Your search resulted in 1546 documents. Displaying 25 entries per page.
The effect of moisture content on the electrical resistance of timber as detected by a pulsed current reistance meter (Shigometer)
1984 - IRG/WP 2212
The literature concerning the use of the Shigometer® for detecting decay in standing trees and wood poles is reviewed and the differences of opinion over the effect of timber moisture content on electrical resistance are highlighted. A simple experiment designed to test this effect is described and the implications of the results for testing poles in service are discussed. There was a large diffe...
P I Morris, D J Dickinson
Shorter-term biological control of wood decay in pre-seasoning pine roundwood as an alternative to chemical methods
1992 - IRG/WP 92-1555
Previous studies on the long-term control of decay in creosoted transmission poles, using Trichoderma and other antagonistic moulds, have met with limited success. However, it is possible biological control is more suited to control of decay on shorter time scales. An earlier study, focusing on pre-seasoning treatment of transmission poles showed that favourable porosity increases could be brought...
M W Schoeman, D J Dickinson
Isolation of a gene from the melanin pathway of the sapstaining fungi Ophiostoma piceae using PCR
1997 - IRG/WP 97-10219
To prevent sapstaining fungi from discoloring wood, it is necessary to determine what factors affect the biosynthesis and characteristics of the pigment(s) and to identify the genes involved in the pathway. Using inhibitors and heterologous DNA probes from Alternaria alternata, we suggest that melanin, the pigment of Ophiostoma piceae, is produced by the dihydroxynaphthalene (DHN) pathway. Recentl...
R Eagen, J Kronstad, C Breuil
Factors affecting decay rates in a fungus cellar
1985 - IRG/WP 2242
Birch and pine stakes treated with chromated copper arsenate and didecyldimethylammonium chloride were incubated in two soils in a "Fungus Cellar" test. At three month intervals, sets of stakes were inspected and assigned visual ratings or removed from the soil beds for weight loss determination. Preliminary results after nine months exposure have shown differences in the decay rates between birch...
P A McKaig
The use of fumigants for controlling decay of wood: a review of their efficacy and safety
1989 - IRG/WP 3525
Volatile agricultural chemicals (fumigants) such as chloropicrin (trichloronitromethane) and sodium n-methyldithiocarbamate have been used in the United States for controlling internal decay of large dimension wood products for over 20 years. This usage has been concentrated in the electric utility industry, but fumigants are increasingly applied to protect bridge timbers, marine piling, and even ...
J J Morrell
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
Effects of pre-harvest girdling on selected properties of red pine, red maple and Eastern larch
1999 - IRG/WP 99-40137
Trees of three species - tamarack (Larix laricina), soft maple (Acer rubrum) and red pine (Pinus resinosa) - were girdled immediately below the crown,one to two years before felling. The wood from these trees was compared with wood taken from un-girdled control trees felled at the same. Sapwood and heartwood, from the controls, and from above and below the girdle of treated trees, were examined fo...
A Taylor, P A Cooper
Moisture content and other tested values in. Double layer tests of different size in Lithuania and Germany
2004 - IRG/WP 04-20299
The paper presents measurement results of moisture content and the analysis of durability trial of double layer wood in variants of varying size, conducted in Girionys, Kaunas distr., Lithuania and in Hamburg, Germany. In this trial 3 sample sets of varying size, containing 25, 50 and 100 specimens, are used. The aim of this trial is to ascertain an optimal number of test specimens. The dynamics o...
J Saladis, A O Rapp
Natural decay resistance of some lesser known /used timber species from the forests of Tanzania
2005 - IRG/WP 05-10557
In order to manage the Tropical forest in a sustainable manner and increase the resource base for their wood industries, many Tropical African timber producing countries including Tanzania are promoting the many lesser known/used timbers in their forests as alternative sources of wood to the over-exploited primary timber species. Four lesser known/utilized timber species from the forests of Tanzan...
