Your search resulted in 260 documents. Displaying 25 entries per page.
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
Resin bleed after light organic solvent preservative treatment - the effect of drying method and process type
1986 - IRG/WP 3378
The effects of drying method and treatment process type on resin bleed were investigated. High-temperature drying of resinous radiata pine (Pinus radiata D. Don) heartwood resulted in improved wood permeability, higher preservative uptake, and greater resin bleed when treated by the Rueping process. Resin bleed was reduced substantially when timber was treated by the Lowry process, and totally eli...
P Vinden
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
N-tritylmorpholine as a potential marine wood protectant against teredinids and pholads - A preliminary evaluation
1983 - IRG/WP 497
The molluscicide, N-tritylmorpholine, is effective in eradicating certain fresh water snails, the intermediate hosts in the transmission of schistosomiasis in man. This preliminary study shows that N-tritylmorpholine is also active against wood-boring marine mollusks. Fine sapwood impregnated with this morpholino compound was not damaged by teredinids or pholads while exposed at two marine sites i...
J D Bultman, K K Parrish
Observations on the uptake and penetration of various liquids in clear heartwood and sapwood of Pinus radiata D.Don
1983 - IRG/WP 3224
Volumetric uptake of water (aqueous copper-chrome-arsenic (CCA)) or methanol, applied by bulk hydrostatic pressure to air dried clear heartwood specimens of Pinus radiata D. Don, far exceeds that of a wide variety of polar and non-polar solvents. In air dried sapwood, the volumetric uptake of CCA tends to be less than that achieved for most solvents including methanol. No comprehensive explanation...
J E Barnacle
A novel defaunation method of the protozoa to investigate cellulose metabolism in Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae)
1994 - IRG/WP 94-10050
The largest protozoa in the hindgut of workers of Formosan subterranean termite, Coptotermes formosanus Shiraki, was selectively eliminated by forced-feeding on low-molecular weight cellulose (LC) with a mean DP of 17. Although one week's feeding on LC caused perfect disappearance of Pseudotrichonympha grassii Koidzumi, the selective defaunation method itself had no detrimental effect on ...
T Yoshimura, K Tsunoda, M Takahashi
The effect of high temperature and long pressing time on the dimensional stability and decay resistance of OSB
2002 - IRG/WP 02-40237
The exterior use of OSB is restricted because when it is exposed to wet conditions swelling, loss of internal bond strength (IB) and decay occur. In this study an alternative process of pressing which results in the production of dimensionally stable and a more decay resistant strandboard was investigated. Boards were pressed at elevated temperatures for prolonged pressing cycles and their physi...
G J Goroyias, M D C Hale
Chromium on the surface of CCA-treated wood
1978 - IRG/WP 386
Chromium in solutions of CCA preservatives is predominantly in the hexavalent state (Cr VI). It is well known that Cr VI is associated with dermatitis and skin ulceration in workers handling chromium containing products and processes. When reduced to the trivalent state, however, chromium is considerably safer. An essential part, therefore, of safety procedures in any chromium - using industry is ...
C R Coggins, P Hiscocks
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
Investigation of microwave as a means of eradicating dry rot attack in buildings
1992 - IRG/WP 92-1545
A microwave-apparatus developed for treatment of building-structures infested by dry rot was tested in the laboratory. The test-conditions simulated treatment of either infested timber or infested brickwork. Sawdust samples, both wet and dry, infested by viable mycelium of Serpula lacrymans were packed in glass-tubes. The tubes were then placed in the middle of either 20 cm thick wooden beams or 3...
C Kjerulf-Jensen, A P Koch
Sludge formation in timber treatment with CCA preservatives. Origin and elimination
1984 - IRG/WP 3276
The exact distributions between lignin and holocellulose and retentions on wood of copper, chromium and arsenic as a function of various sets of conditions in a factorial experiment in which combinations of three temperatures of treatment, three CCA solution concentrations, four pH's of the initial CCA solution and two timber species, namely Pinus radiata and Eucalyptus grandis, are repor...
A Pizzi, W E Conradie, A Jansen
Novel observations on the micromorphology of soft rot attack of wood
1996 - IRG/WP 96-10176
Electron microscopic examinations of decaying Pinus radiata horticultural posts which had been treated with CCA preservative prior to being placed in service about nine years ago showed the presence of soft rot fungi and tunnelling bacteria. Some novel observations on the micromorphology of the soft-rotted areas of tracheid walls are described here. The micromorphology of soft-rotted areas was hig...
A P Singh, R N Wakeling
Acceleration of the fixation of chromated wood preservatives by UV-radiation
1989 - IRG/WP 3544
Preliminary laboratory tests demonstrated that the fixation of chromated water-borne wood preservatives may be accelerated by UV-radiation. The degree of fixation depends on the intensity of radiation and the prevailing temperature. Three hours radiation at 20°C in a device for artificial weathering diminished the leaching of chromium to 43% and of copper to 23% compared to not-radiated samples. ...
H M Illner, H Willeitner, K Brandt
Estimation of the population of a sound colony of Coptotermes lacteus (Froggatt)
1988 - IRG/WP 1353
Selecting an area with a high termite hazard is deemed essential in locating field sites in order to screen potential termiticides and wood preservatives. Yet, quantifying termite populations in such sites remains imprecise. There are major problems associated with estimating populations of termites in mound colonies (either free-standing or in trees), and these are briefly discussed. In this pape...
