Your search resulted in 54 documents. Displaying 25 entries per page.
The use of a physical field model to study the effects of remedially treated timber on the growth of perennial ryegrass (Lolium perenne) and rye (Secale cereale), and the accumulation of toxic preservative constituents in Lolium perenne
1995 - IRG/WP 95-50040-02
Low cost laboratory model systems can be used to give relatively rapid indications of the environmental effects of preservative treated timber in soil contact. This paper details the effects of remedially treated timber on the growth of crops of Lolium perenne and Secale cereale seeded on soilbeds of different texture in close proximity to remedially treated creosoted pole sections. Lolium perenne...
D C R Sinclair, G M Smith, A Bruce, H J Staines
Assessment of dehydrogenase activity, fluoride content and total chromium content of soil profiles exposed to preservative treated wood within a model system
1993 - IRG/WP 93-10015
The development and prospective use of a closed model system to facilitate study of a number of indicators of environmental impact of wood preservatives laboratory conditions has been described (IRG/WP/2395-92). Chemical analysis of leachate samples collected from drained soil profiles containing creosoted pole sections remedially treated with a chromated fluoride preservative indicated small incr...
G M Smith, D C R Sinclair, A Bruce, H J Staines
Initial results and observations of a model system to assess the efficacy and environmetal impact of preservative treated wood
1993 - IRG/WP 93-50001-02
The development of a closed model system for the laboratory assessment of the efficacy and environmental impact of a chromated fluoride remedial treatment for creosoted distribution poles has been described (IRG/WP/2395-92). The model consists of a precipitation apparatus above a treated pole section positioned in a soil profile from which leachate was collected via a series of simulated field dra...
D C R Sinclair, G M Smith, A Bruce, H J Staines
Reaction of osmium tetroxide with a diphenolic compound as a model substance for demethylated lignin
1986 - IRG/WP 1303
By using caffeic acid as a model substance for diphenolic moieties of demethylated lignin it was found that electron dense particles called by the authors "osmiophilic particles" in former papers are reaction products of OsO4 with the model substance. By these products it is possible to indicate the enzymatic demethylation of lignin taking place during wood decay. The appearance of the electron de...
K Messner, E Srebotnik
Proposed model for the penetration and decay of wood by the hyphal sheath of the brown-rot fungus Postia placenta
1989 - IRG/WP 1391
Scanning electron microscopy (SEM) of Pinus sp. decayed by the brown-rot fungus Postia placenta confirmed the existence of extracellular membranous structures previously described by transmission electron microscopy (TEM). These structures appear to be an integral part of the hyphal sheath and assume a variety of forms including lamellar sheets, fibrils, and vesicles. These structures were observe...
F Green III, M J Larsen, L L Murmanis, T L Highley
Degradation of lignin model compounds with coordinated copper in the presence of peroxide
1998 - IRG/WP 98-10282
A novel diffusible system capable of decomposing lignin model compounds with copper, coordinators and peroxides has been proposed. When pyridine was used as a copper coordinator, two synthetic dyes, Poly-R and RBBR were intensively decolorized with Cu(II) and H2O2 in aqueous solutions at room temperature. Although reactions with Cu(II) and H2O2 produce a strong oxidant, hydroxyl radical, via a Fen...
K Koller, K Messner, T Watanabe
The impact of global warming on the UK distribution of house longhorn beetle Hylotrupes bajulus (L)
2001 - IRG/WP 01-10414
This paper reviews the effects of global warming on insect populations and distribution. The affects of global warming on the spread of Hylotrupes is predicted through a review of research related to the influence of temperature on its life-cycle and flight. Records of Hylotrupes distribution were obtained from published surveys, entomologists and museum collections and were plotted for the UK. Th...
P Oevering, A J Pitman
Dimensional lumber model demonstrates the sensitivity of the particle capture immunoassay in early detection of brown-rot fungi
1995 - IRG/WP 95-20058
A dimensional lumber model was designed to test the sensitivity of the particle capture immunoassay (PCI) compared to traditional methods of culturing and microscopic examination for detection of brown-rot fungi. Southern yellow pine 2 x 4's (5.1x10.2 cm²), and 86.4 cm in length, were inoculated on one end with the brown-rot fungus, Postia placenta, and tested over the full length of the...
