Your search resulted in 239 documents. Displaying 25 entries per page.
Microdistribution of Copper in Copper-Ethanolamine (Cu-EA) Treated Southern Yellow Pine (Pinus spp.) related to density distribution
2004 - IRG/WP 04-40270
The relationship between copper absorption and density distribution in wood cell walls was investigated in this study. The density distribution on layer level was obtained from two approaches: (1) calculation by using data obtained from literature; (2) microdistribution of carbon and oxygen atoms in the wood cell. The microdistribution of carbon and oxygen in untreated southern yellow pine (Pinus spp.) sapwood, as well as copper in cell walls of copper-ethanolamine (Cu-EA) treated wood was determined by scanning electron microscopy coupled with energy dispersive X-Ray analysis (SEM-EDXA). Both approaches for density distribution led to the same result: the density was higher in the compound middle lamella (ML) and cell corners (CC) than in the secondary wall. The concentration / intensity of Cu, C and O in the cell wall follow the same trend as the density distribution; suggesting that density may play a major role in SEM-EDXA study of the distribution of metal-containing wood preservatives within the wood cell wall.
Jinzhen Cao, D P Kamdem, E Pasek
Statistical analysis of durability tests - Part 1: Principles of distribution fitting and application on laboratory tests
2013 - IRG/WP 13-20504
Service life prediction is an important topic in wood research, especially with regard to the Construction Products Regulation (CPR). Both laboratory tests as well as in-service performance testing are therefore essential in combination with proper monitoring and analysis tools. A crucial concept is variability in testing and analysis, especially for a biological material such as wood. The larger the sample size the more representative this is for the entire population, yet the number of specimens is often limited by a financial upper limit. Therefore it is essential to use the sub-optimal amount of data and assess as accurately as possible the characteristic under study. In this paper we focus on the use of probability density functions (pdf), also known as distributions. The principles and guidelines for pdf fitting will be explored as well as the use of confidence intervals. The theoretical concepts will be applied on mass loss data. Intra- and interspecies variability but also inter-laboratory variability is illustrated. Therefore the analysis of test results of a round-robin as described in Brischke and co-workers (2013) will be illustrated as well as the analysis of lab tests performed at Woodlab-UGent according to CEN/TS 15083-1 (2005). A validation procedure, as part of a future updated standard, can be useful to erase inter-laboratory differences. Furthermore, the use of a reference wood species can also be an option as a benchmark to compare other species rather than using ‘absolute’ testing resulting in a ranking based on median values. In Part 2 of this paper we will then further use the concepts of pdf fitting for time-to-failure analysis of field test data.
I De Windt, J Van den Bulcke, C Brischke, C R Welzbacher, A Gellerich, S Bollmus, M Humar,
Solvent drying and preservation of timber
1977 - IRG/WP 381
Processes which combine drying and preservation are first reviewed. Some preliminary experiments are then described in which blocks of green Sitka spruce sapwood were immersed, in a solution of tributyltin oxide (TBTO) in methanol at 60°C. Satisfactory penetration of the preservative and exchange of methanol and water occurred in a few hours. The methanol was removed rapidly from the wood by evaporation. Satisfactory penetration of TBTO into initially methanol-saturated samples occurred in a similar period. The factors influencing. such treatments are discussed. High initial moisture content of the wood and a high operating temperature are particularly desirable. Some aspects of the possible commercial operation of the process are discussed.
J A Petty
Working Group I Sub-group 5 'Insects in dry wood'. Plan for data sheets
1982 - IRG/WP 1173
Penichroa fasciata (Stephens) (Col. Cerambycidae) a pest in wood materials
1988 - IRG/WP 1365
Penichroa fasciata (Stephens) (Col. Cerambycidae) is found to be a frequent pest occurring in hardwood in storage in Italy. This paper reports the characteristic for identification, biological features, distribution and timber liable to attack.
A Gambetta, E Orlandi.
The restricted distribution of Serpula lacrymans in Australian buildings
1989 - IRG/WP 1382
Temperature data has been gathered over a number of years, not only for flooring regions of various buildings in Melbourne, but also within roof spaces and external to the buildings. Findings are discussed in relation to the distribution of Serpula lacrymans within Australia, its restriction to certain types of building construction and its restriction to flooring regions. The subfloor spaces of badly-ventilated, masonry buildings are highlighted as being better suited than are the subfloor spaces of, for example, Japanese buildings for the activity of this fungus. Hence Serpula lacrymans is very restricted in its distribution in Australia, yet where it is active it does grow rapidly and causes rapid flooring failures.
