Treesearch

The phase reaction conversion (PRC) headspace gas chromatographic (HSGC) technique was employed to develop a method for the determination of the content of carboxyl groups in wood fibers. Acid treatment of the wood fibers using hydrochloric was applied to convert carboxyl groups to carboxyl acids. Bicarbonate solution is then used to react with carboxyl acids on the treated fibers in the headspace of a testing vial to form carbon dioxide that is analyzed by a thermal conductivity detector using gas chromatography. The conversion reaction was conducted at 60oC for about 10 minutes to...

Options for recycling and reusing chromated-copper-arsenate- (CCA) treated material include dimensional lumber and round wood size reduction, composites, and remediation. Size reduction by remilling, shaving, or resawing CCA-treated wood reduces the volume of landfilled waste material and provides many options for reusing used treated wood. Manufacturing composite products from CCA-treated wood combined with untreated wood, plastic, or cement has been explored. Remediation strategies are numerous; chemical extraction, bioleaching, chelation, and liquefaction or a combination of these...

It has been found that polyoxometalates (POMs) can act as mediators in the electrochemical oxidation of lignin in pulps. An electrochemical cell, with a Nafion® membrane separating the anode and cathode compartments, was used in the delignification experiments. A softwood kraft pulp was placed in the anode compartment with a buffered 0.01M solution of the polyoxometalate Na5[SiVW11O40]. During electrolysis the lignin content of the pulp was reduced from kappa number 26 to 6. The energy required for this delignification was equivalent to 120 kW·hr per ton of pulp. At $0.05/ kW·hr, the cost...

Because radiata pine has thrived in south-central Chile since it was introduced there more than a century ago, pine plantation productivity there has grown tremendously. Plantation owners are seeking new markets for this material. One potential market is utility poles. The American National Standards Institute 05.1 standard (ANSI 05.1) provides a means for radiata pine to be recognized as a viable pole species. Before radiata pine can be accepted into ANSI 05.1, test data must be provided to support the ANSI-designated fiber stress. This studypresents an evaluation of radiatapine poles...

The principal wood preservative for residential use is currently a broad-spectrum biocide which contains As, Cr and Cu. However, the use of totally organic wood preservative systems in certain applications or localities may be required in the future. This will greatly increase the price of treated wood. The combination of organic biocides with non-biocidal additives to give enhanced efficacy is one possible means to lower the cost of future wood preservative systems. Possible non-biocidal additives which could be mixed with organic biocides include water repellents, antioxidants, and...

Early detection of wood decay can prolong the service life of wood. Antibodies are the ideal probe for detecting fungi that cause biodeterioration because they are highly specific and can quantitatively determine the fungal antigen concentration from highly complex structures, such as wood. Polyclonal antibodies recognize multiple chemical sites of the targeted molecule, in our case, a fungal glycoprotein, while monoclonal antibodies recognize one specific protein sequence on the targeted molecule. Both polyclonal and monoclonal antibodies have been utilized separately or in concert to...

Several non-intrusive synchrotron techniques are being used to detect and study wood decay. The techniques use high intensity synchrotron-generated X-rays to determine the atomic structure of materials with imaging, diffraction, and absorption. Some of the techniques are X-ray absorption near edge structure (XANES), X-ray fluorescence spectroscopy (XFS), X-ray absorption fine structure (EXAFS), and X-ray computed microtomography (XCMT). Micro-fluorescence spectroscopy was used to map the accumulation and spatial distribution of elements around hyphae at the site of decay. MicroXANES...

About 160 fewer softwood sawmills are operating in the United States and Canada than were 8 years ago. Nevertheless, the combined capacity of the remaining mills has increased by 16%, to over 173 million cubic meters. Of the approximately 1,140 mills, about 470 characterize their output as dimension lumber, accounting for 67% of capacity; 136 list studs as their primary output, representing 16% of the industry's volume; and 139 are primarily board mills, making up a little over 5%. The others make a variety of specialty products. In this report, the location and relative size of sawmills...

Urban tree and woody yard residues are an important component of the municipal solid waste (MSW) stream in the United States. In 2000, approximately 14.5 million tons of urban tree and woody yard residues was generated, nearly 7% of total MSW. Some woody residues are being recovered for recycling, composting, or other uses, but a large proportion is simply discarded. In total, urban tree and woody yard residues form a resource about as large or larger than the current timber harvest from National Forests. Materials from each of these two sources have distinctly different properties and, in...

Wood-plastic lumber is promoted as a low maintenance high-durability product. When exposed to accelerated weathering, however, wood-plastic composites may experience a color change and/or loss in mechanical properties. Different methods of manufacturing wood-plastic composites lead to different surface characteristics, which can influence weathering, In this study, 50% wood-flourfilled high-density polyethylene (HDPE) composite samples were injection molded, extruded, or extruded and then planed, to remove the manufacturing surface characteristics. Fourier transform infrared spectroscopy...