Your search resulted in 111 documents. Displaying 25 entries per page.
Immuno-electron microscopic localization of extracellular metabolites in spruce wood decayed by brown-rot fungus Postia placenta
1990 - IRG/WP 1441
Degradation by Postia placenta in spruce and birch wood was shown to occur not only in the wood cell wall but also in the middle lamellae region. Middle lamellae was often found to be degraded along the centerline so that cells could separate along this line. Extracellular membrane structures were found surrounding the hyphae and this matrix labelled positively with antisera produced to Postia pla...
Y S Kim, B Goodell, J Jellison
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
Comparison of cubic and plug samples for preparation and data assembly in permeability study
2000 - IRG/WP 00-20197
In order to determine if plug experimental samples (PES: 30 x 15 mm2 diameter) could be used for inspection of wood permeability characteristics, radial and longitudinal flow directions were prepared according to either PES or cubic experimental samples (CES: 100 x 20 x 20 mm3) from the sapwood zone of Sitka spruce and treated by tanalith-C according to full-cell process. Results from the two prep...
Ultra-structural observations on the degradation of wood surfaces during weathering
1987 - IRG/WP 2280
Radiata pine (Pinus radiata D. Don) sapwood was converted into blocks with a transverse face about 5 mm square and measuring 8 mm longitudinally. Transverse (T.S.), Radial (R.L.S.) and Tangential (T.L.S.) surfaces were prepared and specimens exposed to the weather inclined at 45° facing equatorially for periods of between 20-60 days. After 30 days exposure erosion of the middle lamella was observ...
P D Evans, S Thein
Resistance of Alstonia scholaris vestures to degradation by tunnelling bacteria
1992 - IRG/WP 92-1547
Electron microscopic examination of vessels and fibre-tracheids in the wood of Alstonia scholaris exposed to tunnelling bacteria (TB) in a liquid culture showed degradation of all areas of the secondary wall. The highly lignified middle lamella was also degraded in advanced stages of TB attack. However, vestured pit membranes and vestures appeared to be resistant to degradation by TB even when oth...
A P Singh, T Nilsson, G F Daniel
Cytochemical localization of hydrogen peroxide in brown rot fungus Tyromyces palustris by cerium chloride technique
1999 - IRG/WP 99-10299
Cerium chloride (CeCl3) was used to localize H2O2 cytochemically for studying relationship between ultrastructural and functional characteristics of cellulose degradation by brown rot fungi. This technique proved very useful in localizing discrete electron-densereactionproducts at high resolution with minimal nonspecific deposition. The cytochemical localization of extracellular H2O2 by CeCl3 usin...
Yoon Soo Kim, Seung-Gon Wi
Analysing the characteristic role of moisture content for drying and fluid flow in Sitka spruce. - Part 1: The drying process of sapwood and heartwood of two different thickness of Sitka spruce using a kiln. - Part 2: Effects of moisture content on longitudinal permeability of Sitka spruce in vertical variation of the tree
2000 - IRG/WP 00-40173
The characteristic role of the moisture content in Sitka spruce (Picea sitchensis (Bong.) Carr.) that grown in the United Kingdom was examined by this study on the basis of (1) the reduction of moisture content in two different thickness of sapwood and heartwood by kiln drying process, and (2) the effects of moisture content to the longitudinal void volume filled of tanalith-C by the full-cell pro...
An effective preservative treatment of borak bamboo (Bambusa balcoona Roxb.)
1996 - IRG/WP 96-40070
Adequate penetration and retention of CCA and CCB has been obtained in predried Borak Bamboo (Bambusa balcooa Roxb.), aboundantly grown in Bangladesh, with Full Cell Pressure Process. The treated bamboo can be used as building materials, the sufficient treatability ensured its long term best utilization at ground contact and indoors. Which will keep the environmental & socio economical conditi...
