Your search resulted in 31 documents. Displaying 25 entries per page.
The course of fixation of Cu-Cr-As wood preservatives
1972 - IRG/WP 307
Copper-chrome-arsenic (CCA) preservatives in contact with wood result in an instant extensive increase of pH, because of ion-exchange and adsorption reactions with the wood. During precipitation of the active elements the pH continuously increases but reaches a maximum, when all chrome is consumed. Some of the early reaction products are unstable and slowly convert via dissolution into stable comp...
S-E Dahlgren
Oxalate production and calcium oxalate accumulation by Gloeophyllum trabeum in buffered cultures
1994 - IRG/WP 94-10075
Most basidiomycetous fungi produce oxalic acid as a result of their metabolic activities and nutrient procurement. There is currently a renewed interest in the role that oxalic acid may play in the decomposition of wood by basidiomycete fungi. It has been observed that although most wood degrading fungi have the capacity to produce oxalic acid, not all of these organisms express this capacity equa...
J H Connolly, J Jellison
Selective chromate elimination from the storage-drainage-water of a wood impregnation plant
1980 - IRG/WP 3153
With the Enviro-Chrom-Ex process it is possible to eliminate ecologically and economically hexavalent chromium (chromate) from water selectively. The process which is based on the principle of selective ion exchange works with different chromate concentrations and under the presence of other ions, irrespective of the water hardness. The values of water-offtake reach 0.1 mg CrVI at maximum, causing...
O Wälchli, R Ott, R Hugener, E Graf, B Lieberherr
Some practical implications from recent research on the fixation of CCA preservatives
1975 - IRG/WP 358
The mechanism of fixation of CCA preservatives is briefly described. If the temperature is increased during the primary fixation period, the formation of intermediate fixation compounds is less extensive. The length of the primary fixation period is of practical interest. It is determined by preservative composition and concentration, temperature and wood species. Diagrams are given for Pinus sylv...
S-E Dahlgren
Rates of emission from CCA-treated wood in the marine environment: measurement, modelling and requirements for further research
2001 - IRG/WP 01-50166-12
Accurate estimates of rates of emission of leachate from preservative treated wood are crucial for realistic predictions of the environmental impact of its use in maritime construction. Estimates are available for some commonly used preservatives, but these vary widely. Though variable, these measurements suggest that emission generally decreases exponentially with time. Part of the variation is d...
S M Cragg, C J Brown, R A Albuquerque, R A Eaton
Detection of trace organics by ion mobility spectrometry
1990 - IRG/WP 3635
Ion Mobility Spectrometry (IMS) is a time of flight analytical technique that is suited to detect chemicals in the low parts per billion range. Some of the advantages of IMS are: operation at atmospheric pressure, fast response time (0.1-10 sec), and the ability to characterize individual chemical species in complex matrices without any prior sample preparation. In this paper, the utility of IMS i...
A H Lawrence
Detection of brown rot decay in wood by ion mobility spectrometry
1991 - IRG/WP 2377
A test method for the detection of brown rot decay in wood is described and involves a two-step procedure: thermal release of vapours from wood samples followed by analysis using Ion Mobility Spectrometry (IMS), with results being obtained in 5-10 seconds. The advantages, limitations as well as the detection limit of the technique are presented....
A H Lawrence, T Nilsson
Leaching tests - A paper for discussion
1973 - IRG/WP 221
J W W Morgan
Soil chemistry and wood decay
1978 - IRG/WP 2109
Soil is a most complex biological, chemical and physical material; its study is effectively a separate branch of science but almost entirely in relation to ist ability to grow plants - this paper is intendet just to note some known facets that might have relevance to the decay of wood and the performance of wood preservatives....
E A Hilditch
Determination of total fluoride in preservative-treated wood by ion selective electrode, without steam distillation
1996 - IRG/WP 96-20086
An analytical method was developed to determine total fluoride in wood treated with aqueous fluoride or borate-fluoride formulations. Ground wood was mixed with 60% sodium hydroxide solution and oven-dried overnight before furnacing at 600°C. The cool fused product was dissolved in warm water before adding a powerful complexant/buffer solution containing sulphosalicylic acid and EDTA. Fluoride wa...
M J Kennedy
An investigation into the influence of soil cation exchange capacity on preservative component depletion
1994 - IRG/WP 94-20050
The mobility of preservative components from treated wood into the soil environment is regarded as an important determinant of preservative performance. Standard procedures for the investigation of this phenomenon have not been developed to any great extent. Soil bed studies conducted in this laboratory using natural soil and modified soil media have provided interesting comparative data on the in...
K J Archer, L Jin
The foreign exchange situation and fate of wood preservation in Nigeria
1989 - IRG/WP 3558
Up to about 15 years ago, wood utilization industry in Nigeria gave no serious thoughts to wood preservation. After this period however, as a result of escalated local demand for sawn timber, logs with wider sapwood and mainly of secondary tree species requiring protection of the sawn timber became dominant in the local timber scene. Preservatives both for protection in and out of ground contacts ...
M A Odeyinde, S C Ifebueme
An evaluation of the potential of ion mobility spectrometry for detection of organic wood preservative components in solutions and treated wood
1994 - IRG/WP 94-20038
For the disposal of wood waste under ecological sound conditions information about its hazardous potential is required. Until now, no highly sensitive rapid analytical methods are available for the detection of wood preservatives under industrial process conditions. Preliminary experiments showed that Ion Mobility Spectrometry (IMS) could be a promising method for rapid detection of organic preser...
