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1
Kumar, N. Praveen, and Arun Arya. "Delignification of Valuable Timbers Decayed by India Lignicolous Fungi." International Letters of Natural Sciences 16 (May 2014): 101–20. http://dx.doi.org/10.18052/www.scipress.com/ilns.16.101.
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Wood degrading capacity of lignicolous fungi was studied by decay test. In which two methods were followed, i) wood chips method ii) wood block method. Eight timbers infected by six fungi were selected for studying percentage of decay and biochemical test was done to know delignification. After 12 months, 90 % of wood block of T. arjuna was decayed by L. stereoides. In teak wood 16.82 % of decay was due to H. apiaria in 3 months. As the percentage of moisture was less, percentage of weight loss was also less; this indicated that decay capacity of fungi will depends on % moisture content in wood. The percentage loss in hot water soluble substrates was more in case of T. crenulata due to L. stereoides for 5 months, whereas lowest in case of teak wood decayed by H. apiaria for 5 months. The percentage loss in ethanol benzene soluble substrate was more in case of Adina wood decayed by C. versicolor for 5 months, whereas lowest in case of teak wood infected with L. stereoides for 3 months. As the incubation period increases, percentage loss in acid soluble lignin was more in case of infected woods. L. stereoides, C. versicolor, and H. apiaria showed selective delignification in all infected woods, whereas T. pini showed simultaneous degradation of lignin in all woods tested. The valuable timber like teak wood was not resistant to wood decay because they loss 50% of lignin. The in vitro wood decay test can‟t be taken as absolute evidence for wood decay behavior of lignin-degrading fungi, so we should conform decay of wood by consider biochemical test. For rapid evaluation of wood decay the wood chip method was best suitable. For the first time the wood decay and biochemical test of 8 wood samples infected by white rot fungi like S. commune, L. stereoides, H. apiaria, C. versicolor, T. pini and soft rot fungi like T. viride was studied.
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Li, Gan, Darrel D. Nicholas, and Tor P. Schultz. "Development of an accelerated soil-contact decay test." Holzforschung 61, no. 2 (2007): 214–18. http://dx.doi.org/10.1515/hf.2007.037.
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Abstract An accelerated method to evaluate wood preservatives for soil contact was explored using thin (4 mm) pine sticks in small decay cups containing non-sterile soil and wood compost-amended soil. The extent of wood decay was measured by monitoring changes in the bending elasticity (MOE) of the test samples, which was found to be a sensitive measure of the decay extent for both chromated copper arsenate (CCA)- and copper naphthenate (CuNap)-treated wood, and untreated wood. The decay rate was rapid, with significant decay detected in untreated wood after only 2 months of exposure. Decay in both treated and untreated wood samples was observed sooner when the soil was amended with wood compost. The compost-amended soil also gave significantly higher copper depletion for CCA- but not CuNap-treated wood. Although the results from this test should not be extrapolated to predict field test performance, it does appear to be applicable for rapid comparison of the performance of new and established preservative systems.
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Rahman, Md Rezaur, Sinin Hamdan, M. Saiful Islam, and Md Shahjahan Mondol. "Mechanical Properties and Decay Resistance of Wood Polymer Composites (WPC)." Advanced Materials Research 264-265 (June 2011): 819–24. http://dx.doi.org/10.4028/www.scientific.net/amr.264-265.819.
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In Malaysia, especially Borneo Island Sarawak has a large scale of tropical wood species. In this study, selected raw tropical wood species namely Artocarpus Elasticus, Artocarpus Rigidus, Xylopia Spp, Koompassia Malaccensis and Eugenia Spp were chemically treated with sodium meta periodate to convert them into wood polymer composites. Manufactured wood polymer composites were characterized using mechanical testing (modulus of elasticity (MOE), modulus of rupture (MOR), static Young’s modulus) and decay resistance test. Modulus of elasticity and modulus of rupture were calculated using three point bending test. Static Young’s modulus and decay resistance were calculated using compression parallel to gain test and natural laboratory decay test respectively. The manufactured wood polymer composites yielded higher modulus of elasticity, modulus of rupture and static Young’s modulus. Wood polymer composite had high resistant to decay exposure, while Eugenia Spp wood polymer composite had highly resistant compared to the other ones.
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Emmerich, Lukas, Maja Bleckmann, Sarah Strohbusch, Christian Brischke, Susanne Bollmus, and Holger Militz. "Growth behavior of wood-destroying fungi in chemically modified wood: wood degradation and translocation of nitrogen compounds." Holzforschung 75, no. 9 (2021): 786–97. http://dx.doi.org/10.1515/hf-2020-0252.
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Abstract Chemical wood modification has been used to modify wood and improve its decay resistance. However, the mode of protective action is still not fully understood. Occasionally, outdoor products made from chemically modified timber (CMT) show internal decay while their outer shell remains intact. Hence, it was hypothesized that wood decay fungi may grow through CMT without losing their capability to degrade non-modified wood. This study aimed at developing a laboratory test set-up to investigate (1) whether decay fungi grow through CMT and (2) retain their ability to degrade non-modified wood. Acetylated and 1,3-dimethylol-4,5-dihydroxyethyleneurea (DMDHEU) treated wood were used in decay tests with modified ‘mantle specimens’ and untreated ‘core dowels’. It became evident that white rot (Trametes versicolor), brown rot (Coniophora puteana) and soft rot fungi can grow through CMT without losing their ability to degrade untreated wood. Consequently, full volume impregnation of wood with the modifying agent is required to achieve complete protection of wooden products. In decay tests with DMDHEU treated specimens, significant amounts of apparently non-fixated DMDHEU were translocated from modified mantle specimens to untreated wood cores. A diffusion-driven transport of nitrogen and DMDHEU seemed to be responsible for mass translocation during decay testing.
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De Groot, Rodney C. "Test assemblies for monitoring decay in wood exposed above ground." International Biodeterioration & Biodegradation 29, no. 2 (1992): 151–75. http://dx.doi.org/10.1016/0964-8305(92)90014-f.
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Richter, Dana L., Amy M. Berns, and Clare F. Frederick. "Resistance of Canada Yew (Taxus canadensis) Branch Wood to Two Wood Decay Fungi." Canadian Field-Naturalist 126, no. 2 (2012): 160. http://dx.doi.org/10.22621/cfn.v126i2.1334.
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Wood of the larger yews (Taxus spp.) is reported to be decay-resistant, but little is known about the decay resistance of Canada Yew (Taxus canadensis Marsh.) wood. Branch wood from Canada Yew was compared to branch wood from Northern Red Oak (Quercus rubra L.) and Eastern White Cedar (Thuja occidentalis L.) in a standard laboratory decay test to evaluate its resistance to decay by two decay fungi. Canada Yew was shown to be significantly more resistant to decay by Gloeophyllum trabeum (Pers.) Murr. (a brown rot fungus) and Trametes versicolor (L.: Fr.) Quél. (a white rot fungus) than Northern Red Oak (P ≤ 0.05). Canada Yew was shown to be equal to Eastern White Cedar in resistance to decay by G. trabeum and more than twice as resistant to decay by Trametes versicolor (P ≤ 0.05). These results may have relevance for survival of Canada Yew, which is under pressure from browsing by White-tailed Deer (Odocoileus virginianus).
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Vanpachtenbeke, Michiel, Jan Van den Bulcke, Joris Van Acker, and Staf Roels. "Performance of wood and wood-based materials regarding fungal decay." E3S Web of Conferences 172 (2020): 20010. http://dx.doi.org/10.1051/e3sconf/202017220010.
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Due to the increasingly stringent energy efficiency requirements, timber frame houses are becoming more and more popular across Europe. Depending on the circumstances, timber frame walls might be exposed to high relative humidity or condensation conditions, leading to a risk of fungal degradation. In order to assess the durability of a timber frame construction in a reliable way, a clear view on the potential risk of fungal growth is essential. Various experiments are reported in literature to define the minimal moisture threshold for fungal decay, yet all very different in set-up and hence leading to contradictory conclusions. Therefore, the present paper aims at a contribution to a better understanding of the influence of moisture conditions on the onset and progress of wood decay in timber frame walls. Based on the information that is still lacking in international literature, a new test methodology has been elaborated within this work and is reported in this paper.
