Your search resulted in 223 documents. Displaying 25 entries per page.
Formation of soft rot cavities in relation to concentric layers in wood fibre walls
1983 - IRG/WP 1185
A large number of timber species attacked by soft rot have been examined using light microscopy. The S2 layers in a large number of the timbers exhibited special structural features in the form of thin concentric layers. Several observations indicate that these layers may be characterised as "weak" zones by being more easily degradable than the surrounding wall layers. The chemical structure of th...
T Nilsson, G F Daniel
Effects of surfactants and ultrasonic energy on the treatment of wood with chromated copper arsenate
1977 - IRG/WP 3108
Sugar pine stakes 1'' x 1" x 16" were treated by a hot-water bath followed by soaking in cold CCA solution for 10 to 30 minutes. A similar number of stakes were treated by a cold-cold bath. Half of the stakes were subjected to ultrasonic energy during the CCA bath. The mean absorption for stakes given the hot-cold bath was 18.52 pcf (297 kg/m³) and 4.64 pcf (74 kg/m³) for those...
C S Walters
Internal pressure monitoring during the treatment of Pinus radiata (D. Don)
1995 - IRG/WP 95-40049
The use of micro-transducers to monitor the internal pressure of wood during treatment is investigated. The rates of pressure transfer in radiata pine sapwood and heartwood are compared during Bethell treatment with copper chrome and arsenic preservative. The effect of pre-conditioning treatments are also evaluated using micro-transducer monitoring. It is anticipated that knowledge of the changes ...
P R S Cobham, P Vinden
Molecular analysis of the basidiomycete Coniophora puteana
1992 - IRG/WP 92-1534
Sodium dodecylsulphate polyacrylamide gel electrophoresis and Western Blotting, using a polyclonal antiserum produced against a whole cell extract of Coniophora puteana, were used to analyse the major proteins and antigens of the wet rot organism Coniophora puteana. The macromolecule profiles of this organism were different from other members of the Coniophora genus and from a set of unrelated org...
H E McDowell, D Button, J W Palfreyman
Changes in pore structure and cell wall volume in wood decayed by brown- and white-rot fungi
1991 - IRG/WP 1501
Sweetgum (Liquidambar styraciflua L.) wood blocks were decayed by Postia (=Poria) placenta or Phanerochaete chrysosporium in soil-block cultures. Decay was terminated at various weight losses, and the pore volumes available to probes of various molecular weight and diameter were determined by the solute exclusion technique (Stone, J.E. and A.M. Scallan. 1968. Cellulose Chem. Technol. 2, 343-358.)....
D S Flournoy
Soft rot decay of Belian (Eusideroxylon zwageri) wood
1995 - IRG/WP 95-10119
The heartwood of Belian (Eusideroxylon zwageri), an East Malaysian timber species, is naturally durable due to its certain unique anatomical features and high content of extractives. The timber can tolerate years of exposure to hazardous conditions in ground contact and other situations without any significant loss in its strength. A few Belian transmission poles sampled from one locality in Saraw...
A H H Wong, A P Singh
Modified Wood – Methods, testing and applications: Outcomes of the EU-Thematic Network
2003 - IRG/WP 03-40268
In the last decade, interest in the development of wood modification systems has increased in Europe. Alongside several industrial initiatives for heat treatments, there have also been scaling up and pilot plant projects for chemical wood modification. Between 2000 and 2003, the European Commission funded the "Thematic Network on Wood Modification". This paper will feature the modification process...
D Jones, W Homan, J Van Acker
Selective chromate elimination from the storage-drainage-water of a wood impregnation plant
1980 - IRG/WP 3153
With the Enviro-Chrom-Ex process it is possible to eliminate ecologically and economically hexavalent chromium (chromate) from water selectively. The process which is based on the principle of selective ion exchange works with different chromate concentrations and under the presence of other ions, irrespective of the water hardness. The values of water-offtake reach 0.1 mg CrVI at maximum, causing...
