Treesearch

With the move to intensive forest management to meet wood demand and to preserve the environment, south­east Alaska is experiencing a period of significant change in terms of wood characteristics or wood quality. In order to responsibly manage the young-growth stands, it is im­portant to evaluate tree quality prior to harvest and un­derstand the product and economic potential of the wood fiber in standing trees. The research reported in this pa­per is a component of a larger wood quality project that was designed to address the quality concerns on the young-growth wood in southeast Alaska...

Acoustic velocity was measured with a time-of-flight method on approximately 50 trees in each of five plots from four test sites of a Douglas-fir (Pseudostuga menziesii (Mirb.) Franco) thinning trial. The test sites reflect two age classes, 33 to 35 and 48 to 50 years, with 50-year site index ranging from 35 to 50 m. The acoustic velocity distribution in each plot formed the basis for selecting a stratified sample of 12 trees that were harvested for conversion into veneer or lumber. Using a resonance acoustic method, acoustic velocity was obtained for the delimbed and topped merchantable...

P. stipitis has been a source of genes for engineering xylose metabolism in Saccharomyces cerevisiae—a task that has been undertaken in numerous laboratories around the world (Jeffries and Jin, 2004). Much less effort has gone into engineering P. stipitis for improved xylose metabolism. In addition to genes for xylose assimilation, P. stipitis possesses the regulatory machinery that enables the efficient conversion of xylose under oxygen limited conditions. While such engineering is conceivable, alteration of transcriptional regulators and cis-acting factors could be very difficult. P....

Forward genetic mutational studies, adaptive evolution, and phenotypic screening are powerful tools for creating new variant organisms with desirable traits. However, mutations generated in the process cannot be easily identified with traditional genetic tools. We show that new high-throughput, massively parallel sequencing technologies can completely and accurately characterize a mutant genome relative to a previously sequenced parental (reference) strain. We studied a mutant strain of Pichia stipitis, a yeast capable of converting xylose to ethanol. This unusually efficient mutant strain...

Approximately 375 Douglas-fir and ponderosa pine logs, 3 to 6 inches in diameter, were tested in third-point bending and in compression parallel to the grain. The moisture content at time of test was about 14 percent. Good correlations were found between the modulus of elasticity (MOE) in static bending and those obtained by transverse vibration. Good correlations were also found between modulus of rupture (MOR) and MOE. A species independent relationship was established between ultimate compression stress parallel to the grain and MOR. A mechanical grading system previously developed for...

Manure, an animal waste product with many negative economic and environmental issues, can today be converted using anaerobic digestion technology into a number of commercial products ranging from fertilizer, compost, animal bedding, and plant bedding. A number of new uses are now being explored such as bioenergy (both electrical and biofuel) and a lignocellulose-rich potential feedstock for engineered biocomposite products for building materials. This paper explores the engineering potential of using anaerobically digested bovine biomass (ADBF) as a feedstock material for biocomposite...

Improvements to housing will require both research and the transfer of that research to homebuilders, homebuyers, and others in need of technology. This report summarizes results of a national survey on research and technology transfer needs for housing and prioritizes those needs. Survey participants included academicians, builders, code officials, government officials, homeowners, manufacturers, and others. In addition to determining overall priorities, research and technology transfer needs are also categorized into important priority areas for housing: construction, design, disaster,...

The historic American ship WAPAMA is the last surviving example of the wooden steam-powered schooners designed for the 19th- and 20th-century Pacific Coast lumber trade and coastal service. Since its launching in 1915, the WAPAMA has had a long and productive life in plying cargo and passengers along the stormy West Coast from Mexico to Alaska. As the sole survivor of the once numerous class, the WAPAMA was declared a National Historic Landmark in 1984. The wood structure of the WAPAMA has significantly deteriorated over the years and currently resides on a barge with internal and external...

A vast wood resource exists in our Nation's wood-framed building infrastructure. As the buildings in this infrastructure age and are remodeled or removed for redevelopment, the wood framing residing in these buildings has the potential to be recovered for reuse. However, little technical information exists on the residual engineering properties of reclaimed dimensional lumber. Our study was undertaken to quantify the engineering strength and stiffness of dimensional Douglas-fir 2-by lumber recovered from building dismantlement or deconstruction. These data can serve as a basis for establish...

This paper explores the physical and economic potential to substitute anaerobically digested bovine biofiber (ADBF) for wood in the making of particleboard. Laboratory tests indicated that replacement of one-half the wood in particleboard with ADBF produced panels that compared favorably to the requirements for commercial particleboard performance (specified by ANSI Standard A208.1-1999). The economic question hinges on the opportunity costs of alternative uses for ADBF. The current use is primarily animal bedding, and prices appear to be greater than those paid by particleboard plants for...