Your search resulted in 72 documents. Displaying 25 entries per page.
Properties of hot oil treated wood and the possible chemical reactions between wood and soybean oil during heat treatment
2005 - IRG/WP 05-40304
Thermal treatment with hot oil as the heating media based on the original idea from oil-heat treatment in Germany was investigated. The treatment was mainly carried out at 200ºC and 220ºC for 2 hours and 4 hours, and the wood species were mainly spruce and fir. This paper focuses on the difference between soybean oil and palm oil and the possible chemical reactions between wood and soybean oil. ...
Jieying Wang, P A Cooper
Estimation of oral toxicity of boron as a bait toxicant and the trophallactic effects between individual members of termite colonies.
2003 - IRG/WP 03-10495
In recent years, because of the favourable environmental characteristics of boron, researchers in the wood preservation industries have refocussed on the use of boron as a major wood preservative against wood-destroying insects. Currently the greatest use of boron compounds is in remedial treatments.
Boron has been found to have slow-acting toxicity against subterranean termites. Because of thi...
B M Ahmed
Factors affecting decay rates in a fungus cellar II
1986 - IRG/WP 2259
Tests were initiated to investigate the influence of various factors on the decay rate in a "Fungus Cellar". Birch and pine stakes treated with chromated copper arsenate and didecyldimethyl ammronium chloride, as well as untreated control stakes, were incubated in two soils in a Fungus Cellar test and installed at two field sites for comparative purposes. The visual rating vs actual stake weight l...
P A McKaig
Investigation of the suitability of silver fir (Abies alba Mill.) for thermal modification
2004 - IRG/WP 04-40275
In this study the suitability of silver fir (Abies alba Mill.) was examined for thermal modification. Comparative experimental investigations were performed with silver fir and Norway spruce (Picea abies Karst.) after thermal treatments. Besides properties, which characterize the quality of heat treatments, like dimensional stability and resistance against fungal attack, strength properties of the...
C Brischke, A O Rapp
The improvement of wood durability by retification process
1993 - IRG/WP 93-40015
A material with new properties is obtained by retification process. It consists of a light pyrolysis of wood which becomes more stable and especially more resistant to fungal attack with few decrease of mechanical properties. Tests were carried out on three susceptible wood species (Poplar, Spruce, Fir) that are used in construction and are difficult to treat with wood preservatives. Retified wood...
D Dirol, R Guyonnet
Interactions between water-borne preservatives and emulsion additives that influence the water repellency of wood
1991 - IRG/WP 2374
Incorporation of non-polar additives into water-borne treatments through of emulsion technology can greatly improve the physical characteristics of wood in service. Of specific interest with these emulsions is their effectiveness in reducing the rate of wood swelling. We have observed that the presence or absence of preservatives can often significantly influence the resultant effectiveness of the...
A R Zahora
Influences of the hydro-thermal treatment on physical properties of beech wood (Fagus orientalis)
2005 - IRG/WP 05-40303
Influences of the hydro-thermal treatment on physical properties of beech wood were studied. Wood specimens (2×2×2cm) were treated in two steps. At first step, samples were treated at 160,180 & 200ºC for 4, 5 & 6 hours. At second step, treated samples were cured based on their first step treatment temperatures (160,180 & 200ºC) for 16 hours. The treated samples were soaked in water...
B Mohebby, I Sanaei
Estimates of wood-consumption rates by termites
1983 - IRG/WP 1201
Effects of 2 components; termite-biomass and experiment duration on estimates of wood-consumption rates (mg wood/g termite/day), were examined. Three models; (1) no mortality, (2) linear mortality and (3) nonlinear mortality were used to calculate mean standing-crop biomass of termites. Model (1) predicted a significantly lower wood-consumption rate than those based on models (2) and (3). No signi...
N-Y Su, J P La Fage
Improvement in dimensional stability against water of the main Spanish timbers impregnated with water repellent organic protectors
1988 - IRG/WP 3468
The study reported the increase of dimensional stability against water of the main Spanish timbers, both broadleaved and coniferous, after impregnation in the autoclave with organic protector, with contains 33.3% water repellent waxes and resins. The proposed Spanish standard, U.N.E. n° 56541 is used, where dimensional stability of the impregnated wood is expressed as a% of that of the non-impreg...