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Holan, Jiří, and Blanka Stávková. "The comparison of properties of European beech Fagus sylvatica (L.) in different stage of degradation caused by wood-decay fungi." Acta Universitatis Agriculturae et Silviculturae Mendelianae Brunensis 57, no. 5 (2009): 119–30. http://dx.doi.org/10.11118/actaun200957050119.
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This work focus on comparison of biological degradation of wood caused by wood-decay fungi (white and brown rot). Test samples were made of European Beech Fagus sylvatica (L.). As wood-decay fungi were used Trametes versicolor (L.) Lloyd (white rot) and Serpula lacrymans (Wulf. Ex Fr.) Schroet (brown rot). Aim of this work was comparison of rate of propagation of wood-decay fungus and degradation of wood in time. After termination of the test was made comparison of intensity of degradation between both fungi species. Weights of test samples were diminishing for both groups of wood-decay fungi during three months. Moisture content increased in direct proportion with time. Compression strength in direction of wood fibers of tested samples was diminishing. Samples tested by Serpula lacrymans had the fastest decrease of compression strength after first and second week of degradation. Samples tested by Trametes versicolor had different course. Compression strength significantly decreased after first month and third month of degradation. On the other hand module of elasticity of both tested groups was diminishing already during first and second week of degradation. Generally, it is possible to say that Trametes versicolor has more significant impact on changes of mechanical characteristic of wood, because it causes degradation of all chemical constituents of wood.
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Nicholas, Darrel D. "Effect of Nitrogen and Vitamins on the Decay Rate of Pine Sapwood Exposed above Ground." Forest Products Journal 71, no. 1 (2021): 39–41. http://dx.doi.org/10.13073/fpj-d-20-00072.
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Abstract A need exists to develop improved test methods for evaluating potential wood preservatives in aboveground outdoor exposure. Our studies have shown that the three-component lap joint specified in AWPA Standard E27-15 represents an improved design for aboveground testing. One option for evaluating the extent of decay with this method relies on visual assessment. However, based on my observations in field tests, this assessment method does not provide an accurate measurement of the extent of wood biodeterioration in the early stages of decay. A second method of evaluation provided in this standard (in figure 4 of the standard) uses bending stiffness and dynamic modulus of elasticity (MOE) as alternate methods for determining the extent of decay, and this option was chosen to follow the progress of biodeterioration in this study. It was found that both of these methods provided an accurate assessment of decay in the early stages of biodeterioration that was superior to visual assessment. In an attempt to accelerate the rate of wood decay, some of the test units were treated with nitrogen-rich casein, and this resulted in a greater than twofold increase in the decay rate compared with the untreated controls. Another group of samples were treated with thiamin, but this resulted in only a slight increase in decay rate, whereas a combined treatment with both casein and vitamins resulted in a further increase in the decay rate beyond that of casein treated samples. Based on the results from this study, it is concluded that pretreatment of wood samples with thiamin has the potential for accelerating wood decay in aboveground test samples. Furthermore, the use of bending stiffness and dynamic MOE to measure the extent of wood decay was found to be superior to mass loss. Additional studies are needed to determine whether this concept could be useful in accelerating development of new wood preservatives.
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A.R, Noor Azrieda, Salmiah U, and Rahim S. "Comparison of Accelerated Decay and Graveyard Test on Selected Malaysian Timber Species." Journal of Tropical Resources and Sustainable Science (JTRSS) 3, no. 1 (2015): 238–41. http://dx.doi.org/10.47253/jtrss.v3i1.702.
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The natural durability of timber may be defined as ‘inherent resist ance of timber to attackby wood deteriorat ion agents such as wood decay ing fungi and wood destroying insects’. In Malay sia, natural durabilit y of t imber is det ermined using a ‘gravey ard’ test . The average time taken for this test is more than 10 years. The results of this test method donot provide information on longevity (service life) either out of ground contact, or inother geographical locations. Comparison of natural durability requires the use ofstandard test method where for example in Europe, the accepted laboratory method is EN350-1. This paper briefly describes the rating of natural durability based on comparisonresults of the two test methods stated i.e the exterior graveyard test and the interior laboratory test.
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Sefidi, Kiomars, and Vahid Etemad. "Dead wood characteristics influencing macrofungi species abundance and diversity in Caspian natural beech (Fagus orientalis Lipsky) forests." Forest Systems 24, no. 2 (2015): eSC03. http://dx.doi.org/10.5424/fs/2015242-06039.
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<p><em>Aim of study</em>: This study aimed to examine the dead wood inhabiting macrofungi communities occurring on dead beech and hornbeam trees in Caspian forests.<strong></strong></p><p><em>Area of study</em>: The Kheiroud forest in the north of Iran.</p><p><em>Material and Methods</em>: Data from 205 sampling dead tree were analyzed by means of Generalized Linear Models (GLM) to test the effects of decay stage, DBH, Length or Height on macrofungi diversity. Additionally, tree species, dead wood size, log position, decay stage were used as predictor factors for the number of sporocarps species (NSS) as a fungal species richness and diversity in each dead log using analysis of variance</p><p><em>Main results</em>: The number of sporocarps species (NSS) varied in different dead wood size and decay classes. The different stages of decay and the different size classes of dead wood had significantly different species richness of macrofungi. Deadwood in the high-decayed stages contained the highest diversity of fungi. Most of fungi identified on both logs and snags belonged to Basidiomycetes and Ascomycetes. The highest value for richness and evenness indices calculated in large diameter dead wood in decay class III. The results indicated the size and decay class of dead wood describe the greatest variance of the model that means the highest number of sporocarps species inhabited on the large dead wood in advanced stage of decaying.</p><p><em>Research highlights</em>: Macrofungi diversity varied significantly across pieces of dead wood with downed logs, larger pieces, and wood in later stages of decay having the highest macrofungi diversity.</p><p> <strong>Keywords</strong>: Caspian forest; coarse woody debris; down woody debris; Iran.<strong></strong></p>
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Krause, Kim Christian, Christian Brischke, Tim Koddenberg, Andreas Buschalsky, Holger Militz, and Andreas Krause. "Resistance of Injection Molded Wood-Polypropylene Composites against Basidiomycetes According to EN 15534-1: New Insights on the Test Procedure, Structural Alterations, and Impact of Wood Source." Fibers 7, no. 10 (2019): 92. http://dx.doi.org/10.3390/fib7100092.
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In this study, we investigated injection molded wood-polypropylene composites based on various wood sources and their decay resistance against white rot (Trametes versicolor) and brown rot (Coniophora puteana) in a laboratory test according to EN 15534-1:2014. The manufactured composites consisted of poplar (Populus spp.), willow (Salix spp.), European beech (Fagus sylvatica L.), Norway spruce (Picea abies (L.) H. Karst.), and a commercial wood source (Arbocel® C100), respectively. All formulations were compounded on a co-rotating twin screw extruder and subsequently injection molded to wood–PP specimens with a wood content of 60% or 70% by weight. It was found that the test procedure had a significant effect on the mechanical properties. Loss in mechanical properties was primarily caused by moisture and less by fungal decay. Moisture caused a loss in the modulus of rupture and modulus of elasticity of 34 to 45% and 29 to 73%, respectively. Mean mass and wood mass losses were up to a maximum of 3.7% and 5.3%, respectively. The high resistance against fungal decay was generally attributed to the encapsulation of wood by the polymer matrix caused by sample preparation, and enhanced by reduced moisture uptake during the preconditioning procedure. Notable differences with respect to the wood particle source and decay fungi were also observed. Structural characterization confirmed the decay pattern of the fungi such as void cavities close the surface and the deposition of calcium oxalates.
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Hassan, Babar, Mark E. Mankowski, and Grant T. Kirker. "Evaluation of Heartwood Extracts Combined with Linseed Oil as Wood Preservatives in Field Tests in Southern Mississippi, USA." Insects 12, no. 9 (2021): 803. http://dx.doi.org/10.3390/insects12090803.
