Your search resulted in 24 documents.
Intraspecific variability in feeding capacity of Coptotermes acinaciformis (Froggatt) (Isoptera: Rhinotermitidae)
1983 - IRG/WP 1175
This paper describes laboratory studies to evaluate the comparative feeding capacity within and between five mound colonies of Coptotermes acinaciformis (Froggatt). Matched specimens of mountain ash, pine and coachwood were exposed to five replicate 10 g groups of termites from each colony source. After an initial 8-week exposure period, all groups were assessed for vitality and continued feeding ...
C D Howick, J W Creffield
Intraspecific variability of durability of Wapa courbaril (Eperua grandiflora) against Antrodia sp. and Coriolus versicolor: effect of radial and height position in the stem
2004 - IRG/WP 04-10531
The variation of a lesser-used species, Eperua grandiflora attacked by brown and white rot has been examined. Trees of this specie showed differences in their behaviour against the type of rot used and also showed evidence of intra and inter tree variation. The “tree” effect is very significant concerning natural resistance. In the same way, there is variation of durability observed according ...
N Amusant, J Beauchêne, M Fournier
How intraspecific radial variability of the European Oak’s may influence mild pyrolysis process and durability of the material
2016 - IRG/WP 16-40725
Last decades wood is promoted as building material. Unprotected wood exposed to outdoor conditions undergoes a variety of degradation induced essentially by fungi attacks. Heat treatment of wood by mild pyrolysis (180°C T 240°C under inert atmosphere) is a preservation process with a weak environmental impact, and therefore, is viewed as an interesting alternative to the chemical impregnation me...
J Hamada, A Pétrissans, F Mothe, M Pétrissans, P Gérardin
Preliminary study of the fungicidal and structural variability in copper naphthenates and naphthenic acids
1996 - IRG/WP 96-30114
Copper naphthenates, an oil-borne wood preservative listed by the American Wood-Preservers' Association (AWPA), is manufactured by complexing copper(II) with naphthenic acids. Prior to AWPA listing as a wood preservative, field experiments showed that copper naphthenates generally had good stability and were active against wood-destroying organisms. Recently, however, there have been reports ...
T Schultz, D D Nicholas, L L Ingram Jr, T H Fisher
Interspecific variability of European oak durability against white rot fungi (Coriolus versicolor): Comparison between sessile oak and peduncle oak (Quercus petraea and Quercus robur)
2001 - IRG/WP 01-10393
The knowledge of wood natural durability against biologic predators enable its external use. The resistance of European oak wood was reported like durable according to the EN 350-2. However, some individuals may contain high durable wood. Our research was focused to understand this variability in oak population that represent the first french species (4.1 millions of ha). Natural durability of Eur...
N Ayadi, B Charrier, M Irmouli, J P Charpentier, C J Allemand, F Feuillat, R Keller
Implications for comparability of laboratory experiments revealed in studies on the variability in survival and wood consumption between colonies of Coptotermes acinaciformis (Froggatt) (Isoptera: Rhinotermitidae
1983 - IRG/WP 1196
(Summary of paper 1193)
Groups of Coptotermes acinaciformis, originating from six colonies, three taken from each of two localities, 1500 km apart, in northern Australia (Townsville, Darwin) were kept at population densities of 0.005, 0.01 and 0.02 g termites/mL. Survival and wood consumption of the groups after 8 weeks followed a similar pattern in the colonies from both collection areas. Groups were least vigorous at the lowest population density; their performance reached a maximum at a population density of 0.01 g/mL. The subsequent decline in vigour was less marked as the highest population density was approached. However, the actual values for survival and wood consumption varied widely between colonies, irrespective of their origin. It is recommended that in all laboratory experiments which use survival and wood consumption as indicators of termite vigour, controls of a favourable as well as an unfavourable food type are included which would serve to monitor the vigour of the termites. Results from termite sources whose vigour falls below a certain threshold value would have to be treated with caution and could not be used in definative data, as e.g. in defining critical retentions of wood preservatives.
M Lenz
The variability of preservative distribution in test blocks
1973 - IRG/WP 220
The techniques for the assessment of likely effectiveness of preservative systems have long been the subject of much discussion. The whole field has recently been reviewed by Hilditch and Hamblyn (1971) who described in detail many of the laboratory test procedures used, but who also indicated the deficiencies in many of these techniques. It has long been the view of many associated with the wood ...
