Your search resulted in 62 documents. Displaying 25 entries per page.
An insight into brown rot decay of timber as revealed by 13C CP/MAS NMR
1985 - IRG/WP 1259
L E Leightley
The use of C CP/MAS NMR in the chemical identification of decayed and undecayed, tropical timber species
1984 - IRG/WP 1224
13C CP/MAS NMR was found to be an extremely powerful tool for elucidating the chemical composition of Eucalyptus maculata, Pinus elliottii and Alstonia scholaris. The differences in lignin composition were different for each timber and discussed in relation to decay caused by soft-rot and white rot fungi. In particular the presence of syringyl and guaiacyl lignin types are discussed.
L E Leightley
Effect of wood polymers degradation during heat treatment on extracellular enzymatic activities involved in beech degradation by Trametes versicolor
2008 - IRG/WP 08-40392
Effect of heat treatment on extracellular enzymes involved in wood degradation by Trametes versicolor was investigated. Heat-treated and untreated beech blocks were exposed to T. versicolor on malt agar medium and extracellular enzymatic activities investigated. A strong ABTS oxidizing activity has been detected during the first stage of colonization in both cases, while cellulase activities are m...
S Lekounougou, G Nguila Inari, M Pétrissans, S Dumarçay, J P Jacquot, E Gelhaye, P Gérardin
Characterisation and evaluation of various chitosan oligomers, and decay resistance
2011 - IRG/WP 11-30562
Chitosan, a polymer of D-glucosamine, is known for its antimicrobial activity. However, the physicochemical properties of chitosan depend upon three principal factors, i.e. source of raw material, molecular weight and degree of deacetylation. Here, we report synthesis and characterization of chitosan oligomers prepared by deaminative depolymerization of chitosan (s) obtained from Sigma Aldrich and...
I Hussain, C Chittenden, T Singh
Effect of acetylation on decay resistance of wood against brown-rot, white-rot and soft-rot fungi
1989 - IRG/WP 3540
Effect of acetylation on decay resistance of wood was investigated using wood blocks of Cryptomeria japonica, Pinus densiflora, Albizia falcata and Fagus crenata. Blocks were treated with uncatalyzed acetic anhydride for different lengths of time and exposed to Tyromyces palustris, Serpula lacrymans, Coriolus versicolor and unsterilized soil. The action of OH-radical on acetylated wood was also ex...
M Takahashi, Y Imamura, M Tanahashi
Preliminary observations on tributyltin treated Scots pine sapwood using 119Sn (Mössbauer and NMR) spectroscopic techniques
1984 - IRG/WP 3312
119mSn Mössbauer data are presented for bis(tributyltin) oxide, tributyltin ethanesulphonate, bis(tributyltin) carbonate and tris(tributyltin) phosphate, both in the pure form and in Scots pine sapwood. The structures proposed for these compounds, in the solid state, are supported by 119Sn nuclear magnetic resonance spectroscopy.
R Hill
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
Preliminary study of the fungicidal and structural variability in copper naphthenates and naphthenic acids
1996 - IRG/WP 96-30114
Copper naphthenates, an oil-borne wood preservative listed by the American Wood-Preservers' Association (AWPA), is manufactured by complexing copper(II) with naphthenic acids. Prior to AWPA listing as a wood preservative, field experiments showed that copper naphthenates generally had good stability and were active against wood-destroying organisms. Recently, however, there have been reports ...
T Schultz, D D Nicholas, L L Ingram Jr, T H Fisher
An investigation into the stability of TBTO in LOSP-treated radiata pine
1987 - IRG/WP 3459
Nuclear magnetic resonance (NMR) spectroscopy and reverse phase paper chromatography were used to characterise the organotin compounds found in radiata pine treated with bis (tri-n-butyl) tin oxide (TBTO). Preliminary results indicate that the preservative is remarkably unstable in wood after light organic solvent preservative (LOSP) treatment. Significant decomposition of TBTO occurs in a matter ...