J D Thornton
Results of chemical analyses in the field of wood preservation in the Bundesanstalt für Materialprüfung
1973 - IRG/WP 321
The results of qualitative and quantitative chemical analyses of wood preservatives are often the basis for evaluating the various works in the field of wood preservation. In the past 10 to 15 years a number of such works was carried out in the Bundesanstalt fur Materialprüfung, Berlin-Dahlem, dealing with the identification and effectiveness of wood preservatives and with methods of wood preservation. Fundamental realisations were made which will be summarised below. It seems advisable to differentiate between inorganic and organic chemical wood preservatives and methods of analyses. These are two distinct fields which differ also with regard to the analytical techniques applied.
H J Petrowitz
Extending the useful life of creosoted electricity distribution poles in service
1993 - IRG/WP 93-50001-16
Creosoted transmission poles have provided good service over many decades in a whole range of environments. The use of save biocides for secondary treatments has the potential to extend the life of such poles. These techniques, together with a full understanding of the modes of failure, make it possible to establish new strategies to further improve the environmental benefits of treated wooden poles.
D J Dickinson, B Calver
Light organic solvent preservative treatment schedules for New Zealand-grown radiata pine
1986 - IRG/WP 3379
The influence of pressure differential and treatment time on preservative uptake and distribution in radiata pine heartwood and sapwood is investigated. Treatment schedules are defined which minimise solvent usage but ensure complete sapwood penetration and optimise heartwood penetration.
Annotated check-list of the Limnoriidae
1990 - IRG/WP 4160
The crustacean isopod family Limnoriidae comprises 51 species of marine borers. A list of species is provided, together with notes on the species known distributions, depth ranges, and habitats. There is also a brief account of the phylogeny of the group.
L J Cookson
Some observations on Chlorophora pilosus Forst. var. glabromaculatus Goeze (Coleoptera, Cerambycidae)
1980 - IRG/WP 1119
Über den Nagekäfer Oligomerus ptilinoides (Wollaston), Col., Anobiidae: Verbreitung und Einschleppung, Bestimmung, Lebens- beziehungen und Befallsmerkmale mit Vergleichen zu Nicobium
1980 - IRG/WP 1102
Oligomerus ptilinoides occurs in the Mediterranian and Black-sea area, in North-Africa and Asia minor as an important pest causing severe damage to dry wood. By travelling, by the immigration of people from south to north, and by accidental introductions the species tends to establish itself north of the Alps. Severe damage has recently been observed in two museums. An account is given of aspects of taxonomy, the pattern of attack compared with that of Nicobium hirtum and Nicobium castaneum, of the anatomy of the larvae, on symbiosis, and on behavioural features of the beetles.
Principles and procedure of the planeing test
1981 - IRG/WP 2162
Small end-sealed samples of pine-sapwood (1.5 x 2.5 x 5 cm³) are treated by brushing and afterwards different parts of the treated surface are removed. The remaining part of the sample is tested against either insects or fungi. If no attack occurs sufficient amounts of biocides have been penetrated at least beyond the zone which has been removed. In spite of some problems the test seems the only suitable method, to evaluate organic solvent preservatives, mainly those containing resins, for simple treating methods.
H Willeitner, M Gersonde
Cu, Cr and As distribution in soils adjacent to CCA treated utility poles in Eastern Black Sea Region of Turkey
2004 - IRG/WP 04-50214
In this study, the main objective was to asses the distribution of Cu, Cr, and As in soils adjacent to CCA treated utility poles in Eastern Blacksea Region of Turkey (Trabzon, Rize and Artvin ) and determine the influence of soil composition. Surface (0-5cm), subsurface soil samples (30-40cm) were collected near CCA-treated utility poles and control soil samples away from CCA-treated utility poles were also collected. Water holding capacity, pH, mechanical properties of soil samples were determined for both depth levels. Results showed that Cu, Cr and As concentration in soil samples taken from all three cities in 0-5cm depth was higher than soil samples taken from 30-40cm depth. Cu, Cr and As concentrations were much higher in soil samples taken from city of Rize.
