Your search resulted in 124 documents. Displaying 25 entries per page.
Prevention of creosote bleeding from treated Scots pine poles
1970 - IRG/WP III 3B
Creosote, the most widely used preservative for pressure treatment of Electricity Board and GPO transmission poles in the United Kingdom has, when correctly applied, given good performance over a long period of time. Perhaps its only disadvantage as a preservative in the above fields is its tendency to exude or 'bleed' from a proportion of treated poles upon exposure to solar hea...
Anonymous
Protection of southern pine using N,N-Napthaloylhydroxylamine: Field tests, soft-rot cellars and aquatic bioassay leach testing
1999 - IRG/WP 99-30204
Recent environmental restrictions are limiting the use of broad-spectrum biocides for wood preservation. There is an urgent need for new, sharply targeted, environmentally benign wood preservatives. N'N-Napthaloylhydroxylamine (NHA), a water-soluble calcium-precipitating agent, has been shown to inhibit decay by brown-rot and white-rot fungi in soil-block tests and prevent damage by Easte...
D M Crawford, F Green III
Kinetics and mechanism of fixation of Cu-Cr-As wood preservatives. Part 5: Effect of wood species and preservative composition on the leaching during storage
1975 - IRG/WP 354
Conversion reactions during storage of CCA treated wood take place even at and below the fiber saturation point as long as ion transport is possible. Increase in drying temperature increases the final pH of the treated wood and the leachability of Cu and decreases slightly the leachability of Cr, while the leachability of As is not affected. This temperature effect is considered to be of no techni...
S-E Dahlgren
Hemicellulosic induction of oxalic acid in Postia placenta
1994 - IRG/WP 94-10060
Most studies suggest that enzymes produced by brown-rot fungi are too large to penetrate sound wood structures, even after decay begins. Thus, nonenzymatic agents have been proposed to initiate brown-rot decay. We have reported that the brown-rot fungus Postia placenta MAD-698 initiates a 2-fold decrease in wood pH within 7 days of colonization which is mediated by production of oxalic acid. Strai...
F Green III, M Larsen, T L Highley
The long road to understanding brown-rot decay. A view from the ditch
1995 - IRG/WP 95-10101
Interest in understanding how brown-rot fungi decay wood has received increasing interest in recent years because of a need to identify novel targets that can be inhibited for the next generation of antifungal wood preservatives. Brown-rot fungi are unique in that they can degrade holocellulose (cellulose and hemicellulose) in wood without first removing the lignin. Furthermore, they degrade holoc...
F Green III, T L Highley
The effect of water storage on the cell-structure of Sitka spruce (Picea sitchensis) with reference to its permeability and preservation
1970 - IRG/WP III 3A
Commercial treatment trials with full sized transmission poles have shown that water storage considerably improves the permeability of Sitka and Norway spruce. These results were confirmed by laboratory measurements which showed that in the sapwood of ponded Sitka spruce there is a vast improvement in permeability in all three grain directions. Heartwood permeability does not seem to be affected t...
J A Dunleavy, A J McQuire
Targeted inhibition of wood decay (Using everything but the kitchen sink)
1997 - IRG/WP 97-10203
Low molecular weight oxidative decay agents have been implicated in the degradation of wood by brown-rot decay as evidenced by chemical analysis of brown-rotted wood and detection of oxalic acid and hydroxy radicals. Fenton chemistry (H2O2 / Fe++) is often proposed as the mechanism for generating hydroxy radicals. Previous authors have shown iron to enhance the brown-rot hydrolysis of wood, while ...
F Green III, T A Kuster, T L Highley
Kinetics and mechanism of fixation of Cu-Cr-As wood preservatives. Part 6: The length of the primary precipitation period
1975 - IRG/WP 359
The end of the primary precipitation fixation period of CCA preservatives coincides with the first peak in pH versus time. This offers a simple way of estimating the duration of the period. The duration is determined by a number of factors and their interactions, the most important of which are: wood species (anatomy, natural pH, accessibility of reducing agents), preservative type, preservative c...