F W Brooks, M R Gayles, R W Watson
A study of decay type variability in variously treated Fagus sylvatica and Pinus radiata field test stakes exposed at a vineyard for 30 - 45 months
1998 - IRG/WP 98-10271
Pinus radiata test stakes were treated with 10 kg/m3 of CCA plus 4 lower retentions in a geometric series of 1.5. Fagus sylvatica was treated with 15 kg/m3 and 2 lower retentions. Both timber species were also treated with equivalent retentions of various new generation preservatives (P. radiata was also treated with creosote). Whilst these stakes were exposed at 11 sites in New Zealand (NZ) and 2...
R N Wakeling, A P Singh
Influence of clonal variability on the impregnability of poplar hybrids. (+ correction document of 23 April 1990)
1990 - IRG/WP 3614
The new Western European poplar clones (Populus nigra x deltoides and Populus trichocarpa x deltoides) were compared with the reference clone 'Robusta' and some old hybrids. Samples (5x5x50 cm³) with pure tangential/radial surfaces were sawn, including the transition zone between heartwood and sapwood. Treatment by a standard vacuum-pressure impregnation cycle with CCA showed a ...
J Van Acker Van, M Stevens, C De Haas
Implications for comparibility of laboratory experiments revealed in studies on the variability in survival and wood consumption between colonies of Coptotermes acinaciformis (Froggatt) (Isoptera: Rhinotermitidae
1983 - IRG/WP 1193
Groups of Coptotermes acinaciformis originating from six colonies, three taken from each of two localities 1500 km apart in northern Australia (Townsville, Darwin), were kept at population densities of 0.005, 0.011 and 0.02 g termites/mL. Survival and wood consumption of the groups after 8 weeks followed a similar pattern in the colonies from both collection areas. Groups were least vigorous at th...
M Lenz
Principles behind the laboratory assessment of materials with subterranean termites - Recent perspectives and shifts in emphasis
1986 - IRG/WP 1291
Laboratory assessments of materials against termites aim to give an indication of the likely performance of materials in the field. To meet this objective, test procedures have to provide the conditions that promote the most vigorous activity of the insects. Implications of recent findings on inter- and intracolony variability in vigour, the need to monitor termite activity with differing types of...
M Lenz
Variation in field test performance of untreated and CCA-treated lesser-known Surinamese wood species
2000 - IRG/WP 00-20213
In Suriname three different field test sites have been used to verify the biological durability of CCA-treated wood and a range of wood species including lesser-known and lesser-used wood species. In total 37 tropical wood species were tested untreated and for 17 of the less durable species CCA-treatments were included as well. Although the three sites are located in the tropical region they diffe...
J Van Acker, M Stevens, L Comvalius
Biological variability in the oxalate/oxalate decarboxylase system among five isolates of the wood-degrading fungus Meruliporia incrassate
2006 - IRG/WP 06-10573
The “dry-rot” wood decay fungus Meruliporia incrassata has recently attracted attention, primarily in the western coastal United States, as a particularly destructive pest of building material. Recently, the US Environmental Protection Agency (EPA) has accepted a voluntary withdrawal of the historically effective chromated-copper arsenate (CCA) as a preservative for wood used in residential se...
C Howell, J Jellison
Evaluation of variables that influence dynamic MOE in wood decay studies
2009 - IRG/WP 09-20409
The effect of wood moisture content (MC) and outdoor exposure of southern pine lap-joint components on dynamic MOE values was investigated. The use of dynamic MOE as a method of measuring progressive biodeterioration of above ground test samples shows promise, but the accuracy of this method for evaluating test samples subjected to fluctuating environmental conditions has not been reported. The re...
D Nicholas, J Shi, T Schultz
Onset of mould growth – the effect of climate variability and different geographic locations
2010 - IRG/WP 10-20446
This paper presents a study on how climate conditions at numerous locations in Sweden affect the risk of onset of mould on wood sheltered outdoors. The results indicate that the risk is clearly higher in the south compared to the north of Sweden. These differences are mainly explained by colder and dryer winter periods in the north which is unfavorable for development of mould. The results also sh...