D M Ewart, J R J French
Preservative effectiveness of medium temperature creosote oil
1990 - IRG/WP 3597
Medium temperature creosote oil (MTC) was prepared by removing light naphthalene oil and heavy anthracene oil from the coal tar by means of fractional distillation. We conducted the effectiveness test of MTC in accordance with the JWPA method for testing effectiveness of surface coatings with preservatives against decay fungi. The soil treatment test against Serpula lacrymans was also carried out ...
S Doi, A Yamada, Y Suda
Practical consequences of the clarification of the chemical mechanism of CCA fixation to wood
1983 - IRG/WP 3220
Practical consequences derived from the chemical investigation of the mechanism of fixation of CCA to the wood constituents are discussed. Among these, formulas for the calculation of the time of hexavalent chrome fixation are presented. Furthermore, three parameters are shown to be important to the long-term effectiveness of CCA-treated timber: (i) the temperature of treatment, (ii) the initial p...
A Pizzi
A Long-term Observation of Termite Activity in The Nest by Continuous Acoustic Emission (AE) Monitoring
2003 - IRG/WP 03-20280
In order to evaluate the influence of temperature on the termite activity, acoustic emission (AE) monitoring was applied to two nests of Coptotermes formosanus SHIRAKI; a nest in the stem of a standing tree and a nest in the underground of a wooden house, respectively. Temperature change in and around the nests were continuously measured for about one year using thermocouples at four points; the c...
Y Yanase, Y Fujii, S Okumura, T Yoshimura, Y Imamura
Low-toxicity DNBP wood preservatives
1987 - IRG/WP 3408
Low and very low toxicity single compound preservatives of both excellent insecticidal and fungicidal activity for interior, extrior and ground-contact applications are presented. These are ester derivatives of alkyl dinitrophenols, in particular of 2-sec-butyl-4,6-dinitrophenol (DNBP) and 2-sec-octyl-4,6-dinitrophenol. These esters, of much lower toxicity than DNBP impart to the treated timber co...
A Pizzi, W E Conradie, A Jansen, R Vosloo
A laboratory evaluation of the fumigant, sulfuryl fluoride (VikaneR), against the Formosan termite Coptotermes formosanus Shiraki
1982 - IRG/WP 1164
A series of laboratory experiments showed that the fumigant sulfuryl fluoride (VikaneR) was effective against small groups of Coptotermes formosanus Shiraki exposed to the gas directly at temperatures from 20-40°C. At 10°C fumigations failed regardless of initial gas concentration. Very high or total mortality was observed at concentrations of 0.79 cc/L or higher. A second series of experiments ...
J P La Fage, M Jones, T Lawrence
Experiences from a Danish large scale test by means of a new method of treatment by attack of true dry rot fungus (Serpula lacrymans) in buildings
1994 - IRG/WP 94-10064
Experiences from a new and epoch-making method of treatment in connection with the repair of attack of the true dry rot fungus, Serpula lacrymans (Fr.) S.F. Gray, are described. The paper presents the background of a large scale test comprising repair of more than 150 Danish buildings over a period of approximate 5 years. The method being both gentle to the building and presenting savings of at le...
O Munck, H Sundberg
Investigation of temperature effect on fixation of Celcure preservative (ACC) in beech (Fagus orientalis)
2001 - IRG/WP 01-40200
In this research, the fixation speed of Celcure 2% (ACC) preservative salt, under temperature of 17°C, 27°C and 50°C, on intact and stained wood specimens of beech was investigated. For this purpose, blocks of wood with 5x5x7 cm dimensions were prepared and saturated with 2% ACC concentration by full-cell process. The specimens were put in three incubators at the above-mentioned temperatures. F...
A Karimi, M Ghorbani
The degradation of wood surfaces by water
1984 - IRG/WP 3289
Thin radial/longitudinal sections (~100 µ) of Scots Pine (Pinus sylvestris) and lime (Tilia vulgaris), were exposed to deionised water over the temperature range 25-65°C. Losses in wet tensile strength and toughness occurred rapidly at temperatures from about 50°C upwards. After about 2 months' exposure pine lost some 10-30% of its tensile strength and 20-60% of its toughness. For lime...
W B Banks, P D Evans
Laboratory induction of pupation and emergence in Anobium punctatum (Deg) (Col Anobiidae)
1973 - IRG/WP 219
The reluctance of Anobium punctatum to pupate and emerge outside its normal summer emergence period has led to attempts to induce pupation by artificial manipulation of the temperature conditions at which larvae are held. Infested hazel (Corylus avellana) twigs were subjected to temperature schedules which simulated some aspects of a spring climate. It was found that 40 days of a diurnal temperatu...
R W Berry
Influence of concentration, catalyst, and temperature on dimensional stability of DMDHEU modified scots pine
1998 - IRG/WP 98-40119
Dimethyloldihydroxyethyleneurea (DMDHEU) is being used in textile industry to improve wrinkle recovery. Trials on solid wood have been performed to minimise swelling of the wood. This paper focuses on the effect of various types and concentrations of catalyst and reaction temperature on the dimensional stability of Scots pine. Three different catalysts, NKS (based on magnesium chloride), 3282 (bas...
M Van der Zee, E P J Beckers, H Militz
Low polymer levels containing bioactive monomer polymerized in situ provide resistance to Gloeophyllum trabeum
1995 - IRG/WP 95-30066
Wood preservation based on in situ polymerization of potentially bioactive monomers has been studied. Tributyltin oxide acrylate (TBTOA) and pentachlorophenol acrylate (PCPA) were synthesized. Wood samples were treated at 2, 5, 10, 15 and 20% by weight solutions with varying amounts of crosslinker (trimethylolpropane trimethacrylate, TMPTM) and polymerized in situ in wood samples (2.54 x 2.54 x 0....
R E Ibach, R M Rowell