such as methanol or acetone to remove them. These solvents will be used in further extractive studies. This project forms part of a wider program of research concerned with novel approaches to wood preservation, based upon a detailed understanding of wood chemistry. The overall objective is to develop environmentally benign techniques for timber preservation.
E D Suttie, R J Orsler
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 biological hazards of different regions of the world, the resource evolution in the utilization of tropical hardwoods including the introduction of plantation-grown durable species and increased use of wood composites, a summary of research on the major cause of variations in natural durability of tropical hardwoods focusing on heartwood extractive bioefficacy, their microdistribution in relation to natural durability, and heartwood extractives as future sources of novel organic wood protecting chemicals. Recent advances in genetic manipulation of disease resistance in certain tree species makes it theoretically possible to genetically produce naturally durable tropical species with their accompanying inherent anti-microbial substances, which if/when realized, would provide significant opportunities to produce transgenic naturally durable species befitting a natural wood protection concept.
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 degradation of Radiata pine (Pinus radiata D. Don) during weathering was assessed at 5 angles of exposure (0°, 45°, 60°, 70°, 90°) over 50 days by measuring changes in weight and chemical composition. In order to confirm previous observations measurements of received ultra-violet radiation (< 320 nm) at these angles of exposure were also made using polysulphone polymer film dosimeters. Roth weight loss and chemical data indicate that degradation of Radiata pine during weathering was negatively correlated (p < 0.001) with increasing angle of exposure. The implications of these findings for the conduct of weathering trials are discussed.
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 potential value in plantation forestry. Several of these tree genera also occur in Hawaii, or could potentially be of value as well in forestry efforts in the Hawaiian islands. Species included in the present report are: acacia (Acacia mangium), batai (Albizia falcataria), casuarina pine (Casuarina equisetifolia), Araucarian pine (Araucaria cunninghamii), sentang (Azadirachta excelsa), both Malaysian-grown and Burmese-grown teak (Tectona grandis), kempas (Koompassia malaccensis), tualang (Koompassia excelsa), Caribbean pine (Pinus caribaea), Scots pine (Pinus sylvestris), and rubberwood (Hevea brasiliensis). Of these, Burmese teak, kempas, tualang, and casuarina pine proved most resistant to termite attack. Malaysian teak and sentang demonstrated somewhat less, but still significant termite resistance. Sentang is a relatively pest-free tree of interest for plantation forestry, and was also quite toxic to termites. The remaining tree species were very susceptible to termite attack, and would require protection in the field and treatment of the resulting wood products. Correlation of these laboratory results with data from field studies in Malaysia will provide a comprehensive profile of the termite resistance of these timbers.
J K Grace, A A H Wong, C H M Tome
Effects of alkali treatment on some mechanical and chemical properties of creosote treated oaks
1991 - IRG/WP 2366
To date, there is a lack of information on the effects of chemical treatment on the performance of creosote preservative treated oak sleepers. This factorial experiment was designed to analyze three main effects: species (Quercus alba and Quercus rubra) creosote treatment (treated and untreated), and alkali (NaOH) soaking (0, 1, and 10 percent). The modulus of elasticity (MOE) and fiber stress at proportional limit in compression perpendicular to grain, hardness modulus, surface hardness, alcohol-benzene extractives, hot-water extractives, 1% NaOH extractives, lignin, pentosans, holocellulose, and alpha-cellulose content were determined on specimens. The test results indicated that species, creosote treatment, and alkali soaking significantly affect both the mechanical and chemical properties of the oak sleepers.
P Chow, A J Reinschmidt, E J Barenberg, L C Chang
Biocidal screening method of wood extractives by a direct use of cellulose TLC plate
2001 - IRG/WP 01-20226
Most of the methods to evaluate the biological durability of woods have focused on decay fungi and termite as deteriorating organisms and it is well known that one of the most important factors affecting the biological characteristics of wood is extractives. Bioassays for evaluating the biological activities of wood extractives have been mainly conducted with treated filter papers for termites or extractives- containing agar media for decay fungi. Using these methods, the separation of crude extracts and bioassays are very time consuming. Thin layer chromatography (TLC) is a useful method for separating the mixture of organic compounds. It is also applicable to the crude extracts of wood consisting of many compounds. In TLC, silicagel, cellulose and other materials are used as stationary phases and we speculated that it would be to sepatare the crude extract on cellulose TLC plate (Cell - TLC) and directly apply it to bioassays, since termites and decay fungi can use the cellulose layer in Cell - TLC as their carbon sources. In this paper we report the applicability of Cell - TLC for biocidal screening of wood extractives against termites and decay fungi.
