Your search resulted in 233 documents. Displaying 25 entries per page.
Differential behaviour of wood rotters at water repellent Rubberwood
2000 - IRG/WP 00-10386
Rubberwood samples treated with different concentration of aqueous solution of chromic acid has induced significant increase in water repellency and attains dimensional stability. Though water repellency and dimensional stability was achieved by treatment, the fungal invasion could not be completely controlled. Differential level of decay of brown and white rot in wood treated with water repellent...
H C Nagaveni, S S Chauhan, K S Rao
Life cycle analysis: Assessing environmental impact
1994 - IRG/WP 94-50034
Environmental impact assesment is a major issue that faces every nation today. However, consistently and objectively measuring the environmental impact is difficult. During the past two decades, a process called life cycle analysis was developed that tried to make consistent and objective environmental assessments. The Society of Environmental Toxicology and Chemistry broadened the concept to not ...
S L LeVan
Ground contact performance of wood treated by the MSU process
1990 - IRG/WP 3609
Environmental concerns have prompted a renewed interest in accelerated fixation schemes for CCA-treated wood. Results from stake tests of southern pine (Pinus sp.) treated using a conventional Bethell cycle are compared with matched stakes treated using the MSU Process. The effects of adding boric acid to the preservative formulation are also discussed. Differences among test plots are discussed....
H M Barnes, T L Amburgey, R W Landers
Investigations on the life cycle and nutrition of Criocephalus rusticus L
1974 - IRG/WP 127
The longhorn beetle Criocephalus rusticus L or Arhopalus rusticus (L) is widely distributed in Europe and Asia. It attacks softwoods. The primary host trees are pines, ie freshly felled, unbarked logs, dying standing trees and stumps. After feeding under the bark the larvae enter the sapwood and also the heartwood. Timber to be used for building purposes may be rendered useless by their tunnelling...
H Kühne
Life cycle analysis of utility poles. A Swiss case study
1995 - IRG/WP 95-50040-05
Use of preservative-treated wood products faces increasing public and political pressure because of environmental concerns regarding the chemicals used to protect the wood. However, critics usually focus only on one single aspect of the whole life cycle of treated wood products, disregarding other environmental effects of timber utilization. To evaluate the ecological consequences of wooden utilit...
T Künniger, K Richter
Waste management of wood products in life cycle assessment
2000 - IRG/WP 00-50154
Within the framework of the European project LIFE SYS WOOD (contractnr. FAIR CT95-7026) TNO has performed a study on the waste management of wood demolition waste for inclusion in Life Cycle Assessment. In LIFE SYS WOOD one of the main aims was to develop a consistent LCA methodology for wood products. LCA case studies have been performed by partners on wood as raw material, glulam contructions, O...
P Esser, P Eggels, A Voss
Iron in stone wool - one reason for the increased growth and decay capacity of Serpula lacrymans
1992 - IRG/WP 92-1537
The chemical compositions of stone wool and glass wool were analysed. There was more iron in the stone wool than in the glass wool. It was found that iron present in stone wool was easily dissolved by oxalic acid that Serpula lacrymans is able to produce. The stone wool promoted the decay of pine wood by Serpula lacrymans. The glass wool had no effect on the decay capacity of Serpula Iacrymans. Th...
L Paajanen, A-C Ritschkoff
The performance of water repellants on radiata pine exposed to the weather
1989 - IRG/WP 3553
The effectiveness and resistance to weathering of four water repellent treatments, a commercial timber stain, and an oil-based clear finish, was assessed using 20x20x6 mm³ samples of untreated, copper-chrome-arsenic (CCA)-treated, and tributyltin oxide (TBTO)-treated radiata pine exposed to the weather over a four month period. The water repellency of each preservative/water repellent combination...
D V Plackett, F M Cameron
Effects of Trichoderma harzianum on enzyme activity and oxalic acid production of Gloeophyllum trabeum in ponderosa pine sapwood blocks
1992 - IRG/WP 92-1550
The effect of a bioprotectant, Trichoderma harzianum, on the activity of Gloeophyllum trabeum was investigated using a wood wafer sandwich method. Wood weight loss was greatest with Gloeophyllum trabeum exposed wafers, intermediate with those exposed to both the bioprotectant and decay fungus, and lowest with the bioprotectant exposed wafers. Extracts of wood wafers after 2, 4, or 6 weeks of funga...