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Heartwood extracts of naturally durable wood species are often evaluated as alternatives to chemical wood preservatives, but field data from long-term performance testing are lacking. The current study evaluated the long-term (five-year) performance of two non-durable wood species treated with heartwood extracts of either Tectona grandis, Dalbergia sissoo, Cedrus deodara, or Pinus roxburghii alone or combined with linseed oil. Stakes (45.7 × 1.9 × 1.9 cm) and blocks (12.5 × 3.75 × 2.5 cm) cut from the sapwood of cottonwood and southern pine were vacuum-pressure impregnated with the individual heartwood species extract, linseed oil, or a mixture of each individual wood extract and linseed oil. For comparison, solid heartwood stakes and blocks of the wood species used to obtain extracts were also included in the tests. All samples were exposed for five years to decay and termites at a test site in southern Mississippi using ground contact (AWPA E7) and ground proximity (AWPA E26) tests. Results showed that extract-oil mixtures imparted higher termite and decay resistance in cottonwood and southern pine than linseed oil only or the individual heartwood species extract in both tests. However, these treatments were as not effective as to commercially used wood preservatives, copper naphthenate (CuN) or disodium octaborate tetrahydrate (DOT) in either test. Moreover, solid heartwood P. roxburghii stakes were completely decayed and attacked by termites after five years in the ground contact test. In contrast, C. deodara stakes were slightly attacked by termites and moderately attacked by decay fungi. However, T. grandis and D. sissoo stakes showed slight to superficial attack by termites and decay fungi in ground contact test. In contrast, T. grandis and D. sissoo blocks showed slight decay fungi attack in above-ground tests. However, termites did not attack T. grandis, D. sissoo, and C. deodara blocks. However, decay fungi moderately attacked C. deodara blocks, and P. roxburghii blocks were severely attacked by decay fungi and termites in the above-ground test.
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Mantanis, George I., Charalampos Lykidis, and Antonios N. Papadopoulos. "Durability of Accoya Wood in Ground Stake Testing after 10 Years of Exposure in Greece." Polymers 12, no. 8 (2020): 1638. http://dx.doi.org/10.3390/polym12081638.
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In this research, acetylated wood (Accoya) was tested in ground contact in central Greece. After ten years of exposure during a ground stake test, acetylated pine wood (Pinus radiata) stakes, with a 20% acetyl weight gain, were completely intact and showed no visual decay (decay rating: 0). However, the key mechanical properties of Accoya wood, that is, modulus of elasticity (MOE) and modulus of rupture (MOR) after 10 years of ground contact, were significantly reduced by 32.8% and 29.6%, respectively, despite an excellent visual result since no evidence of fungal attack was identified. This contradiction could possibly indicate that the hallmarks of decay, i.e., brown-rot decay of acetylated wood can be the significant loss of mechanical properties before decay is actually visible.
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Cheesman, Alexander W., Lucas A. Cernusak, and Amy E. Zanne. "Relative roles of termites and saprotrophic microbes as drivers of wood decay: A wood block test." Austral Ecology 43, no. 3 (2017): 257–67. http://dx.doi.org/10.1111/aec.12561.
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Weththimuni, Maduka L., Doretta Capsoni, Marco Malagodi, and Maurizio Licchelli. "Improving Wood Resistance to Decay by Nanostructured ZnO-Based Treatments." Journal of Nanomaterials 2019 (May 2, 2019): 1–11. http://dx.doi.org/10.1155/2019/6715756.
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In this study, the maple wood surface was coated with nanostructured zinc oxide, grown on the surface by using a hydrothermal process, and furtherly treated with shellac varnish. Samples obtained both after ZnO treatment and after the final varnish application were characterized by different techniques, i.e., X-ray diffraction (XRD), scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM-EDS), micro-FTIR with attenuated total reflectance (μ-ATR-FTIR), chromatic variation measurements, and contact angle determinations. Analytical results showed that the wood surface was covered by quite a homogeneous array of inorganic nanoparticles and that the natural resin forms a regular film over the ZnO nanostructures. An accelerated aging test was used to evaluate the protecting effectiveness of the treatments towards UV-induced decay of wood material. After the test, wood treated with ZnO and with the shellac/ZnO combination underwent a considerably lower chromatic change if compared to the untreated wood, suggesting an enhanced resistance of the treated maple to the decay due to light exposition. The presence of nanostructured ZnO protects from decay not only the wood substrate but also the shellac film. A microbiology test showed that growth of fungal species, e.g., common mold, is prevented on the wood surface treated with ZnO or with shellac/ZnO, indicating that the nanostructured zinc oxide also provides an effective protection from biodeterioration. The coating obtained by consecutive application of nanosized ZnO particles and shellac varnish combines the excellent aesthetical features and water repellence of the traditional finish with the protecting effectiveness of the nanostructured inorganic component.
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Alfredsen, Gry, Christian Brischke, Brendan N. Marais, Robert F. A. Stein, Katrin Zimmer, and Miha Humar. "Modelling the Material Resistance of Wood—Part 1: Utilizing Durability Test Data Based on Different Reference Wood Species." Forests 12, no. 5 (2021): 558. http://dx.doi.org/10.3390/f12050558.
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To evaluate the performance of new wood-based products, reference wood species with known performances are included in laboratory and field trials. However, different wood species vary in their durability performance, and there will also be a within-species variation. The primary aim of this paper was to compare the material resistance against decay fungi and moisture performance of three European reference wood species, i.e., Scots pine sapwood (Pinus sylvestris), Norway spruce (Picea abies), and European beech (Fagus sylvatica). Wood material was collected from 43 locations all over Europe and exposed to brown rot (Rhodonia placenta), white rot (Trametes versicolor) or soft rot fungi. In addition, five different moisture performance characteristics were analyzed. The main results were the two factors accounting for the wetting ability (kwa) and the inherent protective properties of wood (kinh), factors for conversion between Norway spruce vs. Scots pine sapwood or European beech for the three decay types and four moisture tests, and material resistance dose (DRd) per wood species. The data illustrate that the differences between the three European reference wood species were minor, both with regard to decay and moisture performance. The results also highlight the importance of defined boundaries for density and annual ring width when comparing materials within and between experiments. It was concluded that with the factors obtained, existing, and future test data, where only one or two of the mentioned reference species were used, can be transferred to models and prediction tools that use another of the reference species.
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Schilling, Jonathan S., and Jody Jellison. "Oxalate regulation by two brown rot fungi decaying oxalate-amended and non-amended wood." Holzforschung 59, no. 6 (2005): 681–88. http://dx.doi.org/10.1515/hf.2005.109.
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AbstractOxalic acid secretion by brown rot wood-degrading fungi has been proposed to function in pH control and non-enzymatic biodegradation. Although oxalate production in liquid cultures of brown rot fungi commonly correlates with glucose oxidation, excess oxalate accumulation in wood during oxidative decay could impede Fe3+reduction by fungal-derived chelators and thus inhibit brown rot. In this study, we pre-treated spruce wood with various oxalate concentrations and subjected it to brown rot decay byFomitopsis pinicolaandMeruliporiaincrassatain agar- and soil-block trials. In agar-block microcosms containing wood pre-treated with 0, 1, 10 or 100 mM sodium oxalate, test fungi equalized wood oxalate and pH at week 12 of decay by either increasing or reducing wood oxalate, depending on the pre-treatment. Oxalate reductions in wood were not accompanied by increases in agar oxalate. During soil-block decay of wood pre-treated with 0 or 50 mM oxalate, oxalate and pH regulation were time-dependent and more variable. Wood oxalate levels did not increase with increasing fungal biomass (per ergosterol); however, decreases in oxalate were not explained by enhanced oxalate catabolism activity, Ca2+import, or translocation of oxalate into the soil. Our results suggest that brown rot fungi may optimize extracellular oxalate during wood decay, and that soil characteristics may influence this dynamic.
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MOMOHARA, Ikuo, and Koichi YAMAMOTO. "Accelerated laboratory decay test of Japanese cedar treated with LIFETIME wood treatment." Wood Preservation 29, no. 3 (2003): 105–8. http://dx.doi.org/10.5990/jwpa.29.105.
