Your search resulted in 591 documents. Displaying 25 entries per page.
Essais mycologiques sur poteaux traités à la Wolmanit C B
1974 - IRG/WP 339
D Ollier, C Jacquiot
Contribution to the testing of wood based board material
1982 - IRG/WP 2176
R G Lea
Study of the natural durability and impregnability of a metropolitan species of tree
1986 - IRG/WP 2261
The current and predictable evolution of construction timber supply conditions is motivating research for a more efficient utilization of native woods. It is now important to determine statistically reliable impregnability values on a national scale, and to evaluate the natural durability of woods recently introduced in France, or economically important native woods.
M E Mathieu
Sub-group on Basidiomycete tests: Proposals for Sub-group programme of work
1979 - IRG/WP 2127
During the IRG 10 Meetings in Peebles, Scotland in September 1978, it was resolved to establish within Working Group II a sub-group on testing wood preservatives against basidiomycete fungi. The terms of reference and scope of the sub-group's activities were to be determined by consensus among members who registered an interest. Dr A F Bravery (PRL, UK) was asked to act as co-ordinator. During the course of the Peebles Meeting the following members registered their intention to participate: Dr D Aston (UK), Dr C Coggins (UK), Mr G Fahlstrom (USA), Professor D French (USA), Professor C Jacquiot (France), Mr B Jensen (Denmark), Dr A Ofusu-Asiedu (Ghana), Miss J Taylor (UK). Since there was insufficient time to convene an inaugural meeting in Peebles the present paper has been prepared as a basis for discussions and to facilitate initiation of active collaboration. It is hoped that members will offer individual comment in order to define the desirable scope of the sub-group's work and to refine ideas for collaborative or co-ordinated experimental work.
A F Bravery
A laboratory evaluation of the susceptibility to biological attack of glued laminated pine timber
1991 - IRG/WP 2387
In the scope of a research programme concerning the use of maritime pine (Pinus pinaster) to produce glued laminated timber structures in Portugal, the natural durability of this material was checked by using laboratory test methods. An European standard, EN 113, was used to test durability against basidiomycetes and a test method developed at LNEC for termites was adapted for this purpose. From the results obtained, it seems that the existence of glue layers does not influence the natural durability of the material under basidiomycetes attack. As for termites the method used indicates that they are unable to cross the glue layers though this effect would hardly be of importance for practical uses.
L Nunes, H Cruz
Determination of toxic limits of wood preservatives towards wood-destroying Basidiomycetes. Investigation on the effect of the use of two impregnated wood blocks and of one impregnated and an untreated block respectively in Kolle jars on the toxic limits of wood preservatives
1973 - IRG/WP 225
Some experiments with hexabutylditin against fungi
1977 - IRG/WP 388
The investigation was carried out in 1972 and 1973 to collect experimental data about the poisonousness of hexabutylditin (HBDT) against the woodrotting fungi Coniophora puteana (Coniophora cerebella), strain 15, and Chaetomium globosum, strain hexabutylditin was being manufactured by the Organisch Chemisch Instituut (O.C.I.) TNO, at Utrecht.
J W P T Van der Drift
The variability of preservative distribution in test blocks
1973 - IRG/WP 220
The techniques for the assessment of likely effectiveness of preservative systems have long been the subject of much discussion. The whole field has recently been reviewed by Hilditch and Hamblyn (1971) who described in detail many of the laboratory test procedures used, but who also indicated the deficiencies in many of these techniques. It has long been the view of many associated with the wood preservation industry that laboratory tests can only serve as a preliminary method of screening and that final approval by both the company marketing the development and independent authorities, on whom the burden of approval rests, can only be given after detailed testing in the field. The aim of the simple piece of work described in this paper, is to lok at the variability which one might expect in the distribution of preservative in test blocks destined for laboratory fungal evaluation.
F W Brooks, M R Gayles, R W Watson
The use of plastic meshes in soft rot monoculture testing
1990 - IRG/WP 2353
Plastic meshes were introduced between the wood blocks and agar medium in a miniaturised soft rot monoculture test in order to minimise transfer of the preservative from the wood and mineral salts from the agar. Although several different sizes and types of mesh were used and the blocks were wetted up to an appropriate moisture content for soft rot attack the amount of decay was substantially reduced compared with the controls. Addition of mineral salts to the wood blocks in similar quantities to those in the agar aided decay but did not provide suitable conditions for maximum loss in weight.
