Your search resulted in 69 documents. Displaying 25 entries per page.
Characterisations of the mode of action(s) of Methylene bisthiocyanate (MBT) in Ophiostoma floccosum
2005 - IRG/WP 05-10554
Potassium (K+) leakage, oxygen consumption, glucose depletion and level of ATP formation were determined to elucidate the potential target site(s) of MBT on the sapstain fungus O. floccosum. Treatment of O. floccosum with MBT caused an efflux of intracellular K+ ions from the cells, and the rate of leakage increased with increasing MBT concentrations up to a certain value. This observation sugge...
T Singh, B Kreber, A Stewart, M Jaspers
Effect of some resin treatments on fungal degradation reactions
1999 - IRG/WP 99-10318
The effect of impregnation of wood with vegetable oil, tall oil and two water soluble on fungal degradation reactions was assessed by hydrolysis and enzyme activity measurements. The experiments were carried out by using isolated enzyme preparations and a living brown-rot fungus Poria placenta. The results indicate that the inhibitory effect of treatments was clearly directec towards the enzymatic...
A-C Ritschkoff, M Rättö, A J Nurmi, H Kokko, A O Rapp, H Militz
Chitosan for wood protection - state of the art
2005 - IRG/WP 05-30378
The aim of this paper was to give a state of the art description of chitosan as a wood protecting agent. Chitosan is a metal free natural compound derived from crustacean shells and is under evaluation as an environmentally benign wood protecting agent. Information from journals states that chitosan may act both fungistatically and at higher concentrations, as fungitoxic, but the mode of action is...
M Eikenes, G Alfredsen, E Larnøy, H Militz, B Kreber, C Chittenden
Breakdown of cellulose derivatives by cellulolytic enzymes. I. Action of fungal ß-glucosidases toward substituted PNP ß-D-glucopyranosides
1998 - IRG/WP 98-10281
The action of fungal ß-glucosidases on the methyl derivatives of p-nitrophenyl (PNP) ß-D-glucopyranoside, which were regioselectively substituted at 0-2, 0-3, 0-4 and 0-6 positions was studied. Several ß-glucosidases from brown-rot, white-rot, and soft-rot fungi and almond were used for the study. These ß-glucosidases did not act on the 2, 3, and 4-0-methyl derivatives, while the 6-0-methyl on...
T Nishimura, I Momohara, M Ishihara
Targeted inhibition of wood decay fungi: degradation of cotton cellulose
1999 - IRG/WP 99-10321
Brown-rot decay is responsible for 80% of the damage and replacement of wood in service. For nearly thirty years, researchers have postulated a one-electron oxidase system combining Fe+2 oxalic acid, and H2O2 in the production of hydroxy radicals which ultimately oxidize cellulose in situ. Recently, researchers have been investigating antioxicants, in combination with biocides (Schultz, et al.,199...
F Green III, T A Kuster
Studies of the mechanism of chromated-copper preservative. Fixation using electron spin resonance
1992 - IRG/WP 92-3701
Two softwoods and one hardwood species were treated with chromium trioxide, copper sulphate, chromated-copper wood preservative (CCA). The treated wood samples were analyzed during fixation by electron spin resonance (ESR). ESR spectra indicated that more than one Cr(V) species was generated from Cr(VI) soon after CCA treatment. The Cr(V) signal became strong within increased several hours followe...
K Yamamoto, J N R Ruddick
The lasting dehydration of wood treated by bifluorides worked up in Diffusec noticed by a continual drying of the wood
1999 - IRG/WP 99-30196
After an immersion of sound wood in a solution of Diffusec, in which a combination of acid potassium and ammonium bifluorides = FHF- in dissociated form is present, their potassium and ammonium fluoride ions together with the bifluoride ion = (FHF-) diffuse into the wood. They make use of the woodmoisture available as O-H-O bonds directly attached to the cellulose in the wood fibres to attract the...
H F M Nijman
Environmentally benign wood preservatives based on organic biocide antioxidant combinations: A brief review of laboratory and field exposure results and discussion of a proposed mechanism
2004 - IRG/WP 04-30335
The combination of various organic biocides with commercial antioxidants generally increased the biocides’ efficacy 2-3 fold against wood-destroying fungi in short-term laboratory decay tests, and some positive results have been obtained after 2-4 years of outdoor exposure. The two antioxidants principally examined, propyl gallate and butylated hydroxytoluene, are low cost and, since both are f...