R Yusiasih, T Yoshimura, T Umezawa, Y Imamura
Durability of five wood species against Coriolus versicolor
1992 - IRG/WP 92-1578
The durability of following five wood species Zelkova carpinifolia, Ulmus glabra, Carpinus betulus, Acer trauvetteri and Pterocarya fraxinifolia were studied against Coriolus versicolor under laboratory conditions according to DIN 52176 standards. Zelkova caprinifolia shows a reduction in weight of 2.19%, Ulmus glabra 41.69%, Carpinus betulus 45.64%, Acer trauvetteri 53.05%, and Pterocarya fraxinifolia 43.08%. There was a negative correlation between decay and amount of extractive materials for all species except Pterocarya fraxinifolia.
S M Kazemi
The antifungal efficacy of Guayule resin
1987 - IRG/WP 3429
The Naval Research Laboratory is evaluating the non-rubber-producing portion of guayule (Parthenium argentatum) resin as a protectant for wood in terrestrial and marine service. This study phase, in collaboration with the universities of Arizona and Mississippi State, evaluates the resin's fungicidal worth. Resin-impregnated pine sapwood was exposed to brown rot fungi (Gloeophyllum trabeum, Antrodia carbonica, Formitopsis cajanderi, Lentinus ponderosa), white rot fungi (Dichomitus squalens, Trametes versicolor, Ganoderma sp.), and a natural inoculum of soft rot fungi from unsterile soil. The exposures for the brown and white rot fungi lasted 20 weeks, using malt agar chambers inoculated 2 weeks prior to the introduction of the treated wood; the soft rot exposure lasted 12 weeks and included treated birch specimens. Weight loss data showed a definite inhibition of decay of the treated wood by the brown and white rot fungi, however there was some decay caused by Lentinus ponderosa (closely related to creosote-tolerant Lentinus lepideus) and by Antrodia carbonica, a common utility pole fungus. None of the resin-impregnated pine or birch specimens were attacked by the soft rot fungi, even those specimens containing the lowest of the three resin concentrations in the wood. In both sets of exposures all of the controls were decayed.
J D Bultman, R L Gilbertson, T L Amburgey, J E Adaskaveg, S V Parikh, C A Bailey
Relationship of wood durability and extractives
2003 - IRG/WP 03-10493
The durability of the following five wood species, Zelkova carpinifolia, Ulmus glabra, Pterocarya fraxinifolia, Carpinius betulus and Acer laetum, were studied. Wood blocks were exposed to Coriolus versicolor under laboratory conditions according to DIN 52176 standard. After 16 weeks incubation the heart wood of Z carpinifolia showed 2,19 % weight loss, U glabra 41,69 %, C betulus 45,64 %, A laetum 53,03 % and P fraxinifolia 43,08 %. For finding relationship between durability and amount of wood extractives a regression analysis was carried out. The percentages of extractives (T20403-76 standard) were 13,84 % in Z carpinifolia, 4,51 % in U glabra, 2,74 % in C betulus, 3,88 % in A laetum and 4,11 % in P fraxinifolia. There was a negative correlation between decay and amount of extractives for all wood species except P fraxinifolia.
S M Kazemi
Combustion properties of Alder wood treated with some new environment friendly natural extractives. Part 1. Effect of Natural Tannins on the Combustion Properties
2002 - IRG/WP 02-40234
Powders of the brutia pine bark, sumach leaves, acorn, gall-nut and boric acid and borax which are known as potential environment friendly wood preservatives were impregnated according to ASTM D 1413-88 in order to determine their combustion properties. A commercial treatment compound, Tanalith-CBC, was also used for comparison. The results indicated that the natural extractives did not have any effect on combustion properties of alder wood and showed the same fire properties with control sample. However, when wood samples were treated with first natural extractives then boron compounds solution sequentially, the combustion properties were reduced.
Ü C Yildiz, A Temiz, E D Gezer, S Yildiz