E D Gezer, Ü C Yildiz, A Temiz, S Yildiz, E Dizman
Vertical distribution of fouling and wood-boring organisms in the Trondheimsfjord (Western Norway)
1981 - IRG/WP 467
Results of a detailed study on the vertical distribution of fouling and wood-boring organisms of Trondheimsfjord at an interval of 3 m from intertidal level to a depth of 30 m, has been presented, based on data collected from two series of panels, exposed from 15 March 1977 to 15 July 1977 (Series I) and from 22 July 1977 to 13 March 1978 (Series II). The intensity of fouling generally decreased with increasing depth. Quantitatively, fouling was heavy on panels of Series I more than on Series II, although species-wise it was more heterogenous on panels of Series II. The bulk of the fouling was constituted by Balanus crenatus, Laomedia sp., Mytilus sp., Modiolus sp. and Hiatella arctica. Incidence of borers and the resultant destruction of timber were heavier on panels of Series II than on those of Series I. The influence of the period of exposure on the above pattern of infestation by foulers and borers has been discussed. Psiloteredo megotara concentrated at the upper levels up to a depth of 15 m, with more settlement between 3 m to 9 m depth. Although Xylophaga dorsalis was present on panels from 3 m to 30 m depth, their intensity abruptly changed from 9 m onwards and continued to increase with increasing depth, with a maximum number near the mud level at 30 m. Attack of Limnoria lignorum also was heavy at the mud level. On the same panel, while Psiloteredo megotara preferred to settle in more numbers on the lower surface, Xylophaga dorsalis did so on the upper silted surface. The importance of such selective vertical incidence of different borers and their co-operation in the destructive activity have been stressed from the point of wood destruction in the Tronheimsfjord. The rate of growth of Balanus crenatus, Laomedia sp., Psiloteredo megotara, Xylophaga dorsalis, and Xylophaga praestans in relation to depth has been presented. For Balanus crenatus rate of growth decreased with increasing depth, while for Laomedia the same increas with depth up to 12 m and declined thereafter. In accordance with its depth preference, Psiloteredo megotara registered faster growth between 3 to 15 m depth. In the case of Xylophaga dorsalis, the size of the shell valve and burrow increased with increasing depth up to 24 to 27 m and then showed a slight decline at 30 m. Factors influencing the growth-rate at different levels have been discussed. The results on the vertical zonation and rate of growth of the wood-infesting organisms encountered, have been compared with relevant literature published earlier.
L N Santhakumaran
An investigation concerning Camponotus spp. distribution and damage in buildings in Sweden
1985 - IRG/WP 1248
This is a report of an investigation by a Swedish insurance company on the occurrences of damage by Carpenter ants during 1974 to 1981. The distribution of damage in walls, roofs and floors of both permanent homes and summer-houses has been assessed. It is concluded that the increased frequency of attack is becoming economically serious.
V Butovitsch, K-J Hedqvist, C Tornberg
Data sheet on woodboring insects. 1. Bostrychus capucinus (Linnaeus)
1979 - IRG/WP 193
A standardised procedure for the treatment of timber with test chemicals
1986 - IRG/WP 2257
A procedure is described which allows the standardisation of sample handling and data manipulation during trials invastigating the treatability of timber with test chemicals. The use of computer software allows the data to be handled efficiently.
J Norton, A Zosars, L E Leightley
Selective adsorption of antisapstain actives from two aqueous suspensions, and movement of actives into wood
1996 - IRG/WP 96-30103
Green-off-saw rough sawn Pinus elliottii (slash pine) boards were dipped in aqueous suspensions of two antisapstain formulations, NeXgenâ and Busanâ Sap Stain Preventative (Busan 1009), at three product concentration levels. Concentrations of active ingredients (NeXgen: CTL (chloro-thalonil) and MTC (methylene bisthiocyanate); Busan 1009: TCMTB (2(thiocyanomethylthio)-benzothiazole) and MTC) were monitored with respect to the amount of material dipped. Selective adsorption (removal of actives from the suspension at greater than simple volumetric transfer rates) varied with formulation and active ingredient, and increased with decreasing product concentration. Movement of active ingredients into dipped boards was monitored for 30 days after dipping. Mobility order was MTC >> TCMTB > CTL. Surface depletion characteristics were obtained for each active ingredient.