S-E Dahlgren
Mechanisms of Protection by NHA Against Fungal Decay
2002 - IRG/WP 02-10429
Treating wood with the water-borne sodium salt of N'-N-naphthaloylhydroxylamine (Na-NHA) protects wood against decay and termite damage. Initial testing indicated little or no inhibition of sapstain fungi, molds, or soft-rot fungi by Na-NHA, suggesting that the
mechanism by which this compound protected wood was complex and not that of a broad-spectrum biocide. Previously, we (Green et...
F Green III, W Henry, T Schultz
The fate of salt preservatives in facility yard soils and decontamination of soils and drainage waters
1993 - IRG/WP 93-50001-25
Extensive studies during the past 10 to 15 years revealed that noticeable amounts of preservative components may be released in the environment by dripping off or by rain prior to fixation unless adequate precautions are taken. Therefore, soil and groundwater contamination especially from chromium-VI compounds but also from other inorganic and organic constituents exist in impregnation plants, pos...
R-D Peek, H Klipp, K Brandt
Electrochemical removal of Cu, Cr and As from CCA-treated waste wood
2001 - IRG/WP 01-50166-18
CCA-treated waste wood poses a potential environmental problem due to the content of copper, chromium and arsenic. This paper presents the results obtained by electrodialytic remediation of CCA-treated waste wood. It is found that more than 90% Cu, and approximately 85% Cr and As was removed from the wood during the remediation. Thereby the concentration of copper in the wood is reduced from app. ...
I V Kristensen, L M Ottosen, A B Ribeiro, A Villumsen
Microwave digestion of preserved wood for the determination of Cu, Cr, As, B and P in quality control
1991 - IRG/WP 2364
A microwave digestion method for the determination of copper, chromium, arsenic, boron and phosphorus in preserved woods is described. Samples were digested with nitric acid in pressure-relief type teflon PFA vessels by microwave heating in a commercial laboratory microwave oven. Fast, efficient and complete digestion was achieved within 29 min for 12 samples. The digestion time compared favourabl...
N Bernth, L B Sheard
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
Moderate temperature fixation of CCA-C
1989 - IRG/WP 3522
Several Canadian treating plants are using moderate temperature (40-60C°) fixation chambers to reduce drippage and leaching from fresh CCA treated wood. In this study, chromium reduction and surface leaching properties of CCA-C treated red pine (Pinus resinosa) pole sections were monitored during exposure to temperatures of 50-60C° and 90-100% RH conditions. Chromium-VI concentration in the abso...
P A Cooper, Y T Ung
Fire retardant treated wood and plywood: A comparative study
Part III. Combustion properties of treated wood and plywood
2002 - IRG/WP 02-40236
The fire retardant treated and untreated plywood and alder wood samples were prepared with the aim to investigate the effects of the way of treatment on the combustion properties. Alder wood was used for the preparation of plywood. Boric acid and borax were used as fire retardant. The plywood samples were impregnated by using three different methods; first group samples were impregnated by soaki...
S Çolak, A Temiz, Ü C Yildiz, G Çolakoglu
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
The content and mobility of copper, chromium and arsenic in the soil of a wood preserving plant using CCA
1998 - IRG/WP 98-50122
Analyses were carried out on soil and water samples obtained from a wood preserving plant using CCA-type preservatives. The plant has been in operation since 1969. The soil samples were obtained on 8 points from 4 different depths. The estimation of the type of soil was followed by investigations of copper, chromium and arsenic contents, and the mobility of these elements. The soil samples were al...
N Erdin, S N Kartal, A Dilek Dogu, M O Engür
Detection of increased metal cations after wood decay using Chromeazurol-S
1997 - IRG/WP 97-20112
Chromeazurol-S (CAS) is a dye used for the spectrophotometric determination of metals, mainly aluminum (Al), berillium (Be) and copper (Cu). CAS has been widely used for determining the penetration of copper containing preservatives like CCA (AWPA A3-96). Additional uses include: i) detection of utility pole decay (Esyln, 1979), ii) a chemical spot test for aluminum in wood (Kukachka and Miller, 1...