C M Sexton, J J Morrell
Vapour boron treatment of wood based panels: Mechanism for effect upon impact resistance
1994 - IRG/WP 94-40036
Samples of medium density fibreboard, chipboard and oriented strandboard (OSB) were treated to two retentions of boric acid by a vapour phase treatment. The results of a range of mechanical tests were reported by Hashim et al. (1992, 1993) in which a small reduction in impact resistance was observed. Several investigations were carried out to study how and where this loss in impact resistance occu...
R Hashim, R J Murphy, D J Dickinson, J Dinwoodie
Sterilization of mango wood (Mangifera indica L.) without heat
1995 - IRG/WP 95-30065
Researches revealed that boric acid can play an important role for sterilizing wood instead of heating. Wet (green) mango boards (Mangifera indica L.) were pressure treated in treating cylinder at initial vacuum of 508 mm Hg for 15 minutes and impregnation pressure of 7 kg/cm² for 4 hours with 5% solution (w/v) of 1:1:1 commercial grade (95% pure) sodium dichromate, copper sulphate and boric acid...
A K Lahiry
The reliability of colouring methods for the determination of biflourides and boron in spruce wood
1994 - IRG/WP 94-20036
From practical reasons, qualitative spraying methods are widely used for the detection of bifluorides and boron in wood. The main aim of this research was to detect whether the concentration of the active ingredient in the coloured area is equal or greater than the toxic value against basidiomycetes. Both colouring methods, Z-A reagent for fluorides and curcuma reagent for boric acid, are a reliab...
R Grell, M G Sanders, W J Homan, H Militz
Oxalate production and calcium oxalate accumulation by Gloeophyllum trabeum in buffered cultures
1994 - IRG/WP 94-10075
Most basidiomycetous fungi produce oxalic acid as a result of their metabolic activities and nutrient procurement. There is currently a renewed interest in the role that oxalic acid may play in the decomposition of wood by basidiomycete fungi. It has been observed that although most wood degrading fungi have the capacity to produce oxalic acid, not all of these organisms express this capacity equa...
J H Connolly, J Jellison
Leaching results of shower test on L-joints with boric acid, bifluoride and TBTO rods
1995 - IRG/WP 95-50051
As part of the EC-project "Improvement of a local preservation process for wood products with reduced environmental impact", TNO has performed a leaching test on L-joints treated with pills with boric acid (Defence corner), bifluorides (Woodpil 55) and TBTO (Woodcap). The L-joints were exposed in an adapted shower test during 10 days, using 70 liters of water per day. The experiment is designed to...
P Esser, M J Boonstra, W L D Suitela, A J Pendlebury
Bioefficacy of boric acid grafted onto wood
1999 - IRG/WP 99-30202
The use of borate treated wood in outdoor is limited because of the migration of borate. The objective of this study is to investigate the fixation of boric acid in wood using polyethylene glycol (PEG-400) to form polyester borate and isocyanato group as coupling agent. FT-IR was used to monitor the reaction between boric acid and PEG. Elemental analysis was conducted to evaluate the C, H, and N v...
Weining Cui, D P Kamdem
Treatment of wood-based panel products with volatile borate
1990 - IRG/WP 3616
The paper presents recent developments in the use of volatile borate esters for the preservative treatment of wood based board materials. Several advances on previous reports are discussed. In laboratory studies, treatment times of approximately ten minutes at 20°C on boards at equilibrium moisture content provided full penetration and retentions of 1% wt/wt boric acid. Biological tests have been...
P Turner, R J Murphy, D J Dickinson
Identification of terminal structures in cellulose degraded by the brown-rot fungus Postia placenta
1989 - IRG/WP 1389
To gain insight into the biochemical mechanism employed by brown-rot fungi to depolymerize cellulose, we identified the end-groups of chemically pure cellulose that had been depolymerized by the brown-rot fungus, Postia placenta. The depolymerized cellulose was acid hydrolyzed and the anion fractions isolated by ion chromatography. Sugar acids were identified by gas chromatographic and mass spectr...
T K Kirk, T L Highley, R E Ibach, M D Mozuch
Efficacy of linear chain carboxylic acid anhydrides as wood protection chemicals
2002 - IRG/WP 02-30295
This paper presents an assessment of the effectiveness of linear chain carboxylic acid anhydrides namely, acetic, propionic, butyric, valeric and hexanoic anhydride, in improving the decay resistance of Corsican pine (Pinus nigra Schneid) sapwood. Wood-anhydride bond formation was verified by the increase in sample weight and volume. A brown rot fungus
[Coniophora puteana (Schum.:Fr)] was selec...
