Your search resulted in 3252 documents. Displaying 25 entries per page.
Biological degradation resistance of wood acetylated with thioacetic acid
1983 - IRG/WP 3223
Chemically, modification of wood is being considered as an alternative to conventional preservation by toxic chemicals. Acetylated wood has been reported to be quite resistant to most biodegrading organisms at weight percent gains (WPG) around 15-19. The conventional acetylation techniques with acethic anhyrdride result in generation of acetic acid. However, acetylation with thioacetic acid overco...
S Kumar, S C Agarwal
Cavitation bacteria
1984 - IRG/WP 1235
A form of bacterial wood degradation is described. The term "cavitation bacteria" has been coined in order to describe the discrete cavities that are formed within the wood cell walls. The bacteria observed within the cavities appeared to be polymorphic with rounded as well as filamentous forms recognised. TEM studies suggest that the bacteria produce diffusable wood-degrading enzymes. Cavitation ...
T Nilsson, A P Singh
The development of soft rot decay in bamboo fibres
1992 - IRG/WP 92-1572
The development of decay by soft rot fungus Chaetomium globosum was investigated in young and mature culms of bamboo Phyllostachys virideglaucescens. Soft rot decay was influenced both quantitatively and qualitatively by the differing levels of lignification in the material. Weight loss was significantly greater in the younger culm compared with the older, more heavily lignified culm. The distribu...
O Sulaiman, R J Murphy
Screening of fungal strains for wood extractive degradation
1998 - IRG/WP 98-10254
Fungal strains were screened for their ability to degrade apolar extractives in wood from scots pine. The degradation of total wood extractives by 91 different strains was monitored in stationary batch assays incubated for 6 weeks. The results obtained show that the ability of wood-inhabiting fungi to utilize wood extractives varied greatly, even for different isolates of the same species. Fungal ...
J Dorado, M J Martinez-Inigo, T A van Beek, F W Claassen, J B P A Wijnberg, R Sierra-Alvarez
Microscopic FT-IR depth profiling study of photo-induced degradation in wood
2001 - IRG/WP 01-20229
FT-IR microspectroscopy was used to monitor the changes in the chemical composition at various depths from the photo-irradiated surface of sugi (Cryptomeria japonica D. Don) sapwood. The radially cut wood face was exposed to artificial solar radiation from a xenon light source at 375 Wm-2 (in a 300 - 700 nm spectral range) for up to 600 h. The IR depth profiling spectra showed that the artificial ...
Y Kataoka, M Kiguchi.
The degradation of wood surfaces by dilute acids
1985 - IRG/WP 3326
Thin radial/longitudinal sections(~100 µ) of Corsican Pine (Pinus nigra) and Lime (Tilia vulgaris), were exposed to Sulphuric, Sulphurous, nitric, acetic, and formic acid at 40°C in the pH range 2-6. After about 3 months exposure to Sulphuric, nitric, acetic and formic acid at pH 2.0 Pine lost some 20-25% of its tensile strength. Losses in tensile strength due to sulphurous acid were greater bei...
P D Evans, W B Banks
Utilisation of carbohydrates by stain fungi in agar culture
1998 - IRG/WP 98-10248
Stain fungi are often defined by their ability to utilise the starch and free sugars found in ray parenchyma cells, and their inability to utilise other wood constituents. However, several species of stain fungi produce bore holes in wood cell walls. This suggests that enzymatic activity capable of degrading structural polysaccharides and/or lignin is associated with the growth of the appressorium...
J Snow, P Vinden, S M Read
Degradation of resin constituents in various wood species by the white rot fungus Bjerkandera sp. strain BOS55
1999 - IRG/WP 99-10301
In previous studies, the white-rot fungus Bjerkandera sp. strain BOS55 was shown to cause extensive degradation of lipophilic extractives (resin) in Scots pine wood. Further research was carried out in order to investigate the ability of Bjerkandera sp. for reducing resinous constituents in various softwood (Douglas fir, larch and spruce) and hardwood species (birch, beech and poplar). The greates...
