Your search resulted in 138 documents. Displaying 25 entries per page.
The influence of the location of a wood defect on the modulus of elasticity determination in wood durability testing
2004 - IRG/WP 04-20287
This study investigates the influence of the location of a wood failure in stakes upon elastic changes observed in beech specimens with the resonance vibration technique. Natural failures were simulated by artificially created defects at different locations of the test stake. The results indicate that the location of an attack in a stake is important for the measurement outcome. When the attack is...
L Machek, H Militz
The degradation of wood by metal fastenings and fittings
1972 - IRG/WP 302
As well as the hazards of biological decay, timber used in boat building is subject to the effects of chemical decay associated with the corrosion of metallic fastenings. The title has been deliberately chosen to emphasize that in wooden construction the troubles are not just those of corrosion of the fastenings, but also the destructive secondary effects on the wood caused by the products of the ...
L C Pinion
A comparison between different accelerated test methods for the determination of the natural durability of wood
1996 - IRG/WP 96-20099
According to the European standard EN 350-1 the natural durability of wood is defined as: "the inherent resistance of wood to attack by wood destroying organisms". This standard also describes how, for certain hazard classes, the durability is determined. The two methods described in this standard are the kolleflask method (EN 113) and the field-stake-test method (EN 252). The EN 113 test gives re...
H Militz, S G L Michon, J E Polman, M Stevens
The use of spruce for transmission poles
1973 - IRG/WP 326
A series of preservative treatments with creosote using Lowry and Rueping schedules was undertaken. From these treatments the most suitable impregnation conditions for water stored Sitka spruce (Picea sitchensis) and Norway spruce (Picea abies) transmission poles were determined. Preservative distribution and permeability values for poles of both species were used to decide the optimum season and ...
J A Dunleavy, D J Balfe, J P Prendergast
Water-storage for improving the permeability of sugi (Cryptomeria japonica D. Don)wood
1999 - IRG/WP 99-40129
The viable bacterial counts in sapwood and intermediate wood of sugi bolts increased immediately after floated in a fresh water pond. Bacterial invasion into the heartwood was not detected apparently during water-storage for 36 weeks, although a few bacterial species have inhabited in freshly-cut heartwood samples. The bacterial species isolated from the water-stored bolts were almost Gramnegative...
S Ohta, S Doi
Studies on the permeability of Norway spruce (Picea abies)
1987 - IRG/WP 2295
It is well known that the bordered pits play a dominating role for liquid transport in softwoods. The mechanism behind pit aspiration during drying or heartwood formation seems to be well understood. The reason why the fixation of the membrane (torus) to the pit opening remains almost irreversible is, however, still unclear. A technique has been developed combining so-called "solvent exchange dryi...
I Johansson, K Nordman-Edberg
Field and greenhouse testing of window joinery of pine and spruce treated with LOSP
1991 - IRG/WP 3658
Norwegian window frame components of full size were double vacuum-treated with TBTN and TBTO, and connected as 'L-joints' and subsequently coated with stains. The corner sections were exposed (out of ground contact) both in field (temperated coastal climate, Taastrup, Denmark) and in a greenhouse (Uppsala, Sweden). The window frame L-joints of spruce (Picea abies Karst.) - treate...
F G Evans, B Henningsson, E Borsholt
Leachability of didecyldimethylammonium chloride (a quaternary ammonium compound) from four wood species
1982 - IRG/WP 3204
Sapwood blocks prepared from red pine, ponderosa pine, southern yellow pine and hem-fir (a commercial mixture of western hemlock and amabilis fir) were treated with didecyldimethylammonium chloride, (an alkylammonium compound, AAC). After oven drying the blocks were vacuum impregnated with distilled water and subjected to a static leach cycle for 48 hours. The leachate was analyzed and the amount ...