K J Archer, R Meder
The formation of organotin carboxylates in bis(tributyltin) oxide - treated Pinus sylvestris sapwood
1990 - IRG/WP 3618
Tributyltin compounds have been successfully used for many years as wood preservatives, although their chemical nature in timber have not been fully elucidated. This study by 119Sn and 13C NMR spectroscopy has shown that, on impregnation into Pinus sylvestris sapwood, bis(tributyltin) oxide, (Bu3Sn)2O, is rapidly converted to tributyltin carboxylates, Bu3SnOCO·R, via reaction with components of t...
S J Blunden, R Hill
Extracellular layers of wood decay fungi and copper tolerance
1983 - IRG/WP 1180
Extracellular layers around the hyphae of brown, white and soft rot fungi have been examined using electron microscopy. These layers were isolated for identification. Particular interest was directed towards the extracellular layers of copper-tolerant soft rot fungi....
D M Francis, L E Leightley
Fungal degradation of wood treated with metal-based preservatives. Part 2: Redox states of chromium
1996 - IRG/WP 96-10164
Concerns have arisen about the leaching of heavy metals from wood treated with metal-based preservatives, such as chromated copper arsenate (CCA). Of particular concern is the toxic redox state of chromium and arsenic in aging and decayed CCA-treated wood. Generally, hexavalent chromium is more toxic than trivalent chromium and trivalent arsenic is more toxic than pentavalent arsenic. The desired ...
B Illman, S Bajt, T L Highley
The use of ESR spectroscopy to assess the photostabilising effects of wood preservatives
2000 - IRG/WP 00-20186
The degradation of wood surfaces exposed to UV light which leads to poor performance of clear coatings is understood to be due to delignification via a mechanism involving free radicals. Certain wood preservatives most notably CCA are able to photostabilise wood and therefore they may reduce the concentration of free radicals formed when treated wood is exposed to ultraviolet light. As a first ste...
S Schmid, R D Webster, P D Evans
The chemical analysis and biological evaluation of wood extractives as potential timber preservatives
1995 - IRG/WP 95-30090
Work involved the biological performance of water and organic solvent soluble extractives of four naturally durable wood species, namely; Matumi, Tamboti, Sneezewood and the Turpentine tree. These timber species are known to be naturally durable against termites and fungi (±25 to 35 years). The extractives were evaluated against termites and fungi using impregnated pine pencil stakes in field tes...
P Turner, D Conradie
EELS (Electron Energy Loss Spectroscopy) - a technique for quantification of nitrogen and other light elements in the cell wall
1999 - IRG/WP 99-20163
A literature survey was performed to find progress in techniques for monitoring penetration of synthetic resins in wood cell walls. Electron energy loss spectroscopy (EELS) in combination with transmission electron microscopy (TEM) was successfully applied for the high resolution examination of the distribution of a partly methylated hydroxymethyl melamine resin in Norway spruce (Picea abies Karst...
A O Rapp, H Bestgen, W Adam, R-D Peek
An investigation of organotin compounds in treated wood using Mössbauer spectroscopy
1983 - IRG/WP 3249
The influence of sample preparation on the 119mSn Mössbauer spectrum of tributyltin chloride in ponderosa pine was investigated. Initial studies with sawdust and compressed discs concluded that the latter were clearly superior. Further studies showed that compressed discs prepared from 0.4 g of treated wood and 0.1 g of cellulose were robust and gave excellent Mössbauer spectra. The possibility ...
J N R Ruddick, J K Ingram
UV-microspectrophotometry of lignin and accessory compounds in wood cell walls of conifers
1999 - IRG/WP 99-20171
The distribution of lignin in the cell wall of conifer tracheids was determined by UV-VIS microspectro-photometer. Wood sections of one micron thickness were measured between the wavelength 240 and 700 nm. Spectral analyses revealed that the conifer lignin associated with the tracheid secondary wall and middle lamella is composed of guiacylpropane units which exhibit a characteristic UV absorption...
G Kleist, G Koch, J Bauch
Prediction of Weight Percent Gain (WPG) of furfurylated wood by FT-NIR spectroscopy
2004 - IRG/WP 04-20295
Wood modification based on furfuryl alcohol improves several important wood properties, such as the resistance to fungal decay and insect attack, hardness, dimensional stability, bending strength and stiffness. The improvements of wood properties depend on the weight percent gain (WPG) due to furfurylation. Fourier transform near infrared (FT-NIR) spectroscopy was used to calibrate PLS-regression ...
