Your search resulted in 385 documents. Displaying 25 entries per page.
Natural decay resistance of some lesser known /used timber species from the forests of Tanzania
2005 - IRG/WP 05-10557
In order to manage the Tropical forest in a sustainable manner and increase the resource base for their wood industries, many Tropical African timber producing countries including Tanzania are promoting the many lesser known/used timbers in their forests as alternative sources of wood to the over-exploited primary timber species. Four lesser known/utilized timber species from the forests of Tanzan...
S A Amartey, P R Gillah, R C Ishengoma, J Gabriel, D H Kitojo
Whitewood - An external joinery timber?
1975 - IRG/WP 253
The timber used traditionally for softwood joinery in the UK is redwood (Pinus sylvestris). In the past its ready availability in the desired sizes and quality and its durability in service encouraged little competition. However, the past decade has seen some erosion of this position, particularly through the increased proportion of sapwood in redwood supplies. Since the sapwood is less durable th...
J W W Morgan
The use of lap-joints in natural durability testing: moisture content development during 36 months outside exposure trials
2000 - IRG/WP 00-20217
Lap-joint trials (following European Standard ENV 12037) were set up with 11 different softwood and hardwood species. The main aim was to evaluate the suitability of this test standard (developed for testing wood preservative effectiveness) for natural durability testing. The moisture development has been followed during a 36 months period. In this paper, the outcomes of different moisture content...
H Militz, C J Bloom
Ability of heartwood extractives to inhibit the growth of a bacterial symbiont of Teredo navalis
2000 - IRG/WP 00-10369
Shipworms are important destroyers of wood in the marine environment, and wood users have long sought methods for preventing or limiting their attack. While heavy -duty wood preservatives are highly effective against these organisms, there is increasing concern about risks to non-target organisms. This has resulted in a gradual shift away from broadly toxic materials to either alternative material...
C S Love, A R Sipe, S C Cary, J J Morrell
Biocidal property of the phenolic fraction of ethanol extractives of Hopea parviflora heartwood
1993 - IRG/WP 93-30003
Natural resistance of some species of timber to fungal decay and insect damage (particularly termite) is ascribed toxic nature and quantity of certain chemical substances present in the cell wall of heartwood. These chemical substances generally known to be Phenolic and Polyphenolic compounds (Rao 1982). Earlier investigations on extractives were mainly in relation to resistance of timber to decay...
R V Krishnan, K S Theagarajan, H S Ananthapadmanabha, M Nagaraja Sharma, V V Prabhu, H C Nagaveni
Preliminary indications of the natural durability of Spruce bark board
1999 - IRG/WP 99-10312
A board material made from pressed bark, with no added adhesive, has been developed by Forintek's composites group and tested for durability by Forintek's treated-wood group and the University of Hawaii. This material was also manufactured with veneers in a one-step process. Since one role of bark on the tree is protection against pests and diseases, barkboard was expected to hav...
P I Morris, J K Grace, G E Troughton
The critical timing of inspections for field testing of natural durability
1994 - IRG/WP 94-20018
An overestimation of performance will almost always result if the condition of a specimen is considered to be attained at the precise time that an inspection is carried out. The time at which the condition is actually attained, referred to in this document as the "Condition time", is best considered to be halfway between two successive inspections. The requirement to obtain data that is relevant t...
J D Thornton
Assessment of untreated Papua New Guinean timbers against subterranean termites. Progress Report 1
1990 - IRG/WP 1436
Eight major commercial timber species (Intsia palembanica, Pometia pinnata, Homalium foetidum, Dracontomelon dao, Calophyllum spp., Eucalyptus deglupta, Nothofagus spp., and Alstonia scholaris) were exposed in ground contact against termites. Five replicates of heartwood stakes of 25x25x250 mm³ of each species were randomly embedded in the soil. Results after 24 months exposure showed that Kwila ...
