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The effect of steam conditioning on Southern yellow pine treated with copper naphthenate
1997 - IRG/WP 97-40086
The current study was undertaken to investigate the influence of steam conditioning on Southern yellow pine treated with copper naphthenate (Cu-N). Pre-steamed and /or kiln-dried Southern yellow pine were pressure treated with Cu-N. After treatment, one group of samples were post-steamed. It was found that samples changed color from green to dark-brown after post-steaming. To elucidate the effect of steaming on treated wood, several techniques, namely, environmental scanning electron microscopy equipped with energy dispersive X-rays analysis (ESEM-EDXA), X-ray diffractometry (XRD), and X-ray photoelectron spectroscopy (XPS) were employed. After post-steaming, ESEM showed clearly crystal deposit on the Cu-N treated samples, and EDXA data suggested that the crystal was copper and oxygen contained compound identified as Cuprous Oxide (Cu2O) by XRD. The amount of Cu2O in wood samples was semi-quantitatively determined with XRD. XPS C1s spectra showed that post-steaming decreased C1 contribution and increased O/C ratio attributed to the loss of oil rich in hydrocarbons. The removal of water solubles extractives rich in carbon explains the decrease of O/C ratio. The resistance of copper to water leaching was improved by pre-steaming contrary to the post steaming which resulted in high copper loss.
Jun Zhang, D P Kamdem, M H Freeman, R D Arsenault


Ultrastructural and TEM-EDAX studies on the degradation of CCA treated radiata pine by tunnelling bacteria
1985 - IRG/WP 1260
An ultrastructural study was carried out on bacterial attacked Pinus radiata stakes treated with a high level (24.7 kg/m³) of Tanalith NCA preservative. The purpose of the investigation was to determine whether the organism possessed intracellular and/or extracellular detoxification mechanisms in order to overcome the high levels of copper, chrome and arsenic present within the wood fibre walls. Correlated T.E.M. and T.E.M.-EDAX studies showed most of the preservative elements to remain outside the bacteria associated with bacterial tunnel wall and cross-wall extracellular secretions. T.E.M.-EDAX showed the levels of preservative elements present in the tunnel walls and cross walls to often greatly exceel that recorded in neighbouring S2 cell wall regions, while studies on the bacteria showed that only copper and very low levels of chromium and arsenic had entered the cells. Observations suggested that the metals found within the cells were associated with electron-dense deposits or inclusions within the nuclear region or cell cytoplasm, the deposits often containing high levels of phosphorus and calcium together with lesser levels of other cations. The study also provided evidence for the direct visualisation of CCA preservative elements within fibre walls using T.E.M. without any form of secondary chemical enhancing, and in addition, considerable new information on the nature and structure of the single celled, Gram-negative, motile bacteria involved in the decay.
G F Daniel, T Nilsson


Chemical investigation of 23-year-old CDDC treated southern yellow pine
1997 - IRG/WP 97-30141
The effect of 23 years exterior exposure on CDDC treated southern yellow pine was evaluated by the application of solid state analytical instrumentation. Analytical methods including environmental scanning electron microscopy (ESEM),energy dispersive X-ray analysis (EDXA), X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), inductively coupled plasma (ICP) and atomic absorption spectroscopy (AAS) were used to study CDDC treated wood. The results of this study support modification of CDDC in treated wood with time. Data from ICP and AAS analysis indicated that about 60% of copper and 81% of SDDC are removed from the 1/8"shell of the below ground portion of the stakes after 23 year field exposure. The molar ratio of SDDC to copper for freshly treated southern yellow pine is 2 while it is reduced to 1 after 23 years field exposure. ESEM micrographs and EDXA data confirm the presence of solids rich in copper and sulfur similar to that of CDDC in freshly treated samples. XRD patterns suggest some modifications in the CDDC solids remaining in wood after 23 years.
D P Kamdem, C R McIntyre


An interim report on studies of the tolerance by Sphaeroma (Crustacea: Isopoda) of CCA-treated timber
1982 - IRG/WP 491
In Papua New Guinea any untreated timber exposed to seawater close to mangrove stands is liable to be attacked in the intertidal zone by the crustaceans Sphaeroma terebrans or Sphaeroma triste. Even CCA-treated timber is sometimes vulnerable. The mouth-parts of these animals are adapted for boring, but whether wood particles are ingested remains to be resolved. Some limbs of Sphaeroma terebrans appear to be adapted for filter-feeding. In both species a portion of the gut, the hepatopancreatic caeca, contains cells in which large quantities of copper are concentrated. Specimens of Sphaeroma terebrans taken from CCA-treated piles had an average of 35 mg copper per gram dry weight of hepatopancreatic caeca: the corresponding figure for Sphaeroma triste was approximately 7 mg/g. Specimens of Sphaeroma terebrans taken from mangroves had much less copper in them than those from treated wood. No such clear-cut difference was evident in the case of Sphaeroma triste. Analyses of CCA-treated piles infested with Sphaeroma showed that Cu, Cr and As levels were high at the surface, but that levels in the interior of the pile had dropped since installation Further studies of Sphaeroma gut function are in progress.
S M Cragg, J D Icely


The interaction of polyflavonoid tannins with CCA in Pinus radiata
1987 - IRG/WP 3422
Polyflavonoid tannins complex easily and rapidly with metal ions such as copper, chromium, and arsenic. such complexes in high-tannin-containing CCA treated hardwoods might result in essentially under-treated timber. Four aspects of this interaction were investigated: 1) The relationship between tannin contents of seven hardwoods (Betula pendula, Alstonia scholaris, Fagus sylvatica, Liquidambar styraciflua, Nothofagus menziesii, Platanus acerifolia and Tilia vulgaris) and one softwood (Pinus radiata) and% Cu toxic thresholds; 2) Determination of tannin distribution within cell wall layers; 3) The field performance of Pinus radiata treated with solutions of bark tannin, then CCA; 4) TEM/EDAX studies on CCA loadings in the S2 layer of tannin/CCA treated Pinus radiata tracheids. Our observations suggest that by themselves tannins have a minor influence on field performance of CCA-treated hardwoods.
K G Ryan, D V Plackett