O Wälchli, R Ott, R Hugener, E Graf, B Lieberherr
Microbial decay of an archaeological wood
1994 - IRG/WP 94-10053
A light and transmission electron microscopic investigation of an archaeological wood was undertaken to determine the cause of its deterioration. The wood came from a bulwark constructed in early 1100 in the lake Tingstäde Träsk on the island Gotland in Sweden. The samples of the wood, which was identified as Pinus sylvestris, were taken from a depth of 0.85 m below the bottom level. The wood wa...
A P Singh, T Nilsson, G F Daniel
The full guideline for the “double layer test method” - A field test method for determining the durability of wood out of ground
2004 - IRG/WP 04-20290
This guideline describes a test method for wood to be exposed to the weather out of ground contact. The main objective of the method is to evaluate the durability of wood in above ground exposure as shifted overlaid stakes, which form the so called double layer.
The method is applicable to the testing of untreated, treated and modified wood. Initially it was developed and found to be most useful ...
A O Rapp, U Augusta
Treatability of waterstored poles of Norway spruce by sap-displacement and pressure treatment with Boliden K33 and creosote
1973 - IRG/WP 328
Poles of windthrown Norway spruce were stored in bark under water sprinklers for 11-20 months or fully submerged in a lake for 3 years (tab. 1 and 2). Water content after storage is shown in fig. 1 and 8. Treatment with Boliden K33 by sap-displacement (open tank suction) gave a poor result. The Danish requirements of delivery claim a penetration of 20 mm and a net retention of 12 kg/m³ in outer 2...
P Moltesen, E Borsholt, B Bang
Effect of microfibril orientation of bamboo cell wall on soft rot penetration hyphae
1994 - IRG/WP 94-10087
The effect of microfibrillar orientation of bamboo (Phyllostachys virideglaucescence) cell wall on the development of soft rot (Chaetomium globosum) penetration hyphae was investigated. It was found that the soft rot penetration hyphae normally followed the microfibril angle of the cell wall. Bamboo cell walls have alternating broad and narrow lamellae with different microfibrillar angles. The mic...
O Sulaiman, R J Murphy
Raising of the grain and deformation of Scots pine (Pinus sylvestris) treated with water-borne preservatives
1987 - IRG/WP 3456
In Sweden partial impregnation to 10 mm depth of the pine sapwood (class B in the Nordic preservation standard) of joineries was introduced during the seventies. To avoid product quality problems, organic solvent-based systems have been used. However, the Swedish industry today has problems with organic solvents, mainly for environmental reasons. We have studied raising of the grain and deformatio...
G Hägglund, T Sebring
Multiple-Phase Pressure (MPP) Process: Pilot plant trials for disposal of kickback using reverse osmosis membrane filtration
2001 - IRG/WP 01-40202
The MPP Process (a one-stage CCA treatment and accelerated fixation process) generates ~ 250 litres of kickback per cubic metre of timber treated. Composition of kickback is mainly wood sugars and traces of copper, chromium and arsenic. In pilot plant scale trials, MPP process kickback was filtered through a Reverse Osmosis (RO) membrane of a type found from earlier small-scale trials to be the mo...
H Pearson, G Durbin, M E Hedley
Degradation features of waterlogged archaeological compression wood
1998 - IRG/WP 98-10258
The degradation characteristics of waterlogged archaeological compression wood excavated in South Korea were examined by transmission electron microscopy (TEM) and confocal laser scanning microscopy (CLSM). Degradation of Pinus compression wood occurred mainly in the inner part of S2 layer. In contrast, the outer part of S2 layer remained relatively intact. CLSM and TEM showed the erosion type of ...
Yoon Soo Kim, A P Singh
Soft rot
1978 - IRG/WP 179
Soft rot decay of treated wood is examined with special reference to hardwoods treated with CCA. Factors which adversely affect the chances of protection of hardwoods against soft rot are discussed. The ratio of the volume of the fibre cell wall to the volume of the fibre lumen is presented as a major factor influencing final preservative concentration in the fibre cell wall, the major strength co...
