Treesearch

Fine wood powders have advantages over traditional coarse wood particles for various emerging applications. However, an efcient system to produce fne wood powders has not been well established. We investigated the comminution capability and efciency of a two-stage grinding system consisting of a hammer mill circuit and an rotor impact mill circuit to convert wood feedstocks into fne powders. Air-dried forest harvest residuals were comminuted by the hammer mill circuit to three intermediate product sizes with geometric mean particle sizes of 1618, 669, and 316 μm. These intermediate...

A three-stage wood milling process was investigated leading to coarse, fine and amorphization of milled wood (MW) as a pretreatment for enzymatic wood hydrolysis. An eccentric vibratory tube mill (EVTM) and a spring suspended vibratory tube mill (SSVTM) were found to be suitable for wood cellulose amorphization. Both methods gave rise to highly digestible and amorphous wood powders amenable to enzymatic hydrolysis. The SSVTM had superior energy efficiency. The resulting MW afforded a 70% sugar yield via enzymatic hydrolysis and the total energy consumption was around 1.5 kWh kg−1 oven-dried...

Although formaldehyde emissions from interior wood products have been extensively studied, emissions of other volatile organic compounds (VOCs) have received less attention, and engineered products are seldom study. Thus, thirteen commercially–bonded engineered wood products (structural plywood, oriented strandboard, structural composite lumber, I–joists, and glued–laminated timber) from North America were evaluated for VOCs using methods developed for interior bonded wood products. The dominate volatiles for the different products were greatly dependent on wood species and bonding process...

The yeast microorganisms associated with Camponotus vicinus are discussed. Experiments where worker ants and larvae were fed holidic or nutrient deficient diets and then exposed to the yeast, Debaryomyces polymorphus showed that pupal weight was sometimes positively affected by exposure to D. polymorphus. It is speculated that the yeast may aid in more efficient assimilation of nutrients when fed nutrient-deficient diets, particularly diets lacking sterols.

Plant-derived cellulose nanofibrils (CNFs) have shown reinforcing effects in polymer nanocomposites. However, freeze-dried CNFs are foam-like material, namely aerogel, that are challenging to disperse in a polymer matrix. In this work, a liquid infusion process was developed for a CNF/epoxy nanocomposite cross-linked foam structure with alterable properties without damaging the foam structure. Microstructures of CNF/epoxy composite foams with different formulations were evaluated using a scanning electron microscope. Surface morphology showed that the CNF cross-linked fibers were well...

Storage is the critical operation within the biomass supply chain to reduce feedstock supply risks and to manage smooth year-around operations of a biorefinery or a bioenergy plant. This paper analyzed the economic and environmental impacts of four different biomass storage systems for woodchips (Outdoor-open, Outdoor-tarped, Indoor, and Silo) and two systems for pellets (Indoor and Silo). Storage cost includes the costs for handling (including ventilation in case of silo storage), infrastructure investment, and dry matter loss (DML) for each system. The estimation of total greenhouse gas...

Statistical process control (SPC) is an important strategy for manufacturing organizations seeking improved profitability in highly competitive businesses such as the treated wood industry. SPC is a well-established methodology that focuses on reducing variation of key process parameters. Such variation reduction can result in lower manufacturing costs, improved product quality, and enhanced environmental stewardship. This paper outlines a protocol for establishing SPC for the treated-wood industry.

Although alternative control strategies using biocontrol agents have reduced populations of many pest insects, biocontrol of termites has met with limited success. Termite living conditions—crowded colonies in moist soil—are seemingly ripe for epizootic outbreaks, yet, termite colonies rarely succumb to disease. The source of their immunity comes from a multi-tiered defense system involving cellular, physiological, and behavioral mechanisms, the combination of which protects termites at individual and colony levels. Defeating termite immunity, however, may be possible by chemically...

Although protist species composition in the hindgut of subterranean termites is known to vary among termite species, less is known about the effects of biocides on protist population dynamics within a single species. The goal of this study was to observe the potential effect of chitosan, an environmentally friendly antimicrobial compound, on protist communities harbored in hindguts of Reticulitermes virginicus. Workers of two termite colonies collected from different locations were exposed to treated wood with different concentrations of chitosan (0.5%, 1% and 2%) and two sets of control-tr...

Bark beetle outbreaks are increasing in frequency and intensity, generating massive inventories of dead trees globally. During attacks, trees are pre-inoculated with ophiostomatoid fungi via bark beetles, which has been shown to increase termite presence and feeding. These events may, in turn, alter biogeochemical cycles during decomposition. We examined these relationships by experimentally inoculating dead wood with bluestain fungi in a temperate pine forest. Across ten replicate plots, eight 0.5 m-long logs were inoculated with Ophiostoma minus and eight with distilled water. Half of...