Your search resulted in 6688 documents. Displaying 25 entries per page.
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
Wood preservation in Nigeria - Its increasing relevance, observed constraints and potential as a forest conservation option
1992 - IRG/WP 92-3732
The paper discusses the demand and supply of wood and wood products in Nigeria and points out that in view of the large population (88 million) and search for wood for housing and furniture, the demand exceeds supply. There is great shortage of industrial and domestic woods resulting in underutilization of installed machineries in forest industries and low profit margin. Under this prevailing cond...
M A Odeyinde, S C Ifebueme
Comparative study of lignocellulolytic activities of Pleurotus spp. and white rot and brown-rot fungi
1997 - IRG/WP 97-10209
Field and fungal cellar trials have been set up to assess the biocontrol potential of a selected Trichoderma viride isolate in a situation representative of the end use of treated timber in ground contact situations. These trials are designed to give information about the efficacy of biological control as well as the suitability of existing chemical treatment methods for use with biocontrol fungi....
H L Brown, A Bruce
Effects of hard water, sea water and humic acid on the release of CCA components from treated wood
2005 - IRG/WP 05-50228
Leaching medium is an important factor affecting release of preservative components from treated wood because physical and chemical characteristics of medium increase or decrease the solubility of fixed preservative components. This study evaluated the leaching properties of copper, chromium and arsenic elements from chromated copper arsenate (CCA)-treated wood specimens subjected to laboratory le...
S N Kartal, W J Hwang, Y Imamura
Acoustic technique for assessing decay in preservative treated wood
1998 - IRG/WP 98-20138
This study investigated the suitability of vibration techniques to assess the performance of wood preservatives in ground contact. Small stakes (10 x 5 x 100 mm3) of treated and untreated Scots pine sapwood were exposed to decay in lab-scale terrestrial ecosystems. Tests were conducted using three different soils including a garden compost soil, and soils obtained from a test field and a conifer f...
L Machek, M-L Edlund, R Sierra-Alvarez, H Millitz
Inhibition of the biodegradation of coniferous and broadleaved wood by new imidazolium salts
2003 - IRG/WP 03-30320
Studies were carried out on fungicidal values of fourteen potential wood preservatives – modified quaternary heteroaromatic compounds using the screening agar-block. The vacuum treated blocks (22mm x 17mm x 12mm) of Scots pine (Pinus sylvestris L.), spruce (Picea excelsa L.), beech (Fagus silvatica L.) and birch (Betula verrucosa Ehrh.) with testing compounds were exposed to Coniophota puteana a...
J Zabielska-Matejuk, J Pernak, W Wieczorek
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
Influence of the nature of the substrate and the method of inoculation on the degradative activity of soft rot fungi
1998 - IRG/WP 98-20133
The European Standard (ENV-807) determines the threshold of effectiveness of wood preservatives against the action of soft rot Ascomycetes fungi. Its application in the treatment of wood used in the hazard class 4 does not always offer repeatable results, which could be expected in an experimental norm.
For this reason, in this paper, we have evaluated the diverse variables that might influence t...
M T De Troya, A M Navarrete, F Rubio, J Jiménez, D Muñoz-Mingarro, C Rodríguez-Borrajo, F Llinares, M Yuste
The resistance of wood coated with different water-borne paints against colonisation by decay fungi
1996 - IRG/WP 96-10165
The susceptibility of wood painted with model paints of known composition to decay fungi was tested without previous weathering. Included in the study were five alkyd emulsion paints and five acrylic paints; one linseed oil paint and two solvent-borne alkyd paints. It was found that several components influenced the susceptibility of these paints. The results of the present study indicate that the...
J Bjurman
Research activities on marine wood biodeterioration in Indian waters
1992 - IRG/WP 92-4182
India has a sea coast of about 8,000 km - taking into account all islands in Arabian sea and Bay of Bengal. Considerable quantity of wood is used for jetties, piles, catamarans, coastal and fishing vessels etc. and expenditure made on all these strutures including losses involved due to damage by marine borers is considerable. Continous and rapid depletion of timber from our forests particulary at...
V V Srinivasan
Effects of the delay in the beginning of treatment on absorption and distribution of water-soluble salts in posts treated by sap-replacement method
1992 - IRG/WP 92-3719
One of the most important matters in green wood treatments, such as sap-replacement method, is knowing the longest time available for beginning treatment without losing efficacy. In this paper, the influence of this factor on absorptions and distribution of the preservative into the wood is analized. Tree start-up times were first chosen: 3-6 hours, 48 h and 120 h after being cut down. The treatme...
M V Baonza Merino
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
A field evaluation of chromated fluoride as a remedial treatment for creosoted wooden distribution poles
1989 - IRG/WP 3556
A commercial chromated fluoride formulation was applied by injection process to previously inoculated creosoted wooden distribution pole sections at a field site in Scotland and appraisal of the efficacy of the formulation against Lentinus lepideus was undertaken at two month and fifteen month intervals. Preliminary results suggest a rapid elimination of organisms from colonised areas. The usage o...
B King, A Bruce
Changes in transverse wood permeability during the drying of rimu and radiata pine
1990 - IRG/WP 3636
When softwoods are dried and subsequently impregnated with waterborne preservatives two problems frequently occur, preservative screening of multi-salt preservatives and difficult re-drying. To study the causes, the permeability of rimu and radiata pine wood has been measured along the three principal directions. The radial and tangential permeabilities of the green sapwood of the two species were...
R E Booker
Silica treatments to protect timber from marine borers
2001 - IRG/WP 01-30270
Siliceous timbers such as turpentine (Syncarpia glomulifera) are highly resistant to certain marine borers. Attempts to mimic this resistance by chemical treatment however, have met with limited success. This paper describes the impregnation of Pinus radiata and eucalypt timber specimens with organo-silicate formulations. The treated timber gains a pattern of resistance to marine borers that appro...