C A Clausen, L Ferge
Development of a model system to assess the efficacy and environmental impact of a chromated fluoride remedial treatment for creosoted distribution poles
1992 - IRG/WP 92-2395
A closed model system was designed to facilitate a controlled study of the leachability and environmental fate of a remedial preservative under laboratory conditions. The elements of the model include a precipitation apparatus above a treated pole section which is positioned in a representative soil profile supporting a sward of perennial ryegrass. The model will allow detailed examination of the ...
D C R Sinclair, G M Smith, A Bruce, B King
Mechanistic aspects of the reactions of copper complexes with lignin in the presence of hydrogen peroxide and lipid hydroperoxide model compounds as proposed for white rot fungi
2001 - IRG/WP 01-10399
The structural principles and the oxidative reactions of the catalytic system consisting of copper, hydroperoxides, and copper coordination compounds that contain aromatic nitrogen atoms are similar to those of catalytic centers of oxidative enzymes involved in delignification reactions of white rot fungi. The system is capable of selectively degrading lignin and its low molecular weight would all...
K Fackler, P Lamaipis, E Srebotnik, M Humar, C Tavzes, F Pohleven, M Sentjurc, T Watanabe, K Messner
Comparison of Temporal Changes in Metal Leaching and Aquatic Toxicity from Wood Treated with CCA and Alternative Preservatives
2005 - IRG/WP 05-50236
This study compares the temporal variation of chemical leaching and aquatic toxicity of wood treated with chromated copper arsenate (CCA) and other copper-based wood preservatives (alkaline copper quaternary (ACQ), copper boron azole (CBA), copper citrate (CC) and copper dimethyldithiocarbamate (CDDC)). Treated wood blocks were leached for 21 days and the leachate collected was analyzed for prese...
B Dubey, T G Townsend, G Bitton, H M Solo-Gabriele
A diffusion and reaction model for the leaching of Cr-VI from unfixed CCA-treated wood
2001 - IRG/WP 01-50169
A physical model applicable to the leaching of any substance undergoing a first-order fixation reaction with wood is presented. Using this model and a laboratory leaching experiment with small wood samples immersed in water, the radial and tangential diffusion coefficients and the reaction rate constants of Cr-VI in unfixed CCA-treated red pine (Pinus resinosa Ait.) are measured. Reaction rate con...
L Waldron, P A Cooper
A model for attack at a distance from the hyphae based on studies with the brown rot Coniophora puteana
1995 - IRG/WP 95-10104
In timber infested by brown rot fungi, a rapid loss in strength is attributed to production of hydroxyl radicals (HO·) at a distance from the hyphae. The immediate precursor is Fenton's reagent (Fe(II)/H2O2), but the pathways leading to Fe(II) and H2O2 have remained unclear. Cellobiose dehydrogenase, purified from cultures of Coniophora puteana, will couple oxidation of cellodextrins to ...
S M Hyde, P M Wood
Fire Safety of Wood Floor Assembly: Model and Full-scale Test
2007 - IRG/WP 07-20375
The present paper describes the model for the prediction of fire safety of wood floor assemblies. The model includes heat transfer model for the calculation of the flow of heat in floor assembly and structural model for the analysis of the mechanical performance of wood joists. The floor assemblies considered in this paper are constructed with nominal 2x10 (38x241mm) wood joists lined by Type X ...
H Takeda
Estimating the age of subterranean termite attack and damage in buildings
2010 - IRG/WP 10-10727
This paper describes physical and experimental methods and a mathematical model (Rotramel 2003) to assist in estimating the age of subterranean termite attack and damage to building structures. Timber, building and termite management industries have to develop new strategies to assess and estimate termite attack and damage in the current climate of global warming. A case study will be used as an e...
J R J French, B M Ahmed Shiday, J Thorpe
Finite Element Modelling of the Checking of Wood Exposed to Accelerated Weathering
2010 - IRG/WP 10-20459
The surface checking that develops when wood is exposed to the weather reduces the visual appeal of treated wood products and can reduce the effectiveness of preservative treatments. There is strong interest in developing solutions to this problem and also a growing realization that such solutions may evolve from a deeper understanding of the mechanisms responsible for surface checking. In this pa...