F Green III, U Srinivasan, R B Miller
Hydrolysis of bordered pits during colonization of conifers by brown-rot fungi
1995 - IRG/WP 95-10103
Brown-rot decay results in rapid reduction in degree of polymerization (DP) of holocellulose with concomitant strength loss (MOR) without removing lignin. Development of new methods of wood protection will require focusing on early events in the sequence of depolymerization. Bordered pit membranes (sapwood) represent a readily available source of non-lignified carbohydrate, ie. pectin and cellulos...
F Green III, J L Tschernitz, T A Kuster, T L Highley
Kinetics of the dissociation of Cr, Cu, and As in fixed CCA-treated wood
2001 - IRG/WP 01-50168
The results of an experiment showing the kinetics of the dissociation of CCA compo-nents in water within treated wood samples are presented. Dry red pine (Pinus resinosa Ait.) samples were simultaneously vacuum-treated with water, then expressed to re-move the water at successive time intervals. The expressate was then analyzed for Cr, Cu, and As concentration by inductively coupled plasma (ICP). ...
L Waldron, P A Cooper
A study of the rate of fixation of various chromium-containing preservatives
1991 - IRG/WP 3653
Denmark, and Scandinavia in general, has perhaps the widest range of approved industrial wood preservative types in the world. As an aid in setting realistic fixation periods, work was undertaken to investigate the rate of fixation of chromium in CCA salt, CCA oxide, CCP, CCB, CC and CCF formulations at summer and winter temperatures. The rate of fixation measured in terms of the concentration of ...
L B Sheard
Accidental mold/termite testing of high density fiberboard (HDF) treated with borates and N’N-naphthaloylhydroxylamine (NHA)
2003 - IRG/WP 03-10462
High density fibreboard (HDF) was made from beech and pine furnish (50:50) and treated with boric acid (0.1-3%), borax (0.1-3%) or N'-N-(1,8-naphthalyl) hydroxylamine (NHA) (0.1-1%) prior to gluing with urea formaldehyde (UF) resin in order to determine resistance to Eastern subterranean termites (Reticulitermes flavipes Kollar), the most economically important termite species in North Am...
S N Kartal, H H Burdsall Jr, F Green III
Immuno-scanning electron microscopic localization of extracellular polysaccharidases within the fibrillar sheath of the brown rot fungus Postia placenta
1991 - IRG/WP 1497
Extracellular polysaccharidases of the brown-rot fungus Postia placenta were localized using colloidal gold labeled monoclonal antibodies to the B-1,4-xylanase (32-36kDa) fraction of Postia placenta. Postia placenta was grown from agar onto glass coverslips, immunolabeled with or without prior fixation, and examined by SEM. Enzymes were localized on the hyphal surface and on the clumped fibrillar ...
F Green III, C A Clausen, M J Larsen, T L Highley
Oral toxicity of a slow-acting insecticide Amdro® to the Formosan subterranean termite
1982 - IRG/WP 1162
The use of toxic baits to control the Formosan subterranean termite Coptotermes formosanus Shiraki requires an insecticide that is non-repellent and sufficiently slow acting that poisoned termites leave treated areas before dying. Of the many insecticides screened, only Amdro® exhibited these characteristics. The oral toxicity (LD 50) of Amdro® to Coptotermes formosanus was estimated at 12.33 µ...
N-Y Su, M Tamashiro, J R Yates III
Distribution of boron from fused borate rods in Douglas-fir transmission poles
1996 - IRG/WP 96-30112
The diffusion of boron from fused borate rods (disodium octaborate tetrachydrate) was monitored over 42 months in CCA-treated Douglas-fir transmission poles. The boric acid equivalent was estimated by the curcumin/salicylic acid color test on increment cores removed from the poles. Moisture content of the poles was quite variable but was always above 20 percent. The percent of increment core lengt...
T L Highley, F Green III, W F Finney