Treesearch

The objective of this study was to explore the potential of an acoustic impact test as a nondestructive evaluation procedure to assess the soundness of hardwood logs in terms of internal decay, void, and defect ratio. Fifteen logs of four hardwood species (black cherry, white oak, red oak, and cottonwood) were obtained and subjected to acoustic impact testing. The logs were subsequently dissected for visual examination and physical mapping of the internal defects. The acoustic response signals were analyzed to derive acoustic velocity (through FFT), time centroid (through moment analysis),...

This Research Note describes the rationale for and design of a XyloScope, a digital imaging system for viewing and recording macroscopic images of wood for a XyloTron machine-vision wood identification system, and provides a bill of materials and the associated technical drawings of its components.

The use of cross-laminated timber (CLT) as a building material is gaining popularity in the North American building sector, especially in mid- to high-rise building designs. This study presents the methodology of life-cycle cost analysis (LCCA) and an example of a hypothetical case study in Portland, Oregon, USA, of a CLT mass timber building compared with a baseline code-compliant concrete alternative. It was found, not unexpectedly, that the mass timber building with premium energy and water saving designs exhibited a lower total life-cycle cost (TLCC) than a concrete building for a...

Global demand for construction materials has grown greatly in the last century, contributing to unsustainable growth and detrimental impacts on the ecosystem. To aid in sustainable growth and reduce our environmental footprint, renewable construction materials, such as lumber, have been incorporated into green building activities. To quantify the environmental footprints of construction products, a method called life-cycle assessment is used. This study determined the environmental attributes associated with manufacturing redwood lumber in northern California using the unit process...

Buckling Restrained Brace Frames (BRBF) are a proven and reliable method to provide an efficient lateral force resisting system for new and existing structures in earthquake prone regions. The fuse-type elements in this system facilitate stable energy dissipation at large load deformation levels. Currently, the new trend towards mass timber vertical structures creates a need for a lightweight compatible lateral force resisting system. A Buckling Restrained Brace (BRB) component is possible to construct and feasible to implement when combining a steel core with a mass timber casing herein...

Fungi that decay wood have characteristic associations with certain tree species, but the mechanistic bases for these associations are poorly understood. We studied substrate-specific gene expression and RNA editing in six species of wood-decaying fungi from the ‘Antrodia clade’ (Polyporales, Agaricomycetes) on three different wood substrates (pine, spruce, and aspen) in submerged cultures. We identified dozens to hundreds of substrate-biased genes (i.e., genes that are significantly upregulated in one substrate relative to the other two substrates) in each species, and these biased genes...

This paper reports a facile one-pot method to produce graphene oxide nanocellulose composite (GNCC) that was subsequently reduced using L-ascorbic acid to form a conductive paper (CP). Cellulose fbers were directly added into the reaction system during graphite exfoliation using sulfuric acid to produce cellulose nano- or microfbrils through acid hydrolysis along with mechancial mixing. FTIR and Raman analyses indicated that reduction using L-ascorbic acid efciently produced a welldeoxygenated CP with high conductivity of 116.3±1.5 S m−1 at 20% graphene oxide loading. Furthermore, the...

This study evaluated the solubility of low-processed wood fibers produced from a low temperature acid hydrotropic fractionation (AHF) in an ionic liquid (IL) 1,5-diazabicyclo[4.3.0]non-5-enium acetate (DBNH[OAc]. Unbleached wood fibers produced from AHF using p-Toluenesulfonic acid (p-TsOH) with or without post-treatments with lignin and hemicelluloses content up to 15% and 25%, respectively, were dissolved directly into the ILDBNH[OAc]. Post-AHF treatments using dilute alkaline and glycerol swelled the cellulose and partially removed residual lignin resulting in improved dissolution....

Microstickies present a formidable challenge for papermakers. Many strategies have been explored to control them. Enzyme treatment is a promising technology, but the mechanism of its action has not been determined, thus inhibiting further application of this new technology. This study investigated characteristics and size distributions of microstickies treated by esterase-cellulase mixtures. Determination of particle size and number was accomplished using a modified flow cytometer, which combined streaming capillary flow, laser-based particle size analysis and fluorescent dye tracing. The...

In this study, 145 poplar (Populus × euramericana cv.’74/76’) seedlings, a common plantation tree species in China, were selected and their ultrasonic velocities were measured at four timepoints during the frst growth year. After that, 60 poplar seedlings were randomly selected and cut down to determine their acoustic velocity, using the acoustic resonance method. The effects of infuencing factors such as wood green density, microfbril angle, growth days, and root-collar diameter on acoustic speed in seedlings and the relationship between ultrasonic speed and acoustic resonance speed were...