Copper naphthenate-treated Southern Pine pole stubs in field exposure. -Part 2: Chemical characterization of full size pole stubs 12 years after treatment
2000 - IRG/WP 00-30246
This study examines the influence of pre-treatment and post-treatment steaming on the character and physio-chemical nature of copper naphthenate in hydrocarbon solvent treated pine in larger, pole diameter, pole stub-length samples. This work is the continuation of two projects that began almost a decade ago. Previous reports indicated that certain morphological changes might occur in small laboratory steamed samples of copper naphthenate treated southern pine. Toluene-methanol extraction, UV-Vis spectroscopy, X-ray diffraction (XRD) and environmental scanning electron microscopy (ESEM) were used to investigate the nature and properties of the copper naphthenate present in the wood after 12 years of exposure. The formation of solid cuprous oxide occurred regardless of pre- or post-steaming conditioning.
H M Barnes, D P Kamdem, M H Freeman


The distribution of introduced acetyl groups and a linseed oil model substance in wood examined by microautoradiography and ESEM
2000 - IRG/WP 00-40169
Microautoradiography, a photographic method that shows the localization of substances labelled with radioactive isotope, and Environmental Scanning Electron Microscopy (ESEM) were combined to enhance sensitivity, resolution and reliability for examination of the distribution of introduced substances in wood. The preparation of microautoradiographs is less complicated when investigated with ESEM and the preparation of ESEM-samples is quick and easy compared to a conventional SEM. When investigating microautoradiographs with ESEM, the wood structure is observed underneath the almost transparent photographic film. Silver grains, indicating the location of studied substances, are clearly distinguish from the wood material. The technique was used in two case studies for examination of cell wall penetration and distribution in pine sapwood. The distribution of acetyl groups, introduced by acetylation with acetic anhydride, and the distribution of a linseed oil model substance, triglycerol trioleate, were examined. Examinations of introduced acetyl groups showed an even distribution of acetyl groups in the wood cell wall at acetylation level of about 5, 15 and 20% (weight gain). Examination of the linseed oil model substance, glycerol trioleate, showed the presence of the model substance on applied surfaces, in rays and in lumen of some latewood cells. No cell wall penetration was observed.
M Rosenqvist


Destruction of wood and mangrove vegetation by marine borers in Goutami-Godavari estuary, east coast of India
1993 - IRG/WP 93-10021
This paper deals with the nature and extent of destruction caused by marine boring organisms to wood and mangrove vegetation in the Goutami-Godavari estuary along the east coast of India. Fifteen species, comprising of 11 teredinids, 1 pholad and 3 sphaeromatids were recorded from the area. For the first time, seasonality of recruitment, abundance and growth were studied for important species occurring at 2 Stations in port Kakinada, a fast developing intermediate port located in the estuarine system. Bankia carinata (Gray) and Bankia campanellata, Moll and Roch are dominant species at Station I, where low and fluctuating salinity conditions prevail. At Station II, where more stable conditions exist, Teredo furcifera Von Martens, Lyrodus pedicellatus (Quatrefages) and Martesia striata (Linne) are important. In the mangrove area (of approx. 30,000 ha), damage is mainly caused by Dicyathifer manni (Wright), Nototeredo edax (Hedley), Lyrodus pedicellatus; Bankia campanellata and Sphaeroma annandalei Stebbing. Factors, especially salinity, which play a significant role affecting abundance and distribution of these organisms are discussed.
K S Rao, L N Santhakumaran, M Balaji, V V Srinivasan


Inhibition of Basidiospore Germination by Copper from MCQ, ACQ and CCA Leachates
2012 - IRG/WP 12-10778
The long-term decay resistance of refractory wood shell-treated with chromated copper arsenate (CCA) in above-ground exposures has been attributed to mobile copper that migrates into checks and inhibits the germination of basidiospores. Copper from micronized copper quat (MCQ) has also been shown to migrate into checks suggesting similar performance as a shell treatment, but questions have been raised about the form of this mobile copper. The concern was that if the copper is present as small particles rather than ions, it might not provide protection against basidiospore germination. The present work examined checks on MCQ-treated boards exposed above-ground in Vancouver for one year using Environmental Scanning Electron Microscopy (ESEM) with energy dispersive X-ray spectroscopic mapping. The copper detected on checks from MCQ-treated wood was not present as micro- or macro-particles. ESEM and EDS data were consistent with the vast majority of detected copper being soluble copper adsorbed to the wood, but did not preclude the presence of some copper-containing nano-particles below 9 nm. In addition, a laboratory test evaluated the efficacy of leachates from treated wood on spore germination. Untreated spruce disks were attached to wood treated with ACQ, MCQ or CCA for up to 36 days under conditions of periodic water spray and high humidity. These disks were used for either copper analysis or spore germination testing against Gleophyllum sepiarium and Oligoporus placentus. After eight weeks of incubation, spores had germinated on most of the untreated controls and on most of the disks previously attached to ACQ-treated wood. Disks previously stored adjacent to MCQ- and CCA-treated wood were largely free of spore germination. These data suggest that the mobile copper from MCQ is effective against basidiospore germination, and that the mobile copper from ACQ may be less effective under the test conditions in this study.
R Stirling, J Drummond, P I Morris