Treesearch

We grew from seed the exotic invasive annual grass Bromus tectorum L., collected from three elevation ecotypes in northern Nevada, USA. Plants were exposed to four CO2 atmosphere concentrations: 270, 320, 370, and 420 [mu]mol mol−1. After harvest on day 87, above-ground tissue was milled, conditioned to 30% relative humidity, and combustion properties were measured using a cone calorimeter. Plants exposed to 270 ìmol mol−1 CO2 had significantly less total heat released than plants exposed to higher CO2 concentrations. Total heat released was least for the low-elevation ecotype, statisticall...

When wood and wood products are exposed to moisture during storage, construction or while in-service, mold growth can occur in 24 to 48 hours. Mold growth could be suppressed or prevented if wood was treated with an effective mold inhibitor. The objective of this study was to evaluate the mold inhibiting properties of natural plant extracts such as essential oils. Seven essential oils were evaluated for their ability to inhibit growth of Aspergillus niger, Trichoderma viride, and Penicillium chysogenum on Southern yellow pine (SYP) specimens that were either dip- treated or exposed to...

Environmental pressure has resulted in voluntary removal of chromated copper arsenate (CCA) from wood preservatives in residential applications in the United States. A new generation of copper organic preservatives was formulated as replacements, but these preservatives may not provide a permanent solution to all related problems. Some of these issues include concern over copper in aquatic environments and corrosion of fasteners. Copper preservatives in general are also poor inhibitors of mould. Therefore, we still need to evaluate alternative solutions in order to address current inadequac...

The Hampton Affiliates sawmill in Willamina, Ore. again tops the list for output by a single U.S. mill for 2005. Its 486 MMBF not only outdid some 660 other significant US. sawmills, but also its own production of 473 million in 2004. Only a few mills in British Columbia and Germany are in this volume range. This marks the fourth consecutive year that Hampton’s Willamina mill has won the “national title.”

A detailed understanding of the structural organization of the cell wall of vascular plants is important from both the perspectives of plant biology and chemistry and of commercial utilization. A state-of-the-art 633-nm laser-based confocal Raman microscope was used to determine the distribution of cell wall components in the cross section of black spruce wood in situ. Chemical information from morphologically distinct cell wall regions was obtained and Raman images of lignin and cellulose spatial distribution were generated. While cell corner (CC) lignin concentration was the highest on...

Wood preservation can be interpreted to mean protection from fire, chemical degradation, mechanical wear, weathering, as well as biological attack. In this chapter, the term preservation is applied more restrictively to protection from biological hazards.

Wood flour and fiber have been blended with thermoplastic such as polyethylene, polypropylene, polylactic acid and polyvinyl chloride to form wood plastic composites (WPC). WPCs have seen a large growth in the United States in recent years mainly in the residential decking market with the removal of CCA treated wood decking from residential markets. While there are many successes to report in WPCs, there are still some issues that need to be addressed before this technology will reach its full potential This technology involves two different types of materials: one hygroscopic (biomass)...

This paper presents FTM–West, a partial market equilibrium model designed to project future wood market impacts of significantly expanded fuel treatment programs that could remove trees to reduce fire hazard on forestlands in the U.S. West. FTM–West was designed to account for structural complexities in marketing and utilization that arise from unconventional size distributions of trees and logs removed in fuel treatment operations as compared with conventional timber supply in the West. For example, tree size directly influences market value and harvest cost per unit volume of wood,...

Our analytical model of fire growth for the ASTM E 84 tunnel, which simultaneously predicts heat release rate, flame-over area, and pyrolysis area as functions of time for constant conditions, was documented in the 2001 BCC Symposium for different treated wood materials. The model was extended to predict ignition and fire growth on exterior fire-resistive structures and ornamental vegetation for an efficient assessment of fire hazard in the wildland-urban interface. The improved model accommodates the following changing conditions: (1) transient variation of imposed heat fluxes in pyrolysis...

The majority of the barium present in the pulping process exits the digester as barium carbonate. Barium carbonate dissolves in the bleach plant when the pH drops below 7 and, if barium and sulfate concentrations are too high, begins to precipitate as barium sulfate. Barium is difficult to control because a mill cannot avoid this carbonate-to-sulfate transition using common bleaching technology. An advantage in controlling barium scales is that the sulfate, once formed, will not redissolve to any appreciable extent, and this reduces the rate at which barite scale can form in other locations...