M Eikenes, P O Flæte, E Ystrøm Haartveit, S Lande
The chemical nature of bis(tributyltin) oxide in Pinus sylvestris sapwood
1989 - IRG/WP 3508
Tributyltin compounds have been used for many years as wood preservatives. This study has provided, for the first time, an explanation for the previously reported dealkylation and/or volatilisation of the tributyltin species in, and from, Scots pine (Pinus sylvestris) sapwood. Thus, 119 Sn nuclear magnetic resonance studies have shown that, on impregnation into this timber, bis(tributyltin) oxide ...
S J Blunden, R Hill
A comparison of inductively coupled plasma spectroscopy and neutron activity analysis for the determination of concentrations in wood
1993 - IRG/WP 93-10048
As wood decays the ionic composition changes, with increases often being seen in the concentrations of Ca, Mg, Fe, Mn and sometimes K. The concentration of eight cations in red spruce sapwood and heartwood samples was determined independently by inductively coupled plasma spectroscopy (ICP) and by neutron activation analysis (NAA) as part of an effort to standardize our analytical procedures and c...
J Jellison, J Connolly, K C Smith, W T Shortle
The compatability of tributyltin fungicides and synthetic pyrethroid insecticides as wood preservatives
1987 - IRG/WP 3414
The stability of three synthetic pyrethroids, cypermethrin, deltamethrin and permethrin, to selected tributyltin compounds, Bu3SnX {where X = OSnBu3, Cl, 02CC6H5, O2C (Naphthenyl), OSO2Et}, (Bu3SnO)3PO and {NBu4} {Bu3SnCl2}, in toluene solution was investigated by infra-red spectroscopy over a six month period. It was found that only (Bu3Sn)2O reacted with the pyrethroids and that their order of r...
S J Blunden, R Hill
Analysis of D-glucose metabolism of wood decay fungi using 13C-NMR and 13C-labeled substrates
2003 - IRG/WP 03-10475
D-Glucose metabolism is thought to be important during wood decay by fungi, not only for anabolic and catabolic purposes of central metabolism, but also as a potential source of peroxide required by extracellular peroxidases. There has been some confusion in the literature as to whether this peroxide-generating activity is of the glucose 1-oxidase or pyranose 2-oxidase (glucose 2-oxidase) type wi...
T H de Koker, M D Mozuch, P J Kersten
NIR spectroscopy for rapid estimation of decay resistance
2004 - IRG/WP 04-20294
In Scandinavia Scots pine (Pinus sylvestris L.) is an important commercial tree species. Its heartwood has traditionally been used in constructions exposed to risk of decay. In a laboratory experiment Scots pine wood specimens sampled from inner heartwood, outer heartwood and sapwood were exposed to the brown rot fungus Poria placenta. In general outer heartwood was more resistant than inner heart...
P O Flæte, E Ystrøm Haartveit
Properties of cellulose degraded by the brown rot fungus, Postia placenta
1988 - IRG/WP 1350
To gain further understanding of the nature of the cellulose depolymerizing agent or agents of brown-rot fungi, brown-rotted cellulose was chemically and physically characterized. Various culture conditions, such as low nitrogen and elevated oxygen levels, did not induce degradation of cellulose by Postia placenta in liquid cultures. Therefore, brown-rotted cellulose for analysis was prepared by a...
T L Highley, R E Ibach, T K Kirk
Solid state NMR study on pine wood degraded by brown rot fungus Gloeophyllum trabeum
1994 - IRG/WP 94-10067
Blocks of Pinus koraiensis wood were degraded by Gloeophyllum trabeum and examined by solid-state 13C NMR spectroscopy. Chemical compositions were estimated from relative signal aras. There was no evidence for preferential degradation of the noncrystalline cellulose which accounted for about 4% by weight of the wood. Loss of partly ordered cellulose on crystal surfaces exceeded the loss of crystal...
Yoon Soo Kim, R Newman