Your search resulted in 120 documents. Displaying 25 entries per page.
Influence of a pulsed electric field on the growth of surface fungi
2013 - IRG/WP 13-10795
The colonization of mold and staining fungi are not only an aesthetical problem. Blue stain fungi are able to penetrate paint films. Maintenance of coatings on wood are time consuming and costly. A new approach uses a pulsed electric field (PLEOT) in order to protect wood against surface fungi. This technology is evaluated in non-sterile laboratory conditions on different coated and uncoated Scots...
M Starck, A Treu
Using hyperspectral imaging to detect and quantify mould and blue stain on coated and uncoated wood
2014 - IRG/WP 14-10822
Hyperspectral imaging has been applied on the surface of samples of coated and uncoated Norway spruce (Picea abies) as a new technique to detect and quantify growth of mould and blue stain fungi. Principal Component Analysis of the hyperspectral images resulted in a clear visualization of the fungi and the amount of mould coverage could be estimated. This indicates that NIR hyperspectral imaging c...
L Ross Gobakken, I Burud, A Flø, K Kvaal, T K Thiis
The role of hydrophobins in surface growth by the Blue Stain fungi Aureobasidium pullulans
2015 - IRG/WP 15-10837
Hydrophobins are small proteins found exclusively in filamentous fungi. These proteins are able to assemble spontaneously into amphiphilic monolayers at hydrophobic–hydrophilic interfaces. Hydrophobins have a diverse role, e.g. allowing the fungi to break through interfaces during aerial hyphae formation, sporulation, fruit body production and cell penetration. In this ongoing study, we are look...
J Stenbæk, L Riber, J Blæsbjerg Nielsen, C Møller Hansen, B Jensen
Mould growth on spruce claddings and the effect of selected influencing factors after 4 years of outdoor testing
2015 - IRG/WP 15-30671
Norway spruce (Picea abies) is the most frequently chosen wood species as claddings in façades in Norway, and is used both coated and uncoated. The visual changes that occur during weathering can be colour changes, abrasion or wear, blistering, flaking, and even cracks in the wood or coating, but more often growth of mould and blue stain fungi is the main challenge. A field test with synchronous monitoring of relative humidity, air temperature, material temperature and wood moisture content in Norway spruce claddings has been performed in southern Norway as part of the ClimateLife project. Visual evaluation of blue stain and mould growth according to EN 927-3 was performed, and evaluation data after 46 months exposure is presented. The objectives were to study the effect of 1) environment, 2) cardinal direction and 3) colour of the coated surface on growth of blue stain and mould fungi and to study the variation in relative humidity, air temperature, wood moisture content and material temperature. After 46 months exposure, the red coating system had generally the lowest mould ratings and the uncoated claddings had the highest. Of the white coloured claddings the ones facing south had lower mould ratings than those facing north, but the opposite were found for red coloured claddings. The relative humidity was higher in front of claddings exposed northwards and in a shaded environment compared to an open environment against south. In an open environment red coloured claddings had the lowest wood moisture content and highest material temperature, and red coloured claddings against south had the highest maximum material temperature.
L Ross Gobakken, G I Vestøl
Susceptibility of wood substrates to Aurebasidium pullulans at different temperatures
2016 - IRG/WP 16-10863
There is an increasing awareness of how the aesthetical performance of wood exposed outdoors changes over time and especially in the first few years after installation. Mould and blue stain fungi are biological agents that contribute to the weather grey colour on a wooden façade, and the blue stain fungi Aureobasidium pullulans is commonly identified as colonizer on coated and uncoated wood expos...
L Ross Gobakken, G Alfredsen
New approach to improve the estimation of colony population in subterranean termites (Blattodea: Rhinotermitidae)
2016 - IRG/WP 16-10866
The aim of this study was to estimate the mortality and fading effects of dye markers Neutral red and Nile blue commonly used in the estimation of termite colony population, in order to determine the decrease rate from the initial number of marked and released termites. This rate can be considered in the application of the different indexes used to calculate the number of termites of the colony. I...
E Alcaide, R Molero, J Diz, M Gaju
Identification of the key factors influencing development of the blue stain fungi
2016 - IRG/WP 16-10872
Service life of wood is more and more frequently affected by aesthetic requirements than functional ones. In order to elucidate various aspects of service life, model house with façade elements made of 22 materials was built on the field test site at Department of Wood Science and Technology in Ljubljana. Colour and fungal disfigurement is among other parameters monitored on this house. In parall...
D Kržišnik, B Lesar, N Thaler, M Humar
Assessment of the biological durability of wood treated with organosilicon compounds
2016 - IRG/WP 16-30685
The European wood construction market is in need of environmentally friendly wood-based products whose service life meets the expectations of end users. Non-biocidal silicon-based water repellents, which can be applied to different materials, help minimize their vulnerability/susceptibility to liquid water. Consequently, they have the potential of increasing wood’s resistance against decay fungi...
M Kutnik, M Montibus, S Derocker, S Salivati, J-P Lecomte
Effects of climatic factors and material properties on mould growth on untreated wooden claddings
2017 - IRG/WP 17-10884
Mould growth is an important contributor to colour change of untreated wood exposed outdoors. Predicting the development of mould growth is therefore important to ensure successful use of untreated wood as a façade material. More knowledge about the factors affecting mould growth on outdoor exposed wood is required to give better predictions. In this study, climatic factors and material propertie...