S A Amartey, P R Gillah, R C Ishengoma, J Gabriel, D H Kitojo
Extracellular carbohydrate production by isolates of Postia (=Poria) placenta
1989 - IRG/WP 1388
A monokaryotic strain of Postia (=Poria) placenta, ME20, which is unable to degrade wood, also failed to produce extracellular polysaccharide when grown in liquid culture, regardless of carbon source or concentration. Other isolates of Postia placenta, including another monokaryon and a hybrid of this monokaryon with ME20, produced large quantities of this material. The polysaccharide consisted pr...
J A Micales, A L Richter, T L Highley
Selecting fumigants for treatment of internal decay in wood
1986 - IRG/WP 3370
A number of potential fumigants were screened with respect to their toxicity to decay fungi, (Poria carbonica, and Lentinus lepideus) and their sorption characteristics on Douglas Fir (Pseudotsuga menziesii Mirb. Franco) wood. Wafers of infected wood were exposed to different fumigant concentrations for various times then cultured to determine viability. The lethal concentration X time (ct) factor...
P A Cooper
Moisture Adsorption Behaviour of Rubber Wood Decayed by Brown and White rot Fungi
2005 - IRG/WP 05-40306
Moisture adsorption behaviour of rubber wood blocks decayed by each brown rot and white rot fungi was studied. The adsorption isotherms of decayed wood were compared with the isotherm of undecayed wood. The wood decayed by brown rot adsorbed less moisture as compared to sound or undecayed wood at all humidity levels. No significant difference was observed in adsorption behaviour of white rot dec...
S S Chauhan, H C Nagaveni
Collaborative soft rot tests: Specific gravity loss resulting from soft rot
1973 - IRG/WP 227
It was proposed at the 5th meeting of Working Group II of the IRG in June 1973 in Lahti, Finland, that the specific gravity (swollen volume basis) of test blocks used in the IRG Collaborative Soft Rot Tests should be determined on all the blocks at the completion of the exposure period. Specific gravity determined on the basis of the oven dry weight and water swollen volume was selected because (1...
C R Levy
Movement of chloropicrin, Vapam, and methylisothiocyanate in southern pine and Douglas fir timbers
1987 - IRG/WP 3410
Douglas fir and southern pine timbers, 15.2 x 15.2 x 426 cm³ (6-in x 6-in x 14-ft), were "inoculated" with brown-rot and white-rot fungi as vapor-sensing agents to evaluate the movement and distribution of fungitoxic concentrations of chloropicrin, Vapam, and methylisothiocyanate (MIT) over a 20-week period. Residual fumigant in timbers was determined by a bioassay with Gloeophyllum trabeum. The ...
T L Highley
Mycoparasitism by some white rot fungi on blue stain fungi in culture
1986 - IRG/WP 1304
When studying biological control of blue stain an interesting phenomenon of parasitism by some white rot fungi on blue stain fungi has been encountered. The majority of the 22 tested white rot fungi act parasitically upon blue stain fungi. The most interesting species among them is Bjerkandera adusta (Willd. ex Fr.) Karst., causing almost complete or complete decoloration of the hyphae of the blue...
R Benko, B Henningsson
Water transfer in wood in relation to fungal attack in building - Effect of condensation and diffusion
1992 - IRG/WP 92-1543
Wood is continuously exchanging moisture with the surrounding atmosphere, the temperature and relative humidity are important factors. Wood moisture in this case is not enough to provoque decay by fungi. However, when, during the night, condensation appears cyclically, wood absorbs water and moisture content may be sufficiently high to allow development if drying does not take place. The water tra...
D Dirol, J-M Vergnaud
Bethoguard; A new wood protecting fungicide for use in metal free ground contact wood preservatives
2002 - IRG/WP 02-30301
Research has identified the limitations in both the spectrum of activity and permanence of organic biocides placed in wood in high hazard environments, particularly in the absence of heavy metals such as copper. More specifically, the control of soft rot decay in wood in soil contact has proven to be most problematic.
