Treesearch

This report examines economic implications for sustainable forest management of globalization and related structural changes in the forest sector of the United States. Globalization has accelerated structural change in the U.S. forest sector, favored survival of larger and more capital-intensive enterprises, and altered historical patterns of resource use.

This paper describes the removal of extraneous color from increment cores of conifers prior to reflected-light image analysis of tree rings. Ponderosa pine in central New Mexico was chosen for study. Peroxide bleaching was used as a pretreatment to remove extraneous color and still yield usable wood for image analysis. The cores were bleached in 3% peroxide raised to pH 12 and heated to 60° C, and then they were soaked in 95% ethanol and rinsed in water. The cores were dried slowly to avoid checking or cracking. This treatment removed heartwood color while leaving the wood reasonably...

In developing new adhesives for wood bonding, the testing of bond performance can often be a limiting factor in the development process. Evaluating the bond performance of an adhesive that can be prepared in less than a day often takes several days using standard performance tests. This testing slows the development process and may cause a company to abandon a commercially viable product due to development costs or to offer a product commercially that has not been fully developed. Furthermore, some of the standard tests provide only qualitative data on a pass/fail basis, making it difficult...

Higher petroleum prices and greater interest in bio-based adhesives have stimulated a considerable amount of research on incorporating soybean flour into wood adhesives in recent years. In some cases, soy was used at low levels as an extender for phenol-formaldehyde (PF) adhesives; in other cases, highly hydrolyzed soy flour was used. Although progress was made in getting soy to react with PF, incorporation of the soy was still fairly low. Addition of the flour to hot aqueous caustic, followed by stabilization of the alkaline soy mixture by reaction with formaldehyde, was a recent key step...

Biorefining wood into paper and chemicals is not as easy as making a single traditional paper product. Paper is made from the cellulose- containing fractions of wood and processing may remove lignin and hemicellulose components. The yield and composition of the product depend upon the type of paper being produced. The paper process often alters the noncellulose fractions, making them less suitable for conversion to other valuable products. This chapter will review methods of obtaining hemicellulosic sugars and investigate the potential for obtaining sugars by a wood pretreatment before it...

To reduce the risk of catastrophic fires, the USDA Forest Service and its partners are developing practical, economic uses for forest thinnings from National Forests and state and private lands in western states. Because mechanical thinning is costly, developing markets for removed wood as fuel for community energy applications is one way to support the economics of forest management while saving money for communities. By installing a wood heating system in the public schools in Darby, Montana, the Fuels for Schools Program is demonstrating the potential of putting low quality wood...

Acoustic wave velocities in standing trees or live softwood species were measured by the time-of-flight (TOF) method. Tree velocities were compared with acoustic velocities measured in corresponding butt logs through a resonance acoustic method. The experimental data showed a skewed relationship between tree and log acoustic measurements. For most trees tested, observed tree velocities were significantly higher than log velocities. The results indicate that time-of-flight measurement in standing trees is likely dominated by dilatational or quasi-dilatational waves rather than one-dimensiona...

Bark flour from ponderosa pine (Pinus ponderosa) was consolidated into pellets using citric acid as cross-linking agent. The pellets were evaluated for removal of toxic heavy metals from synthetic aqueous solutions. When soaked in water, pellets did not leach tannins, and they showed high adsorption capacity for Cu(ll), Zn(ll), Cd(ll). and Ni(ll) under both equilibrium and dynamic adsorption conditions. The experimental data for Cd(ll) and Zn(ll) showed a better fit to the Langmuir than to the Freundlich isotherm. The Cu(ll) data best fit the Freundlich isotherm, and the Ni(ll) data fitted...

A qualitative test that mimics the corrosion behaviour of metals in contact with treated wood without using wood specimens would be of great value in rapidly evaluating the corrosiveness of new wood preservatives. The objective of this study was to determine whether the linear polarisation resistance of metals immersed in a solution of preservative chemicals is related to corrosion of metals in wood. This technique was used to measure the corrosion rate of four types of metals in three different aqueous solutions of wood preservatives. The four metals were UNS G10180 (SAE 1018 steel), UNS...

In this study the capacity of sorbents prepared from juniper wood (JW) and bark (JB) to adsorb cadmium (Cd) from aqueous solutions at different pH values was compared. Adsorption behavior was characterized through adsorption kinetics, adsorption isotherms, and adsorption edge experiments. Results from kinetics and isotherm experiments showed that JB (76.3–91.6 lmol Cd g_1 substrate) had 3–4 times higher adsorption capacity for Cd than JW (24.8–28.3 lmol Cd g_1). In addition to higher capacity, JB exhibited a higher strength of adsorption (45.3 versus 9.1 L mmol_1) and faster uptake...