S G Ribarits, P D Evans
Assessment of Boracol 200RH (FrameSaver) as a remedial treatment to control decay in pre-decayed model timber frame units
2010 - IRG/WP 10-30529
Model timber frame units constructed from untreated radiata pine were pre-wetted to approximately 40% moisture content and inoculated with Coniophora puteana and Oligoporus placenta. Units were transferred to a controlled environment room maintained at 25°C and 95% RH for 7 and 10 weeks to allow two levels of decay to become established in units. Following pre-decay, units were disassembled, clea...
Mick Hedley, Dave Page, Jackie van der Waals
Kinetic Water Vapour Sorption of Sitka Spruce at Variable Temperature Using the Parallel Exponential Kinetics Model
2010 - IRG/WP 10-40512
In this study the water vapour sorption of Sitka spruce (Picea sitchensis (Bongard) Carr.) was measured using a Dynamic Vapour Sorption (DVS) apparatus and then analysed using the parallel exponential kinetics (PEK) model. The water vapour sorption rate of wood quickly increased when the relative humidity was changed. With the elapse of time, the sorption rate gradually decreased within any specif...
Yanjun Xie, C Hill
A survey of factors affecting decay resistance of wood modified with acetic anhydride
2012 - IRG/WP 12-40594
From the range of information published, acetylation appears well suited to provide adequate protection against biological attack for materials derived from typically non-durable wood species. Acetylated wood is now commercially available both in Europe and in the USA. But still there are a lot of unanswered questions related to fungal decay mechanisms in acetylated wood. The paper summarize exist...
G Alfredsen, P O Flæte, H Militz
Application of a model for the prediction of fungal degradation of thermally modified beech timber by Trametes versicolor
2013 - IRG/WP 13-40622
Colour measurement technology is found to be feasible for characterization of the property changes of thermally modified timber (TMT). In opposite to time-consuming and expensive laboratory tests a non-destructive test represents an improvement for the manufacturer of TMT. Therefore the aim of this study was to develop a method which allows sorting the different treatment intensities after the man...
Clauder, L., Richter S., Unger, W., Pfriem, A
Modelling the risk for mould growth on timber stored outdoors protected from rain
2013 - IRG/WP 13-20529
A mould resistance design (MRD) model was used to calculate the maximum duration of storage of timber outdoors under cover (protected from rain) before the onset of mould growth on the surface of wood. The prediction model is based on laboratory tests performed in constant and cyclic climates and were also confirmed against exposure tests in attics and crawl spaces. The prediction model presented ...
E Frühwald Hansson, S Bardage, S Thelandersson
Interaction between Aspergillus niger fungus and other filamentous fungi on salt-agar medium and their growth on natural wood and wood treated with fungicide
2015 - IRG/WP 15-20569
Aspergillus niger (An) is very often used alone or in mixture with other filamentous fungi of the genus in testing biocides in disinfection procedures, safety, hygiene, medical fields as well as for testing resistance of wood and wood-based materials to moulds. Softwood species as well as hardwood are overgrown with An fungus very easily, causing drop of mainly the aesthetic value of wood product....
A Fojutowski, A Kropacz, A Koziróg
Foundation piles: analysis of beech wood decay in service life conditions
2016 - IRG/WP 16-10858
Wood piles foundation system was largely used over decades. Thus, numerous buildings over the world are based on this constructive system. In the context of reduction of CO2 emissions in the building field of constructions, substitution of concrete by wood as material for foundation piles seems to be a promising alternative. However, fluctuation of the water table level in soil may promote fungal ...
Q Kleindienst, A Besserer, M-L Antoine, C Perrin, J-F Bocquet, L Bléron
Development of decay hazard maps based on decay prediction models
2016 - IRG/WP 16-20588
Durability plays a very central role in timber engineering, especially when working with wood in use class 3 and above where the risk of decay is high. As one of the primary decay influencing factors, the external condition, i.e. the local climate, is often graded by some type of climate index value. Predominately, climate indices are based on a direct relationship between weather data and decay. ...
J Niklewski, E Frühwald Hansson, C Brischke, D Kavurmaci
Modelling of moisture content in timber bridge details
2017 - IRG/WP 17-20613
The design of details is an important aspect in durability design of timber bridges. Details are often considered the weakest points in bridges due to their tendency to trap and accumulate moisture and thus facilitate decay. When designing maintenance plans and inspection intervals, it is important to know how design choices will come to influence the service life. Moreover, service life and wood ...
J Niklewski, C Brischke, E Frühwald Hansson, L Meyer-Veltrup