Your search resulted in 303 documents. Displaying 25 entries per page.
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
Genetic Engineering in tree breeding
1998 - IRG/WP 98-10294
The genetic improvement of forest trees by classical breeding is a slow process in comparison with that of annual crops. Tree breeding however is of great importance and has led to trees with better growth characteristics and better disease resistance. An important wood characteristic which has been neglected in breeding programs is wood durability. The durability of the wood will determine for wh...
J Van Doorsselaere, H Beeckman, M Van Montagu, W Boerjan
Extracellular osmiophilic particles in connection with brown rot and white rot
1982 - IRG/WP 1157
The way of attack on Pine woodblocks of two brown-rot fungi (Fomitopsis pinicola, Coniophora puteana) differing in their cellulase activities, and one white-rot fungus (Trametes hirsuta) has been investigated by transmission electron microscopy. Even at early stages of decay, osmiophilic particles were found with all the fungi investigated. In the brown-rotted wood, the osmiophilic particles occur...
K Messner, H Stachelberger
Comments on soft rot attack in timbers treated with CCA preservatives: A document for discussion
1982 - IRG/WP 1167
This paper is not based on any particular results but rather on several observations of soft-rot during many years of studies, and on a review of the existing literature. The short time available has unfortunately not permitted a detailed review of the literature. Data and knowledge of important facts are lacking for several aspects of soft-rot attack and for reactions occurring in the wood as a r...
T Nilsson
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
Surface characteristics of wood treated with various AAC, ACQ and CCA formulations after weathering
1991 - IRG/WP 2369
Wood samples treated with various alkylammonium compounds (AACs) as well as ammoniacal copper quat (ACQ) and chromated copper arsenate (CCA) have been studied in accelerated weathering experiments. Microscopic examination of the surfaces of these samples after exposure in a weatherometer revealed several different changes. Samples treated with didecyldimethyl ammonium chloride (DDAC) show consider...
L Jin, K J Archer, A F Preston
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
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
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.
Surface protection of wood with titanium, zirconium and manganese compounds
2005 - IRG/WP 05-30376
Thin radiata pine veneers were treated with a range of titanium, zirconium and manganese compounds and exposed to natural weathering. Veneer weight and tensile strength losses were used to assess the protective efficacy of the compounds. The oxidative manganese compounds potassium permanganate and manganic acetate restricted both weight and tensile strength loss of treated wood veneers during weat...
K J Schmalzl, P D Evans
Bacterial degradation of wood cell wall: A review of degradation patterns
1990 - IRG/WP 1460
Information from bacterial degradation studies of 60's and 70's was reviewed by Nilsson in 1982. The application of electron microscopy to this area in recent years has provided much useful information and has eliminated earlier scepticism among workers about the ability of bacteria to degrade lignified wood cell walls. Studies using transmission electron microscopy together with...
A P Singh, J A Butcher
Micromorphological and chemical changes of archaeological woods from wrecked ship's timbers
1987 - IRG/WP 4136
Micromorphological and chemical alterations of sea-waterlogged woods obtained from the ship-wrecked materials which had been submerged in Yellow Sea for over 700 years were investigated. The woods were deteriorated in varying degrees by marine organisms depending on species and parts of the woods. Under the light and scanning electron microscope the morphological characteristics of deteriorated wo...
Y S Kim
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
FTIR studies on the weathering of didecyldimethylammonium compound (DDAC) treated wood
1993 - IRG/WP 93-30013
Wood treated with alkylammonium compounds (AACs), such as DDAC, weathered more rapidly than untreated wood. In order to examine the influence of DDAC treatment of wood on its weathering, treated and untreated microtomed sections of southern yellow pine earlywood of various thicknesses, were prepared and weathered for approximately one month. The changes in these samples were monitored using FTIR. ...
R Liu, J N R Ruddick
Protection of cellulose string with biocide/water repellent mixtures
1997 - IRG/WP 97-30148
Protecting cellulosic materials in soil contact poses a formidable challenge. Many soil inhabiting bacteria and fungi that cannot degrade wood can nevertheless rapidly depolymerize cellulose once its protective lignin matrix is removed. As a result, cellulose based materials are rarely used in direct contact with soil. One exception, however, is the use of cellulose string to support climbing vine...
A B Chang, J J Morrell
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
The action of siderophores isolated from Gloeophyllum trabeum on the structure and crystallinity of cellulose compounds
1991 - IRG/WP 1479
Low molecular weight, high affinity iron-binding compounds (siderophores) were isolated from the brown-rot fungus Gloeophyllum trabeum. The compounds were shown to be inducible by iron starvation and could be purified by ultra-filtration, ethyl acetate extraction, column chromatography and preparative HPLC. The isolated compounds were shown by analytical and immunological techniques to be produced...
J Jellison, V Chandhoke, B Goodell, F Fekete, N Hayashi, M Ishihara, K Yamamoto
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
Degradation of woods by obligately anaerobic fungi
1990 - IRG/WP 1452
Little is known about the processes occurring during the degradation of wood by obligately anaerobic fungi. When woods from a range of hardwood species were incubated for 11 days with a strain of the Chytrid Neocallimastix frontalis many of the woods were measurably fermented; Fagus sylvatica (23%) was the most highly degraded. Microscopic examination of Populus tremuloides wood after incubation w...
K N Joblin, G E Naylor
A substantively bonded water repellent treatment based on chromium carboxylates
1985 - IRG/WP 3344
Chromium carboxylates soluble in toluene have been synthesised and applied to Scots pine (Pinus sylvestris) sapwood. Without any further treatment, the compounds may be readily leached from wood surfaces with toluene. After a period of heating however, they become fixed to the cell wall, substantial amounts being resistant to leaching even under reflux conditions for several hours. Treatment of wo...
J K Wright, W B Banks, W J Eilbeck