A N Papadopoulos, M D C Hale, C A S Hill
Treatment of wood with formaldehyde. Acid catalysis of the reaction between formaldehyde and wood
1980 - IRG/WP 3146
Formaldehyde reacts with the free OH-groups in wood forming cross-linking bonds. The reaction can be brought about without any catalyst but in that case the activation energy is very high and high temperatures and long reaction times are needed. Normally, the reaction is catalysed by different acids. Acid catalysts, however, tend to degrade the cellulose and the wood matrix causing reduction in th...
T Vihavainen, K Piispanen, P Mansikkamäki
Summaries of two Russian papers received from Professor Dr. D.A. Belenkov and V.A. Seletskaya of the Ural Forest Engineering Institute, Sibirsky Trakt, 37, Sverdlovsk, USSR, on the toxicity to Coniophora cerebella of salts of hydrofluoric acid and some fluoroborates
1977 - IRG/WP 298
1) Evaluation of the toxicity of some salts of hydrofluoric acid against the house cellar fungus (Coniophora cerebella Schroet)
Data are presented on the method of probability evaluation of the toxicity of the fluorides of sodium, ammonium, potassium, zinc and iron. On the retention of fluorine in wood all salts, except iron, possess practically equal toxicity at the standard level of the probability of the protection of the wood - 0.95 . There is good agreement between the analytically and graphically determined dose level. Evidence is given for dose variabitility, probabilities of wood protection at 0.5 and 0.95, the curve of efficacy - activity and the construction of the empirical probit graph.
2) Investigation of the toxicity of some borofluorides towards the house cellar fungus
Probability evaluation of the toxicity of borofluorides against the cellar fungus, and probit analysis evidence show that toxicity decreases in the sequence sodium borofluoride, copper borofluoride, tributyltin borofluoride. The effectiveness of protection method is able to evaluate the amount of fluorine and boron required in the wood.
C Grant
Copper naphthenate: An analysis of the materials found in the worldwide marketplace using a new analytical technique
2000 - IRG/WP 00-30224
Naphthenic acid has been recovered from products of petroleum refining for well over 100 years. The metal soaps, specifically copper and zinc naphthenate, have been evaluated and used as commercial wood preservatives for in excess of 60 years. Most of the early data supporting the continued use of copper naphthenate as a wood preservative was based on materials manufactured from naturally occurrin...
J A Brient, R E Moyer, M H Freeman, H Jiang
Microscopical analysis of formaldehyde-acid modified wood
1981 - IRG/WP 3182
Cross-linking of wood with gaseous formaldehyde improves its hygroscopic and dimensional behaviour, and its resistance against micro-organisms. However, formaldehyde cross-linking reactions take place only in the presence of an acid catalyst, which results in losses in mechanical By optimization of a formaldehyde-sulfur dioxide vapour phase process the reaction conditions were established to limit...
M Stevens, N Parameswaran
The efficacy of remedial treatments for controlling fungal decay in window millwork used in the United States
1987 - IRG/WP 3432
Conventional window millwork was subjected to basidiomycete decay by inoculation and sampled for active growth of the decay fungus before and eight months after remedial preservative treatment with fused disodium octaborate rods (IMPEL) at boric acid levels of 1.5 and 4.0 kg/m³ or liquid bifluoride injections (IMPROSOL) at 1 kg/m³. The elimination of decay fungus after remedial treatment was nea...
M G Dietz, E L Schmidt
Incorporation of phenyl boronic acid treatment with vapor phase formalization
1997 - IRG/WP 97-40083
Phenylboronic acid (PBA) treatment was incorporated with vapor phase formalization (VPF) in order to increase dimensional stability and boron fixation as well as enhancement of biological resistance. Five and ten hours VPF were applied after PBA treatment as 0.34, 0.50, 1.00 and 2.00% concs. aqueous solutions. Anti swelling efficiency (ASE) attended to 71% in specimens impregnated with 0.50% PBA s...
M K Yalinkilic, S Yusuf, T Yoshimura, W-Y Su, K Tsunoda, M Takahashi
Life-cycle assessement of treated wood: A view from the roa
1996 - IRG/WP 96-50078
Life Cycle Assessement (LCA) is being used increasingly as a tool to structure information on the environmental characteristics of material and processes. This paper is based on the experience gained from our LCA studies on treated wood products over the last 4 years. The comprehensive and logical examination af the information available on treated timber provided by LCA has allowed identification...
W Hillier, R J Murphy, D J Dickinson, J N B Bell