The new organic biocide, Bethoguard; an oxathiazine, has demonstrated excellen...
S C Forster, G R Williams, M Van Der Flaas, M Bacon, J Gors
Pretreatment decay in poles of Pinus sylvestris
1987 - IRG/WP 1329
Storage damage by blue stain and decay in poles before impregnation has been increasingly observed during recent years and there have been reports that salt-impregnated poles today are of lower quality because of incipient decay being increasingly common. The attacks may have started at the time of cutting and then continued during the period of seasoning at the plant, which could be as long as tw...
H Lundström, M-L Edlund
Why don't more people work with Serpula lacrymans nowadays? A discussion of some of the different approaches to experimenting with this unique fungus
1989 - IRG/WP 1383
Remarkably few laboratories are currently investigating this well-known fungus. Not only has it failed to gain acceptance as a standard test organism (for wood preservative evaluation) in many countries, but is also sometimes excluded from pure research studies when it ought to be an obvious first choice as a representative basidiomycete. This paper discusses some different approaches that have be...
J D Thornton
Soft rot - Soil burial - Tests. Influence of the addition of nitrogen compounds to the soil on wood decay by soft rot
1972 - IRG/WP 213
The decay of wood specimens buried in soil is influenced by various factors. Decisive are the water content, the content of organic substances, the pH-value, the content of mineral nutritive salts, nitrogen content, etc. of the soil. These tests were carried out in order to investigate if the decay of wood in the soil will be influenced by additions of various nitrogen-compounds in different conce...
O Wälchli
Leaching tests on CCA-treated wood using inorganic salt solutions
1984 - IRG/WP 3310
Pinus radiata sapwood treated to approximately 10 kg/m³ with Tanalith NCA or Tanalith C-type CCA preservatives was ground to a fine powder and samples were then leached with solutions of calcium chloride, calcium nitrate, magnesium nitrate, or a mixture of potassium di-hydrogen orthophosphate and di-potassium hydrogen orthophosphate, at 0.03M-1.00M solution concentrations. Leached wood samples we...
D V Plackett
Characterization and differentiation of wood rotting fungi by protein and enzyme patterns
1999 - IRG/WP 99-20177
Standardized tests for wood preservatives are performed with defined fungal strains to ensure comparability between laboratories. However, changes of virulence and variation of results are well known events. Suitable and reliable measures to control the stability of the test organisms are necessary.Comparison of protein patterns produced by SDS-electrophoresis was already described by several auth...
U Schoknecht
Methods of testing anti-stain chemicals for protecting sawn timber during storage and transport
1976 - IRG/WP 273
No international standard method for testing anti-stain chemicals for protecting fresh sawn timber exists. The methods used can be divided into three types: a) Rapid screening tests for finding chemicals effective against blue-stain and mould fungi. The chemicals are tested in agar medium, in pieces of filter paper or on small pieces of wood using pure cultures. b) Laboratory tests for evaluating ...
T Vihavainen
A non-destructive testing technique for wood poles
1987 - IRG/WP 2293
A method has been developed to evaluate the stiffness and condition of a wood pole based on structural dynamics. This paper describes the results of tests performed on nearly 200 wood utility poles across Western Canada. A high correlation exists between the dynamic non-destructive test and direct mechanical tests. The need for an accurate non-destructive testing technique is demonstrated by the f...
W M Murphy, D E Franklin, R A Palylyk
Wood cement composites using spent CCA treated wood
1999 - IRG/WP 99-50126
The feasibility of using spent or out-of-service CCA treated wood as a component of wood/cement composites was evaluated. Cold pressed wood particle cement boards were made using CCA treated particles from a red pine (Pinus resinosa Ait.) pole removed from service and from untreated red pine wood from a new pole. Boards were manufactured using a range of wood to cement ratios and water to cement r...
Chen Huang, P A Cooper