Your search resulted in 332 documents. Displaying 25 entries per page.
The effects of preservative treatment and exposure to wood degrading fungi on fiber reinforced polymer (FRP) materials used for structural wood reinforcement
2001 - IRG/WP 01-40204
Glass fiber reinforced phenolic (GFRP) composite materials are becoming increasingly accepted for use in the construction industry because they combine advantages of both wood and advanced polymeric materials. Addition of only 1-3% FRP in the tension zone, for example, can typically improve the strength of the hybrid system by 200%. As more applications are found for wood/FRP hybrids, (e.g. lamina...
C Tascioglu, B Goodell
Research studies on infecting behaviour of Fomes fomentarius (L. ex FR) Fr. and its physical control in the wood yards of the Hyrcanian (Caspian) forests of Ira
1996 - IRG/WP 96-10179
Due to illegal cutting, girdling and ringbarking many damages of tinder fungus (Fomes fomentarius (L. ex Fr) Fr.) are seen on beech, poplar, oak and birch at Hyrcanian (Caspian) forests of Iran. The beeches (Fagus orientalis Lipsky) are damaged highly and the beech community of Fagetum are infected from 800 meter altitudes at Gorgan (East of Caspian forests) to 600 meters altitudes at Gilan (West ...
P Niloufari
Glass splinters as physical termite barriers: Optimized material properties in use with and without insecticidal pretreatment minimizes environmental contaminations
1991 - IRG/WP 1476
The major advantage of physically acting barriers against termites using sand or cinder is to be impenetrable for a number of termite species by showing environmental compatibility in a high degree. The major disadvantage of these barriers is the ability of termites to build galleries over them. Glass or glass-like materials are showing optimum material properties: crushed to a particle size from ...
M Pallaske, A Igarashi
Biological and physical properties of phenolic-resin treated wood before and after natural weathering
1999 - IRG/WP 99-40132
Biological and physical properties of phenolic resin-treated particleboards, which were made from fast growing tress and agrowaste as raw materials, were evaluated before and after natural weathering in tropical climate. The particles were sprayed with a mixture of a low molecular weight phenol-formaldehyde resin (5.0, 7.5 and 10% loading) and the adhesive phenol resin (8% loading). Results with l...
S Yusuf, Y Sudiyani, H Kajita, Y Imamura, M Takahashi
Prevention of non-microbial sapwood discolorations in hardwood lumber: chemical and mechanical treatments
1997 - IRG/WP 97-30137
Sapwood discolorations in hardwood lumber that are non-microbial in origin result from the formation of pigmented starch-like granules in ray parenchyma cells. These discolorations can be prevented by treating unseasoned lumber with an antioxidant (sodium bisulfite). Exposing unseasoned lumber to microwaves or treating logs with fumigants also will prevent these discolorations. Subjecting unseason...
T L Amburgey, S Kitchens
The kinetics of anhydride modification reactions of wood. Experimental results and theoretical modelling
1998 - IRG/WP 98-40125
Although the chemical modification of wood remains a fertile area for research, there has been little work performed on the kinetics of the modification process. The reaction kinetics of a series of linear chain and cyclic anhydrides has been studied and activation energies of the reaction determined. The reaction kinetic profiles are determined by the relative rates of reaction of the reagent wit...
C A S Hill, J G Hillier
Physical and mechanical properties of tea (Thea sinensis L.), kanak chura (Peltophorum pterocarpum (DC.) Baker ex Heyne ) and bottle brush (Callistemon citrinus Stapf. ) - Timbers grown is Bangladesh
1999 - IRG/WP 99-40141
The physical and mechanical properties, especially the strength, density, structure, colour, natural durability, workability, seasonableness and treatability of timbers of tea (Thea sinensis), kanak chura (Peltophorum pterocarpum) and bottle brush (Callistemon citrinus) grown in Bangladesh have been found out for the first time. The tea and bottle brush are completely treatable at dry condition an...
