Your search resulted in 195 documents. Displaying 25 entries per page.
The effect of acid rain on CCA treated timber
1990 - IRG/WP 3579
The effect of acid precipitation on the leaching of copper, chromium and arsenic from timber treated with different CCA preservatives was studied in the presence of three types of soil under simulated field conditions. Pine sapwood, embedded in soil, was subjected to simulated rainfall at three different levels of acidity. The CCA preservative formulations tested were:- American Wood Preservers&am...
R J Murphy, D J Dickinson
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
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
An anti-termite formulation for soil treatment with natural products and its efficacy against Coptotermes formosanus Shiraki
2003 - IRG/WP 03-30319
An anti-termite formulation of an environmental conservation type for soil treatment was developed. The formulation was composed of decanoic acid (n-capric acid, an fatty acid derived from coconut oil with ten carbons) as an active ingredient and other natural products. Experiments to examine the efficacy of the formulation against Coptotermes formosanus Shiraki were conducted at the termite field...
S Yoshida, T Nakagaki, A Igarashi, A Enoki
The effect of boric acid on the protozoan numbers of the subterranean termite, Reticulitermes lucifugus
1996 - IRG/WP 96-10148
Lower termites harbor in their guts populations of microorganisms known to be indispensable for their survival, being responsible, at least partially, for the digestion of cellulose, the main item of termites'diet. The Reticulitermes species in particular harbor in their hindguts some unique intestinal fauna, for instance protozoa belonging to the genera Pyrsonympha, Dinenympha and Trycho...
L Nunes, D J Dickinson
Oxalic acid metabolism of Postia placenta
1992 - IRG/WP 92-1566
The oxalic acid metabolism of Postia placenta was studied in liquid culture in order to identify the metabolic pathways of biosynthesis and to determine whether oxalic acid physiology could be correlated with efficiency in wood decay. Oxalic acid production was determined for test strain MAD698 grown in a basal defined medium with a variety of different carbohydrate and nitrogen sources. The highe...
J A Micales
Investigation of copper fixation in timber by sodium nitrit
1992 - IRG/WP 92-3707
Solutions containing mixtures of water soluble copper salts and sodium nitrite have been shown to be capable of producing leach resistant copper treatments when impregnated into timber. A rapid leaching trial showed that copper fixation levels of 85-90% were possible which compared well with the fixation level obtained with conventional hexavelant chromium containing systems in the same test regim...
C Waldie, J A Cornfield
Serpula lacrymans the dry rot fungus. Revue on previous papers
1989 - IRG/WP 1393
It is found that the Dry rot fungus Serpula lacrymans grows in houses only because of its need for basic materials to neutralize the oxalic acid production or heavy metals which celate the oxalic acid. The average distance from the mycelium to the basic materials is found in average to be 14.2 cm with a variation from 0-100 cm. In contrast to Serpula lacrymans the Coniophora puteana and the Rigido...
J Bech-Andersen
Biological resistance of furfuryl alcohol-treated wood
1992 - IRG/WP 92-3703
Biological resistance of FFA (furfuryl alcohol)-treated wood was investigated in relation to the rise of ASE (anti-swelling efficiency) resulting from the treatment. Sapwood blocks of Japanese red pine, cedar and beech were vacuum-impregnated with various concentrations of aqueous FFA solutions to get the target levels of% (w/w) RL (resin loading). Air-dried blocks were kept in an oven at 120°C f...
J Y Ryu, Y Imamura, M Takahashi
Chemically modified tannin and tannin-copper complexes as preservatives for wood
2001 - IRG/WP 01-30271
The efficacy of Mimosa tannin, chemically modified tannin, and tannin-copper complexes as wood preservatives was studied. When the tannin-ammonia-CuCl2 solutions were impregnated into wood specimens in a one-step procedure, a large quantity of the tannin-copper complex was fixed in the specimens. Little of the complex was leached from specimens by a weathering treatment, and these specimens showed...
H Yamaguchi
Oral toxicity of TIM-BOR®, Bora-Careä, boric acid and ethylene glycol against the formosan subterrean termite and easter subterrean termite
1993 - IRG/WP 93-10045
Oral toxicities (LD50) of boric acid, TIM-BOR® (disodium octaborate tetrahydrate: DOT) and BORA-CAREä (40% DOT in ethylene glycol) and ethylene glycol (ca. 80% monoethylene and ca. 20% polyethylene glycol) were estimated. Oral toxicities of BORA-CAREä were significantly higher (LD50: 256.2 µg/g DOT and 304.9 mg/g BAE) than TIM-BOR® alone (LD50: 408.2 µg/g DOT and 485.7 µg/g BAE); indicating...
M Tokoro, N-Y Su
The degradation of wood surfaces by dilute acids
1985 - IRG/WP 3326
Thin radial/longitudinal sections(~100 µ) of Corsican Pine (Pinus nigra) and Lime (Tilia vulgaris), were exposed to Sulphuric, Sulphurous, nitric, acetic, and formic acid at 40°C in the pH range 2-6. After about 3 months exposure to Sulphuric, nitric, acetic and formic acid at pH 2.0 Pine lost some 20-25% of its tensile strength. Losses in tensile strength due to sulphurous acid were greater bei...
P D Evans, W B Banks
The fixation of copper in Pinus sylvestris using the sodium salts of two polyhydroxycarboxylic acids
1992 - IRG/WP 92-3706
As part of the research concerned with the development of fixed, copper based preservatives, the salts of polyhydroxycarboxyIic acids, have been used in copper sequestration studies and fixation trials in Pinus sylvestris splinters. Selected compounds have been shown to be effective sequestrants at low concentrations allowing alkaline solutions to be formulated. Leaching trials following a 48 hour...