S M Gray
Comparison between agar-block and soil-block methods for wood-destroying Basidiomycetes
1992 - IRG/WP 92-2401
The object of this work is to compare these methods in order to provide some information to help in the choice between them. The comparison was made by a statistical analysis (factorial completely randomized design) and by a discussion about other aspects of each method. An evaluation of some fungi on attacking wood and a comparison between Picnoporus sanguineus isolated from carpophore and decayed wood were made. The results indicated that the loss of mass was greater in soil-block. Besides, the activity of the fungi in this method was more homogeneous than in agar-block. However the soil-block method presents some difficulties not found in the agar-block method. As related to the performance of Picnoporus sanguineus strains, the greater loss of mass occured when it was isolated from carpophore, no matter what method was used. These results give important indications about the biological characteristics and the source of the strains.
M B B Monteiro, S Brazolin, G Catanozi
Assessment of the toxicity of some copper-, zinc- and boron-based wood preservatives to the cellar fungus Coniophora cerebella Schröet
1974 - IRG/WP 242
This article reports the use of a method based on the determination of the probability of the protection of timber against destruction by fungi. By converting the probability values to probit values and plotting them as a function of the amount of preservative retained in the timber, curves of the toxic effect are obtained, enabling any timber protection probability to be assessed.
V N Sozonova, D A Belenkov
Fungi used in standard tests on the toxicity value of wood preservatives in various European countries
1975 - IRG/WP 255
The aim of the present paper is to make the comparative analysis of test fungi used in various European countries in order to define the toxicity value of wood preservatives against fungi of the Basidiomycetes class. Only the methods with national standard rank, present on the currently binding standards list are taken for consideration. The analysis of similarities and differences in the choice of test fungi used in these methods should be a further step in the investigation on the unification of the test methods
Preliminary results of the treatment of wood with chlorosilanes
1981 - IRG/WP 3172
It is clear from the initial data reported here that the treatment of pine sapwood with chlorosilanes under the reaction conditions employed did not significantly reduce the decay by both white rot and brown rot fungi. Only the dichlorosilane compounds showed to possess some protective action against fungal attack. Before drawing conclusions on the application of organosilicon compounds as potentially alternative wood preservatives much more work is needed. At present the anti-blue stain activity of the different types of chlorosilanes is being tested. Further investigation on the treatment is also required with respect to the effect of wood moisture content and the use of other types of acid acceptor on the silylation reaction. Current studies also deal with the effect of the treatment on physical and mechanical properties of wood. The initial physical tests on the sorptive and dimensional behaviour of treated wood revealed that the dichlorosilanes might give better results again.
Hygroscopicity of decayed wood - Implications for weight loss determinations
1996 - IRG/WP 96-20085
Hygroscopicity changes were observed in red maple blocks subjected to brown rot, white rot and soft rot. Brown rot reduced hygroscopicity, soft rot increased hygroscopicity, and white rot showed only a very slight increase in hygroscopicity. The effect of these changes on weight loss tests is a slight overestimation of weight loss for brown rot and a slight underestimation for soft rot and white rot. Hygroscopicity changes were similar prior to and after oven drying for white rot and soft rot, while for brown rot, the reduction in hygroscopicity was enhanced by oven-drying.
S E Anagnost, W B Smith
Resistance of various wood species against decay by Coniophora cerebella (Pers) Duby and Lenzites trabea (Pers) Bres
1976 - IRG/WP 142
Both fungi, Coniophora cerebella and Lenzites trabea, are important destroyers of timber. Coniophora often occurs inside buildings and Lenzites trabea has been observed on southern facades of buildings, on balconies and window frames. In most instances that we investigated coniferous timber had been decayed. But both species are known to attack also various hardwoods. For this reason tests similar to those carried out with Serpula lacrymans (see O. Wächli, Holz als Roh- und Werkstoff, 31, (1973) 96-102), have been made with both fungi on various home-grown and foreign wood species.