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Marais, Brendan Nicholas, Philip Bester van Niekerk, and Christian Brischke. "Studies into Fungal Decay of Wood in Ground Contact—Part 2: Development of a Dose–Response Model to Predict Decay Rate." Forests 12, no. 6 (2021): 698. http://dx.doi.org/10.3390/f12060698.
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In this article a dose–response model was developed to describe the effect of soil temperature, soil moisture content, and soil water-holding capacity, on the decay of European beech (Fagus sylvatica) wood specimens exposed to soil contact. The developed dose–response model represents a step forward in incorporating soil-level variables into the prediction of wood decay over time. This builds upon prior models such as those developed within the TimberLife software package, but also aligns with similar modeling methodology employed for wood exposed above ground. The model was developed from laboratory data generated from terrestrial microcosm trials which used test specimens of standard dimension, incubated in a range of soil conditions and temperatures, for a maximum period of 16 weeks. Wood mass loss was used as a metric for wood decay. The dose aspect of the developed function modelled wood mass loss in two facets; soil temperature against wood mass loss, and soil water-holding capacity and soil moisture content against wood mass loss. In combination, the two functions describe the wood mass loss as a function of a total daily exposure dose, accumulated over the exposure period. The model was deemed conservative, delivering an overprediction of wood decay, or underprediction of wood service-life, when validated on a similar, but independent dataset (R2 = 0.65). Future works will develop similar models for outdoor, field-trial datasets as a basis for service-life prediction of wooden elements used in soil contact.
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Marfo, Eric D. "Chemical modification of Petersianthus macrocarpus (essia), to determine whether durability depends on bulking or hydroxyl substitution." Journal of Energy and Natural Resource Management 3, no. 3 (2018): 92–96. http://dx.doi.org/10.26796/jenrm.v3i3.64.
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Wood is a biodegradable material. Decay resistance of wood is improved when the wood is chemically modified. The decayresistance of a chemically modified wood is improved as the modification stabilizes the cell wall polymers against enzyme attackdue to the blocking of accessible hydroxyl groups of the cell wall polymers which reduces the amount of water for hydrolysis. Theimproved durability of the modified wood as a result of reducing the amount of water molecules into the cell wall for hydrolysiswill depend on either bulking or percentage hydroxyl substitution (%OH). Petersianthus macrocarpus (essia), a tropical hardwoodspecies was chemically modified with acetic anhydride (AA) and pentanoic anhydride (PA) in dry pyridine to improve its decayresistance. Graveyard test was used to analyze the effect of the modification on the decay resistance of the wood in twelve weeksin-ground contact. Percentage weight loss and visual decay grades were used to evaluate whether the decay resistance dependson weight percentage gain or percentage hydroxyl substitution. The decay resistance of the modified samples were found to bedependent on bulking.
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Brischke, Christian, Christian Robert Welzbacher, and Andreas Otto Rapp. "Detection of fungal decay by high-energy multiple impact (HEMI) testing." Holzforschung 60, no. 2 (2006): 217–22. http://dx.doi.org/10.1515/hf.2006.036.
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Abstract The suitability of a previously described high-energy multiple impact (HEMI) test for the detection of early fungal decay was examined. The HEMI test characterises the treatment severity of thermally modified wood by stressing the treated material by thousands of impacts of pounding steel balls. This method differentiates between heat treatment intensities, which are manifest as structural changes in the wood. Similar changes in wood structure are known for wood decayed by fungi. Pine (Pinus sylvestris L.) decayed by brown rot and beech (Fagus sylvatica L.) decayed by white rot were tested. Mass loss caused by fungal decay and resistance to impact milling (RIM) determined in HEMI tests were found to be highly correlated. Testing of non-degraded pine, beech, and ash (Fraxinus exelsior L.) showed only marginal effects of wood density on RIM. Furthermore, annual ring angles and RIM of spruce (Picea abies Karst.) were not correlated. Accordingly, the detection of RIM reduction in decayed wood is not masked by variations in density and orientation of the annual rings. Previous results showed no adverse effects of weathering on RIM. Thus, the detection of fungal decay with HEMI tests is feasible not only for laboratory purposes, but also for wood in outdoor applications that has already undergone weathering.
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Reis, Alisson Rodrigo Souza, Andrielly Gomes Loch, Simone Maria da Costa Oliveira Moreira, Matheus Da Costa Gondim, Marcio Rogério da Silva, and Patrícia Soares Bilhalva dos Santos. "Natural resistance of wood from three forest species exposed to Pycnoporus sanguineus xylophagous fungus." Advances in Forestry Science 6, no. 4 (2019): 839. http://dx.doi.org/10.34062/afs.v6i4.9492.
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Wood is subject to degradation by biological agents. Therefore, studies are necessary to ensure its appropriate use, avoid economic losses. The objective of this study was to assess the natural resistance of Spanish cedar (Cedrela odorata), yellow ipe (Handroanthus serratifolius) and tauari (Couratari sp.) woods exposed under laboratory conditions to Pycnoporus sanguineus fungus, which causes white rot. The decay test was conducted according to the method defined in the American Society for Testing and Materials, and the intensity of biodeterioration was determined by mass loss of the three test woods and one control wood, pumpwood (Cecropia sp.), which has low natural resistance. Analysis of variance and Tukey’s test (p < 0.05) were used in the analysis of results. The wood species were classified as highly resistant and resistant to P. sanguineus. Yellow ipe was the most resistant species to fungus attack, whereas tauari was the most susceptible.
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Zhao, Xiaoqi, Jie Wang, Lei Wang, Shiming Ren, Zheng Hu, and Yamei Wang. "Preparation and properties of nano-TiO2-Chinese herbal medicine composite wood." BioResources 16, no. 2 (2021): 4252–74. http://dx.doi.org/10.15376/biores.16.2.4252-4274.
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The sol-gel method was used to make nano-TiO2 and five Chinese herbal medicines of Sophora flavescens Alt., Hypericum perforatum L., Cnidium monnieri (L.) Cuss., Kochia scoparia (L.), and Zanthoxylum bungeanum Maxim. to prepare five kinds of nano-TiO2-Chinese herbal medicine composite anti-degradative wood. Populus tomentosa Carr was chosen as the wood sample. Indoor decay resistance test results showed that the resistance to weight gain and decay of nano-TiO2-Chinese herbal medicine composite anti-degradative wood noticeably increased compared with either Chinese herbal medicine modified wood or nano-TiO2 modified wood, reaching a strong decay resistance level. The results of the anti-loss test showed that the magnitude of loss of wood samples treated with nano-TiO2 and Chinese herbal medicine was noticeably reduced compared with that with just Chinese herbal medicine. It was found by scanning electron microscopy that the nano-TiO2 particles and the Chinese herbal medicine enter the wood cell cavity, and the wood vessels and pits were the main permeation channels. Fourier transform infrared analysis results showed that nano-TiO2 could not only enter the wood interior, and associate with wood components through physical adsorption to form hydrogen bonds, but also through the carboxyl groups in cellulose and hemicellulose, or the phenolic hydroxyl group in lignin, forming a coordinated chemical bond to fix it in the wood component.
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Huang, Congxun, Guoqi Xu, Lihai Wang, Ping Zhang, Pengwei Zhao, and Yan Zhong. "Antagonistic Properties and Screening of Bacillus Velezensis Nhw-B72 against Wood Fungal Decay." Forests 12, no. 6 (2021): 785. http://dx.doi.org/10.3390/f12060785.
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(1) Background: Wood decay is a serious issue that results from the presence of wood-destroying fungi and has a great influence on the international wood industry. The utilization of biological control methods offers good prospects for wood preservation. (2) Methods: The plate-screening experiment, the soil block test of the Chinese stand method (GB/T 13942.1), and the characterization of wood blocks were used to achieve biological control of brown rot and white rot. (3) Results: Through isolation, screening, and identification, the antagonistic bacterium Bacillus velezensis Nhw-B72 strain was obtained. In the plate-screening experiment, the inhibition zone diameter of Nhw-B72 for Gloeophyllum trabeum was 1.68 cm and that for Coriolus versicolor was 2.33 cm. After inhibition, the morphology of mycelia was distorted, malformed, and broken. In the soil block test, the average weight loss percentage of wood blocks in the control group was 61.66%. In the treatment group, the average weight loss percentage of the wood blocks with drying was 28.18% and that of the wood blocks without drying was 34.97%. (4) Conclusions: The strain has an obvious antagonistic effect on the wood-destroying fungi and the sterile fermentative liquid can effectively inhibit wood decay. In addition, compared to the drying of wood blocks, the air-drying of blocks after impregnation with the fermentative liquid had a better inhibition effect.