A K Lahiry, S Begum, G N M Ilias, M A Matin Sheikh, M A B Fakir, M I Hossain
Localization of oxalate decarboxylase in the brown-rot fungus Postia placenta
1996 - IRG/WP 96-10161
Oxalate decarboxylase, the enzyme that breaks oxalic acid down into formic acid and carbon dioxide, was recently detected in mycelial extracts of the brown-rot fungus Postia placenta. Differential centrifugation was used to demonstrate that the enzyme is loosely associated with the hyphal surface. Enzyme activity can be removed by washing the hyphae with a low pH buffer. Only low levels of activit...
J A Micales
Water-based water repellents for treatment of wood
1987 - IRG/WP 3446
The water uptake by wood can be reduced by treatment with a water repellent. The water repellents most commonly used are solvent based. In the present work a new type of water repellent that is water-based has been investigated. Two different treatments have shown an effect of the same order as a commercial solvent based product. The cellular distribution of the water repellents has been investiga...
I G Svensson, G Hägglund, I Johansson, W B Banks
The effects of density on vertical variation of permeability of Sitka spruce within tree
2000 - IRG/WP 00-40156
Tree improvement of Sitka spruce is a combination of silviculture and tree breeding aimed at producing higher quality products including increased growth rate and timber yield, and wood density. It is useful to know annual ring structure and density distribution when studying the quality of wood, grading it, or determining how the wood structure affects residual flow in softwoods. Since density is...
Degradation of the normal fibre walls of rubberwood (Hevea brasiliensis) by the tropical blue-stain fungus Botryodiplodia theobromae
1998 - IRG/WP 98-10286
Rubberwood was examined by light microscopy and transmission electron microscopy (TEM) after exposure to the common tropical sapstain fungus Botryodiplodia theobromae for four weeks to study hyphal colonisation of wood cells and to determine if this fungus also degraded lignified normal fibre cell walls in addition to the walls of non-lignified elements. Light microscopy revealed relatively large ...
A A H Wong, A P Singh
TBTO absorption and penetration in pine joinery treated by various processes
1989 - IRG/WP 3523
Matched sections of several White pine (Pinus strobus) and Ponderosa pine (Pinus ponderosa) mouldings were treated with TBTO by Double vacuum, modified empty-cell, 15 second dip and several preheating treatments followed by a 15 s dip treatments. As expected the double vacuum and empty-cell (batch) treatments resulted in much greater retentions and penetrations than the dip treatments. The absorpt...
P A Cooper, Y T Ung
Ultrastructural observations on wood-degrading erosion bacteria
1986 - IRG/WP 1283
G F Daniel, T Nilsson
A behaviour of CCA penetration of fir (Abies bornmulleriana Mattf.) at different ramp times and constant vacuum/pressure applications
2006 - IRG/WP 06-40346
A behaviour of CCA penetration of Bornmulleriana fir (Abies bornmulleriana Mattf.) at different ramp times and constant vacuum/pressure applications was illustrated for the main flow directions by the experimental pictures....
I Usta, R Despot, M Hasan
Ultrastructural aspects of bacterial attacks on an archaeological wood
1993 - IRG/WP 93-10007
Transmission electron microscopy of wood from a Chinese ship submerged in the mud for over 900 years showed bacteria to be the main factor for its deterioration. The micromorphology of degraded wood cell walls was similar to that observed during the attacks of wood by erosion bacteria. Other bacterial forms, previously considered lo be scavenging bacteria, were also abundant in degraded areas of t...
Yoon Soo Kim, A P Singh
The Relationship of Fiber Cell Wall Ultrastructure to Soft Rot Decay in Kempas (Koompassia malaccensis) Heartwoo
2004 - IRG/WP 04-10541
The ultrastructure of fiber walls in kempas (koompassia malaccensis) heartwood was examined in relation to soft rot cavity formation. The fibers consisted of middle lamella and thick secondary wall. The secondary wall was differentiated in to a S1 layer, and a unique multi-lamellar S2 layer. Two distinct forms of lamellae were recognisable, one type being considerably thicker than the other. They ...