D Scown, L J Cookson, K J McCarthy
Diffusion treatment of gauged radiata pine timber using "Boracol 20"
1987 - IRG/WP 3437
Green gauged 100 x 50 mm radiata pine timber was preservative treated by brush application of "Boracol 20" followed by diffusion storage. Preservative retention analyses indicated that retention requirements in the core could be achieved within a six week diffusion period, thus representing a time saving of 25% over conventional boron treatment of rough-sawn radiata pine. Similar treatment of kiln...
D R Page, P Vinden, S Retter
New method to find out the volatile organic compounds (VOC) of wooden material
2000 - IRG/WP 00-20189
Volatile organic compounds (VOC) of pine, spruce and larch wood were studied using a new technique developed at VTT Chemical Technology. 50 mg of crushed wood material was placed into glass tubes. The tubes were closed with a glass wool, which is pressed with a tube cap. Wood samples were analysed with a gas chromatograph after thermal desorption using four different temperatures (50°C, 100°C, 1...
H Viitanen, K Villberg, K Saarela
Environmental impact of PCP and NaPCP in the aquatic and atmospheric compartment
1995 - IRG/WP 95-50040-06
PCP and NaPCP were studied for their aquatic toxicity on bacteria, microalgae and daphnids and for their behaviour in the atmospheric compartment with a climatic chamber. Results of aquatic toxicity bioassays showed that toxicity was higher at low pH. This can be explained by the pKa value of 4.7 of PCP and the higher concentration of the non dissociated form of the pesticide at more acidic pH. Vo...
P Marchal, P Vasseur, G Ozanne
Implications for comparability of laboratory experiments revealed in studies on the effects of population density on the vigour in groups of Coptotermes lacteus (Froggatt) and Nasutitermes exitiosus(Hill) (Isoptera: Rhinotermitidae, Termitidae)
1983 - IRG/WP 1197
(Summary of paper 1194)
The vigour - survival and wood consumption - of groups of Coptotermes lacteus and Nasutitermes exitiosus was measured when termites were kept at different population densities (g termites/ mL) by changing group size and/or volume of the holding container. A characteristic pattern emerged. At low population densities (< 0,01 g/mL) performance of termites improved with an increase in group size; at higher population densities it tended to decline. The impact of altering group size and container volume on termite vigour was most pronounced at low densities; at higher population densities, performance tended to be more stable but declined markedly when termites became overcrowded. In most jar-type experiments on termites, especially those conducted in Europe and the U.S.A., small groups of termites are housed in disproportionately large jars, resulting in very low, sub-optimal population densities. Suggestions are made for improvements in experimental design that would lead to an enhancement of the comparability of results from different laboratories.
M Lenz, R A Barrett, E R Williams
Partial seasoning and preservative treatment systems for pine roundwood
1982 - IRG/WP 3187
Experimental trials at FRI, Rotorua showed that the steaming schedule normally used for steaming and venting is also suitable for steaming and vacuum seasoning. Applying vacuum of up to -84 kPa immediately after steaming did not increase the initial loss of wood moisture significantly in comparison to steam/venting. The main improvement to wood condition by using steam/vacuum appeared to be to dis...
A J Bergervoet
Shockwaves in wood preservation
2005 - IRG/WP 05-40308
Shockwaves are strong perturbations in aerodynamics that propagate at supersonic speeds independent of the wave amplitude. Physically the occurrence of shockwave is always characterized in a fluid flow by instantaneous changes in pressure, velocity and temperature. In this paper we describe a new wood preservative injection system that has been developed utilizing the non-linear pressure spike beh...
G Jagadeesh, R Lal, G Ravikumar, K S Rao
A comparison of shower test results from CCF, CCZF, CCB and Cu-quat treated timber
1995 - IRG/WP 95-50054
The shower test quantifies the amount of specific preservative components which leach from treated timber under simulated open storage conditions. The test method measures leaching from both organic and inorganic salt treated timber. Shower tests of CCF, CCZF, CCB and Cu-quat treated timber which have been performed over the last 5 years by TNO are reviewed and compared. Leached components are qua...
M J Boonstra, A J Pendlebury, P Esser
Biological control in termite management – the potential of nematodes and fungal pathogens
2004 - IRG/WP 04-10521
A brief overview on the options for biological control of termites is presented. Many organisms have been identified as being able to kill termites, however, we do not know their real impact on field populations of termites. Most research has focused on some entomopathogenic nematodes and the fungi Beauveria bassiana and Metarhizium anisopliae. To date, only a limited number of field studies have ...
M Lenz
Pyrethroids: Isomerism and efficacy
1986 - IRG/WP 1284
Pyrethroids are drawing increasing attention to the wood preservative formulators because: ( 3; 6)
a) pyrethroids reveal good efficacy against a large variety of wood boring insects by contact.
b) pyrethroids show good long term efficacy because of their high stability in timber.
c) mammal toxicity is relatively low ( e.g. bats) (9).
d) pyrethroids are almost odorless.
It was found that diffe...
R Gruening, R Pospischil, S Cymorek, W Metzner
Diazenes and some organic complexes of boron as potential fungicides for preservation of wood
1999 - IRG/WP 99-30197
Screening for fungicidal activity represents the first step in searching for new active components with enhanced environmental profile in comparison with traditional wood preservatives. Diazenes, their salts, and the salts of the corresponding semicarbazides, as well as several complexes of boron, were screened for fungicidal activity against wood decay fungi Trametes versicolor, Coniophora putean...
M Petric, B Paradiz, J Stern, F Pohleven, S Polanc, B Stefane, R Lenarsic