M Häglund, T Isaksson, S Thelandersson
Limited variability in biological durability of thermally modified timber using vacuum based technology
2011 - IRG/WP 11-40567
The SmartHeat® thermal timber treatment is a new technology based on the process parameters being steered very precisely mainly due to the vacuum applied and heating system involved. Timber treated with this technology shows a potential for less variability of biological durability in one batch. Several batch treatments were sampled and assessed on statistical variability of decay resistance agai...
J Van Acker, S Michon, J Van den Bulcke, I De Windt, B Van Swaay, M Stevens
In-ground variability of decay intensity within a test field
2012 - IRG/WP 12-20496
Timber exposed in the ground faces most severe conditions in terms of exposure to wetting and fungal decay in the terrestrial environment, therefore wood durability tests are often conducted in test fields preferably ensuring the occurrence of all relevant decay organisms. One can also expect differences in decay within an individual field-test site due to localized distribution of certain organis...
C Brischke, S Olberding, L Meyer, T Bornemann, C R Welzbacher
Variability in durability of some selected South-American wood species
2014 - IRG/WP 14-10831
Within the scope of sustainable forest management one wants to encourage the proper use of lesser known wood species. Therefore the market has to shift from a demand-driven towards a supply-driven market without loss of wood quality. It is generally known that the durability from pith to bark varies thus, affecting the overall durability of wood species. Consequently, a detailed analysis is necess...
I De Windt, P ’t Hooft, J Van den Bulcke, J Van Acker
The potential of 2D NIR imaging for wood protection research
2015 - IRG/WP 15-20566
Investigating wood and wood-based materials using infrared spectroscopy has since long been explored. Recently, image-based systems have been developed that are used in food and pharmaceutical industries for rapid screening. Such hyperspectral cameras are able to collect spatial and spectral information simultaneously, resulting in a volume with a spectral profile for each pixel of the image. We p...
J Van den Bulcke, N Defoirdt, W Li, J Van Acker
Effect of natural variability of European Oak wood on heat treatment process and potential implication on wood durability
2015 - IRG/WP 15-40693
Environmental pressures appeared in France and in most European countries during the last decade has led to the development of more environmentally acceptable preservation methods. In this context, wood heat treatment has been one of the most investigated alternative method during the last years. Treated at temperatures ranging between 180 and 220°C, wood components undergo more or less important...
J Hamada, A Pétrissans, F Mothe, M Pétrissans, P Gérardin
Global survey on durability variation – on the effect of the reference species
2016 - IRG/WP 16-20573
Climate change due to anthropogenic emissions is the largest environmental challenge of our time. Forest-based value chains play an important role in reducing the accumulation of CO2 in the atmosphere. Maximizing the use of wood to tackle climate change requires improved understanding of the service life of timber products. This information can best be obtained from field testing and while there i...
R Stirling, G Alfredsen, C Brischke, I De Windt, L P Francis, E Frühwald Hansson, M Humar, J Jermer, M Klamer, M Kutnik, P Laks, I Le Bayon, S Metsä-Kortelainen, L Meyer-Veltrup, P I Morris, J Norton, T Singh, J Van Acker, J Van den Bulcke, T M Venås, H Viitanen, A H H Wong
Modelling the performance of bio-based building materials
2016 - IRG/WP 16-20582
The ‘bio-based economy’ represents a growing area of development globally and covers a wide range of building materials including wood and wood-based products. A ‘bio-based’ material is intentionally made from substances derived from living (or once-living) organisms. In this context it means that the materials and products are made from renewable resources, with the criteria that a renewa...
C Brischke
Evaluation of field test data
2016 - IRG/WP 16-20594
The resistance against fungal decay and insect attack of wood can be highly variable, between boards and even within boards. The variability in durability is not always an issue, but for high demanding applications information about its reliability is required. This comprises the variability of outdoor performance. Durability testing in laboratory and outdoor exposures can provide a good basis to ...
F Bongers, C Brischke, J Van den Bulcke, W Gard, I De Windt, H Militz
Decay resistance variability of European wood species thermally modified by industrial process
2017 - IRG/WP 17-40807
Thermal modification is now considered as a new ecofriendly industrial wood modification process improving mainly the material decay resistance and its dimensional stability. Most industrial thermal treatment processes use convection heat transfer which induces sometimes heterogeneous treatment temperature propagation within the oven and lead to the heterogeneity in treatment efficiency. Thus, it ...
K Candelier, L Pignolet, S Lotte, A Guyot, E Cuny, B Bousseau, M-F Thévenon