Treesearch

This study evaluated the potential of acoustic analysis as presorting criteria to identify warp-prone boards before kiln-drying. Dimension lumber, 38 by 89 mm (nominal 2 by 4 in.) and 2.44 m (8 it) long, sawn from open-grown small-diameter ponderosa pine trees, was acoustically tested lengthwise at green condition. Three acoustic properties (acoustic speed, rate of wave attenuation, and acoustic modulus of elasticity (MOE)) were then determined through waveform analysis. Boards were then kiln-dried, and warp was measured immediately after drying and after equilibrating to about 13%...

The mineral scale that deposits in digesters and bleach plants is formed by a chemical precipitation process.As such, it is accurately modeled using the solubility product equilibrium constant. Although solubility product identifies the primary conditions that must be met for a scale problem to exist, the acid-base equilibria of the scaling anions often control where in the process scale will occur. These equilibria are the primary control method to minimize or prevent scale in a bleach plant. Both the acid-base equilibria and solubility product equilibria are influenced by temperature and...

Whereas many research activities focus on developing value-added processes that use forest residues, scientists must also investigate the mechanical properties of products made from recycled fiber resources. This study compared the tensile and bending properties of binderless panels made from recycled corrugated containers with properties of panels made from lodgepole pine treetop residues. The properties were measured after reaching equilibrium moisture contents in 50 and 90 percent relative humidity environments. The results show panels made from recycled corrugated containers at both...

Heat sterilization is used to kill insects and fungi in wood being traded internationally. Determining the time required to reach the kill temperature is difficult considering the many variables that can affect it, such as heating temperature, target center temperature, initial wood temperature, wood configuration dimensions, specific gravity, and moisture content. In this study, the time required to heat the center of round, square, and rectangular wood members in saturated steam was calculated by using heat conduction equations for a number of combinations of these variables. The...

Although there are numerous techniques available to study lignin in its various states, they all have limitations and to extract most amount of information, a number of analytical techniques have to be jointly used. We have recently started applying a new approach to lignin analysis - namely using nano- and micro-particles of silver for study of native and residual lignins by surface enhanced Raman spectroscopy (SERS). Silver particles were used for their unique electronic and optical properties (in this case, localized surface plasmon resonance). The SERS technique is highly sensitive and...

The white rot basidiomycete Phanerochaete chrysosporium produces an array of nonspecific extracellular enzymes thought to be involved in lignin degradation, including lignin peroxidases, manganese peroxidases, and the H2O2-generating copper radical oxidase, glyoxal oxidase (GLX). Preliminary analysis of the P. chrysosporium draft genome had identified six sequences with significant similarity to GLX and designated cro1 through cro6. The predicted mature protein sequences diverge substantially from one another, but the residues coordinating copper and constituting the radical redox site are...

Boreal forests support an array of insects, including phytophagous (plant-eating) insects, saprophagous (detritus-eating) insects, and their associated parasites, predators, and symbionts. The phytophagous species include folivorous leaf chewers and miners, phloeophagous cambial and sapwood borers, stem gallers, and root feeders. Biological diversity and distribution of insect species exhibit predictable patterns among vegetation types (Werner 1994a). In this chapter, we discuss how phytophagous species of insects differ among plant communities and how various populations of insects react...

\tPulp and paper markets in the UNECE region were influenced by higher energy prices and demand growth in Asia in 2005 and 2006. Important developments in Europe included the launching of the EU Emissions Trading Scheme, which was followed by substantial increases in electrical energy prices. High global energy prices pushed up costs of production and prices for pulp, paper and paperboard, with price increases absorbed by relatively strong global market demands. China continues to be a growing source of global demand for wood fibre, including recovered paper, which China imports in large...

Nonnative organisms that cause a major change to native ecosystems-once called foreign species, biological invasions, alien invasives, exotics, or biohazards–are now generally referred to as invasive species or invasives. invasive species of insects, fungi, plants, fish, and other organisms present a rising threat to natural forest ecosystems worldwide. Invasive animals are transferred to ecosystem in which there are no natural predators to keep them from spreading. Many species escape into the new environment where they become established, upsetting the ecological balance of the native...

The authors have developed technologies for fungal bioremediation of waste wood treated with oilborne or metal-based preservatives. The technologies are based on specially formulated inoculum of wood-decay fungi, obtained through strain selection to obtain preservative-tolerant fungi. This waste management approach provides a product with reduced wood volume and the capacity to collect metals for reuse, thereby preventing environmental contamination. In this chapter we describe our research on the bioremediation of CCA-treated wood waste with brown-rot wood-decay fungi. The paper contains...