Your search resulted in 3115 documents. Displaying 25 entries per page.
Rapid loss of lignin at wood surfaces during natural weathering
1992 - IRG/WP 92-2390
Thin veneers of radiata pine (Pinus radiata D. Don) were exposed to natural weathering over a period of 30 days. Incident UV radiation was monitored at the test site. FTIR internal reflectance spectroscopy was used to study the chemical changes taking place at the veneer surface during weathering. Spectra obtained show that after only 3 days exposure there was substantial delignification at veneer...
P D Evans, K J Schmalzl, A J Michell
The comparative resistance to fungi of the wood munika (Pinus heldreichii Christ.), fir (Abies alba Mill.) and spruce (Picea excelsa Poir.) compared with Pinus sylvestris L. and some physical and mechanical characteristics of munika
1981 - IRG/WP 1129
The munika (Pinus heldreichii Christ.) is situated primarily in the Balkans, and partially in the south of the Apenine peninsula. As an endemic species, with a very little annual increment, it has not been used enough as a timber for mechanical conversion up till now, although the oldest trees can grow to 27 m in height, with a diameter at breast height of about 60 cm. According to data of many Ba...
M Petrovic, M Miric
Observations on the destruction of fishing craft in India by marine wood-borers with special reference to the West Coast
1981 - IRG/WP 468
The paper highlights the economic importance of the destruction of fishing craft in India by marine wood-destroying agencies. The annual loss involved is to the extent of over 94 million rupees. Thirty-nine spectes and one variety of woodborer have so far been recorded from India, of which Bankia campanellata, Bankia carinata, Bankia rochi, Dicyathifer manni, Lyrodus pedicellatus, Teredo clappi, T...
L N Santhakumaran, J C Jain
Assessing the importance of degradation mechanisms on the loss of effectiveness of wood preservatives
2000 - IRG/WP 00-20193
Accelerated ageing systems developed for application to samples in the laboratory prior to biological tests, should reflect those natural deterioration processes that are likely to occur in the hazard classes defined in EN 335-1. Losses through evaporation or the effects of leaching have been recognised, however their importance, relative to other mechanisms has not been quantified. Degradation me...
E D Suttie, R J Orsler, T Dearling
Nasutitermes exitiosus and wood-rotting fungi in Eucalyptus regnans, E. acmenioides, E. wandoo, and E. marginata: force-feeding, laboratory study
1985 - IRG/WP 1231
Under a force-feeding regime, the termitid Nasutitermes exitiosus was fed on four eucalypt timbers infested with several fungal species to investigate the influence of such fungus-infested timbers on mass of wood lost, termite biomass, fat content and water content. The results showed that wood mass losses were markedly affected by species of fungi and timber. The interaction of fungi and timbers ...
D B A Ruyooka
Wood decay of Pinus sylvestris L. and Fagus sylvatica L. by marine fungi. Part 2
1991 - IRG/WP 1471
The water-logged wood conservation requires a good knowledge of the wood decay organims which produce the degradation. Previous conducted studies (ESCORIAL, TROYA, GARCIA DE LOS RIOS, 1990) have shown that the incubation times normally used for in vitro laboratory tests are not sufficients for a significant wood degradation. This has been the reason why the aim of this work was the study of such d...
M T De Troya, A M Navarrete, M C Escorial
Silicon tetrachloride: A potential wood preservative
1980 - IRG/WP 3133
In its present form, this paper is a preliminary draft of a paper that will eventually be submitted for publication in the Forest Products Journal. We are continuing the work on the effects of silicon tetrachloride on wood and expect to have additional data for the meeting in May 1980. Specifically we are measuring the penetration rate and depth of SiCl4, and we are chemically analyzing the treate...
C W Owens, W T Shortle, A L Shigo
Estimation of mycelial biomass by determination of the ergosterol content of wood decayed by Coniophora puteana and Fomes fomentarius
1989 - IRG/WP 1415
The mycelial biomass of fungi decomposing wood materials may be estimated by the use of an ergosterol assay technique.ln decay tests, essentially according to EN 113, estimates made by HPLC analyses on wood decayed by Coniophora puteana and Fomes fomentarius show the increase in biomass in the wood blocks. The ergosterol contents were correlated with dry weight loss determinations. Degradation of ...
