Your search resulted in 211 documents. Displaying 25 entries per page.
Targeted inhibition of wood decay fungi: degradation of cotton cellulose
1999 - IRG/WP 99-10321
Brown-rot decay is responsible for 80% of the damage and replacement of wood in service. For nearly thirty years, researchers have postulated a one-electron oxidase system combining Fe+2 oxalic acid, and H2O2 in the production of hydroxy radicals which ultimately oxidize cellulose in situ. Recently, researchers have been investigating antioxicants, in combination with biocides (Schultz, et al.,199...
F Green III, T A Kuster
Experiments on the degradation of tributyltin oxide: A progress report
1984 - IRG/WP 3287
A variety of experiments designed to assess the chemical and physical factors affecting the degradation of tributyltin oxide in treated timber are described. Simple procedures in which temperature and oxygen availability were increased in the presence of wood and water suggest that the wood itself was of prime importance. Attempts to decrease degradation with antioxidants were unsuccessful but led...
R J Orsler, G E Holland
Deterioration of wood viewed from iron nail
1991 - IRG/WP 2368
Deterioration of nail was graded by a five - rank numerical - rating. The rating of nail moisture content and decay of wood were inspected in a mortal-wall of 34-year-old house. The wood was mostly in decay, when the rating of the nail was above about 4, and the moisture content was above about 20%. Nailed wood specimens kept in several humidity room of 20°C for 4 years showed that the rating of ...
H Imamura
Soft-rot in Tabebuia sp. wood used in water cooling tower:
identification and degradation capacity of the fungi
1998 - IRG/WP 98-10253
Tabebuia sp. (ipe), a native Brazilian wood, is considered of high natural resistance to decaying fungi, and has been used in harsh environments, as cooling towers. Fifty-one fungi, belonging to mitosporic fungi group (Fungi Imperfecti), were isolated from deteriorated Tabebuia sp. wood samples, collected from the mist eliminator and packing of a cooling tower in operation for about 23 years. The ...
S Brazolin, M Tomazello, I H Schoenlein-Crusius
Residual resistance in eucalypt poles according to the degree of sanity
1984 - IRG/WP 2225
A lot of 50 eucalypt poles presenting external deterioration by fungus was taken from service and tested. These poles were classified into five degrees of sanity according to evaluation criteria adopted by the IPT Wood Division. After being classified, they were tested with respect to their bending resistance, in order to gather information about their critical degree of sanity which may define th...
F C Geraldo, S Milano, S G De Sequeira
Termiticide degradation in Mississippi field tests
1994 - IRG/WP 94-30052
Degradation rates of some currently marketed United States termiticides are currently being studied. Separate quantities of soil were each treated at lowest label rates with termiticide, and placed in trenches along the inside and outside of concrete walls. Composite soil samples, each consisting of four soil cores, were collected after 1, 30, 60, 120, 180, 240, and 365 days, and again at 2 and 3 ...
B M Kard
Application of non-destructive techniques (durometric and ultrasonic) to evaluate the degradation of woods in service by Gloeophyllum trabeum
2001 - IRG/WP 01-20220
In order to establish the degree of degradation of wood used in construction, it is necessary to employ non-destructive methods (ultrasonic, durometric, densitometric). In this study, ultrasonic and Pilodyn durometric techniques have been applied to try to establish parameters of relationship between the values obtained by both, for their immediate application to wood in service. As a method of re...
M T De Troya, L Palaia, A Navarrete, V Galvañ, R Molina, A Guijarro, J Camacho
Ultrastructure of Prumnopitys ferruginea wood from a buried forest in New Zealand
1991 - IRG/WP 1489
The buried wood of Prumnopitys ferruginea, a New Zealand native tree, was examined by scanning and transmission electron microscopy to investigate the extent to which the wood had deteriorated and the cause of its deterioration. Examinations showed that some deterioration of wood had occurred. Microscopy revealed a decay pattern similar to that produced by cavitation bacteria. Lenticular cavities ...