T Schultz, D D Nicholas, W Henry, C Pittman, D Wipf, B Goodell
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
Evaluation of tropolone as a wood preservative : activity and mode of action
2002 - IRG/WP 02-30282
The fungicidal activity of 2-hydroxy cyclohepta-2,4,6-trienone (tropolone) analogue of b-thujaplicin a natural product responsible for the durability of heart wood of several
cupressaceous trees was investigated in vitro on growth of white and brown rot fungi. Results obtained show that tropolone, easily prepared from commercially available products,
possesses strong fungicidal activity similar ...
P Gérardin, M Baya, N Delbarre, P N Diouf, D Perrin, P Soulounganga, E Gelhaye,
J P Jacquot, C Rapin
Insect growth regulators: modes of action and mode of action-dependent peculiarities in the evaluation of the efficacy for their use in wood preservation
1997 - IRG/WP 97-30155
Up to now, the insecticides used in wood preservation are either of more or less non-specific mode of action - like boron - or of neurotoxic mode of action - like chlorinated hydrocarbons, carbamates and pyrethroids. The active ingredients actually used are primarily mirroring the progress in active ingredient research in plant protection. The methods of testing of the insecticidal efficacy of woo...
M Pallaske
The action of siderophores isolated from Gloeophyllum trabeum on the structure and crystallinity of cellulose compounds
1991 - IRG/WP 1479
Low molecular weight, high affinity iron-binding compounds (siderophores) were isolated from the brown-rot fungus Gloeophyllum trabeum. The compounds were shown to be inducible by iron starvation and could be purified by ultra-filtration, ethyl acetate extraction, column chromatography and preparative HPLC. The isolated compounds were shown by analytical and immunological techniques to be produced...
J Jellison, V Chandhoke, B Goodell, F Fekete, N Hayashi, M Ishihara, K Yamamoto
COST Action E31: Management of Recovered Wood
2005 - IRG/WP 05-50224-26
The COST (European Co-operation in the Field of Scientific and Technical Research) Action E31 (2002 to 2006) is a multi-disciplinary forum for the exchange of information on “Management of Recovered Wood” with the main objective to improve the European management of recovered wood towards a higher common technical, economic and environmental standard. Researchers of 20 European countries – A...
G Jungmeier, B Hillring, A Frühwald, M Humar
Kinetics and mechanism of fixation of Cu-Cr-As wood preservatives. Part 4: Conversion reactions during storage
1974 - IRG/WP 332
Precipitates simulating those produced in wood by preservative fixation reactions were prepared by the reduction of Boliden K 33 and Celcure AP solutions with hydrogen peroxide and hydrazine. The pH changes on aging at 20 and 50°C were studied and related to the chemistry of fixation previously described. Hydrolysis of copper arsenates may render arsenic acid temporarily water soluble pending pre...
S-E Dahlgren
Social and economocal impact of an extension of service life resulting of an adequate preventive treatment. Application to wooden components used in urban areas with a high density of population
1993 - IRG/WP 93-50001-15
Le document évalue les problèmes rencontrés en zone urbaine pour le sauvetage des constructions: coordination de la lutte, délimination des chantieres et des périmètres d'investigation, nuisances causées par les interventions, risques pour la santé, risques pour l'environnement. Coûts. Comparaison socio-économique du traitement préventif et des interventions à posteri...
A T De Lelis, G A C Lopez
The bacterial transformation of organic biocides; a common mechanism?
2006 - IRG/WP 06-10585
It was found that a number of unformulated organic biocides showed a susceptibility to degradation by proteobacteria. Exposure of tebuconazole, a candidate biocide, chlorothalonil and IPBC to a Ralstonia strain was found to result in biocide detoxification, as demonstrated through HPLC and a bioassay. Exposure of the biocides to a previously identified extracellular factor was also found to resu...
D F Wallace, D J Dickinson
The effect of chitosan on the growth and physiology of two wood inhabiting fungi
2006 - IRG/WP 06-10590
The effect of chitosan on the wood inhabiting fungi Sphaeropsis sapinea and Trichoderma harzianum was evaluated at cellular level. Increasing concentrations of chitosan caused an increase in the amount of peroxide in cultures of S. sapinea, which was accompanied by a simultaneous decrease in superoxide. The same effect was not observed in T. harzianum. The growth of both fungi was inhibited when h...