Evaluation of bacteria for biological control of wood decay
1990 - IRG/WP 1426
Laboratory soil-block and agar-block tests were carried out to evaluate the efficacy of bacteria as biological control agents against 5 brown-rot and 3 white-rot fungi. Pretreatment of Southern pine and sweetgum with a bacterial solution prevented decay in agar-block tests. However, the bacteria were generally ineffective in preventing decay in Southern pine, Douglas-fir, sweetgum and yellow poplar in soil-block tests. Wood blocks treated with an autoclaved bacterial solution were not decay resistant by either test method.
R Benko, T L Highley
Fungitoxic effect of the quaternary ammonium compounds preservatives against Basidiomycetes by using agar-plate and agar-block methods
1996 - IRG/WP 96-30118
Results of investigations on the fungitoxic value of three versions of wood preservatives based on the quaternary ammonium compounds (lauryldimethylbenzylammonium chloride, lauryldimethyl-benzylammonium bromide and alkylbenzyldimethylammonium chloride) and borates in relation to the wood destroying fungi have been presented. The agar-plate (screening) and agar-block method were applied. A wide range of the fungitoxic activity of all the three formulations and a very small leachability were proved.
J Wazny, P Rudniewski
On the laboratory use of X-rays in timber decay evaluations
1981 - IRG/WP 2144
The paper reports the results of laboratory experiments on the X-raying of some Pinus radiata sapwood blocks infected with Serpula lacrymans to determine the effect of density and moisture content on the absorption of X-rays by wood. It is concluded that with increasing moisture content there is a very marked increase in time required to pass a constant quantity of X-rays through a test block and the interpretation of X-ray data taken at unknown moisture contents may be questionable.
J D Thornton, J W Creffield, O Collett
Bestimmung der pilzwidrigen Wirksamkeit von Holzschutzmitteln gegen Moderfäule-Erreger
1977 - IRG/WP 2125
Ziel der vorliegenden Arbeit war der Vergleich der in verschiedenen Ländern zur Bestimmung der pilzwidrigen Wirksamkeit von Holzschutzmitteln gegen Moderfäule-Erreger angewandten Methoden. Als Vergleichsmaterial dienten drei normierte Methoden: die britische (42), skandinavische (45) und die in der DDR angewendete (47) sowie wichtige, von verschiedenen Fachleuten ausgeführte Arbeiten experimentellen Charakters. Die Analyse betraf vor allem folgende Probleme: Bereich der Anwendung der Methoden, Trägersubstanz, Testorganismen, Bewertungskriterien der Ergebnisse sowie andere Fragenkomplexe. Es wurden die aktuellen Untersuchungsmethoden zur Bestimmung der pilzwidrigen Wirksamkeit von Holzschutzmitteln gegen Moderfäule-Erreger, die in verschiedenen Forschungsarbeiten angewendet worden waren, durchgesehen. Festgestellt wurden sehr starke Unterschiede der methodischen Grundsätze, die sowohl zwischen den Methoden als auch im Rahmen der verschiedenen Typen von Methoden bestehen; diese Unterschiede betreffen vor allem die für die Pilzzucht angewandten Nährböden, die Ausmaße der Proben, die Auswahl der zu untersuchenden Organismen u. a. m. Von den drei Arten der Methoden: dem Agar-Klötzchen-, Erde-Klötzchen- und Vermiculit-Klötzchen-Verfahren scheint besonders das letzte hinsichtlich der Wiederholbarkeit als auch im Hinblick auf die Vergleichsmöglichkeiten der erhaltenen Ergebnisse geeignet zu sein.
Laboratory tests on the natural durability of timber methods and problems
1984 - IRG/WP 2217
In literature a large variety of test methods is mentioned to examine the natural resistance of timber against fungal attack. This concerns the kind of sampling as well as the test procedure, the test fungi, the duration of test, and the classification of the resistance according to the test results. These variations, however, are of great influence on the test result. Long term exposure will lead to a further differentiation of timber species to be generally known as "resistant".
Toxic values derived from EN 113 tests - are they determined by the virulence of a test fungus?
