Your search resulted in 171 documents. Displaying 25 entries per page.
Field test design for service life prediction of wooden components
2005 - IRG/WP 05-20308
Wood is predominantly degraded by organisms. Thus, compared to other building materials, service life of wooden material is influenced by many more factors, which are divided into direct and indirect factors. Climate, geographical position, and construction criteria count to the indirect decay factors.
Besides material inherent properties (natural durability, wood preservatives), wood temperature...
A O Rapp, C Brischke
An example of media response to perceived environmental problems with CCA-treated wood
1990 - IRG/WP 3564
A recent study suggested that CCA-treated wood exposed to acidic precipitation could lose significant amounts of copper chromium and arsenic resulting in loss of efficacy and possible environmental contamination. The study received wide newspaper and radio coverage in Canada, thereby heightening public concern about CCA use. Subsequent studies in our laboratory confirmed that the high losses were ...
P A Cooper
Temperature tolerance of Botryodiplodia theobromae causing sapstain on rubber wood
1998 - IRG/WP 98-10259
Botryodiplodia theobromae Pat. is the dominant fungus causing sapstain on tropical timbers. Rubber wood (Hevea brasiliensis) is highly susceptible to sapstain infection. The tropical warm-humid climate also influences the growth of B. theobromae on rubber wood. Additionally, the moisture content of timber provides conducive conditions for the entry and establishment of the fungus. Temperature tole...
E J M Florence, J K Sharma, R Gnanaharan
The relationship between the electrical resistance and fixation of water-borne CCA salts and pressure-treated wood
1991 - IRG/WP 3657
Two investigations at 22°C and 30°C have been carried out. The electrical resistance in the treated wood and chemical analyses of the remaining amount of unfixed copper, chromium and arsenic were investigated. Samples impregnated with water were used as references. To hold the samples moist during the investigation, each sample was wrapped in a polyethylene plastic foil immediately after impregn...
F G Evans, B Nossen
Models of the critical time of humidity and temperature conditions for the development of mould fungi in pine and spruce sapwood
1995 - IRG/WP 95-20066
Regression models of the time factor for the growth of mould fungi in pine and spruce sapwood are studied. The first group of models are based on the results of exposures of mould fungi in static humidity and temperature conditions indicating the time for the start of mould growth in wood. The second group of models are based on the exposures of mould fungi in fluctuating or alternating humidity a...
H Viitanen
Supercritical fluid impregnation of Douglas-fir heartwood with cyproconazole using temperature induced deposition
2003 - IRG/WP 03-40259
A limited understanding of the fundamental aspects of supercritical fluid (SCF) impregnation in wood remains an obstacle to the development of this technology. Developing a better understanding of the effects of various process parameters on treatment results would facilitate more rational development of SCF impregnation. In this project, the effect of treating period and specimen length on su...
Sung-Mo Kang, J J Morrell
Heat transfer and wood moisture effects in moderate temperature fixation of CCA treated wood
1994 - IRG/WP 94-40022
Practical aspects of heat transfer and fixation of wood exposed to drying conditions after CCA treatment are considered. The rates of heat transfer and CCA fixation are substantially influenced by the cooling effect of water evaporating from the wood surface when drying occurs during fixation. At least in the early stages of fixation, the wood temperature approaches the wet bulb temperature, rathe...
J Chen, M Kaldas, Y T Ung, P A Cooper
Methods of culturing Lyctidae
1980 - IRG/WP 1126
Members of the tropical countries in the IRG Sub-Group "Insects in dry wood" requested a paper on the breeding of lyctids. Compared with other wood boring insects, such as cerambycids and anobiids, the breeding of lyctids is not as difficult and time consuming. Nevertheless some basic principles have to be observed in the laboratory to obtain successful cu·ltures. It is the intention of this repo...
H Kühne
Temperature and pressure inside wood during creosote impregnation
1991 - IRG/WP 3649
Creosote gives the best protection against decay for sleepers and poles. However, it has a major drawback - bleeding. Modified impregnation processes to reduce bleeding have been tried. For developing such processes it is important to know the actual temperature and pressure inside the wood. This paper describes measurement of temperature and pressure inside wood during creosote impregnation. The ...
Ö Bergman
Effect of nutrient regimes, temperature, pH, and wood sterilization method on performance of selected bioprotectants against wood staining fungi
1992 - IRG/WP 92-1551
The effect of nutrient regimes, incubation temperature, media pH, and wood sterilization method on performance of four potential bioprotectants (Pseudomonas putida, Pseudomonas cepacia, Bacillus subtilis, and Trichoderma harzianum) against wood staining fungi were evaluated using small ponderosa pine samples over a four week period. Incubation at 32°C resulted in slight increases in the degree of...
J J Morrell, C M Secton
Wood kiln drying. Simple process of material treament or soft method of preservation? (Le séchage arificiel du bois. Simple opération de traitement du metériau ou méthode douce de préservation?)
1993 - IRG/WP 93-50001-14
Among the processes enabling to extend wood durability, kiln drying can be considered as a treatment and soft preservation method. Dry woods are naturally durable provided they are not subject to important retaking of the moisture. Drying thanks to the application of temperatures from 50 to120°C enable to execute a thermic treatment which kills grubs and mushrooms to ensure a sterilization that c...
F More-Chevalier
Clean creosote - its development, and comparison with conventional high temperature creosote
1983 - IRG/WP 3235
Pigment emulsified creosote (PEC) is presently being tested and shows considerable stability in terms of water content, pigment level, pH, viscosity, rheological behaviour and microscopy. Timber samples from several eucalypt species have been treated with PEC and side matched samples treated with conventional high temperature creosote (HTC). The PEC treated specimens showed higher weight retention...