J A Rodríguez Barreal
The natural history of teredinid molluscs and other marine wood borers in Papua New Guinea
1975 - IRG/WP 410
The teredinids, commonly known as teredos or shipworms, are bivalve molluscs adapted to boring into wood. They are most closely related to the Family Pholadidae, or piddocks, which bore into mud, stone and coral. The teredinids have a relatively small, hemi-spherically shaped shell, the elongated body extending beyond the posterior end of the shell valves. The soft body, protected by the wood and ...
S M Rayner
In vivo growth study on two gymnosperms and four angiosperms for REB wood poles
1998 - IRG/WP 98-10246
Revealed that the highest growth rates and pole yield in two plantation sites in Bangladesh are significant with 2.06 cm/y in diameter, 0.97 m/y in height and 90% pole yield within 19y in Pinus caribaea; 1.96 cm/y, 0.91 m/y and 100% pole yield within 15y in Xylia dolabriformis; 1.88 cm/y, 0.91 m/y and 22% pole yield within 13y in Dipterocarpus turbinatus; 1.64 cm/y, 0.82 m/y and 28.75% pole within...
A K Lahiry
Influence of water-borne preservatives on water repellency and the impact of addition of water repellent additives
1992 - IRG/WP 92-3704
The primary goal of a desirable wood preservative system is to effectively control decay fungi and other biodeteriogens in service. The water repellent nature of a given system may play an important role in the protection of wood. In this study, the water repellency of several water-borne preservative systems has been evaluated by measurements of tangential swelling during immersion. The systems i...
L Jin, D M Roberts, A F Preston
Factors affecting decay rates in a fungus cellar
1985 - IRG/WP 2242
Birch and pine stakes treated with chromated copper arsenate and didecyldimethylammonium chloride were incubated in two soils in a "Fungus Cellar" test. At three month intervals, sets of stakes were inspected and assigned visual ratings or removed from the soil beds for weight loss determination. Preliminary results after nine months exposure have shown differences in the decay rates between birch...
P A McKaig
A substantively bonded water repellent treatment based on chromium carboxylates
1985 - IRG/WP 3344
Chromium carboxylates soluble in toluene have been synthesised and applied to Scots pine (Pinus sylvestris) sapwood. Without any further treatment, the compounds may be readily leached from wood surfaces with toluene. After a period of heating however, they become fixed to the cell wall, substantial amounts being resistant to leaching even under reflux conditions for several hours. Treatment of wo...
J K Wright, W B Banks, W J Eilbeck
Decay rates and strength and stiffness loss in foundation beams
1992 - IRG/WP 92-1563
The TNO Centre for Timber Research has executed an extensive research programme into the rate of decay in foundation beams, as a result of lowering of ground water tables. The aim of the research was to develop a method, predicting the decrease in strength and stiffness in beams, due to wood decay during drytime of foundation beams. With the calculated extremes in decay, the damage caused by local...
P Esser, H S Buitenkamp
Comparing microbial colonisation and Decay Rates of Wood from Sound and Aphid-Killed Kenyan-Grown Mexican Cypress (Cupressus lusitanica)
2006 - IRG/WP 06-10599
Samples of wood from 10, 15, and 30-year old trees attacked and killed by the cypress aphid (Cinara cupressi) and sound Kenyan-grown Cupressus lusitanica trees were investigated for variations in moisture content, density and susceptibility to microbial decay. MC varied with tree age, a normal trend, and between samples from aphid-killed and sound trees. In samples from 10, 15 and 20-year old so...
R Venkatasamy
Heat treatment of less-valuable Nigerian-grown Ceiba pentandra wood for improved properties
2006 - IRG/WP 06-40332
The hardwood Ceiba pentandra locally known as “ araba “ in Nigeria is rarely used for structural and construction works due to its high dimensional instability, low strength and durability values. Samples (10 x 10 x 150mm) were removed from four green boards (25 x 200 x 3000mm) of this species originating from a natural forest stand in Nigeria and subjected to 2-hour heat treatment at 160°C a...