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Xu, Huadong, Jiedong Wei, Yanan Di, Ruixia Qin, and Zonglin Zhen. "Changes in Carbon Sequestration in Wood During Decay by Brown- and White-Rot Fungi." Journal of Biobased Materials and Bioenergy 14, no. 3 (2020): 414–19. http://dx.doi.org/10.1166/jbmb.2020.1968.
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Wood decay is a releasing process of carbon fixed in the wood. The study on carbon sequestration change caused by decay can provide a theoretical basis for wood preservation and utilization. At present, there are few reports on decay influence on wood carbon emission and no corresponding quantitative data. Therefore, one broad-leaved species, Poplar, and one coniferous species, Korean pine, were selected as the research object, and brown rot fungus (Gloeephyllum trabeum) and white rot fungus (Coriolus versicolor) were used to conduct accelerated decay test on wood samples in the laboratory. During decay, specimens were taken out in different periods to measure chemical properties, mass loss and carbon sequestration. The influence of decay time on carbon sequestration, chemical component and mass loss were then analyzed and the change rule of carbon sequestration were finally studied. The results showed that with increasing decay time, the relative carbon sequestration content of wood affected by different types rot fungi decreased, which was consistent with the change rule of mass loss, indicating that decay would lead to a loss of wood mass and affect its carbon sequestration. However, the absolute carbon sequestration (measured value of carbon sequestration) after brown rot treatment did not decrease but increased slightly, which was different from previous expectation. According to the analysis, with increasing brown rot time, the absolute content and proportion of lignin in wood samples increased slightly, while the corresponding value of holocellulose (including α-cellulose and hemicellulose) decreased significantly. The carbon content of lignin per unit mass is higher than that of holocellulose (Poplar 64.08% > 37.38%; Korean pine 66.37% > 35.94%), resulting in absolute carbon sequestration in wood increases instead of decreases. In conclusion, the change of lignin proportion during the process of brown rot is the decisive factor affecting the change of absolute carbon sequestration. This study focused on two aspects of wood decay and wood carbon sequestration, systematically analyzed the change rule and internal mechanism of wood carbon sequestration with the increase of wood decay degree, and accumulated basic data for wood carbon emission reduction and wood prevention.
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SUZUKI, KENTARO. "Establishment of JIS for "Methods of Test for Woods". Amendment of JIS for "Method of Test for Decay of Wood"." Wood Preservation 20, no. 3 (1994): 136–38. http://dx.doi.org/10.5990/jwpa.20.136.
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Weigenand, Oliver, Miha Humar, Geoffrey Daniel, Holger Militz, and Carsten Mai. "Decay resistance of wood treated with amino-silicone compounds." Holzforschung 62, no. 1 (2008): 112–18. http://dx.doi.org/10.1515/hf.2008.016.
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AbstractAn amino-silicone (AS; amino-polydimethylsiloxane) micro-emulsion was tested for its suitability to preserve wood against basidiomycetes in a mini-block experiment and in a test according to the European standard (1996) EN 113. Decay resistance was assessed against the white rot fungiTrametes versicolor,Ceriporiopsis subvermispora, andHypoxylon fragiforme, as well as the brown rot fungiConiophora puteana,Antrodia vaillantii,Gloeophyllum trabeumandSerpula lacrymans. Pine sapwood and beech wood were treated with AS emulsions at solute concentration levels of 2%, 5% and 15%. The mini-blocks treated with 15% concentrations of AS resisted decay byT. versicolorandC. puteanaover a long time (12 weeks), while samples treated with low and moderate concentrations underwent considerable mass losses. Accordingly, microscopic studies revealed a high degree of colonisation by the white rot fungus and loss of cell wall integrity (brown rot) in samples treated with 2% AS. At high AS content (15%), no or only initial stages of decay could be observed. In the European standard (1996) test EN 113, the mass loss in all fungal cultures except for the white rot ascomyceteH. fragiformewas below 5%, when the samples were treated with 15% AS. The effect of low and moderate AS concentration on the decay resistance was dependent on the fungal strain. The mode of action of AS treatment against basidiomycete decay is discussed.
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Kirker, Grant T., A. B. Bishell, Patricia K. Lebow, and Carol A. Clausen. "Effect of fungal competition on decay rates in bicultured soil bottle assays." Holzforschung 70, no. 6 (2016): 585–91. http://dx.doi.org/10.1515/hf-2015-0115.
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Abstract For decades, wood scientists and preservative formulators have employed the monocultured soil bottle assay to test efficacy of wood treatment in the laboratory as a rapid predictor of field performance. This study examines the effects of bicultured soil bottle assays on the decay by common wood decay fungi. Mycelial interactions were noted in early stages of colonization. With only two exceptions, a single fungus was apparent in each soil bottle, indicating dominance. The dominant fungi were not always the most efficient wood rots, and the rot type, white or brown, did not affect the dominance outcome on the preferred wood type.
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Furuno, Takeshi, Fuyuki Wada, and Sulaeman Yusuf. "Biological resistance of wood treated with zinc and copper metaborates." Holzforschung 60, no. 1 (2006): 104–9. http://dx.doi.org/10.1515/hf.2006.018.
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Abstract Insoluble metaborates were formed by impregnating wood with borax and metallic salts, and the biological resistance of samples treated with metaborates was evaluated. The double-diffusion process was carried out to form metaborate precipitates in sapwood specimens of Japanese cedar (Cryptomeria japonica). Water-saturated wood specimens were first impregnated by a saturated borax solution and then diffusion-penetrated with solutions of zinc sulfate or copper sulfate of different concentrations. In laboratory-scale termite tests of wood specimens treated with zinc and copper metaborates at five concentrations from 3% to 20% using a virulent subterranean termite (Coptotermes formosanus), metaborate-treated wood showed negligible weight loss, with high termite mortality at the lowest concentration of 3%. An additional termite test for treatments at lower concentrations of 1% and 2% revealed good termite resistance even with small weight gains of 2.3–6.7%. In field termite tests using a tropical dominant termite (Macrotermes gilvus) in Serpong, Indonesia, wood specimens of 2 cm (r)×2 cm (t)×10 cm (l) treated with metaborates at 5% and 20% showed little weight loss against termite attack for 2 months or more. In addition, in a decay test using a white-rot fungus (Trametes versicolor) and a brown-rot fungus (Fomitopsis palustris), metaborate-treated woods showed enhanced decay resistance. This superb enhancement of biological resistance against termite and decay attacks is considered to be attributable to the presence of metaborates containing effective components such as boron, zinc or copper in the cell walls, which were detected by EPMA observations.
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Lin, Liang, Takeshi Furuno, and Sadanobu Katoh. "Leachability and Decay Resistance of Tetraphenylborate Salt-Treated Wood." Holzforschung 55, no. 4 (2001): 355–57. http://dx.doi.org/10.1515/hf.2001.059.
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Summary In order to reduce the leachability of boron compounds in wood, the double treatment of tetraphenylborate sodium salt [(C6H5)4BNa] (TPBNa) with potassium chloride (KCl) or tetramethylammonium bromide [(CH3)4NBr] (TMABr) was investigated by impregnating them into sapwood specimens of Japanese cedar (Cryptomeria japonica) to form insoluble salts of tetraphenylborate tetramethylammonium or tetraphenylborate potassium. The reduction of boron retention in treated wood specimens after the waterleaching test was very small, showing the good fixation of boron compounds in wood. The double treatment of TPBNa salts with TMABr or KCl solution also showed an excellent decay-resisting effect against both Coriolus versicolor and Tyromyces palustris at low boron retention.
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da Silveira, Marcelo F., Fernando N. Gouveia, Alessandro C. O. Moreira, et al. "Natural resistance of eight Brazilian wood species from the region Caatinga determined by an accelerated laboratory decay test against four fungi." Holzforschung 73, no. 2 (2019): 151–54. http://dx.doi.org/10.1515/hf-2018-0051.