C W Chin, J B Watkins, H Greaves
Effect of humidity fluctuations on mould growth on pine wood
1989 - IRG/WP 1412
Most studies on mould development on wood material have been made at constant moisture conditions during the experimental period. As a consequence of such studies, a maximum permittable humidity level to avoid mould problems in wood constructions has been recommended. In the practical situation, the constructions are seldom subject to constant humidity or temperature. In the present paper, we repo...
J Bjurman
Development of a disinfection treatment for oak logs to be imported from the USA
1984 - IRG/WP 3283
The European veneer industry depends greatly on oak supplies from the USA. To prevent the accidental introduction of the American Oak Wilt Disease (Ceratocystis fagacearum) into the member states of the EC, a disinfection treatment was developed for oak logs under consideration of the technical requirements of veneer production. Laboratory experiments and field trials in Germany and in the USA sho...
W Liese, M M Ruetze
Investigation of extracellular mucilaginous material in some wood decay fungi
1996 - IRG/WP 96-10188
The external morphology of the extracellular mucilagenous material (ECM) produced by Coriolus versicolor and Coniophora puteana during colonization of Scots pine and beech was studies using SEM. Specimens were examined in the frozen hydrated, freeze-dried and critical point dried state. All technics produced artefacts but the ECM was best preserved when examined the frozen hydated state. Critical ...
A R Abu, D J Dickinson, R J Murphy
Dutch national environmental policy strategy (NMP): Implications throughout the life cycle of treated timber and for the Dutch preservation industry
1993 - IRG/WP 93-50001-31
All overview of relevant environmental legislation and instruments for control is given for each stage of the life cycle of treated timber. Recent policy in the Netherlands has been focused around the "National Environmental Policy Strategy", in which a general policy with regard to reduction of pollution to the air, soil and water is described. The principle is one of an "Integrated Chain of Cont...
P Esser, D A Lewis, A J Pendlebury
Experiments on the degradation of tributyltin oxide: A progress report
1984 - IRG/WP 3287
A variety of experiments designed to assess the chemical and physical factors affecting the degradation of tributyltin oxide in treated timber are described. Simple procedures in which temperature and oxygen availability were increased in the presence of wood and water suggest that the wood itself was of prime importance. Attempts to decrease degradation with antioxidants were unsuccessful but led...
R J Orsler, G E Holland
Fixation of CCA preservatives in cocos-, oil- and rattan-palm
1986 - IRG/WP 3371
In previous tests with jubaea-palm almost no fixation of a CCA-preservative Type B could be achieved, consequently, further leaching tests were carried out with samples of 1 cocos-, 1 oil- and 2 rattan-palms from Malaysia. A good fixation of chromium and copper took place in cocos-palm after 4 weeks storage at 28°C. Nevertheless the fixation was slower than in pine-wood and demanded an elevated t...
H Willeitner, K Brandt
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
Moderate temperature fixation of CCA-C
1989 - IRG/WP 3522
Several Canadian treating plants are using moderate temperature (40-60C°) fixation chambers to reduce drippage and leaching from fresh CCA treated wood. In this study, chromium reduction and surface leaching properties of CCA-C treated red pine (Pinus resinosa) pole sections were monitored during exposure to temperatures of 50-60C° and 90-100% RH conditions. Chromium-VI concentration in the abso...
P A Cooper, Y T Ung
Effect of species, retention and conditioning temperature on copper stabilization and leaching for ACQ-D
2004 - IRG/WP 04-30342
The time to stabilization or equalization of the copper component of ACQ-D was highly dependent on treating solution concentration (preservative retention) and post treatment temperature. Stabilization was rapid for low preservative retentions but extended times were needed for wood treated with higher concentration solutions. The extent of stabilization was also concentration dependent with a h...
Y T Ung, P A Cooper
New experiences with Dry Rot in Danish buildings, heat treatment and viability tests
1989 - IRG/WP 1423
An increasing number of concealed dry rot attacks, especially in older multi-storey houses under renovation, have been detected during the last few years. A necessary consequence is a demand for cheaper methods of repair, compared to the standard method used in Denmark for many years otherwise severely attacked houses will by pulled down. A heat-treatment has been developed and tested in practice....
A P Koch, C Kjerulf-Jensen, B Madsen
Sterilization to limit pretreatment decay: Internal temperature during kiln drying of Douglas-fir poles
2001 - IRG/WP 01-40206
Sterilization to limit pretreatment decay: Internal temperature during kiln drying of Douglas-fir poles. Fungal colonization of poles following peeling has been the subject of considerable concern among electric utilities. While the presence of fungi does not, in itself constitute a risk, the survival of these fungi through the conventional treating processes could allow them to continue to degrad...
J J Morrell, P G Forsyth, K L Levien
Extracellular mucilage (ECM) in wood decay basidiomycetes
2002 - IRG/WP 02-10439
The ability of wood decay basidiomycetes to produce extracellular mucilage (ECM) and its relationship with total biomass production is being investigated. Growth and ECM production by the brown-rot fungus Gloeophyllum trabeum (FPRL 108 N) and the white-rot fungus Coriolus versicolor (CTB 863 A) was assessed in liquid culture under different conditions and in the presence of the fungicide cyprocona...
D Vesentini, D J Dickinson, R J Murphy
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