S Karlsen Lie, G I Vestøl, O Høibø, L Ross Gobakken
Fungal growth on coated wood exposed outdoors: influence of coating pigmentation, cardinal direction and inclination of wood surfaces
2017 - IRG/WP 17-10896
The objective of the SERVOWOOD project was to develop and establish European Standards that will facilitate the prediction of service life for exterior wood coatings. One of the objective of this project was to study fungal growth of the field exposed panels. Two coatings applied in 2 and 3 coats were exposed for one year outdoors at 45° south: one solventborne (alkyd based) and one waterborne (a...
L Podgorski, C Reynaud, M Montibus
Bio-friendly wood protection systems - resistance to mould and blue-stain fungi
2017 - IRG/WP 17-30713
With stricter restrictions on the use of biocides and increasing environmental awareness there is a pronounced need for effective bio-friendly protection systems in the wood preservative and wood coating industry. One of the possible pathways is to exploit and utilize natural substances with active biological effects. Silanes, caffeine, natural oils and potassium carbonate were chosen as compounds...
L Ross Gobakken, W Perdoch, B Mazela, P Kwaśniewska-Sip, G Cofta
Plasma-assisted bleaching of blue-stain from lodgepole pine wood
2017 - IRG/WP 17-40799
We hypothesize that plasma will etch wood and fungal hyphae in blue-stained lodgepole pine, and increase the ability of hypochlorite bleach to remove discolouration from blue-stained wood. Blue-stained lodgepole pine wood was exposed to a glow-discharge plasma derived from water, and the surface wettability, permeability and colour of the treated wood was measured. Plasma-treated wood was dipped i...
A Jamali, P D Evans
Visual appearance of unpainted wooden claddings during the first year of outdoor exposure: Evaluation of surface mould growth, lightness (L*) and wasp attack
2018 - IRG/WP 18-40841
This study addresses changes in visual appearance of unpainted wood materials exposed outdoors. Specimens of Norway spruce (Picea abies) Scots pine (Pinus sylvestris), aspen (Populus tremula), acetylated Radiata pine (Pinus radiata) and DMDHEU-modified Scots pine sapwood were exposed facing south in Ås, Norway for 60 weeks. During this period, surface mould growth development and wasp attack were...
S Karlsen Lie, L Ross Gobakken, G I Vestøl, O Høibø
Performance of untreated timbers in above ground decking tests: Preliminary results from an international collaborative trial
2019 - IRG/WP 19-10940
The ability to accurately predict wood decay risks under varying environmental conditions has long been of interest to timber users. Accurate predictions are difficult owing to the myriad of variables associated with the decay process including wood species, wood inhabiting organisms, timber building element design and environmental conditions. Despite these difficulties, decay predictions have be...
L P Francis, J Norton, E Melcher, A H H Wong, J Kok Lai, M Klamer, M J Konkler, J J. Morrell
Enhancing the durability of low durability Eucalyptus plantation species: a review of strategies
2020 - IRG/WP 20-40910
Eucalyptus species native to Australia have shown excellent growth rates, good physical properties and resistance to diseases. As a result, they are widely planted globally for a variety of uses. One negative aspect of many of these faster growing species is that they have a high percentage of low durability heartwood that resists preservative treatment. In Australia, large plantations of these sp...
K C Wood, J J Morrell, W Leggate
A simple method for assessing the effects of lyctid beetle attack on longitudinal compressive strength of spotted gum sapwood
2023 - IRG/WP 23-20700
Lyctid beetle attack is commonplace in a significant proportion of spotted gum utility poles that are air seasoned prior to chromated copper arsenate (CCA) treatment. While this damage is allowed, there are no reports quantifying the effects of the beetle galleries on pole properties. Full scale testing would require substantial quantities of poles in order to obtain a range of degrees of damage....
M Powell, J J Morrell
Establishing the minimum effective penetration of wood preservatives in the refractory heartwood of E. nitens
2023 - IRG/WP 23-30780
Conventional pressure treatment of many Australian hardwoods results in little to no penetration of heartwood and a non-uniform envelope treatment of <5 mm surrounding a mostly untreated core. This is a major issue for many of the low durability plantation hardwood timbers that are grown in Tasmania, which contain high percentages of heartwood. Long term studies on softwoods such as spruce decking...
J R Vargas, J J Morrell, L Yermán, K C Wood
Influence of weathering of wood surfaces before and after treatment with iron(II) sulphate
2023 - IRG/WP 23-30786
Outdoor wood is exposed to various factors that cause the wood to grey or age. The ageing processes can vary greatly depending on the exposure. Parts of the wood that are not exposed to external factors, e.g. under the eaves, are less exposed and the ageing process is therefore slower. This can be accelerated by solutions based on iron ions. In this way, the wood greys quickly and evenly. However,...
B Lesar, M Humar, F Osvald
Short-term absorption of water and coatings on thermally modified blue-stained spruce wood
2023 - IRG/WP 23-40984
The importance of wood has been increasing in the last decades. Among conifers, predominantly spruce (Picea abies) wood is often used in building constructions in Europe. Namely for construction and facades of buildings, decking and fences. Due to the increased public concerns about biocides, alternative techniques for protection, such as thermal modification and protection by construction, are ga...
R Hasanagic, M Bahmani, M Humar, L Fathi, L Cai
Comparison of residual Methylisothiocyanate (MITC) in Australian and South American hardwood and softwood treated with a solid compressed Dazomet fumigant stick
2024 - IRG/WP 24-20712
The efficacy of compressed dazomet sticks with or without a copper-based accelerant for control of internal decay of both softwood and hardwood species was examined in multiple field trials. Effective levels of methylisothiocyanate (MITC), the fungitoxic decomposition product of dazomet were found in Australian spotted gum (Corymbia spp) and Guyanese Wallaba (Eperua falcata) as well as in southern...
R Tungal, M Powell, J J Morrell, T Singh