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AbstractNatural resistance of eight wood species from Caatinga, an exclusive Brazilian biome, was evaluated according to [ASTM Standard (2005) D 2017-05. Standard test method of accelerated laboratory test of natural decay resistance of woods.]. Samples were exposed to white rot (WR) and brown rot (BR) fungi, namely toTrametes versicolor(WR),Pycnoporus sanguineus(WR), Gloeophyllum trabeum(BR) andGloeophyllum striatum(BR). Weight loss, specific gravity and extractive content of each wood species were evaluated.Diptychandra aurantiaca,Pterodon abruptusandTerminalia fagifoliawere classified as “highly resistant”, whileT. fagifoliawas “resistant” toT. versicoloronly.Machaerium acutifoliumwas resistant to all fungi.Aspidosperma multiflorumwas resistant to WR fungi andCombretum glaucocarpumto a BR fungus. The speciesPityrocarpa moniliformisandSwartzia psilonemawere moderately resistant.
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Lu, Jinrong, Martti Venäläinen, Riitta Julkunen-Tiitto, and Anni M. Harju. "Stilbene impregnation retards brown-rot decay of Scots pine sapwood." Holzforschung 70, no. 3 (2016): 261–66. http://dx.doi.org/10.1515/hf-2014-0251.
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Abstract Stilbenes are abundant in the heartwood of Scots pine (Pinus sylvestris L.) and are known to have strong antifungal efficiency. In this study, Scots pine sapwood blocks were impregnated with crude heartwood extract containing the stilbenes pinosylvin (PS) and the pinosylvin monomethyl ether (PSM). Impregnated blocks were submitted to brown-rot fungi, Coniophora puteana, Gloeophyllum trabeum, and Rhodonia (Poria) placenta, and fungal growth test and decay test were performed. Both tests showed that the impregnation with a high concentration of stilbenes (60 mg g-1 dry wood) significantly suppressed the growth of fungi and slowed down the decay process of wood blocks, especially in case of G. trabeum. However, chemical analysis showed that PS and PSM were degraded by all the three types of fungi, obviously via modification to resveratrol and methylresveratrol. Rhodonia placenta displayed the fastest rate of degradation. Thus, impregnation with biodegradable stilbenes could be a viable alternative for wood preservation only in service situations with low or transient risk of decay.
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Larjavaara, Markku, and Helene C. Muller-Landau. "Comparison of decay classification, knife test, and two penetrometers for estimating wood density of coarse woody debris." Canadian Journal of Forest Research 40, no. 12 (2010): 2313–21. http://dx.doi.org/10.1139/x10-170.
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Inventories of the necromass of coarse woody debris typically involve measurements of density (e.g., kilograms per cubic metre) on a sample of logs, with densities of other logs estimated based on assignment to decay classes. Here, we compare two new devices for assessing density of woody debris, a spring penetrometer and a dynamic penetrometer, with the traditional decay classification and knife test in terms of the strength of the relationship with measured density and the consistency in measurements by four different people. Our evaluation was conducted in a diverse tropical forest and involved only a brief training period in each method. Classifications or scores from all four methods were only weakly correlated with measured density, and consistency among technicians in the measurement–density relationship was highest for the dynamic penetrometer. Therefore, we conclude that when training time is limited and the sampled logs can reasonably be assumed to be representative of all of the logs (e.g., an inventory of one site at one time), it is best to simply assume that the average density of the sampled logs is representative of nonsampled logs. For inventories involving multiple people, limited training, and cases where the sample average is likely to be unrepresentative, we recommend the dynamic penetrometer.
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Ohno, Katie M., Amy B. Bishell, and Glen R. Stanosz. "Differential Expression of a Putative Copper Homeostasis CutC Gene in Fibroporia radiculosa During Initial Decay of Copper-Treated Wood." Forest Products Journal 70, no. 4 (2020): 469–75. http://dx.doi.org/10.13073/fpj-d-20-00043.
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Abstract Living organisms require copper for several cellular processes. Yet intracellular concentrations of copper must be regulated to avoid toxicity. Not much is known about mechanisms of copper regulation in wood decay fungi. However, one putative annotation for a copper homeostasis CutC gene (FIBRA_00129), found in other brown-rot wood decay fungi, has been annotated in Fibroporia radiculosa. The aim of this study was to evaluate wood mass loss and differential expression of FIBRA_00129 during initial decay of untreated and copper-treated wood by two copper-tolerant F. radiculosa isolates (FP-90848-T and L-9414-SP) compared with copper-sensitive Gloeophyllum trabeum. Untreated southern pine (Pinus spp.) and ammoniacal copper citrate treated southern pine at three concentrations (0.6%, 1.2%, and 2.4%) were used in a 4-week-long standard decay test. Results showed G. trabeum was unable to decay copper-treated wood while both F. radiculosa isolates successfully decayed southern pine at all copper concentrations. G. trabeum and F. radiculosa L-9414-SP showed no detectable FIBRA_00129 expression over the course of this study. F. radiculosa FP-90848-T showed greater FIBRA_00129 downregulation on copper-treated wood than on untreated wood (P = 0.003). Additionally, there was greater FIBRA_00129 downregulation in F. radiculosa FP-90848-T at week 3 compared with other weeks (P = 0.015). Future studies are needed to further evaluate FIBRA_00129 during the decay process to determine its potential role in copper-tolerance.
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Hope, S. M. "Classification of decayed Abiesamabilis logs." Canadian Journal of Forest Research 17, no. 6 (1987): 559–64. http://dx.doi.org/10.1139/x87-093.
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Pacific silver fir (Abiesamabilis (Dougl.) Forbes) fallen logs near Snoqualmie Pass, Washington, U.S.A., were classified according to visual, chemical, and physical characteristics. The purpose of the study was (i) to test differences in log classification according to three- and five-unit decay classes, and (ii) to determine which variables appeared to be successful descriptors of decay for Pacific silver fir. Discriminant analysis was used to select variables to describe decay levels. According to analyses, wood density and lignin and cellulose percentages were acceptable criteria for describing decay levels using either a three- or five-unit classification system. Using a three-unit system defined by field characteristics and laboratory measures, cellulose discriminated among the classes 67% of the time. The variable wood density could be successfully classified 60% of the time. With a five-unit decay class system, individual variables placed logs within classes with less than 50% accuracy. Combinations of variables such as cellulose, wood density, and wood failure level improved class discrimination. Combined field measures were less successful in discriminating decay classes than variables measured under laboratory conditions. Results showed that (i) selection of structural characteristics can change the allocation of logs to particular classes, and (ii) three decay classes could be defined more clearly than five decay classes.
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VenälÄinen, M., A. M. Harju, T. Nikkanen, L. Paajanen, P. Velling, and H. Viitanen. "Genetic Variation in the Decay Resistance of Siberian Larch (Larix sibirica Ledeb.) Wood." Holzforschung 55, no. 1 (2001): 1–6. http://dx.doi.org/10.1515/hf.2001.001.
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Summary The aim of the study was to estimate the degree of genetic determination in the decay resistance of Siberian larch (Larix sibirica Ledeb.) wood and its correlation to other wood traits. The wood samples were taken from 25-year-old grafted seed orchard clones with an increment core borer, dried, weighed, and subjected to a laboratory decay test using a modified method based on the standardised EN 113 method. One brown rot fungus, Coniophora puteana (Schum. ex Fr.) Karst., was used as the decaying organism. The advantages of the method were the savings in time, the possibility to study standing trees, and the potential for screening large numbers of samples at reasonable costs. The clonal repeatability was used to estimate the degree of genetic determination. The genetic determination appeared to be stronger for decay resistance than for growth characteristics or heartwood formation, but weaker than for wood density or latewood formation. Decay resistance and the growth characteristics did not correlate.
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Moya, Roger, Johanna Gaitán-Álvarez, Alexander Berrocal, and Fabio Araya. "Effect of CaCO3 on the wood properties of tropical hardwood species from fast-growth plantation in Costa Rica." BioResources 15, no. 3 (2020): 4802–22. http://dx.doi.org/10.15376/biores.15.3.4802-4822.