J N R Ruddick, A R H Sam
Determination of chlorine-containing wood preservatives in art objects using Micro-XRF
2003 - IRG/WP 03-20266
The applicability of a mobile energy-dispersive micro X-ray fluorescence (μ-XRF) spectro-meter for the analysis of organochlorine-containing wood preservatives in art objects was tested. Information about the relative degree of contamination and the efficacy of detoxification measures with emulsive solvent systems can be gained using the intensity of the chlorine signals. μ-XRF t...
J Bartoll, A Unger, S Krug, K Püschner, H Bronk
The effect of water storage on the cell-structure of Sitka spruce (Picea sitchensis) with reference to its permeability and preservation
1970 - IRG/WP III 3A
Commercial treatment trials with full sized transmission poles have shown that water storage considerably improves the permeability of Sitka and Norway spruce. These results were confirmed by laboratory measurements which showed that in the sapwood of ponded Sitka spruce there is a vast improvement in permeability in all three grain directions. Heartwood permeability does not seem to be affected t...
J A Dunleavy, A J McQuire
The quantitative determination of quaternary ammonium compounds in treated timber – results of an extended ring test
2002 - IRG/WP 02-20240
The determination of quaternary ammonium compounds (QAC) by means of a 2-phase-titration or photometry is a well established procedure for the quantification of cationic detergents in aqueous solutions. It is known that this analytical principle can also be used for the measurement of QAC extracted from treated timber. However only few information are available concerning the reproducibility or th...
E Melcher, C Bornkessel, J Gunschera, R Hamberg, H Härtner, H-N Marx, U Schoknecht, J Wittenzellner
Determination of N-cyclohexyl-diazeniumdioxide (HDO) containing compounds in treated wood using GC-MS
2000 - IRG/WP 00-20201
Beside the biological effectiveness the approval of a chemical wood preservative requires also techniques for the analytical determination of active ingredients in different matrices. Fulfilling of the last requirement is particularly difficult in the case of impregnated timber treated with wood preservatives containing organic compounds. This paper describes a procedure for the determination of t...
P Jüngel, J Wittenzellner, E Melcher
Determination of boron levels in solution and in treated wood
1994 - IRG/WP 94-20041
Four methods of measuring boron levels in solutions were investigated. The methods compared included the azomethine-H method which is commonly used in soils and plant tissues, the methods outlined in the Australian Standard AS 1605 (1974) and in Wilson (1958), and the atomic absorption spectrophotometry method. Defect-free radiata pine (Pinus radiata D. Don) sapwood and wood flakes were treated to...
F J Romero, P Vinden, P Kho
Determination methods of phytotoxic effect of wood preservatives
1990 - IRG/WP 2349
The phytotoxic effect of wood preservatives so widely used plays a considerable role in the protection of natural environment. A review was made of the existing methods with which to assess the phytotoxicity of the above chemicals and some suggestions were given concerning the methods most appropriate for their unification. Two areas of research are proposed: 1) estimating the direct effect on ind...
A Kundzewicz, J Wazny
Co-operative research project on L-joint testing. Sampling after 18 months exposure
1984 - IRG/WP 2233
In September 1983, Document No: IRG/WP/2208 was distributed giving guidance on sampling after 8 months exposure (due 1 December 1983 for those L-joints exposed on schedule on 1 April 1983), and including tables on which to record the test results. No major problems have been notified to Princes Risborough Laboratory concerning the sampling method. It is therefore proposed that the next sampling, a...
J K Carey, A F Bravery
A comparison between high and conventional incision densities for improving preservative treatment of Douglas-fir heartwood lumber
1993 - IRG/WP 93-40009
Incising is required for the preservative treatment of most wood species from the western United States; however, there is considerable debate about the density of incisions required to achieve adequate treatment. Previous studies have shown that the incision effect on treatment is relatively narrow, suggesting that incision densities should be significantly increased over current practices and st...
S T Lebow, J J Morrell
Co-operative research project on L-joint testing. Progress report to March 1986
1986 - IRG/WP 2272
Further sets of data received from CTFT (France) after 18 months exposure, BAM (Germany) after 18 months exposure, STU (Sweden) after 9.5 months exposure and TI (Denmark) after 12 and 17.5 months exposure are presented and discussed in conjunction with data previously reported. The new data are generally in agreement with those presented previously and indicate the major difference between the co-...