M J Kennedy, T L Woods
Studies of the distribution and degradation of tributyltin naphthenate in double-vacuum treated wood
1983 - IRG/WP 3230
The effects of forced solvent evaporation by kilning redwood (Pinus sylvestris) that has been double-vacuum treated with tributyltin naphthenate (TBTN) have been investigated. Contrary to previous studies reported, it has been shown that forced evaporation can have a considerable influence on the losses of the fungicide. It has been found that, whether the solvent is allowed to evaporate slowly or the evaporation is forced by kilning, the TBTN breaks down considerably in freshly treated wood. In view of the implications of this work for the long-term effectiveness of TBTN further studies are called for.
J Jermer, M-L Edlund, W Hintze, S V Ohlsson
Factors affecting leaching of preservatives in practice
1978 - IRG/WP 3113
At the 7th Meeting of the IRG in Poland in May 1975, the findings of collaborative laboratory leaching techniques were discussed, and the dangers inherent in using such results to predict the behaviour of preservative-treated components in service were emphasised. In order to improve our understanding of the factors governing leaching of preservatives in practice, and to identify areas where further research is required, it was agreed that a literature review should be prepared. This is presented below. Some points may be made regarding its format and content. First, the review shows that a large number of factors are of importance, including the properties of the wood, the leach water, the preservative and method of application and the nature of the environment to which the product is exposed. In many situations these factors interact and it is clearly impossible within the scope of this short paper to discuss all aspects of the problem in detail. However, the compilation of references will give ready access to the literature on particular topics. For ease of collation, the findings are discussed under a number of different headings. Secondly, less than one-third of the references cited deal with the results of service or field trials, while the others describe laboratory experiments designed to provide comparative data. The reservations expressed above concerning such small-scale experiments must be borne in mind when considering the validity of these findings. The information available on this topic up till 1964 was comprehensively reviewed by Wallace who identified and commented upon many of the factors discussed below. Her paper contained discussion on the performance of individual preservatives and on the mechanism of their fixation within the wood. These topics will not be considered here in any detail except insofar as they reflect general trends.
R Cockcroft, R A Laidlaw
Movement of boron from fused boron rods implanted in Southern pine, Douglas fir, red oak, and white oak timbers
1995 - IRG/WP 95-30061
This paper reports the distribution of boron from fused boron rods installed into six-inch (15.2 cm) square timbers of Douglas-fir, Southern Pine, red oak and white oak exposed aboveground. The composition and size of rods was: sodium borate and sodium borate-copper oxide (8.5 x 100 mm²); sodium borate-copper, sodium borate and boric oxide-copper oxide (12 x 76 mm²). The boric acid equivalent was roughly monitored by the curcumin/salicylic acid color test and the presence of copper was detected by the chrome azurol-S reagent. One year after installation of rods, movement of boron was determined by application of curcumin dye to increment cores removed at various distances from the site of boron rod installation. A portion of a sodium borate treated Southern Pine timber was also analyzed by spraying curcumin dye on sawed longitudinal and transverse sections. At 2 years, one foot sections were removed from all timber species, sawed as above, and boron and copper detection reagent sprayed on the sawed surfaces. Movement of copper from rods in all timbers was virtually nil. Both transverse and longitudinal movement of boron from rods was greatest in Southern pine which also had the highest moisture content. Movement of boron was next best in red oak. There was little movement of boron away from the rods in white oak and Douglas-fir.
T L Highley, L Ferge
Natural resistance of twenty-six Guianese wood species against marine borers
1988 - IRG/WP 4144
This note is a contribution on the study of the natural resistance of some wood species from French Guiana, some of which could be found too in the neighbourhood. Here are presented the results after one year exposure in the marine environment.
L N Trong
Geographical distribution of termites inside buildings in France
1991 - IRG/WP 1512
Since several years, data concerning infestations of buildings by termites are collected by CTBA. Most of them come from of the localizations communicated by the Pest Control Operators in the frame of the Approval. Maps were settled in 1975, 1981 and lastly in 1989. These maps show that the areas infested by termites are extending. Processing of data is described.
M-M Serment, A-M Pruvost