K Nilsson, J Bjurman
Influence of variable lignin content amongst hardwoods on soft-rot susceptibility and performance of CCA preservative
1982 - IRG/WP 1151
This paper presents the outline of an argument, based on both new and established data, which relates varying lignin content to variation of soft-rot susceptibility between hardwood species and of performance of CCA preservatives in controlling soft-rot. Although more data need to be generated to prove this relationship, sufficient evidence exists for the hypothesis to be given close attention, pa...
J A Butcher, T Nilsson
The loss of insecticidal action from synthetic pyrethroid-treated wood samples: The effect of high temperatures and relative humidities
1992 - IRG/WP 92-1569
This paper describes the results from bioassays using Hylotrupes bajulus, and chemical analyses, of pyrethroid-treated wood samples following storage for up to 3 years. A range of four storage environments was used consisting of combinations of two temperatures (20°C and 40°C) and two relative humidities (60% and 90%). It is concluded from the chemical analyses that, although losses at room temp...
R W Berry, S J Read
A quantitative weathering study of wood surfaces modified by chromium VI and iron III compounds
1989 - IRG/WP 2330
Thin veneers of Pinus radiata were treated with dilute aqueous solutions of chromium VI and iron III compounds and exposed to natural weathering for 35 days. Zero-span tensile strength and weight losses of treated veneers were compared with losses observed in untreated specimens In a study designed to demonstrate the applicability of strength and weight loss measurements to the rapid quantitative ...
P D Evans, K J Schmalzl
Control of wood biodeterioration by fungal metabolites
1992 - IRG/WP 92-1527
Treating wood with different conventional preservative chemicals for protection and economic utilisation is well known. Tough some of these chemicals are toxic to skin, their use as wood preservative is unavoidable as they should be toxic to biodeteriorating organisms also. Recent advances in chemistry of natural products enabled the use of wood extractives as biocidal compounds against biodeterio...
H S Ananthapadmanabha, H C Nagaveni, V V Srinivasan
Observations on the destruction of fishing craft in India by marine wood-borers with special reference to the West Coast
1981 - IRG/WP 472
The paper highlights the economic importance of the destruction of fishing craft in India by marine wood-destroying agencies. The annual loss involved is to the extent of over 94 million rupees. Thirty-nine spectes and one variety of woodborer have so far been recorded from India, of which Bankia campanellata, Bankia carinata, Bankia rochi, Dicyathifer manni, Lyrodus pedicellatus, Teredo clappi, T...
L N Santhakumaran, J C Jain
Preliminary investigation on the natural durability of Guayule (Parthenium argentatum)-based wood products
2000 - IRG/WP 00-40154
Conventional preservatives used to protect wood from insect and microbial damages are presently of major concern to human health and the environment. Finding alternative and economical preservatives has not been successful. Previous studies have shown that the resinous material extracted from the guayule plant (Parthenium argentatum, Gray) has both insect- and microbial-resistant properties. Unfor...
F S Nakayama, P Chow, D S Bajwa, J A Youngquist, J H Muehl, A M Krzysik
List of fungi in soft-rot tests
1975 - IRG/WP 105
This list gives information on the terrestrial and marine species and strains of fungi tested for soft-rot ability in pure culture with data on their decay activity in untreated wood. An index of the timber species tested is added. The compilation is based on 1) the list of soft-rot fungi of the former OECD Group (Doc.No. 27/DAS/CSI/M/559), Oct. 1968, prepared by R. Rösch and W. Liese, 2) informa...
G Seehann, W Liese, B Kess
Determination of toxicity data for preservatives against Basidiomycetes by measuring the reduction in compression strength of wood
1988 - IRG/WP 2297
Blocks of Pinus radiata D. Don were treated to 12 retention levels with CCA and NaPCP. These were exposed for 12 weeks in agar jars to the dry rot (brown rot) Serpula lacrymans (Schum. ex Fr.) S.F. Gray. After mass loss determination, the same blocks were tested for reduction in compression strength parallel to the grain. Using both these parameters, together with interpolated 6 week strength loss...