J K Carey, A F Bravery
Microwave digestion of preserved wood for the determination of Cu, Cr, As, B and P in quality control
1991 - IRG/WP 2364
A microwave digestion method for the determination of copper, chromium, arsenic, boron and phosphorus in preserved woods is described. Samples were digested with nitric acid in pressure-relief type teflon PFA vessels by microwave heating in a commercial laboratory microwave oven. Fast, efficient and complete digestion was achieved within 29 min for 12 samples. The digestion time compared favourabl...
N Bernth, L B Sheard
Improved preservative penetration of spruce after pre-treatment with selected fungi. II. Creosote treatment, analysis and strength testing
1998 - IRG/WP 98-40106
This paper describes the creosote treatment and analysis of logs pre-treated with selected fungal agents as a method of increasing the porosity of the wood prior to preservative treatment. The paper also reports the subsequent strength testing of the timber to evaluate the effects of the fungal pre-treatment on the structural integrity of the wood.
European spruce logs were pre-treated with eithe...
E J Tucker, A Bruce, H J Staines, B Rosner, K Messner
Estimation of mycelial biomass by determination of the ergosterol content of wood decayed by Coniophora puteana and Fomes fomentarius
1989 - IRG/WP 1415
The mycelial biomass of fungi decomposing wood materials may be estimated by the use of an ergosterol assay technique.ln decay tests, essentially according to EN 113, estimates made by HPLC analyses on wood decayed by Coniophora puteana and Fomes fomentarius show the increase in biomass in the wood blocks. The ergosterol contents were correlated with dry weight loss determinations. Degradation of ...
K Nilsson, J Bjurman
Microwave modification of wood properties - Improvements in wood permeability
2000 - IRG/WP 00-40181
A new method of microwave (MW) wood modification is described. Microwave irradiation of timber provides an improvement in wood permeability mainly in the radial and longitudinal directions. This is achieved by physically modifying ray cells and forming a large number of cavities in the radial - longitudinal planes. More extensive MW irradiation of different species transforms the wood into a new m...
G Torgovnikov, P Vinden
Determination of the amine to copper ratio remaining in wood after leaching
2002 - IRG/WP 02-30285
The effectiveness of the protection and the environmental impact of the treated wood are two of the most important aspects that need to be understood for all preservatives. Both are particularly influenced by the loss of biocidal components from treated wood. For amine copper preservatives, copper fixation determines the leaching resistance of the copper and amine compounds formed in wood. Previou...
N Lucas, J N R Ruddick
Co-operative research project on L-joint testing. Progress report to March 1985
1985 - IRG/WP 2236
It was originally intended that each participant would expose L-joints in the main trial on 1 April 1983 with the first sampling at 8 months (1 December 1983) and the second sampling at 18 months (1 October 1984). In the event, some participants have had to vary this schedule. Results after the first sampling have been received from CTFT (8 months), BAM (12 months) and Sipad-IRC (8 months) and aft...
J K Carey, A F Bravery
Mercury porosimetric evaluation of the impregnability of wood
1985 - IRG/WP 2234
Mercury porosimetric measurements for specimens of a given length can not be used to evaluate the treatability of wood. The reason is that the permeability for low permeable woods deviates from Darcy's law with the specimen length. This paper presents a method of evaluation which respects this phenomenon in indicating not only pore size but also a factor describing the pore size as a func...
J P Hösli
Computerized axial tomography. A non-destructive method for three-dimensional wood density/moisture content measurement
1987 - IRG/WP 2285
Computerized Axial Tomography (CAT-scanning) - used for medical investigations of the brain - has been evaluated as a nondestructive method of three-dimensional wood density/moisture content measurements. Density can be measured with an accuracy of ±3 kg/m³, and the accuracy in average moisture content is ±1% below and above fibre saturation point. It is theoretically possible that measurements...
L O Lindgren