A K Lahiry
Effects of chemical pretreatment of Douglas-fir heartwood on efficacy of potential bioprotection agents
1990 - IRG/WP 1440
Biological protection against wood decay fungi represents an environmentally attractive alternative to the use of chemicals; however, the process of identifying suitable candidates and the conditions that ensure successful protection pose major challenges. One critical aspect of this problem is to identify organisms that can rapidly and uniformly colonize the wood. Wood contains low levels of nutr...
B Dawson-Andoh, J J Morrell
Biological and chemical investigations for the assessment of the environmental impact of wood preservative components
1999 - IRG/WP 99-50127
This study was carried out in order to investigate the suitability of biological and chemical techniques to evaluate the environmental impact of wood preservatives depleted from impregnated wood. Small specimens (15*25*50 mm3) of Scots pine sapwood (Pinus sylvestris) were treated with a CCB salt. After fixation the treated and untreated samples were washed-out according EN 84, and the different le...
E Melcher, H-W Wegen
Modification of solid wood: research and practical potential
1997 - IRG/WP 97-40098
The polymeric structure of the wooden cellwall mainly consists cellulose, hemicellulose and lignin. The most reactive sites on these components are the hydroxyl groups. The cellwall polymers (and its reactive hydroxyl groups) are responsible for most physical and chemical properties of wood. By changing the basic chemistry of the cellwall polymers, it is possible to change different undesirable at...
H Militz, E P J Beckers, W J Homan
Chemical treatment of chips for outdoor storage. Evaluation of sodium N-methyldithiocarbamate + sodium 2,4-dinitrophenol treatment
1980 - IRG/WP 2134
Fresh slash pine chips were treated by spraying them with a dilute aqueous solution of sodium N-methyldithiocarbamate and sodium 2,4-dinitrophenol. The were then formed into an experimental chip file 10 feet high, and the pile was maintained for seven months. The treatment effectively slowed heat release and retarded losses in wood substances, tall oil, pulp yield, and pulp strenght. Under certain...
E L Springer, M Benjamin, W C Feist, L L Zoch, G J Hajny
Biological degradation resistance of wood acetylated with thioacetic acid
1983 - IRG/WP 3223
Chemically, modification of wood is being considered as an alternative to conventional preservation by toxic chemicals. Acetylated wood has been reported to be quite resistant to most biodegrading organisms at weight percent gains (WPG) around 15-19. The conventional acetylation techniques with acethic anhyrdride result in generation of acetic acid. However, acetylation with thioacetic acid overco...
S Kumar, S C Agarwal
Three years of field tests with "Lignomer" stakes in ground contact
1981 - IRG/WP 3166
The "Lignomer" (Wood Polymer Composite) is a material obtained during the polymerisation of various monomers or its mixtures in wood. As laboratory tests have shown, this material is characterized by a high resistance against biological deteriorating agents. The laboratory investigations on the durability of various materials against biological deterioration are in many instances extended by field...
K Lutomski
Influence of the decay of spruce chips by the selected fungi on their chemical structure and the pulp properties
2004 - IRG/WP 04-10510
The paper focuses on changes in the weight and in the molecular structure of spruce chips submitted to long-term storing as well as to medium- and long-term model rotting degradation caused by some chosen fungi identified at storing processes on the pile. For the model decay of chips under laboratory conditions during 3 or 6 weeks the white-rot fungi: Phanerochaete chrysosporium, Heterobasidion an...
R Solár, L Reinprecht, A Geffert, F Kacík
Decomposition of biocides in aqueous media cases of MTC and TCMTB
1993 - IRG/WP 93-50001-26
Our laboratory is interested in the fate of modern biocide molecules in the environment. Here we present recent work which has been done on the fate of two compounds with fungicidal and bactericidal properties: methylenedithiocyanate (MTC: NCS - CH2 - SCN) and thiocyanomethylthiobenzothiazol (TCMTB). We have studied separately the influence of pH, temperature and ultraviolet irradiation in aqueous...
R Perraud, M Papazian
Chemical and biological investigations of double-vacuum treated windows after 7½ years in service
1985 - IRG/WP 3339
Earlier investigations of double-vacuum treated windows after five years in service have shown that tributyltin oxide (TBTO) degrades to di- and monobutyltin compounds and that the resistance of the wood against decay decreases. An investigation 2.5 years later of the same windows shows that the degradation of TBTO proceeds fast. After 7.5 years in service only 15-35% of the remaining organotin co...