M Rokova, H C Konabe
Susceptibility of heartwood of three Pinus species to attack by the subterranean termite Coptotermes acinaciformis (Froggatt)
1994 - IRG/WP 94-20026
Heartwood of plantation-grown Pinus elliottii (slash pine), Pinus caribaea (Caribbean pine) and Pinus radiata (radiata pine) was obtained from a range of locations throughout Australia and New Zealand for use in a field bioassey with subterranean termites. Timber stock was analysed for a number of stilbene and flavonoid heartwood extractive components which could contribute to variation in suscept...
M J Kennedy, L L Dixon, B C Peters
Comparative study on the leaching of wood preservatives between natural exposure and accelerating laboratory conditions
1999 - IRG/WP 99-50134
Impregnated specimens with CCA, ACQ, and BAAC were subjected to leaching tests. Specimens of 2x2x1 cm3 in size were used for the laboratory leaching test for 10 days according to JIS K 1571. Specimens of 25x1 x1 cm3 were used for outdoor leaching test for 6 months. Total leaching amounts of boron per cm3 of specimens treated with BAAC were 325 µg in the laboratory test and 206 µg in the outdoor ...
K Yamamoto, S Motegi, A Inai
Evaluation of extractives from African Padauk (Pterocarpus soyauxii Taub.) for protection of non decay resistant species
2002 - IRG/WP 02-10419
The development of a wood preservative made up of natural extracts is a potentially attractive prospect for the wood preservation industry. In this study, organic solvents were used to remove extractives from African padauk wood samples. The solvent was removed by rotoevaporation, and the total content of the viscous extracts determined to be 54.4mg/ml.
The toxicity of various extracts concentrat...
P Nzokou, D P Kamdem
Natural durability of tamarack (Larix laricina (Du Roi) K. Koch)
1998 - IRG/WP 98-10277
Eastern larch or tamarack (Larix laricina (Du Roi) K. Koch) lumber from New Brunswick, Canada was evaluated for heartwood natural durability according to ASTM D2017-81. The natural durability of tamarack heartwood exposed to two brown rot fungi, Gloeophyllum trabeum and Postia placenta was low and generally inferior to that of the heartwood of spruce (Picea sp.) and white pine (Pinus strobus L.) a...
U Srinivasan, A Taylor, P A Cooper
A questionnaire survey to establish the perceptions of UK specifiers concerning the key material attributes of timer for use in marine and fresh water engineering
2004 - IRG/WP 04-10519
Engineers have a key role in making informed decisions on the type of materials to be used in the schemes they design and construct. Currently, in England and Wales, it is believed that some £500m per year is invested in flood and coastal defence engineering. There is a lack of centralised data in the UK holding information on timber for usage in fluvial and, particularly coastal engineering. A...
J R Williams, G S Sawyer, S M Cragg, J Simm
On the changes of natural durability of wood sterilised by gamma radiation
2006 - IRG/WP 06-10571
The preliminary study data of natural durability of wood in lab conditions against rot fungi dependency on different sterilisation method have been presented. In the research, white rot fungus Schizophyllum commune Fr.: Fr. and brown rot fungus Poria placenta (Fries) Coke sensu J. Erikson. on the Scots pine were tested. Cobalt 60Co was used as a gamma radiation source at the dosage of 30 kGy. Cont...
R Despot, M Hasan, M Glavaš, G Rep
Comparative studies of natural durability of Japanese cedar (Cryptomeria japonica D. Don) among the geographic cultivates
2006 - IRG/WP 06-10592
Variation of natural durability of Japanese cedar (Cryptomeria japonica D. Don) (also known as Sugi) was investigated by accelerated tests for decay (Fomitopsis palustris (Berk. et Curt.) Murr.) and termite (Reticulitermes speratus Kolbe) attacks on 13 clones of Sugi trees from Kyushu-Okinawa Region (Fukuka, Ooita, Saga, Miyazaki, Kagoshima). For this purpose, 57 twenty-five years old Sugi trees o...
I Usta, K Takata, S Doi
The natural durability of wood in different use classes - PART II
2006 - IRG/WP 06-10598
The natural durability of important European wood species has been tested on 3970 speci¬mens in field trials. The wood was exposed at five test sites in Germany with different climates, at each site in European use class 4 and 3 (with and without soil contact). Within European use class 3 three different expositions were tested: vertical with sheltered end grain, vertical unsheltered and horizont...