A Voss, J N R Ruddick, W J Homan, H Militz, H Willeitner
Determination of total fluoride and boron in preservative-treated wood fluoride by ion selective electrode without steam distillation, and boron colorimetrically using azornethine-h
1998 - IRG/WP 98-20135
An analytical method was developed to determine total fluoride and boron in wood treated with aqueous or solid diffusing fluoride or borate-fluoride formulations. Ground wood was mixed with 30% sodium hydroxide solution and oven-dried for 2 hours before furnacing at 600° C for 1 hour. The cool fused product was dissolved in hot water, transferred to a plastic beaker and neutralised. Fluoride was ...
P A Collins, M J Kennedy
The probable mechanism of action of boric acid and borates as wood preservatives
1990 - IRG/WP 1450
The tetrahydroxyborate ion [B(OH)4-] acts by complexation with poly-ols and probably attacks decay fungi through extracellular substrate sequestration; intracellular substrate sequestration; enzyme inhibition; and change in membrane function. Work was carried out to investigate this further and to try to explain certain phenomena observed in the area of boron preservation. The effect of Na borate ...
J D Lloyd, D J Dickinson, R J Murphy
The mechanism of leaching of copper-chrome-arsenic preservatives from treated timber in saline waters
1976 - IRG/WP 374
A mechanism for the leaching of copper-chrome-arsenic preservatives is proposed on the basis of theoretical calculations and experimental studies using timber subjected to a range of water types of different ionic compositions. Complex formation by copper (II) and chromium (III) with chloride and hydroxide ions is shown to affect the leaching rate. Of even greater importance is the salt effect on ...
J Irvine, S-E Dahlgren
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
Site characteristics impacting historic waterlogged wood: A review
2000 - IRG/WP 00-10344
Survival of waterlogged wood from hundreds and in rare cases millions of years presents scientists with a unique opportunity to examine wood specimens which, due to select properties of the wood itself and/or the depostional environment, have not been completely degraded. Although degradation patterns of various types of microbial wood decay have been studied in detail, the site parameters of the ...
B A Jordan, E L Schmidt
Diffusion and interaction of components of water-borne preservatives in the wood cell wall
1988 - IRG/WP 3474
This study investigates the rates of diffusion and ultimate distributions of copper and arsenate components of wood preservatives in wood cell walls following vacuum treatment. Adsorption studies of copper on red pine (Pinus resinosa) and trembling aspen (Populus tremuloides) wood confirm the importance of cation exchange reactions on the ultimate distribution of copper in the wood substance and i...
P A Cooper
Optimisation of an analytical method for the determination of total fluoride in preservative-contaminated soils using water steam distillation and an ion-selective electrode
1999 - IRG/WP 99-20153
This paper describes a simple modified procedure for the quantitative fluoride determination of different origin in a soil matrix using a water steam distillation and an ion-selective electrode. Distillation methods generally require a preliminary preparation step like fusing. The modified method presented here is based on the direct distillation of fluoride so that no further sample preparation i...
E Melcher
Assessing health risks to occupants following remedial insecticidal treatment of timber in dwellings
1998 - IRG/WP 98-50101-27
Experiments have been carried out to assess (i) the aerial concentrations of volatile wood preservative constituents, and (ii) the potential for contamination from treated surfaces, following in situ insecticidal treatment of timbers in dwellings. Using white spirit as a model for volatile constituents in the treatment of free-standing, wood-lined chambers indicated that temperature and air exchan...
R J Orsler, E D Suttie, V Rijckaert
Time-of-Flight Secondary Ion Mass Spectrometry Analysis of Polyethylene Glycol Penetration into Wood Cell Walls
2006 - IRG/WP 06-20328
Penetration of high molecular weight polyethylene glycol (PEG) into wood cell walls was investigated in red pine. PEG of different molecular weights (1000, 8000 and 20000) was labelled by bromination and treated samples were analyzed on Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) in dynamic mode. Both negative and positive spectra of the samples were collected in high spatial (bunche...
D Jeremic, P Cooper, P Brodersen
Micronized Copper Preservative Systems: Observations on the Release of Cupric ion (Cu2+) from Treated Wood and Performance against Wood Decay Fungi
2009 - IRG/WP 09-30519
In an attempt to address the mechanism of action of micronized copper preservatives, a 20-week continuous water leaching study was conducted. The leaching results indicated that, once impregnated in wood, micronized copper preservatives continuously release cupric ion, and the levels of cupric ion released from micronized copper treated wood are higher than those released from CCA treated wood, a...
J Zhang, R Ziobro
Adsorption of ACQ components in wood
2010 - IRG/WP 10-30522
To investigate the chemical adsorption capacity of copper-monoethanolamine (Cu-Mea) components on wood, the Na+ cation exchange capacity (CEC) of red pine (Pinus resinosa Ait.) was determined and compared to the adsorption capacity of free Mea and Cu-Mea complexes. The CEC increased with increasing pH. Free Mea adsorption as a function of pH followed the sodium adsorption curve except at pH over 9...
Myung Jae Lee, P Cooper
Copper nanoparticles in southern pine wood treated with a micronised preservative: Can nanoparticles penetrate the cell walls of tracheids and ray parenchyma?
2010 - IRG/WP 10-30547
This study tests the hypothesis that copper nanoparticles can penetrate the cell walls of southern pine wood treated with a micronised preservative. We examined the nanodistribution of particles in tracheid and ray parenchyma cell walls using state-of-the-art HR (High Resolution)-TEM and HR-STEM (Scanning Transmission Electron Microscope)-EDX. These devices are capable of atomic-scale resolution. ...
H Matsunaga, Y Kataoka, M Kiguchi, P Evans