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This work aimed to evaluate the effect of the precipitation of CaCO3 via subsequential in-situ mineral formation based on a solution-exchange process of two solution-exchange cycles via impregnation with CaCl2 in ethanol and NaHCO3 in water. The effects were investigated in terms of the structure of the wood and the thermal, physical, mechanical, and decay resistance properties of nine species commonly used in commercial reforestation in Costa Rica. The thermogravimetric analysis results showed that the woods with the highest formation of CaCO3 showed a more pronounced signal at 200 °C in relation to untreated/wood; therefore, they were more thermostable. The fire-retardancy test showed that flame time in CaCO3/wood composites was longer than for untreated/wood in half of the species tested, presenting a positive effect of mineralization. Wood density, decay resistance, modulus of rupture (MOR), modulus of elasticity (MOE) in flexion, and MOR in compression were slightly affected by mineralization. Water absorption increased, but it had no negative effect on the dimensional stability. In general, mineralization can be a chemical treatment to increase the dimensional stability and fire resistance of hardwood species without modifying the wood’s physical and mechanical properties.
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Steenkjær Hastrup, Anne Christine, Bo Jensen, Carol Clausen, and Frederick Green III. "The effect of CaCl2 on growth rate, wood decay and oxalic acid accumulation in Serpula lacrymans and related brown-rot fungi." Holzforschung 60, no. 3 (2006): 339–45. http://dx.doi.org/10.1515/hf.2006.054.
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AbstractThe dry rot fungus,Serpula lacrymans, is one of the most destructive copper-tolerant fungi causing timber decay in buildings in temperate regions. Calcium and oxalic acid have been shown to play important roles in the mechanism of wood decay. The effect of calcium on growth and decay was evaluated for 12 strains ofS. lacrymansand compared to five brown-rot fungi. This was done by treating copper citrate (CC)-treated Southern yellow pine (SYP) wood with a CaCl2solution and estimating the decay rate and amount of soluble oxalic acid in an ASTM soil block test. Decay byS. lacrymanswas found to be significantly inhibited by treatment with CaCl2in the presence of copper. In addition, calcium showed no effect on two strains ofS. lacrymansand oneSerpula himantioidesstrain in non-copper-treated SYP wood blocks. The growth rate ofS. lacrymanswas not affected on malt extract agar containing CaCl2. In summary, a marked decrease was observed in the decay capacity ofS. lacrymansin pine treated with CC+CaCl2. The amount of soluble oxalic acid was measured in CC-treated blocks and blocks also treated with CaCl2. Of the comparative brown-rot fungi, bothAntrodia vaillantii(TFFH 294) andPostia placenta(Mad 698) displayed notable wood decay despite CaCl2treatment, while the remaining strains were inhibited.
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Zaremski, Alba, Marc Ducousso, Odile Domergue, et al. "In situ molecular detection of some white-rot and brown-rot basidiomycetes infecting temperate and tropical woods." Canadian Journal of Forest Research 35, no. 5 (2005): 1256–60. http://dx.doi.org/10.1139/x05-056.
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Wood-decay white-rot and brown-rot fungi have a major economic impact on commercial and manufactured tropical and temperate woods. The aim of this study was to design a molecular method, coupled with polymerase chain reaction (PCR) and DNA sequencing, to enable early identification of various forms of fungal decay in various types of wood. The resulting tool could be used to certify the healthiness of commercial woods and also to make more efficient use of chemicals and thus reduce their negative environmental impact. Sapwood plates of Distemonanthus benthamianus,Fagus sylvatica, Lophira alata, Pinus sylvestris, and Pycnanthus angolensis were incubated in vitro in the presence of Fibroporia vaillantii, Coniophora puteana, Gloeophyllum trabeum, Pycnoporus sanguineus, and Trametes versicolor according to the EN 113 standard method. Average mass losses ranging from 2.6% to 25.0% indicated that all wood samples had been actually infected and enabled us to test the reliability of our method. PCR products were obtained in 24 of 25 combinations, and DNA sequences were obtained in 21 of the 24 fungal PCR products. DNA sequences obtained from infected wood were compared with sequences from pure strains, thus confirming the identity of the infecting strains with 100% similarity for an average of 412 bp.
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Janzen, Steve, and Darrel D. Nicholas. "Relation of transverse compression properties and the degree of brown rot biodeterioration of Pinus glabra in the soil block test." Holzforschung 70, no. 11 (2016): 1067–71. http://dx.doi.org/10.1515/hf-2016-0004.
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Abstract Improved methods are needed for detecting and quantifying the effect of decay fungi on wood products. The focus of the present paper is a soil block decay test with exposure to the brown rot fungus Gloeophyllum trabeum, where the changes in elasticity and strength were compared in both the radial and tangential directions as a function of the decay degree. The stress-strain analysis was employed by a transverse compression (transC) testing technique in which a load was applied over the specimen’s tangential or radial surface. It was found that early effects of decay were detected in either direction of loading, but the overall reduction in elasticity and compression strength after 7 days of exposure to the fungus was approximately two times greater in the radial direction. This difference is interpreted that decay occurs mainly in the earlywood (EW). Significant strength loss at 5% compression was detected after 2 days of exposure to the fungus. However, 3 days of exposure was required before significant strength loss was evident as a result of the reduction in modulus of elasticity (MOE) or mass loss (ML). In comparison to ML, the compression strength loss was found to be a more sensitive measure of wood decay.
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Brischke, Christian, and Andreas Otto Rapp. "Dose–response relationships between wood moisture content, wood temperature and fungal decay determined for 23 European field test sites." Wood Science and Technology 42, no. 6 (2008): 507–18. http://dx.doi.org/10.1007/s00226-008-0191-8.
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Giuriani, Ezio, Alessandra Marini, Stefania Cominelli, and Alessandra Gubana. "The Penetration Test to Evaluate Wood Decay after 20 Years Timber Structure Assessment Experience." Advanced Materials Research 778 (September 2013): 201–8. http://dx.doi.org/10.4028/www.scientific.net/amr.778.201.
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The Wood Penetration Test described in the present paper was set up almost 20 years ago to evaluate the timber vaulted roof decay of Palazzo della Loggia in Brescia (Italy). The test can be regarded as an extension to timber structures of the dynamic soil penetration test, as it is based on the insertion into timber structural members of a steel graduated rod, which advances by means of repeated constant energy blows transmitted by a rebound hammer. The test makes possible to distinguish between different degrees of decay as a function of the number of blows necessary for each centimetre layer penetration. This technique proved to be effective and reliable for investigating the extent and depth of wood decay and thanks to the assessment campaign the possibility of restoring the ancient vault gained strength. The test was then frequently proposed and adopted by the Structural Engineering Laboratory of Brescia University and several ancient building timber structures were checked by means of this methodology. Some significative examples will be briefly described. A recent investigation has been done on the rim beams at the basis of the Palazzo della Loggia timber vault by using the penetration test and the Resistograph and the comparison of the results is also illustrated. The test is easy to perform and the output data can be interpreted very clearly by structural engineers: it is possible to determine the depth of the decayed layers and consequently the reliable dimensions of the resisting timber sections.
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Enukwa, Ettagbor Hans, and Yilom Hyginus Ndang. "EFFECTS OF NEEM OIL ON THE PRESERVATION OF MILICIA EXCELSA: EVALUATION OF TERMITICIDAL EFFECTIVENESS." International Journal of Research -GRANTHAALAYAH 8, no. 12 (2021): 315–22. http://dx.doi.org/10.29121/granthaalayah.v8.i12.2020.2873.
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Wood usage has increased with time, thus, there is need to investigate how wood can be treated with human and environmentally friendly preservative which is effective in protecting wood from termites and other agents of wood deterioration, or improve the wood physical, chemical, mechanical and biological characteristics. The aim of this study was therefore to evaluate the effects of neem oil on Milicia excelsa wood preservation. Treated and untreated pieces of Milicia excelsa wood samples were used to carry out this experiment, a soil bed, and an internal wood exposure to termite’s test was carried out, and measurements taken using a digital weighing machine. The results obtained showed that, when Milicia excelsa is treated with neem oil, its Rate of Decay (ROD) reduces as compared to the untreated pieces. Also, neem oil treated wood when exposed to termite’s attack experiences a slower weight loss compared to untreated samples with significant weight loss. Neem oil is thus not only effective in preserving woods, but also non- toxic to human and the environment.