L Awoyemi
Hydrophobic characteristics of pyrolysis oil
2008 - IRG/WP 08-30458
Hydrophobic behavior of pyrolysis oils obtained by pyrolysis of Scots pine wood (Pinus sylvestris L.) by using extruder type pyrolyzer at 450, 550 and 600 ºC was the objective of the study. Sapwood specimens (15×25×50 mm along the grain) were impregnated with the obtained pyrolysis oils by full- and empty cell treatment.
The results indicated that wood impregnated with the studied pyrolysis o...
A Temiz, M Hakki Alma, N Terziev
A comparison of rates of decay and loss in stiffness of radiata pine and Douglas fir framing lumber
2008 - IRG/WP 08-20378
Stiffness loss with time was recorded for untreated radiata pine and Douglas fir framing size lumber and preservative treated radiata pine which dad been pre-inoculated with Oligoporus placenta, a brown rot decay fungus isolated from decaying untreated radiata pine framing. Between stiffness measurements, samples were contained in a plastic tank located outside at ambient temperature. Index of Con...
M Hedley, D Page, J van der Waals
The effect of gamma radiation on selected wood properties
2008 - IRG/WP 08-40394
As an easy, fast, and effective sterilisation method, gamma irradiation changes molecular structures not only in pest’s living cells, but also in wooden cell walls. Radiation-induced depolymerisation causes significant changes in some properties of wood crucial for restoration and for laboratory testing of wood-preservative effectiveness. The influence of gamma radiation concerning total amount ...
R Despot, M Hasan, A O Rapp, C Brischke, C R Welzbacher
Preliminary investigation of biological resistance, water absorption and swelling of thermally compressed pine wood panels
2008 - IRG/WP 08-40396
Wood can be modified by compressive, thermal and chemical treatments. Compression of wood under thermal conditions is resulted in densification of wood. This study evaluated decay and termite resistance of thermally compressed pine wood panels at either 5 or 7 MPa and at either 120 or 150?C for one hour. The process caused increases in density and decreases in thickness of the panels; however, lab...
Ö Ünsal, S N Kartal, Z Candan, R Arango, C A Clausen, F Green III
Thermal treatment of Nigerian-grown Albizzia zygia and Funtumia elastica wood in soy oil medium.
2008 - IRG/WP 08-40413
Thermal treatment in soy oil medium is one of the techniques used as a substitute to the chemical treatment in wood preservation. However, the effects of this technique vary from one species to another and hence the need to investigate the response of individual species to it. Thermal treatment of air-dried Nigerian-grown Albizzia zygia and Funtumia elastica wood was carried out in a vessel contai...
L Awoyemi
Emission Rates of Active Substances from Preserved Wood in Use Class 3
2008 - IRG/WP 08-50256
The evaluation of an active substance or a biocidal product under the Biocidal Products Directive (BPD) requires that an environmental risk assessment is carried out. The risk assessment for wood preservatives includes scenarios for preserved wood (e.g. cladding on a house), in which the
predicted environmental concentration (PEC) in soil is calculated, using an emission rate for the active subs...
E F Baines
Dimensional Stability of Nine Tropical Hardwoods from Cameroon
2009 - IRG/WP 09-10687
This study investigated the swelling behavior, rate of swelling and dimensional stability of nine tropical hardwood species from Cameroon, namely ayous (T. scleroxylon), bilinga (N. diderrichii), bubinga (G. tessmannii), iroko (C. excelsa), Makore (M. heckelii), moabi (B. toxisperma), movingui (D. benthamianus), teak (T. grandis) and zingana (M. brazzavillensis). Continuous swelling was monitored ...
S R Shukla, D P Kamdem
Evaluation of Water Repellency of Treated Wood Using Several Alternative Methods
2009 - IRG/WP 09-20419
In this study, the results of water repellency testing using a digital swellometer method for water-borne organic-preservative systems with water repellent additives are reported. The findings suggest that the traditional method of using matched untreated controls as a reference developed from historic solvent-based treatments for determination anti-swelling efficacy (ASE) may underestimate the a...
L Jin, A F Preston