- Results from a round robin test -
1999 - IRG/WP 99-20176
The virulence of Coniophora puteana BAM Ebw. 15, the obligatory test fungus on softwood in tests according to EN 113, is known to be rather inconstant at least in some laboratories. The mass losses of untreated Scots pine sapwood blocks in an EN 113 test may range from below 20% to up to more than 50%. Possible reasons for these differences as well as the impact of a low virulence on the toxic values of a preservative under test were discussed and a round robin test with subcultures of C. puteana Ebw.15 and of Poria placenta FPRL 280 of different virulence and origin was carried out. Subcultures of both test fungi considered as either virulent or weak were distributed by there laboratories of origin. All test specimens originated from one laboratory. They were treated with a CCB salt by another laboratory and distributed to the partners. The results show that the virulence of identical subcultures may differ remarkable most probably depending on the culture conditions of the laboratories involved.In the case of P. placenta differences in virulences did not cause different toxic values in the round robin test. In the case of C.puteana, however, different toxic values were obtained. Furthermore, this fungus showed an increased sensitive behaviour to varying test conditions. A virulence <40% of C. puteana generally reduced the toxic value at least by one concentration.
H Leithoff, R-D Peek, H V Borck, R Goettsche, H Kirk, M Grinda
Screening wood preservatives: Comparison of the soil block, agar block and agar plate tests
1993 - IRG/WP 93-20001
Several test procedures have been developed over the years to screen potential biocides for their value as wood preservatives. Each test has inherent advantages and disadvantages. In this paper the relative merits of the soil block, agar block and agar plate tests are compared. Eight commercially available biocides encompassing inorganic and organic systems were tested against four basidiomycete decay fungi. Each biocide was ranked according to its performance in the three tests. The results show that the relative efficacy of the different biocides is dependent on the screening test. Biocides can be separated on the basis of their chemistry. "Fixed" inorganic preservative systems perform better in tests which employ wood as a substrate material. Organic systems perform well in both the agar plate and wood-containing tests. Furthermore, the agar plate technique shows promise for detecting synergism between biocide components. It is concluded that all of these test methods should be considered to efficiently screen biocides for use as wood preservatives.
K J Archer, D D Nicholas, T Schultz
A laboratory evaluation of tributyltin ethanesulphonate as an aqueous fungicide in wood preservation
1983 - IRG/WP 3229
Toxic limit data, using both leached and unleached wood test blocks, are reported for aqueous solutions of tributyltin ethanesulphonate against four Basidiomycete fungi, Poria placenta, Gloeophyllum trabeum, Coriolus versicolor and Coniophora puteana. An in situ study of the tributyltin compound in Scots pine and ponderosa pine sapwood has been carried out, using the technique of 119mSn Mössbauer spectroscopy.
R Hill, P J Smith, J N R Ruddick, K W Sweatman
Evaluating the performance of wood preservatives against fungi
1974 - IRG/WP 247
A compilation is made of results published by various workers for agar/block laboratory tests of the effectiveness of wood preservatives against 11 species of wood destroying Basidiomycetes and one species of soft rot fungus. Preservatives include creosote, boron, metal/arsenic mixtures, metallic naphthenates, chlorinated naphthalene, chlorinated phenols and tri-n-butyl tin oxide. The results are compared statistically and the causes of the variance between different estimates examined. The limitations of agar/block and other laboratory tests as predictors of performance in the evaluation of preservatives are discussed.
Determination of fungitoxic value of preservatives in laboratory wood-block tests. Part 2: Statistical estimation
1989 - IRG/WP 2327
Laboratory modified agar-block tests were made to determine the fungitoxic value of the wood preservative CCA against the test fungus Serpula lacrymans using statistical methods. With the aid of statistical computer programmes based on the least square method. the regression equation was found for the dependence between sample mass loss and preservative retention both in terms of percentage and following probit, decimal and natural logarithmic transformations. The fungitoxic value was found to be lying in the point of intersection between the lines calculated and that of a 3 per cent mass loss. The application of mathematical statistics seems to have increased the objectivity and repeatability of measurements of fungitoxic value in the case of this wood preservative.
J Wazny, J D Thornton, K J Krajewski