D Vesentini, T Singh
The Effect of Wick Action upon Moisture Distribution in Ellagate Treated Pinus radiata Wood
2006 - IRG/WP 06-40328
Sapwood stakes of Pinus radiata D. Don were treated with water-soluble tetraguanidinium, tetracholine and tetrakis-benzyltrimethylammonium ellagates. The effect of these treatments upon moisture distribution was investigated by wick action. Given that chemical reactions within the wood substrate between nutrients and treatment solutions may alter the properties of the wood with regard to moistur...
S R Przewloka, B J Shearer, J A Hann
Arsenic removal by plant pumping mechanism from arsenic solution using activated aluminum oxide as adsorbent – a preliminary study
2006 - IRG/WP 06-50239
This study evaluated the performance of plant pumping mechanism for removal of arsenic from arsenic solution using activated aluminum oxide as adsorbent. Generally, plants absorb water from soil mainly by osmosis process and toxic elements present in soil also move along with water. To remove toxic elements present in contaminated soils/water, different chemical substances are widely used as
...
B Tarakanadha, H Koyanaka, T Hata, Y Imamura
The characteristics of biodegradation mechanism of gamma-irradiated wood
2007 - IRG/WP 07-20352
Gamma radiation, as an easy, fast and effective sterilisation method, changes molecular structure in pest’s living cells, but also in wooden cell walls. Radiation-induced depolymerisation causes significant changes in wood properties crucial for laboratory testing of wood-preservative effectiveness. Natural durability of wood against rot fungi in lab conditions dependency on different sterilisat...
R Despot, M Hasan, F Pohleven, M Humar, G Rep
Effect of chitosan on the morphology and ultrastructure of two wood inhabiting fungi
2007 - IRG/WP 07-10606
An investigation was undertaken to compare the antifungal effects caused by chitosan against two selected wood degrading fungi Sphaeropsis sapinea and Trichoderma harzianum on their growth, morphological and ultra-structural characteristics, using differential interference microscopy, epifluorescence microscopy and transmission electron microscopy.
The effect of chitosan on fungal morphology was ...
T Singh, A P Singh, G Daniel
Field Stake Tests with Copper-based Preservatives
2008 - IRG/WP 08-30459
The performance of field test stakes derived from commercially produced ground contact retention
copper quat preservatives based on either soluble copper complexed with ethanolamine, or from a water-based suspension of particulate micronized copper compounds, as well as untreated southern yellow pine controls, is compared at two decay test sites. After less than one year in field test some of t...
A Preston, L Jin, D Nicholas, A Zahora, P Walcheski, K Archer, T Schultz
COST Action E37. Sustainability Through New Technologies For Enhanced Wood Durability -
2008 - IRG/WP 08-40417
The main overall objective of the Action was to concentrate on the contribution of wood durability to sustainability through the development of systems for quality assurance and performance classification of modified wood and wood products as alternatives to wood treated with traditional preservatives. By this means it seeked to improve and consequently to increase the cost-effective use of compon...
R-D Peek, J Van Acker
A Comprehensive Review of Copper as a Biocide, with a Focus on Micronized Copper
2008 - IRG/WP 08-30486
This paper reviews the wood preservative biocide active ingredient copper and delvers into new and previously unpublished data regarding the new micronized formulations which are now in vogue and widespread use in N. America in all residential treated lumber markets. Included in this review is the overall discussion of copper containing formulations used for pressure treated wood used over the las...
M H Freeman, C R McIntyre
Antinomic natural self-protection mechanism in long-lasting woods: a case study with three tropical species from French Guiana
2009 - IRG/WP 09-10696
We demonstrate in this work through 3 examples that Amazonian trees may specialize long-lasting woods by means of at least to different approaches. Wallaba impregnates its wood with large amounts of weakly antifungal compounds acting in synergy, while tatajuba and louro vermelho woods are naturally impregnated with antifungal agents. Comparison of biological activities in vitro and concentrations ...
A Rodrigues, M Royer, N Amusant, J Beauchêne, G Herbette, V Eparvier, A Thibaut, L Salmen Espíndola, B Thibaut, D Stien