A P Singh, T Nilsson, G F Daniel
Estimation of the impregnation degree of pine wood by the distribution analysis of active ions concentration in the cross-section
1999 - IRG/WP 99-20174
Samples in the form of pine wood rollers of diversified moisture content of ca. 50, 28 and 12% were impregnated with a water solution of the mixture type CCB with the use of the full-cell process. Moisture content was determined in individual layers from the girth to the pith. In the same way the concentrations of copper and chromium ions with the use of the spectrophotometric method and recalcula...
K Lutomski, B Mazela
16S rRNA Analysis of the Bacteria Associated with Biocide Degradation
2004 - IRG/WP 04-10543
The bacterially mediated degradation of the new anti-fungal biocide, bethoxazin, was studied in vitro, by means of 16S rRNA PCR-amplification and cloning techniques. Woodblocks impregnated with a subtoxic concentration of bethoxazin were incubated in compost, and the micro-organisms associated with the wood after 6 and 12 weeks was studied. It was found that after 6 weeks the wood contained a la...
D F Wallace, D J Dickinson
Evidence for actinomycete degradation of wood cell walls
1990 - IRG/WP 1444
Several unique patterns of degradation occurring in wood cell walls have been observed in wooden stakes inserted in unsterile soil in the laboratory. Some of the patterns have also been observed in coniferous wood taken from forest floors. All the observed attack types occur within wood cell walls, mainly within the S2 layer. Attack is characterised by channels of varying diameter or small fusifor...
T Nilsson, G F Daniel, S L Bardage
The influence of staining fungi on the decay resistance of wood treated with alkylammonium compounds
1984 - IRG/WP 3308
Although found to be very effective in laboratory tests, alkylammonium compounds (AAC's) have failed to perform as well in field stake tests. Examination of leachability showed that this was not the cause. The present study investigated the possibility that staining fungi, (which have been observed to rapidly infect the field stakes), degrade the AAC wood preservative. Soil-blocks were tr...
J N R Ruddick
Wood and filter paper degradation, phenol oxidase and one-electron oxidation activities by the white rot fungus Ceriporiopsis subvermispora
2003 - IRG/WP 03-10486
The activities of one-electron oxidation and phenol oxidase during incubation of cultures of the white-rot basidiomycete Ceriporiopsis subvermispora containing either glucose or wood were periodically measured. Further, the degradation activities against wood and filter paper were examined during the course of cultivation. Weight losses of Japanese beech wood and Japanese cedar wood after 12 wee...
H Tanaka, S Itakura, A Enoki
Chemical and biological investigations of double-vacuum treated windows after 5 years in service
1983 - IRG/WP 3219
In 1980 The Swedish Wood Preservation Institute initiated an investigation to study the degradation of TBTO and possible fungal attack in double-vacuum treated window joinery in service during 5 years. A hospital in Gothenburg was chosen that was built during 1969 to 1976. Both untreated and double-vacuum treated windows of Pinus sylvestris were used. A brown alkyl oil type paint (Nordsjö system ...
J Jermer, M-L Edlund, B Henningsson, W Hintze, S V Ohlsson
Immunolocalization of extracellular metabolites from Poria placenta
1988 - IRG/WP 1361
Polyclonal antisera produced to Poria placenta extracellular metabolites was used in immuno-fluoresence microscopy and immuno-gold TEM studies. In the fluorescence work, labelling of Poria placenta hyphae in wet fixed wood material was observed but not in infected wood which was oven dried prior to sectioning and immunolabelling. TEM studies provided better resolution, with gold labelling detected...
B Goodell, G F Daniel, J Jellison, T Nilsson
Degradation of polycyclic aromatic hydrocarbons by laccase
1998 - IRG/WP 98-10267
The degradation of polycyclic aromatic hydrocarbons (PAH) by laccase was investigated. Laccase catalyzed oxidation of phenanthrene, solubilized in the surfactant Tween 20, exhibited an absolute requirement for the mediator compound 1-hydroxybenzotriazole. When Tween 80 was used as the solubilizing agent, the oxidation rates were more than six times higher as compared to Tween 20. Using the thiobar...