C R Levy
L-joint trials: Part 1: Observations on the process of colonisation and decay
2002 - IRG/WP 02-20250
The first trials using the small L-joint, later adopted for use in BS EN 330 and AWPA Standard E9-97 were exposed at BRE in 1975 but all were assessed destructively during the early stages of exposure. The longest running trial which included replicates for long-term exposure will have been exposed for 20 years in July 2002. This paper provides an overview of the results of testing during that p...
J K Carey
A note on the distribution of copper-chrome-boric (CCB) along the culm length of freshly felled bamboo treated by modified Boucherie process
2005 - IRG/WP 05-40317
Preservative treatment of green and dry bamboo poses severe problems. A number of bamboo/ wood preservatives (Chemical formulations) for the destroying organism like fungi, borers and termites etc. In this paper we reported preliminary results of treatment of fresh green round bamboo attached with baranches by modified Boucheri process. Sample full length of an Indian species of bamboo Dendrocalam...
R Lal, C N Vani
Diffuse cavity formation in soft rot of pine
1992 - IRG/WP 92-1541
A new type of soft rot of southern pine longitudinal tracheids is described. In this type, soft rot cavities form by diffuse degradation of the S2 cell wall layer by hyphae growing within the cell wall. Erosion is diffuse and irregular as opposed to the restricted, periodic erosion typical of type 1 soft rot cavity formation. Proboscis hyphae remain small (diameter 0.6 to 0.8 µm) and rapidly auto...
S E Anagnost, J J Worrall, C J K Wang
Development of wood retification process at the industrial stage
1998 - IRG/WP 98-50101-16
Wood is a natural composite material which exhibits outstanding properties from the technical as well as from the ecological point of view. However, it is an anisotropic, hygroscopic material sensitive to biological attacks. We have to stabilise and preserve it if we want to ensure its market shares faced with competing synthetic material, whilst taking the new environmental rules into account.
T...
P Gohar, R Guyonnet
Applications of the shower test. Part A: Results from CCA type C treated wood: influence of fixation process
1993 - IRG/WP 93-50009
This report outlines the results of shower tests conducted on CCA type C treated wood. The results indicate the inherent good fixation of CCA type C, as judged by the leaching limits within the Environmental Regulations. The shower test has proven to be a useful quality control and research test. It determines reasonably accurately the leaching under simulated conditions and, admittedly from a lim...
W J Homan, H Militz, D A Lewis
Studies of the ray parenchyma cell ends on the radial flow of Sitka spruce (Picea sitchensis)
2000 - IRG/WP 00-40164
It is widely accepted that either ray tracheids or ray parenchyma cells offer the major flow pathways radially for the impregnation of softwood with preservative chemicals. It is now generally recognised that, if radial flow does occur through ray parenchyma cells, the cross-field pits play a dominating role for the liquid movement in the radial direction. In this case, the radial flow of fluid is...
I Usta
The use of spruce for transmission poles
1973 - IRG/WP 326
A series of preservative treatments with creosote using Lowry and Rueping schedules was undertaken. From these treatments the most suitable impregnation conditions for water stored Sitka spruce (Picea sitchensis) and Norway spruce (Picea abies) transmission poles were determined. Preservative distribution and permeability values for poles of both species were used to decide the optimum season and ...
J A Dunleavy, D J Balfe, J P Prendergast
Water-storage for improving the permeability of sugi (Cryptomeria japonica D. Don)wood
1999 - IRG/WP 99-40129
The viable bacterial counts in sapwood and intermediate wood of sugi bolts increased immediately after floated in a fresh water pond. Bacterial invasion into the heartwood was not detected apparently during water-storage for 36 weeks, although a few bacterial species have inhabited in freshly-cut heartwood samples. The bacterial species isolated from the water-stored bolts were almost Gramnegative...
S Ohta, S Doi
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