M Bacon, J A Cornfield
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
Detrimental effects of boric acid on symbiotic protozoa in Reticulitermes flavipes (Kollar) and Coptotermes formosanus Shiraki (Isoptera: Rhinotermitidae)
2000 - IRG/WP 00-10366
In laboratory choice bioassays, Reticulitermes flavipes (Kollar) and Coptotermes formosanus Shiraki were offered a tunneling soil consisting of boric acid (BA) mixed with sterilized soil at concentrations of 0.05, 0.25, 0.50, 1.00, 2.00, or 4.00 percent AI (wt:wt). Termites could choose to remain in their main nest that contained non-treated artificial substrate and adequate food, or tunnel throug...
B M Kard
Anti-sapstain chemicals for diffusion treatment of rubber wood
1986 - IRG/WP 3367
Performance of Sinesto B and Akzo EN 494, two formulated products of alkyl ammonium compounds, was tested as fungicidal additive in the boron solution to control mould and stain during diffusion storage of rubber wood. Sinesto B at 2.0% (a.i.) concentration has given good control over mould and its protection against sapstain was only satisfactory. Akzo EN 494 at 0.7% (a.i.) concentration has give...
R Gnanaharan
Removing Cu, Cr and As from CCA treated yellow pine by oleic acid
2003 - IRG/WP 03-50202
In this study, CCA treated yellow pine utility poles were cut into three different dimensions and 4 different pH levels (2, 2.5, 3.5 and 5) of Oleic acid was used. The leached wood samples were collected at the end of the 1, 3, 7 and 14 days to determine the remaining Cu, Cr and As concentrations. The concentrations of Cu, Cr and As were determined by X-RF. The effects of pH, dimension and duratio...
E D Gezer, Ü C Yildiz, S Yildiz, E Dizman, A Temiz
CCA removal from treated wood by chemical, mechanical and microbial processing
1998 - IRG/WP 98-50101-26
Most preservative-treated wood produced and consumed in the U.S. is treated with toxic inorganic compounds containing copper, chromium, and arsenic. Because chromated copper arsenate (CCA) is fixed to the wood, treated wood has not been considered toxic or hazardous and is currently landfilled. Increasing public concern about environmental contamination from treated wood combined with increasing q...
C A Clausen, R L Smith
The efficacy of boron preparations
1987 - IRG/WP 3400
The toxicity threshold of boric acid for egg larvae of Hylotrupes bajulus Linné is approx. 0.4 kg/m³ of wood (71 g B/m³) over a 12-week test period, and approx. 0.3 kg/m³ of wood (53 g B/m³) over a 6-month test period. The corresponding values for borax are 0.5-0.6 kg/m³ of wood (56-68 g B/m³) and 0.3-0.4 kg/m³ of wood (34-45 g B/m³). The values are somewhat lower in the case of the egg l...
J T De Jonge
Redistribution of boric acid in radiata pine during drying after preservative treatment
1993 - IRG/WP 93-40010
Samples of 100 x 50 mm² radiata pine were processed with a variety of options to produce dry, boron-treated wood. Concentrations of boric acid in the central one-ninth and in the whole of the wood cross-sections were determined by chemical analysis and compared. Diffusion treated material was dried by air, conventional kiln (70/60°C), or high temperature kiln (120/70°C). Four different predryin...
A J Bergervoet, D R Page, J A Drysdale
A comparison of fatty acid and molecular profiles for identification of wood colonizing basidiomycota
2003 - IRG/WP 03-20278
Two methods that are currently being employed to detect and identify wood decay fungi are Fatty Acid Methyl Ester (FAME) analysis and Restriction Fragment Length Polymorphism (RFLP) analysis. A FAME library and RFLP library for 9 species and up to 10 strains within each species have been developed. The profiles generated by these methods have been compared for each species and strain to test for...
T C McElroy, L Prewitt, S V Diehl
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
Effects of the sulfuric acid modification of CCA treating solution
1987 - IRG/WP 3415
Sulfuric acid modification of CCA treating solution is often used to control the formation of sludges and undesirable deposits on the surface of treated wood. The consequences of sulfuric acid addition are examined in this work and negative effects are shown to far outweigh any benefits. Major risks include the loss of copper due to leaching from treated wood and the accelerated corrosion of treat...
R F Fox, H J Fry, E A Pasek, A S Ross
A combined method for drying and preserving wood in a single step process
2000 - IRG/WP 00-40183
Based on a convective dryer, this process allows to dry and treat wood blocks with diffusible preservatives in the same time. A boric acid solution (heated to fix the wet temperature of the system) is pumped and introduced in the flow system through a venturi, where the air coming back from the drying cell also arrives. The role of the venturi is to create a dispersion of boric acid solution micro...
O Colin, C Dupuis, E Mougel, A Zoulalian, M-F Thévenon
Effects of hard water, sea water and humic acid on the release of CCA components from treated wood
2005 - IRG/WP 05-50228
Leaching medium is an important factor affecting release of preservative components from treated wood because physical and chemical characteristics of medium increase or decrease the solubility of fixed preservative components. This study evaluated the leaching properties of copper, chromium and arsenic elements from chromated copper arsenate (CCA)-treated wood specimens subjected to laboratory le...
S N Kartal, W J Hwang, Y Imamura