J Dorado, T A Van Beek, F W Claassen, R Sierra-Alvarez
Effect of fungal degradation on the chemical composition of acetylated beech wood
2003 - IRG/WP 03-40267
This study investigated the impact of fungal attack on the chemical composition of acetylated wood. Beech wood acetylated to different degrees was exposed to decay by the white-rot fungus Trametes versicolor under solid-state fermentation conditions. Laboratory soil-bed assays were also conducted to study the degradation of acetylated wood by soft rot fungi and other soil-inhabiting microorganisms...
H Militz, Dong-won Son, L Gómez-Hernández, R Sierra-Alvarez
Influence of the content of organic matter of soil on the degradation of wood by soft rot fungi
1970 - IRG/WP 27
The degradation of wood specimen burried in the soil by soft rot fungi is influenced by a number of factors. These are in particular the water holding capacity, water content, content of organic matter, pH, content of mineral nutritive substances etc. The results of the interlaboratory tests, carried out within the IRG/WP let presume that the intensity of wood degradation occurs proportionally inv...
O Wälchli
Determination of thermal degradation of isothiazolone treated wood
1997 - IRG/WP 97-30154
Wood treated with 4,5-dichloro-2-n-octyl-4-isothiazolin-3-one was the subject of thermal degradation study. The study included burning isothiazolone treated wood under various temperatures with and without oxygen. The result showed that no harmful combustion products, such as polychlorinated dibenzo-p-dioxins, polychlorinated dibenzo-p-furans and polychlorinated biphenyls, were detected. These fin...
Bing Yu
Immunolabelling studies on the detection of enzymes during the degradation of wood by Phanerochaete chrysosporium
1988 - IRG/WP 1364
The degradation of lignin in native lignocellulosic substrates by white rot fungi is poorly understood. Biochemical studies have shown the involvement of a number extracellular ligninolytic enzymes released by white rot fungi which are capable of the oxidative conversion of DHP's (lignin model compounds) in vitro, but to date conclusive evidence for occurrence of these enzymes in wood und...
G F Daniel, T Nilsson, B Pettersson
Fungal degradation of wood treated with metal-based preservatives. Part 1: Fungal tolerance
1996 - IRG/WP 96-10163
In recent years, concerns have arisen about the leaching of heavy metals from wood treated with chromated copper arsenate (CCA), particularly because of the large amount of CCA treated wood that will be discarded in the coming years. The long term objectives of this work are to determine the fate of copper, chromium and arsenic with the aging and potential decay of CCA-treated wood, and to develop...
B Illman, T L Highley
Inhibition of the biodegradation of coniferous and broadleaved wood by new imidazolium salts
2003 - IRG/WP 03-30320
Studies were carried out on fungicidal values of fourteen potential wood preservatives – modified quaternary heteroaromatic compounds using the screening agar-block. The vacuum treated blocks (22mm x 17mm x 12mm) of Scots pine (Pinus sylvestris L.), spruce (Picea excelsa L.), beech (Fagus silvatica L.) and birch (Betula verrucosa Ehrh.) with testing compounds were exposed to Coniophota puteana a...
J Zabielska-Matejuk, J Pernak, W Wieczorek
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
Fun with Soil Block Jars: Teaching fungal wood decay in the classroom
2006 - IRG/WP 06-10574
In this world of increasing complexity and technological advancements, it is ever more important to raise scientifically literate children. The National Science Foundation Teaching Fellowship Program (NSF GK-12) at the University of Maine provides an opportunity for advanced graduate students in science, mathematics and engineering to bring their knowledge, as well as the latest equipment, to stud...
C Howell, L Gott, B Meehan
Micromorphological Characteristics of Degradation in Bamboo Attacked by White Rot Fungus Lentinus edodes
2006 - IRG/WP 06-10575
In comparison with micromorphological works for wood decay, little known is about the decay pattern of bamboos by wood decay fungi. The present work was undertaken to understand the general degradation pattern of bamboo and the influence of polylaminate layers in bamboo fiber walls on the restriction of fungal decay. The weight loss of bamboo species Phyllostachys puberscens against the white rot ...