A O Rapp, U Augusta, K Brandt
Protection of hard and softwood through Neem leaves extracts and oil - A direction towards development of eco-friendly wood preservatives
2006 - IRG/WP 06-30394
Conventional wood preservatives like CCA and CCB are facing lot of criticism all over the world. It is essential to address the problem in view of environment protection. Eco-friendly wood preservatives may be considered as one option. The present study is an expolartion of neem leaves and seed oil against wood decaying fungi and termites. Azadirachta indica A. Juss, commonly known as neem is one ...
S Dhyani, S Tripathi
The Influence of Extractives on Western Redcedar’s Equilibrium Moisture Content
2006 - IRG/WP 06-40331
The high natural durability of western redcedar (Thuja plicata Donn) heartwood is often attributed to the presence of the thujaplicins, which are toxic to fungi. However, sound, twenty-five year old western redcedar shakes and shingles were found to contain only traces of the thujaplicins, but significant quantities of plicatic acid (which is only weakly toxic to fungi). This suggests that factors...
R Stirling, P I Morris
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
The characteristics of biodegradation mechanism of gamma-irradiated wood
2007 - IRG/WP 07-20352
Gamma radiation, as an easy, fast and effective sterilisation method, changes molecular structure in pest’s living cells, but also in wooden cell walls. Radiation-induced depolymerisation causes significant changes in wood properties crucial for laboratory testing of wood-preservative effectiveness. Natural durability of wood against rot fungi in lab conditions dependency on different sterilisat...
R Despot, M Hasan, F Pohleven, M Humar, G Rep
Methods for Determining the Role of Extractives in the Natural Durability of Western Redcedar Heartwood
2007 - IRG/WP 07-20356
The durability of western redcedar heartwood is influenced by a number of different extractives operating by different mechanisms. In order to guide a systematic isolation of extractives with high fungal toxicity, a micro-bioassay has been developed for measuring the fungal toxicity of extractive fractions. Two additional assays quantify the anti-radical and metal chelating properties of cedar ext...
R Stirling, C R Daniels, J E Clark, P I Morris
Study of natural durability of Spanish Eucalyptus globulus wood
2007 - IRG/WP 07-10617
In some countries such as Australia, the wood of Eucalyptus globulus is recommended, due to its high durability, in risk situations where attack by organisms is likely to occur. In Galicia this species has been used for many decades for timber structures, which are still used. However, European Standard EN-350-2 places Eucalyptus globulus in the worst category of natural durability, a situation th...
D Lorenzo, M T Troya, M J Prieto, C Baso, M Touza
Potentiality of use extracts from Tetraclinis articulata like biocide against wood destroying organisms: Reticulitermes santonensis
2007 - IRG/WP 07-30418
Screening trials were conducted to determine the antitermitic and antifungal properties of essential oil and methanolic extractives obtained from Tetraclinis articulata heartwood. Extract-treated cellulose pads were used to evaluate antitermitic activity and complete termite mortality was obtained with the essential oil: the threshold is situated under 5% (v/v). Standardised tests according Europe...
F El hanbali, N Amusant, F Mellouki, M Akssira, C Baudasse
Theory of Aesthetics – Charm in Furniture and an Aesthetic Evaluation of Bleaching of the Natural Color of Wood through the Application of Experimental Bleaching Process
2007 - IRG/WP 07-30424
This paper consists of mainly three sections: In the first section, brief information is given on the theory of aesthetics as a branch of philosophy, historical progress of the aesthetics theory is summarized within the context of the term “beautiful”, and aesthetic values as well as the color and aesthetic effects of color in preparing the designs are explained. In the second section, relatio...
I Usta
Antifungal activity of plant derived extracts against G. trabeum
2007 - IRG/WP 07-30433
While synthetic chemicals have provided excellent protection to woods used in adverse environments, the general public remains interested in naturally derived wood protectants. There are diverse arrays of possible candidates, but many of these compounds are not readily water soluble and efforts to render them soluble often reduce biological activity. In this report, we describe efforts to enhance ...
M Maoz, I Weitz, M Blumenfeld, C Freitag, J J Morrell