M-L Edlund, J Jermer, B Henningsson, W Hintze
Changes in some important mechanical and physical properties of untreated and treated mining timber after exposure to the conditions of a colliery
1996 - IRG/WP 96-20082
Each of salt treated and untreated mining timber (wedge) pairs with 5x15 cm² cross-section and 155 cm length prepared from Scots pine, Bornmüller's fir and oriental beech was cut in the small standard test specimens to determine changes in some important mechanical and physical properties, 13 month after exposure to the conditions of Kozlu Hard Coal Mines in the depth of 52 m. Thus, the...
A Bobat
Chemical analysis of wood waste - The problem of sampling
1999 - IRG/WP 99-20168
A quantitative analysis of the content of active substances in wood is often demanded in quality control after processing and for the proper waste management. As a measure for quality control, analysis has the advantage that the type of preservative is known and assumptions can be made about its distribution in the treated wood.W aste wood may have been treated by a wide range of organic and inorg...
A Peylo, R-D Peek
Screening of the technical performance and aquatic toxicity of N-methylolacrylamide treated wood
2000 - IRG/WP 00-40166
In the course of the last decades chemical modification of wood species, with a limited natural durability, has been subjected to intensive research. As a possible alternative and supplementary treatment of non-durable wood in a range of applications it remains one of the major topics in the wood preservation world. Different modification systems have been scaled-up and are now in an industrialisi...
V Rijckaert, S De Geyter, J Van Acker, M Stevens
Micromorphological and chemical changes of archaeological woods from wrecked ship's timbers
1987 - IRG/WP 4136
Micromorphological and chemical alterations of sea-waterlogged woods obtained from the ship-wrecked materials which had been submerged in Yellow Sea for over 700 years were investigated. The woods were deteriorated in varying degrees by marine organisms depending on species and parts of the woods. Under the light and scanning electron microscope the morphological characteristics of deteriorated wo...
Y S Kim
Effect of fungal degradation on the chemical composition of acetylated beech wood
2003 - IRG/WP 03-40267
This study investigated the impact of fungal attack on the chemical composition of acetylated wood. Beech wood acetylated to different degrees was exposed to decay by the white-rot fungus Trametes versicolor under solid-state fermentation conditions. Laboratory soil-bed assays were also conducted to study the degradation of acetylated wood by soft rot fungi and other soil-inhabiting microorganisms...
H Militz, Dong-won Son, L Gómez-Hernández, R Sierra-Alvarez
Quantification of creosote migration down wooden poles and the prevention of its depletion during flood irrigation
1994 - IRG/WP 94-50032
Polyethylene field liners heat-shrunk onto soil-contact surfaces prevented decay of creosote-treated Eucalyptus grandis vineyard poles under flood-irrigation. The present work quantified losses of creosote from these poles after six and 24 months' service. After six months' service the mean creosote retention of unlined poles above the ground line was 12.62% (m/m dry wood), with ...
M Behr, A A W Baecker
A 53-year old field trial to evaluate the performance of a range of chemical treatments on eucalypt poles
1989 - IRG/WP 3526
Hardwood pole stubs of Eucalyptus maculata, Eucalyptus pilularis, Eucalyptus saligna and Eucalyptus paniculata were examined for termite attack and fungal decay after 53 years in ground contact. The trial compared eight different chemical treatments with untreated pole stubs of the four species investigated. Untreated Eucalyptus paniculata, a Class I durability species, performed particularly well...
R S Johnstone, R A Eaton
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
Development of a commercial-scale CCA chemical sludge recycling system
1993 - IRG/WP 93-50001-19
The occurrence of fixation reactions in Copper Chromium Arsenate (CCA) treatment solutions is increased where the treatment of unseasoned and partially seasoned timbers in hot climates occurs. The by-products of the fixation reactions are predominantly insoluble chromium arsenate compounds, commonly referred to as CCA sludge. Historically, this material has been disposed of into toxic waste landfi...
A J B Butler