Chang Hyun Cho, Kwang Ho Lee, Yoon Soo Kim
Time-of-Flight Secondary Ion Mass Spectrometry Analysis of Polyethylene Glycol Penetration into Wood Cell Walls
2006 - IRG/WP 06-20328
Penetration of high molecular weight polyethylene glycol (PEG) into wood cell walls was investigated in red pine. PEG of different molecular weights (1000, 8000 and 20000) was labelled by bromination and treated samples were analyzed on Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) in dynamic mode. Both negative and positive spectra of the samples were collected in high spatial (bunche...
D Jeremic, P Cooper, P Brodersen
Investigation of new wood preservation formulations based on synergies between antioxidant, 2-HPNO and Propiconazole
2006 - IRG/WP 06-30401
Wood degradation by fungi is a complex phenomenon taking place in part through oxidative reactions involving many oxidizing agents like free radicals and hydroperoxide. In order to develop novel and more environmentally benign preservative systems, mixtures of Propiconazole and antioxidants with different stabilization mechanisms were investigated to detect possible synergies allowing to reduce th...
B Bakhsous, S Dumarçay, E Gelhaye, P Gérardin
Copper borate for the protection of engineered wood products
2006 - IRG/WP 06-40334
Copper borate was evaluated for use in protecting oriented strand board (OSB) from mould, decay, and termites. Aspen OSB bonded with either phenolic or isocyanate resin was treated with several formulations of copper borate at various loadings from 0.26 to 4 percent by weight. These panels were then tested to determine the impact of the preservative on mechanical properties as well as resistance ...
R Smart, W Wall
The Effect of Flavonoids on Colour and Spectral Changes of the Wood Surface Caused by Heat Treatment or Ultra-violet Irradiation
2006 - IRG/WP 06-40341
Both heat treatment and UV irradiation can cause discolouration and change in the spectral properties of wood surface. Some of the characteristic flavonols have significant role on colour and spectral changes, despite of their relative small quantities in wood.
Colour changes and spectral properties of natural and extracted black locust (Robinia pseudoacacia L.) and poplar (Populus nigra L.) were...
R Csonka-Rákosa, L Molnár-Hamvas, E Börcsök, J Molnár, K Németh
Phenol oxidase activity and one-electron oxidation activity in wood degradation by soft-rot deuteromycetes
2007 - IRG/WP 07-10615
Wood degradation, one-electron oxidation activity as assayed by ethylene generation from 2-keto-4-thiomethylbutyric acid (KTBA), and phenol oxidase activity were measured in cultures of six deuteromyce fungi, with glucose or wood as the carbon source. The four fungi that degraded Japanese beech wood had higher one-electron oxidation activities in wood-containing cultures than in glucose-containing...
H Tanaka, M Yamakawa, S Itakura, A Enoki
Gypsum effects on ‘dry rot’ wood degradation as a function of environment
2007 - IRG/WP 07-10624
‘Dry rot’ fungi are a unique group of brown rot fungi that can degrade wood away from ground contact where other fungi fail to colonize. Successfully occupying this niche is partially due to efficient water and nutrient transport, but mobilizing elements, notably calcium (Ca) and iron (Fe), from adjacent building materials has also been implicated in their success. Here we report a series of t...
J Schilling, J Jellison
Photo-degradation of modified and non-modified wood, coated with water borne acrylic coatings during artificial light exposure
2007 - IRG/WP 07-30416
A series of experiments were carried out to investigate photo-degradation of thermally modified (at 210oC and – 0.9 bars for two hours) and non-modified spruce wood (Picea abies L (Karst)), coated with transparent and semitransparent (with 3% pigment content) acrylic coatings during artificial UV light irradiation for 200 hours. Photo-degradation was evaluated in terms of colour changes througho...
M Deka, M Tomažic, M Petric
Comparative study between full cell and passive impregnation method of wood preservation for laser incised Douglas-fir lumber
2007 - IRG/WP 07-40359
Many wood species are highly resistant to conventional pressure treatment. To improve the chemical impregnation into Douglas-fir (Pseudotsuga menziesii Franco) lumber, the passive impregnation method had been developed. In this study, ability of the passive impregnation for lumber was compared with a conventional full cell method. Square Douglas-fir lumber with the incising density of 10,000 holes...
Md N Islam, K Ando, H Yamauchi, Y Kobayashi, N Hattori