A P Singh, A H H Wong, Yoon Soo Kim, Seung-Gon Wi
Leaching of copper, chromium and arsenic from CCA-treated slash pine heartwood
1994 - IRG/WP 94-50020
Drying green slash pine with any of three high temperature drying schedules produced a product in which both the sapwood and the heartwood could be penetrated with CCA using a modified Bethell treatment schedule. Required H3 retentions were achieved in both sapwood and heartwood, from 200 litres per m³ charge uptake. Post-treatment fixation/drying was accomplished by three different regimes, incl...
M J Kennedy, G Palmer
Estimation of effective diffusion path lengths in wood by swelling studies
1989 - IRG/WP 3524
The effective average distance that a solute must diffuse to penetrate the cell wall matrix following pressure treatment is estimated from the rate of swelling of wood, vacuum treated with water. It is assumed that the diffusion paths are similar for water and a solute such as a wood preservative component. Since bound water diffusion coefficients for water in wood have been estimated by others, t...
P A Cooper, R Churma
The attack of naturally durable and creosote treated timbers by Limnoria tripunctata Menzies
1995 - IRG/WP 95-10132
Limnoria tripunctata was found tunnelling in creosote treated Douglas fir (Pseudotsuga menziesii) pilings and naturally durable greenheart (Ocotea rodiaei) gate seals at two sites on the south coast of the United Kingdom. Examination of thc creosote-treated wood showed that Limnoria tunnels were concentrated at a depth of 2-3 cm from the timber surface, where creosote loading was lower. Fewer tunn...
A J Pitman, G S Sawyer, G F Daniel
Role of cell wall structure in soft rot decay of bamboo
1995 - IRG/WP 95-10133
Models of soft rot hyphal penetration of bamboo cell walls are proposed. Soft rot hyphae show an interesting capability of penetrating the bamboo cell wall in different forms; typical longitudinal penetrating hyphae and tangentially orientated penetrating hyphae. The second form of penetration was found to be different from that normally associated with wood cell walls. The differences can be attr...
O Sulaiman, R J Murphy
Ultrastructure of degraded, CCA-treated Pinus radiata wood from a marine pile
1990 - IRG/WP 1461
During an inspection of marine piles, 12 years after installation, severe degradation was noted on one of them in the vicinity of a corroded eye-bolt. The wood was dark brown in colour and tended to crumble easily. Wood fragments were examined by light microscopy and scanning and transmission electron microscopy and were also analysed for carbohydrates and lignin. Light microscopy showed numerous ...
A P Singh, M E Hedley
Degradation of the gelatinous-layer in aspen and rubber wood by the blue stain fungus Lasiodiplodia theobromae
1996 - IRG/WP 96-10168
Studies on the degradative ability of the blue stain fungus Lasiodiplodia theobromae Pat. have shown several strains to cause significant weight losses (i.e. ca 20%) in the temperate and tropical wood species, aspen (Populus tremula) and rubber wood (Hevea brasiliensis). In addition to the consumption of soluble carbohydrates and extractives, major changes in the ultrastructure of fibre cell walls...
O Encinas, G F Daniel
EELS (Electron Energy Loss Spectroscopy) - a technique for quantification of nitrogen and other light elements in the cell wall
1999 - IRG/WP 99-20163
A literature survey was performed to find progress in techniques for monitoring penetration of synthetic resins in wood cell walls. Electron energy loss spectroscopy (EELS) in combination with transmission electron microscopy (TEM) was successfully applied for the high resolution examination of the distribution of a partly methylated hydroxymethyl melamine resin in Norway spruce (Picea abies Karst...
A O Rapp, H Bestgen, W Adam, R-D Peek
Preservation of two Indonesian timber species for marine environment purposes
1994 - IRG/WP 94-10079
This paper deal with the experiment of CCA full cell processed two non-durable Indonesian species for placed in the marine environment. 80 samples of 5 x 5 x 60 cm³ dried durian (Durio zibethinus) and mahogany (Swietenia mahagony) timber were CCA-full cell processed using 4 combination treatment of: without steaming; one hour steaming; 3% and 5% CCA solution concentration. 40 samples of them were...
P Permadi, I M Padlinurjaji, F Rasmita