S Böhmer, E Srebotnik, K Messner
Field study: Wood degradation pattern in buildings and utility poles in tropical climates of Nigeria
1992 - IRG/WP 92-1521
The paper is the result of five years field study of wood degradation patterns in three ecological forest zones (Guinea Savannah, Tropical rain forest and mangrove forest zones, respectively). It involved 800 residential buildings and 700 electric overhead transmission poles. The methodology used was a modified Eslyn (6) test. A high rate of Ascomycetes and Basidiomycetes attack especially on the ...
E O Onuorah
Fungal detoxification of organotin biocides
1985 - IRG/WP 1258
The ability of a range of wood decaying fungi to inactivate bis(tri-n-butyltin) oxide (TnBTO) in the extracellular growth medium, in stationary liquid culture was determined. A distinction between the ability to tolerate the fungicide and to inactivate it was made: the white-rot organism Coriolus versicolor being the most efficient inactivator. In an attempt to determine the extracellular agents r...
P S Belford, D J Dickinson
Relationship between the bending strength and the degree of termite attacks on western hemlock by Coptotermes formosanus Shiraki
1990 - IRG/WP 1434
For the examination of the relationship between the bending strength and the degree of termite attacks, Western Hemlock (Tsuga heterophylla Sarg.) was used. Sixty specimens (4.5 x 4.5 x 82 cm³) were attacked by termites at the culture room of Coptotermes formosanus Shiraki. The termites were introduced on the central parts (10 cm) of specimens. In the case of the 2 points loading, the bending mom...
K Suzuki, T Tanaka
The relationship between preservative type and surface degrade in Pinus radiata
1980 - IRG/WP 3158
Samples of Pinus radiata D. Don were impregnated with one of two preservative types, a copper chrome arsenic salt and a light organic solvent preservative. The panels were exposed to the weather for 4-5 years at a site near Sydney, Australia. Macroscopic and microscopic examinations showed different rates and patterns of weathering between the samples treated with each preservative and an untreate...
R S Johnstone, R K Bamber
The involvement of extracellular substances for the generation of hydroxyl radical during wood degradation by white-rot fungi
1997 - IRG/WP 97-10218
The activities of one-electron oxidation, hydroxyl radical generation, and phenol oxidase during the incubation of cultures of four white-rot fungi containing either glucose or wood were periodically measured. Further, their degradation activities against wood were examined during the course of cultivation. The generation of hydroxyl radical was correlated to the activity of wood degradation and i...
H Tanaka, S Itakura, A Enoki
Micromorphology of oak wood degraded by brown rot fungus Coniophora puteana
2000 - IRG/WP 00-10356
To characterize the degradation of hardwood by brown rot fungus, Coniophora puteana was incubated on the wood blocks of Quercus accutissima. For comparison, the same fungus was also incubated on the pine wood blocks of Pinus densiflora. In softwood, the shape of the wood cells and thickness of the cell appeared unchanged even the loss of birefringence in the affected areas. In contrast, oak wood d...
Yoon Soo Kim, Seung-Gon Wi, Kwang-Ho Lee
Persistence and residual activity of organophosphorus termiticides in soil and prevention against the degradation of chlorpyrifos
1991 - IRG/WP 1518
The persistence and the residual activity of four comercial organophosphorous termiticides, Chlorpyrifos, Fenitrothion, Tetrachlorvinphos, Pyridaphenthion, in soil were studied under laboratory conditions. The persistence and the residual activity of four organophosphorous termiticides in two types of soil decreased with the lapse of time. These termiticides were mostly degraded by microorganisms ...
T Iijima, M Tanaka, M Higaki
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
Chemical and biological investigations of double-vacuum treated windows after 7½ years in service
1985 - IRG/WP 3339
Earlier investigations of double-vacuum treated windows after five years in service have shown that tributyltin oxide (TBTO) degrades to di- and monobutyltin compounds and that the resistance of the wood against decay decreases. An investigation 2.5 years later of the same windows shows that the degradation of TBTO proceeds fast. After 7.5 years in service only 15-35% of the remaining organotin co...
M-L Edlund, J Jermer, B Henningsson, W Hintze