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Giuriani, E., and A. Gubana. "A penetration test to evaluate wood decay and its application to the Loggia monument." Materials and Structures 26, no. 1 (1993): 8–14. http://dx.doi.org/10.1007/bf02472232.
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Han, So Ra, Chun Young Park, Young Geun Eom, and Jun Jae Lee. "Studies about the Influence Factors on Ultrasonic Velocity of Domestic Red Pine." Key Engineering Materials 321-323 (October 2006): 1177–81. http://dx.doi.org/10.4028/www.scientific.net/kem.321-323.1177.
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This research was carried out to grasp the factors influencing to the ultrasonic velocity to improve the efficiency of the ultrasonic wave test using as the method of NDE of wood. However, it was difficult to detect the defect of wood accurately, because ultrasonic velocity is influenced by various factors. So, some effect factors, which were not concerned with decay, were confirmed at first. Therefore, in this research, we tried to find the factors which affect on the natural characters and the ultrasonic velocity at decayed wood, additionally, we tried an anatomic experiment and analyze. As a result of research, the velocity at radial direction was faster than that at tangential direction and the ultrasonic velocity at immature wood and reaction wood was slower than that at normal wood. And the ultrasonic velocity was more the slower at bigger the length of decay and reduction of weight.
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Son, E., J. J. Kim, Y. W. Lim, T. T. Au-Yeung, C. Y. H. Yang, and C. Breuil. "Diversity and decay ability of basidiomycetes isolated from lodgepole pines killed by the mountain pine beetle." Canadian Journal of Microbiology 57, no. 1 (2011): 33–41. http://dx.doi.org/10.1139/w10-102.
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When lodgepole pines ( Pinus contorta Douglas ex Louden var. latifolia Engelm. ex S. Watson) that are killed by the mountain pine beetle ( Dendroctonus ponderosae ) and its fungal associates are not harvested, fungal decay can affect wood and fibre properties. Ophiostomatoids stain sapwood but do not affect the structural properties of wood. In contrast, white or brown decay basidiomycetes degrade wood. We isolated both staining and decay fungi from 300 lodgepole pine trees killed by mountain pine beetle at green, red, and grey stages at 10 sites across British Columbia. We retained 224 basidiomycete isolates that we classified into 34 species using morphological and physiological characteristics and rDNA large subunit sequences. The number of basidiomycete species varied from 4 to 14 species per site. We assessed the ability of these fungi to degrade both pine sapwood and heartwood using the soil jar decay test. The highest wood mass losses for both sapwood and heartwood were measured for the brown rot species Fomitopsis pinicola and the white rot Metulodontia and Ganoderma species. The sap rot species Trichaptum abietinum was more damaging for sapwood than for heartwood. A number of species caused more than 50% wood mass losses after 12 weeks at room temperature, suggesting that beetle-killed trees can rapidly lose market value due to degradation of wood structural components.
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Li, Yong Feng, Yi Xing Liu, Jiang Tao Shi, and Gang Li. "Structure and Property of PGMA/Wood Composite." Advanced Materials Research 87-88 (December 2009): 456–61. http://dx.doi.org/10.4028/www.scientific.net/amr.87-88.456.
Full textAbstract:
In order to prepare a wood-based composite material which, as a type of multifunctional and natural bio-based material, possesses satisfactory mechanical properties, excellent durability (i.e., decay resistance and dimensional stability), and Aenvironmental characteristic, the study presents a new method which is based on the cellular structure of wood by initiating polymerizable monomers for in situ polymerization. Glycidyl methacrylate (GMA) as a multifunctional and polymerizable monomer was chosen, and impregnated into the porous structure of wood. After a thermal-catalyst process, the wood-based composite, PGMA/Wood, was prepared. The structure of this material was analyzed by SEM, FTIR and XRD; and its performance was also determined. The analyzing results show that GMA not only polymerized in the cellular structure in a solid form and amorphous form, which fully and uniformly filled in wood cell lumen, but also sufficiently grafted onto wood cell walls in a chemical level, resulting in tight contact between wood cell walls and resultant polymers (PGMA) without any obvious cracks. The test results of mechanical properties show that the modulus of rupture (MOR), modulus of elasticity (MOE), compression strength, and hardness of PGMA/Wood increased by 82%, 122%, 139%, and 348% over those of untreated wood, respectively. The test results of durability show that the dimensional stability and decay resistance of PGMA/Wood improved 44% and 91% than those of untreated wood, respectively. Such composite could be widely applied in the fields of construction, furniture and traffic.
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Singh, Tripti, and Dave Page. "Evaluation of Selected Accelerated Above-Ground Durability Testing Methods for Wood after Ten Years Exposure." Forests 11, no. 5 (2020): 559. http://dx.doi.org/10.3390/f11050559.
Full textAbstract:
Traditional benchmark wood durability testing methods such as stake tests take many years to give conclusive results, and in-ground tests do not always indicate the efficacy of preservatives in above-ground situations. To find test methods that would shorten the time required for wood evaluation for above-ground end uses, a series of different types of accelerated durability tests were set up. Five types of test: ground proximity, two types of decking, flat panels and double layer, were reassessed after ten years to determine whether the decay rankings given to the various types of preservative had changed over the extended exposure period. Exposure conditions varied between tests, with ground proximity being close to ground, and the double layer test carried out in very wet conditions, while raised decking and flat panel tests were relatively dry. In all of these tests, the preservative retention was 25% of the normal H3 retention. The results indicated that the ground proximity tests gave the fastest and most reliable results. Flat panels contained the next highest decay rates, followed by ground-level decking, double layer and raised decking. The evaluation and comparison of these five test methods after ten years’ field exposure confirmed the trend and relative decay rate that was observed at four-year exposure. The use of a regression model for prediction showed a statistically significant overall relationship between decay scores in 2011 and 2017 (coefficient = 0.14 ± 0.07, d.f. = 345.7, t = 2.038, p = 0.042). When resistance to decay was compared between preservatives, copper-chrome arsenate (CCA)-treated pine and naturally durable spotted gum samples were in better conditions than pine treated with any of the other preservatives.
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Daniel, Geoffrey, Thomas Nilsson, and Jindrich Volc. "Electron microscopical observations and chemical analyses supporting Mn uptake in white rot degraded Alstonia and pine wood stakes exposed in acid coniferous soil." Canadian Journal of Microbiology 43, no. 7 (1997): 663–71. http://dx.doi.org/10.1139/m97-094.
Full textAbstract:
Brownish-black spots and flecks several millimetres wide were frequently recognized on the surface and within nonpreservative-treated hardwood (Alstonia scholaris (R.Br.)) and softwood (Pinus sylvestris L.) test stakes placed in an acid forest soil. Energy-dispersive X-ray microanalysis in conjunction with transmission electron microscopy (TEM) and gross chemical analysis of wood using inductively coupled plasma spectrometry showed the flecks to be composed primarily of Mn, which was selectively removed from the surrounding soil. A similar uptake of Mn into wood stakes placed in presterilized acid soil was not noted, indicating the process resulted from biotic activity. Detailed TEM observations showed intrusion of Mn into the wood cell lumina and into areas of erosion, cavity formation, and decayed middle lamella in Alstonia and pine wood cells attacked by an unknown white rot decay fungus. Distinct zones of apparent delignification were also noted progressing across secondary cell walls and middle lamella regions of attacked cells, although it was unclear if the effect was caused by nonenzymatic attack by Mn, enzymatic attack by the fungus, or a combination of both. Mn is thought to play a major regulating role in both lignin depolymerization and mineralization in the presence of organic acids during white rot decay. Present observations also suggest that uptake of Mn into wood stakes during microbial degradation results from biotic activity and soil type and pH are of major significance.Key words: Mn, test stakes, electron microscopy, white rot decay, inductively coupled plasma spectrometry.