J Wazny, J D Thornton
Influence of the content of organic matter of soil on the degradation of wood by soft rot fungi
1970 - IRG/WP 27
The degradation of wood specimen burried in the soil by soft rot fungi is influenced by a number of factors. These are in particular the water holding capacity, water content, content of organic matter, pH, content of mineral nutritive substances etc. The results of the interlaboratory tests, carried out within the IRG/WP let presume that the intensity of wood degradation occurs proportionally inv...
O Wälchli
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
Effects of heart wood extractives in Dahoma (Piptadeniastrum africanum) on decay resistance to white- and brown-rot fungi
2004 - IRG/WP 04-10536
Dahoma (Piptadeniastrum africanum) is a durable but a lesser utilised tropical hardwood species from Ghana that has the potential of being used as an alternative to Iroko (Milicia excelsa) for many end uses. However, the timber gives off a strong odour especially when wet and during processing. The high durability and the strong odour of the timber could be due to the presence of extractives in th...
Zeen Huang, K Maher, S A Amartey
Correlation between modulus of elasticity, mass losses and FTIR spectra of copper treated decayed wood
2006 - IRG/WP 06-10580
The composition of copper-based preservatives will change from copper-chromium to copper-ethanolamine, due to environmental demands. The most important drawback of copper-impregnated wood is the presence of tolerant fungal organisms that have developed an ability to degrade such preserved wood. In order to elucidate these processes, specimens (0.5×1.0×15 cm) made of Norway spruce (Picea abies) w...
M Humar, B Bucar, F Pohleven
Time-of-Flight Secondary Ion Mass Spectrometry Analysis of Polyethylene Glycol Penetration into Wood Cell Walls
2006 - IRG/WP 06-20328
Penetration of high molecular weight polyethylene glycol (PEG) into wood cell walls was investigated in red pine. PEG of different molecular weights (1000, 8000 and 20000) was labelled by bromination and treated samples were analyzed on Time-of-Flight Secondary Ion Mass Spectrometry (TOF-SIMS) in dynamic mode. Both negative and positive spectra of the samples were collected in high spatial (bunche...
D Jeremic, P Cooper, P Brodersen
Quantitative and qualitative losses in wood of oriental spruce, Picea orientalis (L.) Link., induced by insects from forest to utility
2008 - IRG/WP 08-10647
In this study, some quantitative and qualitative losses in wood of oriental spruce, Picea orientalis (L.) Link., induced by insects from forest to utility were evaluated. In experimental plots, volume of trees damaged by Dendroctonus micans (Kug.) was 34% of the volume of total standing spruce trees in the oriental spruce forests of Turkey. The volume of standing trees that D. micans damaged was ...
H A Akinci, M Eroglu, G E Özcan, Ü C Yildiz
Natural durability of different wood species in above ground applications - Weight and MOE loss
2008 - IRG/WP 08-10667
In Norway, exterior wood structures have traditionally, nearly exclusively been made of untreated Norway spruce (Picea abies (L.) Karst) and pressure treated Scots pine (Pinus sylvestris L.). In recent years there has been a tendency that other wood species, like various Norwegian hardwoods or imported species, have been used in exterior above ground applications, often not surface treated. For se...
F G Evans, P-O Flæte, G Alfredsen
Mechanical strength of wood from the Vasa shipwreck
2008 - IRG/WP 08-20381
Samples from three ancient ship wrecks (Vasa, Elefanten, and Gröne Jägaren) and recent oak samples as reference were examined with regard to mechanical strength using the high-energy multiple impact (HEMI) - test method, which delivers the resistance to impact milling (RIM) of a material. Adoption and optimisation of the test method for the particular sample size of the wooden drilling cores was...
A O Rapp, C Brischke, C R Welzbacher, T Nilsson, C Björdal
Treatment of Selected Lesser Used Timber Species against Subterranean Termites using Heartwood Extracts from Teak (Tectona grandis) and Dahoma (Piptadeniastrum africanum)
2008 - IRG/WP 08-30476
Lesser used timber species represent a valuable material for all-purpose uses. However, most of them are not durable. They are, for effective utilization, often treated with all manner of toxic synthetic substances to enhance their natural durability, especially in the tropics where conditions favour their deterioration. Most of these toxic synthetic substances often pose a threat to the environme...
A Asamoah, C Antwi-Boasiako, K Frimpong-Mensah